Project description:The goal of this experiment was to understand the changes in gene expression in the human basal-like breast cancer cell line HCC1143 following treatment with the MEK inhibitor Trametinib (T), PI3K/mTOR inhibitor BEZ235 (B), the BET inhibition JQ1 (JQ), Trametinib + JQ1 (TJ), or BEZ235 + JQ1(BJ), compared to a DMSO control (D). Samples were treated for 72hr and run in triplicate.
Project description:Human basal-like breast cancer cell line HCC1143 treated with BET inhibitor JQ1 in combination with MEK inhibitor Trametinib or PI3K/mTOR inhibitor BEZ235
Project description:In an effort to understand the mechanisms of acquired resistance to BRAF inhibitors, we isolated clones that acquired resistance to the BRAF inhibitor GSK2118436 derived from the A375 BRAF V600E mutant melanoma cell line. This resistance clones acquired mutations in NRAS and MEK1. One clones, 16R6-4, acquired two mutations in NRAS – Q61K and A146T. Proliferation and western blot analyses demonstrated that these clones were insensitive to single agent GSK2118436 or GSK1120212 (an allosteric MEK inhibitor) but were sensitive to the combination of GSK2118436 and GSK1120212. To further characterize this combination, global transcriptomic analysis was performed in A375 and 16R6-4 after 24 hour treatment with GSK2118436, GSK1120212 or the combination of GSK2118436 and GSK1120212. This data set was published in Molecular Cancer Therapeutics with the title “Combined inhibition of BRAF and MEK, BRAF and PI3K/mTOR, or MEK and PI3K/mTOR overcomes acquired resistance to the BRAF inhibitor GSK2118436, mediated by NRAS or MEK mutations” by Greger, J.G., et.al. A375 and 16R6-4 (an A375 derived GSK2118436 resistance clone) were treated for 24 hours with 0.1 micromolar GSK2118436, 1 micromolar GSK2118436, 0.01 micromolar GSK1120212, 0.1 micromolar GSK2118436 + 0.01 micromolar GSK1120212, or 1 micromolar GSK2118436 + 0.01 micromolar GSK1120212.
Project description:Phosphatidylinositol-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway activation contributes to mantle cell lymphoma (MCL) pathogenesis and drug resistance. However, the use of mTOR inhibitors as single agents have shown limited clinical efficacy in relation with drug activation of feedback loops. Selective PI3K inhibition or dual PI3K/mTOR catalytic inhibition are different therapeutic approaches developed to achieve effective pathway blockage. Here, we evaluated the antitumor activity of a mTOR inhibitor, a pan-PI3K inhibitor and a dual PI3K/mTOR inhibitor in primary MCL cells. We found that dual PI3K/mTOR inhibitor modulated angiogenesis, tumor invasiveness and cytokine signaling compared to a mTOR inhibitor and a pan-PI3K inhibitor in MCL. We used microarrays to compare the effect of these three compounds in MCL and identified distinct classes of down-regulated genes modulated by each compound. Global RNA expression in primary cells from two MCL patients treated with a mTOR inhibitor, a pan-PI3K inhibitor and a dual PI3K/mTOR inhibitor for 8 hours
Project description:We performed single-cell combinatorial indexing ATAC-seq on the basal-like TNBC cell line HCC1143 under MEK, PI3K, BET and combination treatments as well as DMSO controls
Project description:Activation of the PI3K pathway in estrogen receptor α (ER)-positive (+) breast cancer is associated with reduced ER expression and activity, luminal B subtype, and poor outcome. PTEN is a negative regulator of the PI3K pathway typically lost in ER-negative (-) breast cancer. To clarify the effect of PTEN down-regulation on the response of ER+/HER2- breast cancer to endocrine therapy, we established reduced PTEN cell models using inducible knockdown. We found that only moderate PTEN reduction is sufficient to enhance PI3K signaling, generate a gene signature associated with luminal B subtype, and cause endocrine resistance. Combining endocrine therapy with mTOR, AKT, or MEK inhibitors improves antitumor activity, but the efficacy varies by type of endocrine therapy and the specific inhibitor. Fulvestrant plus an AKT inhibitor is the most potent combination when PTEN is reduced, inducing apoptosis and tumor regression. This combination deserves further study in patients with PI3K pathway activation.
Project description:Anticancer drug development is an inefficient process, with potential therapeutics demonstrating a high attrition rate due to lack of efficacy in Phase II/III testing. In an effort to develop improved pre-clinical predictors of efficacy, we and others have turned to testing in genetically engineered murine models (GEMMs) of cancer, which may offer some advantages to in vitro and xenograft systems. Specifically, we assessed the activity of 16 treatment regimens in a Ras-driven, Ink4a/Arf-deficient melanoma GEMM. Like human RAS-mutant melanoma, this GEMM was refractory to standard chemotherapy and single-agent small molecule therapies. Only one regimen exhibited significant anti-tumor activity in this model: combined treatment with AZD6244 (MEK inhibitor) and BEZ235 (dual PI3K/mTOR inhibitor), which produced marked tumor regression and improved survival. Given the surprising activity of the “AZD/BEZ” combination in a melanoma GEMM, we next tested this regimen in a Ras-driven orthotopic-transplant model of “claudin-low” breast cancer, which shares some gene expression features with melanoma. The AZD/BEZ regimen also exhibited significant activity in this related Ras-driven model, leading us to testing in even more diverse GEMMs of basal-like and luminal breast cancer. The AZD/BEZ combination was highly active in each of these distinct breast models, demonstrating equal or greater efficacy compared to any other regimen tested in studies of over 700 tumor-bearing mice. This regimen even exhibited activity in tumors selected for resistance to another effective chemotherapy agent, lapatinib, in HER2+ models. These results demonstrate the utility of credentialed murine models for large-scale efficacy testing of diverse anti-cancer regimens, and predict combinations of PI3K/mTOR and MEK inhibitors will demonstrate anti-tumor activity in a wide-range of human malignancies. 16 array samples
Project description:This research trial is testing a combination of two experimental drugs, MSC1936369B (Mitogen-activated protein extracellular signal-regulated kinase (MEK) Inhibitor) and SAR245409 (Phosphatidylinositol 3-kinase (Pi3K)/Mammalian Target of Rapamycin (mTOR) inhibitor), in the treatment of locally advanced or metastatic solid tumors. The primary purpose of the study is to determine the maximum tolerated dose of the drug combination.
Project description:In an effort to understand the mechanisms of acquired resistance to BRAF inhibitors, we isolated clones that acquired resistance to the BRAF inhibitor GSK2118436 derived from the A375 BRAF V600E mutant melanoma cell line. This resistance clones acquired mutations in NRAS and MEK1. One clones, 16R6-4, acquired two mutations in NRAS – Q61K and A146T. Proliferation and western blot analyses demonstrated that these clones were insensitive to single agent GSK2118436 or GSK1120212 (an allosteric MEK inhibitor) but were sensitive to the combination of GSK2118436 and GSK1120212. To further characterize this combination, global transcriptomic analysis was performed in A375 and 16R6-4 after 24 hour treatment with GSK2118436, GSK1120212 or the combination of GSK2118436 and GSK1120212. This data set was published in Molecular Cancer Therapeutics with the title “Combined inhibition of BRAF and MEK, BRAF and PI3K/mTOR, or MEK and PI3K/mTOR overcomes acquired resistance to the BRAF inhibitor GSK2118436, mediated by NRAS or MEK mutations” by Greger, J.G., et.al.
Project description:Copy number profiling of 92 human lung tumors on Affymetrix 100K SNP arrays was conducted in order to assess the interaction of common genomic alterations with response to targeted anti-cancer therapeutics. Class 1 phosphatidylinositol 3' kinase (PI3K) plays a major role in cell proliferation and survival in a wide variety of human cancers. Here we investigate biomarker strategies for PI3K pathway inhibitors in non-small-cell lung cancer (NSCLC). Molecular profiling of NSCLC tumor samples showed that copy number gains in PIK3CA and total loss of PTEN protein were common in squamous cell carcinoma samples, whereas LKB1 loss and mutations in KRAS and EGFR were common in adenocarcinomas. A panel of NSCLC cell lines characterized for alterations in the PI3K pathway was screened with PI3K and dual PI3K/mTOR inhibitors to assess the preclinical predictive value of candidate biomarkers. Cell lines harboring pathway alterations (RTK activation, PI3K mutation or amplification, PTEN loss) were exquisitely sensitive to the PI3K inhibitor GDC-0941. A dual PI3K/mTOR inhibitor had broader activity across the cell line panel and in tumor xenografts. The combination of GDC-0941 with paclitaxel, erlotinib, or a MEK inhibitor had greater effects on cell viability than PI3K inhibition alone. CONCLUSIONS: Candidate biomarkers for PI3K inhibitors have predictive value in preclinical models and show histology-specific alterations in primary tumors, suggesting that distinct biomarker strategies may be required in squamous compared with non-squamous NSCLC patient populations. Lung tumors were profiled on Affymetrix GeneChip Mapping 100K Set Arrays Tumor samples were profiled for copy number without any treatment of the tumor.