Project description:Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer with a low survival rate. Recently, new drugs that target KRASG12D, a common mutation in PDAC, have been developed. We studied one of these compounds, MRTX1133, and found it was specific and effective at low nanomolar concentrations in patient-derived organoid models and cell lines harboring KRASG12D mutations. Treatment with MRTX1133 upregulated the expression and phosphorylation of EGFR and HER2, indicating that inhibition of ERBB signaling may potentiate MRTX1133 anti-tumor activity. Indeed, the irreversible pan-ERBB inhibitor, afatinib, potently synergized with MRTX1133 in vitro, and cancer cells with acquired resistance to MRTX1133 in vitro remained sensitive to this combination therapy. Finally, the combination of MRTX1133 and afatinib led to tumor regression and longer survival in orthotopic PDAC mouse models. These results suggest that dual inhibition of ERBB and KRAS signaling may be synergistic and circumvent the rapid development of acquired resistance in patients with KRAS mutant pancreatic cancer.
Project description:Inflammatory transcription networks have been linked with the development of pancreatic ductal adenocarcinoma (PDAC). Here, we demonstrate that NFATc1 is both necessary and sufficient to drive progression of KrasG12D-initiated PDAC, particularly in the context of inflammation. Significantly, nuclear NFATc1 accelerates PDAC development in KrasG12D mice, whereas conditional NFATc1 deletion or pharmacological inhibition attenuates inflammation-mediated carcinogenesis. Mechanistically, NFATc1 induces STAT3 expression, complex formation and signal integration in PDAC. Genome-wide ChIP-sequencing and expression analysis in cells derived from c.n.NFATc1;KrasG12D mice identified combinatorial NFATc1/STAT3 binding at chromatin enhancer sites and subsequent regulation of key molecules involved in oncogenic signaling, growth and inflammation. Together, this study supports the relevance of inflammatory transcription factor networks in pancreatic carcinogenesis and provides a theoretical platform for therapeutic targeting of NFATc1 nucleoprotein complexes in PDAC. NFATc1 ChIP followed by high throughput sequencing in primary murine pancreatic cancer cells (referred to as NKC cells) derived from transgenic mice with pancreas-specific constitutive activation of NFATc1 and KrasG12D mutation in the presence or absence of STAT3 shRNA; 2 ChIP samples (scramble DNA and shSTAT3 DNA) and 1 unenriched input control from the same chromatin pool.
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:Inflammatory transcription networks have been linked with the development of pancreatic ductal adenocarcinoma (PDAC). Here, we demonstrate that NFATc1 is both necessary and sufficient to drive progression of KrasG12D-initiated PDAC, particularly in the context of inflammation. Significantly, nuclear NFATc1 accelerates PDAC development in KrasG12D mice, whereas conditional NFATc1 deletion or pharmacological inhibition attenuates inflammation-mediated carcinogenesis. Mechanistically, NFATc1 induces STAT3 expression, complex formation and signal integration in PDAC. Genome-wide ChIP-sequencing and expression analysis in cells derived from c.n.NFATc1;KrasG12D mice identified combinatorial NFATc1/STAT3 binding at chromatin enhancer sites and subsequent regulation of key molecules involved in oncogenic signaling, growth and inflammation. Together, this study supports the relevance of inflammatory transcription factor networks in pancreatic carcinogenesis and provides a theoretical platform for therapeutic targeting of NFATc1 nucleoprotein complexes in PDAC.
Project description:Oncogenic KrasG12D, a driver mutation of pancreatic ductal adenocarcinoma (PDAC), induces neoplastic transformation of acinar cells through acinar-to-ductal metaplasia (ADM). Here, we show that both functional complexes of mTOR (mechanistic target of rapamycin kinase, mTORC1 and mTORC2) are specifically activated in ADM. Murine models uncover that mTORC1 and mTORC2 cooperate to promote KrasG12D-driven ADM development. Proteomic analyses identify Arp2/3 complex, an actin nucleator, as the common downstream effector: mTORC1 is responsible for the protein synthesis of Rac1 and Arp3 while mTORC2 promotes the Arp2/3 complex activity via Akt/Rac1 signalling. Genetic ablation of Arp2/3 complex completely arrests KrasG12D-driven ADM development. The Arp2/3 complex-mediated y-branching of actin network promotes the basolateral spread of filamentous actin, which is indispensable for acinar cells-initiated carcinogenesis. Induced by oncogenic KrasG12D, ADM is a metaplastic phenotype of acinar cells that requires extensive actin rearrangements. mTORC1 and mTORC2, downstream targets of KrasG12D, have well-established oncogenic functions in PDAC development. The actin-related protein 2/3 (Arp2/3) complex is the first identified actin nucleator. Regarded as textbook knowledge, it is activated by EGFR/Rac1 signalling to promote the polymerisation of branched actin filaments from pre-existing filaments in numerous biological contexts. Hereby, we identify that mTORC1 and mTORC2 attain a dual, yet non-redundant, regulatory role in promoting Arp2/3 complex function, which is responsible for generating basolateral filamentous actin in ADM. Thus, the role of Arp2/3 complex fills up the missing gap between putative oncogenic signals and actin dynamics underlying PDAC initiation.
Project description:KRAS-mutant pancreatic ductal adenocarcinoma (PDAC) is highly immunosuppressive and resistant to targeted therapies, immune checkpoint blockade and engineered T cells. In this study, we performed a systematic high throughput combinatorial drug screen and identified a synergistic interaction between the MEK inhibitor trametinib and the multi-kinase inhibitor nintedanib. Using bulk and single-cell RNA sequencing and immunophenotyping, we show that the combination therapy reprograms the immunosuppressive microenvironment and primes cytotoxic and memory T cells to infiltrate the tumors, thereby sensitizing mesenchymal PDAC to PD-L1 inhibition.
Project description:KRAS-mutant pancreatic ductal adenocarcinoma (PDAC) is highly immunosuppressive and resistant to targeted therapies, immune checkpoint blockade and engineered T cells. In this study, we performed a systematic high throughput combinatorial drug screen and identified a synergistic interaction between the MEK inhibitor trametinib and the multi- kinase inhibitor nintedanib. Using single cell RNA sequencing and immunophenotyping, we show that the combination therapy reprograms the immunosuppressive microenvironment and primes cytotoxic and memory T cells to infiltrate the tumors, thereby sensitizing mesenchymal PDAC to PD-L1 inhibition.
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:Pancreatic ductal adenocarcinoma (PDAC) has one of the lowest cancer survival rates. Although KRAS oncogenes are responsible for the initiation of most PDACs, thus far KRAS inhibitors have not changed their clinical outcome. Here, we describe a therapeutic strategy that combines inhibition of three independent signaling nodes involved in downstream (RAF1), upstream (EGFR) and orthogonal (STAT3) KRAS signaling pathways. Genetic elimination and/or pharmacological inhibition/degradation of these independent nodes in orthotopic mouse tumor models results in their complete and durable regression. The efficacy of this therapeutic strategy has also been validated in several patient-derived organoid (PDO) and xenograft (PDX) PDAC tumor models using a combination of a Pan-ERBB inhibitor (Afatinib), a selective STAT3 PROTAC (SD36) and a RAF1 shRNA. Importantly, this triple strategy did not induce significant toxicities. These results open the door to the development of novel targeted therapies for PDAC patients.