Semaphorin 5A基因在胃癌侵袭和转移中的作用

目的探讨Semaphorin 5A基因在胃癌侵袭和转移中的作用机制。方法应用RNA干扰技术,构建Sema-phorin 5A-siRNA、Scrambled-siRNA表达载体,并分别转染胃癌细胞株SGC7901,建立Semaphorin 5A稳定表达抑制的胃癌细胞株SGC7901-Sema5A-si和对照组SGC7901-Scram-si胃癌细胞株;采用Western blotting、ELISA和RT-PCR方法,检测MMP2、MMP9在上述2种胃癌细胞株中的表达;应用MMP2、MMP9抗体处理胃癌细胞株,观察其对胃癌细胞株SGC7901-Sema5A-si和Semaphorin 5A侵袭、转移能力的影响。结果 SGC7901-Sema5A-si中MMP9表达水平明显低于SGC7901-Scram-si中的表达水平（P〈0.05）,MMP2在2种胃癌细胞株中表达水平无明显差异（P〉0.05）;MMP9抗体能够阻断Semaphorin 5A基因介导的胃癌侵袭和转移,MMP2抗体对Semaphorin 5A基因介导的胃癌侵袭和转移无影响。结论Semaphorin 5A可能通过MMP9表达促进胃癌发生侵袭和转移。

The Effect of Semaphorin 5A on Invasion and Metastasis of Gastric Cancer

Objective To examine functional mechanisms of Semaphorin 5A,an axon guidance factor,in the invasion and metastasis of gastric cancer.Methods The plasmids of expressing Semaphorin 5A siRNA and Scrambled-siRNA were constructed by using RNA interfere technique（RNAi） to generate gastric cancer cell lines SGC7901-Sema5A-si downregulating Semaphorin 5A and SGC7901-Scram-si as control group.The effect of Semaphorin 5 on the expression of MMP9 and MMP2 was examined by Western blotting、ELISA and RT-PCR assays,respectively.MMP9 and MMP2 antibodies were used to observe its effect on the metastasis and invasion of gastric cancer cells.Results MMP9 expression in SGC7901-Sema5A-si was lower than that in SGC7901-Scram-si whereas the expression level of MMP2 was not altered.MMP9 antibody could inhibit the invasive and metastatic activities of those cell lines induced by Semaphorin 5A.Conclusion Semaphorin 5A might enhance the invasion and metastasis of gastric cancer through expression of MMP9.