目的:本研究系统地探讨了PGC对胃癌(GC)细胞的体外和体内生物学效应及其机制。
方法:通过EdU染色评估PGC在GC中的关键生物学作用,Hoechst染色,流式细胞术,小鼠模型,CCK-8,伤口愈合,transwell,和球体形成试验。通过液相色谱-质谱共免疫沉淀与IQ结构域GTP酶激活蛋白1(IQGAP1)的相互作用研究,免疫荧光染色,CHX-Chase测定,MG132测定,和qRT-PCR。
结果:PGC抑制增殖,生存能力,上皮-间质转化,迁移,入侵,和GC细胞的干性和促进GC细胞分化。PGC在体内抑制皮下肿瘤生长和腹膜播散。相互作用研究发现PGC通过下调IQGAP1蛋白和IQGAP1介导的Rho-GTP酶信号抑制抑制GC细胞迁移和侵袭。此外,PGC破坏IQGAP1蛋白的稳定性,促进其降解并显著缩短其半衰期。此外,PGC和IQGAP1在GC组织中的表达水平呈显著负相关。
结论:PGC可能在GC的发展和转移中起肿瘤抑制作用。PGC可以下调其相互作用蛋白IQGAP1并抑制Rho-GTPase通路,从而参与抑制GC细胞的迁移和侵袭。
OBJECTIVE: This study systematically explored the biological effects and mechanisms of PGC on gastric cancer (GC) cells in vitro and in vivo.
METHODS: The critical biological roles of PGC in GC were assessed via EdU staining, Hoechst staining, flow cytometry, mouse models, CCK-8, wound healing, transwell, and sphere-forming assays. The interaction study with IQ-domain GTPase-activating protein 1 (
IQGAP1) was used by Liquid chromatography-mass spectrometry co-immunoprecipitation, immunofluorescence staining, CHX-chase assay, MG132 assay, and qRT-PCR.
RESULTS: PGC inhibited the proliferation, viability, epithelial-mesenchymal transition, migration, invasion, and stemness of GC cells and promoted GC cell differentiation. PGC suppressed subcutaneous tumor growth and peritoneal dissemination in vivo. The interaction study found PGC inhibits GC cell migration and invasion by downregulating
IQGAP1 protein and
IQGAP1-mediated Rho-GTPase signaling suppression. In addition, PGC disrupts the stability of the
IQGAP1 protein, promoting its degradation and significantly shortening its half-life. Moreover, the expression levels of PGC and
IQGAP1 in GC tissues were significantly negatively correlated.
CONCLUSIONS: PGC may act as a tumor suppressor in the development and metastasis of GC. PGC can downregulate its interacting protein IQGAP1 and inhibit the Rho-GTPase pathway, thereby participating in the inhibition of GC cell migration and invasion.