Activating AKT1 and PIK3CA mutations in metastatic castration-resistant prostate cancer
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ABSTRACT:
PROVIDER: EGAS00001004328 | EGA |
REPOSITORIES: EGA
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Project description:The human oncogene PIK3CA is frequently mutated in human cancers. The two hotspot mutations in PIK3CA, E545K and H1047R, have been shown to regulate widespread signaling events downstream of AKT. However, the impact of these activating mutations on the tyrosine phosphorylation signaling in the cell has not been studied. Here, we performed a global phosphotyrosine profiling using isogenic knockin cell lines containing these activating mutations. We identified 824 unique phosphopeptides from 308 proteins. We found a surprisingly widespread modulation of tyrosine phosphorylation levels of proteins in the knockin mutant cells, with many of the regulated proteins involved in important biological processes, including those in the cytoskeletal migration pathways and kinase regulated signaling. We observed a widespread modulation of the tyrosine kinome, with 24 of the tyrosine kinases showing either upregulation or downregulation in phosphorylation levels. Many of the regulated phosphosites that we identified were located in the kinase domain or the canonical activating sites, indicating that the kinases were active and hence their downstream signaling pathways. Our study thus shows that the activating mutations in PIK3CA result in widespread tyrosine signaling regulation, in addition to the serine/threonine signaling pathways activated by the canonical PI3K-AKT axis.
2018-10-24 | PXD001460 | Pride
Project description:The widespread and long-term use of potent therapies designed to repress androgen receptor (AR) signaling is changing the molecular and phenotypic landscapes of prostate cancer. We conducted molecular profiling of metastatic castration-resistant prostate cancer (mCRPC) patient specimens and patient-derived xenograft models and identified five distinct mCRPC phenotypes. Herein, we characterize an AR-low phenotype that has low AR expression with concomitant decreases in a subset of AR regulated genes, and an amphicrine phenotype that has both AR and neuroendocrine activity in the same cell. Furthermore, our data highlight an emerging squamous cell mCRPC phenotype.
2019-07-17 | GSE126078 | GEO
Project description:PI3K (phosphoinositide 3-kinase)/AKT and RAS/MAPK (mitogen-activated protein kinase) pathway coactivation in the prostate epithelium promotes both epithelial–mesenchymal transition (EMT) and metastatic castration-resistant prostate cancer (mCRPC), which is currently incurable. To study the dynamic regulation of the EMT process, we developed novel genetically defined cellular and in vivo model systems from which epithelial, EMT and mesenchymal-like tumor cells with Pten deletion and Kras activation can be isolated. When cultured individually, each population has the capacity to regenerate all three tumor cell populations, indicative of epithelial–mesenchymal plasticity. Despite harboring the same genetic alterations, mesenchymal-like tumor cells are resistant to PI3K and MAPK pathway inhibitors, suggesting that epigenetic mechanisms may regulate the EMT process, as well as dictate the heterogeneous responses of cancer cells to therapy. Among differentially expressed epigenetic regulators, the chromatin remodeling protein HMGA2 is significantly upregulated in EMT and mesenchymal-like tumors cells, as well as in human mCRPC. Knockdown of HMGA2, or suppressing HMGA2 expression with the histone deacetylase inhibitor LBH589, inhibits epithelial–mesenchymal plasticity and stemness activities in vitro and markedly reduces tumor growth and metastasis in vivo through successful targeting of EMT and mesenchymal-like tumor cells. Importantly, LBH589 treatment in combination with castration prevents mCRPC development and significantly prolongs survival following castration by enhancing p53 and androgen receptor acetylation and in turn sensitizing castration-resistant mesenchymal-like tumor cells to androgen deprivation therapy. Taken together, these findings demonstrate that cellular plasticity is regulated epigenetically, and that mesenchymal-like tumor cell populations in mCRPC that are resistant to conventional and targeted therapies can be effectively treated with the epigenetic inhibitor LBH589.
2015-10-12 | GSE67872 | GEO
Project description:PI3K (phosphoinositide 3-kinase)/AKT and RAS/MAPK (mitogen-activated protein kinase) pathway coactivation in the prostate epithelium promotes both epithelial–mesenchymal transition (EMT) and metastatic castration-resistant prostate cancer (mCRPC), which is currently incurable. To study the dynamic regulation of the EMT process, we developed novel genetically defined cellular and in vivo model systems from which epithelial, EMT and mesenchymal-like tumor cells with Pten deletion and Kras activation can be isolated. When cultured individually, each population has the capacity to regenerate all three tumor cell populations, indicative of epithelial–mesenchymal plasticity. Despite harboring the same genetic alterations, mesenchymal-like tumor cells are resistant to PI3K and MAPK pathway inhibitors, suggesting that epigenetic mechanisms may regulate the EMT process, as well as dictate the heterogeneous responses of cancer cells to therapy. Among differentially expressed epigenetic regulators, the chromatin remodeling protein HMGA2 is significantly upregulated in EMT and mesenchymal-like tumors cells, as well as in human mCRPC. Knockdown of HMGA2, or suppressing HMGA2 expression with the histone deacetylase inhibitor LBH589, inhibits epithelial–mesenchymal plasticity and stemness activities in vitro and markedly reduces tumor growth and metastasis in vivo through successful targeting of EMT and mesenchymal-like tumor cells. Importantly, LBH589 treatment in combination with castration prevents mCRPC development and significantly prolongs survival following castration by enhancing p53 and androgen receptor acetylation and in turn sensitizing castration-resistant mesenchymal-like tumor cells to androgen deprivation therapy. Taken together, these findings demonstrate that cellular plasticity is regulated epigenetically, and that mesenchymal-like tumor cell populations in mCRPC that are resistant to conventional and targeted therapies can be effectively treated with the epigenetic inhibitor LBH589.
2015-10-07 | GSE67681 | GEO
Project description:Background: PIK3CA mutations are observed in >30% of breast cancers, which are more common in estrogen receptor (ERα)-positive breast cancer compared with ERα-negative breast cancer. AKT1, 2, and 3 isoforms, major isoforms downstream of PI3K, modulate ERα activity. It is unknown whether PIK3CA mutation leads to preferential activation of specific AKT isoforms with an ability to modulate ERα function. Methods: Gene expression arrays were performed on parental, AKT1 knockdown or AKT2 knockdown MCF-7 breast cancer cells with or without estradiol treatment for three hours. Results: AKT1 had a dominant role in ERα:estradiol-dependent gene expression and proliferation. We have identified a unique gene expression signature that is dependent on ERα, estradiol, AKT1 and the pioneer factor FOXA1. Overexpression of this signature was associated with better outcome in patients with ERα-positive breast cancer. In contrast, AKT2 controlled global gene expression.
2016-08-10 | GSE60759 | GEO
Project description:Copy number profiling of mCRPC
2020-04-28 | E-MTAB-7326 | biostudies-arrayexpress
Project description:Neuroendocrine (NE) differentiation in metastatic castration-resistant prostate cancer (mCRPC) usually develops through cellular plasticity. We recently characterized two mCRPC phenotypes with NE features; Androgen receptor (AR)-positive, NE-positive amphicrine prostate cancer (AMPC) and AR-negative small cell or neuroendocrine prostate cancer (SCNPC). Here, we interrogate the RE-1 silencing transcription factor (REST) pathway in mCRPC and demonstrate that SRRM3 has analogous functions to SRRM4 and mediates NE differentiation through alternative splicing of REST. We scrutinize transcriptome datasets across species and tumor types and discover that SRRM3 and SRRM4 expression define molecular phenotypes in AMPC and SCNPC. Notably, we characterize two AMPC phenotypes driven by either REST attenuation or ASCL1 activity and three SCNPC phenotypes with progressive activation of neuronal transcription factor programs. Together, our data provides a biological framework for classifying NE phenotypes in mCRPC that could be useful for future therapeutic development and precision medicine applications.
2021-07-14 | GSE158598 | GEO
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:Neuroendocrine (NE) differentiation in metastatic castration-resistant prostate cancer (mCRPC) usually develops through cellular plasticity. We recently characterized two mCRPC phenotypes with NE features; Androgen receptor (AR)-positive, NE-positive amphicrine prostate cancer (AMPC) and AR-negative small cell or neuroendocrine prostate cancer (SCNPC). Here, we interrogate the RE-1 silencing transcription factor (REST) pathway in mCRPC and demonstrate that SRRM3 has analogous functions to SRRM4 and mediates NE differentiation through alternative splicing of REST. We scrutinize transcriptome datasets across species and tumor types and discover that SRRM3 and SRRM4 expression define molecular phenotypes in AMPC and SCNPC. Notably, we characterize two AMPC phenotypes driven by either REST attenuation or ASCL1 activity and three SCNPC phenotypes with progressive activation of neuronal transcription factor programs. Together, our data provides a biological framework for classifying NE phenotypes in mCRPC that could be useful for future therapeutic development and precision medicine applications.
2021-07-14 | GSE158593 | GEO
Project description:<p>Most prostate cancer deaths are caused by metastatic, castration resistant disease (mCRPC). To develop a precision medicine framework for mCRPC, we established a multi-institutional, international clinical sequencing infrastructure to enroll and carry out prospective whole exome and transcriptome sequencing of tumors from a cohort of mCRPC patients. We obtained high quality DNA and RNA sequence data from 150 bone or soft tissue biopsies. Central pathology revealed high-grade adenocarcinoma with only four cases (3.6%) showing neuroendocrine differentiation. Aberrations of AR, ETS genes, TP53 and PTEN were frequent (40-60% of cases), with TP53 and AR alterations being the most enriched in mCRPC compared to primary prostate cancer. We identified novel genomic alterations in PIK3CA/B (fusions and mutations); R-spondin, BRAF and RAF1 (fusions); APC (inactivating mutations); delta-catenin (missense mutations); and ZBTB16/PLZF (homozygous deletions). Aberrations of BRCA2, BRCA1 and ATM were observed at substantially higher frequencies (19.3% overall) than seen in primary prostate cancers, with 56% of these being exclusively somatic. Putative driver gene alterations were identified in nearly all patients, and over half also harbored driver gene fusions, homozygous deletions and/or amplifications. Moreover, 89% of patients harbored a clinically actionable aberration including 62.7% with aberrations in AR, 65% in other cancer-related genes, and 8% with actionable pathogenic germline alterations. Overall, integrative clinical sequencing analysis can be safely and efficiently performed in mCRPC, yields findings that may be actionable for enrolling patients in clinical trials of targeted therapies, and may inform the basis of individual clinical responses.</p>
| phs000915 | dbGaP