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micro RNAs(miRNAs)在参与癌症发生、发展过程中起着十分重要的作用.目前,miR-92b在结直肠癌中的作用及相关机制还未见报道.本研究探讨了miR-92b在结直肠癌发生发展中的功能及潜在机制.采用RT-qPCR方法发现,miR-92b在人结直肠癌临床样本中与癌旁组织相比显著高表达.通过结肠癌细胞株SW620稳转细胞及裸鼠皮下成瘤模型,发现过表达miR-92b可以显著促进细胞增殖及体内肿瘤生长.同时还发现miR-92b可以分泌形式存在于胞外及外周血中,提示miR-92b是一个具有分泌特性的micro RNA.在分子机理方面,c-MYC可通过调节miR-92b的启动子活性从而促进后者转录,并且c-MYC在结直肠癌组织样本中也存在高表达.进一步,通过在线预测、报告质粒活性检测及蛋白质印迹技术证实FBXW7是一个新的miR-92b靶基因.由于FBXW7已报道为c-MYC泛素降解过程中的关键泛素化连接酶之一,本研究结果提示结直肠癌中c-MYC、miR-92b及FBXW7三者间可能存在分子调节环路.综上所述,本研究为miR-92b在结直肠癌中的功能及机制提供了新的视角,并为miR-92b在结直肠癌早期诊断中的应用提供了新的参考.
The role of miR-92b in colorectal cancer and its related mechanisms have not been reported yet.In this study, we explored the role of miR-92b in the development of colorectal cancer.MicroRNAs (miRNAs) play an important role in the carcinogenesis and progression of cancer, The function and potential mechanism of carcinogenesis and development.RT-qPCR method was used to find that miR-92b was highly expressed in human colorectal cancer clinical specimens compared with adjacent non-cancerous tissues.With colon cancer cell line SW620, Subcutaneous tumorigenesis model found that over-expression of miR-92b can significantly promote cell proliferation and tumor growth in vivo.It was also found that miR-92b can be secreted in extracellular and peripheral blood, suggesting that miR-92b is a secreted micro In terms of molecular mechanism, c-MYC can promote the transcription of miR-92b by regulating the promoter activity of miR-92b, and c-MYC is also highly expressed in colorectal cancer tissue samples.Furthermore, by online prediction, the reporter plasmid Activity detection and Western blotting confirmed that FBXW7 is a new miR-92b target gene.Because FBXW7 has been reported as one of the key ubiquitin ligases in c-MYC ubiquitin degradation process, the present study suggests that colorectal cancer c-MYC, miR-92b and FBXW7 may provide a molecular regulatory loop.To sum up, this study provides a new perspective for the function and mechanism of miR-92b in colorectal cancer, and provides a new perspective for miR-92b It provides a new reference for the early diagnosis of colorectal cancer.