Loss of ARID1A induces a stemness gene ALDH1A1 expression with histone acetylation in the malignant subtype of cholangiocarcinoma.
Loss of ARID1A induces a stemness gene ALDH1A1 expression with histone acetylation in the malignant subtype of cholangiocarcinoma.
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DOI：
10.1093/carcin/bgz179
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发表时间：
2020-07
期刊：
影响因子：
4.7
通讯作者：
J. Yoshino;Y. Akiyama;S. Shimada;Toshiro Ogura;K. Ogawa;H. Ono;Y. Mitsunori;D. Ban;A. Kudo
中科院分区：
文献类型：
--
作者：
J. Yoshino;Y. Akiyama;S. Shimada;Toshiro Ogura;K. Ogawa;H. Ono;Y. Mitsunori;D. Ban;A. Kudo
近年来，基因组学研究发现，人肝内胆管细胞癌（intrahepatic cholangiocarcinoma，ICC）是一种以染色质重塑基因ARID 1A突变为特征的恶性肿瘤，但其生物学和分子生物学功能尚不清楚。我们在此研究了人类ICC中ARID 1A缺陷的临床和生物学意义。免疫组化分析表明，ARID 1A的丢失是ICC患者总生存率的独立预后因素（P = 0.023）。我们通过使用来自两个人胆管癌细胞系的CRISPR/Cas9系统建立了ARID 1A敲除（KO）细胞。ARID 1A-KO细胞表现出显著增强的迁移、侵袭和球体形成活性。基因芯片分析显示，ALDH 1A 1，一个干细胞基因，是ARID 1A-KO细胞中最显着升高的基因。此外，作为癌症干细胞标志的ALDH酶活性在KO细胞中显著高。ARID 1A和组蛋白去乙酰化酶1直接募集到胆管癌细胞中的ALDH 1A表达检测不到ALDH 1A的启动子区域。ARID 1A基因表达下调后，ALDH 1A 1启动子区组蛋白H3 K27乙酰化水平明显升高（P < 0.01）。在临床上，ARID 1A和ALDH 1A的表达在原发性ICC中也呈负相关（P = 0.018），并且ARID 1A阴性和ALDH 1A 1阳性的ICC比仅ARID 1A阴性的病例显示更差的预后（P = 0.002）。总之，ARID 1A可能通过降低组蛋白H3 K27乙酰化水平下调ALDH 1A 1表达，在ICC中发挥肿瘤抑制因子的作用。我们的研究为开发ARID 1A阴性ICC的新表观遗传方法提供了基础。
Genomic analyses have recently discovered the malignant subtype of human intrahepatic cholangiocarcinoma (ICC) characterized by frequent mutations of chromatin remodeling gene ARID1A, however, the biological and molecular functions still remain obscure. We here examined the clinical and biological significances of ARID1A deficiency in human ICC. Immunohistochemical analysis demonstrated that loss of ARID1A was an independent prognostic factor for overall survival of ICC patients (P = 0.023). We established ARID1A-knockout (KO) cells by using the CRISPR/Cas9 system from two human cholangiocarcinoma cell lines. ARID1A-KO cells exhibited significantly enhanced migration, invasion, and sphere formation activity. Microarray analysis revealed that ALDH1A1, a stemness gene, was the most significantly elevated genes in ARID1A-KO cells. In addition, ALDH enzymatic activity as a hallmark of cancer stem cells was markedly high in the KO cells. ARID1A and histone deacetylase 1 were directly recruited to the ALDH1A1 promoter region in cholangiocarcinoma cells with undetectable ALDH1A expression by chromatin immunoprecipitation assay. The histone H3K27 acetylation level at the ALDH1A1 promoter region was increased in cells when ARID1A was disrupted (P < 0.01). Clinically, inverse correlation between ARID1A and ALDH1A expression was also identified in primary ICC (P = 0.018), and ARID1A-negative and ALDH1A1-positve ICCs showed worse prognosis than only ARID1A-negative cases (P = 0.002). In conclusion, ARID1A may function as a tumor suppressor in ICC through transcriptional downregulation of ALDH1A1 expression with decreasing histone H3K27 acetylation. Our studies provide the basis for the development of new epigenetic approaches to ARID1A-negative ICC.