One Drug to Shrink All Tumors • Hacker News Board

Re: One Drug to Shrink All Tumors

#41

Post by Udo » Tue, Mar 27, 2012, 1:24 PM UTC

jballanc wrote: post #37

Udo wrote: post #32

Earlier quoted context omitted.

Yes, however, the "drug" described (it's more of an idea for a drug at this stage, really) does not aim to disrupt the tumor cell itself. Instead it's based on the observation that many (maybe most?) cancerous cells over-express the protein CD47 on their surfaces as a survival mechanism in order to prevent macrophages and dendrites from taking them out. If successful - and that's a big if, because I'd be willing to w…

Unfortunately, evolution is evolution, and if there is any way that cancer cells can trick the immune system that does not require CD47, trust me we'll know about it after the first few months using this drug. We've probably learned more about the intricate inner workings of cells by studying the ways in which cancers can evade treatments than by any other method. Still, I don't doubt this will be another tool in the…

  Unfortunately, evolution is evolution, and if there is any way that 
  cancer cells can trick the immune system that does not require CD47, 
  trust me we'll know about it after the first few months using this drug.

I totally agree. Also, I'm skeptical about side effects. We'll see. As I said, I don't believe this will come out as an actual drug.

  What I find mildly disappointing is that cancer is an evolutionary 
  process, but it is still treated primarily as a cell signaling disease.

Absolutely. We spend a lot of time figuring out the biochemical intricacies of very specialized tumor cells with, predictably, not a lot to show for it. My guess is we'll be making inroads this way as far as pre-cancerous and early stage disease is concerned but we simply lack the technology to deal with the phenomenon itself. To speculate further, I don't think this will be solved by micro-advancements in pharmaceuticals (even quite well-targeted ones), I believe we need a new class of active agent that can go in there and make decisions on a cell-by-cell basis if necessary.

Re: One Drug to Shrink All Tumors

#42

Post by Symmetry » Tue, Mar 27, 2012, 1:29 PM UTC

bedris wrote: post #39

antihero wrote: post #26

Earlier quoted context omitted.

Isn't this marker also used by healthy cells? So what is to stop your system basically attacking itself massively?

Good question. I'm an author on both of the new CD47 studies, so I'll try to answer this for you: 1. CD47 appears to be higher on tumor cells than on normal cells. In general, the higher the expression of a marker on a diseased cell versus a healthy cell, the more of a therapeutic window/index [1] that is available for a treatment to specifically target diseased cells. 2. Inhibiting the anti-phagocytosis (i.e., "don'…

It does sound like a very promising avenue, but I imagine that this route could still be a problem for people already pre-disposed to autoimmune diseases. Still, most of those aren't as bad as the alternative here. Any drug based on this doesn't have to not have side effects, it just has to be better than normal chemotherapy.

Re: One Drug to Shrink All Tumors

#43

Post by weavejester » Tue, Mar 27, 2012, 1:35 PM UTC

jballanc wrote: post #37

Udo wrote: post #32

Earlier quoted context omitted.

Yes, however, the "drug" described (it's more of an idea for a drug at this stage, really) does not aim to disrupt the tumor cell itself. Instead it's based on the observation that many (maybe most?) cancerous cells over-express the protein CD47 on their surfaces as a survival mechanism in order to prevent macrophages and dendrites from taking them out. If successful - and that's a big if, because I'd be willing to w…

Unfortunately, evolution is evolution, and if there is any way that cancer cells can trick the immune system that does not require CD47, trust me we'll know about it after the first few months using this drug. We've probably learned more about the intricate inner workings of cells by studying the ways in which cancers can evade treatments than by any other method. Still, I don't doubt this will be another tool in the…

Isn't the evolution of cancer cells rather more constrained than your average pathogen? A normal pathogen can infect many thousands or millions of hosts, and can evolve immunities over many years, decades or centuries. A cancer is limited to a single host, and cannot pass on any of its tricks; it must start from scratch each time.

If we had medicine as potent as penicillin that could attack or inhibit certain cancer cells, it might be that the cancer simply wouldn't have the time to fight back before it's removed entirely.

Cancer cells are rather more difficult to distinguish from normal cells than bacteria, of course, but it seems reasonable to assume we'd have less problems with cancer cells evolving defences.

Re: One Drug to Shrink All Tumors

#44

Post by pja » Tue, Mar 27, 2012, 2:18 PM UTC

tomkin wrote: post #38

pja wrote: post #35

Earlier quoted context omitted.

You read many articles like this because the press likes to latch onto every research finding and shout "Drug X / Prof Y cures cancer!" In reality, cancer is many, many different diseases. About the only thing that cancers share is the property of uncontrolled (and unwanted) growth. Some of these cancers we already know how to cure, others remain incurable to date. The reality is probably that there is no "cure for c…

I used to think that, until I watched the TED talk by William Li [1]. The process of angiogenesis can be found as the catalyst in every cancer and medicine/food already work to reverse or halt angiogenesis. Doxycycline, for example, is a broad-spectrum anti-biotic that has been around for decades, is cheap and readily available and has been successful at slowing or regressing tumors. [2] [1] http://www.ted.com/talks/…

Silver bullets usually aren't. (Sadly.)

Yeah, these drugs appear to improve survival times somewhat, but at extortionate expense.

Avastin for instance has been something of a disappointment: yes, it appears to delay mortality but that's about it & the FDA has pulled its approval for use in breast cancer because there was no evidence that it actually helped. The side effects can also be difficult, as you might expect for a drug that targets a process like blood vessel growth.

If dietary changes could have profound effects on cancer progression then a controlled trial would be simple (and ethically straightforward). In reality, eating a decent diet is known to reduce the rates of cancer & improve survival rates of those who are diagnosed with cancer, but it isn't a cure & it probably never will be.

Re: One Drug to Shrink All Tumors

#45

Post by refurb » Tue, Mar 27, 2012, 2:30 PM UTC

weavejester wrote: post #43

jballanc wrote: post #37

Earlier quoted context omitted.

Unfortunately, evolution is evolution, and if there is any way that cancer cells can trick the immune system that does not require CD47, trust me we'll know about it after the first few months using this drug. We've probably learned more about the intricate inner workings of cells by studying the ways in which cancers can evade treatments than by any other method. Still, I don't doubt this will be another tool in the…

Isn't the evolution of cancer cells rather more constrained than your average pathogen? A normal pathogen can infect many thousands or millions of hosts, and can evolve immunities over many years, decades or centuries. A cancer is limited to a single host, and cannot pass on any of its tricks; it must start from scratch each time. If we had medicine as potent as penicillin that could attack or inhibit certain cancer…

One big difference between typical pathogens and cancer cells is that cancer cells have much more unstable genomes. Cancer cells divide rapidly and when they do, all sorts of mutations occur.

Even for someone with a diagnosed cancer (i.e. ovarian cancer), there are typically hundreds if not thousands of different types of cancer cells. This is what makes treating cancer so difficult. A drug may knock down 95% of your cancer, but the cells it didn't kill have no problem coming back and are now treatment-resistant.

Re: One Drug to Shrink All Tumors

#46

Post by refurb » Tue, Mar 27, 2012, 2:32 PM UTC

Daniel_Newby wrote: post #28

fasteddie31003 wrote: post #5

Here is my take on curing cancer from a programmers perspective. Extract a healthy strain of DNA from the patient, insert the healthy DNA into a virus that will be targeted to attack all cells of a certain type, which will include the cancerous cells. The erroneous/ cancerous will be replaced with the healthy DNA, while healthy cells get the DNA they already had. It's kinda like reformatting a hard drive. Has anyone…

> ... a virus that will be targeted to attack all cells of a certain type ... The trouble is that living things are basically made of fancy Jello. There is no programmable interface to say "go here".

Actually, look up a company called Oncolytics. It's based around a technology that you can create viruses that only infect cancer cells. There is a lot of work going on in this area.

Re: One Drug to Shrink All Tumors

#47

Post by onemoreact » Tue, Mar 27, 2012, 2:32 PM UTC

weavejester wrote: post #43

jballanc wrote: post #37

Earlier quoted context omitted.

Unfortunately, evolution is evolution, and if there is any way that cancer cells can trick the immune system that does not require CD47, trust me we'll know about it after the first few months using this drug. We've probably learned more about the intricate inner workings of cells by studying the ways in which cancers can evade treatments than by any other method. Still, I don't doubt this will be another tool in the…

Isn't the evolution of cancer cells rather more constrained than your average pathogen? A normal pathogen can infect many thousands or millions of hosts, and can evolve immunities over many years, decades or centuries. A cancer is limited to a single host, and cannot pass on any of its tricks; it must start from scratch each time. If we had medicine as potent as penicillin that could attack or inhibit certain cancer…

There are plenty of drugs that work for cancer type A, B, C etc. Unfortunately, there are billions of people in the world all randomly generating Cancer's so all possible mutations are going to show up eventually in somebody.

Which presents the problem, let's say the most common 50% of all cancers are easily cured by drug X. Well the other 50% are all less common and moving to 100% is only going to get harder as you progress.

Re: One Drug to Shrink All Tumors

#48

Post by mikecane » Tue, Mar 27, 2012, 2:57 PM UTC

onemoreact wrote: post #47

weavejester wrote: post #43

Earlier quoted context omitted.

Isn't the evolution of cancer cells rather more constrained than your average pathogen? A normal pathogen can infect many thousands or millions of hosts, and can evolve immunities over many years, decades or centuries. A cancer is limited to a single host, and cannot pass on any of its tricks; it must start from scratch each time. If we had medicine as potent as penicillin that could attack or inhibit certain cancer…

There are plenty of drugs that work for cancer type A, B, C etc. Unfortunately, there are billions of people in the world all randomly generating Cancer's so all possible mutations are going to show up eventually in somebody. Which presents the problem, let's say the most common 50% of all cancers are easily cured by drug X. Well the other 50% are all less common and moving to 100% is only going to get harder as you…

>>>Which presents the problem, let's say the most common 50% of all cancers are easily cured by drug X. Well the other 50% are all less common and moving to 100% is only going to get harder as you progress.

But for those who are in the 50% who can be cured in the first wave...

... and maybe one of them will go on to develop the cure that helps the remaining 50%.

Re: One Drug to Shrink All Tumors

#49

Post by bedris » Tue, Mar 27, 2012, 3:07 PM UTC

Symmetry wrote: post #42

bedris wrote: post #39

Earlier quoted context omitted.

Good question. I'm an author on both of the new CD47 studies, so I'll try to answer this for you: 1. CD47 appears to be higher on tumor cells than on normal cells. In general, the higher the expression of a marker on a diseased cell versus a healthy cell, the more of a therapeutic window/index [1] that is available for a treatment to specifically target diseased cells. 2. Inhibiting the anti-phagocytosis (i.e., "don'…

It does sound like a very promising avenue, but I imagine that this route could still be a problem for people already pre-disposed to autoimmune diseases. Still, most of those aren't as bad as the alternative here. Any drug based on this doesn't have to not have side effects, it just has to be better than normal chemotherapy.

You raise another good point here, that the allowable side effect profiles for cancer drugs are much less stringent than for drugs indicated for less life-threatening diseases.

Re: One Drug to Shrink All Tumors

#50

Post by tomkin » Tue, Mar 27, 2012, 4:14 PM UTC

pja wrote: post #44

tomkin wrote: post #38

Earlier quoted context omitted.

I used to think that, until I watched the TED talk by William Li [1]. The process of angiogenesis can be found as the catalyst in every cancer and medicine/food already work to reverse or halt angiogenesis. Doxycycline, for example, is a broad-spectrum anti-biotic that has been around for decades, is cheap and readily available and has been successful at slowing or regressing tumors. [2] [1] http://www.ted.com/talks/…

Silver bullets usually aren't. (Sadly.) Yeah, these drugs appear to improve survival times somewhat, but at extortionate expense. Avastin for instance has been something of a disappointment: yes, it appears to delay mortality but that's about it & the FDA has pulled its approval for use in breast cancer because there was no evidence that it actually helped. The side effects can also be difficult, as you might expect…

There's a lot to be said for getting to the cancer before it takes off. Silver bullets are easy to dismiss, but what we're really talking about is stopping a simple process with a simple process. It would be hard to stop a missile once it's off the ground, but from the silo it's a matter of turning off a few switches - or rather, not allowing them to be turned on.

I don't claim to know medicine, but I am familiar with simple measures equating to great results when acting on initial factors. An ounce of prevention equals a pound of cure in this case.