Identification of SCN3B as a novel p53-inducible proapoptotic gene
Identification of SCN3B as a novel p53-inducible proapoptotic gene
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DOI：
10.1038/sj.onc.1208067
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发表时间：
2004-10-14
期刊：
影响因子：
8
通讯作者：
Tokino, T
中科院分区：
文献类型：
--
作者：
Adachi, K;Toyota, M;Tokino, T
肿瘤抑制因子p53是一种转录因子，在细胞应激反应中诱导生长停滞和/或细胞凋亡。为了鉴定新的p53诱导基因，我们通过cDNA代表性差异分析比较了正常小鼠胚胎成纤维细胞（MEFs）和p53缺失细胞中基因的表达。我们在这里报道了内源性钠通道亚基β 3 （SCN3B）在小鼠胚胎成纤维细胞中以p53依赖的方式通过DNA损伤上调表达。此外，我们发现SCN3B水平在人类癌细胞系中被DNA损伤剂和p53的过表达上调，但p63或p73的过表达不显著。此外，我们在第一个外显子上游（RE1）和第三个内含子上游（RE2）确定了两个假定的p53结合位点。通过染色质免疫沉淀评估，p53蛋白可以直接与体内推定的p53结合位点相互作用。报告基因分析显示，这两个p53结合位点是功能性应答元件。SCN3B蛋白似乎定位于内质网（ER）。将SCN3B基因导入T98G和Saos2细胞可有效抑制集落形成。此外，我们发现腺病毒介导的SCN3B转移与抗癌药物联合使用可诱导细胞凋亡。本研究结果表明，SCN3B介导p53依赖性凋亡通路，可能是基因治疗联合抗癌药物的候选者。
Tumor suppressor p53 is a transcription factor that induces growth arrest and/or apoptosis in response to cellular stress. To identify novel p53-inducible genes, we compared the expression of genes in normal mouse embryo fibroblasts (MEFs) to p53-null cells by cDNA representational difference analysis. We report here that expression of endogenous sodium channel subunit beta 3 (SCN3B) is upregulated in mouse embryonic fibroblasts by DNA damage in a p53-dependent manner. In addition, we found that SCN3B levels are upregulated in human cancer cell lines by DNA damaging agents, as well as by overexpression of p53, but not significantly by p63 or p73. Furthermore, we identified two putative p53-binding sites upstream of the first exon (RE1) and in the third intron (RE2). The p53 protein can directly interact with the putative p53-binding sites in vivo, as assessed by chromatin immunoprecipitation. A reporter gene assay revealed that these two p53-binding sites are functional response elements. The SCN3B protein appears to be localized to the endoplasmic reticulum (ER). Introduction of the SCN3B gene into T98G and Saos2 cells potently suppressed colony formation. Furthermore, we found that adenovirus-mediated transfer of SCN3B induced apoptosis when combined with anticancer agents. The results presented here suggest that SCN3B mediates a p53-dependent apoptotic pathway and may be a candidate for gene therapy combined with anticancer drugs.