I have been working with my dad on his cancer treatment since last year. My interest in the topic has only peaked ever since.
(Disclaimer- I am an engineer and not a microbiologist/doctor)
Mutations and wrong copying of genome happens all the time in the body and some enzyme has the job of correcting the mutated genes so it doesn’t get into the system. Level 2 defence is T cells killing it as identified as foreign body.
Thing that baffles me is that I see most work happening to eliminate tumor. To me it sounds a tough problem given the permutation and combination of mutation— roughly few trillions.
But I was curious if there is working happening on L1 defence — fixing the enzyme that fixes the wrong copy paste mechanism. Or making the enzyme get more efficient and powerful. Is that line of thought even valid?
Our L1 defense is actually incredibly good. A human will undergo about 10^16 cell divisions over the course of their lifetime. Around 10^3 to 10^6 of those divisions will result in a mutation that gets past the L1 defenses and need to be eliminated by the T cells. It's not generally easy to make dramatic improvements to something with a 99.9999999% success rate.
The immune system is pretty good too, which means any given improvement to the replication system is, all else being equal, probably going to prevent mutations the T cells would already handle. If you need to do the research to figure out what's getting past the immune system anyways, and improving the immune system is lower hanging fruit, it's the logical place to start.
This is a fascinating niche of evolutionary biology that I have worked in for a while. The short answer is that yes, as far as we can tell all organisms evolve increasingly more efficient replication machinery, however at some point the strength of selection is no longer powerful enough to overcome the strength of genetic drift and some degree of error rate persists. As far as we can tell it seems like population size governs where this balance ends up such that small populations have high mutation rates and large populations have reduced mutation rates. Michael Lynch coined the term drift barrier hypothesis to describe this phenomenon. https://pubmed.ncbi.nlm.nih.gov/23077252/
Yes, but note the mutation rate of germline cells - that are passed to your offspring and hence influence evolution - is estimated to be two orders of magnitude lower than other (somatic) cells.
Not necessarily if it had recombination (as in sexual reproduction), but as far as I understand, yes, you’d probably get fewer novel alleles/coding sequences of DNA generated per organism replication
While cancer is caused by mutations in the genome, these mutations in turn produce the unifying property of cancer: unchecked cell replication.
Most cell types have systems to safely manage replication. Broadly, there are gas pedals (oncogenes) and brakes (tumor suppressors). A classic oncogene is something like RAS, which activates a signaling cascacde and stimulates progression through the cell cycle. A canonical tumor suppressor is something like TP53, the most frequently mutated gene in cancer, which senses various cellular stresses and induces apoptosis or senescence.
Most cancer genomes are more complicated than individual point mutations (SNPs), insertions, or deletions. There are copy number alterations, where you have > or < 2 copies of a genomic region or chromosome, large scale genomic rearrangements, metabolism changes, and extrachromosomal DNA. There is a series on the hallmarks of cancer which is a useful overview [1].
All of the mechanisms that intrinsically regulate cell growth would fall under your "L1 defense". Unfortunately, the idea of reversing somatic point mutations is likely to be a challenging approach to treating cancer given the current state of technology.
First, for the reasons above, cancer is often multifactorial and it would be difficult to identify a single driver that would effectively cure the disease if corrected. Second, we don't have currently delivery or in vivo base editing technology that is sensitive or specific enough to cure cancer by this means. There are gene therapies like zolgensma[2] which act to introduce a working episomal (not replacing the damaged version in the genome) copy of the gene responsible for SMA. There are also in vivo cell therapies like CAR T which attempt to introduce a transgene that encodes for an anti-cancer effector on T cells. These sorts of approaches may give some insight into the current state of art in this field.
Edit: also I should note that the genes involved in DNA repair (PARP, BRACA1/2, MSH2, MLH1, etc) are frequently mutated in cancers and therapeutically relevant. There are drugs that target them, sometimes rather successfully (e.g. PARP inhibitors). But the mechanisms of action for these therapies are more complicated than outright correcting the somatic mutations.
It starts with mutations (sometimes accelerated by mutagens (smoke, alcohol, etc) or inflammation (viruses, infections, etc) or just chance (things like asbestos up the division rate by constant physical damage and thus up the probability or an error in copying).
But there is much more to it. This is a nice paper for an overview: Hallmarks of Cancer (tng) [0]. It (among others) adds the very important and for years underestimated role of the immune system to the original 2000 paper.
Would sports also increase the rate of division? Bodybuilding for example you intentionally make micro tears in muscles to get them to repair and grow (lay person, apologies for the mistakes)
Also not a doctor or microbiologist, but just wanted to share my layman’s guess on why fixing enzymes will not completely solve the issue: there’s 2 strands of DNA and to fix the broken (mutated) strand you need to have one correct template strand intact so you know what it should be fixed into. It could be the nucleotides swapped places between strands or are deleted completely or otherwise both mutated, which would mean any repair will not revert the sequence to what it used to be.
The other comments so far are probably more informed.
Cancer sucks, I wish all the best towards a recovery.
You’d also have to ‘fix’ DNA: unless we can re-engineer a bunch of key enzymes and then re-encode the entire genome (or maybe key parts) with forward error correction without breaking everything else, it might work. You might also break evolution to some degree by making random point mutations less likely.
But what I learned so far is that as soon as you’d attempt something like this in bacteria, the fitness advantage from an evolutionary standpoint is negligible compared to the efficiency loss introduced by FEC, so your colony would get outcompeted by other bacteria unless there is a niche your resistant bacteria survive in (high radiation environments?). The efficiency loss induced ‘disadvantages’ would probably be less pronounced in mammals though - If (big if) you manage to not also break anything essential in the wonderful yet surprisingly efficient Rube Goldberg machine that is life.
What I meant was there are collection of genes responsible for error correction. If there is a failure in duplication then these genes have not done their job.
Thought experiment, again as a layman, was to see if these genes responsible for error correction at the base level can be fixed or bolstered and that will act like a cancer vaccine. But looks like from other comments that this is even more harder!
> But I was curious if there is working happening on L1 defence — fixing the enzyme that fixes the wrong copy paste mechanism. Or making the enzyme get more efficient and powerful. Is that line of thought even valid?
Mutations in general are not the defining quality of cancer. It's mutations in these very L1 safeguards. There are several such safeguards and a cell needs several mutations in those to become malignant. Eg. https://en.wikipedia.org/wiki/P53
Correcting genes only works in certain conditions (e.g. limited single strand breaks), in a narrow time frame during cell division, safeguards rather trigger cell suicide, or if that fails they mark the cell for destruction by immune cells. A cell can't fix DNA which made it through cell division once, because it got nothing to proof-read against.
After the safeguards are gone, everything goes and genetic diversity increases quickly within each tumor. This diversity is what's making cancer treatment hard. At some point there won't be a shared vulnerability in all malignant cells. The repair mechanisms are working in favor of the cancer now. For example, with radiation therapy you preferably want to induce DNA double strand breaks, because cancer cells can't repair those. Otherwise you need to increase the radical burden enough to overwhelm repair, but migrating radicals may damage distant cells, too.
I presume you could hypothetically inject mRNA of a working safeguard gene (eg. P53) into all cells (at some point cancer cells can't be selected exclusively, since they lost identifying marks and present as stem cells), so the functional enzyme or transcription factor is forced to be built inside. I am sure people are trying this right now. However, the inner workings of cells on a molecular level are insanely complex and our understanding is only scratching the surface. As with P53, you have a transcription factor, which means it's modifying gene expressions elsewhere. It's only a small part of a complex regulatory cascade. I doubt there is a safeguard target, which can easily be injected without considering the precise timing and environment within that safeguard cascade in the cell. Of course, the rest of the safeguard system needs to be present in the cell to begin with. Mind you, you don't want to cause cell suicide in healthy cells, so you want to restore the function of whole complex.
Then there is the question of delivery. Can you deliver eg. the mRNA to every cell without raising suspicion of the immune system? With the COVID vaccine, the enabling breakthrough was the delivery vehicle, not as much the mRNA part. Can you even reach the cancer cells at all? Cancer cells are frequently cloaked, shadowed or cut of by senescent, or necrotic cells, or acquired unique ways of metabolic adaptations.
Life is complex beyond comprehension! Despite simplifications taught in schools, we actually know sooo little about what's going on in genetics and molecular biology, most medical knowledge is empiric guessing instead of explanatory understanding.
L2 is being prioritized because our L1 defences are already very good. We are a long-lived species, and our natural ability to fix errors is so good that it is hard to improve upon. Maybe the long-lived tortoises or whales can do it better, maybe. But we have "several nines of reliability" there.
OTOH our L2 isn't that good, mammals in general (with some notable exceptions such as bats, whales and naked mole rats) are prone to cancer in their older age. There probably is a lot of relatively low-hanging fruit there.
If you think about it - individual cells aren't very precious and if some of them gets FUBARed by something (a virus, radiation or chemical insult), it is better to whack it and reuse the proteins to build a new one, if possible, instead of wasting time and resources on reconstruction of a total wreck.
Which also means that some research into replenishment of stem cells is necessary - and this is, IMHO, the really underfunded part of the whole thing. We lose a lot of stem cells as we age. Maybe we don't have to.
I know this is a bit off topic, but have you ever thought about why steroids and other forms of doping are not a free lunch? Why can't we just inject an external chemical to boost our strength for free without any side effects?
If steroids worked, everyone would be constantly injecting them. It would be like drinking coffee.
And that is the reason why steroid injections are harmful. If there is a free lunch, the human body will simply produce the optimal amount of steroids on its own until the Pareto frontier is reached and a tradeoff needs to be made.
Where does the body get the materials to form the steroids? From your diet. So the primary intervention is always a healthy diet and an active lifestyle. You know, the boring things that parents drill into their children.
It's valid but "medicine" that has only upsides and no downsides isn't medicine, it's diet.
The catch is that there are thousands of promising therapies in animal models/pre-human testing. A very very tiny fraction of them will ever make it to market for a variety of both good and not-good reasons.
Prevalence of the disease - if it only impacts 1/100 million, going to be hard to ever find sufficient patient population to test and recoup your investment.
Existing quality of treatments - if there are already efficacious drugs on the market - how sure are you that this new therapy will be best in class? Only being as good as the status quo is not an ideal competitive position. Conversely, if there is an unmet need because a disease is so lethal/debilitating, regulatory agencies can give latitude in approvals.
Likelihood patient compliance - if it is the most effective drug in the world, but requires intravenous infusion six times a day - nobody is going to adhere to that. GLP drugs are effective, but there is a needle-phobia that is preventing patients getting on board with the idea. Which is why there is an arms race for the first company to develop an oral version.
Toxicity - all chemicals are poisonous. Yet some have a lower therapeutic window than others. If you drug does what it should, but if you take 2x as much and it gives you a heart arrhythmia that is going to be a tough approval for anything but the most deadly conditions.
Yes, you can. The problem with testing is that a candidate treatment may make things worse for patients, not that it may improve things.
If your treatment works, that’s an improvement of what you had before. Once you know that, you can treat all patients. For some, that will be too late, but without your tests, it would be too late for them, too.
If your treatment doesn’t do anything at all, it keeps things the same, but the patients in the test group likely will have had some inconveniences (having to visit a doctor, getting an injection, etc), so you shouldn’t do the test.
If your treatment makes things worse, you of course shouldn’t do the test.
Problem is that you typically only can only know in hindsight which of these applies.
So, you think carefully on whether a treatment could fall in category 3, and, if so, first do it on a group of patients who consent to be Guinea pigs and, often, are already terminally ill, as any negative outcomes will cause less harm to such patients.
Then, as soon as during the test your stats tell the drug does or doesn’t work, you stop the test and either treat all patients or stop treating the test subjects.
I guess I'm not being clear. Are these examples of "good" or "bad" reasons to not go to market? I assume "good"? If so, what would be an example of "bad"? Or vice versa if your meaning was opposite.
I responded below already but since writing that, I've come up with a few more great bad reasons not to bring a drug to market (sorry for the parseability of that one...)
Best bad reason: it would cannibalize an inferior drug currently in your portfolio that's still under patent protection.
I think this behavior is at the far "evil" end of the spectrum of behaviors that drug developers systematically engage in (which I believe is far more banal + less evil than what they're accused of), but it does happen and it's a really nasty
Where it gets especially nasty is when companies buy drugs in development or pre-development from other companies in order to squash (or at least delay) a potentially competitive asset before it reaches the market.
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Another great bad reason, but mostly applies to devices/procedures: the device/procedure is fantastic but for various structural reasons outside of the control of the device/procedure developer, there is insufficient incentive for healthcare providers to actually deploy said device/procedure.
A trivial example would be a pacemaker that requires fewer leads than the competitors and has fewer complications. Great for patients, but potentially totally uninteresting to the electrophysiologists who install it and would get paid less due to the less complex procedure.
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Best good reasons all fall under: making a therapy is unfathomably difficult and most efforts are destined to fail OR (separately) proving a therapy works is unfathomably expensive and most efforts can't produce a positive ROI after that process.
Ultimately most of these decisions come down to economics and not mustache twirling villains. The banality of evil.
Simplest "bad" reasons are the wealth of the patients. Malaria, river blindness, guinea worm, etc are terrible diseases that mostly impact poor people out of sight from Western eyes. Spending $X billion developing a drug for a population that can barely afford to feed themselves is not going to make a financial return on investment.
Well, it would for those countries, but yes, it's not sensible for a private business with no guaranteed source of funding. If they did develop it and no one paid the PR would be even worse.
A lot of potential treatments are too easily available and can't be patented. If a big pharma company can't make massive profit from it, they won't bother bringing it to market. Consider that a not-good reason.
Other treatments may eventually prove to have too many serious negative side effects. That's a good reason to abandon them.
> A lot of potential treatments are too easily available and can't be patented.
This isn’t really an obstacle, at least not as much as it’s made out to be.
There are numerous examples of drugs being brought to market at high prices despite having been generic compounds. Even old drugs can be brought back at $1000/month or more at different doses or delivery mechanisms.
One example: Doxepin is an old antidepressant that is extremely cheap. It was recently re-certified for sleep at lower doses and reintroduced at low doses at a much higher price, despite being “off patent”.
This happens all the time. The drug companies aren’t actually abandoning usable treatments due to patent issues as much as journalists have claimed. If they couldn’t, for some reason, find a way to charge for it they could still use it as a basis for finding an improved relayed compound with more targeted effects, better pharmacokinetics, etc.
They’re not just dropping promising treatments anywhere if there’s a market for them.
Why would a China or India care if it were a viable treatment? Unless a country wants to use their population as lab rats, it takes money and scientists to actually confirm a treatment is safe and effective.
From what I saw, there are very few experimental therapies that claim 100% efficacy, no side effect, no patent on complex engineering process to produce the drug.
I agree with GP that it is very notable.
I mean if it works on humans, which is not a stretch, colorectal cancer is done. It's huge.
Yes there are few that claim 100% efficacy and no side effect at this stage, but there are far, far, far fewer who make it to human availability.
I wouldn't describe it working in humans as "a stretch" per se. I'm not identifying a specific reason it shouldn't work in humans. I'm just saying that's true of thousands and thousands of really great looking treatments (per year!) that, nonetheless, end up not working in humans, or not being convincing enough to even warrant putting them in humans once.
Very small sample size and only in mice. Most experimental treatments don't make it to the clinic, and this could be another in a long list of exciting early results that don't lead to anything.
However...
These results seem too good to be true, but the paper actually seems pretty good. There have been other attempts to use anaerobic bacteria to treat cancer (as solid tumors tend to be hypoxic environments), this is the first I've seen that interacts with PD-1/PD-L1 pathway. This is the most promising cancer treatment I've seen in quite a while.
Maybe we can be cautiously optimistic!
I hesitate to link directly to a single podcast dealer, but if you search for Dave Ricks, CEO of Eli Lilly's podcast with Stripe brothers, there's some alpha in there.
A few years ago we also had 100% effective medication with zero side effects. Now birth rates are down, mortality up, and young people misteriosly die from cancer and hearth attacks.
Interesting article, but in the full paper their key figure (Fig 2) shows their treatment group of n=3 mice completely responded to the bacterial treatment, but their methods say they treated n=5 mice? Could be an honest mistake but that’s a little concerning for data manipulation.
Also agree that using a PD-L1 mab feels like it’s for show especially considering the cancer model they’re using (Colon-26) was shown to be substantially less responsive to PD-L1 inhibitors…
Still the idea is beautiful. Since tumors are oxygen-deficient and suppress the immune response, anaerobic bacteria would proliferate there, and wreak havoc, while in the healthy parts of the organism they would be rapidly eliminated. Additionally, since the bacteria accumulate in the tumor, and the immune system has just responded to their invasion, T-cells will flock to the tumor, destroying what remains of it in due course.
As they say, "the fame of a mathematician is measured by the number of poor papers", because pioneering works are often awkward, treading completely unknown ground. Maybe the same applies to biology sometimes?
Figures 2 and 3 seem to be different experiments, with n=3 and n=5, respectively. Both showed 100% survival. Obviously very small sample sizes, but still promising.
So maybe I am too much a layperson here, but even without any direct therapetutic effects, it is pretty remarkable to have an easily scalable mechanism to get self-replicating agents into tumors, but nowhere else, is it not?
Yes it is amazing! Solid tumors tend to be poorly oxygenated, as they don't have a good network of blood vessels to supply them. The bacteria in these experiments can only live in low oxygen environments, so they will multiply in the tumor and die in any other part of the body they end up in. It's a clever idea, hopefully it will be successful.
Even lay-er person, but maybe the specificity is not that impressive in mice? Perhaps when you scale to more complex animals it is inevitable to see false positives (detrimental effects to healthy cells)?
I have never once seen a promising cancer treatment I've heard of on the news help people. You hear about the breakthrough treatments all the time, but when people get cancer, all you ever hear about is people getting chemotherapy and radiation. Same old scary shit.
Well, I guess Leukemia has been somewhat cured I heard, so that's pretty huge. When I was a kid it was a death sentence IIRC.
I'm not a doctor, but in some fairness, I think there has been a lot of progress in chemotherapy and radiation. "Increasing 5-year-survivability by 0.5%" doesn't make a fun sexy headline, but that's still an achievement that required a lot of hard work and enough of those happening still adds up.
I agree with your overall point though; it's a little annoying that every few weeks we hear about a new experiment that seems to indicate that we'll have a radically new and effective form of treatment for cancer only for it to never materialize.
"Cancer" is a term that covers a lot of diseases. So there is a lot of research going into a lot of different things, and hence lots of announcements.
"Chemotherapy" again is a loaded term covering a lot of different drugs, drug combinations, protocols and so on. So yeah, a lot of cancer treatment us "chemo" - but today's chemo is far removed from 2000 chemo.
5 year survivability has increased tremendously over the last decades. We're not talking 0.5% here, breast cancer for example has gone from 72% to 93%. Early detection of prostrate cancer has near 100% survivability.
But you're right, improving survivability doesn't make for sexy headlines. Yes there's a social media appetite for "breakthroughs", but the underlying "boring" stuff is doing well, and getting better all the time. It's just not "news".
* Many breakthroughs from the first research stages never make it into medical application.
* Many breakthroughs are touted as some kind of "novel treatment", but when they get into the hands of the doctor, they talk about it as chemotherapy, because it kills cancer cells. So you might not even notice that you're getting something novel.
* Many breakthroughs take decades until they actually land in mainstream treatment.
* Many breakthroughs are specific to some kinds of cancer.
That said, in most developed countries, survival rates/times for cancer have been steadily improving for decades.
It's a bit like with solar cell and battery tech breakthroughs: you hear about them all the time, but it takes 20 to 30 years until they make it to production. But both have been improving steadily for an impressively long time.
Yes, you only hear about the initial breakthrough. The regular news doesn't report the trials unless things go spectacularly wrong. And you don't hear about the successes using the therapy on patients where traditional treatments didn't work. And you don't hear about the treatments successful enough that they replace the traditional treatments. But they are there, being used and saving lives. A family member's prostate cancer metastasized after 20 years of hormone therapy, they refused chemotherapy, and had their life saved by radioligand therapy, a treatment not available just months earlier. No side effects beyond a dry mouth, and now off the more debilitating hormone treatments.
Sorry, as someone in this field, this is bullshit. It is in mice.
Several things trigger my bullshit meter. Quote:
"This dramatically surpasses the therapeutic efficacy of current standard treatments, including immune checkpoint inhibitors (anti-PD-L1 antibody) and liposomal doxorubicin (chemotherapy agents)"
PD-L1 monoclonal antibodies are only effective against cancers that are, you guessed it, PD-L1 positive. At high percentages, ranging from 1 to 50%. Are these authors even familiar with the state of the art when it comes to cancer medications? Mouse tumors do not equate to people tumors. Many tumor types are not PD-l1 positive.
Doxy is an ancient SOC chemo.
This is a nothing burger.
Give me phase II/III clinical trials, and then let me know what their PFS/OS was after 5 years. and what the medians were at 3- and 5-years. Also, ORR and CR and needed.
CAR-T is ahead of the game, and will be the ultimate winner here as it grows to scale.
In my dad’s case- he had gastric melonama. We surgically removed it and as consolidation We administered pd-L1 Immune checkpoint inhibitor. Melonama recurred again in 6 months time. This time in esophagus.
As an engineer I think all drugs tested and efficacies studied are on statistically not so significant data points. Given the permutations and combinations far exceed the clinical trials available and hence everything post clinical trial is also just an extended trial.
Wonder How to fix this? I am assuming heLa cells etc are also not the right test setup to have better test results.
Keytruda, pembrolizumab, (what he probably received) can only do so much. If it was in his GI tract it was also elsewhere in multiple places. The PD-L1 drugs at this point have more than 400k patients treated, with decent efficacy. I'm sorry for your loss. If his melanoma had metastasized to his GI tract it was too late for anything except palliative care.
This drug has been used in a huge number of patients for more than 11 years; the next gen of drugs is currently being used. I'm sorry for my curt style of writing, but - people like your father have helped pave the way for that next generation of drugs by constraining clinical trial designs.
Nivumolab was the drug administered in adjuvant setting.
Maybe you are right that 400k patient with decent efficacy - however pegged chances are about 70-80% and not 100. So my point is can there be a better test bench to try and inch closer to a better efficacy?
For example - if hela cells can be used for trials — can there be the cultured tissue be used instead of mice as day 1?
Also curious — how did the scientist decide on using a specific cell/protein to be used for checking if this is producing results. Is it a hunch or science ?
> Sorry, as someone in this field, this is bullshit. It is in mice.
Nice to hear an expert opinion. Let's hope your comment goes back to black. I have a lot of question!
> This is a nothing burger.
Is it enough for a bread-mayo-bread sandwich? Lettuce?
IIUC the bacteria makes the cancer disappear for two weeks, until they end the study and kill the mice. (IIUC this is timeline is usual for very early studies.) They tried other bacterias and one of them made the cancer disappear for a few days, so I'm worried about the long time efficiency of this method.
Is injecting the bacterias a second time as efficient as the first time, or the inmune system kills the bacteria before they hurt the cancer?
What happen in case of metastasis? Each one must be injected with the bacterias or they will jump and make all of them disappear?
Does the bacteria infect other organs and kill you? Is there a good antibiotic in case the bacteria cause problems?
They used cancers that were 200mm3 (i.e. like a sphere of 7mm = 1/4 inch). What happens in bigger cancers? Does bigger cancer have better irrigation and make it more difficult for the bacteria to survive? What happens to tiny hidden metastasis (that probably still have good enough irrigation)?
Seems like a very interesting approach, even if it’s early stage.
> Many tumor types are not PD-l1 positive.
> Doxy is an ancient SOC chemo. This is a nothing burger.
Meh the research didn’t say those were state of the art, but that they were “common” treatments. In other words a baseline for a presumably cheap and well studied animal surrogate.
> CAR-T is ahead of the game, and will be the ultimate winner here as it grows to scale.
Last I read up on it last year CAR-T treatments struggled with solid mass tumors.
Many cancers don’t have unique proteins for CAR-T to target (similar to the pd-l1 issue).
Then CAR-T struggles getting the modified T cells into the solid mass tumors en masse. Interestingly this approach actually makes use of the tumor environment rather than be hindered by it.
Who knows how much knowledge we eradicated due to not bothering with climate change and just letting species go extinct.
Thankfully these were still here for this discovery.
This segment about the mechanism is simple and very profound. I wonder if any cancer researchers here could comment on its universality across various types of cancers:
"Tumor-Specific Accumulation Mechanism
E. americana selectively accumulates in tumor tissues with zero colonization in normal organs. This remarkable tumor specificity arises from multiple synergistic mechanisms:
Hypoxic Environment: The characteristic hypoxia of tumor tissues promotes anaerobic bacterial proliferation
Immunosuppressive Environment: CD47 protein expressed by cancer cells creates local immunosuppression, forming a permissive niche for bacterial survival
Abnormal Vascular Structure: Tumor vessels are leaky, facilitating bacterial extravasation
Metabolic Abnormalities: Tumor-specific metabolites support selective bacterial growth
Excellent Safety Profile
Comprehensive safety evaluation revealed that E. americana demonstrates:
As a rule of thumb, it’s best to assume that all studies like this are in mice or rats unless the headline specifically says “in human trials”.
Murine studies are a dime a dozen and therefore it’s the default assumption when reading research papers. When human trials commence the fact that it’s in humans is a big part of the research and therefore paper titles.
I would be in favor of adding a standardized [in mice] to the titles of all HN submissions about medical breakthroughs. Most of them end up being in mice and many do not reproduce in humans. It would help, at a glance, to know how significant a study's results are.
I know hearing this gets old, however, please review sources outside of LLMs for accuracy. LLMs take a whole bunch off stuff from all over the internet and distill it down to something you can consume. Those sources include everything from reddit to a certain de-wormer that folks still think treats COVID (side note: I've a few long COVID victims in a support group I am in, and they are not happy about the disinfo that was spread, at any rate)...LLMs/"AI" does not and cannot innovate, it can only take all existing information it knows, mash it all together, and present you with a result according to what the model is trained on.
I'm not against AI summaries being on HN, however, users should verify and cite sources so others can verify.
However, I'm just a normal nerd that wants to fact check stuff. Perhaps I'm wrong in wanting to do this. We'll see.
I have significant experience in polymer chemistry, as an experiment, I decided to ask gemini some very specific questions to try and back it into a corner, so to speak. It blew me away with the answer, discussing quite a bit of info I was not even aware of.
> I'm not against AI summaries being on HN, however, users should verify and cite sources so others can verify.
I don't see how they contribute anything to a discussion. Even a speculative comment organically produced is more worthwhile than feeding a slop machine back into itself. I don't go out for coffee to discuss LLM summaries with friends, and I can't imagine why anyone would want to do that here.
Earlier today I asked Gemini Pro to find information on a person's death that was turning up nothing for me otherwise, and it just imagined finding verbatim Obituary quotes in every source, cobbled together vaguely related names, plausible bits and pieces from wherever, almost like it was 2023 again.
It ain't search, and it ain't worthwhile; I'd much rather someone ask an llm the question and then post a question out of curiosity based on it, but without the summary itself
The issue as I see it is just straight copy/pasting its output. You want to use it as a search tool to give you pointers on things to look up and links to read? Great. Then use that as a basis to read the sources and write your own response. If you aren't familiar enough with the subject area to do that, then you also shouldn't be pasting LLM output on it.
Ask it to solve a tough Euler Math puzzle with the search button on and it just copies the answer from the web. Turn search off and it actually computes the answer.
Funny how the search button is taken away though.
Which is "fine" so to speak. We do this with using AIs for coding all the time, don't we? As in, we ask it to do things or tell us things about our code base (which we might be new to as well) but essentially use it as a "search engine+" so to speak. Hopefully it's faster and can provide some sort of understanding faster than we could with searching ourselves and building a mental model while doing it.
But we still need to ask it for and then follow file and line number references (aka "links") and verify it's true and it got the references right and build enough of a mental model ourselves. With code (at least for our code base) it usually does get that right (the references) and I can verify. I might be biased because I both know our code base very well already (but not everything in detail) and I'm a very suspicious person, questioning everything. With humans it sometimes "drives them crazy" but the LLM doesn't mind when I call its BS over and over. I'm always "right" :P
The problem is when you just trust anything it says. I think we need to treat it like a super junior that's trained to very convincingly BS you if it's out of its depth. But it's still great to have said junior do your bidding while you do other things and faster than an actual junior and this junior is available 24/7 (barring any outages ;)).
I've had quite good luck asking Gemini and ChatGPT to include links to research papers for every claim they make. Not only can I review at least the abstracts but I find when I do this, they'll retract some of the hallucinations they've have made in prior messages. It almost seems (and maybe they do) in their web searching tools, reread the content they include. Thus, greatly reducing errors, with minimal extra effort on my part.
> Could it be that this organism switches to anaerobic respiration when it finds itself inside cancer tissue
Unlikely. The leading hypothesis is that mitochondria are a part of the apoptosis cycle, so cells need to disable them to become cancerous. This is called the Warburg effect.
There are several drugs that target this mechanism, inhibiting the anaerobic metabolism. They are effective initially, but cancers always find ways to work around them.
Now I can't wait for the conspiracy theory types to say this proves reptilian people theories. Lizard people just giving to help us accept them type of stuff, and maybe prove how the ape descendants need the lizard people.
I believe parent-poster is making a joke at the expense of conspiracy-theorists who believe in lizard-people, rather than endorsing the idea. To paraphrase, something like:
"This news article links human survival to something taken from amphibians and reptiles. There are conspiracy-theorists who posit the existence of Lizard people. It would be amusing if those humans discovered this news, and claimed it was a plot by Lizard People to make us dependent on them."
So there, I think I explained the joke... which isn't necessarily a good thing. In the words of E.B. White:
> Explaining a joke is like dissecting a frog. You understand it better but the frog dies in the process.
Now, I could work that new amphibian-connection into another joke... But let's face it, it would be "too meta" at this point.
I feel like sometimes the actual act of explaining the joke can actually be funnier than the joke itself. Occasionally when I can explain a super dirty joke with a deadpan and matter-of-fact tone people will laugh more than they would have if they had actually gotten the joke in the first place.
(Disclaimer- I am an engineer and not a microbiologist/doctor)
Mutations and wrong copying of genome happens all the time in the body and some enzyme has the job of correcting the mutated genes so it doesn’t get into the system. Level 2 defence is T cells killing it as identified as foreign body.
Thing that baffles me is that I see most work happening to eliminate tumor. To me it sounds a tough problem given the permutation and combination of mutation— roughly few trillions.
But I was curious if there is working happening on L1 defence — fixing the enzyme that fixes the wrong copy paste mechanism. Or making the enzyme get more efficient and powerful. Is that line of thought even valid?
The immune system is pretty good too, which means any given improvement to the replication system is, all else being equal, probably going to prevent mutations the T cells would already handle. If you need to do the research to figure out what's getting past the immune system anyways, and improving the immune system is lower hanging fruit, it's the logical place to start.
Most cell types have systems to safely manage replication. Broadly, there are gas pedals (oncogenes) and brakes (tumor suppressors). A classic oncogene is something like RAS, which activates a signaling cascacde and stimulates progression through the cell cycle. A canonical tumor suppressor is something like TP53, the most frequently mutated gene in cancer, which senses various cellular stresses and induces apoptosis or senescence.
Most cancer genomes are more complicated than individual point mutations (SNPs), insertions, or deletions. There are copy number alterations, where you have > or < 2 copies of a genomic region or chromosome, large scale genomic rearrangements, metabolism changes, and extrachromosomal DNA. There is a series on the hallmarks of cancer which is a useful overview [1].
All of the mechanisms that intrinsically regulate cell growth would fall under your "L1 defense". Unfortunately, the idea of reversing somatic point mutations is likely to be a challenging approach to treating cancer given the current state of technology.
First, for the reasons above, cancer is often multifactorial and it would be difficult to identify a single driver that would effectively cure the disease if corrected. Second, we don't have currently delivery or in vivo base editing technology that is sensitive or specific enough to cure cancer by this means. There are gene therapies like zolgensma[2] which act to introduce a working episomal (not replacing the damaged version in the genome) copy of the gene responsible for SMA. There are also in vivo cell therapies like CAR T which attempt to introduce a transgene that encodes for an anti-cancer effector on T cells. These sorts of approaches may give some insight into the current state of art in this field.
Edit: also I should note that the genes involved in DNA repair (PARP, BRACA1/2, MSH2, MLH1, etc) are frequently mutated in cancers and therapeutically relevant. There are drugs that target them, sometimes rather successfully (e.g. PARP inhibitors). But the mechanisms of action for these therapies are more complicated than outright correcting the somatic mutations.
1. https://aacrjournals.org/cancerdiscovery/article/12/1/31/675... 2. https://en.wikipedia.org/wiki/Onasemnogene_abeparvovec
You are right. There is a very good explanation in this comic https://phdcomics.com/comics.php?f=1162
But there is much more to it. This is a nice paper for an overview: Hallmarks of Cancer (tng) [0]. It (among others) adds the very important and for years underestimated role of the immune system to the original 2000 paper.
[0] https://www.cell.com/fulltext/S0092-8674(11)00127-9
If we had the tools to easily do that we’d practically be gods.
Also not a doctor or microbiologist, but just wanted to share my layman’s guess on why fixing enzymes will not completely solve the issue: there’s 2 strands of DNA and to fix the broken (mutated) strand you need to have one correct template strand intact so you know what it should be fixed into. It could be the nucleotides swapped places between strands or are deleted completely or otherwise both mutated, which would mean any repair will not revert the sequence to what it used to be.
The other comments so far are probably more informed.
You’d also have to ‘fix’ DNA: unless we can re-engineer a bunch of key enzymes and then re-encode the entire genome (or maybe key parts) with forward error correction without breaking everything else, it might work. You might also break evolution to some degree by making random point mutations less likely.
But what I learned so far is that as soon as you’d attempt something like this in bacteria, the fitness advantage from an evolutionary standpoint is negligible compared to the efficiency loss introduced by FEC, so your colony would get outcompeted by other bacteria unless there is a niche your resistant bacteria survive in (high radiation environments?). The efficiency loss induced ‘disadvantages’ would probably be less pronounced in mammals though - If (big if) you manage to not also break anything essential in the wonderful yet surprisingly efficient Rube Goldberg machine that is life.
Thought experiment, again as a layman, was to see if these genes responsible for error correction at the base level can be fixed or bolstered and that will act like a cancer vaccine. But looks like from other comments that this is even more harder!
Mutations in general are not the defining quality of cancer. It's mutations in these very L1 safeguards. There are several such safeguards and a cell needs several mutations in those to become malignant. Eg. https://en.wikipedia.org/wiki/P53
Correcting genes only works in certain conditions (e.g. limited single strand breaks), in a narrow time frame during cell division, safeguards rather trigger cell suicide, or if that fails they mark the cell for destruction by immune cells. A cell can't fix DNA which made it through cell division once, because it got nothing to proof-read against.
After the safeguards are gone, everything goes and genetic diversity increases quickly within each tumor. This diversity is what's making cancer treatment hard. At some point there won't be a shared vulnerability in all malignant cells. The repair mechanisms are working in favor of the cancer now. For example, with radiation therapy you preferably want to induce DNA double strand breaks, because cancer cells can't repair those. Otherwise you need to increase the radical burden enough to overwhelm repair, but migrating radicals may damage distant cells, too.
I presume you could hypothetically inject mRNA of a working safeguard gene (eg. P53) into all cells (at some point cancer cells can't be selected exclusively, since they lost identifying marks and present as stem cells), so the functional enzyme or transcription factor is forced to be built inside. I am sure people are trying this right now. However, the inner workings of cells on a molecular level are insanely complex and our understanding is only scratching the surface. As with P53, you have a transcription factor, which means it's modifying gene expressions elsewhere. It's only a small part of a complex regulatory cascade. I doubt there is a safeguard target, which can easily be injected without considering the precise timing and environment within that safeguard cascade in the cell. Of course, the rest of the safeguard system needs to be present in the cell to begin with. Mind you, you don't want to cause cell suicide in healthy cells, so you want to restore the function of whole complex.
Then there is the question of delivery. Can you deliver eg. the mRNA to every cell without raising suspicion of the immune system? With the COVID vaccine, the enabling breakthrough was the delivery vehicle, not as much the mRNA part. Can you even reach the cancer cells at all? Cancer cells are frequently cloaked, shadowed or cut of by senescent, or necrotic cells, or acquired unique ways of metabolic adaptations.
Life is complex beyond comprehension! Despite simplifications taught in schools, we actually know sooo little about what's going on in genetics and molecular biology, most medical knowledge is empiric guessing instead of explanatory understanding.
OTOH our L2 isn't that good, mammals in general (with some notable exceptions such as bats, whales and naked mole rats) are prone to cancer in their older age. There probably is a lot of relatively low-hanging fruit there.
If you think about it - individual cells aren't very precious and if some of them gets FUBARed by something (a virus, radiation or chemical insult), it is better to whack it and reuse the proteins to build a new one, if possible, instead of wasting time and resources on reconstruction of a total wreck.
Which also means that some research into replenishment of stem cells is necessary - and this is, IMHO, the really underfunded part of the whole thing. We lose a lot of stem cells as we age. Maybe we don't have to.
If steroids worked, everyone would be constantly injecting them. It would be like drinking coffee.
And that is the reason why steroid injections are harmful. If there is a free lunch, the human body will simply produce the optimal amount of steroids on its own until the Pareto frontier is reached and a tradeoff needs to be made.
Where does the body get the materials to form the steroids? From your diet. So the primary intervention is always a healthy diet and an active lifestyle. You know, the boring things that parents drill into their children.
It's valid but "medicine" that has only upsides and no downsides isn't medicine, it's diet.
This sounds like world changing news. Can anyone with domain expertise explain the catch, if any?
Existing quality of treatments - if there are already efficacious drugs on the market - how sure are you that this new therapy will be best in class? Only being as good as the status quo is not an ideal competitive position. Conversely, if there is an unmet need because a disease is so lethal/debilitating, regulatory agencies can give latitude in approvals.
Likelihood patient compliance - if it is the most effective drug in the world, but requires intravenous infusion six times a day - nobody is going to adhere to that. GLP drugs are effective, but there is a needle-phobia that is preventing patients getting on board with the idea. Which is why there is an arms race for the first company to develop an oral version.
Toxicity - all chemicals are poisonous. Yet some have a lower therapeutic window than others. If you drug does what it should, but if you take 2x as much and it gives you a heart arrhythmia that is going to be a tough approval for anything but the most deadly conditions.
If your treatment works, that’s an improvement of what you had before. Once you know that, you can treat all patients. For some, that will be too late, but without your tests, it would be too late for them, too.
If your treatment doesn’t do anything at all, it keeps things the same, but the patients in the test group likely will have had some inconveniences (having to visit a doctor, getting an injection, etc), so you shouldn’t do the test.
If your treatment makes things worse, you of course shouldn’t do the test.
Problem is that you typically only can only know in hindsight which of these applies.
So, you think carefully on whether a treatment could fall in category 3, and, if so, first do it on a group of patients who consent to be Guinea pigs and, often, are already terminally ill, as any negative outcomes will cause less harm to such patients.
Then, as soon as during the test your stats tell the drug does or doesn’t work, you stop the test and either treat all patients or stop treating the test subjects.
Best bad reason: it would cannibalize an inferior drug currently in your portfolio that's still under patent protection.
I think this behavior is at the far "evil" end of the spectrum of behaviors that drug developers systematically engage in (which I believe is far more banal + less evil than what they're accused of), but it does happen and it's a really nasty
Where it gets especially nasty is when companies buy drugs in development or pre-development from other companies in order to squash (or at least delay) a potentially competitive asset before it reaches the market.
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Another great bad reason, but mostly applies to devices/procedures: the device/procedure is fantastic but for various structural reasons outside of the control of the device/procedure developer, there is insufficient incentive for healthcare providers to actually deploy said device/procedure.
A trivial example would be a pacemaker that requires fewer leads than the competitors and has fewer complications. Great for patients, but potentially totally uninteresting to the electrophysiologists who install it and would get paid less due to the less complex procedure.
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Best good reasons all fall under: making a therapy is unfathomably difficult and most efforts are destined to fail OR (separately) proving a therapy works is unfathomably expensive and most efforts can't produce a positive ROI after that process.
Simplest "bad" reasons are the wealth of the patients. Malaria, river blindness, guinea worm, etc are terrible diseases that mostly impact poor people out of sight from Western eyes. Spending $X billion developing a drug for a population that can barely afford to feed themselves is not going to make a financial return on investment.
* Most drug candidates just don't work
* Even among the drug candidates that do, figuring how to safely deliver them to their target is very hard (looks similar to "just doesn't work")
Bad reasons:
* It's too expensive to prove that a drug works
* It's too difficult to differentiate the patients for whom a drug works and the patients for whom it does not
* It is very hard to predict recruitment and to actually recruit patients for clinical trials
* There aren't enough people with the disorder who are also rich enough to afford treatment to justify development
Other treatments may eventually prove to have too many serious negative side effects. That's a good reason to abandon them.
This isn’t really an obstacle, at least not as much as it’s made out to be.
There are numerous examples of drugs being brought to market at high prices despite having been generic compounds. Even old drugs can be brought back at $1000/month or more at different doses or delivery mechanisms.
One example: Doxepin is an old antidepressant that is extremely cheap. It was recently re-certified for sleep at lower doses and reintroduced at low doses at a much higher price, despite being “off patent”.
This happens all the time. The drug companies aren’t actually abandoning usable treatments due to patent issues as much as journalists have claimed. If they couldn’t, for some reason, find a way to charge for it they could still use it as a basis for finding an improved relayed compound with more targeted effects, better pharmacokinetics, etc.
They’re not just dropping promising treatments anywhere if there’s a market for them.
IIRC it was more about production methods than developing new treatments.
https://fourthievesvinegar.org/
I agree with GP that it is very notable.
I mean if it works on humans, which is not a stretch, colorectal cancer is done. It's huge.
I wouldn't describe it working in humans as "a stretch" per se. I'm not identifying a specific reason it shouldn't work in humans. I'm just saying that's true of thousands and thousands of really great looking treatments (per year!) that, nonetheless, end up not working in humans, or not being convincing enough to even warrant putting them in humans once.
I wonder if anyone has tried to engineer a mouse that lives forever by applying all these life enhancing mouse therapies at once.
Also agree that using a PD-L1 mab feels like it’s for show especially considering the cancer model they’re using (Colon-26) was shown to be substantially less responsive to PD-L1 inhibitors…
Not the world’s best paper imo
As they say, "the fame of a mathematician is measured by the number of poor papers", because pioneering works are often awkward, treading completely unknown ground. Maybe the same applies to biology sometimes?
Crocodile blood antibiotics hope
Scientists are catching crocodiles and sampling their blood in the hope of finding powerful new drugs to fight human infections.
Even horrific fighting wounds on the animal heal quickly
Well, I guess Leukemia has been somewhat cured I heard, so that's pretty huge. When I was a kid it was a death sentence IIRC.
I agree with your overall point though; it's a little annoying that every few weeks we hear about a new experiment that seems to indicate that we'll have a radically new and effective form of treatment for cancer only for it to never materialize.
"Chemotherapy" again is a loaded term covering a lot of different drugs, drug combinations, protocols and so on. So yeah, a lot of cancer treatment us "chemo" - but today's chemo is far removed from 2000 chemo.
5 year survivability has increased tremendously over the last decades. We're not talking 0.5% here, breast cancer for example has gone from 72% to 93%. Early detection of prostrate cancer has near 100% survivability.
But you're right, improving survivability doesn't make for sexy headlines. Yes there's a social media appetite for "breakthroughs", but the underlying "boring" stuff is doing well, and getting better all the time. It's just not "news".
* Many breakthroughs from the first research stages never make it into medical application.
* Many breakthroughs are touted as some kind of "novel treatment", but when they get into the hands of the doctor, they talk about it as chemotherapy, because it kills cancer cells. So you might not even notice that you're getting something novel.
* Many breakthroughs take decades until they actually land in mainstream treatment.
* Many breakthroughs are specific to some kinds of cancer.
That said, in most developed countries, survival rates/times for cancer have been steadily improving for decades.
It's a bit like with solar cell and battery tech breakthroughs: you hear about them all the time, but it takes 20 to 30 years until they make it to production. But both have been improving steadily for an impressively long time.
These are not your parents cancer treatments.
Several things trigger my bullshit meter. Quote:
"This dramatically surpasses the therapeutic efficacy of current standard treatments, including immune checkpoint inhibitors (anti-PD-L1 antibody) and liposomal doxorubicin (chemotherapy agents)"
PD-L1 monoclonal antibodies are only effective against cancers that are, you guessed it, PD-L1 positive. At high percentages, ranging from 1 to 50%. Are these authors even familiar with the state of the art when it comes to cancer medications? Mouse tumors do not equate to people tumors. Many tumor types are not PD-l1 positive.
Doxy is an ancient SOC chemo.
This is a nothing burger.
Give me phase II/III clinical trials, and then let me know what their PFS/OS was after 5 years. and what the medians were at 3- and 5-years. Also, ORR and CR and needed.
CAR-T is ahead of the game, and will be the ultimate winner here as it grows to scale.
As an engineer I think all drugs tested and efficacies studied are on statistically not so significant data points. Given the permutations and combinations far exceed the clinical trials available and hence everything post clinical trial is also just an extended trial.
Wonder How to fix this? I am assuming heLa cells etc are also not the right test setup to have better test results.
This drug has been used in a huge number of patients for more than 11 years; the next gen of drugs is currently being used. I'm sorry for my curt style of writing, but - people like your father have helped pave the way for that next generation of drugs by constraining clinical trial designs.
For example - if hela cells can be used for trials — can there be the cultured tissue be used instead of mice as day 1?
Also curious — how did the scientist decide on using a specific cell/protein to be used for checking if this is producing results. Is it a hunch or science ?
Nice to hear an expert opinion. Let's hope your comment goes back to black. I have a lot of question!
> This is a nothing burger.
Is it enough for a bread-mayo-bread sandwich? Lettuce?
IIUC the bacteria makes the cancer disappear for two weeks, until they end the study and kill the mice. (IIUC this is timeline is usual for very early studies.) They tried other bacterias and one of them made the cancer disappear for a few days, so I'm worried about the long time efficiency of this method.
Is injecting the bacterias a second time as efficient as the first time, or the inmune system kills the bacteria before they hurt the cancer?
What happen in case of metastasis? Each one must be injected with the bacterias or they will jump and make all of them disappear?
Does the bacteria infect other organs and kill you? Is there a good antibiotic in case the bacteria cause problems?
They used cancers that were 200mm3 (i.e. like a sphere of 7mm = 1/4 inch). What happens in bigger cancers? Does bigger cancer have better irrigation and make it more difficult for the bacteria to survive? What happens to tiny hidden metastasis (that probably still have good enough irrigation)?
> Many tumor types are not PD-l1 positive. > Doxy is an ancient SOC chemo. This is a nothing burger.
Meh the research didn’t say those were state of the art, but that they were “common” treatments. In other words a baseline for a presumably cheap and well studied animal surrogate.
> CAR-T is ahead of the game, and will be the ultimate winner here as it grows to scale.
Last I read up on it last year CAR-T treatments struggled with solid mass tumors.
Many cancers don’t have unique proteins for CAR-T to target (similar to the pd-l1 issue).
Then CAR-T struggles getting the modified T cells into the solid mass tumors en masse. Interestingly this approach actually makes use of the tumor environment rather than be hindered by it.
"Tumor-Specific Accumulation Mechanism
E. americana selectively accumulates in tumor tissues with zero colonization in normal organs. This remarkable tumor specificity arises from multiple synergistic mechanisms:
Hypoxic Environment: The characteristic hypoxia of tumor tissues promotes anaerobic bacterial proliferation
Immunosuppressive Environment: CD47 protein expressed by cancer cells creates local immunosuppression, forming a permissive niche for bacterial survival
Abnormal Vascular Structure: Tumor vessels are leaky, facilitating bacterial extravasation
Metabolic Abnormalities: Tumor-specific metabolites support selective bacterial growth
Excellent Safety Profile
Comprehensive safety evaluation revealed that E. americana demonstrates:
Rapid blood clearance (half-life ~1.2 hours, completely undetectable at 24 hours)
Zero bacterial colonization in normal organs including liver, spleen, lung, kidney, and heart
Only transient mild inflammatory responses, normalizing within 72 hours
No chronic toxicity during 60-day extended observation"
Murine studies are a dime a dozen and therefore it’s the default assumption when reading research papers. When human trials commence the fact that it’s in humans is a big part of the research and therefore paper titles.
[0] https://xkcd.com/1217/
Your link is not even about animal studies. It is about a petri dish.
I'm not against AI summaries being on HN, however, users should verify and cite sources so others can verify.
However, I'm just a normal nerd that wants to fact check stuff. Perhaps I'm wrong in wanting to do this. We'll see.
I don't see how they contribute anything to a discussion. Even a speculative comment organically produced is more worthwhile than feeding a slop machine back into itself. I don't go out for coffee to discuss LLM summaries with friends, and I can't imagine why anyone would want to do that here.
Earlier today I asked Gemini Pro to find information on a person's death that was turning up nothing for me otherwise, and it just imagined finding verbatim Obituary quotes in every source, cobbled together vaguely related names, plausible bits and pieces from wherever, almost like it was 2023 again.
It ain't search, and it ain't worthwhile; I'd much rather someone ask an llm the question and then post a question out of curiosity based on it, but without the summary itself
It does well at filtering information for you.
Going to primary sources is required to verify what it says but it can reduce the leg work rather a lot.
Unfortunately it can hallucinate those too. I've had ChatGPT cite countless nonexistent academic papers, complete with links that go nowhere.
But we still need to ask it for and then follow file and line number references (aka "links") and verify it's true and it got the references right and build enough of a mental model ourselves. With code (at least for our code base) it usually does get that right (the references) and I can verify. I might be biased because I both know our code base very well already (but not everything in detail) and I'm a very suspicious person, questioning everything. With humans it sometimes "drives them crazy" but the LLM doesn't mind when I call its BS over and over. I'm always "right" :P
The problem is when you just trust anything it says. I think we need to treat it like a super junior that's trained to very convincingly BS you if it's out of its depth. But it's still great to have said junior do your bidding while you do other things and faster than an actual junior and this junior is available 24/7 (barring any outages ;)).
Unlikely. The leading hypothesis is that mitochondria are a part of the apoptosis cycle, so cells need to disable them to become cancerous. This is called the Warburg effect.
There are several drugs that target this mechanism, inhibiting the anaerobic metabolism. They are effective initially, but cancers always find ways to work around them.
"This news article links human survival to something taken from amphibians and reptiles. There are conspiracy-theorists who posit the existence of Lizard people. It would be amusing if those humans discovered this news, and claimed it was a plot by Lizard People to make us dependent on them."
So there, I think I explained the joke... which isn't necessarily a good thing. In the words of E.B. White:
> Explaining a joke is like dissecting a frog. You understand it better but the frog dies in the process.
Now, I could work that new amphibian-connection into another joke... But let's face it, it would be "too meta" at this point.