Ontology highlight
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PROVIDER: PRJNA256957 | ENA |
REPOSITORIES: ENA
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Project description:Breast cancer is the most frequent cancer in women and consists of heterogeneous types of tumours that are classified into different histological and molecular subtypes1-3. Pik3ca and p53 are the two most frequently mutated genes and are associated with different types of human breast cancers4. The cellular origin and the mechanisms leading to Pik3ca-induced tumour heterogeneity remain unknown. Here, we used a genetic approach in mice to define the cellular origin of Pik3ca-derived tumours and its impact on tumour heterogeneity. Surprisingly, oncogenic Pik3ca-H1047R expression at physiological levels5 in basal cells (BCs) using K5CREERT2 induced the formation of luminal ER+PR+ tumours, while its expression in luminal cells (LCs) using K8CREERT2 gave rise to luminal ER+PR+ tumours or basal-like ER-PR- tumours. Concomitant deletion of p53 and expression of Pik3ca-H1047R accelerated tumour development and induced more aggressive mammary tumours. Interestingly, expression of Pik3ca-H1047R in unipotent BCs gave rise to luminal-like cells, while its expression in unipotent LCs gave rise to basal-like cells before progressing into invasive tumours. Transcriptional profiling of cells that have undergone cell fate transition upon Pik3ca-H1047R expression in unipotent progenitors demonstrate a profound oncogene-induced reprogramming of these newly formed cells and identified gene signatures, characteristic of the different cell fate switches that occur upon Pik3ca-H1047R expression in BC and LCs, which correlated with the cell of origin, tumour type and different clinical outcomes. Altogether our study identifies the cellular origin of Pik3ca-induced tumours and reveals that oncogenic Pik3ca-H1047R activates a multipotent genetic program in normally lineage-restricted populations at the early stage of tumour initiation, setting the stage for future intratumoural heterogeneity. These results have important implications for our understanding of the mechanisms controlling tumour heterogeneity and the development of new strategies to block PIK3CA breast cancer initiation. Luminal and basal cells, or tumour cells, from mice in which expression of PIK3CA-H1047R and YFP (and in some conditions loss of p53) was targeted in basal cells using K5CREERT2 or in luminal cells using K8CREERT2 were FACS isolated and RNA was extracted before being hybridized Affymetrix microarrays.
2015-08-13 | E-GEOD-69290 | biostudies-arrayexpress
Project description:Gene expression profiling of Lgr5-creERT2/PIK3CA H1047R and K8-creERT2/PIK3CA H1047R-evoked mammary tumors
| PRJNA256962 | ENA
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
Project description:Breast cancer is the most frequent cancer in women and consists of heterogeneous types of tumours that are classified into different histological and molecular subtypes1-3. Pik3ca and p53 are the two most frequently mutated genes and are associated with different types of human breast cancers4. The cellular origin and the mechanisms leading to Pik3ca-induced tumour heterogeneity remain unknown. Here, we used a genetic approach in mice to define the cellular origin of Pik3ca-derived tumours and its impact on tumour heterogeneity. Surprisingly, oncogenic Pik3ca-H1047R expression at physiological levels5 in basal cells (BCs) using K5CREERT2 induced the formation of luminal ER+PR+ tumours, while its expression in luminal cells (LCs) using K8CREERT2 gave rise to luminal ER+PR+ tumours or basal-like ER-PR- tumours. Concomitant deletion of p53 and expression of Pik3ca-H1047R accelerated tumour development and induced more aggressive mammary tumours. Interestingly, expression of Pik3ca-H1047R in unipotent BCs gave rise to luminal-like cells, while its expression in unipotent LCs gave rise to basal-like cells before progressing into invasive tumours. Transcriptional profiling of cells that have undergone cell fate transition upon Pik3ca-H1047R expression in unipotent progenitors demonstrate a profound oncogene-induced reprogramming of these newly formed cells and identified gene signatures, characteristic of the different cell fate switches that occur upon Pik3ca-H1047R expression in BC and LCs, which correlated with the cell of origin, tumour type and different clinical outcomes. Altogether our study identifies the cellular origin of Pik3ca-induced tumours and reveals that oncogenic Pik3ca-H1047R activates a multipotent genetic program in normally lineage-restricted populations at the early stage of tumour initiation, setting the stage for future intratumoural heterogeneity. These results have important implications for our understanding of the mechanisms controlling tumour heterogeneity and the development of new strategies to block PIK3CA breast cancer initiation.
2015-08-13 | GSE69290 | GEO
Project description:MCF10A cells: control vs. PIK3CA mutant (H1047R) Transcriptional profiling of MCF10A comparing control (expressing JP1520-PIK3CA-WT; Addgen plasmid #14570) and PIK3CA mutant (JP1520-PIK3CA-H1047R; Addgene plasmic#14572). Goal was to determine the effects of the PIK3CA H1047R mutation in the on global gene expression in MCF10A cells.
2017-02-28 | GSE93422 | GEO
Project description:We have compared the proteome, transcriptome and metabolome of two isogenic cell lines: MCF-10A, derived from human breast epithelium, and the mutant MCF-10A-H1047R. These cell lines differ by a single amino acid substitution (H1047R) caused by single nucleotide change in one allele of the PIK3CA gene which encodes the catalytic subunit p110α of phosphatidylinositol 3-kinase (PI3K). The H1047R mutation of PIK3CA is one of the most frequently encountered somatic cancer-specific mutations. In MCF-10A, this mutation induces an extensive cellular reorganization that far exceeds the known signaling activities of PI3K. The changes are highly diverse; with examples in structural protein levels, the DNA repair machinery and sterol synthesis. Gene set enrichment analysis reveals a highly significant concordance of the genes differentially expressed in MCF-10A-H1047R cells and the established protein and RNA signatures of basal breast cancer. No such concordance was found with the specific gene signatures of other histological types of breast cancer. Our data document the power of a single base mutation, inducing an extensive remodeling of the cell toward the phenotype of a specific cancer. 2 cell lines (H1047R and WT), 4 time points (0, 6, 12, 24 hours), 3 replicates
2015-01-19 | E-GEOD-63452 | biostudies-arrayexpress
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
Project description:Gene expression microarray analyses of PIK3CA H1047R and E545K induced preneoplastic lesions and tumors compared to age matched controls. Plasmids expressing oncogenic forms of PIK3CA (H1047R or E545K mutants) were delivered to the mouse liver by tail vein hydrodynamic injection combined with Sleeping Beauty–mediated somatic integration (SBT-HTVI). Resulting preneoplastic and neoplastic lesions were subjected to gene expression microarray analysis. The putative PIK3CA target gene Galectin1 (Gal1) was further characterized by in vitro studies. Transfection of either PIK3CA E545K or H1047R mutants via SBT-HTVI was sufficient to induce hepatocellular carcinomas in mice. A stepwise hepatocarcinogenesis from singular pericentral lipid-rich preneoplastic hepatocytes to clusters, expansive preneoplastic lesions, and HCCs was observed. In PIK3CA H1047R injected mice, HCCs were detected in the 12 months injection group, while PIK3CA E545K injections resulted in tumor occurrence as early as 3 months after SB-HTVI. Histologically, a predominant lipid-rich phenotype characterized all tumorigenesis stages, as confirmed by Sudan III staining and electron microscopy. Immunohistochemically, preneoplastic lesions and tumors displayed high levels of the lipid master regulators Fatty acid synthase and Stearoyl-CoA desaturase-1. Gal1 was commonly overexpressed in PIK3CA-driven preneoplastic and neoplastic liver lesions by gene expression microarray analysis compared with age-matched controls.
2021-05-06 | GSE173963 | GEO
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
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