Altered Immune Cells Help Girl Beat Leukemia 130
An anonymous reader writes "For decades, one of cancer's most powerful weapons has been to corrupt the human immune system. Finally, researchers in Philadelphia have developed a way to turn that weapon against certain cancers, and potentially open the door to a whole new generation of therapies for all manner of cancers. From the article: 'It is hard to believe, but last spring Emma, then 6, was near death from leukemia. She had relapsed twice after chemotherapy, and doctors had run out of options. Desperate to save her, her parents sought an experimental treatment at the Children’s Hospital of Philadelphia, one that had never before been tried in a child, or in anyone with the type of leukemia Emma had. The experiment, in April, used a disabled form of the virus that causes AIDS to reprogram Emma’s immune system genetically to kill cancer cells.'"
Balancing potential deaths with real-today ones (Score:2, Interesting)
Really; it sounds wonderful, but if Murphy and Pandora had a child, his/her favorite toy would be using lethal viruses to help us combat lethal cancers.
Using nuclear weapons to plug oil gushers, using attack polar bears to guard your bunny farm, using a scalpel to pick your nose... these ideas will go right some of the time too.
A link with more detail:
http://www.telegraph.co.uk/health/healthnews/9508895/A-virus-that-kills-cancer-the-cure-thats-waiting-in-the-coldc.html [telegraph.co.uk]
AIDS vs. Cancer (Score:2, Interesting)
If it turns out that the AIDS virus took 50 years off of the timeline to finding a cure for cancer, I wonder if the AIDS epidemic was worth it.
Re:Balancing potential deaths with real-today ones (Score:5, Interesting)
Your link isn't the same research as what the article is talking about though.
The article is about removing a patient's stem cells, using neutered HIV to deliver a payload to them that changes the immune system at a genetic level and then reintroducing the stem cells into the patient. The patient's immune system would then be equipped to kill the cancer. Your link discusses infecting patients with a virus that targets cancer cells preferentially, killing a cancer while at the same time giving the patient only mild symptoms.
On the one had, the article is talking about real, honest to goodness genetic engineering of a living human being which is, quite frankly, science fiction levels of amazing. But it almost universally causes a cytokinetic swarm in the patient as the immune system suddenly knows how to fight massive amounts of what it suddenly sees as infected tissue (actually tumors). The HIV is disabled the same way other viruses are disabled to create vaccines, and even if the patient got HIV somehow that would in fact still be preferable than dying immediately from cancer.
On the other, your article would indicate a cure that would be essentially zero cost to produce. The side affects are minimal but, and this is the proverbial "but" that is probably killing all research on the topic, you also have a virus that is capable of killing the vast majority of one tissue type (tumor) inside the human body. And that is quite frankly terrifying. Until you can quantify how likely or unlikely the virus is to target a different tissue type and how likely is it that the virus is communicable (or could mutate to become so) you won't be trying it out on anyone.
Re:Let's all be honest... (Score:5, Interesting)
While there are problems with the GP's theory, you may not completely be understanding capitalism yourself, at least as it seems to apply to the pharmaceutical industry. For example, there have been many instances of sweetheart deals between drug manufacturers with expiring patents and manufacturers of generics where the original manufacturer has paid the generic manufacturers _not_ to produce generics. As long as the profit margin is high enough on the original and would be low enough on the generics, it's viable. At least, it's viable enough for long enough that, even if you can't say that the industry outright blocks things, it does have a certain... inertia about it.
My mother almost had a similar treatment (Score:5, Interesting)
My mother was diagnosed with acute myelodysplastic syndrome in 2006, and the doctors she spoke with talked about this type of treatment. At the time it was not ready for use in humans, however. We did talk for awhile with the doctors about the nature of cancer and this type of treatment.
Many people are aware that cancer is present in almost all people at several times in their lives. The vast majority of cancers are from genetic defects that the body detects as an alien, and it will attack and destroy the mutated cells just as foreign bacteria or a transplanted organ are. Now, the types of cancer that we talk about and that result in terminal illness is from a mutation that is different enough to be deadly and parasitic to the human body, but not different enough to be detected as different.
All cells contain markers that act as identification badges. Last I was aware, there were 10 known genetic markers for humans that determine this identity (only six were known in the 1990's, so this is pretty new stuff). Its these markers that are used to find organ and tissue donors. However, even a perfect 10 out of 10 match is not enough to guarantee that foreign tissue will be detected as alien, so we know that our known list of 10 markers is incomplete. This is why perfect matches still face rejection risks.
The problem then, from a leukemia perspective, is that donor bone marrow will produce white blood cells that see the recipient body as alien, and attack it. That's kind of what you want, since the idea is to kill the cancerous bone marrow, but it's not exactly discriminate about what it will attack. So for leukemia treatment, you don't even want a perfect 10 out of 10 match since that would be counterproductive. Perfect donor bone marrow wouldn't identify the cancer either, and the cancer would relapse.
What this treatment does is gives doctors a way to tell your body that certain cells are aliens by forcefully altering their DNA. Then the body can just fix itself. That's really what medicine does best: allows the body time to fix itself.
"How can this possibly work?" you think. "Aren't all cancers different?" Well, it turns out the answer is "sort of". We categorize cancers based on the kind of tissue that is affected, but that's really not accurate. We should categorize it based on exactly what genetic sequence mutated and in exactly what way. Cancer, then, is literally a family of thousands of diseases with very similar symptoms. Many cancer types are, in fact, mutations of the same segment in the same way. However, now that we are able to sequence the DNA of a human, we ought to be able to accurately categorize each person's individual cancer by sequencing healthy and cancerous cells. We can then design a DNA segment which will only work in the DNA sequence of cancerous cells and that will identify the cells as alien to the body. The body will then attack the cancer, and destroy it. We will, literally, paint a target on the cancer cells for the human body to destroy. The mechanism for delivery of this kind of genetic manipulation is already supplied to us by nature in the form of a retrovirus. In this girl's case, the retrovirus that seeks out her cancerous cell type is HIV, which attacks white blood cells.
This, then, is the most promising path to the cure for cancer. It will not be cured with a single treatment like polio or smallpox, but the method can be applied over and over against every type of cancer.
My mother was given more traditional treatment with a bone marrow transplant. The best match that could be identified was an 8 out of 10 match. Even so she successfully underwent the transplant and survived a year longer than she was given when diagnosed. She then relapsed, and was beginning her second treatment when she died from a massive stroke caused by all the medications required to treat the disease and the anti-rejection drugs and the side effects of the medications. If she had had this kind of option where doctors could reprogram her immune system to seek and destroy the cancerous bone marrow like it's supposed to instead of having to rely on grafted bone marrow that would attack her healthy tissue as well, she might still be alive today.
Re:My mother almost had a similar treatment (Score:3, Interesting)
So for leukemia treatment, you don't even want a perfect 10 out of 10 match since that would be counterproductive. Perfect donor bone marrow wouldn't identify the cancer either, and the cancer would relapse.
Actually, that's not automatically true.
My youngest son developed Acute Myelogenous Leukemia when he was 18 months. He underwent chemo for six months and went into remission. Eight months later he relapsed, so the doctors told us that the next step was a bone marrow transplant. To have peace of mind that we were doing all we could to save him, my wife insisted that she and I get tested for donor compatibility even though the odds of a parent being an acceptable donor are infinitesimal. The donor and patient must match on seven of those ten DNA alleles to be a viable match and since a child only gets 50% of his/her DNA from either parent, the chance of matching on seven points is very small. The best chances for matches come from siblings and any one sibling only has a 25% of matching. Our son and his brother weren't an acceptable match so the doctors started a search through the National Bone Marrow registry.
Until my wife came back as a ten-point match.
The doctors swore that they must have sent in two vials of my son's blood for testing on accident and insisted on a re-test. She came back a ten-point match again. Blew everyone's mind. It turns out that my wife and I share 5 of those critical DNA alleles and those are the five that I gave to our son. He got the other five that my wife and I don't share from her. The odds against that happening are astronomical. Somewhere in the ancient dim past, a common ancestor sent his/her DNA out into the world and somehow, despite generations of separation, those 5 alleles manifested in both me and my wife. We checked the genealogy and can't find any ancestor closer than one who came over on the Mayflower in the 17th century. So we're talking something like 20 generations of separation minimum.
Think of it this way--at 20 generations of separation, my wife would only share those five alleles with one man in a million. Imagine that she walked into a stadium full of a million potential mates tied to that common ancestor, and still manages to pick me out of the crowd. Then, the odds of me giving our those five alleles that my wife and I share and her matching him on the other five are 250,000:1. After picking me out of a crowd of a million men, my wife and I would then have to have 250,000 children to guarantee one would manifest those ten alleles. We would have a far better chance of winning the Powerball lottery.
Long story short--she was the donor. My son has been leukemia-free for three years now and the doctors have no expectation that it will recur. He suffers from minor graft-vs-host disease and has to take cyclosporin to keep his immune system from attacking his own body--so, yes, there are clearly some other clearly critical but as yet unidentified alleles they don't share--but he is otherwise normal. And here's the kicker. Because my wife's immune system is now his immune system, the doctors tell us that she could donate him an organ and he would suffer no rejection issues because his immune system would recognize her tissue as being native and accept it.
Genetics is a freaking cool science.