The Research On Apoptosis Induced By Quercetin In Human Gastric Cancer Cells

Objective: To study the effects of quercetin on proliferation and apoptosis in human gastric cancer cell line MGC-803.Methods: Cells were divided into the gastric cancer cells group(MGC-803 cells only)and the quercetin-treated group . The measurement of inhibitory rate and apoptotic index(AI)of quercetin were done by MTT assay and TUNEL assay; The positive expression rate of C-myc and P16 were detected by immunocytochemical staining. The expression of C-myc mRNA,P16 mRNA was observed by semiquantive reverse transcription polymerase chain reaction (RT-PCR).Results: Quercetin at concentrations ranging from 40μmol/L to 100μmol/L significantly inhibited the proliferation of MGC-803 cells in a dose- and time-dependent manner(P <0.01). TUNEL assay indicated that the number of apoptotic cells in quercetin-treated group was greater than that in the gastric cancer cells group (P <0.01).Expression of C-myc protein and C-myc mRNA decreased following quercetin induction, whereas P16 protein and P16mRNA expression increased significantly compared with the gastric cancer cells group(P <0.05).Conclusion: Quercetin could inhibit the growth and induce apoptosis of MGC-803 cells in a dose- and time-dependent manner. Its mechanisms may be relevant to the down- regulation of C-myc protein expression and C-myc mRNA expression as well as up regulation of P16 protein expression and P16 mRNA expression.