CANNFLAVINS A AND B EXERT ANTI-CANCER EFFECTS IN CHEMOTHERAPEUTIC RESISTANT BREAST CANCER CELL LINES

Abstract

1 in 8 women in Canada will be diagnosed with breast cancer in their lifetime and although survival rates have increased due to increased screening and improved therapies chemotherapeutic resistance can limit treatment options and lead to a poorer prognosis. There is a clear need for novel treatment options to help patients who have reduced survival rates due to chemotherapeutic resistance. Studies have shown many compounds found in Cannabis sativa can exert anti-cancer effects in vitro and in vivo. Interestingly little is known about cannflavin A and B, two flavonoids present in Cannabis, and their role in chemotherapeutic breast cancer. This study showed that cannflavin A and B reduced the cell viability of taxol-resistant breast cancer cell lines in a dose-dependent manner while not affecting the viability of a non-tumorigenic breast cell line. Cannflavins A and B induced apoptosis, promoted autophagy, and reduced invasiveness of the chemotherapeutic resistant breast cancer cells. When combined with the cannabinoid THC or the chemotherapeutic agent paclitaxel Cannflavin A and B produced variable responses–from antagonistic to additive, and even synergistic, depending on the concentrations used. Some combinations of cannflavins and THC or paclitaxel significantly reduced cell viability and acted synergistically. Results indicate that cannflavin A and B, two lesser characterized compounds from Cannabis, can reduce the viability of taxol-resistant breast cancer cells. These compounds can act synergistically with cannabinoids and paclitaxel. Future studies should be completed in in vivo models to confirm the anti-cancer effects of cannflavin A and B.