The Research Of E2F5 Transcription Factor On Ovarian Carcinogenesis, Progression And BRCA1 Expression

Background and objective: Ovarian cancer is a common malignant tumour in gynaecology,with poor prognosis and low survival rate,mostly in the middle and late stages,posing a serious threat to women’s health.PARP inhibitors,as targeted drugs for the treatment of ovarian cancer,improve the prognosis of patients with BRCA mutations,but the objective remission rate in patients with BRCA wild type is low.Patients with ovarian cancer who have an unmutated BRCA gene or are taking PARP inhibitors still have a poor prognosis.E2F5 is a transcription factor that is closely linked to the cell cycle,DNA repair,tumor development,and prognosis.It is especially important to study E2F5 for the diagnosis and treatment of ovarian cancer.Methods: Bioinformatics was used to investigate the relationship between E2F5 and ovarian cancer development,as well as BRCA1 expression:(1)GEPIA2 database to investigate the differential expression of the E2 F family in ovarian cancer tissues and normal tissues;(2)TCGA database to investigate the relationship between E2F5 and clinical features of ovarian cancer;(3)Kaplan-Meier plotter database to investigate the relationship between E2F5 and ovarian cancer.(4)GO enrichment analysis to study the function of E2F5;(5)GSVA enrichment analysis,co-expression network,and Pearson correlation analysis to study the correlation between E2F5 and BRCA1 gene.Secondly,the effect of E2F5 on ovarian cancer cells and BRCA1 expression was initially explored by experimental validation:(1)E2F5-sh RNA recombinant lentiviral expression vector was transfected into SKOV3 cells,and transfection efficiency and E2F5 gene knockdown effect were observed by real-time fluorescence quantitative polymerization chain reaction(RT-q PCR)and immunoblotting method(Western blot);(2)Changes in cell motility and migration ability were observed by cell scratch assay and Tanswell assay;(3)RT-q PCR and Western blot were performed to detect the expression of BRCA1 gene in SKOV3 cells after E2F5 knockdown to investigate the correlation between E2F5 and BRCA1.Results: Bioinformatics analysis revealed that E2F5 was highly expressed in ovarian cancer tissues compared to normal tissues,and the difference was statistically significant(P<0.05).E2F5 was found to be negatively and significantly correlated with ovarian cancer stage,and the difference was statistically significant(P<0.001).E2F5 was positively associated with poor prognosis in patients with ovarian cancer,with a statistically significant difference(P<0.05).E2F5 was involved in the BRCA1-related pathway and showed a positive correlation with BRCA1 expression.RT-q PCR and Western blot results showed that the m RNA and protein expression of E2F5 were significantly reduced in SKOV3 cells transfected with recombinant lentiviral E2F5-sh RNA,and the gene silencing effect was significant(P<0.05).Scratch healing assay and Transwell assay showed that the motility migration ability of SKOV3 cells in the E2F5-sh RNA gene silencing group was lower than that of control cells,and the difference was statistically significant(P<0.05).RT-q PCR and Western blot results showed that m RNA and protein expression of BRCA1 was decreased in SKOV3 cells in the E2F5-sh RNA gene silencing group,with statistically significant differences(P<0.05).Conclusions and significance: E2F5 influences ovarian carcinogenesis and development,and the E2F5 gene inhibits ovarian cancer cell motility and migration while also regulating BRCA1 expression.E2F5 is thought to be a potential ovarian cancer therapeutic target.