Can cancer develop from a virus and can humans catch these diseases from other animals? In an article linking breast cancer to mice, these provocative questions are raised in the January 19th issue of the British Journal of Cancer.
In the article, "Breast Cancer Incidence Highest in the Range of One Species of House Mouse, Mus Domesticus," the authors asserted that humans acquire the mouse mammary tumor virus from mice which sometimes leads to human breast cancer, a disease which claims the lives of over 40,000 women each year in the U.S. They pointed to studies that show a similar viral sequence between human breast cancer and mouse mammary tumor virus.
"This is a hypothesis, that if true, gives insight about this major disease, and more importantly provides a rational plan for a preventive vaccine," said Richard Sage, adjunct professor of biology at the University of California, Santa Barbara, and co-author of the article. "We're not speaking of a cure, but rather prevention."
The authors found that the highest incidence of human breast cancer worldwide occurs in lands where Mus domesticus (a type of house mouse) is the resident native or introduced species. "Given ... the near identity between human and mouse mammary tumor virus DNA sequences, and the close association between human breast cancer incidence and mouse ranges, we propose that humans acquire mouse mammary tumor virus from mice," said the authors.
The house mouse Mus domesticus is native from Western Europe to Iran, and introduced into North and South America, Australia, New Zealand and Hawaii. Inbred laboratory mice have mostly Mus domesticus genes.
The incidence of human breast cancer varies worldwide, a fact that has been known for decades. And it is higher in the above listed areas, where the Mus domesticus house mouse can be found, and lower in Eastern Europe, Japan and China, where this particular mouse is absent.