Prognostic Significance of the Expression of MRP and p53 in Colorectal Carcinoma

Chang, Ji Young; Min, Young Don; Kim, Kweon Cheon; Lim, Sung Chul

Abstract

Although MDR was previously thought to be predominantly caused by the expression of the MDR1 gene, it is now increasingly believed to be caused by other mechanism. Recently, over-expression of the multidrug resistance-associated protein (MRP) was suggested a possible mechanism for non-Pgp mediated MDR. Recent studies showed that MRP can confer resistance to a wide spectrum of natural product drug, but the clinical relevance of MRP-mediated MDR in human cancer is poorly understood. p53 is the most widely known tumor suppressor gene. It has been suggested that mutant p53 is related to abnormal proliferation of cell and some what is been related to cellular apoptosis. To determine the clinical significance of MRP and/or p53 expression in colorectal carcinoma, the authors investigated the expression of the MRP and p53 in 81 cases of primary colorectal carcinoma, the relationship between the MRP and/or p53 expression and clinical parameters including 5-yr. survival rate, and the relationship between the expression of MRP and p53. The results were as follows: 1) Of the 81 colorectal carcinomas, 36 (42%) were MRP positive and 28 (34%) were p53 positive. 2) The expression of MRP and/or p53 was not significantly correlated with sex, age, histologic grades, tumor invasion, tumor location, tumor size, lymph node metastasis, TNM stage and survival of patients. In conclusion, these results suggest that expression of MRP and/or p53 is neither related to the known prognostic factors nor a prognostic factor by itself.