TBC1D24 promotes the progression of the breast cancer cells via ARF6/PLD axis under hypoxia.

ObjectiveBreast cancer remains a leading cause of cancer-related mortality worldwide, yet the molecular mechanisms underlying its progression are not fully understood. This study aimed to identify novel hypoxia-responsive genes that promote tumor aggressiveness and could serve as prognostic markers or therapeutic targets.MethodsThe integrative bioinformatics analyses were performed using the Gene Expression Profiling Interactive Analysis (GEPIA) and User-Friendly Analysis of Cancer Gene Expression Data (UALCAN) databases to screen for genes associated with survival and tumor stage in breast cancer. Functional validation was conducted in 4th tumor, 1st clone (4T1) and M.D. Anderson-Metastatic Breast-231 (MDA-MB-231) cells under hypoxia. Gene expression was analyzed by quantitative polymerase chain reaction and western blotting. Stemness and tumorigenic potential were evaluated using sphere formation, viability, and proliferation assays.ResultsTBC1 domain family member 24 (TBC1D24) was identified as a hypoxia-responsive gene significantly associated with poor prognosis. Mechanistically, hypoxia-inducible factor-1α upregulated TBC1D24, which in turn increased adenosine diphosphate-ribosylation factor 6 (ARF6) expression and activated the phospholipase D (PLD) signaling pathway. These changes promoted cell viability, proliferation, and stem-like characteristics.ConclusionsTBC1D24 mediates hypoxia-induced tumor progression by activating the ARF6/PLD signaling axis and promoting stemness in breast cancer cells, supporting its potential as a prognostic biomarker and therapeutic target.