Killing triple-negative breast cancer cells with virus

Due to the difficulties in fighting triple-negative breast cancer, novel ways of treatment are strongly desired. One of them might be application of viruses that would precisely attack the tumors. Recent study performer in Penn State College of Medicine has demonstrated that adeno-associated virus type 2 (AAV2) can significantly eradicate the cancer cells in mice. Importantly, the virus is known to infect humans but it does not cause any disease. The researchers reported that AAV2 killed 100 percent of triple-negative tumor cells via activating caspases, which are proteins involved in the process of programmed cellular death called apoptosis. It occurred that infected cells synthesized more Ki-67, a protein activating immune system and c-Myc, which triggers both cell growth and apoptosis. When AAV2 was injected into human breast cancer cell line-derived tumors in mice, tumor sizes decreased and the animals stayed alive during the study in contrast to untreated mice. The scientists underlined that the obtained results are crucial, as tumor death in response to therapy is also used as the measure of an effective chemotherapeutic.

Breast cancer is the most commonly diagnosed cancer in women, accounting for 28 percent of the total in the WHO European Region. The tumor cells substantially differ among patients, therefore different treatment approaches are applied. One of the classifications of breast cancer cells is based on the presence of three crucial receptors, which are estrogen receptor (ER), progesterone receptor (PR) and hormone epidermal growth factor receptor 2 (HER2). In case of triple-negative breast cancer cells, none of the aforementioned receptors is expressed. It means that the proliferation of cancer cells is not dependent on hormones, like estrogen or progesterone. Hence, hormonal therapies e.g. tamoxifen or therapies targeting HER2 receptors are not effective. Moreover, triple-negative cancer cells can be particularly aggressive and their recurrence is more probable than in case of other subtypes.

Future studies involving usage of AAV2 as a tool for eradication of triple-negative cancer cells may help in the development of more efficacious treatments of this aggressive breast cancer subtype.

Sources:

http://www.sciencedaily.com/releases/2014/06/140624110716.htm

http://www.euro.who.int/en/health-topics/noncommunicable-diseases/cancer/news/news/2012/2/early-detection-of-common-cancers/breast-cancer

http://www.breastcancer.org/symptoms/diagnosis/trip_neg

Maciej Smolarz