MDR1 polymorphisms affect the outcome of Chinese multiple myeloma patients

To illustrate the association of MDR1 (Multidrug Resistance 1) polymorphisms at loci 1236, 2677, 3435 and the prognosis of multiple myeloma (MM) in Jiangsu population.

A total of 129 MM patients were recruited from Jiangsu Province, China. The DNA was extracted from white blood cells (WBC) of peripheral blood and was amplified by polymerase chain reaction-allele specific primers (PCR-ASP). MDR1 polymorphisms at 3 loci were analyzed by electrophoresis followed by photograph or DNA direct sequencing. The association between the MDR1 and clinical outcomes were calculated by Graphpad and SPSS.

MDR1 alleles at locus C1236T with T had significant lower calcium level in MM patients compared with C. The genotype CT had a significantly prolonged progress free survival (PFS) compared genotype CC at locus C1236T (median time: 48 months vs. 28 months, respectively; p=0.0062; HR=0.21; 95%CI0.061-0.715) while patients carrying T allele (CT and TT) at locus C3435T had a longer PFS than patients without T allele (CC) (median time: 60 months vs. 29 months, respectively; p=0.038; HR=0.508; 95%CI 0.264-0.978). And a borderline significance was found in haplotype at loci 2677-3435 and PFS. No significant findings were revealed between OS and MDR1 polymorphisms.

MDR1 polymorphisms could affect the prognosis of multiple myeloma whereas more samples and a longer follow-up are also needed.