Cyclin-dependent kinase 1 expression is inhibited by p16INK4a at the post-transcriptional level through the microRNA pathway
Cyclin-dependent kinase 1 expression is inhibited by p16INK4a at the post-transcriptional level through the microRNA pathway
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DOI：
10.1038/onc.2010.570
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发表时间：
2011-04-01
期刊：
影响因子：
8
通讯作者：
Ffrench, M.
中科院分区：
文献类型：
--
作者：
Chien, W. W.;Domenech, C.;Ffrench, M.
p(16INK4a) 蛋白主要通过抑制 G1 期细胞周期蛋白依赖性激酶 (CDK) 4 和 6 的活性、随后的视网膜母细胞瘤蛋白 (pRb) 磷酸化和 E2F 转录因子释放来调节细胞周期进程。 p(16INK4a) 蛋白还可以抑制其他转录因子的活性，例如 c-myc、核因子-kappaB 和 c-Jun/AP1。在此，我们报告，在两种 p16(-/-)、pRb(WT) 和 p53(WT) 细胞系（MCF7 和 U87）中，p(16INK4a) 过表达会导致 CDK1 蛋白表达急剧下降。响应 p(16INK4a)，CDK1 蛋白合成速率降低、其蛋白半衰期不变、CDK1 mRNA 稳态水平和 mRNA 半衰期未降低，使我们可以假设 p(16INK4a) 可以在转录后水平调节 CDK1 表达。这种 CDK1 下调是由 CDK1 mRNA 的 30 个非翻译区 (30UTR) 介导的，如荧光素酶测定中的翻译抑制所示，并且与潜在调节 CDK1 的 microRNA (miRNA) 表达平衡的改变有关，TaqMan Human microRNA Array 进行了分析。通过单独的逆转录 qPCR 证实了 MCF7 细胞中 p16INK4a 诱导的两种 miRNA（以 miR-410 和 miR-650 为例）的表达。此外，我们通过荧光素酶测定显示了 miR-410 或 miR-650 与 CDK1-30UTR 的相互作用。内源性 CDK1 表达在 miRNA 过表达时降低，并在同时抑制时增加。 miR-410（而非 miR-650）的诱导可能与 pRb/E2F 途径相关。这些结果证明了 p(16INK4a) 对 CDK1 的转录后抑制。我们认为 p(16INK4a) 可能通过改变转录因子的功能平衡进而改变 miRNA 的表达平衡来调节基因表达。癌基因 (2011) 30, 1880-1891; doi：10.1038/onc。 2010.570； 2010 年 12 月 20 日在线发布
The p(16INK4a) protein regulates cell cycle progression mainly by inhibiting the activity of G1-phase cyclin-dependent kinases (CDKs) 4 and 6, the subsequent retinoblastoma protein (pRb) phosphorylation and E2F transcription factor release. The p(16INK4a) protein can also repress the activity of other transcription factors, such as c-myc, nuclear factor-kappaB and c-Jun/AP1. Here, we report that, in two p16(-/-), pRb(WT) and p53(WT) cell lines (MCF7 and U87), p(16INK4a) overexpression induces a dramatic decrease in CDK1 protein expression. In response to p(16INK4a), the decreased rate of CDK1 protein synthesis, its unchanged protein half- life, unreduced CDK1 mRNA steady- state levels and mRNA half- life allow us to hypothesize that p(16INK4a) could regulate CDK1 expression at the post- transcriptional level. This CDK1 downregulation is mediated by the 30-untranslated region (30UTR) of CDK1 mRNA as shown by translational inhibition in luciferase assays and is associated with a modified expression balance of microRNAs (miRNAs) that potentially regulate CDK1, analyzed by TaqMan Human microRNA Array. The p16INK4a-induced expression of two miRNAs (miR-410 and miR-650 chosen as an example) in MCF7 cells is confirmed by individual reverse transcriptionqPCR. Furthermore, we show the interaction of miR-410 or miR-650 with CDK1-30UTR by luciferase assays. Endogenous CDK1 expression decreases upon both miRNA overexpression and increases with their simultaneous inhibition. The induction of miR-410, but not miR-650 could be related to the pRb/ E2F pathway. These results demonstrate the post-transcriptional inhibition of CDK1 by p(16INK4a). We suggest that p(16INK4a) may regulate gene expression by modifying the functional equilibrium of transcription factors and consequently the expression balance of miRNAs. Oncogene (2011) 30, 1880-1891; doi: 10.1038/onc. 2010.570; published online 20 December 2010