Microfibril-associated protein 5 regulates epithelial-mesenchymal transition-related genes to promote migration and invasion of bladder cancer cells / 第二军医大学学报

ABSTRACT

Objective To investigate the expression of microfibril-associated protein 5 (MFAP5) in bladder cancer tissues and its biological effects on bladder cancer cells. Methods The surgical resection specimens of bladder cancer patients, who were diagnosed in Shanghai General Hospital of Shanghai Jiao Tong University, were collected, and the expression level of MFAP5 was detected using immunohistochemistry. The cancer-associated fibroblasts (CAFs) and normal fibroblasts (NFs) were isolated and purified from bladder tumor tissues and normal bladder tissues, respectively. The mRNA expression levels of MFAP5 in CAFs, NFs, and four kinds of human bladder tumor cell lines (T24, 5637, UMUC3 and J82) were detected using quantitative real-time polymerase chain reaction. The correlation of MFAP5 expression with the progression and malignancy of bladder cancer was analyzed using the bladder cancer expression profile data derived from the Cancer Genome Atlas (TCGA) database and the GSE13507 database of Gene Expression Omnibus (GEO). The T24 and 5637cells were treated with recombinant human MFAP5 protein to detect the effect on cell migration and invasion, as well as the expression of migration-associated proteins. Results MFAP5 was mainly expressed in the stroma of bladder cancer tissues, and its expression level was related to T stage and tumor grade of bladder cancer (both P<0.05). The mRNA expression level of MFAP5 in CAFs was significantly higher than those in NFs, and T24, 5637, UMUC3 and J82 cells (all P<0.01). The results of TCGA and GSE13507 database both showed that the overall survival of bladder cancer patients with high expression of MFAP5 was significantly shorter than that of patients with low expression of MFAP5 (both P<0.05). Gene set variation analysis showed that the expression level of MFAP5 increased with the degree of tumor malignancy (P<0.01), and its expression was closely related to expression of epithelial-mesenchymal transition-related genes such as cadherin 2, Twist1, matrix metalloproteinase 9 (MMP9), and zinc-finger E-box-binding protein 1 (ZEB1) (all P<0.01). In T24 and 5637 cells, the stimulation of recombinant human MFAP5 protein could up-regulate the expression of epithelial-mesenchymal transitionrelated proteins, including N-cadherin, MMP9, ZEB1 and Twist, and enhance the migration and invasion abilities (all P<0.01). Conclusion MFAP5 may be a potential molecular marker for predicitng the invasion and progression of bladder cancer.