Project description:There are several studies supporting the role of HMG-CoA reductase inhibitors such as atorvastatin against carcinogenesis, in which inhibiting the generation of prenyl intermediates involved in protein prenylation plays the crucial role. Mutation of Kras gene is the most common genetic alteration in pancreatic cancer and the Ras protein requires prenylation for its membrane localization and activity. In the present study, the effectiveness of atorvastatin against pancreatic carcinogenesis and its effect on protein prenylation were determined using the LSL-KrasG12D-LSL-Trp53R172H-Pdx1-Cre mouse model (called Pankras/p53 mice). Five-week-old Pankras/p53 mice were fed either an AIN93M diet or a diet supplemented with 100 ppm atorvastatin. Kaplan-Meier survival analysis with Log-Rank test revealed a significant increase in survival in mice fed 100 ppm atorvastatin (171.9 ± 6.2 d) compared to the control mice (144.9 ± 8.4 d, P < 0.05). Histologic and immunohistochemical analysis showed that atorvastatin treatment resulted in a significant reduction in tumor volume and Ki-67-labeled cell proliferation. Mechanistic studies on primary pancreatic tumors and the cultured murine pancreatic carcinoma cells revealed that atorvastatin inhibited prenylation in several key proteins, including Kras protein and its activities, and similar effect was observed in pancreatic carcinoma cells treated with farnesyltransferase inhibitor R115777. Microarray assay on the global gene expression profile demonstrated that a total of 132 genes were significantly modulated by atorvastatin; and Waf1p21, cyp51A1, and soluble epoxide hydrolase were crucial atorvastatin-targeted genes which involve in inflammation and carcinogenesis. This study indicates that atorvastatin has the potential to serve as a chemopreventive agent against pancreatic carcinogenesis.
Project description:Activation of endogenously expressed KRas[G12D] in the pancreas of mice gives rise primarily to early stage PanIN lesions, however such lesions can occasionally progress to end-stage ductal adenocarcinoma (PDAC). Progression of KRas[G12D]- initiated lesions to PDAC is accelerated by modest expression of MYC from the Rosa26 locus. Deletion of 1 copy of endogenous c-Myc or both copies of endogenous Zbtb17 (aka Miz1), slows progression to PDAC and extends healthful survival of Pdx1-Cre;lsl-KRas[G12D];Rosa26-lsl-MYC[DM] (KMC) mice. Tumours were removed from mice with all 4 genotypes and validated by histological examination prior to RNA-SEQ analysis.
Project description:The goal of this study is to identify changes in gene expression between acinar and low-grade PanIN lesions in p48Cre;LSL-KrasG12D mice.
Project description:Nuclear Protein 1 (Nupr1) is a major actor of the cell stress response required for KrasG12D-driven formation of pancreatic intraepithelial neoplastic (PanINs) lesions in mice. We investigated the impact of Nupr1-depletion on the development and biology of murin pancreatic adenocarcinomas (PDAC) in the Pdx1-cre;LSL-KrasG12D;Ink4a/Arffl/fl (KIC) mice. We found that only one half of Nupr1-deficient mice developed PDAC. This is related to increased caspase 3 activity and low IER3 expression in Nupr1-deficient;KIC in the pancreas. Moreover, when Nupr1-deficient;KIC mice do develop PDAC, tumors present with impaired epithelial-to-mesenchymal transition (EMT). Transcriptoma analysis revealed that Nupr1-deficient and Nupr1wt;KIC PDACs presented enrichment of gene signatures of the human classical- and quasi-mesenchymal (QM)-PDAC respectively. Moreover, Nupr1-deficient;KIC PDACs shared with human classical-PDACs overexpression of Kras-activation genes. In addition, cells derived from Nupr1-deficient;KIC PDACs formed fewer microspheres in vitro compared to Nupr1wt;KIC cells, indicative of stemness impairment in the absence of Nupr1. Finally, we found that Nupr1-deficient;KIC cells were more sensitive to some anticancer drugs than their Nupr1wt counterpart. Hence, this study establishes the pivotal role of Nupr1 in PDAC progression after PanIN and in PDAC EMT in vivo, with an impact in PDAC cell stemness. As a consequence, according to absence or presence of Nupr1, KIC mice develop tumors that phenocopy human classical- or QM-PDAC, respectively, thus becoming attractive models for preclinical drug trials.
Project description:Nuclear Protein 1 (Nupr1) is a major actor of the cell stress response required for KrasG12D-driven formation of pancreatic intraepithelial neoplastic (PanINs) lesions in mice. We investigated the impact of Nupr1-depletion on the development and biology of murin pancreatic adenocarcinomas (PDAC) in the Pdx1-cre;LSL-KrasG12D;Ink4a/Arffl/fl (KIC) mice. We found that only one half of Nupr1-deficient mice developed PDAC. This is related to increased caspase 3 activity and low IER3 expression in Nupr1-deficient;KIC in the pancreas. Moreover, when Nupr1-deficient;KIC mice do develop PDAC, tumors present with impaired epithelial-to-mesenchymal transition (EMT). Transcriptoma analysis revealed that Nupr1-deficient and Nupr1wt;KIC PDACs presented enrichment of gene signatures of the human classical- and quasi-mesenchymal (QM)-PDAC respectively. Moreover, Nupr1-deficient;KIC PDACs shared with human classical-PDACs overexpression of Kras-activation genes. In addition, cells derived from Nupr1-deficient;KIC PDACs formed fewer microspheres in vitro compared to Nupr1wt;KIC cells, indicative of stemness impairment in the absence of Nupr1. Finally, we found that Nupr1-deficient;KIC cells were more sensitive to some anticancer drugs than their Nupr1wt counterpart. Hence, this study establishes the pivotal role of Nupr1 in PDAC progression after PanIN and in PDAC EMT in vivo, with an impact in PDAC cell stemness. As a consequence, according to absence or presence of Nupr1, KIC mice develop tumors that phenocopy human classical- or QM-PDAC, respectively, thus becoming attractive models for preclinical drug trials. We investigated the impact of the homozygous deletion of the Nupr1 gene on pancreatic adenocarcinoma development and biology in the Pdx1-cre;LSL-KrasG12D;Ink4a/Arffl/fl (KIC) mouse model.
Project description:Oncogene-induced senescence in early mPanIN lesions depends on intact RelA function in vivo. We investigated the difference in gene expression between KrasG12D pancreata with and without deletion of RelA. Pancreata from 7 day old mice were prepared, RNA was isolated and Affymetrix microarray expression analysis was performed.
Project description:Dinaciclib is a small molecule cyclin-dependent kinase inhibitor with the potential to treat multiple cancers. To better understand its cytotoxic action in pancreatic ductal adenocarcinoma (PDAC), we evaluated dinaciclib therapeutic effects in the transgenic mouse model (LSL-KrasG12D/+ ; LSL-Trp53R172H/+ ; Pdx-1-Cre mice; KPC mice). Tumor growth and microenvironment were dynamically monitored by magnetic resonance imaging (MRI). Dinaciclib therapy significantly delayed tumor progression (P < 0.001) and prolonged survival (P = 0.007) in KPC mice. In vitro assays showed that dinaciclib exerted antiproliferative effects on PDAC cells by increasing surface calreticulin expression and release of ATP. Dinaciclib treatment inhibited proliferation and induced apoptosis in KPC tumor as assessed by Ki67 and cleaved caspase 3, respectively. Particularly, the tumor infiltrating CD8+ T cells were increased after dinaciclib treatment in KPC mice. Additionally, the mean apparent diffusion coefficient values of KPC tumor calculated from diffusion weighted MR images were significantly lower after dinaciclib treatment (P = 0.033). These finding suggest that dinaciclib as a single agent can inhibit tumor growth and improve the overall survival in KPC mice.
Project description:Sulindac has been identified as a competitive inhibitor of aldo-keto reductase 1B10 (AKR1B10), an enzyme that plays a key role in carcinogenesis. AKR1B10 is overexpressed in pancreatic ductal adenocarcinoma (PDAC) and exhibits lipid substrate specificity, especially for farnesyl and geranylgeranyl. There have been no studies though showing that the inhibition of PDAC by sulindac is via inhibition of AKR1B10, particularly the metabolism of farnesyl/geranylgeranyl and Kras protein prenylation. To determine the chemopreventive effects of sulindac on pancreatic carcinogenesis, 5-week-old LSL-Kras(G12D)-LSL-Trp53(R172H)-Pdx-1-Cre mice (Pan(kras/p53) mice) were fed an AIN93M diet with or without 200 p.p.m. sulindac (n = 20/group). Kaplan-Meier survival analysis showed that average animal survival in Pan(kras/p53) mice was 143.7 ± 8.8 days, and average survival with sulindac was increased to 168.0 ± 8.8 days (P < 0.005). Histopathological analyses revealed that 90% of mice developed PDAC, 10% with metastasis to the liver and lymph nodes. With sulindac, the incidence of PDAC was reduced to 56% (P < 0.01) and only one mouse had lymph node metastasis. Immunochemical analysis showed that sulindac significantly decreased Ki-67-labeled cell proliferation and markedly reduced the expression of phosphorylated extracellular signal-regulated kinases 1 and 2 (ERK1/2), c-Raf and mitogen-activated protein kinase kinase 1 and 2. In in vitro experiments with PDAC cells from Pan(kras/p53) mice, sulindac exhibited dose-dependent inhibition of AKR1B10 activity. By silencing AKR1B10 expression through small interfering RNA or by sulindac treatment, these in vitro models showed a reduction in Kras and human DNA-J homolog 2 protein prenylation, and downregulation of phosphorylated C-raf, ERK1/2 and MEK1/2 expression. Our results demonstrate that sulindac inhibits pancreatic carcinogenesis by the inhibition of Kras protein prenylation by targeting AKR1B10.
Project description:Purpose: we used next generation sequencing to analyze gene expression profiles of pancreatic tissues from KrasG12D;Pdx1-Cre and miR-301a-/-;KrasG12D;Pdx1-Cre mice treated with caerulein. The goals of this study are to compare the different gene expression profiles of pancreatic tissue between KrasG12D;Pdx1-Cre and miR-301a-/-;KrasG12D;Pdx1-Cre mice treated with caerulein.
Project description:Constitutive Kras and NF-kB activation is identified as signature alterations in human pancreatic ductal adenocarcinoma (PDAC). Here, we report that pancreas-targeted IKK2/beta inactivation inhibited NF-kB activation and completely suppressed PDAC development. Our findings demonstrated that NF-kB is required for development of pancreatic ductal adenocarcinoma that was initiated by Kras activation. Pancreatic tissue from 4 groups of mice were used in this project: (1) the pancreas normal appearance of Pdx1-cre;KrasLSL-G12D;IKK2/beta mice, (2) the normal pancreas of Pdx1-cre;KrasLSL-G12D mice, (3) the pancreatic lesion of pancreatic intraepithelial neoplasia (PanIN) of Pdx1-cre;KrasLSL-G12D mice, and (4) the pancreatic lesion of PDAC of Pdx1-cre;KrasLSL-G12D mice. Each group included three mice. RNA samples from mouse pancreas were hybridized on GeneChip Mouse Gene 1.0 ST arrays (Affymetrix). Group (1) and group (2) were compared, and group (2), group (3) and group (4) were compared.