Relationship between LAPTM4B gene polymorphism and susceptibility of renal cell carcinoma and bladder cancer

Lysosomal-associated protein transmembrane-4 beta (LAPTM4B) gene has two alleles, LAPTM4B*1 and LAPTM4B*2. Previous studies have demonstrated that LAPTM4B*2 contributed to the risk of cancers. This study aimed to investigate the correlation between LAPTM4B polymorphism and the susceptibility to renal cell carcinoma (RCC) and bladder cancer (BCA). A case-control analysis was performed in 180 RCC and 91 BCA cases and 347 controls. LAPTM4B polymorphism was analyzed by polymerase chain reaction and electrophoresis. Chi-square test was used to calculate genotype frequency and other parametric distributions between cancer cases and controls. Unconditional logistic regression analysis models were used to calculate odds ratio (OR) with 95% confidence interval (CI). Results showed that allelic frequency of LAPTM4B*2 in the controls (24.06%) was significantly lower than in RCC (31.70%, P = 0.008) and BCA (35.71%, P = 0.009) cases. The risks for RCC and BCA increased 1.467 (95% CI 1.104-1.950) and 1.634 (95% CI 1.132-2.360) times in individuals carrying LAPTM4B*2 compared with those carrying LAPTM4B*1. RCC cases with LAPTM4B*1/2 and *2/2 have 1.476 (95% CI 1.008-2.161) and 2.231 (95% CI 1.089-4.569) higher risks than those carrying LAPTM4B*1/1. BCA risk in cases carrying LAPTM4B*1/2 and LAPTM4B*2/2 was 1.563-fold (95% CI, 0.932-2.622) and 2.900-fold (95% CI, 1.233-6.821) that of cases with LAPTM4B*1/1. No association between LAPTM4B genotypes and clinical parameters of RCC and BCA was found, except for smoking status in BCA. Conclusions: These findings suggested that LAPTM4B*2 was a risk factor for both RCC and BCA. LAPTM4B is a potential biomarker for susceptibility of RCC and BCA.