二甲基苯蒽诱导大鼠乳腺癌微卫星不稳定性与cyclin D1、P53表达的意义

Significance of microsatellite instability and expressions of cyclin D1 and P53 proteins in breast carcinoma induced by DMBA in rats

目的 探讨大鼠乳腺癌发生中微卫星不稳定性发生情况及其cyclinD1、P5 3蛋白表达。方法 雌性Wistar大鼠 3 0只 ,利用二甲基苯蒽 2 0 0mg/kg灌胃 ,复制大鼠乳腺癌动物模型 ,应用PCR技术检测大鼠 8个微卫星位点D1Mitl4、D1Mgh2、D1Mgh6、D3Mit3、D3Mgh9、D5Mitll、D5Mgh5及D7Mgh1微卫星不稳定性 (MSI)发生情况 ;用SP免疫组织化学技术检测cyclinD1、P5 3在乳腺癌中的表达。结果 2 7例乳腺癌中有 2例发生MSI ,9/ 2 7例P5 3表达阳性 ,12 / 2 7例cyclinD1表达阳性 ,且与组织学分级及肿瘤大小有关。结论 MSI不是大鼠乳腺癌发生中常见现象 ,cyclinD1过表达是乳腺癌发生的早期事件 ,而P5

Objective To investigate the significance of microsatellite instability(MSI) and expressions of cyclin D1 and P53 in 7,12 dimethylbenz(a)anthracene (DMBA) induced breast carcinoma in rats. Methods Animal model of rat breast carcinoma was duplicated in 30 female Wistar rats by gastric irrigation of DMBA at the dose of 200 mg/kg. Eight microsatellite loci(D1Mitl4, D1Mgh2, D1Mgh6, D3Mit3, D3Mgh9, D5Mitll, D5Mgh5 and D7Mgh1) were selected for the examination of MSI of breast carcinoma by PCR analysis. S P immunohistochemical staining was used to study the expressions of cyclin D1 and P53 in DMBA induced breast carcinoma in rats. Results Of the 27 cases of breast carcinoma, there were 2 cases of MSI at 8 loci, 9 cases with P53 overexpression and 12 cases with cyclin D1 overexpression. All these were associated with histological grading. Conclusion MSI is infrequent in breast carcinogenesis in rats. Cyclin D1 overexpression may be the early event but P53 protein overexpression may be the late event in breast carcinoma.