Fendler Annika, Jung Monika, Stephan Carsten, Erbersdobler Andreas, Jung Klaus, Yousef George M
Department of Urology, Charité - University Hospital, Berlin, Germany ; Berlin Institute of Urologic Research, Berlin, Germany.
PLoS One. 2013 Nov 19;8(11):e80807. doi: 10.1371/journal.pone.0080807. eCollection 2013.
microRNAs (miRNAs) are small molecules that regulate gene expression posttranscriptionally. In a previous study, we identified miR-96 to be upregulated in prostate cancer specimens in comparison to normal adjacent tissue and to be an independent marker of biochemical relapse in a multivariate prediction model. Therefore, we investigated the functional role of miR-96 in prostate carcinogenesis. LNCaP and DU145 prostate cancer cells were transiently transfected with miR-96 precursors and phenotypic changes were analyzed. The miR-96 increased proliferation and impaired apoptosis induced by camptothecine in these cells. In silico target prediction analysis identified FOXO1 as potential pro-apoptotic miR-96 target. miR-96 was able to bind to both bindings sites in the FOXO1 3' UTR in a luciferase reporter gene assay. Overexpression of miR-96 in LNCaP cells resulted in a reduced FOXO1 expression. Overexpression of FOXO1 induced a strong apoptotic phenotype that was partially rescued by coexpression of miR-96. RT-qPCR and immunohistochemistry of 69 prostate cancer specimens revealed a downregulation of FOXO1 and an inverse correlation of miR-96 and FOXO1 protein expression. In conclusion, we show that miR-96 can regulate apoptosis in prostate cancer, by inhibiting the FOXO1 transcription factor.
微小RNA（miRNA）是一类在转录后水平调控基因表达的小分子。在之前的一项研究中，我们发现与相邻正常组织相比，miR-96在前列腺癌标本中表达上调，并且在多变量预测模型中是生化复发的独立标志物。因此，我们研究了miR-96在前列腺癌发生中的功能作用。用miR-96前体瞬时转染LNCaP和DU145前列腺癌细胞，并分析其表型变化。miR-96增加了这些细胞的增殖，并损害了喜树碱诱导的细胞凋亡。计算机靶标预测分析确定FOXO1是miR-96潜在的促凋亡靶标。在荧光素酶报告基因试验中，miR-96能够与FOXO1 3'UTR中的两个结合位点结合。miR-96在LNCaP细胞中的过表达导致FOXO1表达降低。FOXO1的过表达诱导了强烈的凋亡表型，miR-96的共表达部分挽救了这种表型。对69例前列腺癌标本进行的RT-qPCR和免疫组织化学分析显示FOXO1表达下调，且miR-96与FOXO1蛋白表达呈负相关。总之，我们表明miR-96可通过抑制FOXO1转录因子来调节前列腺癌中的细胞凋亡。
