食管癌相关纤维细胞通过调控长链非编码RNA DNM3OS的表达介导食管癌细胞产生放疗抵抗性的分子机制研究

Increasing evidences have suggested cancer-associated fibroblasts (CAFs), as one major component of tumor microenvironment, were involved in tumor response to chemoradiotherapy. In our previous study, CAFs had been successfully isolated from tumor tissues of EC patients. By use of lncRNAs (long non-coding RNAs) PCR array, we found DNM3OS was highly expressed in esophageal cancer cell lines and in tumor tissues of EC patients, compared with in normal esophageal epithelial cell line and normal tissues, respectively. When the esophageal cancer cell lines KYSE-30 and KYSE-140 were co-cultured with CAFs, the expression of DNM3OS in caner cells was up-regulated with a 38.3163-fold and 39.2554-fold increase, respectively, suggesting CAFs had significant influences on DNM3OS expression. Inhibition of DNM3OS expression in KYSE-30 cells and in KYSE-140 cells increased irradiation-induced DNA double-strand break, while attenuated DNA repair. Based on the above findings, this study aimed to investigate the molecular mechanisms by which CAFs up-regulated the expression of DNM3OS in esophageal cancer cell lines and how DNM3OS regulated DNA damage response, leading to tumor radioresistance. Our study would for the first time investigate tumor microenvironment-attenuated tumor radioresponse from the viewpoint of non-coding RNAs and discover novel targets to reverse tumor radioresistance in esophageal carcinoma.

肿瘤相关纤维细胞作为肿瘤微环境的主要成员，与肿瘤的治疗敏感性密切相关。课题组前期通过原代培养的方法成功地分离了食管癌相关纤维细胞（cancer-associated fibroblasts，CAFs）。采用lncRNAs(长链非编码RNA)芯片筛选发现DNM3OS在食管癌细胞系及在食管癌组织中显著地高表达。且当食管癌细胞KYSE-30及KYSE-140与CAFs共培养48h后，DNM3OS的表达可分别升高39.2554倍及38.3163倍，。抑制DNM3OS的表达可显著地增加放疗引起的食管癌细胞双链DNA损伤作用，同时抑制DNA修复蛋白表达。本研究拟在前期工作的基础上进一步揭示CAFs对 DNM3OS表达的调控机制以及DNM3OS如何通过调控DNA损伤修复响应介导食管癌细胞产生放疗抵抗性。该研究将率先从非编码RNA的角度阐明肿瘤微环境的抗肿瘤机制，为逆转食管癌放疗抵抗性筛选新型的分子靶点。

肿瘤相关纤维细胞（cancer-associated fibroblasts，CAFs）作为肿瘤微环境的主要成员，与肿瘤的治疗敏感性密切相关。课题组前期通过原代培养的方法成功地分离了食管癌相关纤维细胞。采用lncRNAs(长链非编码RNA)芯片筛选发现DNM3OS在食管癌细胞系及在食管癌组织中显著地高表达。且当食管癌细胞KYSE-30及KYSE-140与CAFs共培养48h后，DNM3OS的表达可分别升高39.2554倍及38.3163倍。抑制DNM3OS的表达可显著地增加放疗引起的食管癌细胞双链DNA损伤作用，同时抑制DNA修复蛋白表达，从而增加食管癌细胞的放疗敏感性。此外，抑制DNM3OS的表达亦可逆转由CAFs介导的食管癌细胞放疗抵抗性，提示CAFs通过调控DNM3OS的表达介导食管癌细胞产生显著的放疗抵抗性。课题组进一步的研究显示CAFs通过激活食管癌细胞中PDGF/ PDGFR/FOXO1信号通路上调DNM3OS的表达。综上，本项目首次从非编码RNA 的角度揭示了肿瘤微环境对食管癌细胞放疗敏感性的调控作用及其影响机制，将为临床上如何增加食管癌患者的放疗疗效提供重要的理论基础和创新依据。