Scientists at New York's Colombia University Institute for Cancer Research have been working recently on the theory that there may be a strong link between a virus and human breast cancer.
Scientists at New York's Colombia University Institute for Cancer Research have been working recently on the theory that there may be a strong link between a virus and human breast cancer. A research team led by Dr. Saul Spiegelman investigated the links between the genetic material in human and mice -- and it's known that a virus cases breast cancer in mice.
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SYNOPSIS: In this dish is cancer in one of its most deadly forms -- the breast tumour. In the United States alone, it's one of the worst killers. Breast tumours claim the lives of 31,000 American women annually -- more than any other form of cancer.
Before breast cancer can be cured, scientists must find out what causes it. Doctors at the Columbia University Institute of Cancer Research in New York are currently examining the theory that there's link between breast cancer and a virus. As a first step, tumours are ground up in a laboratory. Scientists then extract from each tumour what's called the genetic information. This is the small quantity of genetic material in each cell which directs all of the cell's activity. In normal cells, the genetic material dictates normal growth. But in cancer cells something goes wrong. Then, growth is wild, rapid and uncontrollable.
Breast cancer affects animals as well as humans. In mice and other animals, scientists know it's caused by a virus. In some strains of mice the virus is present in the mother's milk. So the technicians take milk from the mice. Then, from the virus in the milk they extract microscopic particles of genetic material. They know this material directs the growth of cancer in the mouse. (PAUSE) And they suspect that similar genetic material may well be at the root of human breast cancer.
In the past year, these scientists have turned up strong evidence to support their theories. They have found particles in the milk of women with strong family histories of breast cancer. These particles are physically and chemically very much alike the cancer-causing virus in the milk of mice. In these pictures, the human particles are at the top.
Most recent experiments have been directed at finding yet another piece of evidence. Scientists are trying to prove that the complete virus which causes breast cancer in mice contains genetic materials similar to that in human breast material. (PAUSE) The scientist look for this evidence by mixing the genetic material from mouse virus with that extracted from a human tumour.
If the two genetic particles join into a single molecule, that, the scientists say, proves the similarity. Measurements in recent experiments show this happened in 17 out of 24 cases -- about 71 per cent. But when non-cancerous breast tissue was mixed with mouse virus, a single molecule never resulted.
Dr. Saul Spiegelman, a well-known American molecular biologist, led the study team at the cancer research institute. He doesn't claim that the studies have proved beyond dispute that a virus cases human breast cancer. He does believe, however, that his studies have produced evidence so strong that the likelihood is great.