Project description:Pancreatic ductal adenocarcinoma (PDAC) is a nearly uniformly lethal malignancy, with most patients facing an adverse clinical outcome. Given the pivotal role of aberrant Notch signaling in the initiation and progression of PDAC, we investigated the effect of MRK-003, a potent and selective γ-secretase inhibitor, in preclinical PDAC models. We used a panel of human PDAC cell lines, as well as patient-derived PDAC xenografts, to determine whether pharmacological targeting of the Notch pathway could inhibit pancreatic tumor growth and potentiate gemcitabine sensitivity. In vitro, MRK-003 treatment downregulated the canonical Notch target gene Hes-1, significantly inhibited anchorage independent growth, and reduced the subset of CD44+CD24+ and aldehyde dehydrogenase (ALDH)+ cells that have been attributed with tumor initiating capacity. Ex vivo pretreatment of PDAC cells with MRK-003 in culture significantly inhibited the subsequent engraftment in immunocompromised mice. In vivo, MRK-003 monotherapy significantly blocked tumor growth in 5 of 9 (56%) patient-derived PDAC xenografts. Moreover, a combination of MRK-003 and gemcitabine showed enhanced antitumor effects compared to gemcitabine alone in 4 of 9 (44%) PDAC xenografts. Baseline gene expression analysis of the treated xenografts indicated that upregulation of nuclear factor kappa B (NFκB) pathway components was associated with the sensitivity to single MRK-003, while upregulation in B-cell receptor (BCR) signaling and nuclear factor erythroid-derived 2-like 2 (NRF2) pathway correlated with response to the combination of MRK-003 with gemcitabine. The preclinical findings presented here provide further rationale for small molecule inhibition of Notch signaling as a therapeutic strategy in PDAC. Pancreatic ductal adenocarcinoma xenografts were grown in Athymic Nude-Foxn1nu mice. RNA was extracted and profiled in Affymetrix platform to identify genes correlating with sensitivity to MRK-003
Project description:Pancreatic ductal adenocarcinoma (PDAC) is a nearly uniformly lethal malignancy, with most patients facing an adverse clinical outcome. Given the pivotal role of aberrant Notch signaling in the initiation and progression of PDAC, we investigated the effect of MRK-003, a potent and selective γ-secretase inhibitor, in preclinical PDAC models. We used a panel of human PDAC cell lines, as well as patient-derived PDAC xenografts, to determine whether pharmacological targeting of the Notch pathway could inhibit pancreatic tumor growth and potentiate gemcitabine sensitivity. In vitro, MRK-003 treatment downregulated the canonical Notch target gene Hes-1, significantly inhibited anchorage independent growth, and reduced the subset of CD44+CD24+ and aldehyde dehydrogenase (ALDH)+ cells that have been attributed with tumor initiating capacity. Ex vivo pretreatment of PDAC cells with MRK-003 in culture significantly inhibited the subsequent engraftment in immunocompromised mice. In vivo, MRK-003 monotherapy significantly blocked tumor growth in 5 of 9 (56%) patient-derived PDAC xenografts. Moreover, a combination of MRK-003 and gemcitabine showed enhanced antitumor effects compared to gemcitabine alone in 4 of 9 (44%) PDAC xenografts. Baseline gene expression analysis of the treated xenografts indicated that upregulation of nuclear factor kappa B (NFκB) pathway components was associated with the sensitivity to single MRK-003, while upregulation in B-cell receptor (BCR) signaling and nuclear factor erythroid-derived 2-like 2 (NRF2) pathway correlated with response to the combination of MRK-003 with gemcitabine. The preclinical findings presented here provide further rationale for small molecule inhibition of Notch signaling as a therapeutic strategy in PDAC.
Project description:This randomized phase I/II clinical trial is studying the side effects and best dose of gamma-secretase/notch signalling pathway inhibitor RO4929097 when given together with vismodegib and to see how well they work in treating patients with advanced or metastatic sarcoma. Vismodegib may slow the growth of tumor cells. Gamma-secretase/notch signalling pathway inhibitor RO4929097 may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Giving vismodegib together with gamma-secretase/notch signalling pathway inhibitor RO4929097 may be an effective treatment for sarcoma.
Project description:Transcriptional profiling of MC3T3-E1 osteoblasts that were flow cytometry-separated from cocultures with control or Jagged1-overexpressing tumor cells and treated with either DMSO control or 1μM MRK-003 (gamma-secretase inhibitor).
Project description:Lineage-negative thymocytes were cultured on OP9-DL1 stromal cells for 16h in the presence of DMSO or the gamma secretase inhibitor MRK-003. DN3 cells cells were then sorted and their transcriptome analyzed.
Project description:Lineage-negative thymocytes were cultured on OP9-DL1 stromal cells for 16h in the presence of DMSO or the gamma secretase inhibitor MRK-003. DN3 cells cells were then sorted and their transcriptome analyzed. 8 samples
Project description:Transcriptional profiling of MC3T3-E1 osteoblasts that were flow cytometry-separated from cocultures with control or Jagged1-overexpressing tumor cells and treated with either DMSO control or 1μM MRK-003 (gamma-secretase inhibitor). One cell line (MC3T3-E1) cells: four different experimental conditions: cultured with (1) control tumor cells + DMSO; (2) Jagged1-overexpressing tumor cells + DMSO; (3) control tumor cells + MRK-003; (4) Jagged1-overexpressing tumor cells + MRK-003. Each experiment has two biological replicates. Total, 8 samples.
Project description:T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematologic cancer frequently associated with activating mutations in NOTCH1. Early studies identified NOTCH1 as an attractive therapeutic target for the treatment of T-ALL through the use of gamma-secretase inhibitors (GSIs). Here, we characterized the interaction between PF-03084014, a clinically-relevant GSI, and dexamethasone in preclinical models of glucocorticoid-resistant T-ALL. Combination treatment of the GSI PF-03084014 with glucocorticoids induced a synergistic antileukemic effect in human T-ALL cell lines and primary human T-ALL patient samples. Molecular characterization of the response to PF-03084014 plus glucocorticoids through gene expression profiling revealed transcriptional upregulation of the glucocorticoid receptor as the mechanism mediating the enhanced glucocorticoid response. Moreover, treatment with PF-03084014 and glucocorticoids in combination was highly efficacious in vivo, with enhanced reduction of tumor burden in a xenograft model of T-ALL. Finally, glucocorticoid treatment was highly effective at reversing PF-03084014-induced gastrointestinal toxicity via inhibition of goblet cell metaplasia. These results suggest that combination of PF-03084014 treatment with glucocorticoids may be well-tolerated and highly active for the treatment of glucorticoid-resistant T-ALL. Duplicate samples of the CUTLL1 T-ALL cell line were treated with vehicle only (DMSO), the gamma-secretase inhibitor PF-03084014 (1 microM), dexamethasone (1 microM), or PF-03084014 (1 microM). plus dexamethasone (1 microM) for 48 hours. Gene expression profiling was analyzed to identify gene expression signatures assocuated with glucocorticoid treatment (dexamethasone), inhibition of NOTCH1 by gamma secretase inhibitor (PF-03084014) or the combination of both treatments.
Project description:We have investigated the role of the Notch pathway in the generation and maintenance of KrasG12V-driven non-small cell lung carcinomas (NSCLCs). We demonstrate by genetic means that γ-secretase and Rbpj activities are both essential in the formation of NSCLCs. Interestingly, pharmacologic treatment of mice carrying endogenous NSCLCs with a γ-secretase inhibitor (GSI) blocks cancer growth and induces partial regression. Treated cancers show a reduction in Hes1 levels, reduced phosphorylated Erk, decreased proliferation and higher apoptosis. We demonstrate that HES1 directly binds and represses the promoter of DUSP1, a dual phosphatase with activity against phospho-ERK, and this repression is relieved by GSI treatment both in mouse and human NSCLCs. Our data provide proof for the in vivo therapeutic potential of γ-secretase inhibitors in primary NSCLCs and provide a mechanistic explanation for its therapeutical effect. We have included 6 samples. 3 with vehicle and 3 with the gamma-secretase inhibitor DAPT and we compare both groups.
Project description:Desmoid tumors (DTs) are rare mesenchymal monoclonal lesions that have a high risk of local recurrence but lack metastatic potential. Since the Notch pathway appears to be important in the carcinogenesis of several tumor types, in the past few years γ-secretase inhibitors (GSIs) have emerged as a potential therapeutic treatment by inhibiting cancer cell Notch signaling through NICD cleavage blockade. To investigate the antitumor effect of PF-03084014, a γ-secretase inhibitor, in DT models, cells treated with PF-03084014 were characterized by gene array analysis.