Association of a multidrug resistance 1 gene polymorphism and colorectal cancer in the Korean population

Multi-drug resistance 1 (MDR1) gene encodes P-glycoprotein, which is a transmembrane transporter that acts as an energy-dependent efflux pump of xenobiotics and various chemotherapeutic drugs. To investigate relationships between C3435T (exon 26) and G2677T/A (exon 21) polymorphisms of MDR1 and gastric cancer (GC) or colorectal cancer (CRC), 102 GC patients, 193 CRC patients, and 200 healthy subjects were genotyped by pyrosequencing analysis. The genotype frequencies of 2677T/A and A/A of MDR1 in CRC patients (5.7 %, 1.6 %, respectively) were significantly lower than controls (12.5 %, 5.0 %, respectively) (P < 0.05). There was no significant difference in the MDR1 genotype frequencies between GC patients and controls. Our findings suggest that the G2677T/A polymorphism of MDR1 is significantly associated with risk of CRC in the Korean population. © 2013 Institute of Korean Medicine, Kyung Hee University.