CADM1过表达对人胃癌MKN-45细胞增殖和侵袭的影响及其分子机制

 目的：研究细胞黏附分子1（cell adhesion molecule 1，CADM1）过表达对人胃癌MKN-45细胞增殖和侵袭的影响并探讨其可能的分子机制。方法：采用Western blotting检测3株胃癌细胞系中CADM1蛋白的表达。构建pcDNA-CADM1真核表达载体，并将其转染MKN-45细胞，采用G418筛选稳定表达CADM1的细胞株，利用Western blotting鉴定所筛选的稳定细胞株。采用CCK-8试剂和Boyden小室分析过表达CADM1对MKN-45细胞增殖和侵袭的影响。利用Western blotting检测细胞增殖和侵袭相关蛋白表达。结果：MKN-45细胞中CADM1蛋白的相对表达水平显著低于MKN-28和SGC-7901细胞（P<0.05）。此外，成功构建pcDNA-CADM1真核表达载体，并获得稳定过表达CADM1的MKN-45细胞株。CCK-8结果显示，与未处理组和pcDNA3.1组相比，pcDNA-CADM1组中MKN-45细胞的增殖明显受到抑制（P<0.05）。Boyden小室体外侵袭实验结果显示，与未处理组（101.53±6.89）和pcDNA3.1组（98.77±7.03）相比，pcDNA-CADM1组中MKN-45细胞穿膜的细胞数（52.35±3.89）显著减少（P<0.05）。Western blotting结果显示，与未处理组和pcDNA3.1组相比，pcDNA-CADM1组中p21蛋白表达显著上调，而MMP-2和MMP-9表达显著下调（P<0.05）。结论：CADM1过表达能明显抑制胃癌细胞的增殖和侵袭能力，因而CADM1有望成为胃癌治疗的新靶点。

Effects of CADM1 overexpression on proliferation and invasion of human gastric carcinoma cell line MKN-45

AIM: To investigate the effects of CADM1 overexpression on proliferation and invasion of human gastric carcinoma cell line MKN-45. METHODS: The protein levels of CADM1 in 3 human gastric carcinoma cell lines were detected by Western blotting. Eukaryotic expression vector pcDNA-CADM1 was constructed and transfected into MKN-45 cells. The MKN-45 cells stably expressing CADM1 were selected by G418 and identified by Western blotting. Furthermore, CCK-8 assay and Boyden chamber were used to analyze the effects of CADM1 overexpression on the prolife ration and invasion of gastric carcinoma cells. Western blotting was also utilized to detect the levels of cell proliferation- and invasion-related proteins. RESULTS: Relative level of CADM1 protein in MKN-45 cells was significantly lower than that in MKN-28 cells and SGC-7901 cells. Additionally, eukaryotic expression vector pcDNA-CADM1 was successfully constructed and MKN-45 cells stably expressing CADM1 were obtained. Compared with non-treatment and pcDNA3.1 groups, the proliferation of MKN-45 cells was obviously inhibited in pcDNA-CADM1 group. The result of Boyden chamber showed that the migrated cell numbers in pcDNA-CADM1 group (52.35±3.89) were significantly lower than that in untreated group (101.53±6.89) and pcDNA3.1 group (98.77±7.03). Compared with non-treatment and pcDNA3.1 groups, the protein level of p21 was significantly up-regulated and protein expression of MMP-2 and MMP-9 was obviously down-regulated. CONCLUSION: Overexpression of CADM1 may markedly inhibit cell proliferation and reduce invasion ability, and thus may be a novel target for treating gastric carcinoma.