SLC31A1 is the major transporter for platinum drug intake, its expression correlates with drug disposition and response. In 1004 Chinese NSCLC patients with platinum-based chemotherapy, we investigated the association between SLC31A1 polymorphisms and clinical outcomes. Heterozygotes of rs10759637 at 3'UTR was associated with severe thrombocytopenia (odds ratio [OR]: 2.69; P = 0.012) and shorter overall survival (hazard ratio [HR]: 1.24; P = 0.005). Variant homozygote of rs2233914 was correlated with longer overall survival (hazard ratio [HR]: 0.73; P = 0.008). Haplotype and diplotype of these linked SNPs were associated with hematologic toxicities. In stratification analyses, rs10759637 and rs2233914 consistently correlated with overall survival in specific subgroups such as men, smoker, patients older than 58 years, or with ECOG PS 0-1, or with squamous cell carcinoma. rs10759637 could change the local structure of 3'UTR harboring putative binding sites for hsa-miR-29, whose transfection into 16HBE cells resulted in remarkable suppression of gene expression. The rs10759637 variant significantly correlated with lowered luciferase activity in reporter assays and decreased expression of SLC31A1 transcript in tumorous tissues. The study thereby identified functional polymorphism of SLC31A1 that modulates miRNA-3'UTR interaction and gene expression as potential pharmacogenetic biomarker for clinical outcomes of platinum-based chemotherapy in NSCLC patients.
Keywords: NSCLC; SLC31A1; SNP; microRNA; pharmacogenetics.