Pancreatic Cancer Research Today is a free monthly online journal that collates and summarizes the latest research about Pancreatic Cancer, including details on symptoms, causes, treatment, information. | ||||||||
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Aggressive pancreatic ductal adenocarcinoma in mice caused by pancreas-specific blockade of transforming growth factor-beta signaling in cooperation with active Kras expression.Ijichi H, Chytil A, Gorska AE, Aakre ME, Fujitani Y, Fujitani S, Wright CV, Moses HL Department of Cancer Biology, Vanderbilt University, Nashville, Tennessee 37232, USA. Pancreatic ductal adenocarcinoma (PDAC) is an almost uniformly lethal disease in humans. Transforming growth factor-beta (TGF-beta) signaling plays an important role in PDAC progression, as indicated by the fact that Smad4, which encodes a central signal mediator downstream from TGF-beta, is deleted or mutated in 55% and the type II TGF-beta receptor (Tgfbr2) gene is altered in a smaller subset of human PDAC. Pancreas-specific Tgfbr2 knockout mice have been generated, alone or in the context of active Kras (Kras(G12D)) expression, using the Cre-loxP system driven by the endogenous Ptf1a (pancreatic transcription factor-1a) locus. Pancreas-selective Tgfbr2 knockout alone gave no discernable phenotype in 1.5 yr. Pancreas-specific Kras(G12D) activation alone essentially generated only intraepithelial neoplasia within 1 yr. In contrast, the Tgfbr2 knockout combined with Kras(G12D) expression developed well-differentiated PDAC with 100% penetrance and a median survival of 59 d. Heterozygous deletion of Tgfbr2 with Kras(G12D) expression also developed PDAC, which indicated a haploinsufficiency of TGF-beta signaling in this genetic context. The clinical and histopathological manifestations of the combined Kras(G12D) expression and Tgfbr2 knockout mice recapitulated human PDAC. The data show that blockade of TGF-beta signaling and activated Ras signaling cooperate to promote PDAC progression. Published 20 November 2006 in Genes Dev, 20(22): 3147-60.
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