In-Vitro Analysis of Glucose and Quercetin Effects on M-TOR and Nrf-2 Expression in HepG2 Cell Line (Diabetes and Cancer Connection)

Some types of cancers show a strong relationship with diabetes and play a central role in mortality in the patient population suffering from diabetes mellitus. In this study, HepG2 cells have been used to investigate the toxic effects of hyperglycemia and/or quercetin (Q) on mammalian target of rapamycin (m-TOR) and nuclear factor erythroid 2-related factor 2 (Nrf-2) expression as central molecules involved in cancer. HepG2 cells were cultured with different concentrations of glucose (5.5, 30, and 50 mM) and/or Q (25 µM) for 48 and 72 h. Effects of glucose and/or Q on m-TOR and Nrf-2 expression were assayed by quantitative real-time PCR (qRT-PCR). qRT-PCR results revealed that 30 and 50 mM of glucose increased m-TOR expression at 48 h, although after 72 h, only 30 mM had an increasing effect. At 50 mM, glucose-induced Nrf-2 gene expression after both 48 and 72 h. The results also showed that 25 µM of Q reduced m-TOR and Nrf-2 expression at both 30 and 50 mM after 48 and 72 h incubation. Q has potential effects on reducing oxidative stress caused by hyperglycemia and during diabetes may be able to modulate some carcinogenic signaling pathways.