ADAMTS۹-AS۲ suppresses hypoxia-driven glycolytic reprogramming through EZH۲-dependent regulation of ENO۱ alternative splicing in bladder cancer

Objective(s): Tumor hypoxia is a key driver of metabolic reprogramming and aggressive progression in bladder cancer; however, the upstream long non-coding RNA (lncRNA)-mediated epigenetic mechanisms that regulate these processes remain incompletely understood. This study investigated the role of ADAMTS۹-AS۲ in hypoxia-induced metabolic remodeling and its interaction with EZH۲ and ENO۱ alternative splicing.Materials and Methods: Bladder cancer cell lines (T۲۴ and UM-UC-۳) were cultured under hypoxic or normoxic conditions. Stable knockdown and overexpression models of ADAMTS۹-AS۲, EZH۲, and ENO۱ were generated using lentiviral vectors. Functional assays included CCK-۸, colony formation, wound-healing, Transwell invasion, Seahorse XF metabolic analysis, glucose uptake, lactate/ATP quantification, ROS detection, JC-۱ staining, and transmission electron microscopy. Molecular interactions were assessed by RNA-FISH, RNA immunoprecipitation, biotinylated RNA pull-down, ChIP-qPCR, and RNA sequencing with alternative splicing analysis (rMATS/SUPPA۲). In vivo effects were evaluated using subcutaneous xenograft models with bioluminescence imaging and immunohistochemistry. Rescue experiments established pathway causality.Results: Hypoxia significantly reduced ADAMTS۹-AS۲ expression, which correlated with advanced clinicopathological stage and poor survival. ADAMTS۹-AS۲ directly interacted with nuclear EZH۲ and regulated chromatin remodeling at the ENO۱ locus, thereby altering ENO۱ alternative splicing. Loss of ADAMTS۹-AS۲ promoted glycolysis, mitochondrial dysfunction, ROS accumulation, proliferation, migration, invasion, and xenograft growth. Conversely, ENO۱ silencing or EZH۲ signaling restoration attenuated these malignant phenotypes.Conclusion: ADAMTS۹-AS۲ acts as a hypoxia-responsive tumor suppressor that restrains bladder cancer progression by regulating the EZH۲/ENO۱ signaling axis. These findings identify a novel lncRNA-mediated epigenetic mechanism linking hypoxia, alternative splicing, and metabolic reprogramming, highlighting ADAMTS۹-AS۲ and the EZH۲/ENO۱ pathway as promising therapeutic targets for bladder cancer.

کلیدواژه ها:

Urinary bladder neoplasms ، Chromatin remodeling ، Glycolysis ، Tumor hypoxia ، Enolase