Extracellular Vesicle-Packaged MIR4435-2HG Facilitates Cigarette Smoke-Induced Bladder Cancer Progression through Enolase 1-Dependent Glycolytic Reprogramming

High Resolution Image Download MS PowerPoint Slide Epidemiological studies have reported that cigarette smoking promotes bladder cancer progression, but the corresponding biological mechanisms must be elucidated. Cigarette smoking-related extracellular vesicle (EV)-packaged long noncoding RNAs (lncRNAs) derived from bladder tumors were identified via RNA sequencing, tissue microarrays, and single-cell RNA sequencing. The clinical value of candidate EV-packaged lncRNAs was evaluated in the urine and plasma of bladder cancer patients with smoking history. The underlying mechanism of EV-packaged lncRNAs was explored using CRISPR/Cas9, Seahorse, and N4-acetylcytidine (ac4C) acetylation experiments in vivo and in vitro . The EV-packaged lncRNA MIR4435-2HG, which was originally secreted by M2 macrophages in response to exposure to the cigarette smoking-related carcinogen 4-aminobiphenyl (4-ABP), exhibited an abundant expression pattern. Mechanistically, 4-ABP promoted M2 macrophage polarization and increased fused in sarcoma (FUS) expression by inducing signal transducer and activator of transcription 6 (STAT6) phosphorylation, contributing to the direct packaging of MIR4435-2HG into M2 macrophage-derived EVs and subsequent delivery to recipient tumor cells. The nuclear EV-packaged MIR4435-2HG subsequently bound N -acetyltransferase 10 (NAT10) and increased the stability of the glycolysis regulator Enolase 1 (ENO1) through the ac4C modification; cytoplasmic EV-packaged MIR4435-2HG sponged miR-143-3p, increased ENO1 expression, and ultimately activated PI3K-Akt signaling for glycolytic reprogramming to promote tumor development. In addition, recipient tumor cells internalized EV-packaged MIR4435-2HG and simultaneously secreted chemokines to recruit monocytes, establishing a potential feed-forward loop between M2 macrophages and tumor cells. This study identified EV-packaged MIR4435-2HG as a crucial bladder cancer marker that mediates intercellular communication during cigarette smoke exposure, suggesting a promising approach for bladder cancer prevention and treatment.