Epigenetics, Micro As, and Carcinogenesis: Functional Role of MicroRNA-137 in Uveal Melanoma
Epigenetics, Micro As, and Carcinogenesis: Functional Role of MicroRNA-137 in Uveal Melanoma
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DOI：
10.1167/iovs.10-5272
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发表时间：
2011-03-01
影响因子：
4.4
通讯作者：
Tu, LiLi
中科院分区：
文献类型：
--
作者：
Chen, Xiaoyan;Wang, Jiao;Tu, LiLi
目的. microRNAs（miRNAs）可以通过作为癌基因或肿瘤抑制基因参与肿瘤发生。作者先前对miR-34 a的研究表明，miRNA可以影响葡萄膜黑色素瘤细胞的生长。在这项研究中，他们研究了miR-137在葡萄膜黑色素瘤发病机制中的作用。采用实时荧光定量RT-PCR方法检测葡萄膜黑素细胞和葡萄膜黑色素瘤细胞系中miR-137的表达水平。MTS法检测细胞增殖，流式细胞仪检测细胞周期。通过生物信息学预测miR-137的靶基因，并使用荧光素酶报告基因测定进行确认。Western blot分析MITF、CDK 6和细胞周期调控蛋白的表达。使用实时RT-PCR方法测试表观遗传药物增加miR-137表达的能力。miR-137在葡萄膜黑色素瘤细胞系中的表达低于葡萄膜黑色素细胞。将miR-137异位转染到葡萄膜黑色素瘤细胞中诱导G1细胞周期停滞，导致细胞生长显著降低。miR-137的过表达下调MITE，一种具有致癌活性的转录因子。此外，miR-137的引入下调了致癌酪氨酸激酶蛋白受体c-Met和细胞周期相关蛋白，包括CDK 6。增加miR-137表达水平的一种途径是通过用DNA羟甲基化剂5-氮杂-2 '-脱氧胞苷和组蛋白脱乙酰酶抑制剂阿司他汀A处理。结果表明，miR-137可通过下调靶基因MITF和CDK 6的表达，抑制恶性黑色素瘤细胞的增殖。miR-137可能在葡萄膜黑色素瘤肿瘤发生过程中表观遗传学沉默。（Invest Opbthalmol维斯科学。201152：1193-1199）DOI：10.1167/iovs.10-5272
PURPOSE. MicroRNAs (miRNAs) can contribute to tumorigenesis by acting as either oncogenes or tumor suppressor The authors' previous studies on miR-34a showed that miRNA can influence the growth of uveal melanoma cells. In this study, they investigated the role of miR-137 in the pathogenesis of uveal melanoma.METHODS. Real-time RT-PCR was used to screen the expression levels of miR-137 in uveal melanocytes and uveal melanoma cell lines. Cell proliferation was examined by MTS assay and cell cycle was analyzed by flow cytometry. The target genes of miR-137 were predicted by bioinformatics and confirmed using a luciferase reporter assay. The expression of MITF, CDK6, and cell cycle regulatory proteins was determined by Western blot analysis. The ability to increase miR-137 expression by epigenetic drugs was tested using real-time RT-PCR.RESULTS. miR-137 expression was lower in uveal melanoma cell lines than in uveal melanocytes. Ectopic transfection of miR-137 into uveal melanoma cells induced G1 cell cycle arrest, leading to a significant decrease in cell growth. Overexpression of miR-137 downregulated MITE, a transcription factor with oncogenic activity. Moreover, the introduction of miR-137 downregulated the oncogenic tyrosine kinase protein receptor c-Met and cell cycle-related proteins, including CDK6. One avenue to increase the expression levels of miR-137 was through treatment with a DNA.hypornethylating agent, 5-aza-2'-deoxycytidine, and a histone deacetylase inhibitor, trichosta tatin A.CONCLUSIONS. The results showed that miR-137 can act as a tumor suppressor in weal melanoma cell proliferation through downregulation of the targets MITF and CDK6. miR-137 may be epigenetically silenced during uveal melanoma tumorigenesis. (Invest Opbthalmol Vis Sci. 201152:1193-1199) DOI:10.1167/iovs.10-5272