MDR1 gene polymorphisms: possible association with its expression and clinicopathology characteristics in colorectal cancer patients.

AIM Over-expression of some genes, such as MDR1, can increase the level of chemotherapy drug afflux and limit the effectiveness of treatment. We aimed to investigate the effect of MDR1 polymorphisms on its expression level and related characteristics in Iranian colorectal cancer patients. METHODS Tumor, normal mucosal tissue and blood samples from CRC patients and blood samples from healthy controls (n=60) were obtained for genotyping and measuring the expression level of MDR1. RESULTS The expression of the MDR1 gene showed a significant increase in cancerous regions compared to adjacent normal tissue. Furthermore, the GG2677 genotype was correlated with highest while the AT 2677 genotype was associated with the lowest levels of expression. In addition only the G2677T/A polymorphism showed association with histological grade of colorectal tumors. CONCLUSION Our study once more emphasizes effects of MDR1 SNPs which may indirectly impact on response to drugs.