Abstract 3163: Wnt7a promotes bladder cancer cell invasion via canonical Wnt/β-Catenin signaling

Abstract

Abstract The mortality rate of urinary bladder cancer (UBC) increases dramatically, once low grade non-muscle invasive bladder cancer develops into muscle invasive bladder cancer. Hence, understanding the mechanisms underlying UBC invasion/metastasis and identification of biomarkers for invasion/metastasis will help clinicians to determine how to treat patients. Herein we generated two sublines from parental 5637 UBC cells with low invasive and high invasive capacities, which were designated as 5637 NMI and 5637 HMI, respectively. Mass spectrometry analysis was performed to identify the invasion-associated proteins. 5,987 proteins were quantified across all six samples with the coefficients among different channels all nearly 1.00, suggesting good biological repeatability and minor differences between 5637 HMI and NMI samples. Fold change > 1.2 and p value <0.05 were set as the cut-off standard, and 16 upregulated proteins and 26 downregulated proteins were identified in 5637 HMI cells. Among them, Wnt7a overexpression was confirmed in 5637 HMI cells compared to 5637 NMI cells, which was also associated with metastasis potential and worse clinical outcome in UBC patients. Depletion of Wnt7a in 5637 HMI and T24 cells reduced UBC cell invasion, with the reduction of active β-Catenin and its downstream target genes involved in epithelial-to-mesenchymal transition (EMT) and extracellular matrix (ECM) degradation. Consistently, introduction recombinant Wnt7a protein to 5637 NMI and J82 cells induced cell invasion, EMT, and the expression of ECM degradation-associated genes. Using luciferase reporter driven by the wildtype or mutants of matrix metalloproteinase 10 (MMP10) promoter, a canonical Wnt/β-Catenin regulation pattern was demonstrated. Four miRNAs downregulated in UBCs were predicted directly targeting Wnt7a using bioinformatics analysis. miRNA mimic could decrease Wnt7a expression, reduce the activation of MMP 10 reporter and suppress the invasion of 5637 HMI cells. Treatment of UBC cells with Wnt7a partially abrogated such miRNAs-induced invasion suppression. Taken together, our data identify a new miRNA/Wnt7a axis to mediate cell invasion and metastasis of UBC through canonical Wnt/β-Catenin pathway, which may offer prognostic and therapeutic opportunity. Citation Format: Ruimin Huang, Xiaojing Huang, Hongwen Zhu, Junlong Zhuang, Yu Dong, Hu Zhou, Hongqian Guo, Jun Yan. Wnt7a promotes bladder cancer cell invasion via canonical Wnt/β-Catenin signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3163.