Department of Chemistry and Biochemistry, University of Notre Dame, 251 Nieuwland Science Hall, Notre Dame, Indiana 46556, USA.
J Proteome Res. 2012 Sep 7;11(9):4744-54. doi: 10.1021/pr300600r. Epub 2012 Aug 27.
The miR-143/-145 cluster is greatly reduced in several cancers, including colon cancer. Both miR-143 and miR-145 have been shown to possess antitumorigenic activity with involvement in various cancer-related events such as proliferation, invasion, and migration. As the deregulation of the miR-143/-145 cluster is implicated in tumorigenesis, we combined SILAC and microarray analyses to systematically interrogate the impact of miR-143/-145 on the colon cancer proteome and transcriptome. Using SILAC, we identified over 2000 proteins after reintroduction of miR-143 and miR-145, in the colon cancer cell line SW480, individually, and then, in concert. Our goal was to determine whether these microRNAs function individually or synergistically. The resulting regulated gene products showed evidence of both mRNA destabilization and translational inhibition with a bias toward the former mechanism of regulation. Numerous candidate targets were identified whose expression is attributable to an individual microRNA or whose regulation was more apparent following reintroduction of the miR-143/-145 cluster. In addition, several shared targets of miR-143 and miR-145 were identified. Overall, our results indicate that the summed effects of individually introduced microRNAs produce distinct molecular changes from the consequences of the assembled cluster. We conclude that there is a need to investigate both the individual and combined functional implications of a microRNA cluster.
miR-143/-145 簇在多种癌症中大大减少，包括结肠癌。miR-143 和 miR-145 都具有抗肿瘤活性，参与多种与癌症相关的事件，如增殖、侵袭和迁移。由于 miR-143/-145 簇的失调与肿瘤发生有关，我们结合 SILAC 和微阵列分析系统地研究了 miR-143/-145 对结肠癌蛋白质组和转录组的影响。使用 SILAC，我们在单独和协同重新引入 miR-143 和 miR-145 后，在结肠癌细胞系 SW480 中鉴定了超过 2000 种蛋白质。我们的目标是确定这些 microRNAs 是否单独或协同发挥作用。由此产生的受调控的基因产物显示出 mRNA 不稳定和翻译抑制的证据，前者是主要的调节机制。鉴定出了许多候选靶标，其表达归因于单个 microRNA，或者在重新引入 miR-143/-145 簇后，其调节更为明显。此外，还鉴定了 miR-143 和 miR-145 的几个共同靶标。总体而言，我们的结果表明，单独引入的 microRNAs 的总和效应产生的分子变化与组装簇的后果不同。我们得出结论，需要研究 microRNA 簇的个体和组合功能意义。
