England, probably 2008. Pub grub
I’m working at Fred Hutch today (3/22/12) and have just finished filing several cases of surgical records. I hope all of the surgical outcomes were positive, but I’m afraid that’s unlikely.
Earlier I spent some quality time reading this week’s NCI Cancer Bulletin. There were several items of interest; right now, I want to comment on one, about pancreatic cancer. I believe that was the type of cancer that Steve Jobs suffered from, but I may be wrong.
The article states that pancreatic cancer is notoriously resistant to chemo and radiation therapy: apparently the 5-year survival rate is less than 5%. Part of the reason for this dismal prognosis is that, as a pancreatic tumor grows, it provides itself with a thick “matrix” (protective layer?) that exerts a powerful pressure on the tumor, sufficient to actually flatten the blood vessels within it. Without blood vessels to act as a delivery system the tumor just goes its merry way – unfortunately.
There does appear to be hope just over the horizon, however. Scientists here at the Hutch have found (studying our friend, the mouse) that an enzyme (PEGPH20 , if you must know) chops up a molecule forming part of the matrix, thereby relieving the pressure and allowing chemo to flood in, and save the mouse . Too bad that wasn’t available for Jobs. He was a creative, useful guy; who knows how many more clever but expensive gadgets we would have absolutely needed if he had lived!
So, I ask myself, why does that tumor secrete that matrix? Years ago I read a very interesting book by Peter Dawkins titled “The Selfish Gene”. Dawkins is a famous English biologist, specializing in evolutionary theory. His thesis in this book boils down to the gene being the fundamental “unit” of evolution; that is, evolutionary processes work so as to allow the genes for adaptive traits to survive and multiply. So, if Dawkins is right, why does this damned tumor act in such a way as to kill the thing that contains it? It is as if the tumor genome is protecting itself, much as (says Dawkins) the genome of the individual behaves to advance the whole organism? Cancer cells are not attacked by our immune system because they are part of “us”; just wildly reproducing “normal” cells. However, naively, it seems to me that the pancreatic cancer cell knows it isn’t welcome, and prepares that matrix for self defense. More than likely I’m way off base, and the matrix has some other explanation. However, if we could ever persuade our immune system that cancer cells aren’t “us”, what a better world would result!
You are stimulating my science gene, that you know is in the Joyce/Schneider make-up. I appreciate your explanations. Also, putting "Not OC" on some blog posts is a good plan for those that will come here for one or the other blog entries. Keep this up, Myrl!
ReplyDeleteThis is thought-provoking. Some things in genetics are just accidents with no real purpose. But I would also like to know more about the matrix. I think of a matrix as a scaffold, not sure if that's what they mean though. I have never thought of cancer in evolutionary terms before, but I suppose you could argue that the cancer cells are more fit than your noncancerous cells, until, of course, they kill their host.
ReplyDeleteSo I THINK I am finally signed up to comment on the blogs. I'm about to find out! I've enjoyed them a lot and think you should keep doing it. It takes a while to build a following so don't quit yet!
I wrote a "reply", but my computer ate it. The gist: I think you're right.
ReplyDeleteI did more research on this item, and found the following:
ReplyDelete1) The “matrix” referred to in the NCI article describing this research really is “extracellular”. I visualize it as spreading between adjacent cancer cells, squeezing them flat and preventing the entry of chemo drugs.
2) The matrix is composed of fibroblasts (whatever that means), immune cells, epithelial cells, and something called hyaluronic acid.
3) Using an enzyme (PEGPH20) in combination with a chemo drug it was possible to “get at” the cancer cells (in, of course, our little furry friend, the mouse.)
4) This resulted in a 70% increase in overall survival of our little friends.
You can read a tolerably penetrable account of this research on the Fred Hutch web site.
Depressing reality: (1) the 5-year survival rate of humans with this type of pancreatic cancer is 5%; (2) This potential treatment merely increases survival rate – it’s not a cure.
But, anyway – keep up the good work!
Owing to the sharp-eyed scrutiny of my chief editor, Richard Ingwall, I need to inform my many readers that it was RICHARD (not Peter) Dawkins who wrote "The Selfish Gene". Thanks, Peter.
ReplyDeleteMyrl