E-GEOD-56579
Ontology highlight
ABSTRACT:
OTHER RELATED OMICS DATASETS IN: PRJNA243974
PROVIDER: E-GEOD-56579 | ExpressionAtlas | 2015-08-25
REPOSITORIES: ExpressionAtlas
Similar Datasets
Project description:Gene expression profiling upon PI3K inhibition using different inhibitors
| PRJNA243974 | ENA
Project description:The PI3K/mammalian target of rapamycin (mTOR) pathway is dysregulated in over 50% of human GBM but remains a challenging clinical target. Inhibitors against PI3K/mTOR mediators have limited clinical efficacy as single agents. Gene expression profiling after PI3K/mTOR inhibition treatment was analyzed by Affymetrix microarrays.
2016-05-20 | GSE79316 | GEO
Project description:Activating mutations of PIK3CA are the most frequent genomic alterations in estrogen receptor (ER)-positive breast tumors and selective PI3Kα inhibitors are in clinical development. The activity of these agents, however, is not homogenous and only a fraction of patients bearing PIK3CA-mutant ER-positive tumors benefit from single agent administration. Searching for mechanisms of resistance, we observed that suppression of PI3K signaling with different agents results in induction of ER-dependent transcriptional activity as demonstrated by changes in expression in genes containing ER binding sites, enhanced ER transcription and increased occupancy by the ER of promoter regions of upregulated genes. Furthermore, expression of ESR1 mRNA and ER protein levels themselves were also increased upon PI3K inhibition. These changes in gene expression were confirmed in vivo in xenograft and patient derived models and in tumors from patients undergoing treatment with the PI3Kα inhibitor BYL719. The observed effects on transcription were enhanced by the addition of estradiol and suppressed by the anti-ER therapies fulvestrant and tamoxifen. Fulvestrant markedly sensitized ER-positive tumors to PI3Kα inhibition. We propose that increased ER transcriptional activity may be a compensatory mechanism that limits the activity of PI3K inhibitors and that combined PI3K and ER inhibition is a rational approach to target these tumors. The aim of our study was to explore the mechanism by which combination of PI3K pathway inhibitors and estrogen receptor function blockade results in superior antitumor activity. We aimed to evaluate whether changes in ER function were influencing the clinical response to anti-PI3K therapy in ER-positive breast tumors that harbor PI3K pathway activation. For this purpose, we planned to use various specific PI3K inhibitors, namely: BYL719 (p110α specific catalytic inhibitor), GDC0941 (pan-PI3K inhibitor), GDC0032 and BAY80-6946 (p110sparing PI3K inhibitors) in a panel of ER-positive breast cancer cell lines and xenografts that harbor PIK3CA activating mutations. We also used MK2206 (pan-AKT allosteric inhibitor) to inhibit the PI3K pathway in ER-positive cell lines which activate this pathway through PTEN loss. Finally, in order to evaluate the role of ER up-regulation as a pro-survival signal in our in vitro and in vivo models, we planned to use the selective ER modulator 4-hydroxy-tamoxifen (4-OHT) and degrader fulvestrant. For the in vivo experiments, the number of animals in each group was calculated to measure a 25% difference between the means of placebo and treatment groups with a power of 80% and a p value of 0.01. Host mice carrying xenografts were randomly and equally assigned to either control or treatment groups. Animal experiments were conducted in a controlled and non-blinded manner. Moreover, we evaluated by means of RNAseq gene expression changes breast cancer patients that underwent BYL719 based therapy to validate our in vitro findings in terms of ER expression. In vitro experiments were performed at least two times and at least in triplicate for each replica.
2015-04-29 | E-GEOD-64033 | biostudies-arrayexpress
Project description:Mutations in PIK3CA, the gene encoding the p110α subunit of PI3K, induce transformation of mammary epithelial cells (MEC). Studies suggest the transforming action of mutant PIK3CA requires binding to activated receptor tyrosine kinases or adaptors. We examined in transgenic mice if ErbB3, a powerful activator of PI3K, is required for mutant PIK3CA-mediated MEC transformation. ErbB3 loss delayed PIK3CAH1047R-dependent mammary gland hyperplasia, but tumor latency, gene expression and markers of PI3K signaling were unaffected. In ErbB3-deficient tumors, mutant PI3K remained associated with other tyrosine phosphorylated adaptors, potentially explaining the dispensability of ErbB3 for tumorigenicity and PI3K activity. Combined inhibition of ErbB RTKs and PI3K with lapatinib and the p110α inhibitor BYL719, respectively, reduced PIK3CAH1047R-dependent tumor growth and PI3K signaling more potently than the p110α inhibitor alone. In human breast cancer cells harboring PIK3CAH1047R, the combination with BYL719 and an ErbB3 inhibitor synergistically inhibited tumor growth and P-Akt. These data suggest that basal tumor growth and PI3K signaling do not depend on ErbB RTKs in PIK3CAH1047R-expressing tumors. However, upon inhibition of p110α, these receptors limit the action of PI3K inhibitors potentially explaining the more potent effect of the combination against PI3K-mutant cancers. reference x sample
2013-06-20 | E-GEOD-43037 | biostudies-arrayexpress
Project description:Activating mutations of PIK3CA are the most frequent genomic alterations in estrogen receptor (ER)-positive breast tumors and selective PI3Kα inhibitors are in clinical development. The activity of these agents, however, is not homogenous and only a fraction of patients bearing PIK3CA-mutant ER-positive tumors benefit from single agent administration. Searching for mechanisms of resistance, we observed that suppression of PI3K signaling with different agents results in induction of ER-dependent transcriptional activity as demonstrated by changes in expression in genes containing ER binding sites, enhanced ER transcription and increased occupancy by the ER of promoter regions of upregulated genes. Furthermore, expression of ESR1 mRNA and ER protein levels themselves were also increased upon PI3K inhibition. These changes in gene expression were confirmed in vivo in xenograft and patient derived models and in tumors from patients undergoing treatment with the PI3Kα inhibitor BYL719. The observed effects on transcription were enhanced by the addition of estradiol and suppressed by the anti-ER therapies fulvestrant and tamoxifen. Fulvestrant markedly sensitized ER-positive tumors to PI3Kα inhibition. We propose that increased ER transcriptional activity may be a compensatory mechanism that limits the activity of PI3K inhibitors and that combined PI3K and ER inhibition is a rational approach to target these tumors.
2015-04-29 | GSE64033 | GEO
Project description:Fang L, Ford-Roshon D, Russo M, O'Brien C, Xiong X, Gurjao C, Grandclaudon M, Raghavan S, Corsello SM, Carr SA, Udeshi ND, Berstler J, Sicinska E, Ng K, Giannakis M. 2022.
The RNF43_p.G659fs mutation occurs frequently in colorectal cancer, but its function remains poorly understood and there are no specific therapies directed against this alteration. In this study, we find that RNF43_p.G659fs promotes cell growth independent of Wnt signaling. We perform a drug repurposing library screen and discover that cells with RNF43_G659 mutations are selectively killed by inhibition of PI3K signaling. PI3K/mTOR inhibitors yield promising antitumor activity in RNF43659mut isogenic cell lines and xenograft models, as well as in patient-derived organoids harboring RNF43_p.G659fs mutations. We find that RNF43659mut binds p85 leading to increased PI3K signaling through p85 ubiquitination and degradation. Additionally, RNA-sequencing of RNF43659mut isogenic cells reveals decreased interferon response gene expression, that is reversed by PI3K/mTOR inhibition, suggesting that RNF43659mut may alter tumor immunity. Our findings suggest a therapeutic application for PI3K/mTOR inhibitors in treating RNF43_p.G659fs mutant cancers.
2022-04-29 | MSV000089343 | MassIVE
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
2013-12-14 | E-GEOD-53309 | biostudies-arrayexpress
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.
2013-01-10 | E-GEOD-39793 | biostudies-arrayexpress
Project description:We hypothesised that PI3K and BET inhibition would synergise in the context of MYC-dysregulation and overcome resistance to single-target inhibition. We then synthesised a series of chimeric molecules linking BET- and PI3K-selective pharmacophores, including our lead molecule, 18D(S). RNA-Seq profiling following acute 18D(S) treatment demonstrated robust transcriptional modulation with concomitant BET and PI3K inhibitory signatures. Our data provides proof-of-concept for the design of potent PI3K- and BET-inhibitors, providing ‘synergy in a single molecule’.
2023-09-07 | GSE242465 | GEO
Project description:We hypothesised that PI3K and BET inhibition would synergise in the context of MYC-dysregulation and overcome resistance to single-target inhibition. We then synthesised a series of chimeric molecules linking BET- and PI3K-selective pharmacophores, including our lead molecule, 18D(S). RNA-Seq profiling following acute 18D(S) treatment demonstrated robust transcriptional modulation with concomitant BET and PI3K inhibitory signatures. Our data provides proof-of-concept for the design of potent PI3K- and BET-inhibitors, providing ‘synergy in a single molecule’.
2023-08-14 | GSE188442 | GEO