Genetic variations in Hippo pathway genes influence bladder cancer risk in a Chinese population

The Hippo pathway participates in development of numerous tumors through regulating tissue growth and cell fate. This study aimed to detect the association between the genetic variants in Hippo pathway genes and bladder cancer risk in a Chinese population. A case-control study of 580 cases and 1101 controls was performed to evaluate the association of single nucleotide polymorphisms (SNPs) in 39 candidate genes involved in the Hippo pathway with bladder cancer risk. A logistic regression model was used to assess the effects of SNPs on bladder cancer susceptibility. Candidate gene expression in human bladder cancer samples was detected using The Cancer Genome Atlas (TCGA) database and the Gene Expression Omnibus (GEO) datasets. We found that SNP rs755813 in WWC1 was significantly associated with a decreased risk of bladder cancer [odds ratio (OR) = 0.76, 95% confidence interval (CI) = 0.66-0.88, P = 3.63 × 10^-4], which was more common in patients with low grade and non-muscle invasive tumors. Younger subjects (age ≤ 65) (OR = 0.70, 95% CI = 0.56-0.86), females (0.35, 0.23-0.52) and non-smokers (0.72, 0.58-0.88) showed a pronounced association between the rs755813 C allele and risk of bladder cancer by stratified analysis. The WWC1 was upregulated in bladder cancer tissues according to TCGA and GEO datasets. These findings indicated that genetic variant of WWC1 gene in Hippo signaling pathway contributes to the decreased risk of bladder cancer in the Chinese population and may have the protective effect against the development of bladder cancer.