RESUMO
OBJECTIVE: Ovarian cancer (OC) ranks one of the most prevalent fatal tumors of female genital organs. Aberrant promoter methylation triggers changes of microRNA (miR)-375 in OC. Our study aimed to evaluate the mechanism of methylated miR-375 promoter region in OC cell malignancy and to seek the possible treatment for OC. METHODS: miR-375 promoter methylation level in OC tissues and cells was detected. miR-375 expression in OC tissues and cell lines was compared with that in demethylated cells. Role of miR-375 in OC progression was measured. Dual-luciferase reporter gene assay was utilized to verify the targeting relationship between miR-375 and Yes-associated protein 1 (YAP1). Then, Wnt/ß-catenin pathway-related protein expression was tested. Moreover, xenograft transplantation was applied to confirm the in vitro experiments. RESULTS: Highly methylated miR-375 was seen in OC tissues and cell lines, while its expression was decreased as the promoter methylation increased. Demethylation in OC cells brought miR-375 back to normal level, with obviously declined cell invasion, migration and viability and improved apoptosis. Additionally, miR-375 targeted YAP1 to regulate the Wnt/ß-catenin pathway protein expression. Overexpressed YAP1 reversed the protein expression, promoted cell invasion, migration and viability while reduced cell apoptosis. Overexpressed miR-375 in vivo inhibited OC progression. CONCLUSION: Our study demonstrated that demethylated miR-375 inhibited OC growth by targeting YAP1 and downregulating the Wnt/ß-catenin pathway. This investigation may offer novel insight for OC treatment.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Biomarcadores Tumorais/metabolismo , Metilação de DNA , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Neoplasias Ovarianas/patologia , Regiões Promotoras Genéticas , Fatores de Transcrição/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Apoptose , Biomarcadores Tumorais/genética , Proliferação de Células , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Prognóstico , Fatores de Transcrição/genética , Células Tumorais Cultivadas , Via de Sinalização Wnt , Ensaios Antitumorais Modelo de Xenoenxerto , Proteínas de Sinalização YAPRESUMO
Bladder cancer is common and widespread, and its incidence is increasing. Many new diagnostic methods combined with state-of-the-art technology have been introduced in cystoscopy to collect real-time images of the bladder mucosa for diagnosis, but often miss inconspicuous early-stage tumors. Fluorophore-labeled peptides with high sensitivity and specificity for cancer would be a desirable tool for the detection and treatment of tiny or residual bladder tumors. Phage display and the human non-muscle-invasive bladder cancer cell line BIU-87 were used to identify a peptide. The isolated phage display peptide (CSSPIGRHC, named NYZL1) was tested in vitro for its binding specificity and affinity. Accumulation into xenograft tumors in a nude mouse model was analyzed with FITC-labeled NYZL1. NYZL1, with strong tumorhoming ability, was identified by in vivo phage library selection in the bladder cancer model. The NYZL1 phage and synthetic FITC-labeled NYZL1 peptides bound to tumor tissues and cells, but were hardly detected in normal control organs. Notably, accumulation of FITC-NYZL1 in bladder tumor cells was time-dependent. Biodistribution studies of xenografts of BIU-87 cells showed accumulation of injected FITC-NYZL1 in the tumors, and the bound peptide could not be removed by perfusion after 24 h. The mouse model of bladder tumor showed increased fluorescence intensity in the tumor-bearing bladder in comparison with normal bladder tissues after 4-6 h. In conclusion, NYZL1 may represent a lead peptide structure applicable in the development of optical molecular imaging.