Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan.
Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan; Center for Gastrointestinal Research, Center for Translational Genomics and Oncology, Baylor Scott & White Research Institute and Charles A Sammons Cancer Center, Baylor University Medical Center, TX, USA.
Cancer Lett. 2019 Mar 1;444:127-135. doi: 10.1016/j.canlet.2018.12.009. Epub 2018 Dec 21.
Adenosine-to-inosine (A-to-I) RNA editing is a recently described epigenetic modification, which is believed to constitute a key oncogenic mechanism in human cancers. However, its functional role in cancer-associated fibroblasts (CAFs) within the tumor microenvironment (TME) and its clinical significance remains unclear. Herein, we systematically analyzed a large cohort of 627 colorectal cancer (CRC) specimens, and investigated the expression pattern of ADAR1 and its biological significance on the antizyme inhibitor 1 (AZIN1) RNA editing levels. Both ADAR1 expression and AZIN1 RNA editing levels were significantly elevated in CRC tissues vs. normal mucosa, and these findings correlated with the increased expression of mesenchymal markers, Vimentin (ρ = 0.44) and Fibroblast activation protein (ρ = 0.38). Intriguingly, ADAR1 expression was specifically upregulated in both cancer cells and fibroblasts from cancerous lesions. Conditioned medium from cancer cells led to induction of ADAR1 expression and activation of AZIN1 RNA editing in fibroblasts (p < 0.05). Additionally, edited AZIN1 enhanced the invasive potential of fibroblasts. In conclusion, we provide novel evidence that hyper-editing of AZIN1 enhances the invasive potential of CAFs within the TME in colon and is an important predictor of tumor invasiveness in CRC.
腺嘌呤到肌苷(A-to-I)RNA 编辑是一种最近描述的表观遗传修饰,被认为是人类癌症中的关键致癌机制。然而,其在肿瘤微环境(TME)中的癌症相关成纤维细胞(CAFs)中的功能作用及其临床意义尚不清楚。在此,我们系统地分析了 627 例结直肠癌(CRC)标本的大样本,研究了 ADAR1 的表达模式及其对抗酶抑制剂 1(AZIN1)RNA 编辑水平的生物学意义。ADAR1 的表达和 AZIN1 RNA 编辑水平在 CRC 组织与正常黏膜中均显著升高,并且这些发现与间充质标志物波形蛋白(ρ=0.44)和成纤维细胞激活蛋白(ρ=0.38)的表达增加相关。有趣的是,ADAR1 在癌细胞和癌灶中的成纤维细胞中均特异性地上调。癌细胞的条件培养基导致成纤维细胞中 ADAR1 的表达诱导和 AZIN1 RNA 编辑的激活(p<0.05)。此外,编辑后的 AZIN1 增强了成纤维细胞的侵袭潜力。总之,我们提供了新的证据,表明 AZIN1 的过度编辑增强了 TME 中 CAFs 的侵袭潜力,是 CRC 中肿瘤侵袭性的重要预测因子。