Hereditary chronic pancreatitis induced plasticity cooperates with mutant Kras in early pancreatic carcinogenesis.

[BACKGROUND] Chronic pancreatitis (CP) is a risk factor for pancreatic cancer, with inherited cases conferring a markedly increased risk. The underlying mechanisms driving malignant transformation by CP remain poorly understood.

[OBJECTIVE] Combining a recently developed mouse model of CP carrying the human carboxypeptidase A1 () p.N256K mutation with the established pancreatic cancer model, we characterised mechanisms linking chronic inflammation to early pancreatic carcinogenesis.

[DESIGN] We crossed mice (Cpa1) with (KC). In Cre, Cpa1, KC and KC-Cpa1 mice, we performed phenotypical characterisation at five early time points and in an ageing cohort. Assessment of histology combined with both RNA-sequencing and single-cell RNA-sequencing was performed to analyse metaplasia, preneoplastic lesions and cellular heterogeneity.

[RESULTS] KC-Cpa1 pancreata displayed a stark increase in remodelling, fibrosis and formation of metaplastic lesions as compared with KC. induced extensive plasticity in both the acinar and ductal compartment, including an early acinar-to-ductal metaplasia state in acinar cells characterised by an upregulation of endoplasmic reticulum stress markers and an inflammatory ductal phenotype (iDucts). We characterised the complex cell-cell communication networks underlying both pancreatic inflammation and early carcinogenesis, revealing disease-specific signalling between ductal cells, granulocytes and fibroblasts.

[CONCLUSIONS] The humanised KC-Cpa1 mouse model reveals the interplay of inflammation in hereditary CP and carcinogenesis. -induced plasticity in acinar and ductal cells, inflammation and cell-cell interaction networks cooperate with in early pancreatic carcinogenesis.