FAM49B在胃癌中的表达及临床意义的生物信息学分析与实验验证

Bioinformatic analysis and experimental validation of FAM49B expression and its clinical significance in gastric cancer

背景与目的:胃癌是一种在全球范围内极为普遍的恶性肿瘤,其发生率之高使其成为全球癌症死亡的一个重要因素。研究发现,序列相似性家族49成员B(FAM49B)在包括胃癌在内的大多数肿瘤中显著上调,但FAM49B在胃癌发生和发展中的角色,目前仍然知之甚少。因此,本研究探讨FAM49B在胃癌中的作用及机制,以期为胃癌的治疗提供新的途径。方法:基于TCGA和GEO数据库,进行FAM49B的表达、生存分析、免疫浸润评估、基因集富集及蛋白质相互作用(PPI)网络分析。收集胃癌临床样本,采用免疫组化、qRT-PCR和Westernblot检测FAM49B的表达水平,并分析其表达与患者临床病理因素的关系。体外实验分析FAM49B在胃癌细胞系中的表达,并采用CCK-8、EdU、Transwell和流式细胞术分析FAM49B对胃癌细胞增殖、迁移、侵袭及细胞周期的影响。结果:生物信息学分析显示,FAM49B基因在胃癌的肿瘤组织中呈明显高表达,同时FAM49B的高表达与M1/M2巨噬细胞极化过程密切相关,FAM49B高表达的胃癌患者预后更好;富集分析显示,FAM49B高表达组富集于p53信号通路,而低表达组富集于ERBB信号通路,PPI网络分析显示,FAM49B与FAM49A、ACTN1、THSD4、RAC3、EGFR等蛋白有高度相互作用。在胃癌组织和细胞系中,FAM49B的mRNA和蛋白表达均明显上调(均P<0.05);FAM49B的表达与肿瘤大小及胃癌的浸润深度呈反向关系(均P<0.05)。敲除FAM49B基因后,胃癌细胞的增殖和转移能力明显增强,而过表达FAM49B后则成反向变化(均P<0.05);敲除FAM49B的胃癌细胞G1期比例明显降低,S期升高,伴随cyclin E1和cyclin D1蛋白表达下调,而过表达FAM49B的胃癌细胞G1期百分比升高,S期和G2期百分比降低,伴随cyclinE1和cyclinD1蛋白表达上调(均P<0.05)。此外,敲除FAM49B后,胃癌细胞中N-cadherin、vimentin及c-myc表达上调,p53表达下调,而过表达FAM49B后,胃癌细胞中这些蛋白的表达呈反向变化。结论:FAM49B在胃癌中呈现高表达,但其发挥了抑癌作用。其作用机制可能与调控巨噬细胞极化、上皮-间充质转化以及p53通路有关。

Background and Aims:Gastric cancer is a highly prevalent malignant tumor worldwide,with a high incidence rate that makes it a significant contributor to global cancer mortality.Studies have found that FAM49B is significantly upregulated in most tumors,including gastric cancer.However,the role of FAM49B in the occurrence and development of gastric cancer remains largely unknown.Therefore,this study explores the role and mechanisms of FAM49B in gastric cancer,aiming to provide new avenues for gastric cancer treatment.Methods:Based on TCGA and GEO databases,the analyses of FAM49B expression,survival,immune infiltration,gene set enrichment,and protein-protein interaction(PPI)networks were conducted.Gastric cancer clinical samples were collected,and immunohistochemistry,qRT-PCR,and Western blot were used to assess FAM49B expression levels and analyze their relationship with patients'clinicopathological factors.In vitro experiments analyzed FAM49B expression in gastric cancer cell lines,using CCK-8,EdU,Transwell,and flow cytometry assays to examine the effects of FAM49B on gastric cancer cell proliferation,migration,invasion,and cell cycle process.Results:Bioinformatic analysis showed that FAM49B was significantly overexpressed in gastric cancer tumor tissues,with high FAM49B expression closely related to M1/M2 macrophage polarization,and patients with high FAM49B expression in gastric cancer had better prognosis.Enrichment analysis revealed that the high FAM49B expression group was enriched in the p53 signaling pathway,while the low FAM49B expression group was enriched in the ERBB signaling pathway.PPI network analysis indicated a strong interaction between FAM49B and proteins such as FAM49A,ACTN1,THSD4,RAC3,and EGFR.In both gastric cancer tissues and cell lines,FAM49B mRNA and protein expression were significantly upregulated(both P<0.05).FAM49B expression showed an inverse correlation with tumor size and gastric cancer invasion depth(both P<0.05).After FAM49B knockdown,gastric cancer cell proliferation and migration abilities significantly increased,while FAM49B overexpression had the opposite effect(both P<0.05).Knockdown of FAM49B reduced the percentage of cells in G1 phase and increased the percentage in S phase,accompanied by downregulated expression of cyclin E1 and cyclin D1,while FAM49B overexpression led to an increase in G1 phase cells and a decrease in S and G2 phase cells,with upregulation of cyclin E1 and cyclin D1(both P<0.05).Additionally,after FAM49B knockdown,N-cadherin,vimentin,and c-myc expression increased,while p53 expression decreased,whereas FAM49B overexpression produced the opposite effect on these proteins in gastric cancer cells.Conclusions:FAM49B is highly expressed in gastric cancer but exhibits tumor-suppressing effects.Its mechanisms may be related to the regulation of macrophage polarization,epithelial-mesenchymal transition,and the p53 pathway.