CircHGS enhances the progression of bladder cancer by regulating the miR-513a-5p/VEGFC axis and activating the AKT/mTOR signaling pathway

CircBRWD1 promotes hepatitis B virus replication and hepatocellular carcinoma progression by regulating the miR-513a-5p/TNPO1 axis

Hepatocellular carcinoma (HCC), primarily caused by chronic hepatitis B virus (HBV) infection, remains a leading cause of liver cancer worldwide. Despite advances in antiviral therapies, persistent HBV replication, mediated by covalently closed circular DNA (cccDNA), contributes to poor prognoses and frequent recurrence of HCC. This study investigates for the first time the role of circular RNA circBRWD1 in HBV-related HCC, aiming to elucidate its function and regulatory mechanism in HBV replication and hepatocarcinogenesis. Results showed that circBRWD1 was significantly overexpressed in HBV-positive HCC tissues and cell lines compared to HBV-negative controls and promoted HBV replication by increasing cccDNA accumulation. Silencing circBRWD1 markedly reduced the levels of HBV DNA, HBV surface antigen (HBsAg), HBV e antigen (HBeAg), and HBV core antigen (HBcAg), indicating its critical role in HBV replication. Functionally, circBRWD1 knockdown led to reduced cell proliferation, colony formation, and migration while increasing apoptosis in HCC cells. Mechanistic studies revealed that circBRWD1 acts as a sponge for miR-513a-5p, thereby upregulating TNPO1, a key player in promoting HCC malignancy. Rescue experiments confirmed that TNPO1 overexpression reversed the effects of circBRWD1 depletion, restoring cell proliferation, migration, and HBV replication. Additionally, circBRWD1 depletion significantly reduced tumor growth with reduced expression of TNPO1 and increased miR-513a-5p levels in a mouse xenograft model. Collectively, this study identifies circBRWD1 as a key oncogenic circRNA that facilitates HBV replication and HCC progression via the miR-513a-5p/TNPO1 axis. Targeting circBRWD1 may offer a novel therapeutic strategy for HBV-related HCC, potentially addressing the challenge of HBV persistence and improving patient outcomes.

CircRAPGEF5 sponges miR-582-3p and targets KIF3A to regulate bladder cancer cell proliferation, migration and invasion

BACKGROUND

Bladder cancer (BCa) is a common malignant disease with high recurrence and poor prognosis. Several circular RNAs (circRNAs) have been found to be associated with the malignant progression of bladder cancer (BCa). Here, the aim of this study was to investigate the expression, role and mechanism of circRAPGEF5 in BCa progression.

METHODS

Quantitative real-time PCR (qRT-PCR) and immunoblotting were used to detect gene and protein expression levels. In vitro functional studies were performed using CCK-8, colony formation, wound healing and Transwell assays, respectively, and a mouse xenograft tumor model was established to perform in vivo experiments. Bioinformatic predictions as well as luciferase reporter assays and RNA pull-down assays were used to probe circRAPGEF5-mediated competitive endogenous RNA (ceRNA) network.

RESULTS

CircRAPGEF5 was significantly overexpressed in BCa patients (p < 0.05), indicating a potential unsatisfactory prognosis. Functionally, knockdown of circRAPGEF5 inhibited the growth, migration and invasion of BCa cells in vitro (p < 0.05), as well as BCa growth in vivo (p < 0.05). Mechanistically, circRAPGEF5 acted as a sponge for miR-582-3p and targeted kinesin family member 3A (KIF3A). In addition, rescue experiments showed that inhibition of miR-582-3p or overexpression of KIF3A reversed the anticancer effects of circRAPGEF5 knockdown on BCa cells (p < 0.05).

CONCLUSION

Silencing circRAPGEF5 inhibits BCa proliferation, migration and invasion via the miR-582-3p/KIF3A axis, demonstrating a promising target for BCa-targeted therapy.

Molecular mechanism of microRNAs, long noncoding RNAs, and circular RNAs regulating lymphatic metastasis of bladder cancer

Bladder cancer (BC), a malignancy originating in the epithelial tissue in the inner wall of the bladder, is a common urological cancer type. BC spreads through 3 main pathways: direct infiltration, lymphatic metastasis, and hematogenous metastasis. Lymphatic metastasis is considered a poor prognostic factor for BC and is often associated with lower survival rates. The treatment of BC after lymphatic metastasis is complex and challenging. A deeper understanding of the molecular mechanisms underlying lymphatic metastasis of BC may yield potential targets for its treatment. Here, we summarize the current knowledge on epigenetic factors-including miRNAs, lncRNAs, and circRNAs-associated with lymphatic metastasis in BC. These factors are strongly associated with lymphangiogenesis, cancer cell proliferation and migration, and epithelial-mesenchymal transition processes, providing new insights to develop newer BC treatment strategies.