Browse
Submit Data
Databases
API
Help

Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

48 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Affymetrix SNP array data for mammary tumors that recurred after inactivation of the oncogenic PIK3CA-H1047R

ABSTRACT: Gain-of-function mutation of PIK3CA represents one of the most common oncogenic events in human malignancy, making PI3K an attractive target for cancer therapy. Despite the great promise of targeted therapy, drug resistance is likely to develop, causing treatment failure. To elucidate resistance mechanisms to PI3K-targeted therapy, we constructed a mouse model of breast cancer conditionally expressing PIK3CA-H1047R. Surprisingly, the majority of mammary tumors induced by PIK3CA-H1047R expression recurred following PIK3CA-H1047R inactivation. Genomic analyses of recurrent tumors revealed multiple lesions, including spontaneous focal amplification of c-Met or c-Myc. While amplification of c-Met allowed tumor survival dependent on activation of endogenous PI3K, tumors with amplification of c-Myc become independent of the PI3K pathway. Functional analyses further demonstrated that c-Myc contributed to tumors’ independence of oncogene and resistance to PI3K inhibition. Together, our data suggest that MYC elevation in tumors may be a potential mechanism conferring resistance to current PI3K-targeted therapies. Affymetrix SNP array analysis was performed with Mouse Diversity Genotyping Arrays (Affymetrix) on genomic DNA extracted from frozen biopsies of 6 recurrent mouse mammary tumor samples. Copy number analysis was performed for the mouse mammary tumors using genomic DNA from normal mammary tissue as the reference for copy number inference.

ORGANISM(S): Mus musculus

SUBMITTER: jean zhao

PROVIDER: E-GEOD-27691 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Json Xml

Similar Datasets

Affymetrix SNP array data for mammary tumors that recurred after inactivation of the oncogenic PIK3CA-H1047R

Project description:Gain-of-function mutation of PIK3CA represents one of the most common oncogenic events in human malignancy, making PI3K an attractive target for cancer therapy. Despite the great promise of targeted therapy, drug resistance is likely to develop, causing treatment failure. To elucidate resistance mechanisms to PI3K-targeted therapy, we constructed a mouse model of breast cancer conditionally expressing PIK3CA-H1047R. Surprisingly, the majority of mammary tumors induced by PIK3CA-H1047R expression recurred following PIK3CA-H1047R inactivation. Genomic analyses of recurrent tumors revealed multiple lesions, including spontaneous focal amplification of c-Met or c-Myc. While amplification of c-Met allowed tumor survival dependent on activation of endogenous PI3K, tumors with amplification of c-Myc become independent of the PI3K pathway. Functional analyses further demonstrated that c-Myc contributed to tumors’ independence of oncogene and resistance to PI3K inhibition. Together, our data suggest that MYC elevation in tumors may be a potential mechanism conferring resistance to current PI3K-targeted therapies.

2011-08-02 | GSE27691 | GEO

Mutant PI3K cooperates with HER2 to promote mammary tumor formation and induces trastuzumab resistance in vivo

Project description:HER2 (ERBB2) gene amplification and PIK3CA mutations often co-occur in breast cancer, and aberrant activation of the PI3K pathway has been implicated in resistance to HER2-directed therapies. We have created a mouse model of HER2-overexpressing (HER2+), PIK3CAH1047R-mutant breast cancer. Mice expressing both human HER2 and mutant PIK3CA in their mammary glands developed tumors with a significantly shorter latency compared to mice expressing either oncogene alone. By microarray analysis, HER2-driven tumors clustered with the luminal subtype, whereas HER2+PIK3CA and PIK3CA-driven tumors were associated with the claudin-low breast cancer subtype. In accordance, PIK3CA and HER2+PIK3CA tumors expressed elevated levels of EMT and stem cell markers, and cells from HER2+PIK3CA tumors more efficiently formed mammospheres, providing further evidence that activated PIK3CA may enrich for cancer stem cells. Finally, HER2+PIK3CA tumors are resistant to the HER2 antibody trastuzumab; resistance is partially reversed by the addition of a PI3K inhibitor. Taken together, these studies suggest that the co-expression of HER2 and PI3KH1047R in the mouse mammary gland accelerates the formation of aggressive, trastuzumab-resistant tumors. referenceXsample

2013-09-03 | E-GEOD-41118 | biostudies-arrayexpress

Mutant PI3K cooperates with HER2 to promote mammary tumor formation and induces trastuzumab resistance in vivo

2013-09-03 | GSE41118 | GEO

Gene expression profiling of preneoplastic Lgr5-creERT2/PIK3CAH1047R mammary subsets

Project description:This study examined the effect of mutant PIK3CAH1047R expression in mammary subsets of preneoplastic mammary glands from Lgr5-creERT2/PIK3CA H1047R mice Mammary cell subpopulations were isolated from Lgr5-creERT2/PIK3CA H1047R and Lgr5-creERT2 control animals 4 weeks after activation of PIK3CA H1047R transgene expression by Tamoxifen injection. Pooled mammary glands of 2-3 estrus-synchronized mice per genotype were sorted in 3 independent sortings and used for microarray analysis (24 samples in total).

2015-08-12 | E-GEOD-59870 | biostudies-arrayexpress

MYC is a clinically significant determinant of mTOR inhibitor resistance in breast cancer

Project description:Targeting the PI3K-AKT-mTOR pathway is a promising therapeutic strategy for breast cancer treatment. However, low response rates and the development of acquired resistance to PI3K-AKT-mTOR inhibitors remain major challenges for successful patient treatment. Here, we show that MYC activation is a central and clinically relevant mechanism of resistance to mTOR inhibitors (mTORi) in breast cancer. Multi-omic profiling of mouse invasive lobular carcinoma (ILC) tumors revealed recurrent focal Myc amplification in tumors that acquire resistance to the mTORi AZD8055. The gained MYC activity was significantly associated with biological processes linked to mTORi response. Specifically, MYC counteracted the translation inhibitory effect induced by mTORi by promoting the translation of ribosomal proteins. In vitro and in vivo induction of MYC conferred resistance to AZD8055 as well as the clinically approved mTORi everolimus, both in mouse models of ILC and human breast cancer models. Conversely, AZD8055-resistant ILC cells depended on MYC, as demonstrated by synergistic growth inhibition using mTORi and MYCi combination treatment. Notably, MYC status was significantly associated with poor response to everolimus therapy in metastatic breast cancer patients. Thus, MYC is a clinically relevant determinant of mTORi resistance that may guide the selection of breast cancer patients for mTOR targeted therapies.

2023-05-02 | PXD041927 | Pride

Endogenous expression of an oncogenic PI3K mutation leads to activated PI3K pathway signaling and an invasive phenotype

Project description:The PTEN/PI3K pathway is commonly mutated in cancer and therefore represents a rational target for therapeutic intervention. In order to investigate the primary phenotype(s) mediated by mutant PIK3CA in a clean and highly patient-relevant context, we utilized a non-tumorigenic MCF10A parental and isogenic knock-in cell line that harbors a common activating PIK3CA kinase domain mutation (H1047R). We found that introduction of an endogenously mutated PIK3CA primarily results in a marked epithelial-mesenchymal transition (EMT) and invasive phenotype compared to isogenic wild-type cells. Moreover, a potent and selective inhibitor of PIK3CA (GDC-0941) was highly effective and selective on reversing this phenotype compared to cell-proliferation, highlighting a potential new paradigm for studying PI3K-pathway targeted agents. Keywords: Expression Array Gene expression profiles from a parental MCF10A breast line and an MCF10A clone that has a PI3K activating mutation (H1047R) knocked-in. We plated the cells in 10cm dishes overnight in media with serum, but lacking EGF or insulin. DMSO or GDC-0941 (PI3K inhibitor) at an EC50 concentration were added to triplicate plates of cells in the morning. After 4 hours the RNA was harvested using the Qiagen RNeasy kit. There are 12 samples total.

2011-08-09 | E-GEOD-17785 | biostudies-arrayexpress

Gene expression profiling of preneoplastic K8-creERT2/PIK3CAH1047R mammary subsets

Project description:This study examined the effect of mutant PIK3CAH1047R expression in mammary subsets of preneoplastic mammary glands from K8-creERT2/PIK3CA H1047R mice Mammary cell subpopulations were isolated from K8-creERT2/PIK3CAH1047R and K8-creERT2 control animals 4 weeks after activation of PIK3CA H1047R transgene expression by Tamoxifen injection. Pooled mammary glands of 2-3 estrus-synchronized mice per genotype were sorted in 3 independent sortings and used for microarray analysis (20 samples in total).

2015-08-12 | E-GEOD-65411 | biostudies-arrayexpress

High-dose oncogenic PIK3CA drives constitutive cellular stemness through increased NODAL/TGFb signaling

Project description:Oncogenic PIK3CA mutations activate phosphoinositide 3-kinase (PI3K) and are among the commonest somatic mutations in cancer and mosaic, developmental overgrowth disorders. We recently demonstrated that the ‘hotspot’ variant PIK3CAH1047R exerts striking allele dose-dependent effects on stemness in human induced pluripotent stem cells (iPSCs), and moreover demonstrated multiple oncogenic PIK3CA copies in a substantial subset of human cancers. To identify the molecular mechanism underpinning PIK3CAH1047R allele dose-dependent stemness, we profiled isogenic wild-type, PIK3CAWT/H1047R and PIK3CAH1047R/H1047R iPSCs by high-depth transcriptomics, proteomics and reverse-phase protein arrays (RPPA). PIK3CAH1047R/H1047R iPSCs exhibited altered expression of 5644 genes and 248 proteins, whereas heterozygous hPSCs showed 492 and 54 differentially-expressed genes and proteins, respectively, confirming a nearly deterministic phenotypic effect of homozygosity for PIK3CAH1047R. Pathway and network-based analyses predicted a strong association between self-sustained TGFb/NODAL signaling and the ‘locked’ stemness phenotype induced by homozygosity for PIK3CAH1047R. This stemness gene signature was maintained without exogenous NODAL in PIK3CAH1047R/H1047R iPSCs and was reversed by pharmacological inhibition of TGFb/NODAL signaling but not by PIK3CA-specific inhibition. Analysis of PIK3CA-associated human breast cancers revealed increased expression of the stemness markers NODAL and POU5F1 as a function of disease stage and PIK3CAH1047R allele dosage. Together with emerging realization of the link between NODAL re-expression and aggressive cancer behavior, our data suggest that TGFb/NODAL inhibitors warrant testing in advanced breast tumors with multiple oncogenic PIK3CA copies.

2021-03-03 | PXD014719 | Pride

Elevated expression of wildtype RhoC promotes ErbB2- and Pik3ca-induced mammary tumor formation

Project description:Copy number gains in genes coding for Rho activating exchange factors as well as losses affecting genes coding for RhoGAP proteins are common in breast cancer, suggesting that elevated Rho signaling may play an important role. Extra copies and overexpression of RhoC also occur, although a role for RhoC overexpression in driving tumor formation has not been assessed in vivo. To this end, we report on the development of a Rosa26 (R26)-targeted Cre-conditional RhoC overexpression mouse (R26-RhoC). This mouse was crossed to two models for ERBB2/NEU+ breast cancer: one based on expression of an oncogenic ErbB2/Neu cDNA downstream of the endogenous ErbB2 promoter (FloxNeoNeuNT), the other, a metastatic model that is based on high-level expression from MMTV regulatory elements (NIC). RhoC overexpression dramatically enhanced mammary tumor formation in FloxNeoNeuNT mice but showed a more subtle effect in the NIC line, which forms multiple mammary tumors after a very short latency. Many mammary tumors that form in FloxNeoNeuNT mice show selection for increased NeuNT expression linked to high-level amplification of the ErbB2/NeuNT locus. In contrast, NeuNT overexpression did not require high-level amplification of ErbB2/NeuNT in RhoC-FloxNeoNeuNT lesions. RhoC overexpression also enhanced mammary tumor formation in a model for breast cancer induced by Pik3ca(H1047R). The transforming effect of RhoC was associated with epithelial/mesenchymal transition (EMT) in ErbB2/NeuNT and Pik3ca-H1047R systems. Thus, RhoC copy number gains with resultant overexpression contribute to breast tumor formation and/or progression.

2024-04-11 | GSE249601 | GEO

Development of gene expression signatures for MCF10A cell lines carrying HER2 and WT or H1047R PIK3CA oncogenes.

Project description:We wanted to know how introduction of H1047R oncogenic mutation of PIK3CA (p110a subunit of PI3K) in HER2-overexpressing MCF10A human non-transformed mammary epitheial cell lines introduces change in gene expression levels. Our control was HER2-overexpressing MCF10A cell line with wild-type (WT) PIK3CA. Mutated oncogene-induced gene expression signature was measured and compared with that induced by the WT oncogene from cell lines harvested at 70-80% confluency.

2021-03-16 | GSE117389 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data