ABSTRACT: Hierarchical clustering of pancreatic cancer cell lines based on differentially regulated genes between mesenchymal and epithelial PDAC cells derived from primary tumours and metastases from KrasG12D-driven mouse models of pancreatic cancer.
Project description:Comparison of gene expression changes of pancreatic tissue from Ptf1aCre;KrasG12D and Ptf1aCre;KrasG12D;SnailKI/+ mice at the age of 1 month and 3 months.
Project description:Expression profiles of 28 murine pancreatic cancer cell lines isolated from a KrasG12D-based mouse model of pancreatic cancer mRNA of 28 low passaged murine pancreatic cancer cell lines was extracted and hybridized to Affymetrix microarrays
Project description:To investigate the role of SHP2 (Ptpn11) in pancreatic carcinogenesis, murine pancreatic whole tissue RNA samples of 9 week old mice with the genotypes Ptf1a-Cre;LSL-KrasG12D (ID-labels Kxxx) and Ptf1a-Cre;LSL-KrasG12D;Ptpn11fl/fl (ID-labels Mxxxx) were analyzed by microarray.
Project description:A pancreatic ductal adenocarcinoma cell line was isolated from a Pdx1-Flp, FSF-KRasG12D/+, Rosa26-CreERT2/tdEG, Mtor-lox/lox mouse. Cultured cells were treated with 4-Hydroxytamoxifen to induce CreERT2 mediated excision of floxed Exon 3 of Mtor.
Project description:The objective of this study was to elucidate the role of Nupr1 in pancreatic tumorigenesis. Using the Pdx-1-cre;LSL-KrasG12D mouse as model we discovered that, in contrast to KrasG12D pancreas that develop multiple foci of pancreatic intraepithelial neoplasia (PanIN), KrasG12D;Nupr1KO pancreas were free from such lesions, indicating that Nupr1 is pivotal for PanIN formation. In vitro, MiaPaCa2 cells activated Nupr1 expression in response to nutrient deprivation and this expression was necessary for cell survival. Mechanistically, Nupr1 protected cells from stress-induced death by inhibiting apoptosis through an alternative RelBàIER3-dependent pathway and independent from activation of the classical RelA-based NF-kB pathway. In agreement with these findings, Nupr1, RelB and IER3 proteins were found co-expressed in PanINs from KrasG12D pancreas. Moreover, pancreas-specific KrasG12D;RelbDpanc mice displayed a delay in PanIN development associated with a lack of IER3 expression, further emphasizing the relevance of this pathway in vivo. Efficient PanIN formation was therefore dependent on the expression of Nupr1 and RelB, with the probable involvement of IER3. Finally, a significant correlation between expression of Nupr1, RelB and IER3 and a poor prognosis of patients with PDAC was found. Altogether, our results reveal a novel stress-related pathway that requires the functional interaction of Nupr1àRelBàIER3 in KrasG12D-dependent transformation of the pancreas and expand our understanding of the molecular machinery that mediates the early steps of pancreatic carcinogenesis. Since Nupr1 belongs to the HMG family of chromatin remodelers with transcriptional co-factor activity, Nupr1 could increase cell survival in a nutrient-deprived microenvironment by activating the expression of pro-survival genes. Moreover, considering that RelB, and not RelA/p65, is essential to the Nupr1-mediated survival mechanism that takes place upon nutrient deprivation-induced stress, we made the hypothesis that the two NF-kB transcription factors should activate different sets of genes among which a pivotal pro-survival gene would be exclusively dependent on RelB. In order to test this two hypothesis, an Affymetrix microarray analysis was performed using pancreatic cancer cells transfected with siCtrl or siNupr1 and cultured for 3, 6 or 9 hrs in EBSS; or transfected with siRelB, siRelA/p65 or siCtrl and cultured for 9 hrs in EBSS or Mock.
Project description:We established a mouse model of KrasG12D, Trp53-/- and Sf3b1-K700E murine pancreatic cancer to elucidate the impact of the SF3B1 mutation found in human PDAC on the KPC mouse model.
Project description:Comparison of gene expression profiles of uninduced and Tamoxifen induced KrasG12D expression in pancreatic ductal epithelial cells (PDEC) and comparison of KrasG12D induced PDECs treated with vehicle, gefitinib or erlotinib
Project description:Nupr1 is a chromatin protein which cooperates with KrasG12D to induce PanIN formation in mice, though the molecular mechanisms underlying this effect remain to be fully characterized. In the current study, we find that Nupr1 acts as a gene modifier of the effect of KrasG12D-induced senescence by regulating Dnmt1 expression, changing the genome-wide levels of DNA methylation and activating the growth regulatory FoxO3a-Skp2-p27Kip1-pRb-E2F pathway. Congruently, 5-aza-2'-deoxycytydine, a general inhibitor of DNA methylation, reverses the KrasG12D-induced PanIN development through an effect on oncogene-induced senescence. Therefore, mechanistically this data reveals that epigenetic events modulate the functional outcome of genetic mutations during the progression of pancreatic cancer. The fact that small drug inhibitors of these epigenetic pathways reverse the effects triggered by genetic changes lends significant biomedical relevance to this knowledge for the future design of novel therapies aimed at controlling the progression of pancreatic cancer. The pancreatic gene expression profile of Nupr1 (+/+) Kras-G12D mouse was compared to the Nupr1 (-/-) Kras-G12D mouse.
Project description:The mechanisms involved in promoting metastasis of pancreatic ductal adenocarcinoma have yet to be elucidated. Here, we show that AnnexinA2 regulates the secretion of Semaphorin3D from pancreatic tumor cells allowing it to bind to its receptor PlexinD1 on the surface of the tumor cell, which induces invasion and metastasis. Knockdown of AnnexinA2 or Semaphorin3D decreases the metastatic potential of pancreatic tumor cells, while over expression of AnnexinA2 or Semaphorin3D is sufficient to rescue the invasion capacity of these cells. Clinically, we found that Semaphorin3D expression correlates with poor survival and increased metastatic potential in human PDA patients. This study identified a novel axon guidance pathway downstream of AnnexinA2 that can be targeted in the treatment of metastatic pancreatic cancer. Two primary pancreatic tumor cell lines were analyzed. The first primary line was derived from a KrasG12D/p53172H/Pdx-1Cre mouse, which served as the reference sample. The second primary line was derived from a KrasG12D/p53R172H/Pdx-1Cre/AnxA2-/- mouse.