MDR1 C3435 Gene Polymorphism in Adult and Childhood Acute Lymphoblastic Leukemia of an Ethnic Iranian Population

Abstract

Abstract Multidrug resistance protein 1 (MDR1, Pgp, ABCB1) is a membrane efflux transporter protein encoded by the MDR1 gene. The overexpression of this gene has been linked with the resistance to a variety of cancer chemotherapeutic agents in cancer patients. It also has an important role in tissue and cell defense against xenobiotics and toxic-compounds insult. A gene polymorphism in exon 26 of MDR1 (C3435T) has been reported to be associated with a decreased expression of MDR1 in TT genotype carriers compared with those of the CC genotype. In the present study, the MDR1 C3435T polymorphism of an ethnic Iranian population with acute lymphoblastic leukemia (ALL) was studied, and the incidence of the genotypes was compared among patients in different age groups: ≥ 20 years of age (A) and 1-19 years of age (B). The percent distribution of genotypes were found to be TT (A: 21.4; B: 26.0), TC (A: 57.1; B: 60.0), and CC (A: 21.4; B: 14.0). The B group ALL patients (1-19 years) were further divided into 2 groups of 1-9 (Y) and 9-19 (Z) years of age, and their MDR1 C3435T genotypes were analyzed. The distribution of the genotypes were found to be as follows: TT (Y: 27.9; Z: 23.1), TC (Y: 60.7.1; Z: 59.0), and CC (Y: 11.5; Z: 17.9). No significant differences were found among different genotypes in the studied age groups. It was concluded that in the studied population no specific genotype (either TT, TC, or CC) in MDR1 C3435T gene polymorphism was associated with the incidence of ALL. Further studies will shed light on the possible importance of these findings.