Effect And Mechanism Of MiRNA-217-5p On Invasion And Migration Of Prostate Cancer Cell

Part One Expression of miRNA-217-5p in prostate cancerObjective: Prostate cancer occurs in the male prostate and is one of the most common malignant tumors in men worldwide.Since 2000 to 2016,the incidence and mortality of prostate cancer in China have shown an increasing trend.Prostate cancer has many causes,studies have shown that micro RNAs(miRNAs)play a key role in the occurrence and development of tumors,so miRNA and prostate cancer related research has been focused on in recent years.Mir-217 can act as an oncogene or tumor suppressor and plays an important role in the development and progression of malignant tumors,and miRNA-217-5p can be involved as a regulator of prostate cancer.However,the function of miRNA-217-5p in prostate cancer is less studied at present.This study aimed to investigate the expression of miRNA-217-5p in prostate cancer.Method: To identify the role of miRNA-217-5p in prostate cancer,we detected the expression of miRNA-217-5p in prostate cancer tissues and prostate cancer cell lines,and the expression level of miRNA-217-5p was detected by real-time PCR.Result: Compared with adjacent non tumor tissues,the expression of miRNA-217-5p was significantly downregulated in prostate cancer tissues and cell lines.In addition,real-time PCR showed that miRNA-217-5p was minimally expressed in DU145 cells.Summary: Mi RNA-217-5p is down regulated in prostate cancer tumor tissues and cell lines,and miRNA-217-5p may have an anti-tumor effect in prostate cancer.Part Two Effect of miRNA-217-5p on invasion and migration of prostate cancer cellsObjective: Prostate cancer is not easy to metastasize because it is difficult to diagnose at an early stage,and there is no effective treatment currently.As the aging population increases,the disease and economic burden that prostate cancer poses to society will grow in the future.In the previous part of the study,we found that miRNA-217-5p was down-regulated in prostate cancer tumor tissues and cell lines,and miRNA-217-5p might have an anti-tumor effect in prostate cancer.The purpose of this part of the study is to further explore how miRNA-217-5p affects biological functions such as invasion and migration of prostate cancer.Method: To identify the role of miRNA-217-5p in prostate cancer biological function,we first constructed miRNA-217-5p knockin prostate cancer cell lines,followed by detecting its effect on cell metastasis and invasion by cell scratch and Transwell invasion assays.Result: After knockin of mir R-217-5p in prostate cancer cell lines,the metastasis and invasion abilities of the cells were significantly inhibited,and the results of cell scratch and Transwell invasion assays showed that the number of cells with metastasis and invasion decreased significantly.Summary: Mi RNA-217-5p has anti-cancer effect in prostate cancer.Overexpression of miRNA-217-5p in prostate cancer cells significantly inhibited their ability to migrate and invade.Part Three The regulatory mechanism of miRNA-217-5p on on invasion and migration of prostate cancer cellsObjective: In the previous part of the study,we found that miRNA-217-5p has an inhibitory effect on prostate cancer.Overexpression of miRNA-217-5p in prostate cancer cells can significantly inhibit their migration and invasion.The purpose of this study is to further explore the molecular mechanism behind the effects of miRNA-217-5p on biological functions such as invasion and migration of prostate cancer.Method: To further explore the related molecular mechanisms,we first detected the expression of epithelial mesenchymal transition(EMT)related proteins in miRNA-217-5p knockin cell lines and examined the protein expression levels of N-cadherin,vimentin,E-cadherin,MMP2 and MMP9 by Western blot.We next searched for target genes of miR-217-5p using software sequence alignment and dual luciferase reporter assay,and the protein expression of the target gene clusterin(clu)in the miRNA-217-5p knockin cell line was detected by Western blot.Finally,to identify whether miR-217-5p inhibits invasion and metastasis of prostate cancer by targeting clusterin,we first examined the expression of EMT related proteins in prostate cancer cells after co-transfection of miRNA-217-5p and clu,followed by si RNA interfe-rence to construct clu knockdown prostate cancer cell lines,and examined the effects of clu knockdown on cell metastasis and invasion and the expression of EMT related proteins.Result: Mi RNA-217-5p was able to regulate the expression of EMT related proteins,down regulate the protein expression of N-cadherin,vimentin,MMP2 and MMP9,and up regulate the protein expression of E-cadherin.Software sequence alignment showed that miRNA-217-5p may target clu3’UTR,and the results of dual luciferase reporter assay showed that miRNA-217-5p was able to significantly target and inhibit the expression of clu,and Western blot assay showed that the protein expression of clu was downregulated in the miRNA-217-5p knockin cell lines.Co-transfection of miRNA-217-5p and clu could reverse the expression regulation of EMT related proteins by miRNA-217-5p,which were upregulated by N-cadherin,vimentin,MMP2 and MMP9,and downregulated by E-cadherin.Clu knockdown inhibited cell metastasis and invasion abilities,and its regulation of EMT related protein expression was consistent with the trend of knockin of miRNA-217-5p,with downregulated protein expression of N-cadherin,vimentin,MMP2 and MMP9 and upregulated protein expression of E-cadherin.Summary: Mi RNA-217-5p regulated prostate cancer cell migration and invasion by targeting the expression of clu,which in turn inhibited the expression of tumor metastasis associated EMT proteins.Therefore,our findings provide a theoretical basis for the discovery of potential new diagnostic and therapeutic targets for prostate cancer.Conclusions:This study is the first to reveal the regulation of miRNA-217-5p expression in prostate cancer and the effects on prostate cancer cell invasion,migration,as well as the molecular mechanisms,as follows:1.The first part of the study showed that miRNA-217-5p was downregulated in prostate cancer tumor tissues compared with adjacent normal prostate cancer tissues,and that miRNA-217-5p was also significantly underexpressed in prostate cancer cell lines compared with normal prostate cancer cell lines.This part of the study reveals that miRNA-217-5p is closely related to the pathogenesis and progression of prostate cancer,and miRNA-217-5p can be used as a potential novel prostate cancer diagnostic marker.2.In the second part of the study,we showed that miRNA-217-5p was a tumor suppressor in prostate cancer,and prostate cancer cells were able to significantly inhibit their ability to migrate and invade after overexpression of miRNA-217-5p compared with the control Mir NC group.Mi RNA-217-5p may be a tumor suppressor miRNA in prostate cancer with potential as a novel molecular target for the treatment of prostate cancer.3.The third part of the study showed that miRNA-217-5p was able to regulate prostate cancer cell migration and invasion by targeting and inhibiting the expression of clu,and then inhibiting the expression of tumor metastasis related EMT proteins.In summary,miRNA-217-5p is significantly underexpressed in prostate cancer,which can inhibit EMT protein expression by targeting clu and affect prostate cancer cell migration and invasion.Mi RNA-217-5p is a tumor suppressor miRNA in prostate cancer and may serve as a potential diagnostic and therapeutic target for prostate cancer.