YKL-40 promotes invasion and metastasis of bladder cancer by regulating epithelial mesenchymal transition.

OBJECTIVE: This study aims to explore the relevance between YKL-40 and recurrence and progression of bladder cancer, and determine whether YKL-40 can be used as a potential target in patients with bladder cancer.

METHODS: We analyzed the invasion and metastasis ability of BIU-87, UMUC3, J82, T24, 5637 and immortalized human bladder epithelial cells SVHUC1 by Transwell method. The YKL-40 expression levels in cell lines were analyzed by Western blot and qPCR.

RESULTS: The increase of YKL-40 level, especially in tumour group, was related to tumour pathological stage and tumour invasion and metastasis. The cell lines with YKL-40 high expression had stronger invasion and metastasis ability. Overexpression of YKL-40 in SVHUC1 with the lowest YKL-40 expression can enhance the invasion and migration of cells. In T24 cells with YKL-40 high expression, transfection of shRNA plasmid targeting YKL-40 can down regulate the invasion and migration. The expression levels of N-cadherin and Vimentin in YKL-40 overexpressed SVHUC1 cells were increased, the E-cadherin expression was decreased, the Twist, Snail and Slug expression levels were increased, but they were opposite in T24 cells with down-regulation of YKL-40 expression.

CONCLUSIONS: YKL-40 promoted the migration and invasion of bladder cancer cells by up regulating the EMT gene expression. The YKL-40 expression is closely related to the invasion and migration of bladder cancer.