CircZNF609 inhibited bladder cancer immunotherapy sensitivity via enhancing fatty acid uptake through IGF2BP2/CD36 pathway

N6-methyladenosine-modified circQKI inhibits prostate cancer docetaxel-sensitivity via miR-188-3p/Beclin-1 pathway

BACKGROUND

Docetaxel (DTX) is used in the first-line chemotherapy for advanced castration-resistant prostate cancer (CRPC), but resistance remains a major clinical challenge. Circular RNAs (circRNAs) play critical roles in DTX resistance. This study aimed to investigate the mechanism of a novel circRNA, circQKI, in DTX resistance and its regulatory network in CRPC.

METHODS

DTX-resistant cell lines (PC3/DR and 22RV1/DR) were established, and circQKI's circular structure was validated by Sanger sequencing. CircQKI expression was modulated via siRNA knockdown and overexpression plasmids. Cell viability, apoptosis, and colony formation were assessed by CCK-8, flow cytometry, and clonogenic assays. The interaction between circQKI and miR-188-3p was verified by dual-luciferase reporter, RIP, and RNA pull-down. Autophagy activation was analyzed via Western blot and TEM. Subcutaneous xenograft models evaluated in vivo drug resistance. M6A modification was investigated through m6A RIP-PCR, METTL3/IGF2BP2 knockdown, and stability assays.

RESULTS

CircQKI was significantly upregulated in resistant cells and promoted DTX resistance by sponging miR-188-3p, thereby enhancing Beclin-1 expression and autophagy activation. Inhibiting Beclin-1 or co-treatment with chloroquine (CQ) partially restored DTX sensitivity. Mechanistically, METTL3-mediated m6A modification stabilized circQKI via IGF2BP2 recognition, leading to its accumulation in resistant cells. In vivo studies confirmed that circQKI overexpression reduced tumor sensitivity to DTX by enhancing autophagy.

CONCLUSION

circQKI drives DTX resistance via the miR-188-3p/Beclin-1 axis and autophagy activation, with its expression regulated by METTL3-dependent m6A modification and IGF2BP2. Targeting circQKI or autophagy pathways may offer novel therapeutic strategies to overcome DTX resistance in prostate cancer.

Circular RNAs: key players in tumor immune evasion

Immune responses against tumor antigens play a role in confining tumor growth. In response, cancer cells developed several mechanisms to bypass or defeat these anti-tumor immune responses-collectively referred to as "tumor immune evasion". Recent studies have shown that a group of non-coding RNAs, namely circRNAs affect several aspects of tumor immune evasion through regulation of activity of CD8 + T cells, regulatory T cells, natural killer cells, cytokine-induced killer cells or other immune cells. Understanding the role of circRNAs in this process facilitate design of novel therapies for enhancing the anti-tumor capacity of immune system. This review provides an outline of different roles of circRNAs in the tumor immune evasion.

N6-methyladenosine-modified RNF220 induces cisplatin resistance and immune escape via regulating PDE10A K48-linked ubiquitination in bladder cancer

Bladder cancer (BCa) remains one of the most prevalent malignancies worldwide, with cisplatin-based combination chemotherapy as the cornerstone of adjuvant treatment. However, cisplatin resistance frequently arises in advanced BCa, limiting therapeutic efficacy. Comparative proteomic analysis of cisplatin-sensitive and -resistant BCa cells identified phosphodiesterase 10A (PDE10A) as significantly downregulated at the protein level in resistant cells, despite unchanged mRNA levels, indicating post-transcriptional regulation. Functional assays demonstrated that PDE10A enhanced cisplatin sensitivity by promoting apoptosis. Mechanistically, the E3 ubiquitin ligase RNF220 directly interacted with PDE10A, facilitating its ubiquitination and degradation under cisplatin-resistant conditions. RNF220 overexpression markedly reinforced cisplatin resistance in vitro and in vivo. Furthermore, N6-methyladenosine (m6A) modification mediated by METTL3 stabilized RNF220 mRNA in an IGF2BP2-dependent manner. Additionally, RNF220 promoted PD-L1 expression by destabilizing PDE10A, thereby facilitating immune evasion in BCa. These findings establish RNF220 as a pivotal ubiquitinase that drives both cisplatin resistance and immune escape through PDE10A destabilization, highlighting its potential as a therapeutic target to enhance chemotherapy and immunotherapy efficacy in advanced BCa.

Targeting Metabolic Reprogramming in Bladder Cancer Immunotherapy: A Precision Medicine Approach

Bladder cancer, as a highly heterogeneous malignant tumor of the urinary system, is significantly affected by tumor metabolic reprogramming in its response to immunotherapy. This review systematically elaborates on the molecular mechanisms of abnormal glucose and lipid metabolism in the bladder cancer microenvironment and immune escape, and discusses precision treatment strategies based on metabolic regulation. In the future, it will be necessary to combine spatiotemporal omics and artificial intelligence technologies to construct a multi-target intervention system for the metabolic-immune interaction network, promoting a paradigm shift in precision treatment for bladder cancer.

Lycorine Suppresses Non-Small-Cell Lung Cancer Progression Through Activating STING Pathway and Stimulating an Antitumor Immune Response

Non-small-cell lung cancer (NSCLC) stands as a primary contributor to cancer-related deaths worldwide. It has been demonstrated that Lycorine (LYD), a naturally occurring active sesquiterpene present in Chinese medicinal plants, exhibits anti-cancer properties across various cancer cell lines. However, the underlying mechanisms of LYD-induced anti-tumor in NSCLC are not fully known. This study demonstrated that LYD significantly reduced the proliferation of NSCLC and induced apoptosis by increasing intracellular ROS levels. The inhibition of ROS using N-acetylcysteine (NAC) eliminated the apoptosis effects of LYD, resulting in increased cell viability. Additionally, LYD treatment significantly activated the STING pathway in NSCLC and induced the expression of CXCL10, CXCL9 and CCL5 in NSCLC cells. Mechanistically, LYD was found to significantly reduce the protein levels of P70S6K and S6K, which are key proteins involved in cell growth and survival. Notably, in vivo experiments demonstrated that LYD significantly inhibited the growth of H358 xenograft and LLC1 tumor, exhibiting anti-tumor activity by elevating CD8+ T cells in the NSCLC mouse model. Our findings suggest that LYD possesses potent anti-cancer properties in NSCLC by inducing apoptosis through ROS generation and modulating the STING pathway and key chemokines. Furthermore, LYD also exerts its antitumor effects by inhibiting crucial proteins involved in cell growth. Overall, LYD shows promise as a potential therapeutic agent for NSCLC treatment.

Non-coding RNAs in bladder cancer, a bridge between gut microbiota and host?

In recent years, the role of gut microbiota (GM) in bladder cancer has attracted significant attention. Research indicates that GM not only contributes to bladder carcinogenesis but also influences the efficacy of adjuvant therapies for bladder cancer. Despite this, interventions targeting GM have not been widely employed in the prevention and treatment of bladder cancer, mainly due to the incomplete understanding of the complex interactions between the host and gut flora. Simultaneously, aberrantly expressed non-coding RNAs (ncRNAs) have been frequently associated with bladder cancer, playing crucial roles in processes such as cell proliferation, invasion, and drug resistance. It is widely known that the regulation of GM-mediated host pathophysiological processes is partly regulated through epigenetic pathways. At the same time, ncRNAs are increasingly regarded as GM signaling molecules involved in GM-mediated epigenetic regulation. Accordingly, this review analyzes the ncRNAs that are closely related to the GM in the context of bladder cancer occurrence and treatment, and summarizes the role of their interaction with the GM in bladder cancer-related phenotypes. The aim is to delineate a regulatory network between GM and ncRNAs and provide a new perspective for the study and prevention of bladder cancer.