A potential prognostic model based on miRNA expression profile in The Cancer Genome Atlas for bladder cancer patients

The Role of miRNAs to Detect Progression, Stratify, and Predict Relevant Clinical Outcomes in Bladder Cancer

Bladder cancer (BC) is one of the most common types of cancer worldwide, with significant differences in survival depending on the degree of muscle and surrounding tissue invasion. For this reason, the timely detection and monitoring of the disease are important. Surveillance cystoscopy is an invasive, costly, and uncomfortable procedure to monitor BC, raising the need for new, less invasive alternatives. In this scenario, microRNAs (miRNAs) represent attractive prognostic tools given their role as gene regulators in different biological processes, tissue expression, and their ease of evaluation in liquid samples. In cancer, miRNA expression is dynamically modified depending on the tumor type and cancer staging, making them potential biomarkers. This review describes the most recent studies in the last five years exploring the utility of miRNA-based strategies to monitor progression, stratify, and predict relevant clinical outcomes of bladder cancer. Several studies have shown that multimarker miRNA models can better predict overall survival, recurrence, and progression in BC patients than traditional strategies, especially when combining miRNA expression with clinicopathological variables. Future studies should focus on validating their use in different cohorts and liquid samples.

The role of tumour microenvironment-driven miRNAs in the chemoresistance of muscle-invasive bladder cancer-a review

Successful treatment for muscle-invasive bladder cancer is challenged by the ability of cancer cells to resist chemotherapy. While enormous progress has been made toward understanding the divergent molecular mechanisms underlying chemoresistance, the heterogenous interplay between the bladder tumour and its microenvironment presents significant challenges in comprehending the occurrence of chemoresistance. The last decade has seen exponential interest in the exploration of microRNA (miRNA) as a tool in the management of chemoresistance. In this review, we highlight the miRNAs involved in the tumour microenvironment crosstalk that contributes to the chemoresistance in bladder cancer. Decrypting the role of miRNAs in the interplay beholds scope for future clinical translational application in managing the long-standing concerns of chemoresistance in muscle-invasive bladder cancer.

A four-miRNA signature in serum as a biomarker for bladder cancer diagnosis

BACKGROUND

Urinary bladder cancer (BCa) is globally the 10th most frequent cancer. As a novel diagnostic tool, miRNA in serum screening is non-invasive. This project aimed to determine particular serum miRNAs as novel biomarkers for diagnosing urinary BCa.

METHODS

We designed a three-phase study with 122 healthy controls (HCs) and 132 BCa patients. The 30 miRNAs' expressions in serum from HCs and BCa patients were detected during the screening phase. The miRNAs with the most dysregulation were tested in the training (HCs vs. BCa, 30 each) and validation (80 HCs vs. 82 BCa) phase further. The diagnostic ability of these candidate miRNAs was estimated by the receiver operating characteristic (ROC) curves as well as the area under the ROC curve (AUC). The miRNAs' target genes and their annotations to functions were predicted utilizing bioinformatic assays.

RESULTS

Six serum miRNAs (miR-124-3p, miR-182-5p, miR-1-3p, miR-196a-5p, miR-23b-3p and miR-34a-5p) had significantly different expression between BCa patients and HCs in the training and validation phase. The four-microRNA panel improved the diagnostic value, with AUC =0.985. The result of bioinformatic analysis showed that these miRNAs' target genes in the panel may be related to the MAPK signaling pathway in bladder cancer.

CONCLUSIONS

Our study identified a four-miRNA panel that is a non-invasive new biomarker for diagnosing BCa.