Studies on the Expression of Drug-resistance-associated Genes in Breast Carcinoma Tissues

[ Objective ] To explore the expression of glutathione-S-transferases-π(GST-π), multidrug resistance-associated protein (MRP), lung resistance protein (LRP) and P-glycoprotein (P-gp) in breast carcinoma tissues and to analyze the relationship of the above drug-resistance-associated genes with the levels of estrogen ( ER) , progesterone (PR), C-erbB2, and P53 and lymph node metastasis. [Methods] One hundred and three surgical tissue samples from the patients pathologically confirmed as breast carcinoma were collected. None of the patients had received chemotherapy before surgery. The expression of GST-π, MRP, LRP and P-gp was detected by immunohistochemical method. And then the correlation of the four drug-resistance-associated genes with ER, PR, C-erbB2 and P53, which are related to the prognosis of breast carcinoma, was analyzed. Meanwhile, the patients were divided into the group with lymph node metastasis and the other group without metastasis, and the expression of 4 genes in both groups was treated with Chi-square test. [Results] The expression rate of GST-π, MRP, LRP and P-gp was 56.3% , 16.7%, 72.8% and 57.1% respectively, characterized by low-level expression with the positive cells less than 25% . The difference of the expression of 4 genes in the patients with or without lymph nodes metastasis was not significant (P 0.05) . The positive correlation existed between GST-π and C-erbB2, GST-π and LRP, C-erbB2 and LRP , with the correlation coefficient being 0.323, 0.244 and 0.231 respectively. [Conclusion] The expression of GST-π, LRP and P-gp is mainly related to the primary multidrug resistance in breast carcinoma. Detecting the expression of the four genes before chemotherapy will provide evidence for the selection of drugs and for the judgement of the prognosis.