背景:衰老标记蛋白30(SMP30)是一种钙结合蛋白,其表达随年龄增长而降低,并与肝细胞癌(HCC)的发展密切相关。本研究的主要目的是检查SMP30对HCC迁移和侵袭的机制作用。
方法:采用生物信息学和免疫组织化学方法检测肝癌组织中SMP30的表达及其与患者生存的关系。我们研究了SMP30表达对肝癌细胞增殖的影响,迁移,入侵,和细胞周期动力学。cDNA微阵列技术用于确定重组SMP30过表达后SK-Hep-1细胞的基因表达谱,以鉴定SMP30下游调节HCC细胞迁移和侵袭的基因。我们通过亲和纯化-质谱(AP-MS)和共免疫沉淀/蛋白质印迹(COIP-WB)鉴定了SMP30相互作用蛋白。
结果:SMP30在肝癌组织中的表达低于正常肝组织,其表达与HCC患者的总生存期呈正相关。此外,SMP30过表达有效阻断SK-Hep-1细胞的迁移和侵袭特性,但不影响增殖率或细胞周期。cDNA微阵列结果证实,鉴定出的许多差异表达基因参与上皮-间质转化(EMT)的过程。AP-MS和COIP-WB实验证实,Rho相关蛋白激酶1(ROCK1)与SK-Hep-1细胞中的SMP30相互作用,已知ROCK1密切调节EMT过程。
结论:SMP30通过与ROCK1相互作用后影响EMT相关蛋白的表达,从而抑制HCC转移。
BACKGROUND: The senescence marker protein 30 (SMP30) is a calcium-binding protein whose expression decreases with age, and is closely associated with hepatocellular carcinoma (HCC) development. The primary goal of this study was to examine the mechanistic effect of SMP30 on HCC migration and invasion.
METHODS: Bioinformatic and immunohistochemical approaches were used to examine the expression of SMP30 in HCC tissues and its relationship to patient survival. We investigated the effects of SMP30 expression on HCC cell proliferation, migration, invasion, and cell cycle dynamics. cDNA microarray technology was used to determine the gene expression profile of SK-Hep-1 cells following recombinant SMP30 overexpression to identify genes downstream of SMP30 that regulate HCC cell migration and invasion. We identified SMP30 interacting proteins by affinity purification-mass spectrometry (AP-MS) and co-immunoprecipitation/western blotting (COIP-WB).
RESULTS: SMP30 expression was lower in HCC tissues compared with normal liver tissues, and its expression positively correlated with overall survival in HCC patients. Additionally, SMP30 overexpression effectively blocked the migratory and invasive properties of SK-Hep-1 cells, but did not affect either proliferation rates or cell cycle. cDNA microarray results confirmed that many of the differentially expressed genes identified are involved in the process of epithelial-mesenchymal transition (EMT). AP-MS and COIP-WB experiments confirmed that Rho-associated protein kinase 1 (ROCK1) interacts with SMP30 in SK-Hep-1 cells, and ROCK1 is known to intimately regulate the EMT process.
CONCLUSIONS: SMP30 inhibits HCC metastasis by influencing the expression of EMT-related proteins after interacting with ROCK1.