Is Alzheimer's Like a Strange Form of Brain Cancer?
Biochemist Peter Davies began investigating Alzheimer’s disease in the 1970s, long before its full impact became clear. By 2030 roughly 7.5 million Americans will have this debilitating neurodegenerative disorder. Already Alzheimer’s costs the country $148 billion a year; we urgently need to find the cause—and a cure. For years the prevailing theory was that memory loss was caused by protein fragments, so-called plaques and tangles, that accumulate in the brain. Davies, now at the Litwin-Zucker Center for the Study of Alzheimer’s Disease and Memory Disorders in Manhasset, New York, suspects a different culprit. His hunch is that the mechanisms controlling cell division have gone wrong—somewhat like what happens in cancer—and that plaques and tangles are the result. In the quest for answers, Davies has led hundreds of studies and examined more than 6,000 brains.
What is the central mystery of Alzheimer’s? The two main abnormalities of the disease are microscopic lesions called plaques and tangles, which occur in the brains of patients. This is how the disease was first recognized, in 1906. We want to know if these abnormalities are the result of the disease process or if they are abnormalities that cause the disease. That’s been the number-one question in the field for a long time, and there’s a lot of debate and disagreement about it—are the plaques and tangles cause or effect?
If we have known about Alzheimer’s since 1906, why do we still not understand it? By the time we get to look at the brain of a patient with Alzheimer’s, it’s really end-stage disease. Alzheimer’s is an agonizingly slow process, so by the time we get to study the disease itself during its late stages, all kinds of things have gone on that may be just consequences of disease rather than causal.
What is the most pressing issue today in the field of Alzheimer’s research? It’s really an issue of what comes first, the chicken or the egg. The majority of people in this field today believe that the plaques, made of a protein fragment called beta-amyloid pep tide (BAP), come first, and that the accumulation of this material causes the rest of the disease. We call them the BAPtists. The other side of the disease is the tangle, made of a protein called tau. TAUists believe that this protein comes first. If you are a BAPtist, you believe that the amyloid is the most important, so you work on ways to prevent or block the production or formation of amyloid in the brain.
But you don’t think Alzheimer’s is caused by either plaques or tangles, right? I believe these abnormalities are results of the disease process. We have looked at cancer cell processes in Alzheimer’s disease to see if they might have the ability to cause the disease and the plaques and tangles that are such striking features. I know it sounds off, that Alzheimer’s disease might be similar to brain cancer. But this came from work in my laboratory and others that suggested that nerve cells in affected regions of the Alz heimer brain looked like they were trying to divide. Several of the proteins characteristic of cancer cells seem to show up in these nerve cells, and this is very abnormal. One research group [led by a former student] made mice with adult brain cells and forced them with a viral gene to turn on cell-division machinery. What happened was dramatic: The mice showed the same evidence that cell division mechanisms were turned on, and then showed cell death, tangles, and plaques—a lot like Alzheimer’s disease. We are trying to find out exactly how and why the nerve cells in the Alzheimer’s brain decide to turn on their cell division system.
This is interesting. There were 9 in DH's family, counting mother and father. Everyone but DH had cancer. There have been 6 different types of cancer with one brother having 2 kinds. There are 2 surviving, a sister who had breast cancer and DH, who has only had some basil cell stuff on his face. Needless to say the C word always scared him to death. So far, I don't know any of the grandchildren having cancer.
Fascinating. My husband is one of 6 children. His father died of "atherosclerosis." His mother, two sisters, and one niece died of cancer. His two other sisters are cancer survivors. I've found it interesting that all of the woman in his immediate family had cancer, but he, his brother, and father didn't.
DH was one of 8 children. Several died from cancer, only two are still alive & became elderly. Two died from brain cancer. Parents died from cancer. I have always had a 'feeling' that much of the current AD research is on the wrong track. I also think diminished blood flow has a significant part to play. I know about plaques & tangles, but when I envision what is happening in the AD brain, I 'see' it as a cancer-destroying-cells event. I wouldn't say that it is cancer, per se, but that there is a connection of sorts is quite probable, in my layman's view. Anyway, I'll take this report over the 'crossword puzzles, exercise, eat right, yada yada' theory to avoid it.