Gene expression profiling of breast cancer cells with knockdown of PTEN
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE53300 | GEO | 2014/06/30
SECONDARY ACCESSION(S): PRJNA231626
REPOSITORIES: GEO
Similar Datasets
Project description:Phosphoinositide-3-kinase/protein-kinaseB/mammalian target of rapamycin (PI3K/AKT/mTOR) signalling plays an important role in breast cancer (BC). Its interaction with estrogen receptor (ER) signalling becomes more complex and inter-dependent with acquired endocrine resistance. Targeting mTOR combined with endocrine therapy has shown clinical utility, however, a negative feedback-loop exists downstream of PI3K/AKT/mTOR. Direct blockade of AKT together with endocrine therapy may improve BC treatment. AZD5363, a novel pan-AKT kinase catalytic inhibitor, was examined in a panel of ER+ BC cell lines (MCF7, HCC1428, T47D, ZR75.1) adapted to long-term-estrogen-deprivation (LTED) or tamoxifen (TamR). AZD5363 caused a dose-dependent decrease in proliferation in all cell lines tested (GI50<500nM) except HCC1428 and HCC1428-LTED. T47D-LTED and ZR75-LTED were the most sensitive of the lines (GI50~100nM). AZD5363 re-sensitised TamR cells to tamoxifen and acted synergistically with fulvestrant. AZD5363 decreased p-AKT/mTOR targets leading to a reduction in ERα-mediated transcription in a context specific manner and concomitant decrease in recruitment of ER and CREB-binding protein (CBP) to estrogen-response-elements located on the TFF1, PGR and GREB1 promoters. Furthermore, AZD5363 reduced expression of cell-cycle-regulatory proteins. Global gene expression highlighted ERBB2-ERBB3, ERK5 and IGF1 signaling pathways driven by MYC as potential feedback-loops. Combined treatment with AZD5363 and fulvestrant showed synergy in an ER+ patient derived xenograft and delayed tumour progression post-cessation of therapy. These data support the combination of AZD5363 with fulvestrant as a potential therapy for BC that is sensitive or resistant to E-deprivation or tamoxifen and that activated AKT is a determinant of response, supporting the need for clinical evaluation. Cell lines were treated in biological triplicates in the absence of estrogen with or without AZD5363 for 24hours in order to identify gene changes associated with perturbation of AKT signalling
2015-06-29 | E-GEOD-69893 | biostudies-arrayexpress
Project description:Abstract BACKGROUND: The basal-like breast cancer (BLBC) subtype is characterized by positive staining for basal mammary epithelial cytokeratin markers, lack of hormone receptor and HER2 expression, and poor prognosis with currently no approved molecularly-targeted therapies. The oncogenic signaling pathways driving basal-like tumorigenesis are not fully elucidated. METHODS: One hundred sixteen unselected breast tumors were subjected to integrated analysis of phosphoinositide 3-kinase (PI3K) pathway related molecular aberrations by immunohistochemistry, mutation analysis, and gene expression profiling. Incidence and relationships between molecular biomarkers were characterized. Findings for select biomarkers were validated in an independent series. Synergistic cell killing in vitro and in vivo tumor therapy was investigated in breast cancer cell lines and mouse xenograft models, respectively. RESULTS: Sixty-four % of cases had an oncogenic alteration to PIK3CA, PTEN, or INPP4B; when including upstream kinases HER2 and EGFR, 75 % of cases had one or more aberration including 97 % of estrogen receptor (ER)-negative tumors. PTEN-loss was significantly associated to stathmin and EGFR overexpression, positivity for the BLBC markers cytokeratin 5/14, and the BLBC molecular subtype by gene expression profiling, informing a potential therapeutic combination targeting these pathways in BLBC. Combination treatment of BLBC cell lines with the EGFR-inhibitor gefitinib plus the PI3K pathway inhibitor LY294002 was synergistic, and correspondingly, in an in vivo BLBC xenograft mouse model, gefitinib plus PI3K-inhibitor PWT-458 was more effective than either monotherapy and caused tumor regression. CONCLUSIONS: Our study emphasizes the importance of PI3K/PTEN pathway activity in ER-negative and basal-like breast cancer and supports the future clinical evaluation of combining EGFR and PI3K pathway inhibitors for the treatment of BLBC. Gene expression profiles were generated for 95 breast tumors using Agilent Human 44K v5 microarrays following the manufacturer protocol. Stratagene Universal Human Reference RNA was used as the common control sample.
2016-08-21 | E-GEOD-74667 | biostudies-arrayexpress
Project description:Activating mutations in PIK3CA, the gene encoding PI3Kα, are frequently found in estrogen receptor (ER+) breast cancer and the combination of the PI3K inhibitor alpelisib with the anti-ER agent fulvestrant is approved for therapy. We have uncovered a key role for the chromatin modifier KMT2D in regulating the ER-PI3K crosstalk. PI3Kα effectors, AKT and SGK, negatively regulate KMT2D through S1331 phosphorylation. When PI3K is inhibited, this regulatory event is lost, leading to increased chromatin recruitment of KMT2D and an upregulation of ER-dependent transcription. Here we discovered a previously undescribed methylation site on KMT2D, at K1330 directly adjacent to S1331, catalyzed by the lysine methyltransferase SMYD2. SMYD2 loss attenuates alpelisib-induced KMT2D chromatin binding. Accordingly, loss of SMYD2 abrogates alpelisib-induced changes in gene expression, including ER-dependent transcription. Knockdown or pharmacological inhibition of SMYD2 sensitizes breast cancer cells, patient-derived organoids, and tumors to PI3K/AKT inhibition and endocrine therapy in part through KMT2D K1330 methylation. Methyl dead knock-in clones of KMT2D phenocopy many of the effects of SMYD2 inhibition on cell and tumor growth, drug response, and transcriptional output. Together, our findings uncover a regulatory cross-talk between posttranslational modifications that plays an important role in fine-tuning the functions of KMT2D at the chromatin. This provides a rationale for epigenetic therapy using SMYD2 inhibitors in combination with PI3Kα/AKT inhibitors for the treatment of ER+/PIK3CA mutant breast cancer.
2024-05-04 | GSE253958 | GEO
Project description:Activating mutations in PIK3CA, the gene encoding PI3Kα, are frequently found in estrogen receptor (ER+) breast cancer and the combination of the PI3K inhibitor alpelisib with the anti-ER agent fulvestrant is approved for therapy. We have uncovered a key role for the chromatin modifier KMT2D in regulating the ER-PI3K crosstalk. PI3Kα effectors, AKT and SGK, negatively regulate KMT2D through S1331 phosphorylation. When PI3K is inhibited, this regulatory event is lost, leading to increased chromatin recruitment of KMT2D and an upregulation of ER-dependent transcription. Here we discovered a previously undescribed methylation site on KMT2D, at K1330 directly adjacent to S1331, catalyzed by the lysine methyltransferase SMYD2. SMYD2 loss attenuates alpelisib-induced KMT2D chromatin binding. Accordingly, loss of SMYD2 abrogates alpelisib-induced changes in gene expression, including ER-dependent transcription. Knockdown or pharmacological inhibition of SMYD2 sensitizes breast cancer cells, patient-derived organoids, and tumors to PI3K/AKT inhibition and endocrine therapy in part through KMT2D K1330 methylation. Methyl dead knock-in clones of KMT2D phenocopy many of the effects of SMYD2 inhibition on cell and tumor growth, drug response, and transcriptional output. Together, our findings uncover a regulatory cross-talk between posttranslational modifications that plays an important role in fine-tuning the functions of KMT2D at the chromatin. This provides a rationale for epigenetic therapy using SMYD2 inhibitors in combination with PI3Kα/AKT inhibitors for the treatment of ER+/PIK3CA mutant breast cancer.
2024-05-04 | GSE255295 | GEO
Project description:Activating mutations in PIK3CA, the gene encoding PI3Kα, are frequently found in estrogen receptor (ER+) breast cancer and the combination of the PI3K inhibitor alpelisib with the anti-ER agent fulvestrant is approved for therapy. We have uncovered a key role for the chromatin modifier KMT2D in regulating the ER-PI3K crosstalk. PI3Kα effectors, AKT and SGK, negatively regulate KMT2D through S1331 phosphorylation. When PI3K is inhibited, this regulatory event is lost, leading to increased chromatin recruitment of KMT2D and an upregulation of ER-dependent transcription. Here we discovered a previously undescribed methylation site on KMT2D, at K1330 directly adjacent to S1331, catalyzed by the lysine methyltransferase SMYD2. SMYD2 loss attenuates alpelisib-induced KMT2D chromatin binding. Accordingly, loss of SMYD2 abrogates alpelisib-induced changes in gene expression, including ER-dependent transcription. Knockdown or pharmacological inhibition of SMYD2 sensitizes breast cancer cells, patient-derived organoids, and tumors to PI3K/AKT inhibition and endocrine therapy in part through KMT2D K1330 methylation. Methyl dead knock-in clones of KMT2D phenocopy many of the effects of SMYD2 inhibition on cell and tumor growth, drug response, and transcriptional output. Together, our findings uncover a regulatory cross-talk between posttranslational modifications that plays an important role in fine-tuning the functions of KMT2D at the chromatin. This provides a rationale for epigenetic therapy using SMYD2 inhibitors in combination with PI3Kα/AKT inhibitors for the treatment of ER+/PIK3CA mutant breast cancer.
2024-05-04 | GSE253957 | GEO
Project description:Phosphoinositide-3-kinase/protein-kinaseB/mammalian target of rapamycin (PI3K/AKT/mTOR) signalling plays an important role in breast cancer (BC). Its interaction with estrogen receptor (ER) signalling becomes more complex and inter-dependent with acquired endocrine resistance. Targeting mTOR combined with endocrine therapy has shown clinical utility, however, a negative feedback-loop exists downstream of PI3K/AKT/mTOR. Direct blockade of AKT together with endocrine therapy may improve BC treatment. AZD5363, a novel pan-AKT kinase catalytic inhibitor, was examined in a panel of ER+ BC cell lines (MCF7, HCC1428, T47D, ZR75.1) adapted to long-term-estrogen-deprivation (LTED) or tamoxifen (TamR). AZD5363 caused a dose-dependent decrease in proliferation in all cell lines tested (GI50<500nM) except HCC1428 and HCC1428-LTED. T47D-LTED and ZR75-LTED were the most sensitive of the lines (GI50~100nM). AZD5363 re-sensitised TamR cells to tamoxifen and acted synergistically with fulvestrant. AZD5363 decreased p-AKT/mTOR targets leading to a reduction in ERα-mediated transcription in a context specific manner and concomitant decrease in recruitment of ER and CREB-binding protein (CBP) to estrogen-response-elements located on the TFF1, PGR and GREB1 promoters. Furthermore, AZD5363 reduced expression of cell-cycle-regulatory proteins. Global gene expression highlighted ERBB2-ERBB3, ERK5 and IGF1 signaling pathways driven by MYC as potential feedback-loops. Combined treatment with AZD5363 and fulvestrant showed synergy in an ER+ patient derived xenograft and delayed tumour progression post-cessation of therapy. These data support the combination of AZD5363 with fulvestrant as a potential therapy for BC that is sensitive or resistant to E-deprivation or tamoxifen and that activated AKT is a determinant of response, supporting the need for clinical evaluation.
2015-06-29 | GSE69893 | GEO
Project description:The high frequency of aberrant PI3K pathway activation in hormone receptor-positive (HR+) breast cancer has led to the development, clinical testing, and approval of the p110a-selective PI3K inhibitor alpelisib. The limited clinical efficacy of alpelisib and other PI3K inhibitors is partially attributed to the functional antagonism between PI3K and estrogen receptor (ER) signaling, which is mitigated via combined PI3K inhibition and endocrine therapy. We and others have previously demonstrated chromatin-associated mechanisms by which PI3K supports cancer development and antagonizes ER signaling through the modulation of the H3K4 methylation axis; inhibition of KDM5A promoter H3K4 demethylation and KMT2D/MLL4-directed enhancer H3K4 methylation. Here we show that inhibition of the H3K4 histone methyltransferase MLL1 in combination with PI3K inhibition impairs HR+ breast cancer clonogenicity and cell proliferation. While combined PI3K/MLL1 inhibition reduces PI3K/AKT signaling and H3K4 methylation, MLL1 inhibition increases PI3K/AKT signaling and dysregulates the expression of processes that lead to AKT activation. These data reveal a feedback loop between MLL1 and AKT whereby MLL1 inhibition reactivates AKT. We show that combined PI3K and MLL1 inhibition synergizes to cause cell death in in vitro and in vivo models of HR+ breast cancer, which is enhanced by the additional genetic ablation of the H3K4 methyltransferase and AKT target KMT2D/MLL4. Together, our data provide evidence of a feedback mechanism connecting histone methylation with AKT and may support the preclinical development and testing of pan-MLL inhibitors.
2022-10-01 | GSE214331 | GEO
Project description:The high frequency of aberrant PI3K pathway activation in hormone receptor-positive (HR+) breast cancer has led to the development, clinical testing, and approval of the p110a-selective PI3K inhibitor alpelisib. The limited clinical efficacy of alpelisib and other PI3K inhibitors is partially attributed to the functional antagonism between PI3K and estrogen receptor (ER) signaling, which is mitigated via combined PI3K inhibition and endocrine therapy. We and others have previously demonstrated chromatin-associated mechanisms by which PI3K supports cancer development and antagonizes ER signaling through the modulation of the H3K4 methylation axis; inhibition of KDM5A promoter H3K4 demethylation and KMT2D/MLL4-directed enhancer H3K4 methylation. Here we show that inhibition of the H3K4 histone methyltransferase MLL1 in combination with PI3K inhibition impairs HR+ breast cancer clonogenicity and cell proliferation. While combined PI3K/MLL1 inhibition reduces PI3K/AKT signaling and H3K4 methylation, MLL1 inhibition increases PI3K/AKT signaling and dysregulates the expression of processes that lead to AKT activation. These data reveal a feedback loop between MLL1 and AKT whereby MLL1 inhibition reactivates AKT. We show that combined PI3K and MLL1 inhibition synergizes to cause cell death in in vitro and in vivo models of HR+ breast cancer, which is enhanced by the additional genetic ablation of the H3K4 methyltransferase and AKT target KMT2D/MLL4. Together, our data provide evidence of a feedback mechanism connecting histone methylation with AKT and may support the preclinical development and testing of pan-MLL inhibitors.
2022-10-01 | GSE214329 | GEO
Project description:Mutations in ARID1A, a subunit of the SWI/SNF chromatin remodelling complex, are the most common somatic alteration of the SWI/SNF complex across all cancers including oestrogen receptor positive (ER)+ breast cancer. We have recently reported that ARID1A inactivating mutations are present at a high frequency in advanced endocrine resistant ER+ breast cancer. In parallel, to identify mechanisms of resistance to endocrine therapy in breast cancer, we performed an epigenome CRISPR/CAS9 knockout screen that identified ARID1A as the top candidate whose loss determines resistance to the ER degrader fulvestrant. ARID1A knockout cells were found to be less responsive to endocrine therapy compared to intact ARID1A cells in vitro and in vivo. This set of observations in patients’ tumours and in unbiased CRISPR screens led us to explore the epigenetic mechanisms whereby loss of ARID1A may influence breast cancer progression and/or endocrine therapy resistance. ARID1A disruption in ER+ breast cancer cells led to widespread changes in chromatin accessibility converging on loss of the master transcription factors (TFs) that regulate gene expression programs critical for luminal lineage identity. Global transcriptome profiling of ARID1A knockout cell lines and patient samples harbouring ARID1A inactivating mutations revealed an enrichment for basal-like gene expression signatures. The state of increased cellular plasticity of luminal cells that acquire a basal-like phenotype upon ARID1A inactivation is enabled by loss of ARID1A-dependent SWI/SNF complex targeting to genomic sites of the major luminal-lineage determining transcription factors including ER, FOXA1, and GATA3. We also show that ARID1A regulates genome-wide ER-chromatin interactions and ER-dependent transcription. Altogether, we uncover a critical role for ARID1A in the determination of breast luminal cell identity and endocrine therapeutic response in ER+ breast cancer.
2019-11-13 | GSE140185 | GEO
Project description:Mutations in ARID1A, a subunit of the SWI/SNF chromatin remodelling complex, are the most common somatic alteration of the SWI/SNF complex across all cancers including oestrogen receptor positive (ER)+ breast cancer. We have recently reported that ARID1A inactivating mutations are present at a high frequency in advanced endocrine resistant ER+ breast cancer. In parallel, to identify mechanisms of resistance to endocrine therapy in breast cancer, we performed an epigenome CRISPR/CAS9 knockout screen that identified ARID1A as the top candidate whose loss determines resistance to the ER degrader fulvestrant. ARID1A knockout cells were found to be less responsive to endocrine therapy compared to intact ARID1A cells in vitro and in vivo. This set of observations in patients’ tumours and in unbiased CRISPR screens led us to explore the epigenetic mechanisms whereby loss of ARID1A may influence breast cancer progression and/or endocrine therapy resistance. ARID1A disruption in ER+ breast cancer cells led to widespread changes in chromatin accessibility converging on loss of the master transcription factors (TFs) that regulate gene expression programs critical for luminal lineage identity. Global transcriptome profiling of ARID1A knockout cell lines and patient samples harbouring ARID1A inactivating mutations revealed an enrichment for basal-like gene expression signatures. The state of increased cellular plasticity of luminal cells that acquire a basal-like phenotype upon ARID1A inactivation is enabled by loss of ARID1A-dependent SWI/SNF complex targeting to genomic sites of the major luminal-lineage determining transcription factors including ER, FOXA1, and GATA3. We also show that ARID1A regulates genome-wide ER-chromatin interactions and ER-dependent transcription. Altogether, we uncover a critical role for ARID1A in the determination of breast luminal cell identity and endocrine therapeutic response in ER+ breast cancer.
2019-11-13 | GSE124225 | GEO