Objective To explore the mechanism of long non-coding ribonucleic acid metastasis - associated lung adenocarcinoma transcript 1(LncMALAT1)regulating enhancer of Zeste homolog 2(EZH2)through competitive combination with microRNA-506-3p(miR-506-3p)to affect the proliferation of bladder cancer.Methods A total of 92 pairs of bladder cancer tissues and corresponding adjacent normal tissues were collected from surgical resections between January 2023 and October 2024.The expression levels of LncMALAT1 and EZH2 were detected using Western blot and qRT-PCR.The patients were divided into poor group(n=34)and good group(n=58)according to their prognosis.Clinical data, such as gender, age, tumor diameter, vascular invasion, TNM stage, and distant metastasis were collected, and the relationship between LncMALAT1 and EZH2 and the prognosis of bladder cancer patients was analyzed with clinical pathological indicators.Through in vitro experiments, including qRT-PCR Western blot, plate cloning and EdU experiment were conducted to verify the effect of LncMALAT1 on EZH2 expression and bladder cancer cell proliferation.Bioinformatics technology was used to predict the interaction between LncMALAT1 and miR-506-3p, and qRT-PCR was used to verify the change of miR-506-3p expression after up regulating LncMALAT1 expression in bladder cancer cells.Results The univariate results showed that vascular invasion, TNM stage, distant metastasis, LncMALAT1 and EZH2 expression levels were related to the poor prognosis of bladder cancer patients, and the difference was statistically significant(all P<0.05).The results showed that the expression of LncMALAT1 and EZH2 in bladder cancer was positively correlated.In vitro experiment results showed that after up regulating LncMALAT1 expression, EZH2 expression was significantly up-regulated, and the proliferation ability of bladder cancer cells was significantly improved(all P<0.05).QRT-PCR validation showed that the expression of miR-506-3p was significantly down regulated after the expression of LncMALAT1 was up-regulated(P<0.05), suggesting that LncMALAT1 could regulate EZH2 through competitive combination with miR-506-3p, thereby affecting the proliferation and progression of bladder cancer cells.Conclusions LncMALAT1 can promote the proliferation of bladder cancer cells by competitively combining with miR-506-3p to regulate EZH2, and then accelerate the proliferation of bladder cancer cells, which can provide a new potential target for the treatment of bladder cancer.