PTENP1/miR-93/SOCS6通路抑制PI3K/Akt通路对HPV16+食管鳞癌干细胞放射敏感性的影响

Human papillomavirus(HPV) is related with prognosis of multiple tumors after radiotherapy, however，the mechanism is controversial. Our previous studies have found HPV16+ esophageal squmous cell carcinoma(ESCC) patients have worse prognosis, and the mechanism might be that HPV 16 could induce PI3K/Akt signaling pathway activation and increase cancer stem cell phenotype.But how HPV16 affects ESCC stem cell remains to be further studied. Pseudogene could regulate the expression of parent gene, and other target genes through competitive endogenous（ceRNA）. Our group have found overexpression of PTENP1 has different affect on PTEN in several ESCC cell lines, but PTENP1 could enhance the expression of suppressor of cytokine signaling 6 (SOCS6). Bioinformatics analysis indicate that PTENP1 and SOCS6 are ceRNA by combining with many miRNAs, such as miR-93.Furthermore, in HPV+cervical cancer, miR-93 increases significantly, and is related with ESCC cell proliferation and migration.Therefore, we hypothesize that PTENP1 can inhibit PI3K/Akt signaling pathway induced by HPV16 and regulate radiosensitization on esophageal squmous cell carcinoma stem cells by regulating SOCS6 through competitive binding with miR-93. In this project, we propose to illuminate the relation of PTENP1/miR-93/SOCS6 and HPV16+ ESCC radiosensitization and reverse radioresistance of HPV16+ ESCC stem cell .We hope this research could provide a new method for precise radiation medicine of HPV related ESCC radiosensitization.

HPV与多种肿瘤放疗预后相关，课题组发现HPV16激活PI3K/Akt通路、促进食管鳞癌（ESCC）干细胞表型致预后不良；HPV16+ ESCC干细胞特性尚待研究。假基因除调控亲本基因表达，还通过竞争性内源RNA（ceRNA）调控其他靶基因。我们亦发现PTENP1对ESCC细胞PTEN影响不一,但均提高Akt抑制因子SOCS6表达。分析表明PTENP1和SOCS6互为ceRNA，其相关的miR-93在HPV+宫颈癌高表达且促进ESCC增殖。推测PTENP1通过miR-93与SOCS6形成调控路径，阻断HPV16诱发的PI3K/Akt通路活化，影响HPV16+ ESCC干细胞放射敏感性。本项目基于ceRNA理论及前期研究，拟在肿瘤干细胞水平研究PTENP1/miR-93/SOCS6通路调控HPV16+ ESCC放射敏感性及PI3K/Akt通路介导机制，为HPV相关ESCC精准放射提供新思路。

食管鳞癌（ESCC）在我国发病率高，放疗同步铂类药物化疗是不可手术ESCC标准治疗模式，然而肿瘤的放射抵抗往往导致放疗失败。细胞因子信号抑制因子6（suppressor of cytokine signaling 6，SOCS6）具有抑制信号转导功能且在ESCC中低表达。本课题组前期研究发现人乳头瘤病毒（human papillomavirus，HPV）感染使ESCC细胞干细胞特性增强，进而放射抗性增强。本研究旨在探讨SOCS6对ESCC肿瘤生物学特性及HPV16+ ESCC放射敏感性的影响及作用机制。本课题收集本院ESCC患者术后肿瘤组织标本分析预后与SOCS6表达的关系，构建SOCS6过表达的ESCC与HPV16+ ESCC稳定转染株及SOCS6敲减的ESCC稳定转染株，检测细胞增殖、迁移、上皮间质转化、细胞周期与细胞凋亡、顺铂敏感性；X线照射细胞后行克隆形成实验检测细胞放射敏感性并检测DNA损伤修复相关蛋白表达、干细胞特性。在体验证SOCS6抑制ESCC生长并促进放射敏感性的功能。在HPV16+ ESCC及ESCC细胞中对SOCS6与c-KIT进行共定位、检测c-KIT泛素化水平及与SOCS6的结合能力、c-KIT下游PI3K/Akt信号的活性。实验结果证实ESCC组织中SOCS6低表达与患者不良预后有关；SOCS6可抑制ESCC细胞的增殖、迁移、EMT及肿瘤细胞干性，促进细胞凋亡并增强其对放射线的敏感性；SOCS6提高HPV16+ ESCC放射敏感性并降低肿瘤细胞干性；SOCS6与c-KIT受体直接作用促进其泛素化降解，抑制c-KIT/PI3K/Akt信号通路活性，从而增强ESCC和HPV16+ ESCC细胞放射敏感性。本项目的完成为改善ESCC放射敏感性提供新思路，为逆转HPV16+ESCC放射抵抗提供新依据。