乳腺癌组织抑癌基因PTEN的表达及其意义

EXPRESSION AND SIGNIFICANCE OF THE TUMOR SUPPRESSOR GENE PTEN IN BREAST CANCER

目的探讨PTEN基因在人乳腺癌组织的表达及其与临床病理参数的关系。方法采用免疫组织化学法和原位杂交法,对70例乳腺癌组织PTEN基因mRNA和蛋白表达进行分析。结果15例乳腺良性肿瘤均见PTENmRNA和蛋白表达,其阳性率为(100·0%15/15);70例乳腺癌组织中PTENmRNA和蛋白表达明显降低,阳性率分别为51·4%(36/70)和47·1%(33/70),与对照组比较差异有显著性(P<0·01);PTEN基因表达下调与乳腺癌的组织学分级,TNM分期和腋淋巴结转移有关,而与肿瘤的大小和ER、PR状况无关。乳腺癌PTENmRNA表达检测结果与PTEN蛋白相似。结论乳腺癌中存在PTEN基因表达异常,PTEN表达下调与乳腺癌的进展、转移关系密切。

Objective To investigate the expression of the tumor suppressor gene PTEN in human breast cancer and its relation to clinical pathologic parameters. Methods Formalin-fixed paraffin-embedded tissues from 70 cases of primary invasive breast cancer were evaluated for PTEN mRNA and protein expressions by in situ hybridization and immunohistochemical methods. The relationship between the expression of PTEN gene in human breast cancer and clinical pathologic parameters was analyzed. Results The positive rates of PTEN mRNA and protein expressions were 51.4% （36/70） and 47. 1% （33/70） respectively, in breast cancer, but 100% （15/15） in benign breast tumors, the difference being highly significant （P〈0. 01）. The reduced expression of PTEN was significantly correlated with histological grade, TNM staging and axillary lymph node status but not with tumor size, estrogen and progesterone receptors. Conclusion There may be abnornal expression of PTEN gene in breast cancer. Its reduced expression may show a close relationship to the development and metastasis of the cancer.