A new study in Cancer Biology & Therapy concluded that a virus not known to cause disease kills triple-negative breast cancer cells and kills tumor growth from those cells in mice. The virus, adeno-associated virus type 2 (AAV2), infects humans but is not known to cause illness. In previous studies the virus initiated apoptosis (natural cell death) in cancer cells but did not alter normal cells.
In this study the researchers tested AAV2 on a cell-line representative of triple-negative breast cancer. The AAV@ killed 100 percent of the cells in the laboratory by activating proteins called caspases, which are essential for the cell’s natural death. In addition, like past study results AAV2-infected cancer cells produced more Ki-67 an immunity system activating protein and e-mYc, a protein that helps to both increase cell growth and induce apoptosis. The cancer cell growth slowed by day 17 and all cells were dead by day 21. AAV2 mediated cell killing of multiple breast cancer cell lines representing both low and high grades of cancer and targeted the cancer cells independent of hormone or growth factor classification.
Researchers then injected AAV2 into human breast cancer cell line-betided tumors in mice without functioning immune systems. Mice that received AAV2 outlived the mice that were untreated and did not show signs of being sick like the untreated ones. Tumor sizes decreased in the treated mice, areas of cell death were visible and all treated mice survived through the study whereas the untreated one did not. Further studies are planned.