Yang Yang, Hou Ni, Wang Xiaofei, Wang Lumin, Chang Su'e, He Kang, Zhao Zhenghao, Zhao Xiaoge, Song Tusheng, Huang Chen
Department of Genetics and Molecular Biology, Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi, China.
Key Laboratory of Environmentally and Genetically Associated Diseases at Xi'an Jiaotong University, Ministry of Education, Xi'an, Shaanxi, China.
Oncotarget. 2015 Jun 30;6(18):16227-38. doi: 10.18632/oncotarget.3970.
In human hepatocellular carcinoma (HCC), aberrant expression of miRNAs correlates with tumor cell proliferation, apoptosis, invasion, and migration by targeting downstream proteins. miR-15b levels are reported increased in HCC tissues; however, they negatively correlate to HCC recurrence. Our aim was to understand the reason for this phenomenon. We used the reverse transcription-polymerase chain reaction (RT-PCR) to measure miR-15b-5p expression in both HCC tissues and HCC cell lines. Our results were consistent with the report. Using bioinformatics and luciferase reporter assays, we identified Rab1A as a novel and direct target of miR-15b-5p. Inhibiting the function of Rab1A with shRab1A also inhibited the growth of HCC cells and induced endoplasmic reticulum stress (ERS) and apoptosis. Similarly, suppressing Rab1A by overexpression of miR-15b-5p also inhibited cell growth and induced ERS and apoptosis. Moreover, re-expression of Rab1A rescued the miR-15b-5p-induced ERS, apoptosis, and growth inhibition in HCC cells. In vivo assays were further performed to testify them. Taken together, our data suggest that miR-15b-5p induces ERS, apoptosis, and growth inhibition by targeting and suppressing Rab1A, acting as a tumor suppressor gene in HCC. This finding suggests a novel relation among Rabs, miRNAs, and apoptosis.
在人类肝细胞癌（HCC）中，微小RNA（miRNA）的异常表达通过靶向下游蛋白与肿瘤细胞的增殖、凋亡、侵袭和迁移相关。据报道，HCC组织中miR-15b水平升高；然而，它们与HCC复发呈负相关。我们的目的是了解这种现象的原因。我们使用逆转录-聚合酶链反应（RT-PCR）来检测HCC组织和HCC细胞系中miR-15b-5p的表达。我们的结果与报道一致。通过生物信息学和荧光素酶报告基因检测，我们确定Rab1A是miR-15b-5p的一个新的直接靶点。用shRab1A抑制Rab1A的功能也抑制了HCC细胞的生长，并诱导了内质网应激（ERS）和细胞凋亡。同样，通过过表达miR-15b-5p抑制Rab1A也抑制了细胞生长，并诱导了ERS和细胞凋亡。此外，Rab1A的重新表达挽救了miR-15b-5p诱导的HCC细胞中的ERS、细胞凋亡和生长抑制。进一步进行体内实验以验证这些结果。综上所述，我们的数据表明，miR-15b-5p通过靶向和抑制Rab1A诱导ERS、细胞凋亡和生长抑制，在HCC中作为一种肿瘤抑制基因发挥作用。这一发现揭示了Rabs、miRNAs和细胞凋亡之间的一种新关系。
