细胞周期蛋白25A在非小细胞肺癌中的表达及与Let-7关系

目的 明确细胞周期蛋白25A（CDC25A）在NSCLC组织中的表达及与临床病理特征的关系，并探讨其与miRNA let-7a1、let-7c表达的相关性。方法 收集53例肺组织手术标本，其中包括NSCLC组织44例，收集其癌组织和癌旁正常组织（病理证实），和良性肺疾病组织9例。免疫组化Elivision法检测CDC25A蛋白的表达；用Trizol法提取总RNA，采用荧光定量RT-PCR检测CDC25A mRNA的表达，加尾法荧光定量RT-PCR检测let-7a1和let-7c mRNA的表达。结果 CDC25A蛋白表达的阳性率在NSCLC组织明显高于癌旁正常组织和良性肺疾病组织（P<0.05）。NSCLC组织中CDC25A蛋白的表达与年龄、性别、病理类型、肿瘤分化程度、临床分期无关（P>0.05），与吸烟、淋巴结转移相关（P<0.05）。CDC25A mRNA在NSCLC组织中的表达量明显高于癌旁正常组织和良性肺疾病组织（F=6.33，P<0.05），在癌旁正常组织和良性肺疾病组织中表达无明显差异（P>0.05）。Pearson 相关分析显示CDC25A与let-7c在NSCLC组织和癌旁正常组织中表达均呈明显负相关（r 癌组织=-0.42，r 癌旁正常组织=-0.40），与let-7a1之间无明显相关。结论 CDC25A在NSCLC组织表达水平明显增高，且与let-7c表达呈明显负相关，推测CDC25A可能是let-7c的下游靶基因。

Expression of CDC25A in non-small cell lung cancer and its relationship with let-7 gene

Objective To investigate the expression of CDC25A in non- small cell lung cancer (NSCLC) tissues and explore its correlation with the clinicpathological features of the patients and the expressions of let-7a1 and let-7c. Methods We collected surgical specimens of pathologically confirmed NSCLC tissues and paired adjacent lung tissues from 44 patients and tissues of benign lung lesions from 9 patients. The expressions of CDC25A protein and mRNA in the tissues were detected by immunohistochemistry and fluorescence quantitative RT-PCR, respectively; the expressions of let-7a1 and let-7c mRNA were detected using tail-adding fluorescence quantitative RT-PCR. Results The positivity rate of CDC25A protein expression was significantly higher in NSCLC tissues than in the adjacent tissues and benign pulmonary lesions (P<0.05). CDC25A protein expression in NSCLC was not correlated with the patients' age, gender, pathological type, degree of tumor differentiation, or clinical stages (P>0.05), and was significantly correlated with smoking and lymph node metastasis (P<0.05). CDC25A mRNA expression was also significantly higher in NSCLC tissues than in the adjacent tissues and benign pulmonary lesions (F=6.33, P<0.05), and was similar between the latter two tissues (P>0.05). Pearson correlation analysis showed that CDC25A expression had a significant negative correlation with let-7c expression in both NSCLC tissues (r=-0.42) and adjacent lung tissues (r=-0.40) but was not correlated with let- 7a1 expression. Conclusion The expression level of CDC25A is significantly increased in NSCLC with a negative correlation with Let-7c expression, which identifies CDC25A as a possible downstream target gene of Let-7c.