In earlier studies, the team also showed that AAV2 promotes cell death in cervical cancer cells infected with human papillomavirus (HPV).
Cells have different ways of dying. When a healthy cell gets damaged, or starts behaving in an abnormal way, this normally triggers production of proteins that cause apoptosis or cell suicide: part of this process also involves switching off proteins that trigger cell division. The problem with cancer cells is that apoptosis fails, and the proteins that regulate cell division and proliferation stay switched on, so abnormal cells continue to multiply and create new abnormal cells and that is how tumors develop.
Breast cancer is the most common cancer in the world and the main cause of cancer-related death in women.
First author Dr Samina Alam, research associate in microbiology and immunology at Penn State, told the press in a statement released on Thursday that breast cancer is also “complex to treat”.
Senior investigator Dr Craig Meyers, professor of microbiology and immunology at Penn State, explained why:
“Because it has multiple stages, you can’t treat all the women the same. Currently, treatment of breast cancer is dependent on multiple factors such as hormone-dependency, invasiveness and metastases, drug resistance and potential toxicities.”
However, he went on to say that in their study, they showed that “AAV2, as a single entity, targets all different grades of breast cancer”.
He and his team believe that AAV2 is switching back on the apoptosis pathways that were switched off in the cancer cells.
For their study they used lab tissue cultures of cancer cells and found AAV2 killed 100% of them within seven days, with most of the cell death proteins activated on day five.In another experiment, working with cancer cells from an aggressive form of breast cancer, they found the virus took three weeks to kill the cells.