![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
One of the things I like about being a grad student at a prestigious research university is that there are cool seminars happening all the time. Today, I went to one about the use of antibodies to target-deliver cancer drugs.
The idea for the targeting part is fairly simple. Cancer cells, due to their tendency to fail when it comes to copying DNA with high precision, have messed-up DNA. It gets progressively more messed up as they go along. As a result, they produce in addition to normal proteins which are required to live some pretty messed-up proteins. All cells have some proteins that show up on the cell surface, so of course cancer cells have them too. When a messed-up protein is on the cell surface, it can be used as a target for an antibody. The antibody will entirely ignore healthy cells that don't display the mutant protein.
To the end of the antibody that doesn't bind the target, they have attached a drug. The drug is linked very specifically, such that it will be "digested" off of the antibody once the cell ingests it. (Truefax: the cells can recognize a bound antibody, and sometimes will try to eat it so they can free their protein up to do whatever it was doing.) This releases the drug, although only into the lysosome in the cell. But it is really cool, because while it was bound to the antibody it was inactive. Now that it has been released, it is active.
The drug is a derivative of a toxin they found in sea hares, which are apparently an animal that produces deadly toxins. Because the only place in the body that you will ever find the active toxin is inside the cancer cells, you don't have to pump the patient full of poison and hope it kills the cancer cells faster than all the other ones. Truefax: that is how chemo "works." Instead, you give them doses of antibody-drug that are pretty much a small shot every three weeks. The antibodies home in on the cancer like little cancer-seeking missiles and deliver their payload. By some magic, the drug then escapes the lysosome and kills the cell. Yey! ^_^
(We think that in fact what it does is make a hole in the lysosome. A lysosome is like a tiny little stomach, with high acid and enzymes whose sole purpose is to attack and degrade other enzymes. Releasing them into the cell is usually a bad thing. Usually.)
The presenter was like the academic's academic, slightly awkward about presenting to a room full of interested people, but so excited about what he was doing that he soon forgot it. And it was very interesting. In the clinical trial, a whopping ninety-six percent of patients went into complete remission after only eight of a potential sixteen doses, and stayed there for on average two years. Out of those, another fifty percent went straight back into remission when given the exact same treatment. This is in an industry where a sixty to seventy percent response is considered fantastic, and he did this for a previously untreatable cancer. By which I mean, if you were diagnosed and didn't respond to chemo within weeks you had less than a year to live. And this is the first treatment this guy has produced! I mean, can you imagine what he's going to do?
In short, I love this place!
The idea for the targeting part is fairly simple. Cancer cells, due to their tendency to fail when it comes to copying DNA with high precision, have messed-up DNA. It gets progressively more messed up as they go along. As a result, they produce in addition to normal proteins which are required to live some pretty messed-up proteins. All cells have some proteins that show up on the cell surface, so of course cancer cells have them too. When a messed-up protein is on the cell surface, it can be used as a target for an antibody. The antibody will entirely ignore healthy cells that don't display the mutant protein.
To the end of the antibody that doesn't bind the target, they have attached a drug. The drug is linked very specifically, such that it will be "digested" off of the antibody once the cell ingests it. (Truefax: the cells can recognize a bound antibody, and sometimes will try to eat it so they can free their protein up to do whatever it was doing.) This releases the drug, although only into the lysosome in the cell. But it is really cool, because while it was bound to the antibody it was inactive. Now that it has been released, it is active.
The drug is a derivative of a toxin they found in sea hares, which are apparently an animal that produces deadly toxins. Because the only place in the body that you will ever find the active toxin is inside the cancer cells, you don't have to pump the patient full of poison and hope it kills the cancer cells faster than all the other ones. Truefax: that is how chemo "works." Instead, you give them doses of antibody-drug that are pretty much a small shot every three weeks. The antibodies home in on the cancer like little cancer-seeking missiles and deliver their payload. By some magic, the drug then escapes the lysosome and kills the cell. Yey! ^_^
(We think that in fact what it does is make a hole in the lysosome. A lysosome is like a tiny little stomach, with high acid and enzymes whose sole purpose is to attack and degrade other enzymes. Releasing them into the cell is usually a bad thing. Usually.)
The presenter was like the academic's academic, slightly awkward about presenting to a room full of interested people, but so excited about what he was doing that he soon forgot it. And it was very interesting. In the clinical trial, a whopping ninety-six percent of patients went into complete remission after only eight of a potential sixteen doses, and stayed there for on average two years. Out of those, another fifty percent went straight back into remission when given the exact same treatment. This is in an industry where a sixty to seventy percent response is considered fantastic, and he did this for a previously untreatable cancer. By which I mean, if you were diagnosed and didn't respond to chemo within weeks you had less than a year to live. And this is the first treatment this guy has produced! I mean, can you imagine what he's going to do?
In short, I love this place!
