Tuesday, March 27, 2012
A cure for most cancers?
It has been known for a while that cancer cells produce a higher level of a protein called CD47. That same protein is found in healthy cells, though not in as high levels. CD47 is a marker that tells our bodies' immune system not to destroy them. The cancer cells use this marker to avoid being destroyed by the immune system. In fact, how much of a higher level one has of CD47 is a fairly good predictor of mortality: since cancer cells have CD47 at higher levels than healthy cells, the higher the level of that protein, the more likely the patient will die. So this bright biologist at Stanford developed an antibody that blocked CD47. He first gave it to mice with blood cancers. Lo and behold, their immune system recognized the cancer cells as invaders and a number of the mice were cured when their own immune systems killed the cancer cells. But the story gets better. A number of human cancer tissues from many types of cancers were transplanted into mice. The control rodents largely died. Those given the CD47 blocking antibody had startling results. Tumors almost universally shrank in weeks. And 5 out of five mice with implanted human breast cancer ended up being cancer free. On to human trials where anything could happen. However, one has to look at research like this and wonder if the illusive cure for cancer is near.