Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 569
Filter
1.
Epilepsy Res ; 206: 107440, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39213710

ABSTRACT

Seizures induce hippocampal subregion dependent enhancements in microglia/macrophage phagocytosis and cytokine release that may contribute to the development of epilepsy. As a model of hyperactive mTOR induced epilepsy, neuronal subset specific phosphatase and tensin homolog (NS-Pten) knockout (KO) mice exhibit hyperactive mTOR signaling in the hippocampus, seizures that progress with age, and enhanced hippocampal microglia/macrophage activation. However, it is unknown where microglia/macrophages are most active within the hippocampus of NS-Pten KO mice. We quantified the density of IBA1 positive microglia/macrophages in the CA1, CA2/3, and dentate gyrus of NS-Pten KO and wildtype (WT) male and female mice at 4, 10, and 15 weeks of age. NS-Pten KO mice exhibited an overall increase in the number of IBA1 positive microglia/macrophages in each subregion and in the entire hippocampus. After accounting for differences in size, the whole hippocampus of NS-Pten KO mice still exhibited an increased density of IBA1 positive microglia/macrophages. Subregion analyses showed that this increase was restricted to the dentate gyrus of both male and female NS-Pten KO mice and to the CA1 of male NS-Pten KO mice. These data suggest enhanced microglia/macrophage activity may occur in the NS-Pten KO mice in a hippocampal subregion and sex-dependent manner. Future work should seek to determine whether these region-specific increases in microgliosis play a role in the progression of epilepsy in this model.


Subject(s)
Hippocampus , Macrophages , Microglia , PTEN Phosphohydrolase , Sex Characteristics , Animals , Female , Male , Mice , Calcium-Binding Proteins/metabolism , Cell Count , Hippocampus/metabolism , Macrophages/metabolism , Mice, Inbred C57BL , Mice, Knockout , Microfilament Proteins/metabolism , Microglia/metabolism , PTEN Phosphohydrolase/genetics , PTEN Phosphohydrolase/deficiency , PTEN Phosphohydrolase/metabolism
2.
Cancer Res Commun ; 4(8): 2215-2227, 2024 Aug 01.
Article in English | MEDLINE | ID: mdl-39087397

ABSTRACT

Intrinsic resistance to targeted therapeutics in PTEN-deficient glioblastoma (GBM) is mediated by redundant signaling networks that sustain critical metabolic functions. Here, we demonstrate that coordinated inhibition of the ribosomal protein S6 kinase 1 (S6K1) and the receptor tyrosine kinase AXL using LY-2584702 and BMS-777607 can overcome network redundancy to reduce GBM tumor growth. This combination of S6K1 and AXL inhibition suppressed glucose flux to pyrimidine biosynthesis. Genetic inactivation studies to map the signaling network indicated that both S6K1 and S6K2 transmit growth signals in PTEN-deficient GBM. Kinome-wide ATP binding analysis in inhibitor-treated cells revealed that LY-2584702 directly inhibited S6K1, and substrate phosphorylation studies showed that BMS-777607 inactivation of upstream AXL collaborated to reduce S6K2-mediated signal transduction. Thus, combination targeting of S6K1 and AXL provides a kinase-directed therapeutic approach that circumvents signal transduction redundancy to interrupt metabolic function and reduce growth of PTEN-deficient GBM. SIGNIFICANCE: Therapy for glioblastoma would be advanced by incorporating molecularly targeted kinase-directed agents, similar to standard of care strategies in other tumor types. Here, we identify a kinase targeting approach to inhibit the metabolism and growth of glioblastoma.


Subject(s)
Axl Receptor Tyrosine Kinase , Glioblastoma , PTEN Phosphohydrolase , Proto-Oncogene Proteins , Pyrimidines , Receptor Protein-Tyrosine Kinases , Glioblastoma/drug therapy , Glioblastoma/metabolism , Glioblastoma/pathology , Glioblastoma/genetics , Humans , Receptor Protein-Tyrosine Kinases/metabolism , Receptor Protein-Tyrosine Kinases/genetics , Receptor Protein-Tyrosine Kinases/antagonists & inhibitors , PTEN Phosphohydrolase/metabolism , PTEN Phosphohydrolase/deficiency , PTEN Phosphohydrolase/genetics , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins/antagonists & inhibitors , Proto-Oncogene Proteins/genetics , Pyrimidines/pharmacology , Cell Line, Tumor , Animals , Signal Transduction/drug effects , Mice , Ribosomal Protein S6 Kinases, 70-kDa/metabolism , Ribosomal Protein S6 Kinases, 70-kDa/genetics , Brain Neoplasms/drug therapy , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Brain Neoplasms/genetics , Xenograft Model Antitumor Assays , Protein Kinase Inhibitors/pharmacology , Cell Proliferation/drug effects , Aminopyridines , Pyridones
3.
Nature ; 617(7959): 139-146, 2023 05.
Article in English | MEDLINE | ID: mdl-37076617

ABSTRACT

Loss of the PTEN tumour suppressor is one of the most common oncogenic drivers across all cancer types1. PTEN is the major negative regulator of PI3K signalling. The PI3Kß isoform has been shown to play an important role in PTEN-deficient tumours, but the mechanisms underlying the importance of PI3Kß activity remain elusive. Here, using a syngeneic genetically engineered mouse model of invasive breast cancer driven by ablation of both Pten and Trp53 (which encodes p53), we show that genetic inactivation of PI3Kß led to a robust anti-tumour immune response that abrogated tumour growth in syngeneic immunocompetent mice, but not in immunodeficient mice. Mechanistically, PI3Kß inactivation in the PTEN-null setting led to reduced STAT3 signalling and increased the expression of immune stimulatory molecules, thereby promoting anti-tumour immune responses. Pharmacological PI3Kß inhibition also elicited anti-tumour immunity and synergized with immunotherapy to inhibit tumour growth. Mice with complete responses to the combined treatment displayed immune memory and rejected tumours upon re-challenge. Our findings demonstrate a molecular mechanism linking PTEN loss and STAT3 activation in cancer and suggest that PI3Kß controls immune escape in PTEN-null tumours, providing a rationale for combining PI3Kß inhibitors with immunotherapy for the treatment of PTEN-deficient breast cancer.


Subject(s)
Immune Evasion , Mammary Neoplasms, Animal , PTEN Phosphohydrolase , Phosphatidylinositol 3-Kinase , Animals , Mice , Immunotherapy , Phosphatidylinositol 3-Kinase/metabolism , Phosphoinositide-3 Kinase Inhibitors , PTEN Phosphohydrolase/deficiency , PTEN Phosphohydrolase/genetics , Signal Transduction , Mammary Neoplasms, Animal/enzymology , Mammary Neoplasms, Animal/genetics , Mammary Neoplasms, Animal/immunology , Mammary Neoplasms, Experimental/enzymology , Mammary Neoplasms, Experimental/genetics , Mammary Neoplasms, Experimental/immunology
4.
Front Immunol ; 13: 797244, 2022.
Article in English | MEDLINE | ID: mdl-35185889

ABSTRACT

PTEN (Phosphatase and TENsin homolog) is a well-known tumor suppressor involved in numerous types of cancer, including T-cell acute lymphoblastic leukemia (T-ALL). In human, loss-of-function mutations of PTEN are correlated to mature T-ALL expressing a T-cell receptor (TCR) at their cell surface. In accordance with human T-ALL, inactivation of Pten gene in mouse thymocytes induces TCRαß+ T-ALL development. Herein, we explored the functional interaction between TCRαß signaling and PTEN. First, we performed single-cell RNA sequencing (scRNAseq) of PTEN-deficient and PTEN-proficient thymocytes. Bioinformatic analysis of our scRNAseq data showed that pathological Ptendel thymocytes express, as expected, Myc transcript, whereas inference of pathway activity revealed that these Ptendel thymocytes display a lower calcium pathway activity score compared to their physiological counterparts. We confirmed this result using ex vivo calcium flux assay and showed that upon TCR activation tumor Ptendel blasts were unable to release calcium ions (Ca2+) from the endoplasmic reticulum to the cytosol. In order to understand such phenomena, we constructed a mathematical model centered on the mechanisms controlling the calcium flux, integrating TCR signal strength and PTEN interactions. This qualitative model displays a dynamical behavior coherent with the dynamics reported in the literature, it also predicts that PTEN affects positively IP3 (inositol 1,4,5-trisphosphate) receptors (ITPR). Hence, we analyzed Itpr expression and unraveled that ITPR proteins levels are reduced in PTEN-deficient tumor cells compared to physiological and leukemic PTEN-proficient cells. However, calcium flux and ITPR proteins expression are not defective in non-leukemic PTEN-deficient T cells indicating that beyond PTEN loss an additional alteration is required. Altogether, our study shows that ITPR/Calcium flux is a part of the oncogenic landscape shaped by PTEN loss and pinpoints a putative role of PTEN in the regulation of ITPR proteins in thymocytes, which remains to be characterized.


Subject(s)
Calcium Signaling/genetics , PTEN Phosphohydrolase/deficiency , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/genetics , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/metabolism , Receptors, Antigen, T-Cell, alpha-beta/metabolism , Thymocytes/metabolism , Animals , Cell Proliferation/genetics , Mice , Mice, Transgenic , PTEN Phosphohydrolase/genetics , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/pathology , Thymocytes/pathology
5.
Nat Commun ; 13(1): 83, 2022 01 10.
Article in English | MEDLINE | ID: mdl-35013169

ABSTRACT

Phosphoinositides are a family of membrane lipids essential for many biological and pathological processes. Due to the existence of multiple phosphoinositide regioisomers and their low intracellular concentrations, profiling these lipids and linking a specific acyl variant to a change in biological state have been difficult. To enable the comprehensive analysis of phosphoinositide phosphorylation status and acyl chain identity, we develop PRMC-MS (Phosphoinositide Regioisomer Measurement by Chiral column chromatography and Mass Spectrometry). Using this method, we reveal a severe skewing in acyl chains in phosphoinositides in Pten-deficient prostate cancer tissues, extracellular mobilization of phosphoinositides upon expression of oncogenic PIK3CA, and a unique profile for exosomal phosphoinositides. Thus, our approach allows characterizing the dynamics of phosphoinositide acyl variants in intracellular and extracellular milieus.


Subject(s)
Class I Phosphatidylinositol 3-Kinases/genetics , Metabolome , PTEN Phosphohydrolase/genetics , Phosphatidylinositols/metabolism , Prostatic Neoplasms/metabolism , Animals , Chromatography, Affinity , Class I Phosphatidylinositol 3-Kinases/metabolism , Epidermal Growth Factor/pharmacology , Exosomes/chemistry , Exosomes/metabolism , Gene Expression , HEK293 Cells , HeLa Cells , Humans , Male , Mass Spectrometry , Mice , PC-3 Cells , PTEN Phosphohydrolase/deficiency , Phosphatidylinositols/chemistry , Phosphatidylinositols/classification , Phosphatidylinositols/isolation & purification , Prostate/chemistry , Prostate/drug effects , Prostate/pathology , Prostatic Neoplasms/genetics , Prostatic Neoplasms/pathology , Pyrimidines/pharmacology , Quinazolines/pharmacology , Stereoisomerism
6.
Life Sci ; 293: 120264, 2022 Mar 15.
Article in English | MEDLINE | ID: mdl-35031262

ABSTRACT

AIMS: This study evaluated the association of mucinous metaplasia (MM) with tumor cell proliferation, androgen receptor (AR) expression and invasiveness in Pten conditional knockout mice and the prognostic value of MM markers for patients with PCa. MAIN METHODS: Prostatic lobes samples from genetic engineered mouse model Ptenf/f and Pb-Cre4/Ptenf/f were submitted for histopathological analysis and tissue expression of AR, the proliferation marker Ki67, alpha-smooth muscle actin, and laminin. RNAseq data of prostatic lobes samples were analyzed searching for MM gene expression patterns. We also investigated gene and protein expression related to MM in human PCa public databases. KEY FINDINGS: All knockout animals analyzed showed at least one area of stroma-invading MM, which was absent in the control animals. The tumoral regions of MM showed a proliferative index 5 times higher than other tumoral areas and low expression of the AR (less than 20% of the cells were AR-positive). Disrupted basement membrane areas were observed in MM. The mouse and human PCa transcriptomes exhibited increased expression of the MM markers such as MUC1, MUC19, MUC4, MUC5AC, MUC5B, and TFF3. Gene expression profile was associated with castration-resistant prostate cancer (CRPC) and with a lower probability of freedom from biochemical recurrence. SIGNIFICANCE: The expression of goblet cell genes, such as MUC1, MUC5AC, MUC5B, and TFF3 have significant prognostic value for PCa patients and represent another class of potential therapeutic targets.


Subject(s)
Biomarkers, Tumor/biosynthesis , Biomarkers, Tumor/deficiency , Mucins/biosynthesis , PTEN Phosphohydrolase/deficiency , Prostatic Neoplasms, Castration-Resistant/metabolism , Animals , Biomarkers, Tumor/genetics , Databases, Genetic , Male , Metaplasia/genetics , Metaplasia/metabolism , Metaplasia/pathology , Mice , Mice, Knockout , Mice, Transgenic , Mucins/genetics , PTEN Phosphohydrolase/genetics , Prognosis , Prostatic Neoplasms, Castration-Resistant/genetics , Prostatic Neoplasms, Castration-Resistant/pathology
7.
Nat Commun ; 13(1): 182, 2022 01 10.
Article in English | MEDLINE | ID: mdl-35013322

ABSTRACT

Combining immune checkpoint therapy (ICT) and targeted therapy holds great promises for broad and long-lasting anti-cancer therapies. However, combining ICT with anti-PI3K inhibitors have been challenging because the multifaceted effects of PI3K on both cancer cells and immune cells within the tumor microenvironment. Here we find that intermittent but not daily dosing of a PI3Kα/ß/δ inhibitor, BAY1082439, on Pten-null prostate cancer models could overcome ICT resistance and unleash CD8+ T cell-dependent anti-tumor immunity in vivo. Mechanistically, BAY1082439 converts cancer cell-intrinsic immune-suppression to immune-stimulation by promoting IFNα/IFNγ pathway activation, ß2-microglubin expression and CXCL10/CCL5 secretion. With its preferential regulatory T cell inhibition activity, BAY1082439 promotes clonal expansion of tumor-associated CD8+ T cells, most likely via tertiary lymphoid structures. Once primed, tumors remain T cell-inflamed, become responsive to anti-PD-1 therapy and have durable therapeutic effect. Our data suggest that intermittent PI3K inhibition can alleviate Pten-null cancer cell-intrinsic immunosuppressive activity and turn "cold" tumors into T cell-inflamed ones, paving the way for successful ICT.


Subject(s)
Antibodies, Neutralizing/pharmacology , Antineoplastic Agents, Immunological/pharmacology , Class I Phosphatidylinositol 3-Kinases/genetics , Immune Checkpoint Inhibitors/pharmacology , PTEN Phosphohydrolase/genetics , Programmed Cell Death 1 Receptor/genetics , Prostatic Neoplasms, Castration-Resistant/drug therapy , Animals , CD8-Positive T-Lymphocytes/drug effects , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/pathology , Cell Line, Tumor , Cell Movement/drug effects , Chemokine CCL5/genetics , Chemokine CCL5/immunology , Chemokine CXCL10/genetics , Chemokine CXCL10/immunology , Class I Phosphatidylinositol 3-Kinases/immunology , Disease Models, Animal , Drug Resistance, Neoplasm/drug effects , Drug Resistance, Neoplasm/genetics , Drug Resistance, Neoplasm/immunology , Gene Expression Regulation, Neoplastic , Humans , Interferon-alpha/genetics , Interferon-alpha/immunology , Interferon-gamma/genetics , Interferon-gamma/immunology , Male , Mice , Mice, Knockout , PTEN Phosphohydrolase/deficiency , PTEN Phosphohydrolase/immunology , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Programmed Cell Death 1 Receptor/immunology , Prostate/drug effects , Prostate/metabolism , Prostate/pathology , Prostatic Neoplasms, Castration-Resistant/genetics , Prostatic Neoplasms, Castration-Resistant/metabolism , Prostatic Neoplasms, Castration-Resistant/pathology , Signal Transduction , Tumor Microenvironment/drug effects , Tumor Microenvironment/genetics , Tumor Microenvironment/immunology , beta 2-Microglobulin/genetics , beta 2-Microglobulin/immunology
8.
Virology ; 566: 16-25, 2022 01.
Article in English | MEDLINE | ID: mdl-34844082

ABSTRACT

Chronic HBV infection is a major cause of hepatocellular carcinoma (HCC) worldwide. The phenotypes of HCC are diverse, in part, due to mutations in distinct oncogenes and/or tumor suppressor genes. These genetic drivers of HCC development have generally been considered as major mediators of tumor heterogeneity. Using the liver-specific Pten-null HBV transgenic mouse model of chronic viral infection, a critical role for liver lobule zone-specific gene expression patterns in determining HCC phenotype and ß-catenin-dependent HBV biosynthesis is demonstrated. These observations suggest that the position of the hepatocyte within the liver lobule, and hence its intrinsic gene expression pattern at the time of cellular transformation, make critical contributions to the properties of the resulting liver tumor. These results may explain why therapies targeting pathways modulated by specific identified tumor driver genes display variable treatment efficacy.


Subject(s)
Carcinoma, Hepatocellular/genetics , Cell Transformation, Neoplastic/genetics , Hepatitis B virus/genetics , Hepatitis B/genetics , Hepatocytes/metabolism , Liver Neoplasms/genetics , beta Catenin/genetics , Animals , Carcinoma, Hepatocellular/metabolism , Carcinoma, Hepatocellular/pathology , Carcinoma, Hepatocellular/virology , Cell Transformation, Neoplastic/metabolism , Female , Gene Expression Regulation, Neoplastic , Genetic Heterogeneity , Hepatitis B/metabolism , Hepatitis B/pathology , Hepatitis B/virology , Hepatitis B virus/metabolism , Hepatitis B virus/pathogenicity , Hepatocytes/virology , Hepcidins/genetics , Hepcidins/metabolism , Humans , Intercellular Signaling Peptides and Proteins/genetics , Intercellular Signaling Peptides and Proteins/metabolism , Lipocalin-2/genetics , Lipocalin-2/metabolism , Liver/metabolism , Liver/virology , Liver Neoplasms/metabolism , Liver Neoplasms/pathology , Liver Neoplasms/virology , Male , Mice , Mice, Transgenic , Ornithine-Oxo-Acid Transaminase/genetics , Ornithine-Oxo-Acid Transaminase/metabolism , PTEN Phosphohydrolase/deficiency , PTEN Phosphohydrolase/genetics , Phenotype , Signal Transduction , T-Box Domain Proteins/genetics , T-Box Domain Proteins/metabolism , Virus Replication , beta Catenin/metabolism
9.
FASEB J ; 35(10): e21943, 2021 10.
Article in English | MEDLINE | ID: mdl-34582065

ABSTRACT

Neural cells are continuously subjected to oxidative stress arising from electrochemical activity, and cellular protection systems can turn on the oxidative stress response to detect and alleviate adverse conditions. However, the function and mechanism of the protective systems are complicated and remain largely elusive. We report that PTENα, an isoform of the PTEN family, mediates defense signaling in response to oxidative stress during brain aging. We show that genetic ablation of Ptenα in mice increases oxidative stress and results in neuronal cell death, culminating in accelerated decline of cognition and motor coordination as age increases. PTENα maintains COX activity and promotes energy metabolism through abrogating NEDD4L-mediated degradation of COX4 in response to oxidative stress. In the presence of Parkinson's disease-associated mutation, PTENα loses the capability to protect COX4 and ameliorate defects caused by Ptenα deletion. Our study reveals an important role of PTENα in response to oxidative stress. We propose that dysregulation of PTENα signaling may accelerate the rate of brain aging and promote the development of neurodegenerative disorders.


Subject(s)
Aging/metabolism , Brain/metabolism , Oxidative Stress , PTEN Phosphohydrolase/metabolism , Aging/genetics , Animals , Brain/cytology , Cell Line , Electron Transport Complex IV/metabolism , Humans , Male , Mice , Nedd4 Ubiquitin Protein Ligases/metabolism , Neurons/metabolism , PTEN Phosphohydrolase/chemistry , PTEN Phosphohydrolase/deficiency , PTEN Phosphohydrolase/genetics
10.
Nat Commun ; 12(1): 5520, 2021 09 17.
Article in English | MEDLINE | ID: mdl-34535684

ABSTRACT

PTEN promoter hypermethylation is nearly universal and PTEN copy number loss occurs in ~25% of fusion-negative rhabdomyosarcoma (FN-RMS). Here we show Pten deletion in a mouse model of FN-RMS results in less differentiated tumors more closely resembling human embryonal RMS. PTEN loss activated the PI3K pathway but did not increase mTOR activity. In wild-type tumors, PTEN was expressed in the nucleus suggesting loss of nuclear PTEN functions could account for these phenotypes. Pten deleted tumors had increased expression of transcription factors important in neural and skeletal muscle development including Dbx1 and Pax7. Pax7 deletion completely rescued the effects of Pten loss. Strikingly, these Pten;Pax7 deleted tumors were no longer FN-RMS but displayed smooth muscle differentiation similar to leiomyosarcoma. These data highlight how Pten loss in FN-RMS is connected to a PAX7 lineage-specific transcriptional output that creates a dependency or synthetic essentiality on the transcription factor PAX7 to maintain tumor identity.


Subject(s)
PAX7 Transcription Factor/metabolism , PTEN Phosphohydrolase/metabolism , Rhabdomyosarcoma/metabolism , Rhabdomyosarcoma/pathology , Animals , Breeding , Cell Differentiation , Cell Line, Tumor , Gene Expression Regulation, Neoplastic , Homeodomain Proteins/metabolism , Humans , Integrases/metabolism , Mechanistic Target of Rapamycin Complex 1/metabolism , Mice, Knockout , Muscle Development , PTEN Phosphohydrolase/deficiency , Phosphoproteins/metabolism , Proto-Oncogene Proteins c-akt/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rhabdomyosarcoma/genetics
11.
Nat Commun ; 12(1): 5053, 2021 08 20.
Article in English | MEDLINE | ID: mdl-34417459

ABSTRACT

Previous studies have suggested that PTEN loss is associated with p110ß signaling dependency, leading to the clinical development of p110ß-selective inhibitors. Here we use a panel pre-clinical models to reveal that PI3K isoform dependency is not governed by loss of PTEN and is impacted by feedback inhibition and concurrent PIK3CA/PIK3CB alterations. Furthermore, while pan-PI3K inhibition in PTEN-deficient tumors is efficacious, upregulation of Insulin Like Growth Factor 1 Receptor (IGF1R) promotes resistance. Importantly, we show that this resistance can be overcome through targeting AKT and we find that AKT inhibitors are superior to pan-PI3K inhibition in the context of PTEN loss. However, in the presence of wild-type PTEN and PIK3CA-activating mutations, p110α-dependent signaling is dominant and selectively inhibiting p110α is therapeutically superior to AKT inhibition. These discoveries reveal a more nuanced understanding of PI3K isoform dependency and unveil novel strategies to selectively target PI3K signaling nodes in a context-specific manner.


Subject(s)
Phosphatidylinositol 3-Kinases/metabolism , Prostatic Neoplasms/drug therapy , Prostatic Neoplasms/enzymology , Signal Transduction , Animals , Cell Line, Tumor , Feedback, Physiological , Humans , Isoenzymes/metabolism , Male , Mice , Models, Biological , Organoids/drug effects , Organoids/metabolism , PTEN Phosphohydrolase/deficiency , PTEN Phosphohydrolase/metabolism , Phosphorylation/drug effects , Protein Kinase Inhibitors/pharmacology , Receptor, IGF Type 1/metabolism , Up-Regulation/drug effects
12.
Mol Cells ; 44(8): 613-622, 2021 Aug 31.
Article in English | MEDLINE | ID: mdl-34376625

ABSTRACT

In vertebrate eyes, the retinal pigment epithelium (RPE) provides structural and functional homeostasis to the retina. The RPE takes up retinol (ROL) to be dehydrogenated and isomerized to 11-cis-retinaldehyde (11-cis-RAL), which is a functional photopigment in mammalian photoreceptors. As excessive ROL is toxic, the RPE must also establish mechanisms to protect against ROL toxicity. Here, we found that the levels of retinol dehydrogenases (RDHs) are commonly decreased in phosphatase tensin homolog (Pten)-deficient mouse RPE, which degenerates due to elevated ROL and that can be rescued by feeding a ROL-free diet. We also identified that RDH gene expression is regulated by forkhead box O (FOXO) transcription factors, which are inactivated by hyperactive Akt in the Pten-deficient mouse RPE. Together, our findings suggest that a homeostatic pathway comprising PTEN, FOXO, and RDH can protect the RPE from ROL toxicity.


Subject(s)
PTEN Phosphohydrolase/deficiency , Retinal Degeneration/pathology , Retinal Pigment Epithelium/metabolism , Retinal Pigment Epithelium/pathology , Retinoids/metabolism , Alcohol Oxidoreductases/metabolism , Aldehyde Dehydrogenase/metabolism , Animals , Diet , Forkhead Transcription Factors/metabolism , Mice, Transgenic , PTEN Phosphohydrolase/metabolism , Retinal Degeneration/metabolism , Vitamin A/metabolism
14.
J Control Release ; 334: 335-352, 2021 06 10.
Article in English | MEDLINE | ID: mdl-33933518

ABSTRACT

Phosphatase and TENsin homolog deleted on chromosome 10 (PTEN) is a major tumor-suppressor protein that is lost in up to 75% of aggressive colorectal cancers (CRC). The co-depletion of PTEN and a DNA repair protein, polynucleotide kinase 3'-phosphatase (PNKP), has been shown to lead to synthetic lethality in several cancer types including CRC. This finding inspired the development of novel PNKP inhibitors as potential new drugs against PTEN-deficient CRC. Here, we report on the in vitro and in vivo evaluation of a nano-encapsulated potent, but poorly water-soluble lead PNKP inhibitor, A83B4C63, as a new targeted therapeutic for PTEN-deficient CRC. Our data confirmed the binding of A83B4C63, as free or nanoparticle (NP) formulation, to intracellular PNKP using the cellular thermal shift assay (CETSA), in vitro and in vivo. Dose escalating toxicity studies in healthy CD-1 mice, based on measurement of animal weight changes and biochemical blood analysis, revealed the safety of both free and nano-encapsulated A83B4C63, at assessed doses of ≤50 mg/kg. Nano-carriers of A83B4C63 effectively inhibited the growth of HCT116/PTEN-/- xenografts in NIH-III nude mice following intravenous (IV) administration, but not that of wild-type HCT116/PTEN+/+ xenografts. This was in contrast to IV administration of A83B4C63 solubilized with the aid of Cremophor EL: Ethanol (CE), which led to similar tumor growth to that of formulation excipients (NP or CE without drug) or 5% dextrose. This observation was attributed to the higher levels of A83B4C63 delivered to tumor tissue by its NP formulation. Our data provide evidence for the success of NPs of A83B4C63, as novel synthetically lethal nano-therapeutics in the treatment of PTEN-deficient CRC. This research also highlights the potential of successful application of nanomedicine in the drug development process.


Subject(s)
Colorectal Neoplasms , Polynucleotide 5'-Hydroxyl-Kinase , Animals , Colorectal Neoplasms/drug therapy , Mice , Mice, Nude , Nanomedicine , PTEN Phosphohydrolase/deficiency , Phosphotransferases (Alcohol Group Acceptor)/antagonists & inhibitors
15.
J Clin Invest ; 131(13)2021 07 01.
Article in English | MEDLINE | ID: mdl-34032634

ABSTRACT

The role of PI3K and Hippo signaling in chronic pancreatitis (CP) pathogenesis is unclear. Therefore, we assessed the involvement of these pathways in CP by examining the PI3K and Hippo signaling components PTEN and SAV1, respectively. We observed significant decreases in pancreatic PTEN and SAV1 levels in 2 murine CP models: repeated cerulein injection and pancreatic ductal ligation. Additionally, pancreas-specific deletion of Pten and Sav1 (DKO) induced CP in mice. Pancreatic connective tissue growth factor (CTGF) was markedly upregulated in both CP models and DKO mice, and pancreatic CCAAT/enhancer-binding protein-α (CEBPA) expression was downregulated in the CP models. Interestingly, in pancreatic acinar cells (PACs), CEBPA knockdown reduced PTEN and SAV1 and increased CTGF levels in vitro. Furthermore, CEBPA knockdown in PACs induced acinar-to-ductal metaplasia and activation of cocultured macrophages and pancreatic stellate cells. These results were mitigated by CTGF inhibition. CP in DKO mice was also ameliorated by Ctgf gene deletion, and cerulein-induced CP was alleviated by antibody-mediated CTGF neutralization. Finally, we observed significantly decreased PTEN, SAV1, and CEBPA and increased CTGF levels in human CP tissues compared with nonpancreatitis tissues. Taken together, our results indicate that dysregulation of PI3K and Hippo signaling induces CP via CTGF upregulation.


Subject(s)
Connective Tissue Growth Factor/metabolism , Pancreatitis, Chronic/etiology , Pancreatitis, Chronic/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Protein Serine-Threonine Kinases/metabolism , Animals , CCAAT-Enhancer-Binding Proteins/deficiency , CCAAT-Enhancer-Binding Proteins/genetics , CCAAT-Enhancer-Binding Proteins/metabolism , Cell Cycle Proteins/deficiency , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , Ceruletide/toxicity , Coculture Techniques , Connective Tissue Growth Factor/antagonists & inhibitors , Connective Tissue Growth Factor/genetics , Disease Models, Animal , Down-Regulation , Hippo Signaling Pathway , Humans , Macrophages/metabolism , Macrophages/pathology , Mice , Mice, Inbred C57BL , Mice, Knockout , PTEN Phosphohydrolase/deficiency , PTEN Phosphohydrolase/genetics , PTEN Phosphohydrolase/metabolism , Pancreatic Stellate Cells/metabolism , Pancreatic Stellate Cells/pathology , Pancreatitis, Chronic/pathology , Signal Transduction , Up-Regulation
16.
Cell Prolif ; 54(7): e13056, 2021 Jul.
Article in English | MEDLINE | ID: mdl-34021647

ABSTRACT

OBJECTIVES: In contrast to extensive studies on bone metastasis in advanced prostate cancer (PCa), liver metastasis has been under-researched so far. In order to decipher molecular and cellular mechanisms underpinning liver metastasis of advanced PCa, we develop a rapid and immune sufficient mouse model for liver metastasis of PCa via orthotopic injection of organoids from PbCre+ ; rb1f/f ;p53f/f mice. MATERIALS AND METHODS: PbCre+ ;rb1f/f ;p53f/f and PbCre+ ;ptenf/f ;p53f/f mice were used to generate PCa organoid cultures in vitro. Immune sufficient liver metastasis models were established via orthotopic transplantation of organoids into the prostate of C57BL/6 mice. Immunofluorescent and immunohistochemical staining were performed to characterize the lineage profile in primary tumour and organoid-derived tumour (ODT). The growth of niche-labelling reporter infected ODT can be visualized by bioluminescent imaging system. Immune cells that communicated with tumour cells in the liver metastatic niche were determined by flow cytometry. RESULTS: A PCa liver metastasis model with full penetrance is established in immune-intact mouse. This model reconstitutes the histological and lineage features of original tumours and reveals dynamic tumour-immune cell communication in liver metastatic foci. Our results suggest that a lack of CD8+ T cell and an enrichment of CD163+ M2-like macrophage as well as PD1+ CD4+ T cell contribute to an immuno-suppressive microenvironment of PCa liver metastasis. CONCLUSIONS: Our model can be served as a reliable tool for analysis of the molecular pathogenesis and tumour-immune cell crosstalk in liver metastasis of PCa, and might be used as a valuable in vivo model for therapy development.


Subject(s)
Liver Neoplasms/pathology , Prostatic Neoplasms/pathology , Animals , CD4-Positive T-Lymphocytes/cytology , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/cytology , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , Cell Communication , Disease Models, Animal , Liver Neoplasms/secondary , Macrophages/cytology , Macrophages/immunology , Macrophages/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , PTEN Phosphohydrolase/deficiency , PTEN Phosphohydrolase/genetics , Prostatic Neoplasms/metabolism , Tumor Microenvironment , Tumor Suppressor Protein p53/deficiency , Tumor Suppressor Protein p53/genetics
17.
BMC Cancer ; 21(1): 429, 2021 Apr 19.
Article in English | MEDLINE | ID: mdl-33874915

ABSTRACT

BACKGROUND: Recent evidences had shown that loss in phosphatase and tensin homolog deleted on chromosome 10 (PTEN) was associated with immunotherapy resistance, which may be attributed to the non-T-cell-inflamed tumor microenvironment. The impact of PTEN loss on tumor microenvironment, especially regarding T cell infiltration across tumor types is not well understood. METHODS: Utilizing The Cancer Genome Atlas (TCGA) and publicly available dataset of immunotherapy, we explored the correlation of PTEN expressing level or genomic loss with tumor immune microenvironment and response to immunotherapy. We further investigated the involvement of PI3K-AKT-mTOR pathway activation, which is known to be the subsequent effect of PTEN loss, in the immune microenvironment modulation. RESULTS: We reveal that PTEN mRNA expression is significantly positively correlated with CD4/CD8A gene expression and T cells infiltration especially T helpers cells, central memory T cell and effector memory T cells in multiples tumor types. Genomic loss of PTEN is associated with reduced CD8+ T cells, type 1 T helper cells, and increased type 2 T helper cells, immunosuppressed genes (e.g. VEGFA) expression. Furthermore, T cell exclusive phenotype is also observed in tumor with PI3K pathway activation or genomic gain in PIK3CA or PIK3CB. PTEN loss and PI3K pathway activation correlate with immunosuppressive microenvironment, especially in terms of T cell exclusion. PTEN loss predict poor therapeutic response and worse survival outcome in patients receiving immunotherapy. CONCLUSION: These data brings insight into the role of PTEN loss in T cell exclusion and immunotherapy resistance, and inspires further research on immune modulating strategy to augment immunotherapy.


Subject(s)
Neoplasms/etiology , Neoplasms/metabolism , PTEN Phosphohydrolase/deficiency , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Antineoplastic Agents, Immunological/pharmacology , Antineoplastic Agents, Immunological/therapeutic use , Databases, Genetic , Disease Susceptibility , Gene Expression , Genomics/methods , Humans , Lymphocytes, Tumor-Infiltrating/immunology , Lymphocytes, Tumor-Infiltrating/metabolism , Lymphocytes, Tumor-Infiltrating/pathology , Molecular Targeted Therapy , Neoplasms/pathology , Neoplasms/therapy , PTEN Phosphohydrolase/genetics , PTEN Phosphohydrolase/metabolism , Phosphatidylinositol 3-Kinase/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , T-Lymphocyte Subsets/pathology , T-Lymphocytes/pathology , TOR Serine-Threonine Kinases/metabolism , Tumor Escape , Tumor Microenvironment
18.
Biochem Biophys Res Commun ; 549: 83-90, 2021 04 16.
Article in English | MEDLINE | ID: mdl-33667713

ABSTRACT

PTEN and p53 are highly mutated in many cancers. These two tumor suppressors have critical functions in the nucleus, such as DNA repair, cell cycle progression, and genome maintenance. However, the in vivo functional relationship of nuclear PTEN and p53 is unknown. Here, we analyzed the liver of mice in which nuclear PTEN and p53 are individually or simultaneously depleted. We found that nuclear PTEN loss greatly upregulates p53 expression upon oxidative stress, while the loss of p53 potentiates stress-induced accumulation of PTEN in the nucleus. Next, we examined oxidative stress-induced DNA damage in hepatocytes, and found that nuclear PTEN loss aggravated the damage while p53 loss did not. Notably, mice lacking nuclear PTEN had increased hepatocellular carcinoma under oxidative stress, while mice lacking p53 in hepatocytes had accelerated hepatocellular carcinoma and intrahepatic cholangiocarcinoma. The formation of cholangiocarcinoma appears to involve the transformation of hepatocytes into cholangiocarcinoma. Simultaneous loss of nuclear PTEN and p53 exacerbated both types of liver cancers. These data suggest that nuclear PTEN and p53 suppress liver cancers through distinct mechanisms.


Subject(s)
Cell Nucleus/metabolism , Liver Neoplasms/pathology , Oxidative Stress , PTEN Phosphohydrolase/metabolism , Tumor Suppressor Protein p53/metabolism , Animals , Bile Duct Neoplasms/pathology , Carcinogenesis/metabolism , Carcinogenesis/pathology , Cholangiocarcinoma/pathology , DNA Damage , Hepatocytes/metabolism , Liver Cirrhosis/pathology , Male , Mice, Knockout , PTEN Phosphohydrolase/deficiency , Tumor Suppressor Protein p53/deficiency , Up-Regulation
19.
Cell Death Dis ; 12(2): 172, 2021 02 10.
Article in English | MEDLINE | ID: mdl-33568640

ABSTRACT

As evidenced by the behavior of loss-of-function mutants of PTEN in the context of a gain-of-function mutation of AKT1, the PTEN-AKT1 signaling pathway plays a critical role in human cancers. In this study, we demonstrated that a deficiency in PTEN or activation of AKT1 potentiated the expression of platelet-derived growth factor receptor α (PDGFRα) based on studies on Pten-/- mouse embryonic fibroblasts, human cancer cell lines, the hepatic tissues of Pten conditional knockout mice, and human cancer tissues. Loss of PTEN enhanced PDGFRα expression via activation of the AKT1-CREB signaling cascade. CREB transactivated PDGFRα expression by direct binding of the promoter of the PDGFRα gene. Depletion of PDGFRα attenuated the tumorigenicity of Pten-null cells in nude mice. Moreover, the PI3K-AKT signaling pathway has been shown to positively correlate with PDGFRα expression in multiple cancers. Augmented PDGFRα was associated with poor survival of cancer patients. Lastly, combination treatment with the AKT inhibitor MK-2206 and the PDGFR inhibitor CP-673451 displayed synergistic anti-tumor effects. Therefore, activation of the AKT1-CREB-PDGFRα signaling pathway contributes to the tumor growth induced by PTEN deficiency and should be targeted for cancer treatment.


Subject(s)
Cell Proliferation , Cyclic AMP Response Element-Binding Protein/metabolism , Fibroblasts/enzymology , Liver/enzymology , Neoplasms/enzymology , PTEN Phosphohydrolase/deficiency , Proto-Oncogene Proteins c-akt/metabolism , Receptor, Platelet-Derived Growth Factor alpha/metabolism , Animals , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Benzimidazoles/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , Cyclic AMP Response Element-Binding Protein/genetics , Fibroblasts/drug effects , Fibroblasts/pathology , Gene Expression Regulation, Neoplastic , HEK293 Cells , Heterocyclic Compounds, 3-Ring/pharmacology , Humans , Liver/drug effects , Liver/pathology , Male , Mice, Inbred BALB C , Mice, Knockout , Mice, Nude , Neoplasms/drug therapy , Neoplasms/genetics , Neoplasms/pathology , PTEN Phosphohydrolase/genetics , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins c-akt/antagonists & inhibitors , Proto-Oncogene Proteins c-akt/genetics , Quinolines/pharmacology , Receptor, Platelet-Derived Growth Factor alpha/genetics , Signal Transduction , Xenograft Model Antitumor Assays
20.
Mol Brain ; 14(1): 24, 2021 01 27.
Article in English | MEDLINE | ID: mdl-33504340

ABSTRACT

Disrupted GABAergic neurons have been extensively described in brain tissues from individuals with autism spectrum disorder (ASD) and animal models for ASD. However, the contribution of these aberrant inhibitory neurons to autism-related behavioral phenotypes is not well understood. We examined ASD-related behaviors in mice with conditional Pten knockout in parvalbumin (PV)-expressing or somatostatin (Sst)-expressing neurons, two common subtypes of GABAergic neurons. We found that mice with deletion of Pten in either PV-neurons or Sst-neurons displayed social deficits, repetitive behaviors and impaired motor coordination/learning. In addition, mice with one copy of Pten deletion in PV-neurons exhibited hyperlocomotion in novel open fields and home cages. We also examined anxiety behaviors and found that mice with Pten deletion in Sst-neurons displayed anxiety-like behaviors, while mice with Pten deletion in PV-neurons exhibited anxiolytic-like behaviors. These behavioral assessments demonstrate that Pten knockout in the subtype of inhibitory neurons sufficiently gives rise to ASD-core behaviors, providing evidence that both PV- and Sst-neurons may play a critical role in ASD symptoms.


Subject(s)
Autistic Disorder/metabolism , Behavior, Animal , Neurons/metabolism , PTEN Phosphohydrolase/deficiency , Parvalbumins/metabolism , Somatostatin/metabolism , Animals , Anxiety/complications , Autistic Disorder/complications , Grooming , Mice, Inbred C57BL , Mice, Knockout , Motor Activity , PTEN Phosphohydrolase/metabolism , Phenotype , Social Behavior
SELECTION OF CITATIONS
SEARCH DETAIL