OBJECTIVETo investigate the role of Notch1 in the proliferation, migration and invasion of gastric cancer cells.

METHODSNotch1 expression was detected by RT-PCR and Western blot in four gastric cancer cell lines(SGC-7901, BGC-823, MKN-45 and MKN-28). The RNAi segments targeting Notch1 were designed and transfected into cell lines with the highest level of Notch1. The transcription and translation level of Notch1 expression was detected by real-time PCR and Western blot. The proliferation of transfected cells were determined by CCK8 test. Meanwhile, the migration and invasive ability of transfected tumor cells were detected by Transwell test.

RESULTSGastric cell line BGC-823 was selected with the highest expression of Notch1 at both mRNA level and protein level. The expression of Notch1 was significantly reduced after the transfection. The CCK8 test showed the growth rate was significantly reduced in RNAi group after two days(F=4.644, P=0.046). In migration test, the number of cells crossing through chambers in RNAi group(30.1±3.1) was significantly lower than that in the negative control group(44.5±3.2) and in the mock group(46.1±2.6)(P<0.05). In invasion test, the number of cells crossing through chambers in RNAi group(22.9±4.5) was also significantly lower than that in the negative control group (37.3±4.2) and in the mock group (37.8±3.7)(P<0.05).

CONCLUSIONDown-regulation of Notch1 inhibits the proliferation and reduces the ability of migration and invasion in gastric cell line BGC-823, suggesting that Notch1 may play an important role in the gastric carcinogenesis and metastasis.