支气管上皮增生病变FHIT和p53基因检测

Detection of FHIT gene and p53 gene in bronchial hyperplastic epithelial lesions

目的检测和分析FHIT基因杂合性缺失/微卫星不稳定(LOH/MI)和p53突变在肺癌和肺炎性病变(简称肺炎)的支气管上皮增生病变中是否存在差异。方法采用PCR银染技术结合二核苷酸(CA)n重复序列及PCR-SSCP-DNA测序法分别检测FHITLOH/MI和p53突变。采用免疫组化法检测FHIT和p53表达。结果FHITLOH/MI在肺癌组的鳞状上皮化生病变和轻-中度非典型增生病变分别为53.8%和70%,均明显大于肺炎性病变组的相应增生病变12.5%和18.2%,差异显著(P<0.05)。p53突变率在肺癌组和肺炎组的各级增生病变比较差异不显著(P>0.05)。结论FHITLOH/MI在肺癌组支气管上皮各级增生病变明显高于肺炎组,为其作为判断癌前病变的检测指标提供了实验依据。在肺癌前病变中FHIT基因LOH/MI同p53基因突变无关,是发生频率更高、更早的基因事件。

Objective To provide potential biomarkers for early diagonosis of truly bronchial preneoplastic lesions by detection and analysis of FHIT and p53 gene and its expression in bronchial preinvasive lesions from the operative specimen with lung cancer and lung inflammatory lesions. Methods By using PCR-denaturing polyacrylamide gel electrophoresis-silver staining, the loss of heterozygosity （LOH） and microsatellite instability （MI） in FHIT gene were examined. The expression of FHIT was detected immunohistochemicaUy. Results The rate of LOH/MI of FHIT in squamous metaplasia and mild-moderate dysplasia obtained from patients with SCC（53.8% and 70% respectively） was statistically （ P 〈 0.05） greater than that of matched lesions from patients with lung inflammatory lesions （ 12.5% and 18.2% ）. No significant difference in p53 mutations was observed between bronchial hyperplasia from lung cancer group and that from lung inflammatory lesions group（ P = 1.000）. Conclusions These results suggest that FHIT can be used as a molecular marker to identify ＂genuine＂ preneoplastic conditions. FHIT LOH/MI which occur independently in p53 mutions seems to be an earlier and more frequent molecular event in the transforming bronchial epithelium.