From a news release from Pennsylvania State University
A virus not known to cause disease
kills triple-negative breast cancer cells and killed tumors grown from these
cells in mice, according to Penn State College of Medicine
researchers. Understanding how the virus kills cancer may lead to new
treatments for TNBC.
Adeno-associated virus type 2 (AAV2)
infects humans but is not known to cause sickness. In prior studies, the
researchers tested the virus on a variety of breast cancers that represent
degrees of aggressiveness and on human papillomavirus-positive cervical cancer
cells. The virus initiated natural cell death in cancer cells without affecting
healthy cells.
"Treatment of breast cancer
remains difficult because there are multiple signaling pathways that promote
tumor growth and develop resistance to treatment," said Craig Meyers,
Ph.D., Distinguished Professor of Microbiology and Immunology.
Signaling pathways involve molecules
in a cell that control cell functions—such as cell division. For example, the
first molecule in the process receives a signal to begin. It then tells another
molecule to work, and so on.
"There is an urgent and ongoing
need for the development of novel therapies which efficiently target
triple-negative breast cancers," Meyers said.
In the current study, the researchers
tested AAV2 on a cell-line representative of triple-negative breast cancer. The
researchers report their results in Cancer Biology & Therapy.
The AAV2 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, consistent with past
studies, AAV2-infected cancer cells produced more Ki-67, an immunity system activating
protein and c-Myc, a protein that helps both to 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.
The researchers then injected AAV2
into human breast cancer cell line-derived tumors in mice without functioning
immune systems. Mice that received AAV2 outlived the untreated mice and did not
show signs of being sick, unlike the untreated mice. Tumor sizes decreased in
the treated mice, areas of cell death were visible and all AAV2 treated mice
survived through the study, a direct contrast to the untreated mice.
"These results are significant,
since tumor necrosis, or death, in response to therapy is also used as the
measure of an effective chemotherapeutic," Meyers said.
Future studies should look at the use of AAV2 body-wide in
mice, which would better model what happens in humans, according to Meyers.
Please support this site with your donations—that's what keeps it going. Plus, if you donate just $25 you'll receive a copy of my book, Surviving Triple-Negative Breast Cancer. Click the Donate button on the right to donate through PayPal. You'll then get an email from me asking if you want the book, how you want it signed and where you want it sent. And if you just want to donate without receiving the book, that's wonderful. Thanks! And hugs.
Please support this site with your donations—that's what keeps it going. Plus, if you donate just $25 you'll receive a copy of my book, Surviving Triple-Negative Breast Cancer. Click the Donate button on the right to donate through PayPal. You'll then get an email from me asking if you want the book, how you want it signed and where you want it sent. And if you just want to donate without receiving the book, that's wonderful. Thanks! And hugs.