| BackgroundBladder cancer is the ninth most frequently diagnosed cancer inthe world.Its incidence rate and mortality rate have been increasing in recent decades.About 70-80%of the newly diagnosed bladder cancer patients present with non muscle invasive bladder cancer(NMIBC),which is characterized by 50-70%of the patients are prone to recurrence,and 10-20%of the patients progress to muscle invasive bladder cancer(MIBC).Bladder cancer has the characteristics of complex molecular heterogeneity,diverse clinical manifestations and poor treatment effect.Although the comprehensive treatment of bladder cancer is mainly surgery,supplemented by bladder perfusion and neoadjuvant chemotherapy,immunotherapy and radiotherapy,the 5-year survival rate of patients with bladder cancer is still at a low level.Ubiquitin associated domain containing protein 2(UBAC2)gene is located on chromosome 13q32.3,which encodes UBAC2 protein and is highly conserved in different species.It is reported that up regulation of UBAC2 expression can promote the progress of Behcet’s disease.Recently,more and more evidences show that UBAC2 is also closely related to the occurrence and development of malignant tumors.In addition,microarray data showed that the expression level of UBAC2 was related to the histological type and pathological grade of bladder cancer.However,the specific role and regulatory mechanism of UBAC2 in the occurrence and development of bladder cancer are still unclear.Objective to analyze the complex molecular regulatory mechanism of bladder cancer,and to explore the role of UB AC2 in the proliferation,recurrence and metastasis of bladder cancer,so as to lay a theoretical foundation for the clinical treatment of bladder cancer.Methods1.Real time RT-PCR,Western blot and immunohistochemistry were used to detect the mRNA and protein expression of the target gene in cells and tissues.2.The localization of UBAC2 and BCRC-3 in bladder cancer cells were observed by immunofluorescence(IF)assay.3.Short hairpin RNAs(shRNAs)were used to silence UBAC2 and establish a stable cell line of bladder cancer.4.Flow cytometry,colony formation,CCK-8 experiment and subcutaneous tumor formation model of human bladder cancer cells in nude mice were used to detect the proliferation of bladder cancer cells in vitro and in vivo5.Luciferase reporter assay was used to explore the effect of UBAC2 on p27 expression.6.RNA immunoprecipitation(RIP)and pull-down assay were used to detect the circRNAs binding to UBAC2.ConclusionIn this study,we found that both UBAC2 mRNA and protein levels were upregulated in BC tissues and cell lines,and knockdown of UBAC2 inhibited BC cells proliferation both in vitro and in vivo.Meanwhile,Kaplan-Meier survival plots of 406 BC cases from TCGA database showed that higher expression of UBAC2 in BC patients was associated with lower survival rate.Mechanistic studies revealed that knockdown of UBAC2 increased the expression of p27 by posttranscriptional regulation.Our previous study indicated that circular RNA BCRC-3(BCRC-3)promoted the expression of p27 through interacting with miR-182-5p,and reversed miR-182-5p-induced inhibition of p27 3’UTR activity.In the present study,we found that UBAC2 could bind to BCRC-3,and subsequently affected the interaction of BCRC-3 with miR-182-5p to inhibit the expression of p27.Furthermore,knockdown of BCRC-3 partly reversed the upregulation of p27 expression induced by knockdown of UBAC2.Our findings highlight a novel mechanism of UBAC2 in regulating p27 through affecting the function of BCRC-3,and provide a research basis for the diagnostic and therapeutic application of BC. |
