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Huang L, Liu J, Zhang XO, Sibley K, Najjar SM, Lee MM, Wu Q. Inhibition of protein arginine methyltransferase 5 enhances hepatic mitochondrial biogenesis. J Biol Chem 2018; 293:10884-10894. [PMID: 29773653 DOI: 10.1074/jbc.ra118.002377] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/01/2018] [Indexed: 11/06/2022] Open
Abstract
Protein arginine methyltransferase 5 (PRMT5) regulates gene expression either transcriptionally by symmetric dimethylation of arginine residues on histones H4R3, H3R8, and H2AR3 or at the posttranslational level by methylation of nonhistone target proteins. Although emerging evidence suggests that PRMT5 functions as an oncogene, its role in metabolic diseases is not well-defined. We investigated the role of PRMT5 in promoting high-fat-induced hepatic steatosis. A high-fat diet up-regulated PRMT5 levels in the liver but not in other metabolically relevant tissues such as skeletal muscle or white and brown adipose tissue. This was associated with repression of master transcription regulators involved in mitochondrial biogenesis. In contrast, lentiviral short hairpin RNA-mediated reduction of PRMT5 significantly decreased phosphatidylinositol 3-kinase/AKT signaling in mouse AML12 liver cells. PRMT5 knockdown or knockout decreased basal AKT phosphorylation but boosted the expression of peroxisome proliferator-activated receptor α (PPARα) and PGC-1α with a concomitant increase in mitochondrial biogenesis. Moreover, by overexpressing an exogenous WT or enzyme-dead mutant PRMT5 or by inhibiting PRMT5 enzymatic activity with a small-molecule inhibitor, we demonstrated that the enzymatic activity of PRMT5 is required for regulation of PPARα and PGC-1α expression and mitochondrial biogenesis. Our results suggest that targeting PRMT5 may have therapeutic potential for the treatment of fatty liver.
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Affiliation(s)
- Lei Huang
- From the Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts 01655
| | - Jehnan Liu
- the Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio 43606
| | - Xiao-Ou Zhang
- the Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01655
| | - Katelyn Sibley
- the Department of Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, and
| | - Sonia M Najjar
- the Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio 43606.,the Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio 45701
| | - Mary M Lee
- From the Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts 01655,
| | - Qiong Wu
- From the Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts 01655,
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202
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Chen QY, Costa M. PI3K/Akt/mTOR Signaling Pathway and the Biphasic Effect of Arsenic in Carcinogenesis. Mol Pharmacol 2018; 94:784-792. [PMID: 29769245 PMCID: PMC5994485 DOI: 10.1124/mol.118.112268] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 04/30/2018] [Indexed: 12/22/2022] Open
Abstract
Arsenic is a naturally occurring, ubiquitous metalloid found in the Earth’s crust. In its inorganic form, arsenic is highly toxic and carcinogenic and is widely found across the globe and throughout the environment. As an International Agency for Research on Cancer–defined class 1 human carcinogen, arsenic can cause multiple human cancers, including liver, lung, urinary bladder, skin, kidney, and prostate. Mechanisms of arsenic-induced carcinogenesis remain elusive, and this review focuses specifically on the role of the PI3K/AKT/mTOR pathway in promoting cancer development. In addition to exerting potent carcinogenic responses, arsenic is also known for its therapeutic effects against acute promyelocytic leukemia. Current literature suggests that arsenic can achieve both therapeutic as well as carcinogenic effects, and this review serves to examine the paradoxical effects of arsenic, specifically through the PI3K/AKT/mTOR pathway. Furthermore, a comprehensive review of current literature reveals an imperative need for future studies to establish and pinpoint the exact conditions for which arsenic can, and through what mechanisms it is able to, differentially regulate the PI3K/AKT/mTOR pathway to maximize the therapeutic and minimize the carcinogenic properties of arsenic.
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Affiliation(s)
- Qiao Yi Chen
- Department of Environmental Medicine, New York University School of Medicine, Tuxedo, New York
| | - Max Costa
- Department of Environmental Medicine, New York University School of Medicine, Tuxedo, New York
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203
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Multiscale systems pharmacological analysis of everolimus action in hepatocellular carcinoma. J Pharmacokinet Pharmacodyn 2018; 45:607-620. [PMID: 29725796 DOI: 10.1007/s10928-018-9590-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Accepted: 04/23/2018] [Indexed: 12/13/2022]
Abstract
Dysregulation of mTOR pathway is common in hepatocellular carcinoma (HCC). A translational quantitative systems pharmacology (QSP), pharmacokinetic (PK), and pharmacodynamic (PD) model dissecting the circuitry of this pathway was developed to predict HCC patients' response to everolimus, an mTOR inhibitor. The time course of key signaling proteins in the mTOR pathway, HCC cells viability, tumor volume (TV) and everolimus plasma and tumor concentrations in xenograft mice, clinical PK of everolimus and progression free survival (PFS) in placebo and everolimus-treated patients were extracted from literature. A comprehensive and multiscale QSP/PK/PD model was developed, qualified, and translated to clinical settings. Model fittings and simulations were performed using Monolix software. The S6-kinase protein was identified as critical in the mTOR signaling pathway for describing everolimus lack of efficacy in HCC patients. The net growth rate constant (kg) of HCC cells was estimated at 0.02 h-1 (2.88%RSE). The partition coefficient of everolimus into the tumor (kp) was determined at 0.06 (12.98%RSE). The kg in patients was calculated from the doubling time of TV in naturally progressing HCC patients, and was determined at 0.004 day-1. Model-predicted and observed PFS were in good agreement for placebo and everolimus-treated patients. In conclusion, a multiscale QSP/PK/PD model elucidating everolimus lack of efficacy in HCC patients was successfully developed and predicted PFS reasonably well compared to observed clinical findings. This model may provide insights into clinical response to everolimus-based therapy and serve as a valuable tool for the clinical translation of efficacy for novel mTOR inhibitors.
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204
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L-Arginine Enhances Protein Synthesis by Phosphorylating mTOR (Thr 2446) in a Nitric Oxide-Dependent Manner in C2C12 Cells. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:7569127. [PMID: 29854093 PMCID: PMC5944195 DOI: 10.1155/2018/7569127] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 02/24/2018] [Accepted: 03/22/2018] [Indexed: 12/16/2022]
Abstract
Muscle atrophy may arise from many factors such as inactivity, malnutrition, and inflammation. In the present study, we investigated the stimulatory effect of nitric oxide (NO) on muscle protein synthesis. Primarily, C2C12 cells were supplied with extra L-arginine (L-Arg) in the culture media. L-Arg supplementation increased the activity of inducible nitric oxide synthase (iNOS), the rate of protein synthesis, and the phosphorylation of mTOR (Thr 2446) and p70S6K (Thr 389). L-NAME, an NOS inhibitor, decreased NO concentrations within cells and abolished the stimulatory effect of L-Arg on protein synthesis and the phosphorylation of mTOR and p70S6K. In contrast, SNP (sodium nitroprusside), an NO donor, increased NO concentrations, enhanced protein synthesis, and upregulated mTOR and p70S6K phosphorylation, regardless of L-NAME treatment. Blocking mTOR with rapamycin abolished the stimulatory effect of both L-Arg and SNP on protein synthesis and p70S6K phosphorylation. These results indicate that L-Arg stimulates protein synthesis via the activation of the mTOR (Thr 2446)/p70S6K signaling pathway in an NO-dependent manner.
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205
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Xue W, Wang M, Zhang L, Gu J, Zhu X, Wang Y, Wang R, Wang L, Wang W, Wang XF, Mei JW, Zheng L, Zhu ML. Genetic Variants Within MTORC1 Genes Predict Gastric Cancer Prognosis in Chinese Populations. J Cancer 2018; 9:1448-1454. [PMID: 29721055 PMCID: PMC5929090 DOI: 10.7150/jca.23566] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 01/27/2018] [Indexed: 01/29/2023] Open
Abstract
Objective: Mammalian target of rapamycin complex 1 (mTORC1) plays an important role in maintaining proper cellular functions in gastric cancer (GC). Previous studies demonstrated genetic variants within mTORC1 genes were associated with GC risk. However, no studies reported the associations between genetic variants within mTORC1 genes and GC prognosis. Herein, we firstly assessed the associations of genetic variants of mTORC1 genes with overall survival (OS) of GC in Chinese populations. Methods: We genotyped eight single nucleotide polymorphisms (SNPs) in mTORC1 genes (i.e., rs2536 T>C and rs1883965 G>A for mTOR, rs3160 T>C and rs26865 A>G for MLST8, rs3751934 C>A, rs1062935 T>C, rs3751932 T>C and rs12602885 G>A for RPTOR) by the TaqMan method in 197 Chinese GC patients who had surgical resection in Xinhua Hospital. We conducted Kaplan-Meier survival plots and Cox hazards regression analysis to explore the associations of these SNPs with OS. Results: The single-locus analysis indicated that RPTOR rs1062935 T>C was associated with an increased risk of poor GC prognosis (CC vs. TT/TC: adjusted Hazard ratio (HR) = 1.71, 95% confidence interval (CI) = 1.04-2.82). The combined analysis of all eight SNPs showed that patients with more than three risk genotypes significantly increased risk of death (adjusted HR = 2.44, 95% CI = 1.30-4.58), when compared to those with three or less risk genotypes. Conclusions: Our findings indicated that genetic variants within mTORC1 genes may predict GC prognosis in Chinese populations. The results need to be validated in future studies with larger sample sizes.
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Affiliation(s)
- Wenji Xue
- Department of Oncology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200092, China.,Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Mengyun Wang
- Cancer Institute, Collaborative Innovation Center for Cancer Medicine, Fudan University Shanghai Cancer Center, Shanghai, 200032, China
| | - Li Zhang
- Department of Oncology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200092, China
| | - Jianchun Gu
- Department of Oncology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200092, China
| | - Xueru Zhu
- Department of Oncology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200092, China
| | - Yiwei Wang
- Department of Oncology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200092, China
| | - Ruifen Wang
- Department of Pathology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200092, China
| | - Lifeng Wang
- Department of Pathology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200092, China
| | - Weiye Wang
- MOE-Shanghai Key Lab of Children's Environmental Health, Xinhua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Xue-Feng Wang
- Department of General Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200092, China.,Institute of Biliary Tract Disease, Xinhua Hospital, School of Medicine, Shanghai JiaoTong University, Shanghai, 200092, China
| | - Jia-Wei Mei
- Department of General Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200092, China.,Institute of Biliary Tract Disease, Xinhua Hospital, School of Medicine, Shanghai JiaoTong University, Shanghai, 200092, China
| | - Leizhen Zheng
- Department of Oncology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200092, China
| | - Mei-Ling Zhu
- Department of Oncology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200092, China
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206
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Trentin L, Queudeville M, Eckhoff SM, Hasan N, Münch V, Boldrin E, Seyfried F, Enzenmüller S, Debatin KM, Meyer LH. Leukemia reconstitution in vivo is driven by cells in early cell cycle and low metabolic state. Haematologica 2018. [PMID: 29519870 PMCID: PMC6058781 DOI: 10.3324/haematol.2017.167502] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
In contrast to well-established hierarchical concepts of tumor stem cells, leukemia-initiating cells in B-cell precursor acute lymphoblastic leukemia have not yet been phenotypically identified. Different subpopulations, as defined by surface markers, have shown equal abilities to reconstitute leukemia upon transplantation into immunodeficient mice. Using a non-obese diabetes/severe combined immunodeficiency human acute lymphoblastic leukemia mouse model and cell cycle analysis annotating cells to distinct cycle phases, we functionally characterized leukemia-initiating cells and found that cells in all stages of the cell cycle are able to reconstitute leukemia in vivo, with early cycling cells (G1blow population) exhibiting the highest leukemia-initiating potential. Interestingly, cells of the G2/M compartment, i.e. dividing cells, were less effective in leukemia reconstitution. Moreover, G1blow cells were more resistant to spontaneous or drug-induced cell death in vitro, were enriched for stem cell signatures and were less metabolically active, as determined by lower levels of reactive oxygen species, compared to G2/M stage cells. Our data provide new information on the biological properties of leukemia-initiating cells in B-cell precursor acute lymphoblastic leukemia and underline the concept of a stochastic model of leukemogenesis.
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Affiliation(s)
- Luca Trentin
- Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Germany
| | - Manon Queudeville
- Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Germany
| | - Sarah Mirjam Eckhoff
- Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Germany
| | - Nabiul Hasan
- Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Germany
| | - Vera Münch
- Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Germany.,International Graduate School in Molecular Medicine, Ulm University, Germany
| | - Elena Boldrin
- Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Germany.,International Graduate School in Molecular Medicine, Ulm University, Germany
| | - Felix Seyfried
- Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Germany
| | - Stefanie Enzenmüller
- Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Germany
| | - Klaus-Michael Debatin
- Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Germany
| | - Lüder Hinrich Meyer
- Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Germany
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207
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Rodenak-Kladniew B, Castro A, Stärkel P, De Saeger C, García de Bravo M, Crespo R. Linalool induces cell cycle arrest and apoptosis in HepG2 cells through oxidative stress generation and modulation of Ras/MAPK and Akt/mTOR pathways. Life Sci 2018; 199:48-59. [PMID: 29510199 DOI: 10.1016/j.lfs.2018.03.006] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 02/20/2018] [Accepted: 03/02/2018] [Indexed: 12/11/2022]
Abstract
AIMS Linalool is a plant-derived monoterpene with anticancer activity, however its mechanisms of action remain poorly understood. The aim of this work was to elucidate the anticancer mechanisms of action of linalool in hepatocellular carcinoma (HCC) HepG2 cells. MAIN METHODS Cell viability and proliferation were determined by WST-1 assay and BrdU incorporation, respectively. Cell cycle analysis was assessed through flow cytometry (FC) and western blot (WB). Apoptosis was determined by caspase-3 activity, TUNEL assay and WB. Reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were analyzed by FC and fluorescence microscopy. Expression of Ras, MAPKs (ERK, JNK and p38) and Akt/mTOR pathways were evaluated by WB. KEY FINDINGS Linalool (0-2.5 mM) dose-dependently inhibited cell proliferation by inducing G0/G1 cell cycle arrest, through Cdk4 and cyclin A downregulation, p21 and p27 upregulation, and apoptosis, characterized by MMP loss, caspase-3 activation, PARP cleavage and DNA fragmentation. Low concentrations of linalool (1.0 mM) reduced membrane-bound Ras and Akt activity whereas higher amounts (2.0 mM) triggered mTOR inhibition and ROS generation, in correlation with MAPKs activation and Akt phosphorylation. ROS scavenger N-acetyl-L-cysteine partially rescued HepG2 cell growth and prevented MPP depolarization, ERK and JNK activation. Moreover, specific ERK and Akt phosphorylation inhibitors potentiated linalool anti-cancer activity, pointing Akt and ERK activation as pro-survival mechanisms in response to higher concentrations of linalool. SIGNIFICANCE This report reveals that linalool induces G0/G1 arrest and apoptosis in HepG2 cells involving Ras, MAPKs and Akt/mTOR pathways and suggests that linalool is a promising anticancer agent for HCC therapy.
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Affiliation(s)
- Boris Rodenak-Kladniew
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CONICET-UNLP, CCT-La Plata, Facultad de Ciencias Médicas, La Plata, Argentina
| | - Agustina Castro
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CONICET-UNLP, CCT-La Plata, Facultad de Ciencias Médicas, La Plata, Argentina
| | - Peter Stärkel
- Laboratory of Gastroenterology, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium; Department of Gastroenterology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Christine De Saeger
- Laboratory of Gastroenterology, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
| | - Margarita García de Bravo
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CONICET-UNLP, CCT-La Plata, Facultad de Ciencias Médicas, La Plata, Argentina
| | - Rosana Crespo
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CONICET-UNLP, CCT-La Plata, Facultad de Ciencias Médicas, La Plata, Argentina.
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208
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SESN2 negatively regulates cell proliferation and casein synthesis by inhibition the amino acid-mediated mTORC1 pathway in cow mammary epithelial cells. Sci Rep 2018; 8:3912. [PMID: 29500367 PMCID: PMC5834632 DOI: 10.1038/s41598-018-22208-w] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 02/09/2018] [Indexed: 01/01/2023] Open
Abstract
Amino acids (AA) are one of the key nutrients that regulate cell proliferation and casein synthesis in cow mammary epithelial cells (CMEC), but the mechanism of this regulation is not yet clear. In this study, the effect of SESN2 on AA-mediated cell proliferation and casein synthesis in CMEC was assessed. After 12 h of AA starvation, CMECs were cultured in the absence of all AA (AA-), in the presences of only essential AA (EAA+), or of all AA (AA+). Cell proliferation, casein expression, and activation of the mammalian target of rapamycin complex 1 (mTORC1) pathway were increased; but SESN2 expression was decreased in response to increased EAA or AA supply. Overexpressing or inhibiting SESN2 demonstrated that cell proliferation, casein expression, and activation of the mTORC1 pathway were all controlled by SESN2 expression. Furthermore, the increase in cell proliferation, casein expression, and activation of the mTORC1 pathway in response to AA supply was inhibited by overexpressing SESN2, and those effects were reversed by inhibiting SESN2. These results indicate that SESN2 is an important inhibitor of mTORC1 in CMEC blocking AA-mediated cell proliferation and casein synthesis.
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209
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Djuzenova CS, Fiedler V, Katzer A, Michel K, Deckert S, Zimmermann H, Sukhorukov VL, Flentje M. Dual PI3K- and mTOR-inhibitor PI-103 can either enhance or reduce the radiosensitizing effect of the Hsp90 inhibitor NVP-AUY922 in tumor cells: The role of drug-irradiation schedule. Oncotarget 2018; 7:38191-38209. [PMID: 27224913 PMCID: PMC5122382 DOI: 10.18632/oncotarget.9501] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 05/01/2016] [Indexed: 12/12/2022] Open
Abstract
Inhibition of Hsp90 can increase the radiosensitivity of tumor cells. However, inhibition of Hsp90 alone induces the anti-apoptotic Hsp70 and thereby decreases radiosensitivity. Therefore, preventing Hsp70 induction can be a promising strategy for radiosensitization. PI-103, an inhibitor of PI3K and mTOR, has previously been shown to suppress the up-regulation of Hsp70. Here, we explore the impact of combining PI-103 with the Hsp90 inhibitor NVP-AUY922 in irradiated glioblastoma and colon carcinoma cells. We analyzed the cellular response to drug-irradiation treatments by colony-forming assay, expression of several marker proteins, cell cycle progression and induction/repair of DNA damage. Although PI-103, given 24 h prior to irradiation, slightly suppressed the NVP-AUY922-mediated up-regulation of Hsp70, it did not cause radiosensitization and even diminished the radiosensitizing effect of NVP-AUY922. This result can be explained by the activation of PI3K and ERK pathways along with G1-arrest at the time of irradiation. In sharp contrast, PI-103 not only exerted a radiosensitizing effect but also strongly enhanced the radiosensitization by NVP-AUY922 when both inhibitors were added 3 h before irradiation and kept in culture for 24 h. Possible reasons for the observed radiosensitization under this drug-irradiation schedule may be a down-regulation of PI3K and ERK pathways during or directly after irradiation, increased residual DNA damage and strong G2/M arrest 24 h thereafter. We conclude that duration of drug treatment before irradiation plays a key role in the concomitant targeting of PI3K/mTOR and Hsp90 in tumor cells.
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Affiliation(s)
- Cholpon S Djuzenova
- Department of Radiation Oncology, University Hospital of Würzburg, Würzburg, Germany
| | - Vanessa Fiedler
- Department of Radiation Oncology, University Hospital of Würzburg, Würzburg, Germany
| | - Astrid Katzer
- Department of Radiation Oncology, University Hospital of Würzburg, Würzburg, Germany
| | - Konstanze Michel
- Department of Radiation Oncology, University Hospital of Würzburg, Würzburg, Germany
| | - Stefanie Deckert
- Department of Radiation Oncology, University Hospital of Würzburg, Würzburg, Germany
| | - Heiko Zimmermann
- Fraunhofer-Institut für Biomedizinische Technik, St. Ingbert and Lehrstuhl für Molekulare und Zelluläre Biotechnologie/Nanotechnologie, Universität des Saarlandes, Saarbrücken, Germany
| | - Vladimir L Sukhorukov
- Department of Biotechnology and Biophysics, University of Würzburg, Würzburg, Germany
| | - Michael Flentje
- Department of Radiation Oncology, University Hospital of Würzburg, Würzburg, Germany.,Comprehensive Cancer Center Mainfranken, University of Würzburg, Würzburg, Germany
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210
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Redaelli S, Ceccon M, Antolini L, Rigolio R, Pirola A, Peronaci M, Gambacorti-Passerini C, Mologni L. Synergistic activity of ALK and mTOR inhibitors for the treatment of NPM-ALK positive lymphoma. Oncotarget 2018; 7:72886-72897. [PMID: 27662658 PMCID: PMC5341951 DOI: 10.18632/oncotarget.12128] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 09/13/2016] [Indexed: 12/31/2022] Open
Abstract
ALK-positive Anaplastic Large Cell Lymphoma (ALCL) represents a subset of Non-Hodgkin Lymphoma whose treatment benefited from crizotinib development, a dual ALK/MET inhibitor. Crizotinib blocks ALK-triggered pathways such as PI3K/AKT/mTOR, indispensable for survival of ALK-driven tumors. Despite the positive impact of targeted treatment in ALCL, resistant clones are often selected during therapy. Strategies to overcome resistance include the design of second generation drugs and the use of combined therapies that simultaneously target multiple nodes essential for cells survival. We investigated the effects of combined ALK/mTOR inhibition. We observed a specific synergistic effect of combining ALK inhibitors with an mTOR inhibitor (temsirolimus), in ALK+ lymphoma cells. The positive cooperation resulted in an increased inhibition of mTOR effectors, compared to single treatments, a block in G0/G1 phase and induction of apoptosis. The combination was able to prevent the selection of resistant clones, while long-term exposure to single agents led to the establishment of resistant cell lines, with either ALK inhibitor or temsirolimus. In vivo, mice injected with Karpas 299 cells and treated with low dose combination showed complete regression of tumors, while only partial inhibition was obtained in single agents-treated mice. Upon treatment stop the combination was able to significantly delay tumor relapses. Re-challenge of relapsed tumors at a higher dose led to full regression of xenografts in the combination group, but not in mice treated with lorlatinib alone. In conclusion, our data suggest that the combination of ALK and mTOR inhibitors could be a valuable therapeutic option for ALK+ ALCL patients.
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Affiliation(s)
- Sara Redaelli
- University of Milano Bicocca, School of Medicine, 20900 Monza, Italy
| | - Monica Ceccon
- University of Milano Bicocca, School of Medicine, 20900 Monza, Italy
| | - Laura Antolini
- Center of Biostatistics for Clinical Epidemiology, University of Milano Bicocca, School of Medicine, 20900 Monza, Italy
| | - Roberta Rigolio
- University of Milano Bicocca, School of Medicine, 20900 Monza, Italy
| | - Alessandra Pirola
- University of Milano Bicocca, School of Medicine, 20900 Monza, Italy
| | - Marco Peronaci
- University of Milano Bicocca, School of Medicine, 20900 Monza, Italy
| | - Carlo Gambacorti-Passerini
- University of Milano Bicocca, School of Medicine, 20900 Monza, Italy.,San Gerardo Hospital, Hematology-Clinical Research Unit, 20900 Monza, Italy
| | - Luca Mologni
- University of Milano Bicocca, School of Medicine, 20900 Monza, Italy
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211
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Shen Y, Sherman JW, Chen X, Wang R. Phosphorylation of CDC25C by AMP-activated protein kinase mediates a metabolic checkpoint during cell-cycle G 2/M-phase transition. J Biol Chem 2018; 293:5185-5199. [PMID: 29467227 PMCID: PMC5892595 DOI: 10.1074/jbc.ra117.001379] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 02/01/2018] [Indexed: 12/30/2022] Open
Abstract
From unicellular to multicellular organisms, cell-cycle progression is tightly coupled to biosynthetic and bioenergetic demands. Accumulating evidence has demonstrated the G1/S-phase transition as a key checkpoint where cells respond to their metabolic status and commit to replicating the genome. However, the mechanism underlying the coordination of metabolism and the G2/M-phase transition in mammalian cells remains unclear. Here, we show that the activation of AMP-activated protein kinase (AMPK), a highly conserved cellular energy sensor, significantly delays mitosis entry. The cell-cycle G2/M-phase transition is controlled by mitotic cyclin-dependent kinase complex (CDC2-cyclin B), which is inactivated by WEE1 family protein kinases and activated by the opposing phosphatase CDC25C. AMPK directly phosphorylates CDC25C on serine 216, a well-conserved inhibitory phosphorylation event, which has been shown to mediate DNA damage–induced G2-phase arrest. The acute induction of CDC25C or suppression of WEE1 partially restores mitosis entry in the context of AMPK activation. These findings suggest that AMPK-dependent phosphorylation of CDC25C orchestrates a metabolic checkpoint for the cell-cycle G2/M-phase transition.
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Affiliation(s)
- Yuqing Shen
- From the Center for Childhood Cancer and Blood Diseases, Hematology/Oncology and BMT, Research Institute at Nationwide Children's Hospital, Ohio State University, Columbus, Ohio 43205 and.,the Department of Microbiology and Immunology, Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, Medical School, Southeast University, Nanjing 210009, China
| | - John William Sherman
- From the Center for Childhood Cancer and Blood Diseases, Hematology/Oncology and BMT, Research Institute at Nationwide Children's Hospital, Ohio State University, Columbus, Ohio 43205 and
| | - Xuyong Chen
- From the Center for Childhood Cancer and Blood Diseases, Hematology/Oncology and BMT, Research Institute at Nationwide Children's Hospital, Ohio State University, Columbus, Ohio 43205 and
| | - Ruoning Wang
- From the Center for Childhood Cancer and Blood Diseases, Hematology/Oncology and BMT, Research Institute at Nationwide Children's Hospital, Ohio State University, Columbus, Ohio 43205 and
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212
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Pai GM, Zielinski A, Koalick D, Ludwig K, Wang ZQ, Borgmann K, Pospiech H, Rubio I. TSC loss distorts DNA replication programme and sensitises cells to genotoxic stress. Oncotarget 2018; 7:85365-85380. [PMID: 27863419 PMCID: PMC5356742 DOI: 10.18632/oncotarget.13378] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 10/26/2016] [Indexed: 01/14/2023] Open
Abstract
Tuberous Sclerosis (TSC) is characterized by exorbitant mTORC1 signalling and manifests as non-malignant, apoptosis-prone neoplasia. Previous reports have shown that TSC-/- cells are highly susceptible to mild, innocuous doses of genotoxic stress, which drive TSC-/- cells into apoptotic death. It has been argued that this hypersensitivity to stress derives from a metabolic/energetic shortfall in TSC-/- cells, but how metabolic dysregulation affects the DNA damage response and cell cycle alterations in TSC-/- cells exposed to genotoxic stress is not understood. We report here the occurrence of futile checkpoint responses and an unusual type of replicative stress (RS) in TSC1-/- fibroblasts exposed to low-dose genotoxins. This RS is characterized by elevated nucleotide incorporation rates despite only modest origin over-firing. Strikingly, an increased propensity for asymmetric fork progression and profuse chromosomal aberrations upon mild DNA damage confirmed that TSC loss indeed proved detrimental to stress adaptation. We conclude that low stress tolerance of TSC-/- cells manifests at the level of DNA replication control, imposing strong negative selection on genomic instability that could in turn detain TSC-mutant tumours benign.
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Affiliation(s)
- Govind M Pai
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine, University Hospital, 07745 Jena, Germany
| | - Alexandra Zielinski
- Laboratory of Radiobiology & Experimental Radiooncology, Department of Radiotherapy and Radiooncology, Center of Oncology, University Medical Center Hamburg-Eppendorf, Germany, 20246 Hamburg, Germany
| | - Dennis Koalick
- Leibniz Institute on Aging - Fritz Lipmann Institute, 07745 Jena, Germany
| | - Kristin Ludwig
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine, University Hospital, 07745 Jena, Germany
| | - Zhao-Qi Wang
- Leibniz Institute on Aging - Fritz Lipmann Institute, 07745 Jena, Germany
| | - Kerstin Borgmann
- Laboratory of Radiobiology & Experimental Radiooncology, Department of Radiotherapy and Radiooncology, Center of Oncology, University Medical Center Hamburg-Eppendorf, Germany, 20246 Hamburg, Germany
| | - Helmut Pospiech
- Leibniz Institute on Aging - Fritz Lipmann Institute, 07745 Jena, Germany.,Faculty of Biochemistry and Molecular Medicine, University of Oulu, 90014 Oulu, Finland
| | - Ignacio Rubio
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine, University Hospital, 07745 Jena, Germany
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213
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Ye H, Zhang X, Chen Y, Liu Q, Wei J. Ranking novel cancer driving synthetic lethal gene pairs using TCGA data. Oncotarget 2018; 7:55352-55367. [PMID: 27438146 PMCID: PMC5342422 DOI: 10.18632/oncotarget.10536] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 06/30/2016] [Indexed: 12/16/2022] Open
Abstract
Synthetic lethality (SL) has emerged as a promising approach to cancer therapy. In contrast to the costly and labour-intensive genome-wide siRNA or CRISPR-based human cell line screening approaches, computational approaches to prioritize potential synthetic lethality pairs for further experimental validation represent an attractive alternative. In this study, we propose an efficient and comprehensive in-silico pipeline to rank novel SL gene pairs by mining vast amounts of accumulated tumor high-throughput sequencing data in The Cancer Genome Atlas (TCGA), coupled with other protein interaction networks and cell line information. Our pipeline integrates three significant features, including mutation coverage in TCGA, driver mutation probability and the quantified cancer network information centrality, into a ranking model for SL gene pair identification, which is presented as the first learning-based method for SL identification. As a result, 107 potential SL gene pairs were obtained from the top 10 results covering 11 cancers. Functional analysis of these genes indicated that several promising pathways were identified, including the DNA repair related Fanconi Anemia pathway and HIF-1 signaling pathway. In addition, 4 SL pairs, mTOR-TP53, VEGFR2-TP53, EGFR-TP53, ATM-PRKCA, were validated using drug sensitivity information in the cancer cell line databases CCLE or NCI60. Interestingly, significant differences in the cell growth of mTOR siRNA or EGFR siRNA knock-down were detected between cancer cells with wild type TP53 and mutant TP53. Our study indicates that the pre-screening of potential SL gene pairs based on the large genomics data repertoire of tumor tissues and cancer cell lines could substantially expedite the identification of synthetic lethal gene pairs for cancer therapy.
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Affiliation(s)
- Hao Ye
- R&D Information, AstraZeneca, Shanghai, China
| | | | - Yunqin Chen
- R&D Information, AstraZeneca, Shanghai, China
| | - Qi Liu
- Department of Central Laboratory, Shanghai Tenth People's Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Jia Wei
- R&D Information, AstraZeneca, Shanghai, China
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214
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Dan VM, Muralikrishnan B, Sanawar R, J S V, Burkul BB, Srinivas KP, Lekshmi A, Pradeep NS, Dastager SG, Santhakumari B, Santhoshkumar TR, Kumar RA, Pillai MR. Streptomyces sp metabolite(s) promotes Bax mediated intrinsic apoptosis and autophagy involving inhibition of mTOR pathway in cervical cancer cell lines. Sci Rep 2018; 8:2810. [PMID: 29434241 PMCID: PMC5809390 DOI: 10.1038/s41598-018-21249-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 01/26/2018] [Indexed: 02/06/2023] Open
Abstract
In cervical cancer, the association between HPV infection and dysregulation of phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway (PI3K/AKT/mTOR pathway) places mTOR as an attractive therapeutic target. The failure of current treatment modalities in advanced stages of this cancer and drawbacks of already available mTOR inhibitors demand for novel drug candidates. In the present study we identified the presence of a mTOR inhibitor in an active fraction of the ethyl acetate extract of Streptomyces sp OA293. The metabolites(s) in the active fraction completely inhibited mTORC1 and thereby suppressed activation of both of its downstream targets, 4E-BP1 and P70S6k, in cervical cancer cells. In addition, it also stalled Akt activation via inhibition of mTORC2. The mechanism of mTOR inhibition detailed in our study overcomes significant drawbacks of well known mTOR inhibitors such as rapamycin and rapalogs. The active fraction induced autophagy and Bax mediated apoptosis suggesting that mTOR inhibition resulted in programmed cell death of cancer cells. The molecular weight determination of the components in active fraction confirmed the absence of any previously known natural mTOR inhibitor. This is the first report of complete mTOR complex inhibition by a product derived from microbial source.
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Affiliation(s)
- Vipin Mohan Dan
- Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud Post, Poojappura, Thiruvananthapuram, Kerala, India.,Jawaharlal Nehru Tropical Botanical Garden and Research Institute, Palode, Thiruvananthapuram, Kerala, India
| | - Balaji Muralikrishnan
- Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud Post, Poojappura, Thiruvananthapuram, Kerala, India
| | - Rahul Sanawar
- Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud Post, Poojappura, Thiruvananthapuram, Kerala, India
| | - Vinodh J S
- Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud Post, Poojappura, Thiruvananthapuram, Kerala, India.,NCIM Resource centre, Division of Biochemical Sciences, CSIR - National Chemical Laboratory, Pune, Maharashtra, India
| | | | | | - Asha Lekshmi
- Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud Post, Poojappura, Thiruvananthapuram, Kerala, India
| | - N S Pradeep
- Jawaharlal Nehru Tropical Botanical Garden and Research Institute, Palode, Thiruvananthapuram, Kerala, India
| | - Syed G Dastager
- NCIM Resource centre, Division of Biochemical Sciences, CSIR - National Chemical Laboratory, Pune, Maharashtra, India
| | - B Santhakumari
- Proteomics facility, CSIR - National Chemical Laboratory, Pune, Maharashtra, India
| | - Thankayyan R Santhoshkumar
- Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud Post, Poojappura, Thiruvananthapuram, Kerala, India.
| | - R Ajay Kumar
- Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud Post, Poojappura, Thiruvananthapuram, Kerala, India.
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215
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Mervai Z, Egedi K, Kovalszky I, Baghy K. Diethylnitrosamine induces lung adenocarcinoma in FVB/N mouse. BMC Cancer 2018; 18:157. [PMID: 29415661 PMCID: PMC5803903 DOI: 10.1186/s12885-018-4068-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 01/29/2018] [Indexed: 12/16/2022] Open
Abstract
Background Diethylnitrosamine is a well known carcinogen that induces cancers of various organs in mice and rats. Using FVB/N mouse strain, here we show that diethylnitrosamine induces primarily lung adenocarcinomas with modest tumor development in the liver, offering a new model to study chemical carcinogenesis in the lung. Methods Animals were exposed to a single high dose of diethylnitrosamine, and more than 70% of the mice developed lung cancer. To obtain a new transplantable tumor line, pieces of primary tumors were inoculated and maintained subcutaneously in the same mouse strain. We used immunohistochemistry to characterize the tumor for main lung adenocarcinoma markers. We searched for mutations in KRAS exon 2 and EGFR exon 19, 21 with Sanger sequencing. We also compared the normal lung tissue with the diethylnitrosamine induced primary adenocarcinoma, and with the subcutaneously maintained adenocarcinoma using Western blot technique for main cell cycle markers and to identify the main pathways. Results Primary and subcutaneous tumors express cytokeratin-7 and thyroid transcription factor-1, markers characteristic to lung adenocarcinoma. In addition, no mutations were found in the hot spot regions of KRAS and EGFR genes. We found high mTOR activation, but the level of p-Akt Ser473 and p-Akt Thr308 decreased in the tumorous samples. Conclusions We established a new lung adenocarcinoma model using FVB/N mouse strain and diethylnitrosamine. We believe that this new model system would be highly useful in lung cancer research. Electronic supplementary material The online version of this article (10.1186/s12885-018-4068-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zsolt Mervai
- Department of Pathology and Experimental Cancer Research, Budapest, Hungary
| | - Krisztina Egedi
- Department of Pathology and Experimental Cancer Research, Budapest, Hungary
| | - Ilona Kovalszky
- Department of Pathology and Experimental Cancer Research, Budapest, Hungary
| | - Kornélia Baghy
- Department of Pathology and Experimental Cancer Research, Budapest, Hungary.
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216
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Guo Q, Yu C, Zhang C, Li Y, Wang T, Huang Z, Wang X, Zhou W, Li Y, Qin Z, Wang C, Gao R, Nie Y, Ma Y, Shi Y, Zheng J, Yang S, Fan Y, Xiang R. Highly Selective, Potent, and Oral mTOR Inhibitor for Treatment of Cancer as Autophagy Inducer. J Med Chem 2018; 61:881-904. [PMID: 29308895 DOI: 10.1021/acs.jmedchem.7b01402] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
On the basis of novel pyrazino[2,3-c]quinolin-2(1H)-one scaffold, we designed and identified a highly selective, potent and oral mTOR inhibitor, 9m. Compound 9m showed low nanomolar activity against mTOR (IC50 = 7 nM) and greater selectivity over the related PIKK family kinases, which demonstrated only modest activity against 3 out of the 409 protein kinases. In vitro assays, compound 9m exhibited high potency against human breast and cervical cancer cells and induced tumor cell cycle arrest and autophagy. 9m inhibited cellular phosphorylation of mTORC1 (pS6 and p4E-BP1) and mTORC2 (pAKT (S473)) substrates. In T-47D xenograft mouse model, oral administration of compound 9m led to significant tumor regression without obvious toxicity. In addition, this compound showed good pharmacokinetics. Collectively, due to its high potency and selectivity, compound 9m could be used as a mTOR drug candidate.
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Affiliation(s)
- Qingxiang Guo
- School of Medicine, Nankai University , 94 Weijin Road, Tianjin 300071, China
| | - Chenhua Yu
- School of Medicine, Nankai University , 94 Weijin Road, Tianjin 300071, China
| | - Chao Zhang
- School of Medicine, Nankai University , 94 Weijin Road, Tianjin 300071, China
| | - Yongtao Li
- School of Medicine, Nankai University , 94 Weijin Road, Tianjin 300071, China
| | - Tianqi Wang
- School of Medicine, Nankai University , 94 Weijin Road, Tianjin 300071, China
| | - Zhi Huang
- School of Medicine, Nankai University , 94 Weijin Road, Tianjin 300071, China
| | - Xin Wang
- School of Medicine, Nankai University , 94 Weijin Road, Tianjin 300071, China
| | - Wei Zhou
- School of Medicine, Nankai University , 94 Weijin Road, Tianjin 300071, China
| | - Yao Li
- School of Medicine, Nankai University , 94 Weijin Road, Tianjin 300071, China
| | - Zhongxiang Qin
- School of Medicine, Nankai University , 94 Weijin Road, Tianjin 300071, China
| | - Cheng Wang
- School of Medicine, Nankai University , 94 Weijin Road, Tianjin 300071, China
| | - Ruifang Gao
- School of Medicine, Nankai University , 94 Weijin Road, Tianjin 300071, China
| | - Yongwei Nie
- School of Medicine, Nankai University , 94 Weijin Road, Tianjin 300071, China
| | - Yakun Ma
- School of Medicine, Nankai University , 94 Weijin Road, Tianjin 300071, China
| | - Yi Shi
- School of Medicine, Nankai University , 94 Weijin Road, Tianjin 300071, China
| | - Jianyu Zheng
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Collaborative Innovation Center of Chemical Science and Engineering, Nankai University , Tianjin 300071, China
| | - Shengyong Yang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu 610041, China
| | - Yan Fan
- School of Medicine, Nankai University , 94 Weijin Road, Tianjin 300071, China.,International Collaborative Laboratory of Biomedicine of the Ministry of Education , 94 Weijin Road, Tianjin 300071, China
| | - Rong Xiang
- School of Medicine, Nankai University , 94 Weijin Road, Tianjin 300071, China.,2011 Project Collaborative Innovation Center for Biotherapy of Ministry of Education , 94 Weijin Road, Tianjin 300071, China
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217
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Synergistic effect of a novel autophagy inhibitor and Quizartinib enhances cancer cell death. Cell Death Dis 2018; 9:138. [PMID: 29374185 PMCID: PMC5833862 DOI: 10.1038/s41419-017-0170-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 11/14/2017] [Accepted: 11/17/2017] [Indexed: 01/07/2023]
Abstract
Drug combinations have been increasingly applied in chemotherapy as a strategy to enhance the efficacy of anti-cancer treatment. The appropriate drug combinations may achieve synergistic effects beyond monotherapies alone. AC220 (Quizartinib), an FLT3 receptor tyrosine kinase inhibitor, developed for the treatment of AML, has been tested in phase II human clinical trials. However, AC220 as a monotherapy is not efficacious enough. In this study, we performed a small-molecule screening of 12 640 compounds in order to find a compound that increase the AC220 efficacy in chemotherapy. We identified that TAK-165, a HER2 inhibitor, even when used at low nanomolar doses in combination with AC220, was able to induce cell death in different cancer cells, but not in non-cancer cell lines. We showed that TAK-165 and AC220 act synergistically to downregulate key signaling pathways and potently induce cancer cell death. Furthermore, we demonstrated that TAK-165 inhibited autophagy in a HER2-independent manner. Finally, we showed that the combination of TAK-165 and AC220 induced cell death in cancer cells through the activation of chaperone-mediated autophagy. Overall, these findings support the strategy for using AC220 and an autophagy inhibitor such as TAK-165 in a combinatorial treatment to enhance the efficacy of cancer therapies.
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218
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Takahashi K, Nagai T, Chiba S, Nakayama K, Mizuno K. Glucose deprivation induces primary cilium formation through mTORC1 inactivation. J Cell Sci 2018; 131:jcs.208769. [PMID: 29180513 DOI: 10.1242/jcs.208769] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 11/20/2017] [Indexed: 01/14/2023] Open
Abstract
Primary cilia are antenna-like sensory organelles extending from the surface of many cell types that play critical roles in tissue development and homeostasis. Here, we examined the effect of nutrient status on primary cilium formation. Glucose deprivation significantly increased the number of ciliated cells under both serum-fed and -starved conditions. Glucose deprivation-induced ciliogenesis was suppressed by overexpression of Rheb, an activator of the mammalian target of rapamycin complex-1 (mTORC1). Inactivating mTORC1 by rapamycin treatment or Raptor knockdown significantly promoted ciliogenesis. These results indicate that glucose deprivation promotes primary cilium formation through mTORC1 inactivation. Rapamycin treatment did not promote autophagy or degradation of OFD1, a negative regulator of ciliogenesis. In contrast, rapamycin treatment increased the level of the p27KIP1 (also known as CDKN1B) cyclin-dependent kinase inhibitor, and rapamycin-induced ciliogenesis was abrogated in p27KIP1-depleted cells. These results indicate that mTORC1 inactivation induces ciliogenesis through p27KIP1 upregulation, but not through autophagy. By contrast, glucose deprivation or rapamycin treatment shortened the cilium length. Thus, glucose deprivation and subsequent inactivation of mTORC1 play dual roles in ciliogenesis: triggering primary cilium formation and shortening cilium length.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Kengo Takahashi
- Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Tomoaki Nagai
- Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Shuhei Chiba
- Department of Genetic Disease Research, Osaka City University, Graduate School of Medicine, Osaka 545-8585, Japan
| | - Keiko Nakayama
- Department of Cell Proliferation, United Center for Advanced Research and Translational Medicine, Graduate School of Medicine, Tohoku University, Sendai, Miyagi 980-8575, Japan
| | - Kensaku Mizuno
- Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
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219
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Trilla-Fuertes L, Gámez-Pozo A, Arevalillo JM, Díaz-Almirón M, Prado-Vázquez G, Zapater-Moros A, Navarro H, Aras-López R, Dapía I, López-Vacas R, Nanni P, Llorente-Armijo S, Arias P, Borobia AM, Maín P, Feliú J, Espinosa E, Fresno Vara JÁ. Molecular characterization of breast cancer cell response to metabolic drugs. Oncotarget 2018. [PMID: 29515760 PMCID: PMC5839391 DOI: 10.18632/oncotarget.24047] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Metabolic reprogramming is a hallmark of cancer. It has been described that breast cancer subtypes present metabolism differences and this fact enables the possibility of using metabolic inhibitors as targeted drugs in specific scenarios. In this study, breast cancer cell lines were treated with metformin and rapamycin, showing a heterogeneous response to treatment and leading to cell cycle disruption. The genetic causes and molecular effects of this differential response were characterized by means of SNP genotyping and mass spectrometry-based proteomics. Protein expression was analyzed using probabilistic graphical models, showing that treatments elicit various responses in some biological processes such as transcription. Moreover, flux balance analysis using protein expression values showed that predicted growth rates were comparable with cell viability measurements and suggesting an increase in reactive oxygen species response enzymes due to metformin treatment. In addition, a method to assess flux differences in whole pathways was proposed. Our results show that these diverse approaches provide complementary information and allow us to suggest hypotheses about the response to drugs that target metabolism and their mechanisms of action.
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Affiliation(s)
- Lucía Trilla-Fuertes
- Molecular Oncology and Pathology Lab, Institute of Medical and Molecular Genetics-INGEMM, La Paz University Hospital-IdiPAZ, Madrid, Spain.,Biomedica Molecular Medicine SL, Madrid, Spain
| | - Angelo Gámez-Pozo
- Molecular Oncology and Pathology Lab, Institute of Medical and Molecular Genetics-INGEMM, La Paz University Hospital-IdiPAZ, Madrid, Spain.,Biomedica Molecular Medicine SL, Madrid, Spain
| | - Jorge M Arevalillo
- Operational Research and Numerical Analysis, National Distance Education University (UNED), Madrid, Spain
| | | | - Guillermo Prado-Vázquez
- Molecular Oncology and Pathology Lab, Institute of Medical and Molecular Genetics-INGEMM, La Paz University Hospital-IdiPAZ, Madrid, Spain
| | - Andrea Zapater-Moros
- Molecular Oncology and Pathology Lab, Institute of Medical and Molecular Genetics-INGEMM, La Paz University Hospital-IdiPAZ, Madrid, Spain
| | - Hilario Navarro
- Operational Research and Numerical Analysis, National Distance Education University (UNED), Madrid, Spain
| | - Rosa Aras-López
- Congenital Malformations Lab, Institute of Medical and Molecular Genetics-INGEMM, La Paz University Hospital, IdiPAZ, Madrid, Spain
| | - Irene Dapía
- Pharmacogenetics Lab, Institute of Medical and Molecular Genetics-INGEMM, La Paz University Hospital-IdiPAZ, Autonomous University of Madrid, Madrid, Spain.,Biomedical Research Networking Center on Rare Diseases-CIBERER, ISCIII, Madrid, Spain
| | - Rocío López-Vacas
- Molecular Oncology and Pathology Lab, Institute of Medical and Molecular Genetics-INGEMM, La Paz University Hospital-IdiPAZ, Madrid, Spain
| | - Paolo Nanni
- Functional Genomics Center Zurich, University of Zurich/ETH Zurich, Zurich, Switzerland
| | - Sara Llorente-Armijo
- Molecular Oncology and Pathology Lab, Institute of Medical and Molecular Genetics-INGEMM, La Paz University Hospital-IdiPAZ, Madrid, Spain
| | - Pedro Arias
- Pharmacogenetics Lab, Institute of Medical and Molecular Genetics-INGEMM, La Paz University Hospital-IdiPAZ, Autonomous University of Madrid, Madrid, Spain.,Biomedical Research Networking Center on Rare Diseases-CIBERER, ISCIII, Madrid, Spain
| | - Alberto M Borobia
- Clinical Pharmacology Department, La Paz University Hospital School of Medicine, IdiPAZ, Autonomous University of Madrid, Madrid, Spain
| | - Paloma Maín
- Department of Statistics and Operations Research, Faculty of Mathematics, Complutense University of Madrid, Madrid, Spain
| | - Jaime Feliú
- Medical Oncology Service, La Paz University Hospital-IdiPAZ, Madrid, Spain.,Biomedical Research Networking Center on Oncology-CIBERONC, ISCIII, Madrid, Spain.,Cátedra UAM-AMGEN, Universidad Autónoma de Madrid, Madrid, Spain
| | - Enrique Espinosa
- Medical Oncology Service, La Paz University Hospital-IdiPAZ, Madrid, Spain.,Biomedical Research Networking Center on Oncology-CIBERONC, ISCIII, Madrid, Spain
| | - Juan Ángel Fresno Vara
- Molecular Oncology and Pathology Lab, Institute of Medical and Molecular Genetics-INGEMM, La Paz University Hospital-IdiPAZ, Madrid, Spain.,Biomedica Molecular Medicine SL, Madrid, Spain.,Biomedical Research Networking Center on Oncology-CIBERONC, ISCIII, Madrid, Spain
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220
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Rad E, Murray JT, Tee AR. Oncogenic Signalling through Mechanistic Target of Rapamycin (mTOR): A Driver of Metabolic Transformation and Cancer Progression. Cancers (Basel) 2018; 10:cancers10010005. [PMID: 29301334 PMCID: PMC5789355 DOI: 10.3390/cancers10010005] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 12/27/2017] [Accepted: 12/28/2017] [Indexed: 12/29/2022] Open
Abstract
Throughout the years, research into signalling pathways involved in cancer progression has led to many discoveries of which mechanistic target of rapamycin (mTOR) is a key player. mTOR is a master regulator of cell growth control. mTOR is historically known to promote cell growth by enhancing the efficiency of protein translation. Research in the last decade has revealed that mTOR’s role in promoting cell growth is much more multifaceted. While mTOR is necessary for normal human physiology, cancer cells take advantage of mTOR signalling to drive their neoplastic growth and progression. Oncogenic signal transduction through mTOR is a common occurrence in cancer, leading to metabolic transformation, enhanced proliferative drive and increased metastatic potential through neovascularisation. This review focuses on the downstream mTOR-regulated processes that are implicated in the “hallmarks” of cancer with focus on mTOR’s involvement in proliferative signalling, metabolic reprogramming, angiogenesis and metastasis.
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Affiliation(s)
- Ellie Rad
- Division of Cancer and Genetics, Cardiff University, Heath Park, Cardiff CF14 4XN, UK.
- School of Biochemistry & Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.
| | - James T Murray
- School of Biochemistry & Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.
| | - Andrew R Tee
- Division of Cancer and Genetics, Cardiff University, Heath Park, Cardiff CF14 4XN, UK.
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221
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Xu Z, Chang CC, Li M, Zhang QY, Vasilescu ERM, D’Agati V, Floratos A, Vlad G, Suciu-Foca N. ILT3.Fc–CD166 Interaction Induces Inactivation of p70 S6 Kinase and Inhibits Tumor Cell Growth. THE JOURNAL OF IMMUNOLOGY 2017; 200:1207-1219. [DOI: 10.4049/jimmunol.1700553] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 11/29/2017] [Indexed: 01/17/2023]
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222
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Zhang Z, Chen Q, Zhang J, Wang Y, Hu X, Yin S, He M, Guan S, Qin W, Xiao Q, Zhao H, Yao W, Wu H, Wei M. Associations of genetic polymorphisms in pTEN/AKT/mTOR signaling pathway genes with cancer risk: A meta-analysis in Asian population. Sci Rep 2017; 7:17844. [PMID: 29259266 PMCID: PMC5736732 DOI: 10.1038/s41598-017-17250-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 11/23/2017] [Indexed: 12/14/2022] Open
Abstract
The pTEN/AKT/mTOR signaling pathways play a critical role in balancing cell proliferation, differentiation, and survival. Recent studies researched the associations of core genes in the pTEN/AKT/mTOR pathway polymorphisms with the cancer susceptibility; however, the results are inconclusive. Therefore, a systematically meta-analysis was performed to evaluate the association between the five SNPs (mTOR rs2295080 and rs2536, AKT1 rs2494750 and rs2494752, pTEN rs701848) and cancer risk by systematic review of the literature in 31 eligible studies. The results showed a significant decreased risk between rs2295080 TG, GG genotype, and GG/TG genotypes and overall cancer [TG vs.TT: OR(95% CI) = 0.82(0.76, 0.89), GG/TG vs. TT: OR(95% CI) = 0.82(0.76, 0.88), and GG vs. TG/TT: OR(95% CI) = 0.67(0.51, 0.88)] and the subgroup of urinary system cancer and digestive system cancer. Moreover, the SNP rs701848 CC, TC genotype showed significantly increased the overall cancer risk both in dominant model [CC/TC vs. TT: OR(95% CI) = 1.25(1.15, 1.36)] and recessive model [CC vs. TC/TT: OR(95% CI) = 1.20(1.09, 1.32)], and digestive system cancer and urinary system cancer. In addition, AG genotype and GG/AG genotype of rs2494752 was associated with increased risk of cancer. Therefore, this meta-analysis provided genetic risk factors for carcinogenesis and the most valid cancer prevalence estimate for Asian population.
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Affiliation(s)
- Zhen Zhang
- Department of Pharmacology, School of Pharmacy, Liaoning Key Laboratory of Molecular Targeted Anti-Tumor Drug Development and Evaluation, China Medical University, Shenyang, 110122, P. R. China
| | - Qiuchen Chen
- Department of Pharmacology, School of Pharmacy, Liaoning Key Laboratory of Molecular Targeted Anti-Tumor Drug Development and Evaluation, China Medical University, Shenyang, 110122, P. R. China
| | - Jing Zhang
- Department of Pharmacology, School of Pharmacy, Liaoning Key Laboratory of Molecular Targeted Anti-Tumor Drug Development and Evaluation, China Medical University, Shenyang, 110122, P. R. China
| | - Yilin Wang
- Department of Pharmacology, School of Pharmacy, Liaoning Key Laboratory of Molecular Targeted Anti-Tumor Drug Development and Evaluation, China Medical University, Shenyang, 110122, P. R. China
| | - Xiaoyun Hu
- Department of Pharmacology, School of Pharmacy, Liaoning Key Laboratory of Molecular Targeted Anti-Tumor Drug Development and Evaluation, China Medical University, Shenyang, 110122, P. R. China
| | - Sainan Yin
- Department of Pharmacology, School of Pharmacy, Liaoning Key Laboratory of Molecular Targeted Anti-Tumor Drug Development and Evaluation, China Medical University, Shenyang, 110122, P. R. China
| | - Miao He
- Department of Pharmacology, School of Pharmacy, Liaoning Key Laboratory of Molecular Targeted Anti-Tumor Drug Development and Evaluation, China Medical University, Shenyang, 110122, P. R. China
| | - Shu Guan
- Department of Breast Surgery, First Hospital of China Medical University, Shenyang, 110001, P. R. China
| | - Wenyan Qin
- Department of Pharmacology, School of Pharmacy, Liaoning Key Laboratory of Molecular Targeted Anti-Tumor Drug Development and Evaluation, China Medical University, Shenyang, 110122, P. R. China
| | - Qinghuan Xiao
- Department of Ion Channel Pharmacology, School of Pharmacy, China Medical University, Shenyang, 110122, P.R. China
| | - Haishan Zhao
- Department of Pharmacology, School of Pharmacy, Liaoning Key Laboratory of Molecular Targeted Anti-Tumor Drug Development and Evaluation, China Medical University, Shenyang, 110122, P. R. China
| | - Weifan Yao
- Department of Pharmacology, School of Pharmacy, Liaoning Key Laboratory of Molecular Targeted Anti-Tumor Drug Development and Evaluation, China Medical University, Shenyang, 110122, P. R. China
| | - Huizhe Wu
- Department of Pharmacology, School of Pharmacy, Liaoning Key Laboratory of Molecular Targeted Anti-Tumor Drug Development and Evaluation, China Medical University, Shenyang, 110122, P. R. China.
| | - Minjie Wei
- Department of Pharmacology, School of Pharmacy, Liaoning Key Laboratory of Molecular Targeted Anti-Tumor Drug Development and Evaluation, China Medical University, Shenyang, 110122, P. R. China.
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223
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Szereszewski KE, Storey KB. Translational regulation in the anoxic turtle, Trachemys scripta elegans. Mol Cell Biochem 2017; 445:13-23. [PMID: 29243067 DOI: 10.1007/s11010-017-3247-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 12/08/2017] [Indexed: 01/03/2023]
Abstract
The red-eared slider turtle (Trachemys scripta elegans), has developed remarkable adaptive mechanisms for coping with decreased oxygen availability during winter when lakes and ponds become covered with ice. Strategies for enduring anoxia tolerance include an increase in fermentable fuel reserves to support anaerobic glycolysis, the buffering of end products to minimize acidosis, altered expression in crucial survival genes, and strong metabolic rate suppression to minimize ATP-expensive metabolic processes such as protein synthesis. The mammalian target of rapamycin (mTOR) is at the center of the insulin-signaling pathway that regulates protein translation. The present study analyzed the responses of the mTOR signaling pathway to 5 (5H) or 20 h (20H) of anoxic submergence in liver and skeletal muscle of T. scripta elegans with a particular focus on regulatory changes in the phosphorylation states of targets. The data showed that phosphorylation of multiple mTOR targets was suppressed in skeletal muscle, but activated in the liver. Phosphorylated mTORSer2448 showed no change in skeletal muscle but had increased by approximately 4.5-fold in the liver after 20H of anoxia. The phosphorylation states of upstream positive regulators of mTOR (p-PDK-1Ser241, p-AKTSer473, and protein levels of GβL), the relative levels of dephosphorylated active PTEN, as well as phosphorylation state of negative regulators (TSC2Thr1462, p-PRAS40Thr246) were generally found to be differentially regulated in skeletal muscle and in liver. Downstream targets of mTOR (p-p70 S6KThr389, p-S6Ser235, PABP, p-4E-BP1Thr37/46, and p-eIF4ESer209) were generally unchanged in skeletal muscle but upregulated in most targets in liver. These findings indicate that protein synthesis is enhanced in the liver and suggests an increase in the synthesis of crucial proteins required for anoxic survival.
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Affiliation(s)
- Kama E Szereszewski
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Kenneth B Storey
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada.
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224
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Huang S, Lin X, Deng X, Luo X, Fang W, Luo R. Decreased cytoplasmic expression of Raptor correlates with disease progression and unfavorable prognosis in hepatocellular carcinoma. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2017; 10:11789-11796. [PMID: 31966542 PMCID: PMC6966046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 11/08/2017] [Indexed: 06/10/2023]
Abstract
The purpose of the present study is to explore the correlation between regulatory associated protein of mTOR (Raptor) and clinicopathologic features in hepatocellular carcinoma (HCC), including patient survival. Immunohistochemistry was used to examine the expression of Raptor in 90 HCC tissues and peritumoral liver tissues. The relationship between tumor Raptor expression and clinicopathologic characteristics was analyzed. Survival curves were plotted using the Kaplan-Meier method and compared using the log-rank test. The significance of various survival variables was analyzed using multivariate Cox proportional hazards model. We found that Raptor protein was detected in cytoplasmic compartment. Significantly lower Raptor expression was observed in HCC compared to peritumoral liver cells (P=0.048). The tumor expression levels of Raptor significantly inversely correlated with clinical stage (P=0.026). Patients with high Raptor expression had better recurrence-free survival (P=0.010). Further, we observed that Raptor expression was positively associated with recurrence-free survival of HCC patients with tumor capsule (P=0.043) and without portal vein tumor thrombus (P=0.033) classifications. Finally, we found that Raptor was an independent prognostic factor of recurrence-free survival for patients with HCC (P=0.042). To conclude, our results support that decreased cytoplasmic expression of Raptor is a potentially unfavorable factor in the progression and prognosis of HCC.
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Affiliation(s)
- Shisi Huang
- Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical UniversityGuangzhou, China
- Department of Oncology, Haikou Municipal People’s Hospital and Central South University Xiangya Medical College Affiliated HospitalHaikou, China
| | - Xian Lin
- Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical UniversityGuangzhou, China
| | - Xiaojie Deng
- Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical UniversityGuangzhou, China
| | - Xiaojun Luo
- Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical UniversityGuangzhou, China
| | - Weiyi Fang
- Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical UniversityGuangzhou, China
| | - Rongcheng Luo
- Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical UniversityGuangzhou, China
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225
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Mishall KM, Beadnell TC, Kuenzi BM, Klimczak DM, Superti-Furga G, Rix U, Schweppe RE. Sustained activation of the AKT/mTOR and MAP kinase pathways mediate resistance to the Src inhibitor, dasatinib, in thyroid cancer. Oncotarget 2017; 8:103014-103031. [PMID: 29262541 PMCID: PMC5732707 DOI: 10.18632/oncotarget.20488] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 07/23/2017] [Indexed: 12/11/2022] Open
Abstract
New targeted therapies are needed for advanced thyroid cancer. Our lab has shown that Src is a key mediator of tumorigenic processes in thyroid cancer. However, single-agent Src inhibitors have had limited efficacy in solid tumors. In order to more effectively target Src in the clinic, our lab has previously generated four thyroid cancer cell lines that are resistant to dasatinib through gradual dose escalation. We further tested two additional Src inhibitors and shown the dasatinib-resistant (DasRes) cells exhibit cross-resistance to saracatinib, but are sensitive to bosutinib, suggesting that unique off-targets of bosutinib play an important role in mediating sensitivity to bosutinib. To identify the kinases targeted by dasatinib and bosutinib, we utilized an unbiased compound centric chemical proteomics screen. We identified 33 kinases that were enriched in the bosutinib pull down. Using the STRING database to map protein-protein interactions of the unique bosutinib targets, we identified a signaling axis which included mTOR, FAK, and MEK. Inhibition of the mTOR, MEK, and Src/FAK nodes simultaneously was the most effective at reducing cell growth and survival. Overall, these studies have identified key mediators of Src inhibitor resistance, and show that targeting these signaling nodes are necessary for anti-tumor efficacy.
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Affiliation(s)
- Katie M. Mishall
- Department of Medicine, Division of Endocrinology, Metabolism and Diabetes, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Thomas C. Beadnell
- Department of Medicine, Division of Endocrinology, Metabolism and Diabetes, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Brent M. Kuenzi
- Department of Drug Discovery, Moffitt Cancer Center & Research Institute, Tampa, Florida, USA
- Cancer Biology PhD Program, University of South Florida, Tampa, Florida, USA
| | - Dorothy M. Klimczak
- Department of Medicine, Division of Endocrinology, Metabolism and Diabetes, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Giulio Superti-Furga
- CeMM Research Center for Molecular Medicine, Austrian Academy of Sciences, Vienna, Austria
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Uwe Rix
- Department of Drug Discovery, Moffitt Cancer Center & Research Institute, Tampa, Florida, USA
| | - Rebecca E. Schweppe
- Department of Medicine, Division of Endocrinology, Metabolism and Diabetes, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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226
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Abstract
Parthenotes are characterized by poor in vitro developmental potential either due to the ploidy status or the absence of paternal factors. In the present study, we demonstrate the beneficial role of sperm-derived factors (SDF) on the in vitro development of mouse parthenotes. Mature (MII) oocytes collected from superovulated Swiss albino mice were activated using strontium chloride (SrCl2) in the presence or absence of various concentrations of SDF in M16 medium. The presence of SDF in activation medium did not have any significant influence on the activation rate. However, a significant increase in the developmental potential of the embryos and increased blastocyst rate (P < 0.01) was observed at 50 µg/ml concentration. Furthermore, the activated oocytes from this group exhibited early cleavage and cortical distribution of cortical granules that was similar to that of normally fertilized zygotes. Culturing 2-cell stage parthenotes in the presence of SDF significantly improved the developmental potential (P < 0.05) indicating that they also play a significant role in embryo development. In conclusion, artificial activation of oocytes with SDF can improve the developmental potential of parthenotes in vitro.
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227
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Marques-Ramos A, Candeias MM, Menezes J, Lacerda R, Willcocks M, Teixeira A, Locker N, Romão L. Cap-independent translation ensures mTOR expression and function upon protein synthesis inhibition. RNA (NEW YORK, N.Y.) 2017; 23:1712-1728. [PMID: 28821580 PMCID: PMC5648038 DOI: 10.1261/rna.063040.117] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 08/15/2017] [Indexed: 06/07/2023]
Abstract
The mechanistic/mammalian target of rapamycin (mTOR) is a conserved serine/threonine kinase that integrates cellular signals from the nutrient and energy status to act, namely, on the protein synthesis machinery. While major advances have emerged regarding the regulators and effects of the mTOR signaling pathway, little is known about the regulation of mTOR gene expression. Here, we show that the human mTOR transcript can be translated in a cap-independent manner, and that its 5' untranslated region (UTR) is a highly folded RNA scaffold capable of binding directly to the 40S ribosomal subunit. We further demonstrate that mTOR is able to bypass the cap requirement for translation both in normal and hypoxic conditions. Moreover, our data reveal that the cap-independent translation of mTOR is necessary for its ability to induce cell-cycle progression into S phase. These results suggest a novel regulatory mechanism for mTOR gene expression that integrates the global protein synthesis changes induced by translational inhibitory conditions.
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Affiliation(s)
- Ana Marques-Ramos
- Departamento de Genética Humana, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016 Lisboa, Portugal
- Biosystems and Integrative Sciences Institute (BioISI), Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Marco M Candeias
- Departamento de Genética Humana, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016 Lisboa, Portugal
- Laboratory of Bioimaging and Cell Signaling, Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Juliane Menezes
- Departamento de Genética Humana, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016 Lisboa, Portugal
- Biosystems and Integrative Sciences Institute (BioISI), Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Rafaela Lacerda
- Departamento de Genética Humana, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016 Lisboa, Portugal
- Biosystems and Integrative Sciences Institute (BioISI), Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Margaret Willcocks
- Microbial and Cellular Sciences Department, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7TE, United Kingdom
| | - Alexandre Teixeira
- Departamento de Genética Humana, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016 Lisboa, Portugal
| | - Nicolas Locker
- Microbial and Cellular Sciences Department, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7TE, United Kingdom
| | - Luísa Romão
- Departamento de Genética Humana, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016 Lisboa, Portugal
- Biosystems and Integrative Sciences Institute (BioISI), Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
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228
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Satow R, Inagaki S, Kato C, Shimozawa M, Fukami K. Identification of zinc finger protein of the cerebellum 5 as a survival factor of prostate and colorectal cancer cells. Cancer Sci 2017; 108:2405-2412. [PMID: 29024195 PMCID: PMC5715345 DOI: 10.1111/cas.13419] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 10/01/2017] [Accepted: 10/04/2017] [Indexed: 12/18/2022] Open
Abstract
Identification of specific drug targets is very important for cancer therapy. We recently identified zinc finger protein of the cerebellum 5 (ZIC5) as a factor that promotes melanoma aggressiveness by platelet-derived growth factor D (PDGFD) expression. However, its roles in other cancer types remain largely unknown. Here we determined the roles of ZIC5 in prostate cancer (PCa) and colorectal cancer (CRC) cells. Results showed that ZIC5 was highly expressed in CRC and dedifferentiated PCa tissues, whereas little expression was observed in relevant normal tissues. Knockdown of ZIC5 decreased proliferation of several PCa and CRC cell lines with induction of cell death. ZIC5 knockdown significantly suppressed PDGFD expression transcriptionally, and PDGFD suppression also decreased proliferation of PCa and CRC cell lines. In addition, suppression of ZIC5 or PDGFD expression decreased levels of phosphorylated focal adhesion kinase (FAK) and signal transducer and activator of transcription 3 (STAT3) which are associated with PCa and CRC aggressiveness. Furthermore, knockdown of ZIC5 or PDGFD enhanced death of PCa and CRC cells induced by the anti-cancer drugs docetaxel or oxaliplatin, respectively. These results suggest that ZIC5 and PDGFD promote survival of PCa and CRC cells by enhancing FAK and STAT3 activity, and that the roles of ZIC5 are consistent across several cancer types.
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Affiliation(s)
- Reiko Satow
- Laboratory of Genome and Biosignals, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan.,AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, Japan
| | - Shota Inagaki
- Laboratory of Genome and Biosignals, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Chiaki Kato
- Laboratory of Genome and Biosignals, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Makoto Shimozawa
- Laboratory of Genome and Biosignals, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Kiyoko Fukami
- Laboratory of Genome and Biosignals, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan.,AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, Japan
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229
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Jones E, Inoki K. Microphthalmia-associated transcription factors activate mTORC1 through RagD GTPase gene expression. Transl Cancer Res 2017; 6:S1234-S1238. [PMID: 31187024 PMCID: PMC6557429 DOI: 10.21037/tcr.2017.09.31] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Edith Jones
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Molecular and Integrative Physiology, Ann Arbor, MI, USA
| | - Ken Inoki
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Molecular and Integrative Physiology, Ann Arbor, MI, USA
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
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230
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Han KH, Kim AK, Kim MH, Kim DH, Go HN, Kang D, Chang JW, Choi SW, Kang KS, Kim DI. Protein profiling and angiogenic effect of hypoxia-cultured human umbilical cord blood-derived mesenchymal stem cells in hindlimb ischemia. Tissue Cell 2017; 49:680-690. [PMID: 28958480 DOI: 10.1016/j.tice.2017.09.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 09/05/2017] [Accepted: 09/14/2017] [Indexed: 12/19/2022]
Abstract
The aim of the present study was to investigate protein profiles of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) cultured in normoxic (21% O2) and hypoxic (1% O2) conditions, and evaluate oxygenation effects on angiogenesis in an ischemic hindlimb mouse model using a modified ischemic scoring system. Hypoxic conditions did not change the expression of phenotypic markers and increased adipogenesis and chondrogenesis. Epidermal growth factor (EGF), transforming growth factor alpha (TGF-α), TGF-β RII, and vascular endothelial growth factor (VEGF) were upregulated in the conditioned medium of hypoxic hUCB-MSCs, which are commonly related to angiogenesis and proliferation of biological processes by Gene Ontology. In the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, significant enrichment of the phosphorylation of abelson murine leukemia viral oncogene homolog 1 (ABL1) (Phospho-Tyr204) and B-cell lymphoma-extra large (BCL-XL) (Phospho-Thr47) as anti-apoptotic pathways was observed in hypoxic hUCB-MSCs. Furthermore, hypoxic conditions induced proliferation and migration, and reduced apoptosis of hUCB-MSCs in vitro. Based on the results of protein antibody array, we evaluated the angiogenic effects of injecting normoxic or hypoxic hUCB-MSCs (1×106) into the ischemic hindlimb muscles of mice. Ischemic scores and capillary generation were significantly greater in the hypoxic hUCB-MSC injection group than in the normoxic hUCB-MSC group. Our findings demonstrate that culturing hUCB-MSCs in hypoxic conditions not only significantly enriches phosphorylation in the anti-apoptosis pathway and enhances the secretion of several angiogenic proteins from cells, but also alleviates ischemic injury of hindlimb of mice.
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Affiliation(s)
- Kyu-Hyun Han
- Division of Vascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea
| | - Ae-Kyeong Kim
- Division of Vascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea
| | - Min-Hee Kim
- Division of Vascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea
| | - Do-Hyung Kim
- Division of Vascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea
| | - Ha-Nl Go
- Division of Vascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea
| | - Donglim Kang
- Division of Vascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea
| | - Jong Wook Chang
- Stem Cell & Regenerative Medicine Institute, Research Institute for Future Medicine, Samsung Medical Center, Seoul 06351, Republic of Korea
| | - Soon Won Choi
- Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 151-747, Republic of Korea
| | - Kyung-Sun Kang
- Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 151-747, Republic of Korea
| | - Dong-Ik Kim
- Division of Vascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea.
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231
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Na EJ, Nam HY, Park J, Chung MA, Woo HA, Kim HJ. PI3K-mTOR-S6K Signaling Mediates Neuronal Viability via Collapsin Response Mediator Protein-2 Expression. Front Mol Neurosci 2017; 10:288. [PMID: 28966575 PMCID: PMC5605571 DOI: 10.3389/fnmol.2017.00288] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 08/25/2017] [Indexed: 01/22/2023] Open
Abstract
Collapsin response mediator protein (CRMP)-2 and the mammalian target of rapamycin complex 1 (mTORC1) signaling pathway are associated with common physiological functions such as neuronal polarity, axonal outgrowth and synaptic strength, as well as various brain disorders including epilepsy. But, their regulatory and functional links are unclear. Alterations in CRMP-2 expression that lead to its functional changes are implicated in brain disorders such as epilepsy. Here, we investigate whether changes in CRMP-2 expression, possibly regulated by mTOR-related signaling, correlates with neuronal growth and viability. Inhibition of mTOR and/or phosphoinositol-3-kinase (PI3K) led to deceased p-S6K, and p-S6 signals also reduced CRMP-2 expression. These changes corresponded to inhibition of neuronal viability and proliferation in cultured hippocampal HT-22 cells under both basal serum-free and serum- or insulin-induced mTOR pathway-activated conditions. CRMP-2 expression tended to be increased by mTOR activation, indicated by an increase in p-S6/S6 level, in pentylentetrazole (PTZ)-induced epileptic rat hippocampal tissues was also significantly reduced by mTOR inhibition. Knockdown of CRMP-2 by si-RNA reduced the neuronal viability without changes in mTOR signaling, and overexpression of CRMP-2 recovered the glutamate-induced neurotoxicity and decrease of mTOR signaling in HT-22 cells. In conclusion, CRMP-2 protein expression controlled by the PI3K-mTOR-S6K signaling axis exerts its important functional roles in neuronal growth and survival.
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Affiliation(s)
- Eun J Na
- College of Pharmacy, Research Institute of Pharmaceutical Sciences, Ewha Womans UniversitySeoul, South Korea
| | - Hye Yeon Nam
- College of Pharmacy, Research Institute of Pharmaceutical Sciences, Ewha Womans UniversitySeoul, South Korea
| | - Jiyoung Park
- College of Pharmacy, Research Institute of Pharmaceutical Sciences, Ewha Womans UniversitySeoul, South Korea
| | - Myung Ah Chung
- College of Pharmacy, Research Institute of Pharmaceutical Sciences, Ewha Womans UniversitySeoul, South Korea
| | - Hyun Ae Woo
- College of Pharmacy, Research Institute of Pharmaceutical Sciences, Ewha Womans UniversitySeoul, South Korea
| | - Hwa-Jung Kim
- College of Pharmacy, Research Institute of Pharmaceutical Sciences, Ewha Womans UniversitySeoul, South Korea
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232
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Abstract
During antibody affinity maturation, germinal center (GC) B cells cycle between affinity-driven selection in the light zone (LZ) and proliferation and somatic hypermutation in the dark zone (DZ). Although selection of GC B cells is triggered by antigen-dependent signals delivered in the LZ, DZ proliferation occurs in the absence of such signals. We show that positive selection triggered by T cell help activates the mechanistic target of rapamycin complex 1 (mTORC1), which promotes the anabolic program that supports DZ proliferation. Blocking mTORC1 prior to growth prevented clonal expansion, whereas blockade after cells reached peak size had little to no effect. Conversely, constitutively active mTORC1 led to DZ enrichment but loss of competitiveness and impaired affinity maturation. Thus, mTORC1 activation is required for fueling B cells prior to DZ proliferation rather than for allowing cell-cycle progression itself and must be regulated dynamically during cyclic re-entry to ensure efficient affinity-based selection.
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233
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Romero-Pozuelo J, Demetriades C, Schroeder P, Teleman AA. CycD/Cdk4 and Discontinuities in Dpp Signaling Activate TORC1 in the Drosophila Wing Disc. Dev Cell 2017; 42:376-387.e5. [PMID: 28829945 DOI: 10.1016/j.devcel.2017.07.019] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 06/19/2017] [Accepted: 07/23/2017] [Indexed: 01/08/2023]
Abstract
The molecular mechanisms regulating animal tissue size during development are unclear. This question has been extensively studied in the Drosophila wing disc. Although cell growth is regulated by the kinase TORC1, no readout exists to visualize TORC1 activity in situ in Drosophila. Both the cell cycle and the morphogen Dpp are linked to tissue growth, but whether they regulate TORC1 activity is not known. We develop here an anti-phospho-dRpS6 antibody that detects TORC1 activity in situ. We find, unexpectedly, that TORC1 activity in the wing disc is patchy. This is caused by elevated TORC1 activity at the cell cycle G1/S transition due to CycD/Cdk4 phosphorylating TSC1/2. We find that TORC1 is also activated independently of CycD/Cdk4 when cells with different levels of Dpp signaling or Brinker protein are juxtaposed. We thereby characterize the spatial distribution of TORC1 activity in a developing organ.
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Affiliation(s)
- Jesús Romero-Pozuelo
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; Heidelberg University, 69120 Heidelberg, Germany
| | - Constantinos Demetriades
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; Heidelberg University, 69120 Heidelberg, Germany
| | - Phillip Schroeder
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; Heidelberg University, 69120 Heidelberg, Germany
| | - Aurelio A Teleman
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; Heidelberg University, 69120 Heidelberg, Germany.
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234
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Vignali PDA, Barbi J, Pan F. Metabolic Regulation of T Cell Immunity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1011:87-130. [DOI: 10.1007/978-94-024-1170-6_2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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235
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Yu CC, Hung SK, Lin HY, Chiou WY, Lee MS, Liao HF, Huang HB, Ho HC, Su YC. Targeting the PI3K/AKT/mTOR signaling pathway as an effectively radiosensitizing strategy for treating human oral squamous cell carcinoma in vitro and in vivo. Oncotarget 2017; 8:68641-68653. [PMID: 28978144 PMCID: PMC5620284 DOI: 10.18632/oncotarget.19817] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 06/20/2017] [Indexed: 12/31/2022] Open
Abstract
Radiation therapy (RT) is the current standard adjuvant approach for oral squamous cell carcinoma (OSCC) patients. Radioresistance is a major contributor to radiotherapy failure. In this study, we used patient-derived cells and a radiation-resistant cell line in vitro and in vivo for two purposes: evaluate the anti-tumor effects and understand the mechanisms in the dual PI3K/mTOR signaling pathway regulation of radiosensitization. Our findings indicate that in OML1-R cells, the radioresistance phenotype is associated with activation of the PI3K/AKT/mTOR signaling pathway. Compared to a combination of PI3K or mTOR inhibitors and radiation, dual blockade of the PI3K and mTOR kinases significantly improved radiation efficacy in oral cancer and patient-derived OSCC cells. Dual PI3K/mTOR inhibition enhanced the effect of radiation by inhibiting AKT/mTOR signaling pathways and caused G1 phase arrest, which is associated with downregulation of cyclin D1/CDK4 activity, leading to growth inhibition. In nude mice xenografted with radioresistant OML1-R cells, the combined treatment was also more effective than RT alone in reducing tumor growth. This treatment was also demonstrated to be dependent on the inhibition of protein kinase-dependent S6 kinase pathway and eIF4E-mediated cap-dependent translation. These findings indicate that activation of the PI3K/AKT/mTOR signaling pathway has a role in radioresistance of OSCC. We determined that a PI3K/mTOR inhibitor combined with radiation exhibits synergistic inhibition of the AKT/mTOR axis and induces cell cycle arrest. Our results show the therapeutic potential of drugs targeting the PI3K/AKT/mTOR signaling pathway should be new candidate drugs for radiosensitization in radiotherapy.
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Affiliation(s)
- Chih-Chia Yu
- Department of Life Science and Institute of Molecular Biology, National Chung Cheng University, Chia-Yi, Taiwan, R.O.C.,Department of Radiation Oncology, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taiwan, R.O.C
| | - Shih-Kai Hung
- Department of Radiation Oncology, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taiwan, R.O.C.,School of Medicine, Tzu Chi University, Hualian, Taiwan, R.O.C
| | - Hon-Yi Lin
- Department of Radiation Oncology, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taiwan, R.O.C.,School of Medicine, Tzu Chi University, Hualian, Taiwan, R.O.C
| | - Wen-Yen Chiou
- Department of Radiation Oncology, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taiwan, R.O.C.,School of Medicine, Tzu Chi University, Hualian, Taiwan, R.O.C
| | - Moon-Sing Lee
- Department of Radiation Oncology, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taiwan, R.O.C.,School of Medicine, Tzu Chi University, Hualian, Taiwan, R.O.C
| | - Hui-Fen Liao
- Department of Biochemical Science and Technology, National Chiayi University, Chia-Yi, Taiwan, R.O.C
| | - Hsien-Bin Huang
- Department of Life Science and Institute of Molecular Biology, National Chung Cheng University, Chia-Yi, Taiwan, R.O.C
| | - Hsu-Chueh Ho
- Department of Otolaryngology, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taiwan, R.O.C
| | - Yu-Chieh Su
- Division of Hematology and Oncology, E-Da Hospital, Kaohsiung, Taiwan.,School of Medicine, I-Shou University, Kaohsiung, Taiwan, R.O.C
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Rapamycin inhibits spermatogenesis by changing the autophagy status through suppressing mechanistic target of rapamycin-p70S6 kinase in male rats. Mol Med Rep 2017; 16:4029-4037. [PMID: 28765938 PMCID: PMC5646984 DOI: 10.3892/mmr.2017.7120] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Accepted: 05/24/2017] [Indexed: 01/22/2023] Open
Abstract
Rapamycin (sirolimus) is an antiproliferative drug that has been widely used in the clinic as an immunosuppressant and a potential anticancer agent. Certain reports have indicated that rapamycin may induce male infertility through impairing sperm quality. The present study investigated the mechanism of male infertility caused by rapamycin and examined whether withdrawal of rapamycin could recover the number of sperm in rats. Male Sprague-Dawley rats (n=100) were divided randomly into 5 groups: 3 rapamycin-treated groups (2, 4 and 6 mg/kg) and 2 control groups [Blank and dimethyl sulfoxide (DMSO)]. Organ coefficients of the testes, number of sperm and hematoxylin-eosin staining analyses demonstrated that rapamycin treatment markedly damaged the structure of the seminiferous tubule and reduced the number of sperm. Immunohistochemistry of mechanistic target of rapamycin (mTOR) and Ki67 in testes tissue, and western blotting of phosphorylated-p70S6K and p70S6K, supported the hypothesis that rapamycin causes sperm reduction through inhibiting proliferation of spermatogonia. Unfortunately, 24 weeks after cessation of rapamycin treatment, only the number of sperm in 2 mg/kg group was restored back to the normal level. In addition, to the best of our knowledge, the present study was the first to demonstrate that low doses rapamycin leads to activation of autophagy in rat testes. This may be a self-protective mechanism of the cell in response to external stress. Thus, spermatogenesis can be recovered in the testes from rats in the low dose group. High doses of rapamycin resulted in excessive consumption of autophagy proteins, and the damage could not be compensated. In addition, it was revealed that cell apoptosis increased after treatment with rapamycin. In conclusion, the present study demonstrated that rapamycin inhibits spermatogenesis through suppressing phosphorylation of p70S6K and changing the autophagy status, ultimately reducing the number of sperm. These findings provide important guidance for the clinical application of rapamycin.
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Hwang HY, Cho SM, Kwon HJ. Approaches for discovering novel bioactive small molecules targeting autophagy. Expert Opin Drug Discov 2017; 12:909-923. [PMID: 28758515 DOI: 10.1080/17460441.2017.1349751] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
INTRODUCTION In recent years, development of novel bioactive small molecules targeting autophagy has been implicated for autophagy-related disease treatment. Screening new small molecules regulating autophagy allows for the discovery of novel autophagy machinery and therapeutic agents. Areas covered: Two major screening methods for novel autophagy modulators are introduced in this review, namely target based screening and phenotype based screening. With increasing attention focused on chemical compound libraries, coupled with the development of new assay systems, this review attempts to provide an efficient strategy to explore autophagy biology and discover small molecules for the treatment of autophagy-related diseases. Expert opinion: Adopting an appropriate autophagy screening strategy is important for developing small molecules capable of treating neurodegenerative diseases and cancers. Phenotype based screening and target based screening were both used for developing effective small molecules. However, each of these methods has many pros and cons. An efficient approach is suggested to screen for novel lead compounds targeting autophagy, which could provide new hits with better efficiency and rapidity.
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Affiliation(s)
- Hui-Yun Hwang
- a Chemical Genomics Global Research Laboratory, Department of Biotechnology, College of Life Science and Biotechnology , Yonsei University , Seoul , Republic of Korea
| | - Sung Min Cho
- a Chemical Genomics Global Research Laboratory, Department of Biotechnology, College of Life Science and Biotechnology , Yonsei University , Seoul , Republic of Korea
| | - Ho Jeong Kwon
- a Chemical Genomics Global Research Laboratory, Department of Biotechnology, College of Life Science and Biotechnology , Yonsei University , Seoul , Republic of Korea
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Praslicka B, Harmson JS, Kim J, Rangaraj VR, Ooi A, Gissendanner CR. BINDING SITE ANALYSIS OF THE CAENORHABDITIS ELEGANS NR4A NUCLEAR RECEPTOR NHR-6 DURING DEVELOPMENT. NUCLEAR RECEPTOR RESEARCH 2017; 4. [PMID: 29026837 DOI: 10.11131/2017/101288] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Members of the NR4A subfamily of nuclear receptors make up a highly conserved, functionally diverse group of transcription factors implicated in a multitude of cellular processes such as proliferation, differentiation, apoptosis, metabolism and DNA repair. The gene nhr-6, which encodes the sole C. elegans NR4A nuclear receptor homolog, has a critical role in organogenesis and regulates the development of the spermatheca organ system. Our previous work revealed that nhr-6 is required for spermatheca cell divisions in late L3 and early L4 and spermatheca cell differentiation during the mid L4 stage. Here, we utilized chromatin immunoprecipitation followed by next-generation sequencing (ChIP-seq) to identify NHR-6 binding sites during both the late L3/early L4 and mid L4 developmental stages. Our results revealed 30,745 enriched binding sites for NHR-6, ~70% of which were within 3 kb upstream of a gene transcription start site. Binding sites for a cohort of candidate target genes with probable functions in spermatheca organogenesis were validated through qPCR. Reproductive and spermatheca phenotypes were also evaluated for these genes following a loss-of-function RNAi screen which revealed several genes with critical functions during spermatheca organogenesis. Our results uncovered a complex nuclear receptor regulatory network whereby NHR-6 regulates multiple cellular processes during spermatheca organogenesis.
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Affiliation(s)
- Brandon Praslicka
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, and Biology Program, School of Science, University of Louisiana Monroe, Monroe, LA, USA 71209
| | - Jeremy S Harmson
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, and Biology Program, School of Science, University of Louisiana Monroe, Monroe, LA, USA 71209
| | - Joohyun Kim
- Center for Computation and Technology, Louisiana State University, Baton Rouge, LA, USA 70803
| | - Vittobai Rashika Rangaraj
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, and Biology Program, School of Science, University of Louisiana Monroe, Monroe, LA, USA 71209
| | - Aikseng Ooi
- Department of Pharmacology & Toxicology, College of Pharmacy, University of Arizona, Tucson, AZ, USA 85721
| | - Chris R Gissendanner
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, and Biology Program, School of Science, University of Louisiana Monroe, Monroe, LA, USA 71209
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Salton GD, Laurino CCFC, Mega NO, Delgado-Cañedo A, Setterblad N, Carmagnat M, Xavier RM, Cirne-Lima E, Lenz G, Henriques JAP, Laurino JP. Deletion of eIF2β lysine stretches creates a dominant negative that affects the translation and proliferation in human cell line: A tool for arresting the cell growth. Cancer Biol Ther 2017; 18:560-570. [PMID: 28692326 DOI: 10.1080/15384047.2017.1345383] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Eukaryote initiation factor 2 subunit β (eIF2β) plays a crucial role in regulation protein synthesis, which mediates the interaction of eIF2 with mRNA. eIF2β contains evolutionarily conserved polylysine stretches in amino-terminal region and a zinc finger motif in the carboxy-terminus. METHODS The gene eIF2β was cloned under tetracycline transcription control and the polylysine stretches were deleted by site-directed mutagenesis (eIF2βΔ3K). The plasmid was transfected into HEK 293 TetR cells. These cells were analyzed for their proliferative and translation capacities as well as cell death rate. Experiments were performed using gene reporter assays, western blotting, flow cytometry, cell sorting, cell proliferation assays and confocal immunofluorescence. RESULTS eIF2βΔ3K affected negatively the protein synthesis, cell proliferation and cell survival causing G2 cell cycle arrest and increased cell death, acting in a negative dominant manner against the native protein. Polylysine stretches are also essential for eIF2β translocated from the cytoplasm to the nucleus, accumulating in the nucleolus and eIF2βΔ3K did not make this translocation. DISCUSSION eIF2β is involved in the protein synthesis process and should act in nuclear processes as well. eIF2βΔ3K reduces cell proliferation and causes cell death. Since translation control is essential for normal cell function and survival, the development of drugs or molecules that inhibit translation has become of great interest in the scenario of proliferative disorders. In conclusion, our results suggest the dominant negative eIF2βΔ3K as a therapeutic strategy for the treatment of proliferative disorders and that eIF2β polylysine stretch domains are promising targets for this.
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Affiliation(s)
- Gabrielle Dias Salton
- a Post-Graduation Program in Cellular and Molecular Biology, Molecular Radiobiology Laboratory, Biotechnology Center , Universidade Federal do Rio Grande do Sul , Porto Alegre (RS) , Brazil , Cryobiology Unit and Umbilical Cord Blood Bank, Hemotherapy Service , Hospital de Clínicas de Porto Alegre , Porto Alegre (RS) , Brazil
| | - Claudia Cilene Fernandes Correia Laurino
- b Molecular Biology for Auto-immune and Infectious Diseases Laboratory, Experimental Research Center, Hospital de Clínicas de Porto Alegre , Universidade Federal do Rio Grande do Sul , Porto Alegre (RS) , Brazil . Embriology and Cellular Differentiation Laboratory, Experimental Research Center, Hospital de Clínicas de Porto Alegre; Faculdade de Veterinária , Universidade Federal do Rio Grande do Sul , Porto Alegre (RS) , Brazil . Faculdade Nossa Senhora de Fátima , Caxias do Sul (RS) , Brazil . Instituto Brasileiro de Saúde , Porto Alegre (RS) , Brazil
| | - Nicolás Oliveira Mega
- c Animal Biology Post-Graduation Program , Universidade Federal do Rio Grande do Sul , Porto Alegre (RS) , Brazil
| | - Andrés Delgado-Cañedo
- d Biotechnology Research Center for Interdisciplinary Research , Universidade Federal do Pampa , São Gabriel (RS) , Brazil
| | - Niclas Setterblad
- e Imaging, Cell Selection and Genomics Platform , Institut Universitaire d'Hématologie, Hôpital Saint-Louis , Paris , France
| | - Maryvonnick Carmagnat
- f Immunology and Histocompatibility Laboratory AP-HP , INSERM UMRS 940, Institut Universitaire d'Hématologie , Paris , France
| | - Ricardo Machado Xavier
- g Molecular Biology for Auto-immune and Infectious Diseases Laboratory, Experimental Research Center, Hospital de Clínicas de Porto Alegre , Universidade Federal do Rio Grande do Sul , Porto Alegre (RS) , Brazil
| | - Elizabeth Cirne-Lima
- h Embriology and Cellular Differentiation Laboratory, Experimental Research Center, Hospital de Clínicas de Porto Alegre; Faculdade de Veterinária , Universidade Federal do Rio Grande do Sul , Porto Alegre (RS) , Brazil
| | - Guido Lenz
- i Cell Signaling Laboratory, Biophysics Department, Biotechnology Center and Post-Graduation Program in Cellular and Molecular Biology , Universidade Federal do Rio Grande do Sul , Porto Alegre (RS) , Brazil
| | - João Antonio Pêgas Henriques
- j Molecular Radiobiology Laboratory, Biotechnology Center and Post-Graduation Program in Cellular and Molecular Biology , Universidade Federal do Rio Grande do Sul , Porto Alegre (RS) ; Biotechnology Institute , Universidade de Caxias do Sul , Caxias do Sul (RS) , Brazil
| | - Jomar Pereira Laurino
- k Biotechnology Institute , Universidade de Caxias do Sul, Caxias do Sul (RS) and Instituto Brasileiro de Saúde , Porto Alegre (RS) , Brazil
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Figueiredo VC, Markworth JF, Cameron-Smith D. Considerations on mTOR regulation at serine 2448: implications for muscle metabolism studies. Cell Mol Life Sci 2017; 74:2537-2545. [PMID: 28220207 PMCID: PMC11107628 DOI: 10.1007/s00018-017-2481-5] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 01/27/2017] [Accepted: 01/30/2017] [Indexed: 02/03/2023]
Abstract
The mammalian target of rapamycin (mTOR) complex exerts a pivotal role in protein anabolism and cell growth. Despite its importance, few studies adequately address the complexity of phosphorylation of the mTOR protein itself to enable conclusions to be drawn on the extent of kinase activation following this event. In particular, a large number of studies in the skeletal muscle biology field have measured Serine 2448 (Ser2448) phosphorylation as a proxy of mTOR kinase activity. However, the evidence to be described is that Ser2448 is not a measure of mTOR kinase activity nor is a target of AKT activity and instead has inhibitory effects on the kinase that is targeted by the downstream effector p70S6K in a negative feedback loop mechanism, which is evident when revisiting muscle research studies. It is proposed that this residue modification acts as a fine-tuning mechanism that has been gained during vertebrate evolution. In conclusion, it is recommended that Ser2448 is an inadequate measure and that preferential analysis of mTORC1 activation should focus on the downstream and effector proteins, including p70S6K and 4E-BP1, along mTOR protein partners that bind to mTOR protein to form the active complexes 1 and 2.
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Affiliation(s)
- Vandré Casagrande Figueiredo
- The Liggins Institute, University of Auckland, 85 Park Road, Grafton, Private Bag 92019, Auckland, 1023, New Zealand
| | - James F Markworth
- The Liggins Institute, University of Auckland, 85 Park Road, Grafton, Private Bag 92019, Auckland, 1023, New Zealand
| | - David Cameron-Smith
- The Liggins Institute, University of Auckland, 85 Park Road, Grafton, Private Bag 92019, Auckland, 1023, New Zealand.
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Liu Y, Wang X, Jia Y, Liu Y. Effects of bufalin on the mTOR/p70S6K pathway and apoptosis in esophageal squamous cell carcinoma in nude mice. Int J Mol Med 2017; 40:357-366. [PMID: 28656204 PMCID: PMC5504976 DOI: 10.3892/ijmm.2017.3039] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 06/15/2017] [Indexed: 12/20/2022] Open
Abstract
The aim of this study was to investigate the effects of bufalin on the mammalian target of rapamycin (mTOR/p70S6 kinase (p70S6K) signaling pathway and cell apoptosis in orthotopically transplanted tumors in nude mice. The mice were inoculated with human esophageal squamous cell carcinoma (ESCC) ECA109 cells in order to establish a model of orthotopicall transplanted ESCC tumors. The mice are administered low, medium and high doses of bufalin (0.5, 1.0 and 1.5 mg/kg) or rapamycin, or a combination of both. After the tumors were removed, the mRNA expression levels of mTOR, p70S6K, eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1), cellular inhibitor of apoptosis protein 1 (cIAP1) and caspase-3 were detected by RT-PCR. In addition, we performed western blot analysis and immunohistochemical analysis to determine the protein expression of mTOR, p70S6K, 4EBP1, cIAP1, active caspase-3, Bcl-2 and Bad in the tumor tissue. The results revealed that bufalin exerted a significant anti-tumor effect in the nude mice with ESCC orthotopically transplanted tumors. This was shown by the decrease in the expression of mTOR, p70S6K and 4EBP1, which suggested that bufalin may possibly be used to inhibit tumor growth via the inhibition of the activation of p70S6K and 4EBP1. We also found that bufalin decreased the expression of cIAP1 and Bcl-2, and increased that of active caspase-3 and Bad, thus indicating that bufalin promoted apoptosis. Thus, our findings suggest that bufalin promotes tumor cell apoptosis, and this may be one of the important anti-tumor mechanisms of action of bufalin.
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Affiliation(s)
- Yao Liu
- Department of Pathology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Xu Wang
- Department of Pathology, The First Central Hospital of Baoding, Baoding, Hebei 071000, P.R. China
| | - Ying Jia
- Department of Pathology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Yueping Liu
- Department of Pathology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
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Sun J, Ren D. IER3IP1 deficiency leads to increased β-cell death and decreased β-cell proliferation. Oncotarget 2017; 8:56768-56779. [PMID: 28915629 PMCID: PMC5593600 DOI: 10.18632/oncotarget.18179] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 04/27/2017] [Indexed: 12/19/2022] Open
Abstract
Mutations in the gene for Immediate Early Response 3 Interacting Protein 1 (IER3IP1) cause permanent neonatal diabetes mellitus in human. The mechanisms involved have not been determined and the role of IER3IP1 in β-cell survival has not been characterized. In order to determine if there is a molecular link between IER3IP1 deficiency and β-cell survival and proliferation, we knocked down Ier3ip1 gene expression in mouse MIN6 insulinoma cells. IER3IP1 suppression induced apoptotic cell death which was associated with an increase in Bim and a decrease in Bcl-xL. Knockdown of Bim reduced apoptotic cell death in MIN6 cells induced by IER3IP1 suppression. Overexpression of the anti-apoptotic molecule Bcl-xL prevents cell death induced by IER3IP1 suppression. Moreover, IER3IP1 also regulates activation of the unfolded protein response (UPR). IER3IP1 suppression impairs the Inositol Requiring 1 (IRE1) and PKR-like ER kinase (PERK) arms of UPR. The cell proliferation of MIN6 cells was also decreased in IER3IP1 deficient cells. These results suggest that IER3IP1 suppression induces an increase in cell death and a decrease in cell proliferation in MIN6 cells, which may be the mechanism that mutations in IER3IP1 lead to diabetes.
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Affiliation(s)
- Juan Sun
- Department of Medicine, The University of Chicago, Chicago, IL 60637, USA
| | - Decheng Ren
- Department of Medicine, The University of Chicago, Chicago, IL 60637, USA
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Upstream and Downstream Co-inhibition of Mitogen-Activated Protein Kinase and PI3K/Akt/mTOR Pathways in Pancreatic Ductal Adenocarcinoma. Neoplasia 2017; 18:425-35. [PMID: 27435925 PMCID: PMC5022074 DOI: 10.1016/j.neo.2016.06.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 05/29/2016] [Accepted: 06/03/2016] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Extensive cross talk exists between PI3K/Akt/mTOR and mitogen-activated protein kinase (MAPK) pathways, and both are upregulated in pancreatic ductal adenocarcinoma (PDAC). Our previous study suggested that epidermal growth factor receptor inhibitor erlotinib which acts upstream of these pathways acts synergistically with PI3K inhibitors in PDAC. Horizontal combined blockade upstream and downstream of these two pathways is therefore explored. METHODS Erlotinib paired with PI3K inhibitor (BYL719) was tested against erlotinib plus dual PI3K/mTOR inhibitor BEZ-235, and MEK inhibitor (PD98059) plus BEZ235, on five primary PDAC cell lines and on two pairs of parent and erlotinib-resistant (ER) cell lines. A range of in vitro assays including cell proliferation, Western blotting, migration, clonogenic, cell cycle, and apopotic assays was used to test for the efficacy of combined blockade. RESULTS Dual downstream blockade of the MAPK and PAM pathways was more effective in attenuating downstream molecular signals. Synergy was demonstrated for erlotinib and BEZ235 and for PD-98059 and BEZ-235. This resulted in a trend of increased growth cell cycle arrest, apoptosis, cell proliferation, and colony and migration suppression. This combination showed more efficacy in cell lines with acquired resistance to erlotinib. CONCLUSIONS The additional mTOR blockade provided by BEZ235 in combined blockade resulted in increased anticancer effect. The hypersensitivity of ER cell lines to additional mTOR blockade suggested PAM pathway oncogenic dependence via mTOR. Dual downstream combined blockade of MAPK and PAM pathways with MEK and PI3K/mTOR inhibitor appeared most effective and represents an attractive therapeutic strategy against pancreatic cancer and its associated drug resistance.
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Smithson LJ, Gutmann DH. Proteomic analysis reveals GIT1 as a novel mTOR complex component critical for mediating astrocyte survival. Genes Dev 2017; 30:1383-8. [PMID: 27340174 PMCID: PMC4926861 DOI: 10.1101/gad.279661.116] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 05/16/2016] [Indexed: 11/24/2022]
Abstract
Smithson and Gutmann reveal that mTOR complex molecular composition varies in different somatic tissues. In astrocytes and neural stem cells, they identified G-protein-coupled receptor kinase interactor protein 1 (GIT1) as a novel mTOR-binding protein, creating a unique mTOR complex lacking Raptor and Rictor. GIT1 binding to mTOR was essential for mTOR-mediated astrocyte survival. As a critical regulator of cell growth, the mechanistic target of rapamycin (mTOR) protein operates as part of two molecularly and functionally distinct complexes. Herein, we demonstrate that mTOR complex molecular composition varies in different somatic tissues. In astrocytes and neural stem cells, we identified G-protein-coupled receptor kinase-interacting protein 1 (GIT1) as a novel mTOR-binding protein, creating a unique mTOR complex lacking Raptor and Rictor. Moreover, GIT1 binding to mTOR is regulated by AKT activation and is essential for mTOR-mediated astrocyte survival. Together, these data reveal that mTOR complex function is partly dictated by its molecuflar composition in different cell types.
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Affiliation(s)
- Laura J Smithson
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - David H Gutmann
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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mTORC1 promotes proliferation of immature Schwann cells and myelin growth of differentiated Schwann cells. Proc Natl Acad Sci U S A 2017; 114:E4261-E4270. [PMID: 28484008 PMCID: PMC5448230 DOI: 10.1073/pnas.1620761114] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The myelination of axons in peripheral nerves requires precisely coordinated proliferation and differentiation of Schwann cells (SCs). We found that the activity of the mechanistic target of rapamycin complex 1 (mTORC1), a key signaling hub for the regulation of cellular growth and proliferation, is progressively extinguished as SCs differentiate during nerve development. To study the effects of different levels of sustained mTORC1 hyperactivity in the SC lineage, we disrupted negative regulators of mTORC1, including TSC2 or TSC1, in developing SCs of mutant mice. Surprisingly, the phenotypes ranged from arrested myelination in nerve development to focal hypermyelination in adulthood, depending on the level and timing of mTORC1 hyperactivity. For example, mice lacking TSC2 in developing SCs displayed hyperproliferation of undifferentiated SCs incompatible with normal myelination. However, these defects and myelination could be rescued by pharmacological mTORC1 inhibition. The subsequent reconstitution of SC mTORC1 hyperactivity in adult animals resulted in focal hypermyelination. Together our data suggest a model in which high mTORC1 activity promotes proliferation of immature SCs and antagonizes SC differentiation during nerve development. Down-regulation of mTORC1 activity is required for terminal SC differentiation and subsequent initiation of myelination. In distinction to this developmental role, excessive SC mTORC1 activity stimulates myelin growth, even overgrowth, in adulthood. Thus, our work delineates two distinct functions of mTORC1 in the SC lineage essential for proper nerve development and myelination. Moreover, our studies show that SCs retain their plasticity to myelinate and remodel myelin via mTORC1 throughout life.
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Shao Y, Wolf PG, Guo S, Guo Y, Gaskins HR, Zhang B. Zinc enhances intestinal epithelial barrier function through the PI3K/AKT/mTOR signaling pathway in Caco-2 cells. J Nutr Biochem 2017; 43:18-26. [DOI: 10.1016/j.jnutbio.2017.01.013] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 01/17/2017] [Accepted: 01/19/2017] [Indexed: 12/24/2022]
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Poquérusse J, Luikart BW. A Neurodevelopmental Perspective for Autism-Associated Gene Function. OBM NEUROBIOLOGY 2017; 1:004. [PMID: 35445171 PMCID: PMC9017685 DOI: 10.21926/obm.neurobiol.1702004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Large-scale genetic sequencing studies have identified a wealth of genes in which mutations are associated with autism spectrum disorder (ASD). Understanding the biological function of these genes sheds light onto the neurodevelopmental basis of ASD. To this end, we defined functional categories representing brain development - (1) Cell Division and Survival, (2) Cell Migration and Differentiation, (3) Neuronal Morphological Elaboration, (4) Development and Regulation of Cellular Excitability, and (5) Synapse Formation and Function - and place 100 high confidence ASD-associated genes yielding at least 50 published PubMed articles into these categories based on keyword searches. We compare the categorization of ASD genes to genes associated with developmental delay (DD) and systematically review the published literature on the function of these genes. We find evidence that ASD-associated genes have important functions that span the neurodevelopmental continuum. Further, examining the temporal expression pattern of these genes using the BrainSpan Atlas of the Developing Human Brain supports their function across development. Thus, our analyses and review of literature on ASD gene function support a model whereby differences in brain development - from very early stages of macroarchitectural patterning to late stages of activity-dependent sculpting of synaptic connectivity - may lead to ASD. It will be important to keep investigating potential points of mechanistic convergence which could explain a common pathophysiological basis of ASD behind this disparate array of genes.
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Xin L, Xu B, Ma L, Hou Q, Ye M, Meng S, Ding X, Ge W. Proteomics study reveals that the dysregulation of focal adhesion and ribosome contribute to early pregnancy loss. Proteomics Clin Appl 2017; 10:554-63. [PMID: 26947931 PMCID: PMC5084743 DOI: 10.1002/prca.201500136] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 01/10/2016] [Accepted: 02/29/2016] [Indexed: 12/30/2022]
Abstract
Purpose Early pregnancy loss (EPL) affects 50–70% pregnant women in first trimester. The precise molecular mechanisms underlying EPL are far from being fully understood. Therefore, we aim to identify the molecular signaling pathways relating to EPL. Experimental design We performed proteomics and bioinformatics analysis of the placental villi in women who have undergone EPL and in normal pregnant women. The proteomics data were validated by Western blot analysis. Results We identified a total of 5952 proteins in placental villi, of which 588 proteins were differentially expressed in the EPL women. Bioinformatics analysis revealed that these differentially expressed proteins participated in a variety of signaling pathways, including the focal adhesion pathway and ribosome pathway. Moreover, results of the Western blot confirmed that Desmin, Lamin A/C, MMP‐9, and histone H4 were upregulated in EPL and the Lamin C/ Lamin A ratio decreased obviously in EPL. These proteins could be associated with the pathophysiology of EPL. The data have been deposited to the ProteomeXchange with identifier PXD002391. Conclusion and clinical relevance Our study demonstrated that the focal adhesion pathway and ribosome pathway are involved in EPL, and these findings might contribute to unveil the pathophysiology of EPL.
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Affiliation(s)
- Lingli Xin
- Department of Obstetrics and Gynecology, the General Hospital of the PLA Rocket Force, Beijing, China
| | - Benhong Xu
- National Key Laboratory of Medical Molecular Biology, Department of Immunology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Beijing, China
| | - Li Ma
- Department of Obstetrics and Gynecology, the General Hospital of the PLA Rocket Force, Beijing, China
| | - Qingxiang Hou
- Department of Obstetrics and Gynecology, the General Hospital of the PLA Rocket Force, Beijing, China
| | - Mei Ye
- Department of Obstetrics and Gynecology, the General Hospital of the PLA Rocket Force, Beijing, China
| | - Shu Meng
- National Key Laboratory of Medical Molecular Biology, Department of Immunology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Beijing, China
| | - Xiaoping Ding
- Department of Obstetrics and Gynecology, the General Hospital of the PLA Rocket Force, Beijing, China
| | - Wei Ge
- National Key Laboratory of Medical Molecular Biology, Department of Immunology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Beijing, China
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Kuczkowski A, Brinkkoetter PT. Metabolism and homeostasis in the kidney: metabolic regulation through insulin signaling in the kidney. Cell Tissue Res 2017; 369:199-210. [DOI: 10.1007/s00441-017-2619-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 03/22/2017] [Indexed: 02/07/2023]
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Elahi F, Lee H, Lee J, Lee ST, Park CK, Hyun SH, Lee E. Effect of rapamycin treatment during post-activation and/or in vitro culture on embryonic development after parthenogenesis and in vitro fertilization in pigs. Reprod Domest Anim 2017; 52:741-748. [PMID: 28397300 DOI: 10.1111/rda.12974] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 02/26/2017] [Indexed: 11/30/2022]
Abstract
This study investigated the effects of early induction of autophagy on embryonic development in pigs. For this, oocytes or embryos were treated with an autophagy inducer, rapamycin (RP), during post-activation (Pa), in vitro fertilization (IVF) and/or in vitro culture (IVC). When parthenogenesis (PA) embryos were untreated (control) or treated with various concentrations of RP for 4 hr during Pa, 100 nm RP showed a higher blastocyst formation (48.8 ± 2.7%) than the control (34.6 ± 3.0%). When PA embryos were treated during the first 24 hr of IVC, blastocyst formation was increased (p < .05) by 1 and 10 nm RP (61.9 ± 3.0 and 59.6 ± 3.0%, respectively) compared to the control (43.2 ± 1.8%) and 100 nm RP (47.8 ± 3.2%), with a higher embryo cleavage in response to 10 nm RP (87.3 ± 2.4%) than the control (74.1 ± 3.2%). RP treatment during IVC and Pa + IVC showed increased blastocyst formation (44.7 ± 2.5 and 44.1 ± 2.0%, respectively) compared to the control (33.2 ± 2.0%). In addition, RP treatment during Pa and/or IVC increased glutathione content and inversely reduced reactive oxygen species. In IVF, RP treatment for 6 hr during IVF significantly increased embryonic development (34.0 ± 2.6%) compared to the control (24.8 ± 1.6%), but treatment during IVC for 24 hr with RP did not (23.0 ± 3.8%). Autophagy was significantly increased in PA oocytes by the RP treatment during Pa but not altered by the treatment during the first 24 hr of IVC. Overall, RP treatment positively regulated the pre-implantation development of pig embryos, probably by regulating cellular redox state and stimulating autophagy.
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Affiliation(s)
- F Elahi
- Laboratory of Theriogenology, College of Veterinary Medicine, Kangwon National University, Chuncheon, Korea
| | - H Lee
- Laboratory of Theriogenology, College of Veterinary Medicine, Kangwon National University, Chuncheon, Korea
| | - J Lee
- Laboratory of Theriogenology, College of Veterinary Medicine, Kangwon National University, Chuncheon, Korea.,Institute of Veterinary Science, Kangwon National University, Chuncheon, Korea
| | - S T Lee
- Division of Applied Animal Science, College of Animal Life Science, Kangwon National University, Chuncheon, Korea
| | - C K Park
- Division of Applied Animal Science, College of Animal Life Science, Kangwon National University, Chuncheon, Korea
| | - S-H Hyun
- Laboratory of Veterinary Embryology and Biotechnology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Korea
| | - E Lee
- Laboratory of Theriogenology, College of Veterinary Medicine, Kangwon National University, Chuncheon, Korea.,Institute of Veterinary Science, Kangwon National University, Chuncheon, Korea
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