PTPN12与非小细胞肺癌放射敏感性的关系研究

Effect of protein tyrosine phosphatase non-receptor type 12(PTPN12) downregulation on the radiosensitivity of non-small cell lung cancer

目的:探讨非小细胞肺癌(non-small cell lung cancer,NSCLC)组织中非受体型蛋白酪氨酸磷酸酶12(protein tyrosine phosphatase non-receptor type 12,PTPN12)表达与放疗疗效的关系,评估PTPN12基因下调与H1299细胞放射敏感性的关系。方法:回顾性分析2013年9月至2014年10月河北医科大学第四医院92例接受根治性放疗的NSCLC患者的临床资料,通过免疫组织化学方法检测肿瘤组织中PTPN12的表达,并分析其与患者放疗疗效的关系。通过shRNA-PTPN12干扰质粒转染H1299细胞,利用实时定量PCR技术及Western blot技术检测PTPN12在mRNA及蛋白水平的表达。通过克隆形成实验构建细胞生存曲线,评估PTPN12基因下调对H1299细胞放射敏感性的作用。结果:PTPN12低表达患者的放疗疗效明显优于高表达者(80.0%vs.57.1%,P=0.018)。多因素分析显示PTPN12表达是影响放疗疗效的唯一因素。构建shRNA-GFP及shRNA-PTPN12干扰质粒转染H1299细胞,获得稳定转染细胞株H1299-shGFP及H1299-shPTPN12。细胞生存曲线显示H1299-shGFP及H1299-shPTPN12细胞的D0、Dq、SF2值分别为3.02 Gy、3.41 Gy、0.94及1.81 Gy、2.40 Gy、0.72,具有显著性差异(P<0.05)。结论:PTPN12低表达与NSCLC患者的放疗疗效密切相关,而PTPN12基因下调能明显增加H1299细胞的放射敏感性。

Objective： To identify the relationship between the expression of protein tyrosine phosphatase non- receptor type 12（PTPN12） and radiotherapy effect in non-small cell lung cancer（NSCLC） tissues and to determine whether PTPN12 deficiency can sensitize lung cancer cells to irradiation. Methods： From September 2013 to October 2014, 92 NSCLC patients undergoing radiotherapy with or without platinum-based combination chemotherapy were analyzed retrospectively. Before the treatment, PTPN12 expression was detected through immunohistochemistry. After the completion of radiotherapy, the patients’ responses were assessed and radiotherapeutic efficacy analyzed. The human NSCLC cell line H1299 was infected with sh PTPN12 knockdown, and colony survival assay was analyzed after irradiation. Chi-square test was used to examine the correlation between PTPN12 expression and clinicopathological characteristics. Univariate analyses and Logistic regression test were used to analyze the relationship between clinicopathological characteristics and radiotherapeutic response. Results： Patients with low PTPN12 expression were more sensitive to radiotherapy than those with high PTPN12 expression（80.0% vs. 57.1%, P=0.018）. Multivariate analysis showed that PTPN12 expression was the only independent predictor of radiotherapeutic response in NSCLC. The H1299-sh PTPN12-knockdown cells were sensitive to irradiation.Conclusions： The results of the study indicated that downregulation of PTPN12 improved the radiosensitivity of NSCLC cells.