EZH2 inhibition confers PIK3CA-driven lung tumors enhanced sensitivity to PI3K inhibition
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE183818 | GEO | 2021/10/12
REPOSITORIES: GEO
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Project description:EZH2 inhibition confers PIK3CA-driven lung tumors enhanced sensitivity to PI3K inhibition
| PRJNA762053 | ENA
Project description:Hyperactivation of the phosphatydil-inositol-3' phosphate kinase (PI3K)/AKT pathway is observed in most NSCLCs, promoting proliferation, migration, invasion and resistance to therapy. AKT can be activated through several mechanisms that include loss of the negative regulator PTEN, activating mutations of the catalytic subunit of PI3K (PIK3CA) and/or mutations of AKT1 itself. However, number and identity of downstream targets of activated PI3K/AKT pathway are poorly defined. To identify the genes that are targets of constitutive PI3K/AKT signalling in lung cancer cells, we performed a comparative transcriptomic analysis of human lung epithelial cells (BEAS-2B) expressing active mutant AKT1 (AKT1-E17K), active mutant PIK3CA (PIK3CA-E545K) or that are silenced for PTEN. For each sample, 500 ng of total RNA were used to synthesize biotinylated cRNA with Illumina RNA Amplification Kit (Ambion, Austin, TX). Synthesis was carried out according to the manufacturersâ instructions. From each sample, technical triplicates were produced and 750 ng cRNA were hybridized for 18h to Human HT-12_V3_0_R1 Expression BeadChips (Illumina, San Diego, CA). Hybridized chips were washed and stained with streptavidin-conjugated Cy3 (GE Healthcare, Milan, Italy). BeadChips were dried and scanned with an Illumina Bead Array Reader (Illumina).
2016-12-01 | E-MTAB-5286 | biostudies-arrayexpress
Project description:Hyperactivation of the PI3K/AKT pathway is observed in most NSCLCs, promoting proliferation, migration and resistance to therapy. AKT can be activated through several mechanisms that include loss of the negative regulator PTEN, activating mutations of the catalytic subunit of the positive regulator phosphatydil-inositol-3â phosphate kinase (PIK3CA) and/or mutations of AKT1 itself. However, whereas the effects of AKT activation on mRNAs and proteins in the cell are fairly clear, the role of miRNAs as downstream targets of activated PI3K/AKT signalling is still poorly defined so far. To identify miRNAs that are targets of constitutive signalling of PI3K/AKT in lung cancer cells, we performed miRNA profiling of human lung epithelial cells expressing active mutant AKT1 (E17K), active mutant PI3KCA (E545K) or that are silenced for PTEN. We identified 28 differentially expressed miRNAs (8 up-regulated, 20 down-regulated) that were common to BEAS-AKT1-E17K, BEAS-PIK3CA-E545K and BEAS-shPTEN cells. Among the 8 up-regulated miRNAs that were common to all the alterations, the miRNA most consistently up-regulated by activation of the PI3K/AKT pathway in BEAS-2B cells was miR-196a. The results reported here demonstrate that miR-196a acts as oncogene downstream the PI3K/AKT pathway, mediating the proliferative, pro-migratory and tumorigenic activity of this pathway in NSCLC cells by targeting FoxO1 and p27 expression. By adoptive expression of miR-196a in BEAS-2B cells, we demonstrated that miR-196a stimulates anchorage-dependent and -independent proliferation, migration and tumorigenicity in BEAS-2B cells. On the other hand, by use of antimir-196a in NCI-H460 cells to silence the endogenous expression of miR-196a, we demonstrate that miR-196a plays a pivotal role in mediating the stimulation of proliferation, migration and tumorigenicity induced by aberrant activation of PI3K/AKT signalling. Accordingly, we found that miR-196a was significantly overexpressed in human NSCLC-derived cell lines (n=6) and primary lung cancer samples (n=28). Finally, based on predicted binding sites for miR-196a by microRNA analysis software, we found that miR-196a affects protein levels of FoxO1 and p27 in NSCLC cells.
2016-06-13 | E-MTAB-4263 | biostudies-arrayexpress
Project description:Activation of the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway is one the most frequent genetic events in human cancer. Therefore, the development of PI3K inhibitors has attracted much attention. We previously described the pyrazolopyrimidine derivative ETP-45658 as a potent inhibitor of PI3K p110α in vitro and in vivo. Here we report the gene expression signatures of MCF7 cells treated with ETP-45658 or the reference PI3K inhibitor PI-103. Both compounds potently inhibited proliferation of a wide range of human cancer cells. ETP-45658 most potently suppressed the growth of PIK3CA (E545K)-mutated MCF7 breast cancer cells. Treatment with ETP-45658 or PI-103 resulted in a time and concentration-dependent decrease in phosphorylation of AKT Ser473 in MCF7 cells. We conducted microarray analysis examining the gene expression profile in MCF7 cells at six hours post ETP-45658 or PI-103 incubation. Both compounds induced the expression of negative cell cycle regulators including Cyclin G2, p27kip1 and ING4 and decreased positive regulators such as Cyclin D1 without significantly affecting the expression of pro-apoptotic genes. We found FOXO transcription factor binding sites over-represented in both up- and down-regulated genes but not in those without significant changes. The expression of the breast cancer tumor suppressor Nischarin was found to be induced by ETP-45658 but not after PI-103 treatment while several genes differentially expressed specifically after ETP-45658 treatment are functionally associated with the focal adhesion pathway. Twelve samples have been analyzed in six different conditions. Two replicates have been included for each condition.
2014-04-08 | E-GEOD-56579 | biostudies-arrayexpress
Project description:The purpose of this study is to examine the efficacy of combined PI3K and CDK4/6 inhibition in lung squamous cell carcinoma (LUSC). LUSC patient-derived xenografts (PDX) are used as preclinical models for this study as they are clinically relevant models and have been shown to recapitulate patient tumor hisology, molecular features and drug response. We have demonstrated using the 1x1x1 drug design that PIK3CA mutation predicts response to PI3K inhibitors. This response can be enhanced by combining CDK4/6 inhibitors with PI3K inhibitors, particularly in PIK3CA mutant PDX. PI3K and CDK4/6 inhibitors may be used in combination in PI3K-activated LUSC.
2019-06-18 | GSE109679 | GEO
Project description:Breast cancer is the second most common cancer type worldwide, representing 25% of all cancers in women. PIK3CA is one of the most frequently mutated genes in breast cancer and mutations result in constitutive activation of the PI3K/mTOR pathway. More than 30 inhibitors against PI3K/mTOR are being tested in clinical trials, however, resistance mechanisms evolve frequently resulting in disease progression. The aim of our study was to investigate PIK3CA collaborative mutations that result in resistance to BYL719, a PI3Kα selective inhibitor. For this purpose, we used a genome-wide PiggyBac transposon mediated mutagenesis screen in a PIK3CAH1047R mutated murine tumor model. One of the tumor suppressor genes discovered was neurofibromin 1 (NF1). Using shRNA-mediated knockdown and CRISPR/Cas9-mediated knockout of NF1 in murine and human PIK3CAH1047R cell lines and a patient derived xenograft organoid model, we found that NF1 loss reduces sensitivity to PI3Kα inhibition. Additionally, we find that loss of NF1 correlates with enhanced glycolysis and lower levels of ROS. Unexpectedly, treatment with NAC sensitized NF1 KO cells to PI3K inhibition in vitro, and in vivo. Global phospho-proteomics indicated that the combination with NAC enhances the inhibitory effect of PI3K inhibition on mTOR signaling, which inhibits proliferation of NF1 KO tumor cells. This raises the interesting possibility to combine PI3K inhibition with NAC especially in NF1 loss tumors
2023-03-30 | PXD034644 | Pride
Project description:ARID1A-mutant bladder cancer is dependent on PI3K signaling and is sensitive to EZH2 and/or PI3K inhibition. Clinical trials in molecularly selected patients should be considered.
2022-08-22 | GSE203033 | GEO
Project description:When co-cultured, HER2 L755S mutant cells are induced to proliferate when coming into close contact with PIK3CA E545K mutant cells We used a microarray to compare transciptome-wide expression levels between HER2 L755S cells, PIK3CA E545K cells, and co-cultures containing both cell types.
2021-03-18 | GSE165065 | GEO
Project description:The RTK/RAS/PI3K pathway is a key driver of tumorigenesis across all cancers, with 90% of Glioblastoma (GBM) tumors exhibiting alterations in this pathway. Among the specific genes in this pathway mutations in PI3K’s catalytic subunit, PIK3CA, are found in 11% of GBM tumors. Sequencing of GBM samples has revealed several known hotspot mutations that drive tumorigenesis in several cancers (E545K, H1047R), as well as a series of 63 in frame mutations (as indexed in COSMIC) that remain largely unclassified. To decode which of these PIK3CA variants function as drivers of GBM, we established an in vivo complementation screening platform for GBM. Our mouse GBM model relies on in utero electroporation (IUE) and CRISPR-Cas9 mediated knockout of NF1, p53, and PTEN (termed 3xCR). Because PTEN catalyzes the reverse reaction of PIK3CA, phosphorylation of PIP2 to PIP3, we complemented loss of PTEN with overexpression of E545K or H1047R, two bona fide hot spot driver mutations of PIK3CA. Both these variants accelerated tumor associated death, demonstrating that known PIK3CA drivers can complement PTEN loss in our system.
2019-10-09 | GSE123519 | GEO
Project description:While growth factor-independent signaling and proliferation are well-established hallmarks of cancer, little is known regarding growth factor-independent changes in gene expression which occur downstream from oncogenes. The PI3K pathway is one of the most commonly misregulated signaling pathways in human cancers. Here, MCF10A cells expressing the two most common PI3K mutations, PIK3CA E545K and H1047R, were used to identify the repertoire of genes altered by oncogenic PI3K mutations following growth factor deprivation. This gene set most closely correlated with gene signatures from claudin-low and basal-like breast tumors, and categorical enrichment analyses suggested that NF-kB target genes were dramatically upregulated by these mutations. An IKKb inhibitor was used to identify the subset of PI3K-driven genes that is NF-kB dependent. Interestingly, virtually all of these NF-kB dependent genes were secreted proteins, suggesting a paracrine role for this gene set. Among these genes was IL-6, a cytokine frequently expressed in tumors which plays a critical role in generating a tumor-promoting microenvironment. Consistent with this, conditioned media from cells expressing the E545K or H1047R mutations led to increased STAT3 activation in recipient THP-1 monocytes or normal epithelial cells in a NF-kB and IL-6-dependent manner. Together, these data describe a PI3K-driven, NF-kB-dependent gene expression profile which may play a critical role in promoting a microenvironment amenable to tumor progression. 39 normal cell lines vs treated cell lines for micorarray analysis
2012-04-30 | E-GEOD-33403 | biostudies-arrayexpress