Effects of leptin on cell proliferation and cytokine levels in human ovarian cancer cell lines ovcar-3 and mdah-2774

Obesity is closely linked to the development of various cancer types. Epidemiological and experimental studies have revealed the relationship between nutrition and cancer. Studies on which biological mechanisms and how obesity affects the cancer risk showed that there may be different mechanisms for different types of cancer. It is known that leptin levels in obese patients are higher than in normal population. Presence of leptin receptor expression in ovarian and existance of leptin in follicular fluid indicate that leptin plays a role in ovarian functions. In this study, it was aimed that to reveal the effects of leptin on cell proliferation and cytokine levels in human ovarian cancer cell lines OVCAR-3 and MDAH-2774. XTT test was used to evaluate the effect of increasing concentrations of leptin treatment (0.5 – 400 ng/ml) on cell proliferation in OVCAR-3 and MDAH-2774 cell lines at 24, 48 and 72 hours after 24h and 48h serum starvation, respectively. Human Cytokine Array was used to determine the changes in cytokine levels. The findings were evaluated by ANOVA followed by Dunnett's statistical analyzes. In our study it was observed that leptin treatment increased the cell proliferation after 24h and 48h serum starvation. The maximum effect was observed with a proliferation of 187.4% compared to control cells in OVCAR-3 cell line with 50 ng/ml leptin treatment at 24h after 48h serum starvation. The maximum effect was observed with a proliferation of 127.1% compared to control cells in MDAH-2774 cell line with 25 ng/ml leptin treatment at 72h after 24h serum starvation. As a result of leptin treatment, an increase in IL-3 and IL-10 levels, decrease in IL-2 level of interleukin family and decrease in MCP-2/CCL8 and MCP-3/CCL7 levels of chemokine family, an increase IGFBP-1, IGFBP-2 and IGFBP-3 levels of insulin-like growth factor binding protein family has been found in both of cell lines. An increase in IL-1 level in OVCAR-3 cell line, a decrease in antiangiogenic IFN-γ level and an increase TGF-β level that is inflamatuar cytokine has been detected in MDAH-2774 cell line. Epidemiological studies have shown that obesity increased the ovarian cancer incidance, life span and risk of relapse. This study may be a reference for the molecular mechanisms, which are not fully identified, underlying clinical observations. Key words: Leptin, ovarian cancer, obesity, cytokine, serum starvation.