Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA96337 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Dysregulation of the PI3K/AKT pathway is a common occurrence in ovarian carcinomas. Loss of the tumour suppressor PTEN in high-grade serous ovarian carcinoma (HGSOC) is associated with a patient subgroup with poor prognosis. The cellular mechanisms of how PTEN loss contributes to HGSOC are largely unknown. We utilise long-term time-lapse imaging of HGSOC spheroids coupled to a machine learning approach to classify the phenotype of PTEN loss. PTEN deficiency does not affect proliferation but rather induces PI(3,4,5)P3-rich and -dependent membrane protrusions into the extracellular matrix (ECM), resulting in a collective invasion phenotype. We identify the small GTPase ARF6 as a crucial vulnerability upon PTEN loss. Through a functional proteomic CRISPR screen of ARF6 interactors, we identify the ARF GTPase-activating protein (GAP) AGAP1 and the ECM receptor β1-integrin as key ARF6 interactors regulating the PTEN loss-associated invasion phenotype. ARF6 functions to promote invasion by controlling the recycling of internalised, active β1-integrin complexes to maintain invasive activity into the ECM. The expression of the ARF6-centred complex in HGSOC patients is inversely associated with outcome, allowing identification of patient groups with improved versus poor outcome. ARF6 may represent a new therapeutic vulnerability in PTEN-depleted HGSOC tumours.
2023-07-11 | PXD038305 | Pride
Project description:Pathway-specific therapy is the future of cancer management. The oncogenic phosphatidylinositol 3-kinase (PI3K) pathway is frequently activated in solid tumors; however, currently, no reliable test for PI3K pathway activation exists for human tumors. Taking advantage of the observation that loss of PTEN, the negative regulator of PI3K, results in robust activation of this pathway, we developed and validated a microarray gene expression signature for immunohistochemistry (IHC)-detectable PTEN loss in breast cancer (BC). The most significant signature gene was PTEN itself, indicating that PTEN mRNA levels are the primary determinant of PTEN protein levels in BC. Some PTEN IHC-positive BCs exhibited the signature of PTEN loss, which was associated to moderately reduced PTEN mRNA levels cooperating with specific types of PIK3CA mutations and/or amplification of HER2. This demonstrates that the signature is more sensitive than PTEN IHC for identifying tumors with pathway activation. In independent data sets of breast, prostate, and bladder carcinoma, prediction of pathway activity by the signature correlated significantly to poor patient outcome. Stathmin, encoded by the signature gene STMN1, was an accurate IHC marker of the signature and had prognostic significance in BC. Stathmin was also pathway-pharmacodynamic in vitro and in vivo. Thus, the signature or its components such as stathmin may be clinically useful tests for stratification of patients for anti-PI3K pathway therapy and monitoring therapeutic efficacy. This study indicates that aberrant PI3K pathway signaling is strongly associated with metastasis and poor survival across carcinoma types, highlighting the enormous potential impact on patient survival that pathway inhibition could achieve. Keywords: Disease state analysis
2007-04-07 | GSE5325 | GEO
Project description:Phosphates and tensin homolog (PTEN) is a critical tumor suppressor, and even partial reduction of PTEN levels increases cancer susceptibility. PTEN loss frequently occurs in non-small cell lung carcinoma (NSCLC) and is associated with poor diagnosis. However, there are no effective interventions available to prevent or restore PTEN loss. CREB binding protein (CREBBP or CBP) is a well-known acetyltransferase. PTEN loss in lung cancer carrying CBP loss-of-function (LOF) mutations has not been addressed. Here, we showed that the decreased acetylation of histone deacetylase 3 (HDAC3) due to CBP LOF mutations contributes to PTEN loss in lung cancer. HDAC3 is a member of the class I histone deacetylase family. We found HDAC3 itself is acetylated by CBP at a previously unknown acetylation residue. Our data demonstrated that HDAC3 acetylation is required for gearing down HDAC3 activity and increasing the acetylation of histone proteins to promote the transcription of PTEN. Our findings suggest that HDAC3 acetylation is required for preserving the PTEN expression. The impaired HDAC3 acetylation in CBP LOF mutation lung cancer leads to PTEN loss and consequently promotes tumorigenesis and tumor resistance to chemotherapy. Our findings reveal epigenetic mechanisms of regulating PTEN expression and indicate HDAC3 is a potential target for restoring the tumor suppressor PTEN in CBP LOF mutation cancer.
2024-12-31 | PXD026628 | JPOST Repository
Project description:PTEN, a widely investigated tumor suppressor, has at least two longer translational variants, PTEN and . However, the regulation and precise roles of endogenous PTEN/ in tumorigenesis remain greatly unknown. Here we show that USP9X and FBXW11 selectively regulate the stability of PTEN/ but not PTEN proteins by deubiqitination and ubiquitination respectively. USP9X promotes and FBXW11 suppresses tumorigenesis mediated by PTEN/. In contrast to the current paradigm for PTEN as a tumor suppressor, PTEN/ promote tumorigenesis of cancer cells in a phosphatase-independent manner. Mechanistically, PTEN/ localized in the nucleus regulate expressions of tumor-promoting genes such as NOTCH3 in the similar way as the H3K4 presenter WDR5. Further, PTEN/ but not PTEN directly interact with WDR5 to promote trimethylation of H3K4 and maintain a tumor-promoting signature. Taken together, our results indicate that PTEN/ are a double-edged sword for carcinogenesis, suggesting that reinterpretation of the importance of PTEN gene in carcinogenesis is warranted.
2019-11-14 | PXD013196 | Pride
Project description:Activation of the PI3K pathway in estrogen receptor α (ER)-positive (+) breast cancer is associated with reduced ER expression and activity, luminal B subtype, and poor outcome. PTEN is a negative regulator of the PI3K pathway typically lost in ER-negative (-) breast cancer. To clarify the effect of PTEN down-regulation on the response of ER+/HER2- breast cancer to endocrine therapy, we established reduced PTEN cell models using inducible knockdown. We found that only moderate PTEN reduction is sufficient to enhance PI3K signaling, generate a gene signature associated with luminal B subtype, and cause endocrine resistance. Combining endocrine therapy with mTOR, AKT, or MEK inhibitors improves antitumor activity, but the efficacy varies by type of endocrine therapy and the specific inhibitor. Fulvestrant plus an AKT inhibitor is the most potent combination when PTEN is reduced, inducing apoptosis and tumor regression. This combination deserves further study in patients with PI3K pathway activation.
2014-06-30 | GSE53300 | GEO
Project description:The PTEN tumor suppressor controls cell death and survival by regulating functions of various molecular targets. Whilst the role of PTEN lipid-phosphatase activity on PtdIns(3,4,5)P3 and inhibition of PI3K pathway is well characterized, the biological relevance of PTEN protein-phosphatase activity remains undefined. Using knock-in (KI) mice harbouring cancer-associated and functionally relevant missense mutations, we show that although loss of PTEN lipid-phosphatase function cooperates with oncogenic PI3K to promote rapid mammary tumorigenesis, the additional loss of PTEN protein-phosphatase activity triggered an extensive cell death response evident in early and advanced mammary tumors. Omics and drug-targeting studies revealed that PI3Ks act to reduce glucocorticoid receptor (GR) levels, which are rescued by loss of PTEN protein-phosphatase activity to restrain cell survival. The dual regulation of GR by PI3K and PTEN functions as a rheostat that can be exploited for the treatment of PTEN-loss driven cancers.
2020-10-15 | PXD016184 | Pride
Project description:The retinoblastoma tumor suppressor (RB1) plays a critical role in coordinating multiple pathways that impact on tumor initiation, disease progression, and therapeutic responses. Here we interrogated the TCGA pan-cancer data collection to probe fundamental molecular features associated with the RB-pathway across 31 tumor-types. While the RB-pathway has been purported to exhibit multiple mutually exclusive events, only RB1 is mutually exclusive with multiple genetic events that deregulate CDK4/6 activity. Using an isogenic ER+ breast cancer model with targeted RB1 deletion, we identified gene expression features that link CDK4/6 activity and RB-dependency (CDK4/6-RB integrated signature). This gene expression signature is associated with prognosis across a spectrum of tumors that exhibit average lower signature value indicative of more indolent diseases. Single copy loss on chromosome 13q encompassing the RB1 locus is prevalent in many cancers, and is associated with reduced expression of multiple genes on 13q including RB1, and inversely related to the CDK4/6-RB integrated signature supporting a genetic cause/effect relationship. To probe the broader implications on tumor biology, we investigated genes that are positively and inversely correlated with the CDK4/6-RB integrated signature. This approach defined tumor-specific pathways that could represent new therapeutic vulnerabilities associated with RB-pathway activity.
2020-03-02 | GSE145316 | GEO
Project description:The tumor suppressor PTEN is frequently inactivated in breast and other cancers; yet, germ-line mutations in this gene induce non-malignant hamartomas, indicating dependency on additional cooperating events. Here we show that most tumors derived from conditional deletion of mouse Pten in mammary epithelium are highly differentiated and lack transplantable tumor initiating cells (TICs) capable of seeding new tumors following orthotopic injection of FACS-sorted or tumorsphere cells. A rare group of poorly differentiated tumors did harbour transplantable TICs. These transplantable tumors exhibited distinct molecular classification, signaling pathways, chromosomal aberrations and mutational landscape, as well as reduced expression of microRNA-143/145. Stable knockdown of miR-143/145 conferred tumorigenic potential upon poorly transplantable Pten-deficient tumor cells through a mechanism involving induction of RAS signaling, leading to increased sensitivity to MEK inhibition. In humans, miR145-deficiency significantly correlated with elevated RAS pathway activity in basal-like breast cancer, and patients with combined PTEN/miR-145 loss or PTEN-loss/RAS pathway activation exhibited poor clinical outcome. These results underscore a selective pressure for combined PTEN loss together with miR-145 loss or high RAS-pathway activity in aggressive forms of breast cancer, and a need to identify and prioritize these tumors for aggressive therapy. Array CGH data comparing 2 types of Pten-deficient tumors (well and poorly differentiated) with other modles of mouse mammary tumors
2017-08-18 | GSE99495 | GEO
Project description:The tumor suppressor PTEN is frequently inactivated in breast and other cancers; yet, germ-line mutations in this gene induce non-malignant hamartomas, indicating dependency on additional cooperating events. Here we show that most tumors derived from conditional deletion of mouse Pten in mammary epithelium are highly differentiated and lack transplantable tumor initiating cells (TICs) capable of seeding new tumors following orthotopic injection of FACS-sorted or tumorsphere cells. A rare group of poorly differentiated tumors did harbour transplantable TICs. These transplantable tumors exhibited distinct molecular classification, signaling pathways, chromosomal aberrations and mutational landscape, as well as reduced expression of microRNA-143/145. Stable knockdown of miR-143/145 conferred tumorigenic potential upon poorly transplantable Pten-deficient tumor cells through a mechanism involving induction of RAS signaling, leading to increased sensitivity to MEK inhibition. In humans, miR145-deficiency significantly correlated with elevated RAS pathway activity in basal-like breast cancer, and patients with combined PTEN/miR-145 loss or PTEN-loss/RAS pathway activation exhibited poor clinical outcome. These results underscore a selective pressure for combined PTEN loss together with miR-145 loss or high RAS-pathway activity in aggressive forms of breast cancer, and a need to identify and prioritize these tumors for aggressive therapy. Expression data comparing 2 types of Pten-deficient tumors (spindle and poorly differentiated) with other models of mouse mammary tumors
2017-06-02 | GSE99493 | GEO
Project description:Phosphatase and tensin homologue (PTEN) is the most frequently mutated tumor suppressor gene in human prostate cancer. Synthetic essentiality is defined as cancer that harbors a specific tumor suppressor deficiency is dependent on synthetic-essential genes for the malignant phenotypes. Recently, targeting such synthetic-essential genes has become an attractive treatment approach for cancers that acquire loss-of-function mutations in tumor suppressor genes. Here, we show that AT-rich interaction domain 4B (ARID4B) functions as a synthetic-essential gene in prostate tumorigenesis driven by PTEN deficiency. This functional interaction between ARID4B and PTEN is recapitulated in the mouse model carrying prostate-specific deletions of Pten and Arid4b in which ablation of ARID4B attenuated prostate cancer progression elicited by loss of PTEN. Although the tumor suppressor function of PTEN is most attributed to its lipid phosphatase activity that counters the PI3K action in cytoplasm, we identified the PTEN-ARID4B-PI3K axis in which nuclear PTEN inhibits expression of ARID4B, while ARID4B serves as a transcriptional activator of the PI3K subunits PIK3CA and PIK3R2 to trigger the PI3K/AKT pathway. Our study further demonstrated that the reciprocal binding of ARID4B and histone H1 to the PIK3CA and PIK3R2 promoters modulates chromatin condensation, indicating a mechanism by which ARID4B activates these promoters. Finally, a three-gene signature consisting of PTEN, ARID4B, and PI3K substantially improves the predictive power for tumor recurrence in human prostate cancer patients, underscoring the clinical significance of this newly identified PTEN-ARID4B-PI3K axis. These findings reveal a novel synthetic-essential relationship between ARID4B and PTEN, thus exposing a previously unidentified cancer-specific vulnerability, and supporting ARID4B as a potential therapeutic target for prostate cancer patients with PTEN mutations.
2019-08-23 | GSE116669 | GEO