ALDH1A3 promotes aggressive basal-like pancreatic cancer through an AP-1/RUNX2 enhancer network.

The basal-like transcriptional subtype of pancreatic ductal adenocarcinoma (PDAC) is linked to therapy resistance and poor prognosis. The cancer stem cell marker aldehyde dehydrogenase 1A3 (ALDH1A3) is a critical enzyme in acetaldehyde metabolism, but the interconnection to the basal-like subtype is poorly understood. Here, we identified ALDH1A3 as a key gene, which correlates with reduced survival and increased tumor growth. Functional studies revealed interaction of ALDH1A3 with genes like FAM3C, MCC, PMEPA1, and IRS2, forming a network driving PDAC progression. Chromatin profiling showed that ALDH1A3 affects acetylation of histone 3, mediating AP-1 activity, particularly via FOS family members, activating oncogenic pathways such as MAPK and TNF signaling. RUNX2 emerged as a therapeutic target within this network, as its knockdown disrupted MAPK signaling and reduced tumor growth. These findings emphasize the role of ALDH1A3 in linking nuclear metabolic-epigenetic programming in basal-like PDAC, highlighting it as a promising therapeutic target for novel treatment strategies.