Matrix Metalloproteinase 11 is a Potential Biomarker in Bladder Cancer Diagnosis and Prognosis

Purpose: Bladder cancer is one of the leading causes of cancer death all over the world, and half of patients are diagnosed at advanced stages with poor therapeutic response. Thus, developing new biomarkers for bladder cancer diagnosis and prognosis is urgently needed. Materials and Methods: Bioinformatic and gene ontology (GO) analysis were employed to screen highly upregulated and secretory tumor markers in the TCGA BLCA cohort. IHC in tissue microarray and ELISA in cancer cell culture medium were used to validate the expression of putative biomarkers in bladder cancer. Bisulfite sequencing was used to detect DNA methylation status in the promoter of putative genes. Results: In this study, MMP11 is first identified as one of the most differentially expressed genes (DEGs) in bladder cancer by meta-analysis in a TCGA bladder cancer cohort. The strong upregulation of MMP11 is confirmed at protein levels in both bladder cancer patients and cell lines. Mechanistic studies reveal that MMP11 promoter hypomethylation, but not genomic amplification or mutation, accounts for its enhanced expression in bladder cancer both in vitro and in vivo. Moreover, clinicopathological analysis indicates that MMP11 upregulation is associated with the tumor progression and poor survival in bladder cancer patients. Discussion: These findings suggest that MMP11, as a secretory protein, is a promising biomarker for diagnosis and prognosis in bladder cancer.