Table_1_Downregulated ARID1A by miR-185 Is Associated With Poor Prognosis and Adverse Outcomes in Colon Adenocarcinoma.docx

AT-rich interaction domain 1A (ARID1A) is a tumor suppressor gene that mutates in several cancer types, including breast cancer, ovarian cancer, and colorectal cancer (CRC). In colon adenocarcinoma (COAD), the low expression of ARID1A was reported but the molecular reason is unclear. We noticed that ARID1A low expression was associated with increased levels of miR-185 in the COAD. Therefore, this study aims to explore ncRNA-dependent mechanism that regulates ARID1A expression in COAD regarding miR-185. The expression of ARID1A was tested in COAD cell line under the effect of miR-185 mimics compared with inhibitor. The molecular features associated with loss of ARID1A and its association with tumor prognosis were analyzed using multi-platform data from The Cancer Genome Atlas (TCGA), and gene set enrichment analysis (GSEA) to identify potential signaling pathways associated with ARID1A alterations in colon cancer. Kaplan-Meier survival curve showed that a low level of ARID1A was closely related to low survival rate in patients with COAD. Results showed that inhibiting miR-185 expression in the COAD cell line significantly restored the expression of ARID1A. Further, the increased expression of ARID1A significantly improved the prolonged overall survival of COAD. We noticed that there is a possible relationship between ARID1A high expression and tumor microenvironment infiltrating immune cells. Furthermore, the increase of ARID1A in tumor cells enhanced the response of inflammatory chemokines. In conclusion, this study demonstrates that ARID1A is a direct target of miR-185 in COAD that regulates the immune modulations in the microenvironment of COAD.

富含AT相互作用结构域1A（AT-rich interaction domain 1A, ARID1A）是一种抑癌基因，可在乳腺癌、卵巢癌、结直肠癌（colorectal cancer, CRC）等多种癌症类型中发生突变。已有研究报道，结肠腺癌（colon adenocarcinoma, COAD）中存在ARID1A低表达现象，但其具体分子机制尚不明确。本研究观察到，COAD组织中ARID1A低表达与miR-185水平升高存在显著关联，因此本研究旨在围绕miR-185，探讨COAD中依赖非编码RNA（non-coding RNA, ncRNA）调控ARID1A表达的分子机制。本研究在COAD细胞系中分别采用miR-185模拟物（mimics）与抑制剂（inhibitor）处理，检测ARID1A的表达水平；同时借助癌症基因组图谱（The Cancer Genome Atlas, TCGA）多组学数据与基因集富集分析（gene set enrichment analysis, GSEA），分析ARID1A缺失相关的分子特征及其与肿瘤预后的关联，以鉴定结直肠癌中与ARID1A改变相关的潜在信号通路。Kaplan-Meier生存曲线分析结果显示，ARID1A低表达的COAD患者生存率显著降低。实验结果表明，在COAD细胞系中抑制miR-185的表达，可显著恢复ARID1A的表达水平；进一步研究发现，ARID1A高表达可显著延长COAD患者的总生存期。本研究还观察到，ARID1A高表达与肿瘤微环境免疫细胞浸润存在潜在关联；此外，肿瘤细胞中ARID1A表达上调可增强炎性趋化因子的应答反应。综上，本研究证实ARID1A是COAD中miR-185的直接靶标，其可调控COAD肿瘤微环境中的免疫调节过程。