食管癌前细胞DNA含量及多基因表达的定量检测

Quantitive detection of multi-gene expressions and DNA content in the precancerous cells of esophageal carcinoma

目的 探讨食管癌高发区人群食管上皮癌变过程中的早期分子改变及早期癌变机理。方法 自食管癌高发区采集食管黏膜上皮细胞 ,碘化丙啶 (propidiumlodide ,PI)染色进行DNA含量及倍体测定 ;对各基因蛋白进行间接免疫荧光标记 ,采用流式细胞仪 (flowcytometry,FCM)进行定量检测。结果 DNA含量在癌形成时明显增高 ,二倍体细胞显著减少 ,而异倍体细胞明显增多 ,在癌细胞组异倍体率为 84.2 % ;同时p5 3蛋白有明显积聚 ,而抑癌基因p16有明显缺失。在癌细胞组p5 3及cyclinD1蛋白表达的阳性率均为 10 0 % (5 /5、6 /6 )。结论 在癌形成早期 ,DNA含量及异倍体率增加 ,癌基因cyclinD1表达增高 ,抑癌基因p16缺失及p5 3蛋白积聚。食管上皮癌形成时已有多个分子事件发生。

Objective To explore the molecular events and mechanism in the carcinogenesis of esophageal epithelium in the high incidence area of esophageal carcinoma. Methods Epithelial cells collected from the high incidence area of esophageal carcinoma were used to detect DNA content and ploidy by propidium iodide(PI)stain. The expressions of p53, p16 and cyclin D1 were stained by indirect immunofluorescence of fluorescein isothiocyanate(FITC), which were detected by flow cytometry(FCM). Results During the process of carcinogenesis, DNA content increased significantly. The diploid cells decreased while heteroploid cells increased sharply, with a heteroploiy rate of 84.2%. At the same time, the p53 protein accumulated and p16 was deleted. The positive rates of p53 and oncogene cyclin D1 were both 100%(5/5, 6/6)in the cancer group.Conclusion In the early carcinogenesis of esophageal epithelium, DNA content and heteroploidy rates increase with tumor suppressor gene p16 deletion and p53 protein accumulation while oncogene cyclin D1 is overexpressed. Multiple molecular events have already occurred when esophageal carcinoma develops.