[Quercetin affects leptin and its receptor in human gastric cancer MGC-803 cells and JAK-STAT pathway].

Aim: Quercetin affects the expressions of leptin and its receptor in human gastric cancer MGC-803 cells and JAK-STAT pathway.

Methods: The cultured MGC-803 cells were divided into three groups:

Control Group: the cultured cells without quercetin, and Quercetin group: the cultured cells with quercetin(40 μmol/L), and AG490group: the cultured cells with AG490(40 μmol/L)The expressions of Leptin, Leptin receptor and P-STAT3 were detected in protein level by immunocytochemical and Western bloting method respectively. The expressions of Leptin, Leptin receptor were detected in mRNA level by RT-PCR method. MGC-803 cell cycle was arrest by flow cytometry (FCM); MGC-803 cell apoptosis ratio by apoptotic marker An-necxinV.

Results: The protein expression of Leptin, Leptin receptor, P-STAT3 and the the mRNA expression of Leptin and Leptin receptor were significantly increased (P<0.05), compared with the control group.There was the rectilinear correlation relationship not only between Leptin and P-STAT3 protein(r=0.741, P<0.05) but also between Leptin receptor and P-STAT3 protein(r=0.693, P<0.05). FCM analysis showed that quercetin arrested MGC-803 cells at the G2/M phase, The ratio of apoptotic and necrosic cells increased with added quercetin concentration.

Conclusion: Quercetin could inhibit the Proliferation of MGC-803 cells. It is probably relevant to the down-regulation the expressions of Leptin and Leptin receptor protein, Leptin mRNA and Leptin receptor mRNA by JAK-STAT pathway.