Studies on the Relationship between Multidrug Resistance 1 Gene and Pancreatic Cancer

Abstract

To study the relationship between the expressions of multidrug-resistance, 1 (mdr1) gene-coded mRNA and its product P-glycoprotein (P-gp) and biological characteristics of tumor cells in patients with previously untreated primary pancreatic cancer (PC) for guiding significance to the clinical treatment. Expression of mdr1 mRNA and P-gp on paraffin embedded sections was detected by in situ polymerase chain reaction (ISPCR) and immunohistochemistry correspondingly from 150 cases of normal and abnormal pancreatic tissues including 97, 32 and 21 cases of pancreatic cancer, pancreatitis and P-gp were mainly found on the apical plasma membranes and in cytoplasms of endothelial duct cells in tumor and normal tissues. The positive staining rates of expression of the mdr1 mRNA and P-gp detected in all pancreatic tumors were significantly higher than that in pancreatitis and normal tissues correspondingly (P<0.05). Moreover, higher expressions of mdr1 mRNA and P-gp in tumor cells were correlated with some biological characteristics of PC, such as the degree of differentiation, aggressiveness and TNM stage of tumors (P<0.05). However, there was no correlation between the rate of expression of mdr1 mRNA and P-gp and some clinical findings including age, sex, location and tumor size. The expression of mdr1 gene was associated with “natural” multi-drug resistance in PC. There was an important guiding significance between the detection of expression of mdr1 gene and prediction of the sensitivity to chemotherapy of PC. Meanwhile, it probably could be used as one of profoundly parameters to assess the degrees of differentiation and prognosis in PC.