ROR2 regulates cellular plasticity in pancreatic neoplasia and adenocarcinoma (snATAC-Seq)

Cellular plasticity is a hallmark of pancreatic ductal adenocarcinoma (PDAC) starting from the conversion of normal cells to precancerous lesions to the progression of carcinoma subtypes associated with aggressiveness and therapeutic response. We found that normal acinar cell differentiation, maintained by the transcription factor Pdx1, suppresses a broad gastric cell identity that is maintained in metaplasia, neoplasia, and the classical subtype of PDAC in mouse and human. We have identified the receptor tyrosine kinase Ror2 as marker of a gastric metaplasia (SPEM)-like identity in the pancreas. Ablation of Ror2 in a mouse model of pancreatic tumorigenesis promoted a switch to a gastric pit cell identity that largely persisted through progression to carcinoma. In both human and mouse pancreatic cancer, ROR2 activity continued to antagonize the gastric pit cell identity, strongly promoting an epithelial to mesenchymal transition, conferring resistance to KRAS inhibition, and vulnerability to AKT inhibition. Nuclei were isolated from frozen tissue of Ptf1aERT, Ptf1aERT;K*, Ptf1aERT;Pdx1f/f and Ptf1aERT;K*;Pdx1f/f mice, 2 and 10 weeks after Tamoxifen-induced CreERT recombination (n=2). Nuclei were analyzed using snATACseq.