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


METHODS
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.


CONCLUSIONS
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.
Institute of Cellular and Molecular Biology, College of Medical Science, Wuhan University of Science and Technology, Wuhan 430065, China. qinyan3882@sina.com
Yan
Y
Qin
Li-ya
LY
He
Yong
Y
Chen
Wen-yi
WY
Wang
Xue-hua
XH
Zhao
Mian-yun
MY
Wu
D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D002453:Cell Cycle / Q000187:drug effects / Q000235:genetics; D045744:Cell Line, Tumor; D006801:Humans; D053612:Janus Kinases / Q000378:metabolism*; D020738:Leptin / Q000378:metabolism*; D011794:Quercetin / Q000494:pharmacology*; D054411:Receptors, Leptin / Q000235:genetics / Q000378:metabolism*; D050791:STAT Transcription Factors / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism*
D000975:Antioxidants; D020738:Leptin; D054411:Receptors, Leptin; D050791:STAT Transcription Factors; D011794:Quercetin; D053612:Janus Kinases