| ALDH1A3 is a cytosolic aldehyde dehydrogenase of the ALDH1 family that catalyzes the oxidation of retinaldehyde to retinoic acid, positioning it as a key regulator of local retinoid signaling in tissues where differentiation, survival, and stress responses are tightly controlled. The enzyme adopts the conserved ALDH fold with a catalytic cysteine in the active site and cofactor-binding elements that coordinate NAD⁺ during oxidation of aldehyde substrates; assembly into higher-order oligomeric states supports efficient processing of retinaldehyde pools that feed into retinoic acid–responsive transcriptional programs. ALDH1A3-derived retinoic acid engages retinoic acid receptors and retinoid X receptors to regulate gene expression, and this activity shapes the transcriptional landscape in neural and glial populations where differentiation, self-renewal capacity, and resistance to stress are linked to retinoid metabolism. In mesenchymal glioma stem cells, ALDH1A3 expression defines a subpopulation with high aldehyde dehydrogenase activity and aggressive behavior, and its enzymatic production of retinoic acid maintains expression of the survival factor tissue transglutaminase, which supports self-renewal, proliferation, and resistance to standard genotoxic treatments. Across glioblastoma and other gliomas, ALDH1A3 associates with mesenchymal transcriptional signatures and is connected to multiple pathways, including those that control epithelial–mesenchymal plasticity, extracellular matrix remodeling, and cellular responses to oxidative and metabolic stress. The enzyme participates in networks that intersect with ferroptosis, autophagy, and metabolic rewiring, where its regulation of aldehyde detoxification and retinoid signaling influences vulnerability to lipid peroxidation and cell-death pathways under therapy-induced stress. ALDH1A3 expression shows spatial segregation and nuclear-associated patterns in glioblastoma specimens, reflecting heterogeneous regulation across tumor niches and aligning with regions enriched in stem-like cells and treatment-resistant clones. Elevated ALDH1A3 in multiple cancer types, including high-grade gliomas, marks tumor subsets with enhanced stem-like traits, invasive potential, and poor outcome, linking this enzyme’s catalytic and signaling roles to disease progression and to pathway-level vulnerabilities that are of interest for targeted experimental modulation. |
