Regulation of cell proliferation and malignant potential by irisin in endometrial, colon, thyroid and esophageal cancer cell lines.

OBJECTIVE: Irisin is a novel hormone that has been proposed to mediate the beneficial effects of exercise on metabolism, including body weight regulation and insulin resistance. No previous studies have evaluated whether irisin may regulate cell proliferation and malignant potential of obesity-related cancer cell lines. MATERIALS/
METHODS: Cell proliferation and malignant potential i.e. cell adhesion and colony formation were studied in vitro using human and mouse obesity-related cancer cell lines i.e. endometrial (KLE and RL95-2), colon (HT29 and MCA38), thyroid (SW579 and BHP7) and esophageal (OE13 and OE33).
RESULTS: We observed that, in contrast to metformin, cell proliferation is not regulated by irisin in a dose-dependent manner in human and mouse obesity-related cancer cell lines. Specifically, physiological (5 to 10 nmol/L) and high physiological/pharmacological (50 to 100 nmol/L) concentrations of irisin had no effect on cell proliferation when compared to control in human and mouse endometrial, colon, thyroid and esophageal cancer cell lines. Also, we observed that, in contrast to metformin, neither physiological nor high physiological/pharmacological concentrations of irisin regulate cell adhesion and/or colony formation in human and mouse endometrial, colon, thyroid and esophageal cancer cell lines.
CONCLUSIONS: Our data suggest that irisin, in physiological and high physiological/pharmacological concentrations, has no in vitro effect on cell proliferation and malignant potential of obesity-related cancer cell lines. Future work is needed to determine the regulation of irisin levels and any physiological effects it may have on obesity-related cancers in vivo in animals and humans.