小细胞肺癌干细胞和肿瘤组织中HIF-1α和HIF-2α的表达及意义

摘要

目的 观察小细胞肺癌干细胞和肿瘤组织中HIF-1α和HIF-2α的表达,并探讨其临床意义.方法 采用干细胞无血清培养技术富集小细胞肺癌细胞系H446第3代肿瘤球细胞作为肿瘤干细胞;实时荧光定量PCR法检测H446干细胞中HIF-1α和HIF-2α mRNA的表达;免疫荧光法检测H446干细胞中HIF-1 α和HIF-2α蛋白表达;免疫组化SP法检测小细胞肺癌组织中HIF-1α和HIF-2α蛋白表达.结果 小细胞肺癌干细胞HIF-2α mRNA表达上调(P＜0.05),而HIF-1αmRNA表达下调(P＜0.05);小细胞肺癌干细胞中HIF-2α蛋白呈阳性,而HIF-1α蛋白呈阴性;小细胞肺癌组织中HIF-1α的阳性率为46.7％(28/60),HIF-2α阳性率为25％(15/60).相关分析结果显示HIF-2α与小细胞肺癌干细胞标志物uPAR呈正相关且两者共同表达于小细胞肺癌坏死组织周围区域;HIF-2α与小细胞肺癌肿瘤直径和远处转移有关(P＜0.05),而HIF-1α与患者年龄、性别、肿瘤直径、淋巴结转移、胸膜侵袭和远处转移无关(P＞0.05).结论 HIF-2α在小细胞肺癌干细胞中表达上调且与小细胞肺癌干细胞标志物uPAR呈正相关,与小细胞肺癌肿瘤直径和远处转移相关,提示HIF-2α表达可能与小细胞肺癌干细胞样特征有关.%Purpose To observe the expression of HIF-1αand HIF-2α in tumor stem cells and tumor tissues of small cell lung cancer (SCLC) and to explore their clinical significance.Methods The defined serum-free culture was used to enrich the third passage tumor spheres cells from H446 as the tumor stem cells.Real-time PCR was performed to determine the mR-NA expression level of HIF-1α and HIF-2α in H446 tumor stem cells.Immunofluorescence staining was performed to determine the protein expression level of HIF-1α and HIF-2α in H446 tumor stem cells.Immunohistochemistry SP method was used to detect the expression of HIF-1α and HIF-2αt in SCLC tissues.Results The mRNA expression level of HIF-2α was up-regulated in tumor stem cells.However,the mRNA expression level of HIF-1 α was down-regulated in tumor stem cells (P ＜ 0.05).The expression of HIF-2α protein was positive in tumor stem cells.In contrast,HIF-1α protein was negative in tumor stem cells.In SCLC tissues,the positive rate of HIF-1α was 46.7％ (28/60),and the positive rate of HIF-2α was 25％ (15/60).Correlation analysis showed that HIF-2α was positively correlated with SCLC stem cell marker uPAR,and they co-localized around necrotic regions.The expression of HIF-2α was closely related to tumor diameter and distant metastasis.In contrast,the expression of HIF-1α had no relationship with age,sexy,tumor size,lymph metastasis,pleural invasion and distant metastasis (P ＞ 0.05).Conclusion HIF-2α is up-regulated in SCLC stem cells and positively correlated with SCLC stem cell marker uPAR,which are associated with the tumor diameter and distant metastasis of SCLC patients,suggesting that the expression of HIF-2α may be related to SCLC stem-like characteristics.