| Bladder cancer(BC)is one of the most common malignant tumors.The incidence of BC have increased over the years in China and diagnostic and monitoring methods currently available are uncomfortable and costly for these patients.Therefore,development of non-invasive and sensitive molecular biomarkers is necessary to improve the diagnostic and monitoring strategies for BC.Urine is the most attractive sample for the diagnosis of BC due to the fact that it can be collected non-invasively.In recent years,various urine biomarkers have been approved by FDA for clinical practice,and the sensitivity and specificity of these biomarkers,however,are inadequate,making them suboptimal in clinical practice.Exosomes are an important component of extracellular carriers that mediate intercellular communication among components in tumor microenvironment and play roles in the formation and development of tumors.Studies have revealed that many potential non-invasive biomarkers are present in exosomes and exosomes are massively released into biological fluids,including blood,and urine.MicroRNAs(miRNAs)are small non-coding single-stranded RNAs consisting of 18-24 bases.MiRNAs with tumor-promoting functions are found in BC cells.The lipid bilayer membrane of the exosomes can protect miRNAs against the damage from RNases.When recognized,miRNAs interact with their receptors or undergo endocytosis to enter the recipient cells to work.Urine exosomes directly contact with tumor tissue in the urinary tract and miRNA content in exosomes may better reflect the status of local lesions,making enrichment and analysis of miRNAs in urine exosomes a potentially favorable strategy for early diagnosis and monitoring of BC Objective: To determine and compare the expression levels of miRNA-221-3p in urine exosomes between the bladder tumor patients and the healthy controls,and to explore the diagnostic value of urine exosome miRNA-221-3p for bladder tumors.Methods: Patients admitted to the Urology Department of Subei People’s Hospital of Jiangsu Province and pathologically diagnosed as BC after operation,including 24 patients with 18 non-muscle invasive BC and 6 muscular invasive BC,were enrolled in this study.12 healthy subjects were selected in the same period as the control group.A total of 36 urine samples were obtained,from which exosomes were isolated by ultracentrifugation.The morphological characteristics of these exosomes were observed by transmission electron microscopy and the expression level of miRNA-221-3p in these exosomes was detected by real-time fluorescent quantitative PCR.Difference in miRNA-221-3p expression in urine exosomes between the BC patients and healthy controls was analyzed using the SPSS24 software,and the efficacy of miRNA-221-3p in the diagnosis of BC was evaluated by the receiver operating characteristic(ROC)curve.Results: The results of transmission electron microscope showed that urine exosomes in both the patients and normal subjects were round or oval vesicles with a diameter of30-150 nm and a complete lipid envelope.Statistically significant difference in the expression of miRNA-221-3p in urine exosomes was observed between the BC group and the healthy control group(P<0.05).The area under the ROC curve(AUC)was0.818,and the sensitivity and specificity of miRNA-221-3p for the diagnosis of BC were 81.8% and 80%,respectively.Conclusion: Exosomes are successfully isolated from the urine of BC patients and healthy subjects by ultracentrifugation and miRNA-221-3p is extracted from exosomes and detected in the present study.The expression level of miRNA-221-3p in urine exosomes of BC patients is significantly higher than that of the control group(P<0.05).The findings of this study suggest that urine exosome miR-221-3p may serve as a potential diagnostic marker for bladder tumors.Sample size can be further increased in the future studies to verify the diagnostic value of miR-221-3p for bladder tumors. |
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