Functions of circular RNAs in bladder, prostate and renal cell cancer (Review)

Abstract

Circular RNAs (circRNAs) are a class of non-coding RNAs formed by covalently closed loops through back-splicing and exon-skipping. circRNAs have been confirmed to play a vital role in various biological functions, acting as microRNA sponges and reservoirs, as well as combining with RNA-binding proteins during the progression of multiple cancer types. Therefore, the present review evaluated recent research articles in PubMed that were published between November 2017 and September 2020. Key word search strings included: ‘Circular RNA (circRNA) AND bladder cancer (BC)’, ‘circular RNA (circRNA) AND prostate cancer (PCa)’ and ‘circular RNA (circRNA) AND renal cell cancer (RCC)’. In total, >58 circRNAs were found to be implicated in urological cancers, with several of the circRNAs targeting common carcinogenic pathways, such as the AKT, TGF-β, MAPK, VEGF and even metabolic pathways. circRNAs are important modulators of BC, PCa and RCC. circRNAs are functionally implicated in the pathogenesis of these cancer types, and have been found to act as biomarkers for the diagnosis and prognosis of urological cancer. However, to the best of our knowledge, the functions of circRNAs in tumors of the urinary system remain largely unknown and require further research.

Circular RNAs as Prognostic Biomarkers in Renal Cell Carcinoma: A Systematic Review and Meta-Analysis

“…These findings indicate the potential of circRNAs to be effective biomarkers. Furthermore, as previously reported, circRNAs have a critical role in promoting metastasis in RCC ( Yang et al, 2021 ). CircRNAs can contribute to tumorigenesis in RCC and promote proliferation and differentiation of RCC by regulating tumor-related signaling pathways ( Li et al, 2020a ) and activating transcription factors ( Chen et al, 2020a ).…”

Circ_0037866 Contributes to the Tumorigenesis of Renal Cell Carcinoma by Sequestering miR-384 to Elevate Chromobox 5 Expression

“…In recent years, circRNAs have attracted increasing research attention for their diverse impacts on the occurrence and development of RCC. Growing evidence hints at a significant role for the expression alterations of cir-cRNAs in biological characteristics of RCC [18,19]. For instance, circTLK1 functioned as an oncogene to expedite the metastasis and growth in RCC by modulating the miR-495-3p/CBL axis [20].…”

CircRNAs as potent biomarkers in ovarian cancer: a systematic scoping review

“…Genetic and epigenetic factors are the main ones [38,39]. Multiple recent studies have confirmed that circRNAs play a substantial role in the initiation and progression of various cancers, such as hepatic and renal carcinoma, and bladder, prostate, esophageal, breast, gastric and lung cancer [40][41][42][43][44][45]. Considerable evidence shows that these circRNAs function in a great number of cancers and play essential roles in their occurrence and development [46].…”