LncRNA as a diagnostic and prognostic biomarker in bladder cancer: a systematic review and meta-analysis

Long noncoding RNAs in bladder cancer prognosis: A meta-analysis

BACKGROUND

Numerous studies have demonstrated the involvement of long non-coding RNAs (lncRNAs) in the tumorigenesis of bladder cancer (BC). The aim of this study was to investigate the possible correlations between the specific lncRNAs and the clinical outcomes in bladder cancer patients.

METHODS

We systematically searched the PubMed, EMBASE and the Cochrane Library databases for studies published up to October 15, 2018, and retrieved the suitable articles. Pooled odds ratios (ORs), hazard ratios (HRs) and 95% confidence intervals (95% CIs) were obtained by using fixed-effect or random-effect model.

RESULTS

Up-regulation of lncRNAs predicted unfavorable overall survival (OS) (HR: 2.01, 95%CI: 1.66-2.44, P < 0.001) and recurrence-free survival (RFS) (HR: 2.05, 95%CI: 1.43-2.94, P < 0.001) in BC patients, and the high expression of lncRNAs was significantly associated with distant metastasis (DM) (OR: 8.16, 95%CI: 4.45-14.99, P < 0.001).

CONCLUSION

Abnormal expression of relevant lncRNAs are potential novel markers for predicting the clinical outcomes of BC.

Long Non-coding RNA DLEU1 Promotes Cell Proliferation, Invasion, and Confers Cisplatin Resistance in Bladder Cancer by Regulating the miR-99b/HS3ST3B1 Axis

Although accumulating evidence has shown the important function of long non-coding RNAs (lncRNAs) in tumor progression and chemotherapy resistance, the role of lncRNA DLEU1 in regulating proliferation, invasion, and chemoresistance of bladder cancer (BCA) cells remains largely unknown. Here, we found that DLEU1 was upregulated in BLCA tissues and BCA patients with high DLEU1 expression exhibited a shorter survival time. Furthermore, mechanistic analysis and functional assays validated that DLEU1 induced cell proliferation, invasion, and cisplatin resistance of BCA cells by de-repressing the expression of HS3ST3B1 through sponging miR-99b. Low miR-99b and high HS3ST3B1 levels were correlated with worse prognosis in patients with BCA. Ectopic expression of HS3ST3B1 or inhibition of miR-99b reversed DLEU1 knockdown-mediated suppression of cell proliferation, invasion, and cisplatin resistance. Thus, our study revealed a novel role for the DLEU1/miR-99b/HS3ST3B1 axis in regulating proliferation, invasion, and cisplatin resistance of BCA cells.

Epigenetic Alterations in Bladder Cancer

PURPOSE OF REVIEW

Epigenetics refers to processes that alter gene expression without altering primary DNA. Over that past decade, there is a growing focus on epigenetic mechanisms in cancer research and its importance in cancer biology. This review summarizes epigenetic dysregulation in bladder cancer.

RECENT FINDINGS

Epigenetic alterations are overall shared across various grades and stages of bladder cancer. High grade invasive tumors demonstrate a greater degree and intensity of methylation and may have a unique methylation pattern. Environmental exposures may influence epigenetic alterations directly independent of genomic change. Non-coding RNAs play an important role in cancer phenotype, especially in the context of integrative genomic analyses. DNA hypermethylation and non-coding RNAs have potential as robust bladder cancer biomarkers; however, they require further study and validation. Changes in chromatin and histone modification are attractive targets for therapy and are currently in clinical trials. Epigenetic dysregulation may be an important key in improving the understanding of bladder cancer pathogenesis, especially through integrative genomic analyses. Deeper understanding of these pathways can help identify clinically relevant biomarkers and therapeutic targets to validate for diagnosis, monitoring, prognosis, and treatment for bladder cancer.