Abstract: Objective To investigate the effect of the expression of long noncoding RNA (lncRNA) VPS9D1-AS1 in bladder cancer on the clinical manifestations and malignant biological behavior of bladder cancer. 
Methods In total, 69 samples of cancer tissue and normal bladder epithelium were collected from patients with bladder cancer, who were treated in the Department of Urology, the Fourth Hospital of Hebei Medical University. The expression of VPS9D1-AS1 in bladder cancer tissue was detected by quantitative real-time polymerase chain reaction (qPCR), and its correlation with gender, age, smoking, hypertension, pathological grades, T stages, lymph node metastasis and distant metastasis was analyzed. The impacts of knockdown and overexpression of VPS9D1-AS1 on proliferation, migration and invasion ability of bladder cancer cells in vitro were investigated by cell proliferation assay, colony-forming assay, wound healing assay and Transwell invasion assay. 
Results The expression of VPS9D1-AS1 in the bladder cancer tissue was significantly higher than that in the normal bladder epithelium (P＜0.01). The expression of VPS9D1-AS1 in the high-grade urothelial carcinoma group was significantly higher than that in the low-grade urothelial carcinoma group (P＜0.01). Knockdown and overexpression of VPS9D1-AS1 could inhibit and enhance the proliferation, migration and invasion ability of bladder cancer cell lines, respectively. 
Conclusion LncRNA VPS9D1-AS1 increases the malignancy of bladder cancer cells and enhances the malignant biological behavior of bladder cancer cells. 

Key words: urinary bladder neoplasms, non-codingRNA, biological behavior