结直肠腺瘤APC蛋白表达异常及DNA倍体分析

目的探讨结直肠腺瘤进展与APC(adenomatous polyposis coli)蛋白表达及DNA倍体的关系。方法应用免疫组织化学Elivision二步法检测APC的表达水平。采用流式细胞仪(FCM)进行DNA含量测定,分析APC表达和DNA倍体异常与腺瘤恶性程度的关系。结果①APC在正常黏膜、腺瘤、腺癌中的阳性率分别为81.8%、41.4%、23.5%,正常黏膜组APC阳性率高于腺瘤及腺癌组(P<0.05),腺瘤与腺癌组差异无统计学意义。4级腺瘤组APC阳性率分别为61.1%、40.8%、20.0%、18.8%,轻度非典型增生腺瘤组APC阳性率高于重度非典型增生及腺瘤癌变组(P<0.05)。②在正常黏膜、腺瘤、腺癌中异倍体率分别为0、42%、77%,依次升高,差异有统计学意义(P<0.05)。4级腺瘤组异倍体率分别为0、25%、70%、75%,重度非典型增生、癌变腺瘤组异倍体率均高于轻度非典型增生腺瘤组(P<0.05)。结论①APC在腺瘤、腺癌中的表达低于正常黏膜,APC的表达随着腺瘤非典型增生程度加重,有下降趋势。轻度非典型增生腺瘤APC阳性率高于重度非典型增生、癌变腺瘤。②正常黏膜→腺瘤→腺癌,异倍体率逐渐增加,且随着非典型增生程度加重,恶性度逐渐升高。③异倍体腺瘤APC表达低于二倍体腺瘤。提示DNA倍体异常、APC蛋白表达异常共同参与了结直肠腺瘤的进展。DNA倍体分析,结合APC蛋白表达检测可能作为临床判断腺瘤恶性程度、估价临床预后的一项客观指标。

Abnomal expression of adenomatous polyposis coli protein correlated to DNA ploidies

Objective To explore the correlation of adenomatous polyposis coli(APC) development with DNA ploidies.Methods Immunohistochemistric Elivision two-type method was used to determine APC expression level and flow cytometry to DNA contents,analysing APC expression and abnormality of DNA ploidies correlated with the malignant degree of APC.Results ①Positive rates of APC in normal mucosa,adenoma and adenocarcinoma were 81.8%,41.4% and 23.5%,respectively.APC positive rate was higher in normal mucosa than in adenoma and adenocarcinoma (P<0.05).There was no significant difference between adenoma and adenocarcinoma.Positive rates of the 4-grades of adenoma were 61.1%,40.8%,20.0% and 18.8%,respectively.APC positive rate was higher in mild atyptical hyperplasia adenoma than in serious one (P<0.05).②Heteroploidy rates in normal mucosa,adenoma and adenocarcinoma were 0,0.42% and 0.77% respectively and successively,and there was significant difference (P<0.05).Heteroploidy rates of 4 grades of ademona were 0,0.25%,70% and 75% respectively,and they were higher in serious atyptical hyperplasia and cancerated ademona than in mild atyptic adenoma(P<0.05).Conclusion ①APC positive rate is higher in mild atypical than in serious atypical hyperplasia and adenocarcinoma (P<0.05).②Ploidic rates grandually increase along with the disease developing: normal mucosa→adenoma→adenocarcinoma.③APC expression is lower in heteroploidy adenoma than in diploidy one.These indicate that abnormal DNA ploidies and abnormal APC expression are together involved in colorecal neoplasm development.DNA ploidy analysis combined with APC protein expression may be represented as the index to judge the malignant degree and prognosis of adenoma.