| Study objective: Prostate cancer is the most common malignant tumor in the male reproductive system.Its incidence ranks second among all male malignant tumors worldwide,and the five-year survival rate of patients with castration-resistant prostate cancer is only 30%,which seriously endangers male health.Therefore,it is extremely important to explore the molecular mechanisms of prostate cancer in order to improve early diagnosis and the efficacy of late-stage treatment,and to find new biomarkers and therapeutic targets.micro RNAs(miRNAs)are endogenous non-coding small molecules that regulate gene expression by modulating m RNA,and abnormal expression of miRNAs has been reported in prostate cancer cells and tissues.miRNAs play a role in the occurrence,development and metastasis of prostate cancer and can serve as potential new targets for diagnosis and treatment.Specifically,miR-148a-3p has been reported to be abnormally expressed in the serum of prostate cancer patients,but its role in the development and progression of prostate cancer is still unclear.N6-methyladenosine(m6A)is the most common dynamic and reversible RNA modification in eukaryotes and is widely present in m RNA and miRNA in humans.Multiple studies have shown that m6 A modifications are involved in the occurrence and development of prostate cancer,and methyltransferase-like 3(METTL3)is highly expressed in prostate cancer cells and tissues,but its specific molecular mechanisms are unclear.Therefore,exploring the roles and underlying molecular mechanisms of m6 A modifications and miRNAs in the development and progression of prostate cancer can provide new targets and ideas for diagnosis and treatment.This study aims to explore the mechanisms by which METTL3 regulates miR-148a-3p expression through m6 A modification and affects the development of prostate cancer.Study methods: RT-q PCR and Western blotting were used to measure the expression levels of METTL3,miR-148a-3p,and TXNIP in cells.Me-RIP experiments were performed to observe the m6 A modification level of pri-miR-148a-3p.A bioinformatics website was used to predict the expression levels of miR-148a-3p and TXNIP in prostate cancer and their correlation.The binding sites between miR-148a-3p and TXNIP were verified by dual-luciferase reporter assay.Cell proliferation,migration,invasion,and apoptosis were detected by CCK-8 test,Transwell assay,and flow cytometry,respectively.A nude mouse xenograft model was established to observe the tumor growth rate in each group.Immunohistochemistry was performed to detect TXNIP expression in tumor tissue.Study results:(1)Compared with normal prostate epithelial cells,METTL3 was highly expressed in prostate cancer cells,especially in DU145.Knockdown of METTL3 significantly inhibited cell proliferation,migration,and invasion of prostate cancer,and promoted cell apoptosis.Overexpression of METTL3 significantly promoted cell proliferation,migration,and invasion of prostate cancer,and inhibited cell apoptosis.(2)Compared with normal prostate epithelial cells,miR-148a-3p was highly expressed in prostate cancer cells.METTL3 could up-regulate the m6 A modification level of pri-miR-148a-3p and promote the expression of miR-148a-3p.Overexpression of miR-148a-3p could reverse the inhibitory effect of METTL3 knockdown on cell proliferation,migration,and invasion of prostate cancer,and the promoting effect on cell apoptosis.Interference with miR-148a-3p could reverse the promoting effect of METTL3 overexpression on cell proliferation,migration,and invasion of prostate cancer,and the inhibitory effect on cell apoptosis.(3)Starbase website prediction found that miR-148a-3p and TXNIP had targeted binding sites,and dual-luciferase reporter gene experiments confirmed that miR-148a-3p negatively regulated TXNIP.RT-q PCR and Western blotting showed that the expression of TXNIP in DU145 cells significantly decreased after overexpression of miR-148a-3p,and significantly increased after interference with miR-148a-3p.A rescue experiment showed that overexpression of TXNIP could reverse the promoting effect of miR-148a-3p on cell proliferation,migration,and invasion of prostate cancer,and the inhibitory effect on cell apoptosis.Knockdown of TXNIP could reverse the inhibitory effect of interfering with miR-148a-3p on cell proliferation,migration,and invasion of prostate cancer,and the promoting effect on cell apoptosis.(4)In animal experiments,interference with METTL3 inhibited tumor growth in nude mice by suppressing miR-148a-3p and promoting TXNIP expression.Study conclusion: METTL3 is highly expressed in prostate cancer cells and promotes the expression of miR-148a-3p by mediating m6 A modification of pri-miR-148a-3p,thereby down-regulating TXNIP and promoting the progression of prostate cancer. |
