Wang Li, Guo Jianghong, Lv Caixia, Kong Luke, Cui Jing, Wang Zhongshuai, Guo Yuanyuan, Jia Ruirui, Guan Tao, Yu Baofeng, Li Feng
Department of Biochemistry and Molecular Biology, Shanxi Key Laboratory of Birth Effects and Cell Regeneration, MOE Key Laboratory of Coal Environmental Pathogenicity and Prevention, MOE Key Laboratory of Cellular Physiology, Shanxi Medical University, Taiyuan, China.
Department of Central Laboratory, Shanxi Province Cancer Hospital/Shanxi Hospital Affiliated to Cancer Hospital, Chinese Academy of Medical Sciences/Cancer Hospital Affiliated to Shanxi Medical University, Taiyuan, Shanxi, China.
Front Cell Dev Biol. 2025 Aug 7;13:1619359. doi: 10.3389/fcell.2025.1619359. eCollection 2025.
This study aimed to explore the dysregulation of miR-145-5p in gastric cancer (GC) and its effects on the proliferation and cell cycle of GC cells, exploring the potential regulatory mechanism of miR-145-5p in GC.
In this study, the TCGA database combined with Microarray was used to detect differentially expressed microRNA (miRNA) in GC tissues and cells. Quantitative real-time (qRT)-PCR was used to further verify the expression of miR-145-5p in GC cells and the 41 pairs of GC tissues and adjacent tissues. A retrospective analysis was conducted on the correlation between miR-145-5p and the clinicopathological characteristics of patients with GC. The proliferation ability and cell cycle of AGS and MKN28 were detected by CCK-8, Edu and flow cytometry. The downstream target genes of miR-145-5p were screened by bioinformatics and further verified by the dual-luciferase reporter assay. Immunohistochemistry was used to detect the expression of SMAD5 in GC tissues. Western blot was used to detect cell cycle-related proteins that were regulated by siRNA SMAD5.
The expression of miR-145-5p was lower in GC tissues and cells compared with adjacent tissues and GES-1, and was related to the poor prognosis of patients with GC. Overexpression of miR-145-5p inhibited the proliferation of GC cells and blocked the cell cycle from G1 phase to S phase. MiR-145-5p targeted SMAD5 to inhibit the proliferation, and arrested the G1/S phase transition of GC cells. Mechanistically, SMAD5 siRNA significantly reduced CCND1 protein expression, Bioinformatics databases predicted that cyclin D1 was the transcription target gene of SMAD5. Moreover, the re-expression of cyclin D1 partially reversed the cell cycle arrest that was induced by SMAD5 depletion in GC cells.
Taken together, these findings reveal a novel role of the miR-145-5p/SMAD5/cyclin D1 axis in modulating cell cycle progression and cell proliferation in GC, which may provide a prognostic biomarker for GC treatment.
本研究旨在探讨miR-145-5p在胃癌（GC）中的表达失调及其对GC细胞增殖和细胞周期的影响，探索miR-145-5p在GC中的潜在调控机制。
本研究利用TCGA数据库结合微阵列检测GC组织和细胞中差异表达的微小RNA（miRNA）。采用定量实时（qRT）-PCR进一步验证miR-145-5p在GC细胞以及41对GC组织和癌旁组织中的表达。对miR-145-5p与GC患者临床病理特征之间的相关性进行回顾性分析。通过CCK-8、Edu和流式细胞术检测AGS和MKN28的增殖能力和细胞周期。通过生物信息学筛选miR-145-5p的下游靶基因，并通过双荧光素酶报告基因实验进一步验证。采用免疫组织化学检测GC组织中SMAD5的表达。使用蛋白质免疫印迹法检测受siRNA SMAD5调控的细胞周期相关蛋白。
与癌旁组织和GES-1相比，miR-145-5p在GC组织和细胞中的表达较低，且与GC患者的不良预后相关。miR-145-5p的过表达抑制了GC细胞的增殖，并使细胞周期从G1期阻滞到S期。miR-145-5p靶向SMAD5以抑制增殖，并使GC细胞的G1/S期转换停滞。机制上，SMAD5 siRNA显著降低CCND1蛋白表达，生物信息学数据库预测细胞周期蛋白D1是SMAD5的转录靶基因。此外，细胞周期蛋白D1的重新表达部分逆转了GC细胞中由SMAD5缺失诱导的细胞周期停滞。
综上所述，这些发现揭示了miR-145-5p/SMAD5/细胞周期蛋白D1轴在调节GC细胞周期进程和细胞增殖中的新作用，这可能为GC治疗提供一种预后生物标志物。
