Genomics screen in transformed stem cells reveals RNASEH2A, PPAP2C, and ADARB1 as putative anticancer drug targets
Genomics screen in transformed stem cells reveals RNASEH2A, PPAP2C, and ADARB1 as putative anticancer drug targets
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DOI：
10.1158/1535-7163.mct-08-0636
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发表时间：
2009-01-01
影响因子：
5.7
通讯作者：
Boshoff, Chris
中科院分区：
文献类型：
--
作者：
Flanagan, James M.;Funes, Juan M.;Boshoff, Chris
自人类基因组测序以来，最近在癌症药物靶点发现方面的努力更多地集中在鉴定已知基因的新功能和开发更合适的肿瘤模型上。在本研究中，我们研究了在体外转化的人成体间充质干细胞（MSC），以确定新的候选癌症药物靶点，通过分析已知酶的转录谱相比，非转化MSC。将鉴定的酶与已发表的癌症基因表达数据集进行比较。令人惊讶的是，大多数上调的酶是已知的癌症药物靶点或在已知的药物途径内起作用。只有三种酶（RNASEH 2A，ADARB 1和PPAP 2C）是潜在的新靶点，它们在转化的MSC中上调，并在许多癌和肉瘤中表达。我们证实了在转化的MSC、转化的成纤维细胞和癌细胞系MCF 7、SK-LMS 1、MG 63和U2 OS中RNASEH 2A、PPAP 2C和ADARB 1的过表达。在功能测定中，我们表明RNASEH 2A的小干扰RNA敲除可抑制非贴壁依赖性生长，但不会改变癌细胞系、正常MSC或正常成纤维细胞的体外增殖。PPAP 2C的敲除损害了癌细胞系的锚定依赖性体外生长，并损害了原代MSC的体外生长，但不损害分化的人成纤维细胞。我们发现，敲低PPAP 2C通过延迟进入细胞周期的S期来降低细胞增殖，并且受p53的转录调控。这些体外数据验证了PPAP 2C和RNASEH 2A作为推定的癌症靶标，并支持这种用于鉴定新候选物的计算机模拟方法。[Mol癌症治疗2009;8（1）：249-60]
Since the sequencing of the human genome, recent efforts in cancer drug target discovery have focused more on the identification of novel functions of known genes and the development of more appropriate tumor models. In the present study, we investigated in vitro transformed human adult mesenchymal stem cells (MSC) to identify novel candidate cancer drug targets by analyzing the transcriptional profile of known enzymes compared with non-transformed MSC. The identified enzymes were compared with published cancer gene expression data sets. Surprisingly, the majority of up-regulated enzymes are already known cancer drug targets or act within known druggable pathways. Only three enzymes (RNASEH2A, ADARB1, and PPAP2C) are potentially novel targets that are up-regulated in transformed MSC and expressed in numerous carcinomas and sarcomas. We confirmed the overexpression of RNASEH2A, PPAP2C, and ADARB1 in transformed MSC, transformed fibroblasts, and cancer cell lines MCF7, SK-LMS1, MG63, and U2OS. In functional assays, we show that small interfering RNA knockdown of RNASEH2A inhibits anchorage-independent growth but does not alter in vitro proliferation of cancer cell lines, normal MSC, or normal fibroblasts. Knockdown of PPAP2C impaired anchorage-dependent in vitro growth of cancer cell lines and impaired the in vitro growth of primary MSC but not differentiated human fibroblasts. We show that the knockdown of PPAP2C decreases cell proliferation by delaying entry into S phase of the cell cycle and is transcriptionally regulated by p53. These in vitro data validate PPAP2C and RNASEH2A as putative cancer targets and endorse this in silico approach for identifying novel candidates. [Mol Cancer Ther 2009;8(1):249-60]