[Abstract] Objective: To analyze the expression level of miR-224 in cancer tissues and plasma of hepatocellular carcinoma (HCC) patients, and its correlation with clinicopathological characteristics, diagnosis and prognosis of HCC patients, and to further analyze its mechanism of action in the occurrence and development of liver cancer through bioinformatics analysis and in vitro experiments. Methods: The expression level of miR-224 in HCC tissues and normal tissues was analyzed using large sample data from Gene Expression Omnibus (GEO). qPCR method was used to verify the expression level of miR-224 in the tumor tissues and corresponding adjacent tissues that surgically resected from 80 HCC patients in Hebei Provincial People ’s Hospital from January 2017 to January 2020; in addition, the miR-224 level was also examined in plasma samples from 30 HCC patients. The Kaplan-Meier plotter database was used to analyze the correlation between the miR-224 expression and the overall survival time of HCC patients. The biological processes and signal pathways involving miR-224 were analyzed using bioinformatics tools. Hepatocellular carcinoma HepG2 cells were transfected with miR-224 inhibitor, and then Clone formation experiment, Transwell chamber experiment, qPCR and WB methods were used to detect the effect of miR-224 knockdown on the proliferation and invasion of HepG2 cells and the expression level of EMT-related molecules. Results: The results of GEO database analysis showed that the expression level of miR-224 in HCC tissues was significantly higher than that in normal tissues. The results of clinical specimen verification showed that the expression level of miR-224 in the tumor tissues and plasma of HCC patients was significantly higher than that in the corresponding adjacent tissues and plasma from healthy controls (all P<0.01). The expression level of miR-224 was significantly correlated with the TNM stage, lymph node metastasis status and tumor size of HCC patients (P<0.05 or P<0.01). ROC analysis indicated that miR-224 showed a prominent diagnostic value in liver cancer, and the increased expression level of miR-224 was significantly related to the poor prognosis of HCC patients (P<0.05). Functional enrichment analysis revealed that miR-224 was mainly involved in the mTOR signaling pathway, AGE-RAGE signaling pathway, Rap1 signaling pathway, Ras signaling pathway, ErbB signaling pathway, HIF-1 signaling pathway and p53 signaling pathway and other signaling pathways related to tumor occurrence and development. Knockdown of miR-224 could significantly inhibit the colony formation and invasion of HepG2 cells and affect the expression of EMT-related markers (P<0.05 or P<0.01). Conclusion: miR-224 is highly expressed in HCC tissues and plasma and is significantly related to the poor prognosis of HCC patients. Knockdown of miR-224 expression can inhibit the colony formation, invasion and EMT process of liver cancer HepG2 cells.

Aim To investigate whether diallyl disul¬fide ( DADS) downregulates X-linked inhibitor of ap- optosis protein ( XIAP) through miR-7 , inhibiting the proliferation, migration anrl invasion of gastric eaneer SGC7901 eel Is.Methods Gastric eaneer SGC7901 eell line overexpressing XIAP was established.qRT- PCR and Western blot were used to deteet the effeet of DADS on XIAP expression in overexpressed eells.CCK-8 and plate elone formation assay were used to analyze the effeet of DADS on the proliferation of XIAP overexpressing eells.Wound healing and Transwell ex¬periments were employed to analyze the effeets of DADS on the migration and invasion of XIAP overex¬pressing eells.qRT-PCR was used to deteet the effeet of DADS on the expression of miR-7.Negative regula¬ tion of miR-7 on XIAP was verified by using dual lucif- erase reporter gene assay, qRT-PCR ,anrl Western blot.Results XIAP overexpression enhanced the prolifera¬tion , migration and invasion of SGC7901 cells.DADS downregulated XIAP and inhibited the proliferation, mi¬gration and invasion of XIAP overexpressing cells.DADS upregulated miR-7 expression.miR-7 bound and regulated XIAP 3 'UTR directly.Overexpression of miR-7 decreased XIAP expression,while knockdown of miR-7 increased XIAP expression.Conclusion DADS downregulates XIAP through miR-7 to inhibit SGC7901 cell proliferation, migration and invasion.

[摘 要] 目的：采用生物信息学方法分析E3泛素连接酶（HECW2）在胃腺癌组织中的表达及其临床意义，为寻找胃腺癌诊断和预后生物标志物提供新的线索。方法：用R语言分析HECW2在泛癌中的表达及其与泛癌预后的关系。借助UCSC Xena、HPA、Kaplan-Meier Plotter等数据库分析HECW2在胃腺癌组织中的表达及其与临床病理特征之间的关系。采用WB法检测中国人胃腺癌组织及其癌旁组织中HECW2蛋白水平以验证数据库中的分析结果。借助TIMER和Cibersort数据库分析HECW2与胃腺癌免疫浸润的关系。通过LinkedOmics数据库对胃腺癌中HECW2进行GO功能分析和KEGG信号通路富集分析及相关性基因分析。结果：生物信息学分析结果表明，33种不同类型肿瘤中，包括胃腺癌在内的12种肿瘤中HECW2呈显著高表达（均P<0.05），WB法结果显示，中国人胃腺癌组织中HECW2也呈显著高表达（P<0.05）。HECW2表达水平越高，胃腺癌患者OS越短，包括CD4+ T细胞、巨噬细胞、中性粒细胞和树突状细胞在内的免疫细胞浸润丰度越高（均P˂0.01）。此外，HECW2相关信号通路主要富集于细胞外基质受体相互作用、黏着斑、细胞黏附和氧化磷酸化等生理病理过程（均P˂0.01）。结论：HECW2在胃腺癌组织中呈显著高表达且其与胃腺癌预后不良和免疫细胞浸润密切相关，有成为胃腺癌预后标志物和治疗靶点的潜力。