MicroRNA Let-7a与p53基因在肺癌中表达的相关性

The Study on the Correlation between MicroRNA Let-7a and P53 in Lung Cancer

目的探讨各种不同病理类型肺癌P53基因及其蛋白与Let-7a基因的表达水平的关系及意义.方法用实时荧光定量PCR检测肺腺癌、肺鳞癌及小细胞肺癌和癌旁组织以及体外培养的肺癌细胞株A549中P53及Let-7a的基因表达,用Western Blot检测相应的P53蛋白.结果 Let-7a、P53在癌组织中的表达量均低于正常组织中表达量,差异有统计学意义. P53基因表达量与Let-7a基因表达量呈正相关关系(相关系数为0.963,P<0.001).各类型肺癌组织及肺癌细胞株A549中P53蛋白的表达水平差异不大(P>0.05),但二者均显著低于癌旁组织中的P53蛋白水平,与基因表达情况一致(t=6.488,P<0.001).结论 P53与Let-7a基因的表达在肺癌中均降低,且呈正相关关系,推测P53可能参与调控let-7a基因的表达,从而抑制癌细胞的增长.

Objective To study the relationship between the expression of Let-7 a and the expression of P53 and it’s protein in different pathological types of lung cancer tissues. Methods The specimens of adenocarcinoma,squamous carcinoma,small cell lung cancer and adjacent normal tissues were collected. Real-time fluorescence quantitative PCR was used to detect the expression of Let-7 a and P53 in different lung cancer tissues. And the P53 protein expression of the specimens of lung cancer,adjacent normal tissues and Lung cancer cell line A549 in vitro were detected by Western Blot. Results The expression of Let-7 a and P53 in cancer tissues was lower than that in normal tissues. There was a significant correlation between the expression of P53 gene and the expression of Let-7 a gene（the correlation coefficient was 0.963,P 〈 0.001）. The level of the expression of P53 protein in all types of lung cancer tissues and lung cancer cell lines was not significant（P 〉 0.05）. But the two protein levels were significantly lower than those in the adjacent tissues, which was consistent with the gene expression（t = 6.488, P 〈 0.001）. The P 53 levels were significantly different from those in the adjacent tissues. Conclusion The expression of P53 and Let-7 a gene is decreased in lung cancer and has a positive correlation. It is presumed that P53 may participate in the regulation of the expression of Let-7 a gene, thus inhibiting the growth of cancer cells.