Project description:We have carried out transcriptional profile analysis in WT MICE and bitransgenic Pdx1-cre/Kras*A MICE baring Pancreatic Ductal Adenocarcinoma Mouse models faithfully simulating human cancer are valuable for genetic identification of potential drug-targets but, among them, the most advantageous for practical use in subsequent preclinical testing of candidate therapeutic regimes are those exhibiting rapid tumor development. Considering that a KRAS mutation (predominantly in codon 12, such as KRASG12D; KRAS*) occurs with high frequency (~90%) in cases of human pancreatic ductal adenocarcinoma (PDA)1, we sought to develop a mouse PDA model that would exhibit high tumor incidence and short latency by ectopic overexpression of Kras*. Five WT mice and 6 bitransgenic Pdx1-cre/Kras*A MICE baring Pancreatic Ductal Adenocarcinoma were used to identify key genes in the formation of panceatic malignacies
Project description:We recently established the ERK-dependent transcriptome and phosphoproteome in KRAS-mutant pancreatic ductal adenocarcinoma (PDAC). Of 1,718 ERK-dependent genes, 143 encode transcription factors. Of 2,123 ERK-dependent phosphoproteins, 98 are transcription factors. Despite this complexity, we observed that genetic suppression of the MYC transcription factor alone phenocopied KRAS suppression in signaling, growth and metabolic processes. To establish a molecular basis for MYC support of KRAS-ERK-driven PDAC growth, we determined the gene transcription changes caused by acute loss of MYC function and identified 1,685 MYC-dependent (UP) and 1,325 MYC-inhibited (DN) genes. Dependency Map analyses demonstrated that MYC UP but not DN genes are essential for PDAC growth. Instead, pathway analyses support MYC DN genes as a secondary RHO GTPase-mediated compensatory response to oncogenic stress. We found that 36% of ERK-dependent genes are MYC-dependent, supporting the dominant role of MYC in driving ERK-regulated gene expression. Finally, proteomic profiling revealed that MYC regulated a complex kinome comprised of protein kinases that likely contribute to MYC-driven cancer growth. We conclude that MYC supports KRAS-ERK-dependent PDAC growth through regulation of a complex transcriptome and kinome.
Project description:Constitutive Kras and NF-kappaB activation is identified as signature alterations in human pancreatic ductal adenocarcinoma (PDAC). However, the mechanisms of constitutive NF-kappaB activation in KrasG12D-induced PDAC are not yet understood. Here, we report that pancreas-targeted IKK2/beta inactivation inhibited NF-kappaB activation and completely suppressed PDAC development in KrasG12D and KrasG12D;Ink4a/Arf mutant mice, demonstrating a genetic link between IKK2/beta and KrasG12D in PDAC inception. Our findings reveal that KrasG12D-activated AP-1 induces IL-1alpha, which in turn activates NF-kappaB and its target genes IL-1alpha and p62, to initiate IL-1alpha/p62 feedforward loops for inducing and sustaining NF-kappaB activity. Furthermore, IL-1alpha overexpression correlates with Kras mutation, constitutive NF-kappaB activity, and poor survival in PDAC patients. Therefore, our findings establish a pathway linking duel feedforward loops of IL-1alpha/p62 through which IKK2/beta/NF-kappaB is activated by KrasG12D. To study Kras-induced inflammatory responses and to identify differentially expressed genes between the pancreatic tissues of Pdx1-Cre;KrasLSL-G12D and Pdx1-Cre;KrasLSL-G12D;IKK2/betaF/F mice, cDNA microarray analysis was performed.
Project description:In this dataset, we include the expression data obtained from KRas expressing tumors, matched Kras expressing tumor spheres, surviving cells and surviving cells after KRas re-expression for 24hs Data reported here are obtained from 5 independent tumors (from 1 to 5). For each tumor, expression data for the original Tumor (in vivo bulk tumor lesion), the KRas Expressing Spheres derived from the bulk tumor, the matched surviving cells after 8 days of KRas ablation (SCs) and Surviving Cells after 24 hours of KRas re-expression are reported.
Project description:We utilized non-transformed, human pancreatic ductal epithelial (HPDE) cells, previously engineered with the E6 and E7 proteins of the HPV16 virus to emulate loss of p53 and inactivation of the Rb pathway, respectively. Given the frequent activation of KRAS (>90% PDAC tumors) and its early role in pancreatic neoplasia, we sought to engineer HPDE cells containing KRASG12D to provide the appropriate context in which to screen for novel drivers that might represent KRAS effectors. The KRAS-induced transcription analysis was conducted using RNAs extracted from HPDE cells transduced with either control, wild-type KRAS or KRASG12D(pInducer) with or without DOX (100ng/ml) for 72 h, followed by hybridization of labeled cDNA onto Agilent arrays (Agilent G3 Human GE 8x60K) by the Baylor College of Medicine Genome Profiling Core Facility. multi-group comparison
Project description:Bicaudal C1 KO embryonic pancreas develops cysts and has less endocrine progenitors after E14.5 (14.5 days after fertilization), while no defect is observed at E13.5. Bicaudal C1 is an RNA-binding protein. To understand the molecular mechanisms leading to both phenotypes, the mRNA expression profile of E13.5 WT vs. Bicaudal C1 dorsal pancreas was studied by high-throughput sequencing using the Illumina HiSeq 2000 platform. This time point was selected as a time point where no phenotypic modification was detected. 3 replicates for each condition were sequenced and each replicate consisted of 3 E13.5 dorsal pancreas of the same genotype. There were only few differences between both transcriptomes. Pkd2 was 1.9-fold reduced in Bicaudal C1 KO. Pkd2 inactivation causes renal and pancreatic cyst. Some genes having immune/inflammatory functions were up or downregulated highlighting the early immune cell infiltration observed in Bicaudal C1 KO pancreas. No hit could explain the endocrine progenitor decrease. It may be due to the ability of Bicaudal C1 to regulate mRNA translation without affecting the mRNAs themselves. Comparison of mRNA profiles of E13.5 WT vs. Bicaudal C1 KO dorsal pancreas using the Illumina HiSeq 2000 platform (platform ID SN865), 3 replicates per condition.
Project description:Oncogenic STAT3 functions are known in various malignancies. We found that STAT3 plays an unexpected tumor suppressive role in KRAS-mutant non-small-cell-lung cancer (NSCLC). In mice, tissue-specific inactivation of Stat3 resulted in increased Kras (G12D)-driven NSCLC initiation and malignant progression leading to markedly reduced survival. Clinically, low STAT3 expression levels correlate with poor survival in human lung adenocarcinoma patients with smoking history. Consistently, KRAS-mutant lung tumors showed reduced STAT3 levels. Mechanistically, we show that STAT3 controls NFκB-induced IL-8-expression by sequestering NFκB in the cytoplasm while IL-8 in turn regulates myeloid tumor infiltration and tumor vascularization thereby promoting tumor progression. These results identify a novel STAT3-NFκB-IL-8 axis in KRAS-mutant NSCLC with therapeutic and prognostic relevance WT: Control lung; KRAS: Lung tumors expressing KRAS G12D; KRAS STAT3 KO: Lung tumors expressing KRAS G12D- STAT3 deficient; tumors of four mice pooled per sample
Project description:Extracellular matrix (ECM) is an important component of the pancreatic microenvironment which regulates β cell proliferation, differentiation and insulin secretion. Protocols have recently been developed for the decellularization of the human pancreas to generate functional scaffolds and hydrogels. In this work, we characterized human pancreatic ECM composition before and after decellularization using isobaric dimethylated leucine (DiLeu) labeling for relative quantification of ECM proteins. A novel correction factor was employed in the study to eliminate the bias introduced during sample preparation. In comparison to the commonly employed proteomic approaches (urea and FASP), a recently developed surfactant and chaotropic agent assisted sequential extraction/on pellet digestion (SCAD) protocol was proven to be a superior strategy for ECM protein extraction of human pancreatic ECM matrix. The quantitative proteomic results revealed the preservation of matrisome proteins while most of the cellular proteins were removed. This method was compared with a well-established label-free quantification (LFQ) approach which rendered similar expressions of different categories of proteins (collagens, ECM glycoproteins, proteoglycans, etc.). The distinct expression of ECM proteins was quantified comparing adult and fetal pancreas ECM, shedding light on the correlation between matrix composition and post-natal β cell maturation. Despite the distinct profiles of different subcategories in the native pancreas, the distribution of matrisome protein exhibited similar trends after the decellularization process. Our method generates the largest dataset of matrisome proteins from a single tissue type. These results provide valuable insight into the possibilities of constructing a bioengineered pancreas. It also facilitates an understanding of the significant roles that matrisome proteins play in post-natal cell maturation.
Project description:Pooled KRC (LSL-KrasG12D; Rb1L/L; Pdx1-Cre: oncogenic Kras and deleted Rb1 in the pancreas) cells derived from 2 month old mice were compared to pooled KC (LSL-KrasG12D; Pdx1-Cre: oncogenic Kras in the pancreas) cells derived from 8 month old mice.