Study Of Mutidrug Resistance Gene Expression In Breast Cancer

OBJECTIVE This article in order to study the essence of the produce of MDR in breast cancer in the level of molecule, and open out the mechanism of MDR in breast cancer. To study the relationship between the expression of mdrl gene and chemotherapeutic drug resistance in breast cancer, and to select efficiency methods detecting MDR of breast cancer in clinic, and in order to make certain of the scheme of chemotherapeutic drugs. METHODS The method of tetrazolium-base decoloinetric assay (MTT assay) were used to examine the restrain rate of 5 kinds of chemotherapeutic drugs including cyclophosphamide, fliorouracil, methopterin, vincristine, and biaoroubixing, to breast cancercells in 27 cases of breast cancer specimens in vivid. The end concentration of 5 chemotherapeutic drugs is cyclophosphamide 80ug/ml, fliorouracil 240ug/ml, methopterin 12ug/ml, vincristine 0. 4ug/ml, and biaoroubixing 51. 9ug/ml. And in the same specimens, the mdrl gene were detected using the methods of fluorogenic quantitative PCR (FQ-PCR). To judge the relationship between the expression of mdrl gene and chemotherapeutic drug resistance in breast cancer. According to the difference between sensibilities of breast cancer cells to these 5 chemotherapeutic drugs, we selected the scheme of CMF or the scheme of CAP, and observed the curative effect and prognosis.RESULTS The restrain rate of 5 kinds of chemotherapeutic drugs including cyclophosphamide, fliorouracil, methopterin, vincristine, and biaoroubixing, to breast cancer cells were analysisd using ANOVA process. The outcome presented that these 5 chemotherapeutic drugs under the experimental concentration had significant difference (P<0.05) between the restrain rate to 27 cases of breast cancers. This hinted that the sensibilities of breast cancer cells to these 5 chemotherapeutic drugs were different. 27 cases of breast cancer were detected by FQ-PCR. The rate of expression of mdrl mRNA is 37.04%. The mdrl gene were detected positive in 10 cases. This confirmedthat mdrl gene resisted in breast cancer cells by nature. To analysis the relationship between the expression of mdrl gene and chemotherapeutic drug resistance in breast cancer, we found that these breast cancer cases resistanced Biaoroubixing expressed higher mdrl gene positive rate than the sensitive cases. There were significant difference (P<0.05) between them. The other 4 kinds of chemotherapeutic drugs did not have such significant difference. This expained that the expression of mdrl gene leads to MDR. 9 cases which were not sensitive to MTX used the scheme of CAP. 18 cases which were not sensitive to E-ADM or detected mdrl gene positive used the scheme of CMF. The released period of 27 cases were 7-26 months ,average 17 months. The curative effect were perfect.CONCLUSION Overexpression of mdrl gene was the main reason of MDR in breast cancer. The means of MTT assay in examination of antichemitherapic drug to breast cancer is useful, simple, and exact. It can be used to select sensitive chemotherapeutic drug in order to overcome MDR. FQ-PCR in detecting mdrl mRNA is precise and sensitive. It can be used to detect and predict the occurance of MDR and direct chemotherapy to breast cancer in clinic. It can be used as an important index that detecting the expression of mdrl mRNA of breast cancer cells in clinical to estate the result of chemotherapy and prognosis.POSTGRADUATED SUN MEI ( Pharmacology)DIRECTED BY WANG CHUNBO...