Ductal vs. acinar? Recent insights into identifying cell lineage of pancreatic ductal adenocarcinoma
Pancreatic ductal adenocarcinoma (PDAC) is a deadly disease with a 5-year survival rate of less than 8%. To date, there are no early detection methods or effective treatments available. Many questions remain to be answered in regards to the pathogenesis of PDAC, among which, the controversy over the cell lineage of PDAC demands more attention. Ductal cells were originally thought to be the cell of origin for PDAC due to the ductal morphology of most cases of PDAC. However, recent studies have demonstrated that acinar cells are more sensitive to KRAS mutation and tend to develop to PanIN and PDAC effectively, very likely by undergoing acinar to ductal metaplasia into a transient state that contributes to PDAC initiation. There is also evidence that both ductal and acinar cells can potentially develop to PDAC when exposed to certain genetic settings and stimuli, suggesting that more scrutiny is required for the identification of the true cell lineage of individual cases of PDAC. In this work, we summarize recent findings in the identification of the cellular origin of PDAC, with the goal of advancing our knowledge on the initiation and progression of the disease. We also discuss various models and techniques for investigating early events of PDAC. Better understanding of these cellular events is crucial to identify new methods for the early diagnosis and treatment of PDAC.