CircZMIZ1 Acts As A MiR-1236-3p Sponge To Promote Prostate Cancer Cells Proliferation By Regulating CCND3 Expression

Background and purposeProstate cancer refers to the epithelial malignant tumor of prostate,in which prostate adenocarcinoma accounts for more than 95%.In China,due to the rapid development of Western lifestyle,aging population,and the popularity of prostate specific antigen(PSA)screening,the incidence of prostate cancer shows a trend of increasing year by year,and both the incidence and mortality are the fastest growing and the largest growth rate of male tumors.People pay more and more attention to the early diagnosis and treatment of prostate cancer.With the progress of clinical technology and scientific research,the cellular and molecular level of prostate cancer is more and more well understood.However,the etiology and progress mechanism of prostate cancer are not clear,and the treatment is lack of effective stem Preconditioning.Therefore,it is urgent to find a high specific and sensitive target for early diagnosis and treatment of prostate cancer.Circular RNA is a new type of RNA,which is different from traditional linear RNA.It has a closed ring structure,no 5’ cap structure and 3’ poly(a)structure.It is mainly located in the cytoplasm or stored in exosomes,not affected by RNA exonuclease,and its expression is more stable and not easy to degrade than ordinary linear RNA.It has been proved to exist in many eukaryotes.In recent years,a large number of studies have shown that circrna is closely related to the occurrence and development of many major human diseases,and its application prospects in disease diagnosis markers are predicted,but its role in the occurrence and development of prostate cancer is still unknown.circZMIZ1 is originated from exons 2,3 and 4 of ZMIZ1.ZMIZ1 gene is closely related to the development of prostate cancer and the expression of androgen receptor.However,the mechanism of circZMIZ1 in prostate cancer has not been reported.Based on this,our team plans to further study the expression and function of circZMIZ1 in prostate cancer cells,and clarify its mechanism in the occurrence and development of prostate cancer.MethodsIn this study,we screened circular RNAs in 4 pairs of matched prostate cancer and normal volunteers plasma by high-throughput Arraystar circRNA expression profile chip,and then selected the circRNA with significant difference by setting the difference multiple>3.0 times(P<0.001).After that,we determined circZMZI1 in 14 pairs of prostate cancer by qPCR.The expression of circZMIZ1 in the nucleus and cytoplasm of prostate cancer was detected by real-time fluorescence quantitative PCR;the expression of circZMIZ1 in the nucleus and cytoplasm of prostate cancer C4-2 was detected by RNA in situ fluorescence hybridization;the change of cell cycle distribution was analyzed by flow cytometry by knocking down the expression of circZMIZ1 The proliferation of prostate cancer cells in vitro was detected by Edu staining,CCK-8 assay,migration invasion and so on.By using bioinformatics to predict websites(https://circinteractome)and Targetscan website to predict the downstream targets and related protein molecules of circular RNA,we screened miRNAs with a score>90,and detected the miRNA level after RNA pull down in overexpressed circzmizl cells,and preliminarily explored the role of circZMIZ1 and downstream related signal molecules in the proliferation of prostate cancer cells.ResultsThe result of circRNA expression profile chip screened out 7131 circular RNAs,3268 circRNAs were up-regulated,3863 circRNAs were down-regulated,and the expression of circZMIZ1 was significantly increased in the peripheral serum of patients with prostate cancer and prostate cancer cells;CCK8,EdU and plate clone formation experiments showed that the proliferation ability of prostate cancer cells was decreased after the expression of circZMIZ1 was silenced;the cell cycle was blocked after silencing the expression of circZMIZ1;the migration and invasion ability of prostate cancer cells silenced by circZMIZ1 was significantly reduced.In addition,circZMIZ1 acts as a miR-1236-3p sponge to promote prostate cancer cells proliferation by regulating CCND3 expression.Conclusion1.The expression level of circZMIZ1 significantly increased in serum of patients with prostate cancer and prostate cancer cell lines,circZMIZ1 had the characteristics of closed loop RNA,which was relatively stable and could not be hydrolyzed by exonuclease;qPCR results and confocal microscopy showed that circZMIZ was expressed in both cytoplasm and nucleus,and the expression in cytoplasm was more than that in nucleus.2.The proliferation,clone formation and cell cycle of prostate cancer cells could be inhibited by sicircZMIZ1.3.circZMIZ1 acts as a miR-1236-3p sponge to promote prostate cancer cells proliferation by regulating CCND3 expression.It is expected to bring new ideas for the diagnosis and treatment of prostate cancer.