Downregulation of microRNAs miR-1,-206 and-29 stabilizes PAX3 and CCND2 expression in rhabdomyosarcoma
Downregulation of microRNAs miR-1,-206 and-29 stabilizes PAX3 and CCND2 expression in rhabdomyosarcoma
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DOI：
10.1038/labinvest.2012.10
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发表时间：
2012-04-01
影响因子：
5
通讯作者：
Subramanian, Subbaya
中科院分区：
文献类型：
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作者：
Li, Lihua;Saryer, Aaron L.;Subramanian, Subbaya
PAX3和细胞增殖基因水平升高是横纹肌肉瘤（RMS）的特征。我们假设这些基因水平的增加是由于特定mirna的下调而稳定的。在这项研究中，我们发现miR-1、-206和-29的下调可以稳定PAX3和CCND2在胚胎型（ERMS）和肺泡型（ARMS） RMS中的表达。在ERMS细胞系JR1中异位表达miR-1和206可显著下调PAX3蛋白的表达，而在ARMS细胞系Rh30中过表达这些mirna对PAX3蛋白水平没有影响。在ARMS中，PAX3与fox01形成融合转录物，融合转录物中PAX3 3'UTR的缺失表明PAX3的致癌机制逃避了mirna介导的PAX3调控。此外，我们发现miR-1、-206和-29可以调节细胞周期基因CCND2的表达。除了CCND2， miR-29还靶向另一种细胞周期调节因子E2F7。细胞功能分析显示，过表达miR-29下调这些细胞周期基因的表达，诱导部分G1阻滞，导致细胞增殖下降。综上所述，我们的数据表明，RMS状态是通过解除多个miRNA及其靶基因的调控而稳定的，这支持了这些miRNA的肿瘤抑制作用。实验室调查（2012）92,571-583；doi: 10.1038 / labinvest.2012.10;2012年2月13日在线发布
Elevated levels of PAX3 and cell proliferation genes are characteristic features of rhabdomyosarcoma (RMS). We hypothesize that the increased levels of these genes are stabilized due to downregulation of specific miRNAs. In this study, we show that downregulation of miR-1, -206 and -29 stabilizes the expression of PAX3 and CCND2 in both embryonal (ERMS) and alveolar (ARMS) RMS types. Ectopic expression of miR-1 and 206 in JR1, an ERMS cell line, show significant downregulation of PAX3 protein expression, whereas overexpression of these miRNAs in Rh30, an ARMS cell line, did not show any effect in PAX3 protein levels. In ARMS, PAX3 forms a fusion transcript with FOXO1 and the resultant loss of PAX3 3'UTR in the fusion transcript indicate an oncogenic mechanism to evade miRNA-mediated regulation of PAX3. Further, we show that miR-1, -206 and -29 can regulate the expression of CCND2, a cell cycle gene. In addition to CCND2, miR-29 also targets E2F7, another cell cycle regulator. Cell function analysis shows that overexpression of miR-29 downregulates the expression of these cell cycle genes, induces partial G1 arrest leading to decreased cell proliferation. Taken together our data suggest that the RMS state is stabilized by the deregulation of multiple miRNAs and their target genes, supporting a tumor suppressor role for these miRNA. Laboratory Investigation (2012) 92, 571-583; doi:10.1038/labinvest.2012.10; published online 13 February 2012