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1.
Clin Immunol ; 260: 109915, 2024 03.
Article in English | MEDLINE | ID: mdl-38286172

ABSTRACT

The increased risk for acquiring secondary illnesses in people living with HIV (PLWH) has been associated with immune dysfunction. We have previously found that circulating monocytes from PLWH display a trained phenotype. Here, we evaluated the metabolic profile of these cells and found increased mitochondrial respiration and glycolysis of monocyte-derived macrophages (MDMs) from PLWH. We additionally found that cART shifted the energy metabolism of MDMs from controls toward increased utilization of mitochondrial respiration. Importantly, both downregulation of IKAROS expression and inhibition of the mTOR pathway reversed the metabolic profile of MDMs from PLWH and cART-treated control-MDMs. Altogether, this study reveals a very specific metabolic adaptation of MDMs from PLWH, which involves an IKAROS/mTOR-dependent increase of mitochondrial respiration and glycolysis. We propose that this metabolic adaptation decreases the ability of these cells to respond to environmental cues by "locking" PLWH monocytes in a pro-inflammatory and activated phenotype.


Subject(s)
HIV Infections , Humans , Macrophages , Monocytes , Phenotype , TOR Serine-Threonine Kinases/metabolism
2.
Sci Rep ; 13(1): 12236, 2023 07 28.
Article in English | MEDLINE | ID: mdl-37507404

ABSTRACT

Glioblastomas are highly aggressive brain tumors for which therapeutic options are very limited. In a quest for new anti-glioblastoma drugs, we focused on specific structural modifications to the benzoyl-phenoxy-acetamide (BPA) structure present in a common lipid-lowering drug, fenofibrate, and in our first prototype glioblastoma drug, PP1. Here, we propose extensive computational analyses to improve the selection of the most effective glioblastoma drug candidates. Initially, over 100 structural BPA variations were analyzed and their physicochemical properties, such as water solubility (- logS), calculated partition coefficient (ClogP), probability for BBB crossing (BBB_SCORE), probability for CNS penetration (CNS-MPO) and calculated cardiotoxicity (hERG), were evaluated. This integrated approach allowed us to select pyridine variants of BPA that show improved BBB penetration, water solubility, and low cardiotoxicity. Herein the top 24 compounds were synthesized and analyzed in cell culture. Six of them demonstrated glioblastoma toxicity with IC50 ranging from 0.59 to 3.24 µM. Importantly, one of the compounds, HR68, accumulated in the brain tumor tissue at 3.7 ± 0.5 µM, which exceeds its glioblastoma IC50 (1.17 µM) by over threefold.


Subject(s)
Brain Neoplasms , Glioblastoma , Humans , Blood-Brain Barrier , Cardiotoxicity , Glioblastoma/drug therapy , Glioblastoma/pathology , Brain Neoplasms/drug therapy , Computer Simulation , Acetamides/pharmacology , Pyridines/pharmacology , Water/pharmacology , Cell Line, Tumor
3.
J Infect Dis ; 228(10): 1385-1393, 2023 11 11.
Article in English | MEDLINE | ID: mdl-37161924

ABSTRACT

BACKGROUND: Most cervical cancers are directly linked to oncogenic or high-risk human papillomavirus (HR-HPV) infection. This study evaluates associations between diet quality and genital HPV infection in women. METHODS: This study included 10 543 women from the 2003-2016 National Health and Nutrition Examination Survey. The outcome was the genital HPV infection status (HPV-negative, low-risk [LR] HPV, and HR-HPV). Dietary quality was evaluated using the Healthy Eating Index (HEI), in which a higher score indicates a better diet quality. RESULTS: Women who did not consume total fruits (15.8%), whole fruits (27.5%), or green vegetables and beans (43%) had a significantly higher risk of HR-HPV infection than women who complied with the Dietary Guidelines for Americans (HR-HPV odds ratio = 1.76, 1.63, and 1.48 for a HEI score of 0 vs 5, respectively) after adjusting confounding factors. Similar results of these food components on LR-HPV infection were found. In addition, intake of whole grains and dairy was inversely associated with LR-HPV infection. CONCLUSIONS: This study showed that women who did not eat fruits, dark-green vegetables, and beans had a higher risk of genital HR-HPV infection. Intake of these food components is suggested for women to prevent HPV carcinogenesis.


Subject(s)
Papillomavirus Infections , Uterine Cervical Neoplasms , Humans , Female , Papillomavirus Infections/epidemiology , Human Papillomavirus Viruses , Nutrition Surveys , Diet
4.
Res Sq ; 2023 Apr 20.
Article in English | MEDLINE | ID: mdl-37131829

ABSTRACT

Glioblastomas are highly aggressive brain tumors for which therapeutic options are very limited. In a quest for new anti-glioblastoma drugs, we focused on specific structural modifications of benzoyl-phenoxy-acetamide (BPA) present in a common lipid-lowering drug, fenofibrate, and in our first prototype glioblastoma drug, PP1. Here, we propose extensive computational analyses to improve selection of the most effective glioblastoma drug candidates. Initially over 100 structural BPA variations were analyzed and their physicochemical properties such as water solubility (-logS), calculated partition coefficient (ClogP), probability for BBB crossing (BBB_SCORE), probability for CNS penetration (CNS-MPO) and calculated cardiotoxicity (hERG), were evaluated. This integrated approach allowed us to select pyridine variants of BPA that show improved BBB penetration, water solubility, and low cardiotoxicity. Herein the top 24 compounds were synthesized and analyzed in cell culture. Six of them demonstrated glioblastoma toxicity with IC50 ranging from 0.59 to 3.24mM. Importantly, one of the compounds, HR68, accumulated in the brain tumor tissue at 3.7+/-0.5mM, which exceeds its glioblastoma IC50 (1.17mM) by over 3-fold.

5.
Cancer Cell Int ; 22(1): 204, 2022 May 31.
Article in English | MEDLINE | ID: mdl-35642054

ABSTRACT

BACKGROUND: Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer characterized by the lack of estrogen receptor, progesterone receptor, and HER2. Our lab previously characterized miR-3189-3p as a microRNA with potent anti-cancer activity against glioblastoma. Here, we hypothesized a similar activity in TNBC cells. As miR-3189-3p is predicted to target a variety of RNA binding proteins, we further hypothesized an inhibitory effect of this miRNA on protein synthesis. METHODS: MDA-MB-231 and MDA-MB-468 cells were used to investigate the effect of miR-3189-3p on cell proliferation, migration, and invasion. TGCA database was used to analyze the expression of miR-3189-3p, c-MYC, 4EPB1, and eIF4E in breast cancer. Western blotting and RT-qPCR assays were used to assess the expression of selected proteins and RNAs after transfections. RESULTS: Although c-MYC is not a predicted gene target for miR-3189-3p, we discovered that c-MYC protein is downregulated in miRNA-treated TNBC cells. We found that the downregulation of c-MYC by miR-3189-3p occurs in both normal growth conditions and in the absence of serum. The mechanism involved the direct inhibition of eIF4EBP1 by miR-3189-3p. Additionally, we found that miR-3189-3p could negatively affect cap-independent translation mediated by internal ribosome entry sites (IRES) or by m6A. Finally, miR-3189-3p sensitized TNBC cells to doxorubicin. CONCLUSION: Overall, results indicated that miR-3189-3p exerts its anti-tumor activity through targeting translational regulatory proteins leading to an impairment in c-MYC translation, and possibly other oncogenic factors, suggesting that miR-3189-3p, alone or in combination, could be a valuable therapeutic approach against a malignancy with few treatment options.

6.
Sci Rep ; 12(1): 3384, 2022 03 01.
Article in English | MEDLINE | ID: mdl-35232976

ABSTRACT

Glioblastomas are the most aggressive brain tumors for which therapeutic options are limited. Current therapies against glioblastoma include surgical resection, followed by radiotherapy plus concomitant treatment and maintenance with temozolomide (TMZ), however, these standard therapies are often ineffective, and average survival time for glioblastoma patients is between 12 and 18 months. We have previously reported a strong anti-glioblastoma activity of several metabolic compounds, which were synthetized based compounds, which were synthetized based on the chemical structure of a common lipid-lowering drug, fenofibrate, and share a general molecular skeleton of benzoylphenoxyacetamide (BPA). Extensive computational analyses of phenol and naphthol moieties added to the BPA skeleton were performed in this study with the objective of selecting new BPA variants for subsequent compound preparation and anti-glioblastoma testing. Initially, 81 structural variations were considered and their physical properties such as solubility (logS), blood-brain partitioning (logBB), and probability of entering the CNS calculated by the Central Nervous System-Multiparameter Optimization (MPO-CNS) algorithm were evaluated. From this initial list, 18 compounds were further evaluated for anti-glioblastoma activity in vitro. Nine compounds demonstrated desirable glioblastoma cell toxicity in cell culture, and two of them, HR51, and HR59 demonstrated significantly improved capability of crossing the model blood-brain-barrier (BBB) composed of endothelial cells, astrocytes and pericytes.


Subject(s)
Brain Neoplasms , Glioblastoma , Antineoplastic Agents, Alkylating/pharmacology , Blood-Brain Barrier/metabolism , Brain Neoplasms/pathology , Endothelial Cells/metabolism , Glioblastoma/pathology , Humans , Temozolomide/pharmacology
7.
Methods Mol Biol ; 2422: 147-161, 2022.
Article in English | MEDLINE | ID: mdl-34859404

ABSTRACT

Fluorescent immunocytochemistry is a powerful technique based on detecting antigens. It leads to discoveries in cell composition and structure as well as its functioning by expanding knowledge on colocalization between its components. The potency of this method is based on findings in the areas of specific antibodies production, fluorescent labels, and microscopy. Since it merges different fields, it requires basic knowledge on all the steps that are needed in the procedure planning and implementation to be used properly and produce reliable results. Here we describe a protocol of LN-229 human glioblastoma cells double labeling of LC3 and IRS-1 proteins, highlighting the importance of some steps of the procedure and possible variables.


Subject(s)
Immunohistochemistry , Antigens , Coloring Agents , Fluorescent Antibody Technique , Humans
8.
Methods Mol Biol ; 2422: 217-232, 2022.
Article in English | MEDLINE | ID: mdl-34859409

ABSTRACT

Cell cultures constitute an important tool for research as a way to reproduce pathological processes in a controlled system. However, the culture of brain-derived cells in monolayer presents significant challenges that obscure the fidelity of in vitro results. After a few number of passages, glial and neuronal cells begin to lose their morphological characteristics, and most importantly, their specific cellular markers and phenotype. In recent years, the discovery of neural progenitor cells, and the methodology to culture them in suspension maintaining their potentiality while still retaining the ability to differentiate into astrocytes, oligodendrocytes and neurons has been a significant contribution to the fields of neuroscience and neuropathology.In the brain, progenitor cells are located in the Germinal Matrix, the subventricular zone in what later would become the basal ganglia, and play an essential role in the homeostasis of the brain by providing the source to replace differentiated cells that have been lost or damaged by different pathological processes, such as senescence, injury, genetic conditions, or disease. The discovery of these neural stem cells in an organ traditionally thought to have limited or no regenerative capacity has opened the door to the development of novel treatments, which include cell replacement therapy. Here we describe the culture and differentiation of neural progenitor cells into neurospheres, and the phenotyping of the resulting cells using immunocytochemistry . The immunocytological methods outlined are not restricted to the analysis of neurosphere-derived cultures but are also applicable for cell typing of primary glial or cell line-derived samples.


Subject(s)
Neuroglia , Cell Culture Techniques , Cell Differentiation , Cells, Cultured , Neural Stem Cells , Neurons
9.
Methods Mol Biol ; 2422: 263-269, 2022.
Article in English | MEDLINE | ID: mdl-34859412

ABSTRACT

DNA damage is a common event that occurs during the life span of the majority of cells, as a result of aberrant energy metabolism, exposure to radiation, DNA damaging chemicals, and viral infections. Rapid, sensitive, and economical methods for the detection of DNA damage offer valuable insights into DNA repair, drug genotoxicity, and biomonitoring. The comet assay, or single cell electrophoresis, has emerged as a popular method for detecting single- and double-stranded DNA breaks in single cells. This experimental technique is based on the fact that, when exposed to an electric current, damaged DNA fragments in a gel, migrate farther from the nucleus toward the anode resulting in the shape of a comet. This assay is versatile, quantitative, simple to perform and exhibits high sensitivity; however, consistent experimental conditions must be maintained to ensure assay reproducibility. Electrophoresis can be performed under neutral conditions to detect solely double stranded breaks, or under alkaline conditions to detect both single- and double-stranded breaks. This chapter describes the protocol for both alkaline and neutral comet assays.


Subject(s)
Comet Assay , DNA Damage , DNA , DNA Breaks, Double-Stranded , Reproducibility of Results
10.
Front Immunol ; 12: 785905, 2021.
Article in English | MEDLINE | ID: mdl-34917094

ABSTRACT

Persons living with HIV (PLWH) are at higher risk of developing secondary illnesses than their uninfected counterparts, suggestive of a dysfunctional immune system in these individuals. Upon exposure to pathogens, monocytes undergo epigenetic remodeling that results in either a trained or a tolerant phenotype, characterized by hyper-responsiveness or hypo-responsiveness to secondary stimuli, respectively. We utilized CD14+ monocytes from virally suppressed PLWH and healthy controls for in vitro analysis following polarization of these cells toward a pro-inflammatory monocyte-derived macrophage (MDM) phenotype. We found that in PLWH-derived MDMs, pro-inflammatory signals (TNFA, IL6, IL1B, miR-155-5p, and IDO1) dominate over negative feedback signals (NCOR2, GSN, MSC, BIN1, and miR-146a-5p), favoring an abnormally trained phenotype. The mechanism of this reduction in negative feedback involves the attenuated expression of IKZF1, a transcription factor required for de novo synthesis of RELA during LPS-induced inflammatory responses. Furthermore, restoring IKZF1 expression in PLWH-MDMs partially reinstated expression of negative regulators of inflammation and lowered the expression of pro-inflammatory cytokines. Overall, this mechanism may provide a link between dysfunctional immune responses and susceptibility to co-morbidities in PLWH with low or undetectable viral load.


Subject(s)
Disease Susceptibility/immunology , HIV Infections/immunology , Ikaros Transcription Factor/metabolism , Macrophages/immunology , Transcription Factor RelA/metabolism , Anti-HIV Agents/administration & dosage , Case-Control Studies , Cytokines/metabolism , Feedback, Physiological , Female , Gene Expression Regulation/immunology , HIV/immunology , HIV/isolation & purification , HIV Infections/blood , HIV Infections/drug therapy , HIV Infections/virology , Healthy Volunteers , Humans , Inflammation/blood , Inflammation/immunology , Lipopolysaccharides/immunology , Macrophages/metabolism , Male , Middle Aged , Signal Transduction/drug effects , Signal Transduction/immunology , Transcription Factor RelA/genetics , Viral Load/drug effects , Viral Load/immunology
12.
J Infect Dis ; 224(9): 1520-1528, 2021 11 16.
Article in English | MEDLINE | ID: mdl-33735375

ABSTRACT

BACKGROUND: Human papillomavirus (HPV) infection is a major cause of cervical cancer. Studies showed the onset of HPV carcinogenesis may be induced by oxidative stress affecting the host immune system. The association between antioxidants and oncogenic HPV remains unclear. In this study, we aim to identify antioxidants associated with vaginal HPV infection in women. METHODS: The associations between the 15 antioxidants and vaginal HPV infection status (no, low-risk [LR], and high-risk [HR] HPV) were evaluated using 11 070 women who participated in the 2003-2016 National Health and Nutrition Examination Survey (NHANES). RESULTS: We identified serum albumin and 4 dietary antioxidants (vitamin A, B2, E, and folate) inversely associated with HR-HPV infection. Women with a low level of albumin (≤39 g/L) have a significantly higher risk of HR-HPV (odds ratio [OR] = 1.4, P = .009 vs >44 g/L). A Nutritional Antioxidant Score (NAS) was developed based on these 4 dietary antioxidants. The women with the lowest quartile NAS had a higher chance of HR-HPV (OR = 1.3, P = .030) and LR-HPV (OR = 1.4, P = .002) compared with the women with the highest quartile NAS. CONCLUSIONS: We identified 5 antioxidants negatively associated with vaginal HR-HPV infection in women. Our findings provide valuable insights into understanding antioxidants' impact on HPV carcinogenesis.


Subject(s)
Antioxidants/metabolism , DNA, Viral/genetics , Papillomaviridae/isolation & purification , Papillomavirus Infections/prevention & control , Uterine Cervical Neoplasms/prevention & control , Vagina/virology , Adolescent , Adult , Carcinogenesis , Female , Genotype , Humans , Middle Aged , Nutrition Surveys , Oxidative Stress , Papillomavirus Infections/epidemiology , Papillomavirus Infections/virology , Prevalence , United States/epidemiology , Uterine Cervical Neoplasms/epidemiology , Uterine Cervical Neoplasms/virology
13.
Exp Dermatol ; 29(4): 436-445, 2020 04.
Article in English | MEDLINE | ID: mdl-31957066

ABSTRACT

Development and progression of melanoma can be accelerated by intensification of particular metabolic pathways, such as aerobic glycolysis and avid amino acid catabolism, and is accompanied by aberrant immune responses within the tumor microenvironment. Contrary to other cancer types, melanoma reveals some unique tissue-specific features, such as melanogenesis, which is intertwined with metabolism. Nuclear peroxisome proliferator-activated receptors (PPARs) take part in regulation of systemic and cellular metabolism, inflammation and melanogenesis. They appear as a focal regulatory point for these three distinct processes by occupying the intersection among AMP-dependent protein kinase (AMPK), mammalian target of rapamycin (mTOR) and PPAR gamma coactivator 1-alpha (PGC-1α) signalling pathways. When deregulated, they may accelerate melanoma malignant growth. Presenting the contribution of PPARα and PPARγ in melanoma biology, we attempt to ask how two contrasting metabolic states: obesity and fasting, can change progression of the disease and possible outcome of the treatment. This short essay is aimed to provoke a discussion about some practical implications for melanoma prevention and treatment, especially: how metabolic manipulation may be exploited to overcome immunosuppression and support immune checkpoint blockade efficacy.


Subject(s)
Melanocytes/metabolism , Melanoma/metabolism , PPAR alpha/metabolism , Skin Neoplasms/metabolism , 3-Hydroxybutyric Acid/chemistry , Acetoacetates/chemistry , Animals , Arginine , Cell Nucleus/metabolism , Humans , Immune System , Immunotherapy/methods , Inflammation , Models, Theoretical , Obesity/metabolism , PPAR gamma/metabolism , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism , Signal Transduction , TOR Serine-Threonine Kinases/metabolism , Tumor Microenvironment
14.
Sci Rep ; 9(1): 17021, 2019 11 19.
Article in English | MEDLINE | ID: mdl-31745126

ABSTRACT

Structural variations of the benzylphenoxyacetamide (BPA) molecular skeleton were explored as a viable starting point for designing new anti-glioblastoma drug candidates. Hand-to-hand computational evaluation, chemical modifications, and cell viability testing were performed to explore the importance of some of the structural properties in order to generate, retain, and improve desired anti-glioblastoma characteristics. It was demonstrated that several structural features are required to retain the anti-glioblastoma activity, including a carbonyl group of the benzophenone moiety, as well as 4'-chloro and 2,2-dimethy substituents. In addition, the structure of the amide moiety can be modified in such a way that desirable anti-glioblastoma and physical properties can be improved. Via these structural modifications, more than 50 compounds were prepared and tested for anti-glioblastoma activity. Four compounds were identified (HR28, HR32, HR37, and HR46) that in addition to HR40 (PP1) from our previous study, have been determined to have desirable physical and biological properties. These include high glioblastoma cytotoxicity at low µM concentrations, improved water solubility, and the ability to penetrate the blood brain barrier (BBB), which indicate a potential for becoming a new class of anti-glioblastoma drugs.


Subject(s)
Acetamides/pharmacology , Antineoplastic Agents/pharmacology , Brain Neoplasms/drug therapy , Drug Discovery/methods , Drug Screening Assays, Antitumor/methods , Glioblastoma/drug therapy , Blood-Brain Barrier , Cell Line, Tumor , Cell Survival/drug effects , Fenofibrate/pharmacology , Humans , Molecular Conformation
15.
Cancers (Basel) ; 11(6)2019 May 31.
Article in English | MEDLINE | ID: mdl-31159203

ABSTRACT

Previous investigations proposed a link between the Epstein-Barr virus (EBV) and lung cancer (LC), but the results are highly controversial largely due to the insufficient sample size and the inherent limitation of the traditional viral screening methods such as PCR. Unlike PCR, current next-generation sequencing (NGS) utilizes an unbiased method for the global assessment of all exogenous agents within a cancer sample with high sensitivity and specificity. In our current study, we aim to resolve this long-standing controversy by utilizing our unbiased NGS-based informatics approaches in conjunction with traditional molecular methods to investigate the role of EBV in a total of 1127 LC. In situ hybridization analysis of 110 LC and 10 normal lung samples detected EBV transcripts in 3 LC samples. Comprehensive virome analyses of RNA sequencing (RNA-seq) data sets from 1017 LC and 110 paired adjacent normal lung specimens revealed EBV transcripts in three lung squamous cell carcinoma and one lung adenocarcinoma samples. In the sample with the highest EBV coverage, transcripts from the BamHI A region accounted for the majority of EBV reads. Expression of EBNA-1, LMP-1 and LMP-2 was observed. A number of viral circular RNA candidates were also detected. Thus, we for the first time revealed a type II latency-like viral transcriptome in the setting of LC in vivo. The high-level expression of viral BamHI A transcripts in LC suggests a functional role of these transcripts, likely as long non-coding RNA. Analyses of cellular gene expression and stained tissue sections indicated an increased immune cell infiltration in the sample expressing high levels of EBV transcripts compared to samples expressing low EBV transcripts. Increased level of immune checkpoint blockade factors was also detected in the sample with higher levels of EBV transcripts, indicating an induced immune tolerance. Lastly, inhibition of immune pathways and activation of oncogenic pathways were detected in the sample with high EBV transcripts compared to the EBV-low LC indicating the direct regulation of cancer pathways by EBV. Taken together, our data support the notion that EBV likely plays a pathological role in a subset of LC.

16.
Am J Pathol ; 188(10): 2339-2355, 2018 10.
Article in English | MEDLINE | ID: mdl-30075149

ABSTRACT

Liver cirrhosis is an independent risk factor for hepatocellular carcinoma (HCC). The mechanisms that contribute to HCC development in the cirrhotic microenvironment are unknown. We found that HCC grown in the highly stressed cirrhotic microenvironment undergoes autophagy switching from a protective state characterized by high macroautophagy with low chaperone-mediated autophagy (CMA) to an HCC-promoting state characterized by low macroautophagy with high CMA. This study examined how the stress response executes oncogenic cell programming through autophagy switching using hepatitis C virus cell culture. Protein kinase R-like endoplasmic reticulum kinase expression increased to high levels in hepatitis C virus culture. Protein kinase R-like endoplasmic reticulum kinase-dependent activation of nuclear factor erythroid 2-related factor (Nrf2) led to increased transcription of the cytoprotective genes: heat shock cognate 70 kDa protein and lysosome-associated membrane protein 2A (LAMP2A) and precipitated the induction of CMA. CMA selectively targeted beclin1 degradation, leading to accumulation of the autophagy flux protein p62 due to impaired autophagosome-endosome fusion. This impaired autophagosome-endosome fusion due to beclin1 degradation inhibited endocytosis and degradation of epidermal growth factor receptor. Silencing Nrf2 and LAMP2A reduced cell viability, suggesting that the stress response activates CMA as a compensatory mechanism of cell survival. We report a novel mechanism through which stress response triggers oncogenic Nrf2 signaling that promotes autophagy switching to favor cell survival.


Subject(s)
Autophagy/physiology , Beclin-1/metabolism , Hepatitis C, Chronic/physiopathology , Cell Survival/physiology , Cells, Cultured , Gene Silencing/physiology , Hepacivirus/physiology , Hepatocytes/physiology , Humans , Lysosomal Membrane Proteins/physiology , Molecular Chaperones/physiology , NF-E2-Related Factor 2/physiology , Neoplasm Proteins/physiology , Signal Transduction/physiology , Stress, Physiological/physiology , Virus Replication/physiology
17.
Mol Cell Biol ; 38(10)2018 05 15.
Article in English | MEDLINE | ID: mdl-29483302

ABSTRACT

Insulin receptor substrate 1 (IRS-1) is a common cytosolic adaptor molecule involved in signal transduction from insulin and insulin-like growth factor I (IGF-I) receptors. IRS-1 can also be found in the nucleus. We report here a new finding of unique IRS-1 nuclear structures, which we observed initially in glioblastoma biopsy specimens and glioblastoma xenografts. These nuclear structures can be reproduced in vitro by the ectopic expression of IRS-1 cDNA cloned in frame with the nuclear localization signal (NLS-IRS-1). In these structures, IRS-1 localizes at the periphery, while the center harbors a key autophagy protein, LC3. These new nuclear structures are highly dynamic, rapidly exchange IRS-1 molecules with the surrounding nucleoplasm, disassemble during mitosis, and require a growth stimulus for their reassembly and maintenance. In tumor cells engineered to express NLS-IRS-1, the IRS-1/LC3 nuclear structures repress autophagy induced by either amino acid starvation or rapamycin treatment. In this process, IRS-1 nuclear structures sequester LC3 inside the nucleus, possibly preventing its cytosolic translocation and the formation of new autophagosomes. This novel mechanism provides a quick and reversible way of inhibiting autophagy, which could counteract autophagy-induced cancer cell death under severe stress, including anticancer therapies.


Subject(s)
Insulin Receptor Substrate Proteins/metabolism , Insulin Receptor Substrate Proteins/physiology , Adaptor Proteins, Signal Transducing , Autophagy/physiology , Cell Nucleus/physiology , Cell Survival/genetics , Glioblastoma/metabolism , HeLa Cells , Humans , Insulin Receptor Substrate Proteins/genetics , Insulin Receptor Substrate Proteins/ultrastructure , Insulin-Like Growth Factor I/physiology , Microtubule-Associated Proteins/physiology , Neoplasms , Phosphoproteins , Receptor, IGF Type 1/physiology , Signal Transduction
18.
Bioorg Med Chem ; 25(19): 5068-5076, 2017 10 01.
Article in English | MEDLINE | ID: mdl-28864149

ABSTRACT

Diazinane and aryl moieties with vinylamine linkers were synthesized to investigate the importance of their structural variations as potential anti-glioblastoma agents. Structural variations incorporated on to the diazinane moiety included oxa and thio derivatives, each with a variety of nitrogen-bound substituents. The size and shape of the aromatic moiety was varied, with the final variation introducing two carbonyl groups, yielding a substituted anthraquinone. Readily available diazinanes and aryl amines were used asan advantageous foundation. Several parameters were calculated whilst engineering these compounds, including: ClogP, molecular polarizability, polar surface area, minimal molecular projected area, and pKa. In addition, a simple and efficient procedure was developed to synthesize these compounds. It was demonstrated that a vinylamine with 1,3-diazinane-2,4,6-trione and 1-anthraquinone moiety is the most promising drug candidate causing almost 70% of LN229 tumor cell death at 1µg/ml. In addition, its molecular polarizability, polar surface area and minimal molecular projected area indicate a possible potential of this molecule for crossing BBB.


Subject(s)
Anthraquinones/chemistry , Anthraquinones/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Barbiturates/chemistry , Barbiturates/pharmacology , Glioblastoma/drug therapy , Amination , Anthraquinones/chemical synthesis , Antineoplastic Agents/chemical synthesis , Barbiturates/chemical synthesis , Cell Death/drug effects , Cell Line, Tumor , Drug Screening Assays, Antitumor , Humans
19.
Sci Rep ; 7(1): 9223, 2017 08 23.
Article in English | MEDLINE | ID: mdl-28835697

ABSTRACT

The mechanism of how chronic hepatitis C virus (HCV) infection leads to such a high rate of hepatocellular carcinoma (HCC) is unknown. We found that the PERK axis of endoplasmic reticulum (ER) stress elicited prominent nuclear translocation of Nrf2 in 100% of HCV infected hepatocytes. The sustained nuclear translocation of Nrf2 in chronically infected culture induces Mdm2-mediated retinoblastoma protein (Rb) degradation. Silencing PERK and Nrf2 restored Mdm2-mediated Rb degradation, suggesting that sustained activation of PERK/Nrf2 axis creates oncogenic stress in chronically infected HCV culture model. The activation of Nrf2 and its nuclear translocation were prevented by ER-stress and PERK inhibitors, suggesting that PERK axis is involved in the sustained activation of Nrf2 signaling during chronic HCV infection. Furthermore, we show that HCV clearance induced by interferon-α based antiviral normalized the ER-stress response and prevented nuclear translocation of Nrf2, whereas HCV clearance by DAAs combination does neither. In conclusion, we report here a novel mechanism for how sustained activation of PERK axis of ER-stress during chronic HCV infection activates oncogenic Nrf2 signaling that promotes hepatocyte survival and oncogenesis by inducing Mdm2-mediated Rb degradation.


Subject(s)
Hepatitis C, Chronic/metabolism , Hepatitis C, Chronic/virology , NF-E2-Related Factor 2/metabolism , Proto-Oncogene Proteins c-mdm2/metabolism , Retinoblastoma Protein/metabolism , Signal Transduction , eIF-2 Kinase/metabolism , Active Transport, Cell Nucleus , Cell Line , Cells, Cultured , Endoplasmic Reticulum Stress , Gene Silencing , Genomic Instability , Hepatitis C, Chronic/pathology , Hepatocytes/metabolism , Hepatocytes/virology , Humans , Immunohistochemistry , Proteolysis , Reactive Oxygen Species/metabolism , Virus Replication
20.
J Cell Physiol ; 232(6): 1275-1286, 2017 Jun.
Article in English | MEDLINE | ID: mdl-27607558

ABSTRACT

Ethanol plays a detrimental role in the development of the brain. Multiple studies have shown that ethanol inhibits insulin-like growth factor I receptor (IGF-IR) function. Because the IGF-IR contributes to brain development by supporting neural growth, survival, and differentiation, we sought to determine the molecular mechanism(s) involved in ethanol's effects on this membrane-associated tyrosine kinase. Using multiple neuronal cell types, we performed Western blot, immunoprecipitation, and GST-pulldowns following acute (1-24 h) or chronic (3 weeks) treatment with ethanol. Surprisingly, exposure of multiple neuronal cell types to acute (up to 24 h) ethanol (50 mM) enhanced IGF-I-induced phosphorylation of extracellular regulated kinases (ERKs), without affecting IGF-IR tyrosine phosphorylation itself, or Akt phosphorylation. This acute increase in ERKs phosphorylation was followed by the expected inhibition of the IGF-IR signaling following 3-week ethanol exposure. We then expressed a GFP-tagged IGF-IR construct in PC12 cells and used them to perform fluorescence recovery after photobleaching (FRAP) analysis. Using these fluorescently labeled cells, we determined that 50 mM ethanol decreased the half-time of the IGF-IR-associated FRAP, which implied that cell membrane-associated signaling events could be affected. Indeed, co-immunoprecipitation and GST-pulldown studies demonstrated that the acute ethanol exposure increased the recruitment of p52-Shc to the Grb2-Shc complex, which is known to engage the Ras-Raf-ERKs pathway following IGF-1 stimulation. These experiments indicate that even a short and low-dose exposure to ethanol may dysregulate function of the receptor, which plays a critical role in brain development. J. Cell. Physiol. 232: 1275-1286, 2017. © 2016 Wiley Periodicals, Inc.


Subject(s)
Ethanol/pharmacology , Extracellular Signal-Regulated MAP Kinases/metabolism , GRB2 Adaptor Protein/metabolism , Insulin-Like Growth Factor I/pharmacology , Src Homology 2 Domain-Containing, Transforming Protein 1/metabolism , Animals , Cell Membrane/drug effects , Cell Membrane/metabolism , Humans , Insulin Receptor Substrate Proteins/metabolism , Mice , PC12 Cells , Phosphorylation/drug effects , Rats , Receptor, IGF Type 1/metabolism , Signal Transduction/drug effects , Time Factors
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