LncRNA1233影响食管鳞癌放疗敏感性的机制研究

Radical radio-chemotherapy is the main strategy for local advanced esophageal squamous cell carcinoma(ESCC), radiation resistance is a critical factor in treatment failure and local recurrence, affecting the survival and prognosis of patients. For the first time, we found that LncRNA1233 was down regulated in radioresistant ESCC, suggesting that LncRNA1233 might be involved in ESCC with radiotherapy resistance. By bioinformatics analysis and pre-experiment, we found that Pin1 could be one of the key targets of LncRNA1233. What’s more, Pin1 could regulate p53 and inhibit the apoptosis of mutant p53 induced by radiotherapy. Accordingly, we propose that LncRNA1233 affects the radio-sensitivity of ESCC by regulating Pin1. We intends to establish cell and animal models and collect clinical samples, use overexpressing and silencing technique to test radio-sensitivity and apoptosis. Using RIP and RNA pull down experiments, we intend to verify the regulatory interaction in LncRNA1233 and Pin1, elucidate the regulatory mechanism of LncRNA1233 in radio-sensitivity. The solution of this problem will provide a new theoretical basis for esophageal cancer radiotherapy.

局部晚期食管鳞癌首选根治性放化疗，放疗抵抗是治疗失败和局部复发的重要原因，影响患者生存及预后。研究表明LncRNA参与调控肿瘤放疗敏感性。本课题组首次利用LncRNA测序发现，LncRNA1233在放疗抵抗的食管鳞癌组织中表达下调，提示其可能参与了食管鳞癌放疗抵抗。通过生物信息学分析及预实验筛选出Pin1可能为LncRNA1233的关键靶点。研究报道Pin1可稳定突变型p53的表达抑制凋亡，介导放疗抵抗。据此我们推测：LncRNA1233通过调控Pin1表达介导凋亡通路影响食管鳞癌的放疗敏感性。课题组拟收集临床标本、建立细胞和动物模型，采用过表达与沉默策略，检测放疗敏感性及凋亡通路的变化，结合拯救实验、RIP和RNA拉下实验，验证LncRNA1233和Pin1相互调控关系，阐明LncRNA1233在食管鳞癌放疗敏感性中的作用机制，为食管鳞癌放疗增敏提供新的理论依据。

研究表明LncRNA参与调控肿瘤放疗敏感性。本课题组构建了食管鳞癌放射抵抗株，通过克隆形成实验验证了其放疗抗性。同时利用食管鳞癌组织和抵抗细胞株进行转录组测序，发现LncRNA1233在放疗抵抗的食管鳞癌组织和放射抵抗细胞株内均表达下调，提示其可能参与食管鳞癌放疗抵抗。通过生物信息学分析并筛选出Pin1可能为LncRNA1233的靶点，发现在低表达LncRNA1233细胞内Pin1稳定高表达。采用过表达与沉默技术，在ECA109细胞中沉默LncRNA1233或在ECA109抵抗株中过表达LncRNA1233，可显著影响辐射后细胞凋亡和DNA损伤修复，进而改变细胞的放射敏感性。拯救实验证实，在沉默LncRNA1233的细胞中沉默Pin1能逆转放射抵抗，同时在过表达LncRNA1233的抵抗株中过表达Pin1能增加细胞的放射抵抗。荧光素酶报告基因发现转染lncRNA1233可以明显抑制野生型Pin1的荧光素酶活性，但对突变型Pin1则无影响，证明PIN1是lncRNA1233的靶基因。此外，我们建立动物模型验证了LncRNA1233在体内的放疗增敏作用。该课题阐明LncRNA1233在食管鳞癌放疗敏感性中的作用机制，为食管鳞癌放疗增敏提供新的理论依据。