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Gao J, You T, Liu J, Yang L, Liu Y, Wang Y. TIPRL, a Potential Double-edge Molecule to be Targeted and Re-targeted Toward Cancer. Cell Biochem Biophys 2024:10.1007/s12013-024-01334-5. [PMID: 38888871 DOI: 10.1007/s12013-024-01334-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2024] [Indexed: 06/20/2024]
Abstract
The target of rapamycin (TOR) proteins exhibits phylogenetic conservation across various species, ranging from yeast to humans, and are classified as members of the phosphatidylinositol kinase (PIK)-related kinase family. Multiple serine/threonine (Ser/Thr) protein phosphatases (PP)2A, PP4, and PP6, have been recognized as constituents of the TOR signaling pathway in mammalian cells. The protein known as TOR signaling pathway regulator-like (TIPRL) functions as a regulatory agent by impeding the activity of the catalytic subunits of PP2A. Various cellular contexts have been postulated for TIPRL, encompassing the regulation of mechanistic target of rapamycin (mTOR) signaling, inhibition of apoptosis and biogenesis, and recycling of PP2A. According to reports, there has been an observed increase in TIPRL levels in several types of carcinomas, such as non-small-cell lung carcinoma (NSCLC) and hepatocellular carcinomas (HCC). This review aims to comprehensively examine the significance of the Tor pathway in regulating apoptosis and proliferation of cancer cells, with a specific focus on the role of TOR signaling and TIPRL in cancer.
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Affiliation(s)
- Jie Gao
- Department of Pharmacy, Zibo Central Hospital, Zibo, 255036, China
| | - Tiantian You
- Department of Pharmacy, Zibo Central Hospital, Zibo, 255036, China
| | - Jiao Liu
- Department of Pharmacy, Zibo Central Hospital, Zibo, 255036, China
| | - Lili Yang
- Department of Pharmacy, Zibo Central Hospital, Zibo, 255036, China
| | - Yan Liu
- Department of Pharmacy, Zibo Central Hospital, Zibo, 255036, China
| | - Yanyan Wang
- Department of Pharmacy, Zibo Central Hospital, Zibo, 255036, China.
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2
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Zhang Y, Sun J, Li M, Hou L, Wang Z, Dong H, Xu W, Jiang R, Geng Y, Guan C, Zhu Z, Wang H, Gong Q, Zhang G. Identification and validation of a disulfidptosis-related genes prognostic signature in lung adenocarcinoma. Heliyon 2024; 10:e23502. [PMID: 38223725 PMCID: PMC10784160 DOI: 10.1016/j.heliyon.2023.e23502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 10/26/2023] [Accepted: 12/05/2023] [Indexed: 01/16/2024] Open
Abstract
Disulfidptosis, a newly revealed form of cell death, regulated by numerous genes that has been recently identified. The exact role of disulfidptosis in lung adenocarcinoma (LUAD) still uncertain. Objective of this study was to explore potential prognostic markers among disulfidptosis genes in LUAD. By combining transcriptomic information from Gene Expression Omnibus databases and The Cancer Genome Atlas, we identified differentially expressed and prognostic disulfidptosis genes. By conducting least absolute shrinkage and selection operator with multivariate Cox regression, four disulfidptosis genes were selected to create the prognostic signature. The implementation of the signature separated the training and validation cohorts into groups with high- and low-risk. Subsequently, the model was verified by conducting an independent analysis of receiver operating characteristic (ROC) curves. Further comparisons were made between the two risk-divided groups with regards the tumor microenvironment, immune cell infiltration, immunotherapy response, and drug sensitivity. The signature was constructed using four disulfidptosis-related genes: SLC7A11, SLC3A2, NCKAP1, and GYS1. According to ROC curves, the signature was effective for predicting LUAD prognosis. In addition, the prognostic signature correlated with sensitivity to chemotherapeutic agents and the efficacy of immunotherapy in LUAD. Finally, through external validation, we showed that NCKAP1 are correlated with tumor migration, proliferation, and invasion of LUAD cells. GYS1 affects immune cell, especially M2 macrophage infiltration in the tumor microenvironment. The disulfidptosis four-gene model can reliably predict the prognosis of patients diagnosed with LUAD, thereby providing valuable information for clinical applications and immunotherapy.
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Affiliation(s)
- Yanpeng Zhang
- Department of Thoracic Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Jingyang Sun
- The First Clinical Medical College of Gansu University of Chinese Medicine (Gansu Provincial Hospital), Lanzhou, China
- Department of Thoracic Surgery, Gansu Central Hospital, Lanzhou, China
| | - Meng Li
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Xi'an Jiao Tong University, Xi'an, China
| | - Liren Hou
- Department of Thoracic Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Zhiyu Wang
- Department of Thoracic Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Huanhuan Dong
- Department of Thoracic Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Wenjun Xu
- Department of Thoracic Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Rongxuan Jiang
- Department of Thoracic Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Yuhan Geng
- Department of Thoracic Surgery, Gansu Central Hospital, Lanzhou, China
| | - Chungen Guan
- Department of Thoracic Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
- Department of Thoracic Surgery, Gansu Central Hospital, Lanzhou, China
| | - Zijiang Zhu
- Department of Thoracic Surgery, Gansu Central Hospital, Lanzhou, China
| | - Hongyi Wang
- Department of Thoracic Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Qiuyu Gong
- Department of Thoracic Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Guangjian Zhang
- Department of Thoracic Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
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3
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Oh PS, Kim EM, Boud F, Lim S, Jeong HJ. Blue Light Inhibits Proliferation of Metastatic Cancer Cells by Regulating Translational Initiation: A Synergistic Property with Anticancer Drugs. Photochem Photobiol 2023; 99:1438-1447. [PMID: 36732943 DOI: 10.1111/php.13789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 01/31/2023] [Indexed: 02/04/2023]
Abstract
The aim of this study was to examine the inhibitory effect of blue light (BL) on the proliferation of metastatic cancer cells and synergistic properties with chemo-drugs. BL significantly inhibited the proliferation of B cell lymphoma (A20 and RAMOS) cells in a dose-dependent manner. Anti-proliferative effect of BL irradiation was identified to be associated with the inhibition of proliferating-cell nuclear antigen expression and cell cycle by decreasing S-phase cells. Consistent with its inhibitory effects, BL irradiation at 20 J/cm2 daily for 10 days inhibited metastasis of cancer cells which were distributed and invaded to other organs including bone marrow, liver, kidney, etc., and induced paraplegia, thereby leading to an increased survival rate of tumor-bearing mice. Anti-proliferative activity of BL was expanded in solid tumor cells including pancreatic carcinoma (Mia PaCa-2, PANC-1), lung carcinoma A549 and colorectal carcinoma HCT116 cells. Additionally, combination with chemo-drugs such as 5-FU and gemcitabine resulted in an increase in the anti-proliferative activity after BL irradiation accompanied by regulating mRNA translational process via inhibition of p70S6K, 4EBP-1 and eIF4E phosphorylation during cellular proliferation. These results indicate the anti-metastatic and photo-biogoverning abilities of BL irradiation as a potent therapeutic potential for repressing the progression of tumor cells.
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Affiliation(s)
- Phil-Sun Oh
- Department of Nuclear Medicine, Molecular Imaging & Therapeutic Medicine Research Center, Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonbuk National University Medical School and Hospital, Republic of Korea
| | - Eun-Mi Kim
- Department of Nuclear Medicine, Molecular Imaging & Therapeutic Medicine Research Center, Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonbuk National University Medical School and Hospital, Republic of Korea
| | - Fatima Boud
- Department of Nuclear Medicine, Molecular Imaging & Therapeutic Medicine Research Center, Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonbuk National University Medical School and Hospital, Republic of Korea
| | - SeokTae Lim
- Department of Nuclear Medicine, Molecular Imaging & Therapeutic Medicine Research Center, Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonbuk National University Medical School and Hospital, Republic of Korea
| | - Hwan-Jeong Jeong
- Department of Nuclear Medicine, Molecular Imaging & Therapeutic Medicine Research Center, Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonbuk National University Medical School and Hospital, Republic of Korea
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Effects of 1α,25-dihydroxyvitamin D3 and tacalcitol on cell signaling and anchorage-independent growth in T98G and U251 glioblastoma cells. Biochem Biophys Rep 2022; 31:101313. [PMID: 35935021 PMCID: PMC9352528 DOI: 10.1016/j.bbrep.2022.101313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 06/30/2022] [Accepted: 07/11/2022] [Indexed: 11/21/2022] Open
Abstract
The active hormonal form of vitamin D, 1α,25-dihydroxyvitamin D3, is reported to have 1000s of biological targets. The growth-suppressive properties of 1α,25-dihydroxyvitamin D3 and its synthetic analogs have attracted interest for the development of treatment and/or prevention of cancer. We examined effects of 1α,25-dihydroxyvitamin D3 and the vitamin D analog tacalcitol on signaling pathways and anchorage-independent growth in T98G and U251 glioblastoma cells. Assay of signaling proteins important for cellular growth indicated suppression of p70-S6 kinase levels by 1α,25-dihydroxyvitamin D3 and tacalcitol in T98G cells, whereas the levels of PLCγ, a target for phospholipid signaling, was slightly increased. Activation of STAT3, an important regulator of malignancy, was suppressed by 1α,25-dihydroxyvitamin D3 and tacalcitol in T98G and U251 cells. However, despite the close structural similarity of these compounds, suppression was stronger by tacalcitol (1α,24-dihydroxyvitamin D3), indicating that even minor modifications of a vitamin D analog can impact its effects on signaling. Experiments using soft agar colony formation assay in T98G and U251 cells revealed significant suppression by 1α,25-dihydroxyvitamin D3 and tacalcitol on anchorage-independent growth, a property for cancer invasion and metastasis known to correlate with tumorigenicity. These findings indicate that vitamin D and its analogs may be able to counteract the oncogenic transformation, invasion and metastatic potential of glioblastoma and prompt further study of these compounds in the development of improved therapy for brain cancer. Vitamin D and its analog tacalcitol affect signaling in glioblastoma cell lines. Suppression of the oncogenic STAT-3 is stronger by tacalcitol than by vitamin D. Tacalcitol and vitamin D inhibit anchorage-independent growth in T98G and U251 cells. Vitamin D analogs may be useful to combat oncogenicity and invasion of glioblastoma.
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Beyond controlling cell size: functional analyses of S6K in tumorigenesis. Cell Death Dis 2022; 13:646. [PMID: 35879299 PMCID: PMC9314331 DOI: 10.1038/s41419-022-05081-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 07/05/2022] [Accepted: 07/07/2022] [Indexed: 01/21/2023]
Abstract
As a substrate and major effector of the mammalian target of rapamycin complex 1 (mTORC1), the biological functions of ribosomal protein S6 kinase (S6K) have been canonically assigned for cell size control by facilitating mRNA transcription, splicing, and protein synthesis. However, accumulating evidence implies that diverse stimuli and upstream regulators modulate S6K kinase activity, leading to the activation of a plethora of downstream substrates for distinct pathobiological functions. Beyond controlling cell size, S6K simultaneously plays crucial roles in directing cell apoptosis, metabolism, and feedback regulation of its upstream signals. Thus, we comprehensively summarize the emerging upstream regulators, downstream substrates, mouse models, clinical relevance, and candidate inhibitors for S6K and shed light on S6K as a potential therapeutic target for cancers.
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Lai CC, Chen TJ, Chan TC, Li WS, He HL. Prognostic significance of OXR1 in urothelial carcinoma: low OXR1 expression is associated with worse survival. Future Oncol 2021; 17:4145-4156. [PMID: 34467778 DOI: 10.2217/fon-2021-0184] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Background: Bioinformatic analysis has revealed that OXR1 is significantly downregulated in muscle-invasive bladder cancer. Patients & methods: The expression of OXR1 in patients with urothelial carcinoma was evaluated by immunohistochemistry, including 340 cases with urothelial carcinoma in the upper urinary tract and 295 in the urinary bladder. Results: Low expression of OXR1 was significantly correlated with adverse pathological parameters including high primary tumor (pT) stage, high node stage, high histological grade, high mitotic activity and increased vascular or perineural invasion (all p < 0.05). Low expression of OXR1 independently predicted worse metastasis-free survival (p = 0.033) in urothelial carcinoma of the upper urinary tract and worse disease-specific survival (p = 0.022) and metastasis-free survival (p < 0.001) in urothelial carcinoma of the urinary bladder. Conclusion: Low expression of OXR1 is an adverse prognostic factor in urothelial carcinoma.
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Affiliation(s)
- Chien-Cheng Lai
- College of Medicine, Chang Gung University, Taoyuan 333323, Taiwan
| | - Tzu-Ju Chen
- Department of Pathology, Chi Mei Medical Center, Tainan 71004, Taiwan.,Department of Medical Technology, Chung Hwa University of Medical Technology, Tainan 71703, Taiwan.,Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804201, Taiwan
| | - Ti-Chun Chan
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804201, Taiwan.,National Institute of Cancer Research, National Health Research Institutes, Tainan 704016, Taiwan
| | - Wan-Shan Li
- Department of Pathology, Chi Mei Medical Center, Tainan 71004, Taiwan.,Department of Medical Technology, Chung Hwa University of Medical Technology, Tainan 71703, Taiwan.,Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804201, Taiwan
| | - Hong-Lin He
- Department of Pathology, Chi Mei Medical Center, Tainan 71004, Taiwan.,Department of Optometry, Chung Hwa University of Medical Technology, Tainan 71703, Taiwan.,Department of Pathology, E-DA Hospital & E-DA Cancer Hospital, I-Shou University, Kaohsiung 82445, Taiwan
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7
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Henao-Restrepo J, Caro-Urrego YA, Barrera-Arenas LM, Arango-Viana JC, Bermudez-Munoz M. Expression of activator proteins of SHH/GLI and PI3K/Akt/mTORC1 signaling pathways in human gliomas is associated with high grade tumors. Exp Mol Pathol 2021; 122:104673. [PMID: 34371011 DOI: 10.1016/j.yexmp.2021.104673] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 07/25/2021] [Accepted: 08/03/2021] [Indexed: 01/15/2023]
Abstract
Recent findings have demonstrated a synergic crosstalk between SHH/GLI and PI3K/Akt/mTORC1 signaling in glioblastoma progression cells in vitro and in tumors in mice, but it is not known if this also occurs in human gliomas. We then aimed to investigate the expression of key proteins of these pathways in different human gliomas. The expression of PTEN, phospho-Akt (Ser473), phospho-S6K1 (Thr389), SHH, GLI1, GLI2 and GLI3 was assessed by immunohistochemistry in gliomas and in control brain tissues. The pattern of expression of each protein was established according to glioma type, glioma grade and to cell type; the relative expression of each protein was used to perform statistical analyses. We found that the expression of proteins of both signaling pathways differs between normal brain and glioma tissues. For instance, normal astrocytes had a different protein expression pattern compared with reactive and tumoral astrocytes. Interestingly, we detected a recurrent pattern of expression of GLI3 in oligodendrocytes and of phospho-S6K1 in mitotic neoplastic cells. We also identified differences of cell signaling according to glioma type: oligodendrogliomas and ependymomas are related with the expression of SHH/GLI proteins. Finally, we detected that high grade gliomas statistically correlate with the expression of GLI1 and GLI2, and that GLI1, GLI2, phospho-Akt and phospho-S6K1 are more expressed in patients with less survival, suggesting that activation of these cell signaling influences glioma outcome and patient survival. In summary, our results show that proteins of PI3K/Akt/mTORC1 and SHH/GLI pathways are differentially expressed in human gliomas according to tumor type and grade, and suggest that the activation of these signaling networks is associated with glioma progression.
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Affiliation(s)
- Julián Henao-Restrepo
- Institute of Biology, Faculty of Exact and Natural Sciences, University of Antioquia, Calle 67 #53-108, 050010 Medellín, Colombia.
| | - Yudys Anggelly Caro-Urrego
- Department of Pathology, Faculty of Medicine, University of Antioquia, Cra. 51d #62-29, 050010 Medellín, Colombia
| | - Lina Marcela Barrera-Arenas
- Grupo de Investigaciones Biomédicas, Health Sciences Faculty, University Corporation Remington, Calle 51 #51-27, Medellín, Colombia.
| | - Juan Carlos Arango-Viana
- Department of Pathology, Faculty of Medicine, University of Antioquia, Cra. 51d #62-29, 050010 Medellín, Colombia.
| | - Maria Bermudez-Munoz
- Institute of Biology, Faculty of Exact and Natural Sciences, University of Antioquia, Calle 67 #53-108, 050010 Medellín, Colombia.
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8
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Bryant JP, Levy A, Heiss J, Banasavadi-Siddegowda YK. Review of PP2A Tumor Biology and Antitumor Effects of PP2A Inhibitor LB100 in the Nervous System. Cancers (Basel) 2021; 13:cancers13123087. [PMID: 34205611 PMCID: PMC8235527 DOI: 10.3390/cancers13123087] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 12/14/2022] Open
Abstract
Simple Summary Central and peripheral nervous system tumors represent a heterogenous group of neoplasms which often demonstrate resistance to treatment. Given that these tumors are often refractory to conventional therapy, novel pharmaceutical regimens are needed for successfully treating this pathology. One such therapeutic is the serine/threonine phosphatase inhibitor, LB100. LB100 is a water-soluble competitive protein phosphtase inhibitor that has demonstrated antitumor effects in preclinical and clinical trials. In this review, we aim to summarize current evidence demonstrating the efficacy of LB100 as an inhibitor of nervous system tumors. Furthermore, we review the involvement of the well-studied phosphatase, protein phosphatase 2A, in oncogenic cell signaling pathways, neurophysiology, and neurodevelopment. Abstract Protein phosphatase 2A (PP2A) is a ubiquitous serine/threonine phosphatase implicated in a wide variety of regulatory cellular functions. PP2A is abundant in the mammalian nervous system, and dysregulation of its cellular functions is associated with myriad neurodegenerative disorders. Additionally, PP2A has oncologic implications, recently garnering attention and emerging as a therapeutic target because of the antitumor effects of a potent PP2A inhibitor, LB100. LB100 abrogation of PP2A is believed to exert its inhibitory effects on tumor progression through cellular chemo- and radiosensitization to adjuvant agents. An updated and unifying review of PP2A biology and inhibition with LB100 as a therapeutic strategy for targeting cancers of the nervous system is needed, as other reviews have mainly covered broader applications of LB100. In this review, we discuss the role of PP2A in normal cells and tumor cells of the nervous system. Furthermore, we summarize current evidence regarding the therapeutic potential of LB100 for treating solid tumors of the nervous system.
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Affiliation(s)
- Jean-Paul Bryant
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA; (J.-P.B.); (J.H.)
| | - Adam Levy
- Miller School of Medicine, University of Miami, Miami, FL 33136, USA;
| | - John Heiss
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA; (J.-P.B.); (J.H.)
| | - Yeshavanth Kumar Banasavadi-Siddegowda
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA; (J.-P.B.); (J.H.)
- Correspondence: ; Tel.: +1-301-451-0970
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Yoon MS. Nanotechnology-Based Targeting of mTOR Signaling in Cancer. Int J Nanomedicine 2020; 15:5767-5781. [PMID: 32821100 PMCID: PMC7418174 DOI: 10.2147/ijn.s254574] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 05/13/2020] [Indexed: 12/20/2022] Open
Abstract
Mammalian target of rapamycin (mTOR) is a master regulator of cell growth and metabolism, which is activated in response to intra- and extracellular signals, including nutrients, growth factors, and cellular energy levels. The frequent dysregulation of mTOR signaling in cancer makes it an attractive therapeutic target, and several types of mTOR inhibitors have been developed. Nanoparticle-based mTOR modulators are predicted to target various cancers and deliver as well as release drugs in a controlled manner, resulting in enhanced bioavailability and reduced side effects. This mini-review is focused on the molecular mechanism of nanoparticle-based mTOR modulator action as well as the current development of mTOR inhibitors using nanoparticles. Understanding the biological function of nanoparticle-based mTOR modulators will contribute to the development of efficient nano-therapeutics for the treatment of cancers.
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Affiliation(s)
- Mee-Sup Yoon
- Department of Molecular Medicine, School of Medicine, Lee Gil Ya Cancer and Diabetes Institute, Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon 21999, Republic of Korea
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10
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Li SZ, Hu YY, Zhao JL, Zang J, Fei Z, Han H, Qin HY. Downregulation of FHL1 protein in glioma inhibits tumor growth through PI3K/AKT signaling. Oncol Lett 2020; 19:3781-3788. [PMID: 32382330 PMCID: PMC7202308 DOI: 10.3892/ol.2020.11476] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 01/27/2020] [Indexed: 01/29/2023] Open
Abstract
Human four-and-a-half LIM domains protein 1 (FHL1) is a member of the FHL protein family, which serves an important role in multiple cellular events by interacting with transcription factors using its cysteine-rich zinc finger motifs. A previous study indicated that FHL1 was downregulated in several types of human cancer and served a role as a tumor suppressive gene. The overexpression of FHL1 inhibited tumor cell proliferation. However, to the best of our knowledge, there is no evidence to confirm whether FHL1 affected glioma growth, and the molecular mechanisms through which FHL1 represses tumor development remain unclear. In the present study, the expression level of FHL1 was determined using immunohistochemical staining in 114 tumor specimens from patients with glioma. The results indicated that FHL1 expression was negatively associated with the pathological grade of gliomas. Furthermore, Kaplan-Meier survival curves demonstrated that the patients with an increased FHL1 expression exhibited a significantly longer survival time, suggesting that FHL1 may be a prognostic marker for glioma. The protein level of FHL1 was relatively increased in the U251 glioma cell line compared with that in the U87 cell line. Therefore, FHL1 was knocked down in U251 by siRNA and overexpressed in U87, and it was identified that FHL1 significantly decreased the activation of PI3K/AKT signaling by interacting with AKT. Further experiments verified that FHL1 inhibited the growth of gliomas in vivo by modulating PI3K/AKT signaling. In conclusion, the results of the present study demonstrated that FHL1 suppressed glioma development through PI3K/AKT signaling.
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Affiliation(s)
- San-Zhong Li
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Yi-Yang Hu
- Department of Medical Genetics and Developmental Biology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Jun-Long Zhao
- Department of Medical Genetics and Developmental Biology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China.,Department of Biochemistry and Molecular Biology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Jian Zang
- Department of Medical Genetics and Developmental Biology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China.,Department of Radiation Oncology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Zhou Fei
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Hua Han
- Department of Medical Genetics and Developmental Biology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China.,Department of Biochemistry and Molecular Biology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Hong-Yan Qin
- Department of Medical Genetics and Developmental Biology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
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11
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Athamneh K, Alneyadi A, Alsamri H, Alrashedi A, Palakott A, El-Tarabily KA, Eid AH, Al Dhaheri Y, Iratni R. Origanum majorana Essential Oil Triggers p38 MAPK-Mediated Protective Autophagy, Apoptosis, and Caspase-Dependent Cleavage of P70S6K in Colorectal Cancer Cells. Biomolecules 2020; 10:biom10030412. [PMID: 32155920 PMCID: PMC7175132 DOI: 10.3390/biom10030412] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 02/26/2020] [Accepted: 02/26/2020] [Indexed: 12/16/2022] Open
Abstract
Colorectal cancer (CRC) is the third most common type of cancer in terms of incidence and mortality worldwide. Here we have investigated the anti-colon cancer potential of Origanum majorana essential oil (OMEO) and its underlying mechanisms of action. We showed that OMEO significantly inhibited the cellular viability and colony growth of human HT-29 colorectal cancer cells. OMEO induced protective autophagy, associated with downregulation of the mTOR/p70S6K pathway, and activated caspase-8 and caspase-9-dependent apoptosis. Blockade of autophagy with 3-methyladenine (3-MA) and chloroquine (CQ), two autophagy inhibitors, potentiated the OMEO-induced apoptotic cell death. Inversely, inhibition of apoptosis with the pan-caspase inhibitor, Z-VAD-FMK, significantly reduced cell death, suggesting that apoptosis represents the main mechanism of OMEO-induced cell death. Mechanistically, we found that OMEO induces protective autophagy and apoptotic cells death via the activation of the p38 MAPK signaling pathway. Pharmacological inhibition of p38 MAPK by the p38 inhibitors SB 202190 and SB 203580 not only significantly decreased apoptotic cell death, but also reduced the autophagy level in OMEO treated HT-29 cells. Strikingly, we found that OMEO also induces p38 MAPK-mediated caspase-dependent cleavage of p70S6K, a protein reported to be overexpressed in colon cancer and associated with drug resistance. Our findings suggest that OMEO inhibits colon cancer through p38 MAPK-mediated protective autophagy and apoptosis associated with caspase-dependent cleavage of p70S6K. To the best of our knowledge, this study is the first to report on the implications of the p38 MAPK signaling pathway in targeting p70S6K to caspase cleavage.
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Affiliation(s)
- Khawlah Athamneh
- Department of Biology, College of Science, UAE University, United Arab Emirates University, Al-Ain P.O. Box 15551, UAE; (K.A.); (A.A.); (H.A.); (A.A.); (A.P.); (K.A.E.-T.); (Y.A.D.)
| | - Aysha Alneyadi
- Department of Biology, College of Science, UAE University, United Arab Emirates University, Al-Ain P.O. Box 15551, UAE; (K.A.); (A.A.); (H.A.); (A.A.); (A.P.); (K.A.E.-T.); (Y.A.D.)
| | - Halima Alsamri
- Department of Biology, College of Science, UAE University, United Arab Emirates University, Al-Ain P.O. Box 15551, UAE; (K.A.); (A.A.); (H.A.); (A.A.); (A.P.); (K.A.E.-T.); (Y.A.D.)
| | - Asma Alrashedi
- Department of Biology, College of Science, UAE University, United Arab Emirates University, Al-Ain P.O. Box 15551, UAE; (K.A.); (A.A.); (H.A.); (A.A.); (A.P.); (K.A.E.-T.); (Y.A.D.)
| | - Abdulrasheed Palakott
- Department of Biology, College of Science, UAE University, United Arab Emirates University, Al-Ain P.O. Box 15551, UAE; (K.A.); (A.A.); (H.A.); (A.A.); (A.P.); (K.A.E.-T.); (Y.A.D.)
| | - Khaled A. El-Tarabily
- Department of Biology, College of Science, UAE University, United Arab Emirates University, Al-Ain P.O. Box 15551, UAE; (K.A.); (A.A.); (H.A.); (A.A.); (A.P.); (K.A.E.-T.); (Y.A.D.)
- Khalifa Center for Genetic Engineering and Biotechnology, United Arab Emirates University, Al-Ain P.O. Box 15551, UAE
| | - Ali H. Eid
- Department of Pharmacology and Toxicology, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon;
| | - Yusra Al Dhaheri
- Department of Biology, College of Science, UAE University, United Arab Emirates University, Al-Ain P.O. Box 15551, UAE; (K.A.); (A.A.); (H.A.); (A.A.); (A.P.); (K.A.E.-T.); (Y.A.D.)
| | - Rabah Iratni
- Department of Biology, College of Science, UAE University, United Arab Emirates University, Al-Ain P.O. Box 15551, UAE; (K.A.); (A.A.); (H.A.); (A.A.); (A.P.); (K.A.E.-T.); (Y.A.D.)
- Correspondence: ; Tel.: +971-3-713-6526; Fax: +971-3-7134927
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12
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Lapointe S, Mason W, MacNeil M, Harlos C, Tsang R, Sederias J, Luchman HA, Weiss S, Rossiter JP, Tu D, Seymour L, Smoragiewicz M. A phase I study of vistusertib (dual mTORC1/2 inhibitor) in patients with previously treated glioblastoma multiforme: a CCTG study. Invest New Drugs 2019; 38:1137-1144. [PMID: 31707687 DOI: 10.1007/s10637-019-00875-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 10/23/2019] [Indexed: 12/21/2022]
Abstract
The PI3K/AKT/mTOR pathway activation plays a central role in glioblastoma multiforme (GBM) development and progression, and in resistance to anti-cancer therapies. Inhibition of the PI3K pathway has been shown to sensitize cultured glioma cells and tumor xenografts to the effects of temozolomide (TMZ) and radiation. Vistusertib is an oral inhibitor of mTORC1/2 complexes. The primary objective of this Canadian Cancer Trials Group phase I study was to determine the recommended phase II dose (RP2D) of vistusertib in patients with GBM receiving TMZ at first progression following primary treatment. Vistusertib was administered at a starting dose of 100 mg bid 2 days on/5 days off weekly with TMZ 150 mg/m2 daily for 5 days/28-days cycle. Dose escalation was according to a 3 + 3 design. Secondary objectives included assessment of vistusertib safety and toxicity profile, and preliminary efficacy. 15 patients were enrolled in the study (median age 66 (range 51-77), females 8). Vistusertib 125 mg BID in combination with TMZ 150 mg/m2 daily for 5 days was well tolerated. Vistusertib treatment-related adverse events were generally grade 1-2, with the most frequently reported being fatigue, gastrointestinal symptoms, and rash. Of 13 response evaluable patients, 1 patient (8%) had a partial response ongoing at 7.6 months of follow-up, and 5 patients had stable disease (38%) as best response (median duration 9.6 months, range 3.7-not yet reached). Six-month progression-free survival (PFS) rate was 26.6%. Combination of vistusertib with TMZ in GBM patients at first recurrence demonstrated a favorable safety profile at the tested dose levels.
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Affiliation(s)
- Sarah Lapointe
- Division of Neurology, Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada
- Division of Neuro-Oncology, Pencer Brain Tumor Center, University Health Network-Princess Margaret Hospital, Toronto, ON, Canada
| | - Warren Mason
- Division of Neuro-Oncology, Pencer Brain Tumor Center, University Health Network-Princess Margaret Hospital, Toronto, ON, Canada
| | - Mary MacNeil
- QEII Health Sciences Centre, Halifax, NS, Canada
| | | | - Roger Tsang
- Tom Baker Cancer Center, Calgary, AB, Canada
| | - Joana Sederias
- Canadian Cancer Trials Group, Queen's University, Kingston, ON, K7L3N6, Canada
| | - H Artee Luchman
- Arnie Charbonneau Cancer Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Samuel Weiss
- Arnie Charbonneau Cancer Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - John P Rossiter
- Department of Pathology and Molecular Medicine, Queen's University, Kingston, ON, Canada
| | - Dongsheng Tu
- Canadian Cancer Trials Group, Queen's University, Kingston, ON, K7L3N6, Canada
| | - Lesley Seymour
- Canadian Cancer Trials Group, Queen's University, Kingston, ON, K7L3N6, Canada
| | - Martin Smoragiewicz
- Canadian Cancer Trials Group, Queen's University, Kingston, ON, K7L3N6, Canada.
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Murugan AK. mTOR: Role in cancer, metastasis and drug resistance. Semin Cancer Biol 2019; 59:92-111. [PMID: 31408724 DOI: 10.1016/j.semcancer.2019.07.003] [Citation(s) in RCA: 259] [Impact Index Per Article: 51.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 06/14/2019] [Accepted: 07/03/2019] [Indexed: 02/09/2023]
Abstract
Mammalian target of rapamycin (mTOR) is a serine/threonine kinase that gets inputs from the amino acids, nutrients, growth factor, and environmental cues to regulate varieties of fundamental cellular processes which include protein synthesis, growth, metabolism, aging, regeneration, autophagy, etc. The mTOR is frequently deregulated in human cancer and activating somatic mutations of mTOR were recently identified in several types of human cancer and hence mTOR is therapeutically targeted. mTOR inhibitors were commonly used as immunosuppressors and currently, it is approved for the treatment of human malignancies. This review briefly focuses on the structure and biological functions of mTOR. It extensively discusses the genetic deregulation of mTOR including amplifications and somatic mutations, mTOR-mediated cell growth promoting signaling, therapeutic targeting of mTOR and the mechanisms of resistance, the role of mTOR in precision medicine and other recent advances in further understanding the role of mTOR in cancer.
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Affiliation(s)
- Avaniyapuram Kannan Murugan
- Department of Molecular Oncology, King Faisal Specialist Hospital & Research Centre, PO Box 3354, Research Center (MBC 03), Riyadh, 11211, Saudi Arabia.
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14
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Extracellular Vesicles Released by Glioblastoma Cells Stimulate Normal Astrocytes to Acquire a Tumor-Supportive Phenotype Via p53 and MYC Signaling Pathways. Mol Neurobiol 2018; 56:4566-4581. [PMID: 30353492 PMCID: PMC6505517 DOI: 10.1007/s12035-018-1385-1] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 10/09/2018] [Indexed: 12/18/2022]
Abstract
The role of astrocytes is becoming increasingly important to understanding how glioblastoma (GBM) tumor cells diffusely invade the brain. Yet, little is known of the contribution of extracellular vesicle (EV) signaling in GBM/astrocyte interactions. We modeled GBM-EV signaling to normal astrocytes in vitro to assess whether this mode of intercellular communication could support GBM progression. EVs were isolated and characterized from three patient-derived GBM stem cells (NES+/CD133+) and their differentiated (diff) progeny cells (NES−/CD133−). Uptake of GBM-EVs by normal primary astrocytes was confirmed by fluorescence microscopy, and changes in astrocyte podosome formation and gelatin degradation were measured. Quantitative mass spectrometry-based proteomics was performed on GBM-EV stimulated astrocytes. Interaction networks were generated from common, differentially abundant proteins using Ingenuity® (Qiagen Bioinformatics) and predicted upstream regulators were tested by qPCR assays. Podosome formation and Cy3-gelatin degradation were induced in astrocytes following 24-h exposure to GBM-stem and -diff EVs, with EVs released by GBM-stem cells eliciting a greater effect. More than 1700 proteins were quantified, and bioinformatics predicted activations of MYC, NFE2L2, FN1, and TGFβ1 and inhibition of TP53 in GBM-EV stimulated astrocytes that were then confirmed by qPCR. Further qPCR studies identified significantly decreased Δ133p53 and increased p53β in astrocytes exposed to GBM-EVs that might indicate the acquisition of a pro-inflammatory, tumor-promoting senescence-associated secretory phenotype (SASP). Inhibition of TP53 and activation of MYC signaling pathways in normal astrocytes exposed to GBM-EVs may be a mechanism by which GBM manipulates astrocytes to acquire a phenotype that promotes tumor progression.
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15
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Huang Y, Hu K, Zhang S, Dong X, Yin Z, Meng R, Zhao Y, Dai X, Zhang T, Yang K, Liu L, Huang K, Shi S, Zhang Y, Chen J, Wu G, Xu S. S6K1 phosphorylation-dependent degradation of Mxi1 by β-Trcp ubiquitin ligase promotes Myc activation and radioresistance in lung cancer. Theranostics 2018; 8:1286-1300. [PMID: 29507620 PMCID: PMC5835936 DOI: 10.7150/thno.22552] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Accepted: 11/20/2017] [Indexed: 12/26/2022] Open
Abstract
Rationale: Mxi1 is regarded as a potential tumor suppressor protein that antagonizes the transcriptional activity of proto-oncogene Myc. However, the clinical significances and underlying mechanisms by which Mxi1 is regulated in lung cancer remain poorly understood. Methods: Mass spectrometry analysis and immunoprecipitation assay were utilized to detect the protein-protein interaction. The phosphorylation of Mxi1 was evaluated by in vitro kinase assays. Poly-ubiquitination of Mxi1 was examined by in vivo ubiquitination assay. Lung cancer cells stably expressing wild-type Mxi1 or Mxi1-S160A were used for functional analyses. The expression levels of Mxi1 and S6K1 were determined by immunohistochemistry in lung cancer tissues and adjacent normal lung tissues. Results: We found that Mxi1 is downregulated and correlated with poor prognosis in lung cancer. Using tandem affinity purification technology, we provided evidence that β-Trcp E3 ubiquitin ligase interacts with and promotes the ubiquitination and degradation of Mxi1. Furthermore, we demonstrated that Mxi1 is phosphorylated at S160 site by the protein kinase S6K1 and subsequently degraded via the ubiquitin ligase β-Trcp. Moreover, a phosphorylation mutant form of Mxi1 (Mxi1-S160A), which cannot be degraded by S6K1 and β-Trcp, is much more stable and efficient in suppressing the transcriptional activity of Myc and radioresistance in lung cancer cells. More importantly, a strong inverse correlation between S6K1 and Mxi1 expression was observed in human lung cancer tissues. Conclusion: Our findings not only establish a crosstalk between the mTOR/S6K1 signaling pathway and Myc activation, but also suggest that targeting S6K1/Mxi1 pathway is a promising therapeutic strategy for the treatment of lung cancer.
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16
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Yamada D, Takahashi K, Kawahara K, Maeda T. Autocrine Semaphorin3A signaling is essential for the maintenance of stem-like cells in lung cancer. Biochem Biophys Res Commun 2016; 480:375-379. [DOI: 10.1016/j.bbrc.2016.10.057] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Accepted: 10/18/2016] [Indexed: 01/24/2023]
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Qiu ZX, Sun RF, Mo XM, Li WM. The p70S6K Specific Inhibitor PF-4708671 Impedes Non-Small Cell Lung Cancer Growth. PLoS One 2016; 11:e0147185. [PMID: 26771549 PMCID: PMC4714881 DOI: 10.1371/journal.pone.0147185] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 12/30/2015] [Indexed: 02/05/2023] Open
Abstract
Background As a serine/threonine protein kinase, p70S6K plays an important role in tumor cells. Evidence has revealed overexpression of p70S6K and phosphorylated p70S6K (p-p70S6K) in various tumor tissues, with these proteins identified as independent prognostic markers in non-small cell lung cancer (NSCLC). In this study, we explored the role of the p70S6K specific inhibitor PF-4708671 in NSCLC. Methods Three NSCLC cell lines (A549, SK-MES-1, and NCI-H460) were treated with PF-4708671 at five different concentrations, including 0.1μM, 0.3μM, 1μM, 3μM and 10μM, and protein levels were determined by Western-blot. Then, PF-4708671’s effects were assessed both in vitro (cell proliferation, apoptosis, cell cycle distribution, and invasion) and in vivo. Results The expression levels of p-p70S6K and the downstream effector S6 were significantly reduced by PF-4708671. Diametrically opposite, the downstream protein levels of BAD, Caspase3 and ERK had increased after treatment with PF-4708671. In addition, PF-4708671 drastically inhibited cell proliferation and invasion ability in A549, SK-MES-1 and NCI-H460 cells in vitro, causing cell cycle arrest in G0-G1 phase. Limited effects of PF-4708671 were observed on apoptosis in the three NSCLC cell lines assessed. Importantly, PF-4708671 could inhibit tumorigenesis in nude mice in vivo. Conclusion These findings demonstrated that the p70S6K specific inhibitor PF-4708671 has inhibitory effects on NSCLC tumorigenesis in vitro and in vivo. Therefore, P70S6K should be considered a new potential therapeutic target, and PF-470867 may be used as targeted drug for cancer treatment.
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Affiliation(s)
- Zhi-Xin Qiu
- Department of Respiratory Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Rong-Fei Sun
- Department of Respiratory Medicine, Tianjin First Central Hospital, Tianjin, 300192, China
| | - Xian-Ming Mo
- Laboratory of Stem Cell Biology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Wei-Min Li
- Department of Respiratory Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China
- * E-mail:
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18
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Redelsperger IM, Taldone T, Riedel ER, Lepherd ML, Lipman NS, Wolf FR. Stability of Doxycycline in Feed and Water and Minimal Effective Doses in Tetracycline-Inducible Systems. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE : JAALAS 2016; 55:467-474. [PMID: 27423155 PMCID: PMC4943619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 07/07/2015] [Accepted: 11/09/2015] [Indexed: 06/06/2023]
Abstract
Despite the extensive use of doxycycline in tetracycline-inducible rodent models, little is known regarding its stability in feed or water or the most effective route or dose. We assessed the concentrations of doxycycline in reverse-osmosis-purified (RO; pH 6.0) and acidified RO (pH 2.6) water in untinted or green-tinted bottles. Doxycycline remained stable in all groups for 7 d and in acidified water in untinted bottles for 14 d. Fungal growth occurred in nonacidified water in tinted and untinted bottles by 12 and 14 d, respectively, and in tinted bottles containing acidified water on day 14, but not in untinted bottles with acidified water. Doxycycline concentrations were also assessed before and at various points after the pelleting of feed from 2 vendors. Each batch was divided for storage at 4 °C, at room temperature, or within ventilated mouse isolator cages and then sampled monthly for 6 mo. Drying caused the greatest decline in doxycycline concentration, whereas γ-irradiation plus shipping and storage condition had minimal effect. Two mouse lines with tetracycline-inducible promoters received 25, 150, or 467 μg/mL or 2 mg/mL doxycycline in water and 200 or 625 ppm in feed before analysis of GFP expression. GFP was expressed in Rosa-rtTA2 mice at 150 μg/mL, whereas Cags-rtTA3 mice required 25 μg/mL. These studies indicate that 1) doxycycline-compounded feed can be handled in the same manner as standard rodent feed, 2) tinted water bottles are not necessary for maintaining drug concentrations, and 3) concentrations lower than those used typically may be effective in lines with tetracycline-inducible promoters.
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Affiliation(s)
- Irka M Redelsperger
- Tri-Institutional Training Program in Laboratory Animal Medicine and Science, Memorial Sloan Kettering Cancer Center, Weill Cornell Medical College, and The Rockefeller University, New York, USA; Taconic Biosciences, Rensselaer, New York, USA.
| | - Tony Taldone
- Memorial Sloan Kettering Cancer Center, New York, USA
| | - Elyn R Riedel
- Memorial Sloan Kettering Cancer Center, New York, USA
| | - Michelle L Lepherd
- Tri-Institutional Training Program in Laboratory Animal Medicine and Science, Memorial Sloan Kettering Cancer Center, Weill Cornell Medical College, and The Rockefeller University, Memorial Sloan Kettering Cancer Center, New York, USA; The Rockefeller University, Weill Cornell Medical College, New York, USA
| | - Neil S Lipman
- Tri-Institutional Training Program in Laboratory Animal Medicine and Science, Memorial Sloan Kettering Cancer Center, Weill Cornell Medical College, and The Rockefeller University, Memorial Sloan Kettering Cancer Center, Weill Cornell Medical College, New York, USA
| | - Felix R Wolf
- Tri-Institutional Training Program in Laboratory Animal Medicine and Science, Memorial Sloan Kettering Cancer Center, Weill Cornell Medical College, and The Rockefeller University, Memorial Sloan Kettering Cancer Center, Weill Cornell Medical College, New York, USA.
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19
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Huang L, Xu W, Yan D, Dai L, Shi X. Identification of expression quantitative trait loci of RPTOR for susceptibility to glioma. Tumour Biol 2015; 37:2305-11. [PMID: 26361958 DOI: 10.1007/s13277-015-3956-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 08/19/2015] [Indexed: 11/30/2022] Open
Abstract
Expression quantitative trait loci (eQTLs) have been recognized to be more likely to associate with complex diseases including cancer. As an essential scaffold for MTOR complex 1, RPTOR is necessary for the MTOR-catalyzed phosphorylation. This study examined the associations between the eQTLs of RPTOR and glioma susceptibility. The eQTLs of RPTOR were obtained from GTEx eQTL Browser. Associations were estimated by logistic regression models. On the basis of analysis of 138 cases with glioma and 327 cancer-free population controls, we demonstrated that the eQTL of RPTOR, rs7502563, was significantly associated with a decreased glioma risk [odds ratio (OR) = 0.59, 95 % confidence interval (CI) = 0.38-0.89, P = 0.0123] in a dominant manner. Stratified analyses indicated that the association between rs7502563 and glioma was more pronounced in females (OR = 0.40, 95 % CI = 0.20-0.80, P = 0.0091), older subjects (OR = 0.47, 95 % CI = 0.26-0.86, P = 0.0135), and subjects with high-grade glioma (OR = 0.45, 95 % CI = 0.27-0.77, P = 0.0031). Moreover, an interest gradual decrease in OR with higher grade glioma was observed. Further analysis of the extracted data from GTEx eQTL Browser found that rs7502563 G allele was associated with significantly higher expression of RPTOR in all HapMap populations. Our results demonstrate for the first time that the eQTL of RPTOR, rs7502563, is susceptible to glioma.
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Affiliation(s)
- Liming Huang
- The First Department of Chemotherapy, The First Affiliated Hospital, Fujian Medical University, Fuzhou, 350005, China
| | - Wenshen Xu
- Department of Laboratory Medicine, The First Affiliated Hospital, Fujian Medical University, Fuzhou, 350005, China
| | - Danfang Yan
- Department of Radiation Oncology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, China
| | - Lian Dai
- Department of Medicine, The Third Affiliated People's Hospital, Fujian University of Traditional Chinese Medicine, Fuzhou, 350108, China.
| | - Xi Shi
- The First Department of Chemotherapy, The First Affiliated Hospital, Fujian Medical University, Fuzhou, 350005, China.
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Byun S, Lim S, Mun JY, Kim KH, Ramadhar TR, Farrand L, Shin SH, Thimmegowda NR, Lee HJ, Frank DA, Clardy J, Lee SW, Lee KW. Identification of a Dual Inhibitor of Janus Kinase 2 (JAK2) and p70 Ribosomal S6 Kinase1 (S6K1) Pathways. J Biol Chem 2015; 290:23553-62. [PMID: 26242912 DOI: 10.1074/jbc.m115.662445] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Indexed: 01/06/2023] Open
Abstract
Bioactive phytochemicals can suppress the growth of malignant cells, and investigation of the mechanisms responsible can assist in the identification of novel therapeutic strategies for cancer therapy. Ginger has been reported to exhibit potent anti-cancer effects, although previous reports have often focused on a narrow range of specific compounds. Through a direct comparison of various ginger compounds, we determined that gingerenone A selectively kills cancer cells while exhibiting minimal toxicity toward normal cells. Kinase array screening revealed JAK2 and S6K1 as the molecular targets primarily responsible for gingerenone A-induced cancer cell death. The effect of gingerenone A was strongly associated with relative phosphorylation levels of JAK2 and S6K1, and administration of gingerenone A significantly suppressed tumor growth in vivo. More importantly, the combined inhibition of JAK2 and S6K1 by commercial inhibitors selectively induced apoptosis in cancer cells, whereas treatment with either agent alone did not. These findings provide rationale for dual targeting of JAK2 and S6K1 in cancer for a combinatorial therapeutic approach.
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Affiliation(s)
- Sanguine Byun
- From the Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270, Republic of Korea
| | - Semi Lim
- WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Seoul 151-742, Republic of Korea
| | - Ji Young Mun
- Department of Biomedical Laboratory Science, College of Health Sciences, Eulji University, Seongnam 461-463, Republic of Korea
| | - Ki Hyun Kim
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, School of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea
| | - Timothy R Ramadhar
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115
| | - Lee Farrand
- Yuhan Research Institute, Yuhan Corp., Yongin 446-902, Republic of Korea
| | - Seung Ho Shin
- Program in Biomedical Informatics and Computational Biology, University of Minnesota, Minneapolis, Minnesota 55455
| | - N R Thimmegowda
- Department of Chemistry, Government Sri Krishnarajendra Silver Jubilee Technological Institute, Bangalore 560001, India, World Class Institute, Korea Research Institute of Bioscience and Biotechnology, Ochang 363-883, Korea
| | - Hyong Joo Lee
- WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Seoul 151-742, Republic of Korea
| | - David A Frank
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, and
| | - Jon Clardy
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115,
| | - Sam W Lee
- From the Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129,
| | - Ki Won Lee
- Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270, Republic of Korea, WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Seoul 151-742, Republic of Korea,
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Mroue R, Huang B, Braunstein S, Firestone AJ, Nakamura JL. Monoallelic loss of the imprinted gene Grb10 promotes tumor formation in irradiated Nf1+/- mice. PLoS Genet 2015; 11:e1005235. [PMID: 26000738 PMCID: PMC4441450 DOI: 10.1371/journal.pgen.1005235] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 04/22/2015] [Indexed: 12/26/2022] Open
Abstract
Imprinted genes are expressed from only one parental allele and heterozygous loss involving the expressed allele is sufficient to produce complete loss of protein expression. Genetic alterations are common in tumorigenesis but the role of imprinted genes in this process is not well understood. In earlier work we mutagenized mice heterozygous for the Neurofibromatosis I tumor suppressor gene (NF1) to model radiotherapy-associated second malignant neoplasms that arise in irradiated NF1 patients. Expression analysis of tumor cell lines established from our mouse models identified Grb10 expression as widely absent. Grb10 is an imprinted gene and polymorphism analysis of cell lines and primary tumors demonstrates that the expressed allele is commonly lost in diverse Nf1 mutant tumors arising in our mouse models. We performed functional studies to test whether Grb10 restoration or loss alter fundamental features of the tumor growth. Restoring Grb10 in Nf1 mutant tumors decreases proliferation, decreases soft agar colony formation and downregulates Ras signaling. Conversely, Grb10 silencing in untransformed mouse embryo fibroblasts significantly increased cell proliferation and increased Ras-GTP levels. Expression of a constitutively activated MEK rescued tumor cells from Grb10-mediated reduction in colony formation. These studies reveal that Grb10 loss can occur during in vivo tumorigenesis, with a functional consequence in untransformed primary cells. In tumors, Grb10 loss independently promotes Ras pathway hyperactivation, which promotes hyperproliferation, an early feature of tumor development. In the context of a robust Nf1 mutant mouse model of cancer this work identifies a novel role for an imprinted gene in tumorigenesis. Cancer-causing mutations typically involve either allele inherited from parents, and the parental source of a mutant allele is not known to influence the cancer phenotype. Imprinted genes are a class of genes whose expression is determined by a specific parental allele, either maternally or paternally derived. Thus, in contrast to most genes, the pattern of inheritance (maternal or paternal-derived) strongly influences the expression of an imprinted gene. Furthermore, imprinted genes can be differentially expressed in different tissue types. This work identifies a novel link between cancer and Grb10, an imprinted gene involved in organismal metabolism and growth. In our mouse model of radiation-induced tumors, we found monoallelic Grb10 gene loss involving the parental allele responsible for protein expression. Tumors harboring genetic loss of the expressed Grb10 allele showed absent transcript and total protein levels, despite an intact remaining wildtype Grb10 allele identified by sequencing. When restored, Grb10 suppressed tumor growth by down-regulating Ras signaling. This work demonstrates a new role for an imprinted gene in tumor formation, and shows that Grb10 functions to negatively regulate Ras signaling and suppress hyperproliferation.
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Affiliation(s)
- Rana Mroue
- Department of Radiation Oncology, University of California, San Francisco, San Francisco, California, United States of America
| | - Brian Huang
- Department of Radiation Oncology, University of California, San Francisco, San Francisco, California, United States of America
| | - Steve Braunstein
- Department of Radiation Oncology, University of California, San Francisco, San Francisco, California, United States of America
| | - Ari J Firestone
- Department of Pediatrics, University of California, San Francisco, San Francisco, California, United States of America
| | - Jean L Nakamura
- Department of Radiation Oncology, University of California, San Francisco, San Francisco, California, United States of America
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Lamour V, Henry A, Kroonen J, Nokin MJ, von Marschall Z, Fisher LW, Chau TL, Chariot A, Sanson M, Delattre JY, Turtoi A, Peulen O, Rogister B, Castronovo V, Bellahcène A. Targeting osteopontin suppresses glioblastoma stem-like cell character and tumorigenicityin vivo. Int J Cancer 2015; 137:1047-57. [DOI: 10.1002/ijc.29454] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 11/24/2014] [Accepted: 12/10/2014] [Indexed: 01/08/2023]
Affiliation(s)
- Virginie Lamour
- Metastasis Research Laboratory, GIGA-Cancer, University of Liège; Belgium
| | - Aurélie Henry
- Metastasis Research Laboratory, GIGA-Cancer, University of Liège; Belgium
| | - Jérôme Kroonen
- Laboratory of Developmental Neurobiology, GIGA-Neurosciences, University of Liège; Belgium
| | - Marie-Julie Nokin
- Metastasis Research Laboratory, GIGA-Cancer, University of Liège; Belgium
| | | | - Larry W. Fisher
- Craniofacial and Skeletal Diseases Branch, NIDCR, NIH, DHHS; Bethesda MD
| | - Tieu-Lan Chau
- Laboratory of Medical Chemistry, GIGA-Signal Transduction, University of Liège; Belgium
| | - Alain Chariot
- Laboratory of Medical Chemistry, GIGA-Signal Transduction, University of Liège; Belgium
| | - Marc Sanson
- UMR 975, INSERM-UPMC, GH Pitié-Salpêtrière; Paris
| | | | - Andrei Turtoi
- Metastasis Research Laboratory, GIGA-Cancer, University of Liège; Belgium
| | - Olivier Peulen
- Metastasis Research Laboratory, GIGA-Cancer, University of Liège; Belgium
| | - Bernard Rogister
- Laboratory of Developmental Neurobiology, GIGA-Neurosciences, University of Liège; Belgium
- Stem Cells and Regenerative Medicine, GIGA-Development, University of Liège; Belgium
| | - Vincent Castronovo
- Metastasis Research Laboratory, GIGA-Cancer, University of Liège; Belgium
| | - Akeila Bellahcène
- Metastasis Research Laboratory, GIGA-Cancer, University of Liège; Belgium
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Rana S, Blowers EC, Natarajan A. Small molecule adenosine 5'-monophosphate activated protein kinase (AMPK) modulators and human diseases. J Med Chem 2014; 58:2-29. [PMID: 25122135 DOI: 10.1021/jm401994c] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Adenosine 5'-monophosphate activated protein kinase (AMPK) is a master sensor of cellular energy status that plays a key role in the regulation of whole-body energy homeostasis. AMPK is a serine/threonine kinase that is activated by upstream kinases LKB1, CaMKKβ, and Tak1, among others. AMPK exists as αβγ trimeric complexes that are allosterically regulated by AMP, ADP, and ATP. Dysregulation of AMPK has been implicated in a number of metabolic diseases including type 2 diabetes mellitus and obesity. Recent studies have associated roles of AMPK with the development of cancer and neurological disorders, making it a potential therapeutic target to treat human diseases. This review focuses on the structure and function of AMPK, its role in human diseases, and its direct substrates and provides a brief synopsis of key AMPK modulators and their relevance in human diseases.
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Affiliation(s)
- Sandeep Rana
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center , Omaha, Nebraska 68198-6805, United States
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Ohba S, Mukherjee J, See WL, Pieper RO. Mutant IDH1-driven cellular transformation increases RAD51-mediated homologous recombination and temozolomide resistance. Cancer Res 2014; 74:4836-44. [PMID: 25035396 DOI: 10.1158/0008-5472.can-14-0924] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Isocitrate dehydrogenase 1 (IDH1) mutations occur in most lower grade glioma and not only drive gliomagenesis but are also associated with longer patient survival and improved response to temozolomide. To investigate the possible causative relationship between these events, we introduced wild-type (WT) or mutant IDH1 into immortalized, untransformed human astrocytes, then monitored transformation status and temozolomide response. Temozolomide-sensitive parental cells exhibited DNA damage (γ-H2AX foci) and a prolonged G2 cell-cycle arrest beginning three days after temozolomide (100 μmol/L, 3 hours) exposure and persisting for more than four days. The same cells transformed by expression of mutant IDH1 exhibited a comparable degree of DNA damage and cell-cycle arrest, but both events resolved significantly faster in association with increased, rather than decreased, clonogenic survival. The increases in DNA damage processing, cell-cycle progression, and clonogenicity were unique to cells transformed by mutant IDH1, and were not noted in cells transformed by WT IDH1 or an oncogenic form (V12H) of Ras. Similarly, these effects were not noted following introduction of mutant IDH1 into Ras-transformed cells or established glioma cells. They were, however, associated with increased homologous recombination (HR) and could be reversed by the genetic or pharmacologic suppression of the HR DNA repair protein RAD51. These results show that mutant IDH1 drives a unique set of transformative events that indirectly enhance HR and facilitate repair of temozolomide-induced DNA damage and temozolomide resistance. The results also suggest that inhibitors of HR may be a viable means to enhance temozolomide response in IDH1-mutant glioma.
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Affiliation(s)
- Shigeo Ohba
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, California
| | - Joydeep Mukherjee
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, California
| | - Wendy L See
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, California
| | - Russell O Pieper
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, California
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Krawczyk J, Keane N, Swords R, O'Dwyer M, Freeman CL, Giles FJ. Perifosine--a new option in treatment of acute myeloid leukemia? Expert Opin Investig Drugs 2013; 22:1315-27. [PMID: 23931614 DOI: 10.1517/13543784.2013.826648] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
INTRODUCTION Perifosine is a novel targeted oral Akt inhibitor. In preclinical leukemia models, perifosine has an independent cytotoxic potential but also synergizes well with other rationally selected targeted agents. The evidence from clinical trials supporting the use of perifosine in the therapy of leukemias is limited. The optimal dose and schedule have yet to be defined. However, given its favorable toxicity profile and mechanism of action, the therapeutic potential of perifosine should be evaluated in well-designed clinical trials. AREAS COVERED The role of the phosphatidylinositol-3 kinase (PI3K)/Akt zpathway in normal cells, cancer and leukemias is discussed. The mechanism of action of perifosine and the basic information on the development and chemical properties are summarized. The evidence from in vivo and in vitro studies is presented. The efficacy and side effect profile are summarized. EXPERT OPINION The safety and tolerability profile of perifosine are satisfactory. The evidence from clinical trials in patients with leukemias is very limited. The preclinical data are encouraging. Perifosine has the potential to play a role in the treatment of leukemias in the future. Its role needs to be confirmed in clinical trials.
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Crystal structures of S6K1 provide insights into the regulation mechanism of S6K1 by the hydrophobic motif. Biochem J 2013; 454:39-47. [DOI: 10.1042/bj20121863] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The activity of S6K1 (p70 ribosomal protein subunit 6 kinase 1) is stimulated by phosphorylation of Thr389 in the hydrophobic motif by mTORC1 (mammalian target of rapamycin complex 1) and phosphorylation of Thr229 in the activation loop by PDK1 (phosphoinositide-dependent kinase 1); however, the order of the two events is still ambiguous. In the present paper we report six crystal structures of the S6K1 kinase domain alone or plus the hydrophobic motif in various forms, in complexes with a highly specific inhibitor. The structural data, together with the biochemical data, reveal in vivo phosphorylation of Thr389 in the absence of Thr229 phosphorylation and demonstrate the importance of two conserved residues, Gln140 and Arg121, in the establishment of a hydrogen-bonding network between the N-lobe (N-terminal lobe) and the hydrophobic motif. Phosphorylation of Thr389 or introduction of a corresponding negatively charged group leads to reinforcement of the network and stabilization of helix αC. Furthermore, comparisons of S6K1 with other AGC (protein kinase A/protein kinase G/protein kinase C) family kinases suggest that the structural and sequence differences in the hydrophobic motif and helix αC account for their divergence in PDK1 dependency. Taken together, the results of the present study indicate that phosphorylation of the hydrophobic motif in S6K1 is independent of, and probably precedes and promotes, phosphorylation of the activation loop.
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Mukherjee J, Phillips JJ, Zheng S, Wiencke J, Ronen SM, Pieper RO. Pyruvate kinase M2 expression, but not pyruvate kinase activity, is up-regulated in a grade-specific manner in human glioma. PLoS One 2013; 8:e57610. [PMID: 23451252 PMCID: PMC3581484 DOI: 10.1371/journal.pone.0057610] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Accepted: 01/24/2013] [Indexed: 02/04/2023] Open
Abstract
Normal tissues express the M1 isoform of pyruvate kinase (PK) that helps generate and funnel pyruvate into the mitochondria for ATP production. Tumors, in contrast, express the less active PKM2 isoform, which limits pyruvate production and spares glycolytic intermediates for the generation of macromolecules needed for proliferation. Although high PKM2 expression and low PK activity are considered defining features of tumors, very little is known about how PKM expression and PK activity change along the continuum from low grade to high grade tumors, and how these changes relate to tumor growth. To address this issue, we measured PKM isoform expression and PK activity in normal brain, neural progenitor cells, and in a series of over 100 astrocytomas ranging from benign grade I pilocytic astrocytomas to highly aggressive grade IV glioblastoma multiforme (GBM). All glioma exhibited comparably reduced levels of PKM1 expression and PK activity relative to normal brain. In contrast, while grade I-III gliomas all had modestly increased levels of PKM2 RNA and protein expression relative to normal brain, GBM, regardless of whether they arose de novo or progressed from lower grade tumors, showed a 3-5 fold further increase in PKM2 RNA and protein expression. Low levels of PKM1 expression and PK activity were important for cell growth as PKM1 over-expression and the accompanying increases in PK activity slowed the growth of GBM cells. The increased expression of PKM2, however, was also important, because shRNA-mediated PKM2 knockdown decreased total PKM2 and the already low levels of PK activity, but paradoxically also limited cell growth in vitro and in vivo. These results show that pyruvate kinase M expression, but not pyruvate kinase activity, is regulated in a grade-specific manner in glioma, but that changes in both PK activity and PKM2 expression contribute to growth of GBM.
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Affiliation(s)
- Joydeep Mukherjee
- Department of Neurological Surgery, University of California San Francisco, San Francisco, California, United States of America
- The Brain Tumor Research Center, University of California San Francisco, San Francisco, California, United States of America
| | - Joanna J. Phillips
- Department of Neurological Surgery, University of California San Francisco, San Francisco, California, United States of America
- Department of Pathology, University of California San Francisco, San Francisco, California, United States of America
- The Brain Tumor Research Center, University of California San Francisco, San Francisco, California, United States of America
| | - Shichun Zheng
- Department of Neurological Surgery, University of California San Francisco, San Francisco, California, United States of America
- The Brain Tumor Research Center, University of California San Francisco, San Francisco, California, United States of America
| | - John Wiencke
- Department of Neurological Surgery, University of California San Francisco, San Francisco, California, United States of America
- The Brain Tumor Research Center, University of California San Francisco, San Francisco, California, United States of America
| | - Sabrina M. Ronen
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, United States of America
- The Brain Tumor Research Center, University of California San Francisco, San Francisco, California, United States of America
| | - Russell O. Pieper
- Department of Neurological Surgery, University of California San Francisco, San Francisco, California, United States of America
- The Brain Tumor Research Center, University of California San Francisco, San Francisco, California, United States of America
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Grzmil M, Hemmings BA. Overcoming resistance to rapalogs in gliomas by combinatory therapies. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:1371-80. [PMID: 23395884 DOI: 10.1016/j.bbapap.2013.01.041] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 01/30/2013] [Indexed: 12/31/2022]
Abstract
Glioblastoma is the most common and aggressive brain tumor type, with a mean patient survival of approximately 1year. Many previous analyses of the glioma kinome have identified key deregulated pathways that converge and activate mammalian target of rapamycin (mTOR). Following the identification and characterization of mTOR-promoting activity in gliomagenesis, data from preclinical studies suggested the targeting of mTOR by rapamycin or its analogs (rapalogs) as a promising therapeutic approach. However, clinical trials with rapalogs have shown very limited efficacy on glioma due to the development of resistance mechanisms. Analysis of rapalog-insensitive glioma cells has revealed increased activity of growth and survival pathways compensating for mTOR inhibition by rapalogs that are suitable for therapeutic intervention. In addition, recently developed mTOR inhibitors show high anti-glioma activity. In this review, we recapitulate the regulation of mTOR signaling and its involvement in gliomagenesis, discuss mechanisms resulting in resistance to rapalogs, and speculate on strategies to overcome resistance. This article is part of a Special Issue entitled: Inhibitors of Protein Kinases (2012).
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Affiliation(s)
- Michal Grzmil
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
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Netrin-4 promotes glioblastoma cell proliferation through integrin β4 signaling. Neoplasia 2012; 14:219-27. [PMID: 22496621 DOI: 10.1593/neo.111396] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 02/16/2012] [Accepted: 02/20/2012] [Indexed: 12/12/2022] Open
Abstract
Netrin-4 is a laminin-related secreted molecule originally found to have roles in neuronal axon migration. Recent studies have indicated that netrin-4 also participates in the development of nonneural tissues and modulates tumor cell proliferation and tumor metastasis. Here we have explored the functions and molecular mechanisms of netrin-4 in glioblastoma multiforme. The suppression of netrin-4 expression in glioblastoma cell lines significantly reduced cell proliferation and motility and increased serum deprivation-induced apoptosis. Using tandem affinity purification combined with protein identification by mass spectrometry, we found that integrin β(4) interacts with netrin-4 and that it mediates mitogenic effects as well as AKT and mammalian target of rapamycin phosphorylation induced by netrin-4. Interestingly, netrin-4 acted as an inhibitor of cell proliferation in integrin β(4)-silenced glioblastoma cells, and high concentrations of netrin-4 reduced cell proliferation. The negative effects of netrin-4 on proliferation were mediated by UNC5B. Analysis of more than 400 primary tumors from The Cancer Genome Atlas repository revealed that the expression of netrin-4 is significantly downregulated in glioblastoma and that the reduced expression is linked to poor patient survival time. The expression of integrin β(4) is increased in glioblastoma, and it predicts poor patient survival time. Current results illustrate a novel mechanism for glioma progression, where glioma cells reduce netrin-4 expression to decrease its inhibitory effects. In parallel, the expression of integrin β(4) is upregulated to sensitize the cells to low concentrations of netrin-4 for maintaining cell proliferation.
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Masui K, Cloughesy TF, Mischel PS. Review: molecular pathology in adult high-grade gliomas: from molecular diagnostics to target therapies. Neuropathol Appl Neurobiol 2012; 38:271-91. [PMID: 22098029 PMCID: PMC4104813 DOI: 10.1111/j.1365-2990.2011.01238.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The classification of malignant gliomas is moving from a morphology-based guide to a system built on molecular criteria. The development of a genomic landscape for gliomas and a better understanding of its functional consequences have led to the development of internally consistent molecular classifiers. However, development of a biologically insightful classification to guide therapy is still a work in progress. Response to targeted treatments is based not only on the presence of drugable targets, but rather on the molecular circuitry of the cells. Further, tumours are heterogeneous and change and adapt in response to drugs. Therefore, the challenge of developing molecular classifiers that provide meaningful ways to stratify patients for therapy remains a major challenge for the field. In this review, we examine the potential role of MGMT methylation, IDH1/2 mutations, 1p/19q deletions, aberrant epidermal growth factor receptor and PI3K pathways, abnormal p53/Rb pathways, cancer stem-cell markers and microRNAs as prognostic and predictive molecular markers in the setting of adult high-grade gliomas and we outline the clinically relevant subtypes of glioblastoma with genomic, transcriptomic and proteomic integrated analyses. Furthermore, we describe how these advances, especially in epidermal growth factor receptor/PI3K/mTOR signalling pathway, affect our approaches towards targeted therapy, raising new challenges and identifying new leads.
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Affiliation(s)
- K Masui
- Department of Pathology and Laboratory Medicine, David Geffen University of California at Los Angeles School of Medicine, Los Angeles, California, USA.
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Overexpression of s6 kinase 1 in brain tumours is associated with induction of hypoxia-responsive genes and predicts patients' survival. JOURNAL OF ONCOLOGY 2012; 2012:416927. [PMID: 22570651 PMCID: PMC3335255 DOI: 10.1155/2012/416927] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 01/02/2012] [Accepted: 01/02/2012] [Indexed: 11/17/2022]
Abstract
mTOR/S6K pathway is a crucial regulator of cell growth and metabolism. Deregulated signalling via S6K has been linked to various human pathologies, including metabolic disorders and cancer. Many of the molecules signalling upstream of S6K have been shown to be either mutated or overexpressed in tumours, leading to S6K activation. The role of S6K1 in brain tumours is not fully investigated. In this study, we investigated the gene expression profile of S6 kinases in brain and CNS tumours using the publically available Cancer Microarray Database. We found that S6K1 but not S6K2 gene is overexpressed in brain tumours and this upregulation is associated with patients' poor survival. Furthermore, we interrogated Oncomine database for the expression profile of hypoxia-induced genes using a literature-defined concept. This gene list included HIF1A, VEGFA, SOX4, SOX9, MMP2, and NEDD9. We show that those genes are upregulated in all brain tumour studies investigated. Additionally, we analysed the coexpression profile of S6K1 and hypoxia responsive genes. The analysis was done across 4 different brain studies and showed that S6K1 is co-overexpressed with several hypoxia responsive genes. This study highlights the possible role of S6K1 in brain tumour progression and prediction of patients' survival. However, new epidemiological studies should be conducted in order to confirm these associations and to refine the role of S6K1 in brain tumours as a useful marker for patients' survival.
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Pópulo H, Lopes JM, Soares P. The mTOR signalling pathway in human cancer. Int J Mol Sci 2012; 13:1886-1918. [PMID: 22408430 PMCID: PMC3291999 DOI: 10.3390/ijms13021886] [Citation(s) in RCA: 560] [Impact Index Per Article: 46.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 01/28/2012] [Accepted: 01/30/2012] [Indexed: 01/20/2023] Open
Abstract
The conserved serine/threonine kinase mTOR (the mammalian target of rapamycin), a downstream effector of the PI3K/AKT pathway, forms two distinct multiprotein complexes: mTORC1 and mTORC2. mTORC1 is sensitive to rapamycin, activates S6K1 and 4EBP1, which are involved in mRNA translation. It is activated by diverse stimuli, such as growth factors, nutrients, energy and stress signals, and essential signalling pathways, such as PI3K, MAPK and AMPK, in order to control cell growth, proliferation and survival. mTORC2 is considered resistant to rapamycin and is generally insensitive to nutrients and energy signals. It activates PKC-α and AKT and regulates the actin cytoskeleton. Deregulation of multiple elements of the mTOR pathway (PI3K amplification/mutation, PTEN loss of function, AKT overexpression, and S6K1, 4EBP1 and eIF4E overexpression) has been reported in many types of cancers, particularly in melanoma, where alterations in major components of the mTOR pathway were reported to have significant effects on tumour progression. Therefore, mTOR is an appealing therapeutic target and mTOR inhibitors, including the rapamycin analogues deforolimus, everolimus and temsirolimus, are submitted to clinical trials for treating multiple cancers, alone or in combination with inhibitors of other pathways. Importantly, temsirolimus and everolimus were recently approved by the FDA for the treatment of renal cell carcinoma, PNET and giant cell astrocytoma. Small molecules that inhibit mTOR kinase activity and dual PI3K-mTOR inhibitors are also being developed. In this review, we aim to survey relevant research, the molecular mechanisms of signalling, including upstream activation and downstream effectors, and the role of mTOR in cancer, mainly in melanoma.
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Affiliation(s)
- Helena Pópulo
- Institute of Molecular Pathology and Immunology of University of Porto (IPATIMUP), University of Porto, 4200-465, Porto, Portugal; E-Mails: (H.P.); (J.M.L.)
- Medical Faculty, University of Porto, 4200-465 Porto, Portugal
| | - José Manuel Lopes
- Institute of Molecular Pathology and Immunology of University of Porto (IPATIMUP), University of Porto, 4200-465, Porto, Portugal; E-Mails: (H.P.); (J.M.L.)
- Medical Faculty, University of Porto, 4200-465 Porto, Portugal
- Department of Pathology, Hospital São João, 4200-465 Porto, Portugal
| | - Paula Soares
- Institute of Molecular Pathology and Immunology of University of Porto (IPATIMUP), University of Porto, 4200-465, Porto, Portugal; E-Mails: (H.P.); (J.M.L.)
- Medical Faculty, University of Porto, 4200-465 Porto, Portugal
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Chen SM, Liu JL, Wang X, Liang C, Ding J, Meng LH. Inhibition of tumor cell growth, proliferation and migration by X-387, a novel active-site inhibitor of mTOR. Biochem Pharmacol 2012; 83:1183-94. [PMID: 22305748 DOI: 10.1016/j.bcp.2012.01.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 01/14/2012] [Accepted: 01/17/2012] [Indexed: 12/22/2022]
Abstract
The mammalian target of rapamycin (mTOR), is deregulated in about 50% of human malignancies and exists in two complexes: mTORC1 and mTORC2. Rapalogs partially inhibit mTORC1 through allosteric binding to mTORC1 and their efficacy is modest as a cancer therapy. A few mTOR kinase inhibitors that inhibit both mTORC1 and mTORC2 have been reported to possess potent anticancer activities. Herein, we designed and synthesized a series of pyrazolopyrimidine derivatives targeting mTOR kinase domain and X-387 was identified as a promising lead. X-387 selectively inhibited mTOR in an ATP-competitive manner while sparing a panel of kinases from the PIKK family. X-387 blocked mTORC1 and mTORC2-mediacted signaling pathway in cell lines with activated mTOR signaling and in rapamycin-resistant cells. Specifically, X-387 inhibited phosphorylation of AKT at T308, which is thought to be a target of PDK1 but not mTOR. Such activity was not due to inhibition of PI3K since X-387 did not inhibit translocation of AKT to the cell membrane. X-387 induced autophagy as observed for other mTOR inhibitors, while induced autophagy is pro-survival since concurrent inhibition of autophagy by 3-MA reinforced the antiproliferative activity of mTOR inhibitors. X-387 also inhibited cell motility, which is associated with decrease in activity of small GTPases such as RhoA, Rac1 and Cdc42. Taken together, X-387 is a promising compound lead targeting mTOR and with a wide spectrum anticancer activity among tumor cell lines. The data also underscores the complexity of the mTOR signaling pathways which are far from being understood.
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Affiliation(s)
- Si-meng Chen
- Division of Anti-tumor Pharmacology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai, PR China
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Glycogen synthase kinase (GSK)-3 promotes p70 ribosomal protein S6 kinase (p70S6K) activity and cell proliferation. Proc Natl Acad Sci U S A 2011; 108:E1204-13. [PMID: 22065737 DOI: 10.1073/pnas.1110195108] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The p70 ribosomal protein S6 kinase 1 (S6K1) plays a key role in cell growth and proliferation by regulating insulin sensitivity, metabolism, protein synthesis, and cell cycle. Thus, deregulation of S6K contributes to the progression of type 2 diabetes, obesity, aging, and cancer. Considering the biological and clinical importance of S6K1, a complete understanding of its regulation is critical. One of the key motifs in the activation of S6K1 is a turn motif, but its regulation is not well understood. Here we provide evidence for two mechanisms of modulating turn motif phosphorylation and S6K1 activity. First, mammalian target of rapamycin regulates turn motif phosphorylation by inhibiting its dephosphorylation. Second, we unexpectedly found that glycogen synthase kinase (GSK)-3 promotes turn motif phosphorylation. Our studies show that mammalian target of rapamycin and GSK-3 cooperate to control the activity of S6K1, an important regulator of cell proliferation and growth. Our unexpected results provide a clear rationale for the development and use of drugs targeting GSK-3 to treat diseases such as diabetes, cancer, and age-related diseases that are linked to improper regulation of S6K1.
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Streicher KL, Zhu W, Lehmann KP, Georgantas RW, Morehouse CA, Brohawn P, Carrasco RA, Xiao Z, Tice DA, Higgs BW, Richman L, Jallal B, Ranade K, Yao Y. A novel oncogenic role for the miRNA-506-514 cluster in initiating melanocyte transformation and promoting melanoma growth. Oncogene 2011; 31:1558-70. [PMID: 21860416 DOI: 10.1038/onc.2011.345] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Malignant melanoma is the most aggressive form of skin cancer and its incidence has doubled in the last two decades. It represents only 4% of skin cancer cases per year, but causes as many as 74% of skin cancer deaths. Early detection of malignant melanoma is associated with survival rates of up to 90%, but later detection (stage III to stage IV) is associated with survival rates of only 10%. Dysregulation of microRNA (miRNA) expression has been linked to tumor development and progression by functioning either as a tumor suppressor, an oncogene or a metastasis regulator in multiple cancer types. To understand the role of miRNA in the pathogenesis of malignant melanoma and identify biomarkers of metastasis, miRNA expression profiles in skin punches from 33 metastatic melanoma patients and 14 normal healthy donors were compared. We identified a cluster of 14 miRNAs on the X chromosome, termed the miR-506-514 cluster, which was consistently overexpressed in nearly all melanomas tested (30-60 fold, P<0.001), regardless of mutations in N-ras or B-raf. Inhibition of the expression of this cluster as a whole, or one of its sub-clusters (Sub-cluster A) consisting of six mature miRNAs, led to significant inhibition of cell growth, induction of apoptosis, decreased invasiveness and decreased colony formation in soft agar across multiple melanoma cell lines. Sub-cluster A of the miR-506-514 cluster was critical for maintaining the cancer phenotype, but the overexpression of the full cluster was necessary for melanocyte transformation. Our results provide new insights into the functional role of this miRNA cluster in melanoma, and suggest new approaches to treat or diagnose this disease.
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Affiliation(s)
- K L Streicher
- Department of Translational Sciences, MedImmune LLC, Gaithersburg, MD 20878, USA.
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Abstract
Notorious for its poor prognosis and aggressive nature, triple-negative breast cancer (TNBC) is a heterogeneous disease entity. The nature of its biological specificity, which is similar to basal-like cancers, tumors arising in BRCA1 mutation carriers, and claudin-low cancers, is currently being explored in hopes of finding the targets for novel biologics and chemotherapeutic agents. In this review, we aim to give a broad overview of the disease's nomenclature and epidemiology, as well as the basic mechanisms of emerging targeted therapies and their performance in clinical trials to date.
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Affiliation(s)
- Christina A. Minami
- David Geffen School of Medicine, The University of California at Los Angeles, Los Angeles, California, USA
| | - Debra U. Chung
- Clinical Trials Unit, Revlon/UCLA Breast Center, David Geffen School of Medicine, The University of California at Los Angeles, Los Angeles, California, USA
| | - Helena R. Chang
- David Geffen School of Medicine, The University of California at Los Angeles, Los Angeles, California, USA
- Department of Surgery, Revlon/UCLA Breast Center, David Geffen School of Medicine, The University of California at Los Angeles, Los Angeles, California, USA
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Sick E, Boukhari A, Deramaudt T, Rondé P, Bucher B, André P, Gies JP, Takeda K. Activation of CD47 receptors causes proliferation of human astrocytoma but not normal astrocytes via an Akt-dependent pathway. Glia 2011; 59:308-19. [PMID: 21125662 DOI: 10.1002/glia.21102] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
CD47 is a membrane receptor that plays pivotal roles in many pathophysiological processes, including infection, inflammation, cell spreading, proliferation, and apoptosis. We show that activation of CD47 increases proliferation of human U87 and U373 astrocytoma cells but not normal astrocytes. CD47 function-blocking antibodies inhibit proliferation of untreated U87 and U373 cells but not normal astrocytes, suggesting that CD47 may be constitutively activated in astrocytoma. CD47 expression levels were similar in our three cell types. CD47 couples to G-proteins in astrocytes and astrocytoma and especially to the Gβγ dimer. Downstream signaling following CD47 activation involves Gβγ dimer-dependent activation of the PI3K/Akt pathway in astrocytoma cells but not in normal astrocytes. This pathway is known to be deregulated in astrocytoma, leading to cell proliferation and enhanced survival signals. Putative PLIC-1 interaction with CD47 in astrocytoma cells but not astrocytes may contribute to the proliferative effect observed upon activation of CD47. Our data indicate that CD47 receptors have a stimulatory role in cell proliferation and demonstrate for the first time that CD47 signals via the PI3K/Akt pathway in cancerous cells but not normal cells.
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Affiliation(s)
- Emilie Sick
- Université de Strasbourg, CNRS UMR 7213-Pharmacologie, Faculté de Pharmacie, 74 rte du Rhin, Illkirch, France.
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38
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Theurillat JP, Metzler SC, Henzi N, Djouder N, Helbling M, Zimmermann AK, Jacob F, Soltermann A, Caduff R, Heinzelmann-Schwarz V, Moch H, Krek W. URI is an oncogene amplified in ovarian cancer cells and is required for their survival. Cancer Cell 2011; 19:317-32. [PMID: 21397856 DOI: 10.1016/j.ccr.2011.01.019] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Revised: 11/09/2010] [Accepted: 01/07/2011] [Indexed: 11/25/2022]
Abstract
Abrogation of negative feedback control represents a fundamental requirement for aberrantly activated signaling pathways to promote malignant transformation and resistance to therapy. Here we identify URI, which encodes a mitochondrial inhibitor of PP1γ and PP1γ-mediated feedback inhibition of S6K1-BAD survival signaling, as an oncogene amplified and overexpressed in ovarian cancer cell lines and human ovarian carcinomas. URI is an "addicting" oncogene selectively required for the survival of ovarian cancer cells with increased URI copy number. By constitutively detaining PP1γ in inactive complexes, URI sustains S6K1 survival signaling under growth factor-limiting conditions and mediates resistance of cells to cisplatin. Thus, oncogenic activation of URI defines an important mechanism for activating mitochondrial S6K1-BAD signaling and promoting cell survival through disabling PP1γ-dependent negative feedback inhibition.
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39
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Ribosomal protein S6 is highly expressed in non-Hodgkin lymphoma and associates with mRNA containing a 5' terminal oligopyrimidine tract. Oncogene 2010; 30:1531-41. [PMID: 21102526 DOI: 10.1038/onc.2010.533] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The molecular mechanism(s) linking tumorigenesis and morphological alterations in the nucleolus are presently coming into focus. The nucleolus is the cellular organelle in which the formation of ribosomal subunits occurs. Ribosomal biogenesis occurs through the transcription of ribosomal RNA (rRNA), rRNA processing and production of ribosomal proteins. An error in any of these processes may lead to deregulated cellular translation, evident in multiple cancers and 'ribosomopathies'. Deregulated protein synthesis may be achieved through the overexpression of ribosomal proteins as seen in primary leukemic blasts with elevated levels of ribosomal proteins S11 and S14. In this study, we demonstrate that ribosomal protein S6 (RPS6) is highly expressed in primary diffuse large B-cell lymphoma (DLBCL) samples. Genetic modulation of RPS6 protein levels with specifically targeted short hairpin RNA (shRNA) lentiviruses led to a decrease in the actively proliferating population of cells compared with control shRNA. Low-dose rapamycin treatments have been shown to affect the translation of 5' terminal oligopyrimidine (5' TOP) tract mRNA, which encodes the translational machinery, implicating RPS6 in 5' TOP translation. Recently, it was shown that disruption of 40S ribosomal biogenesis through specific small inhibitory RNA knockdown of RPS6 defined RPS6 as a critical regulator of 5' TOP translation. For the first time, we show that RPS6 associates with multiple mRNAs containing a 5' TOP tract. These findings expand our understanding of the mechanism(s) involved in ribosomal biogenesis and deregulated protein synthesis in DLBCL.
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40
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McAuliffe PF, Meric-Bernstam F, Mills GB, Gonzalez-Angulo AM. Deciphering the role of PI3K/Akt/mTOR pathway in breast cancer biology and pathogenesis. Clin Breast Cancer 2010; 10 Suppl 3:S59-65. [PMID: 21115423 DOI: 10.3816/cbc.2010.s.013] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway mediates multiple cellular functions critical to tumor initiation, progression, and outcomes, including growth and proliferation, metabolism, motility, migration, invasion, angiogenesis, survival, and autophagy. Tight regulation of this pathway is paramount to ensure that multiple cellular inputs are integrated for appropriate cellular outcomes. Frequent deregulation and aberrations of this pathway have been implicated in breast cancer development and progression. This review focuses on the biology of this pathway and its role in breast cancer pathogenesis. The role of therapies directed at targeting mTOR in the PI3K/Akt/mTOR pathway, which are currently being evaluated in clinical trials, will also be reviewed.
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Affiliation(s)
- Priscilla F McAuliffe
- Departments of Surgical Oncology, The University of Texas, MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
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41
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Fenton TR, Gout IT. Functions and regulation of the 70kDa ribosomal S6 kinases. Int J Biochem Cell Biol 2010; 43:47-59. [PMID: 20932932 DOI: 10.1016/j.biocel.2010.09.018] [Citation(s) in RCA: 250] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Revised: 09/17/2010] [Accepted: 09/23/2010] [Indexed: 01/01/2023]
Abstract
The 70kDa ribosomal protein S6 kinases, S6K1 and S6K2 are two highly homologous serine/threonine kinases that are activated in response to growth factors, cytokines and nutrients. The S6 kinases have been linked to diverse cellular processes, including protein synthesis, mRNA processing, glucose homeostasis, cell growth and survival. Studies in model organisms have highlighted the roles that S6K activity plays in a number of pathologies, including obesity, diabetes, ageing and cancer. The importance of S6K function in human diseases has led to the development of S6K-specific inhibitors by a number of companies, offering the promise of improved tools with which to study these enzymes and potentially the effective targeting of deregulated S6K signalling in patients. Here we review the current literature on the role of S6Ks in the regulation of cell growth, survival and proliferation downstream of various signalling pathways and how their dysregulation contributes to the pathogenesis of human diseases.
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Affiliation(s)
- Tim R Fenton
- Ludwig Institute for Cancer Research, University of California San Diego, 9500 Gilman Dr, La Jolla, CA 92093-0660, USA
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42
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Akhavan D, Cloughesy TF, Mischel PS. mTOR signaling in glioblastoma: lessons learned from bench to bedside. Neuro Oncol 2010; 12:882-9. [PMID: 20472883 PMCID: PMC2940679 DOI: 10.1093/neuonc/noq052] [Citation(s) in RCA: 131] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Phosphatidyl-inositol-3 kinases (PI3Ks) constitute a family of intracellular lipid kinases that are frequently hyperactivated in glioblastoma. The PI3K complex links growth factor signaling with cellular proliferation, differentiation, metabolism, and survival. Mammalian target of rapamycin (mTOR) acts both as a downstream effector and upstream regulator of PI3K, thus highlighting its importance in glioblastoma. This review highlights laboratory and clinical evidence of mTOR's role in glioblastoma. Mechanisms of escape from mTOR inhibition are also discussed, as well as future clinical strategies of mTOR inhibition.
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Affiliation(s)
- David Akhavan
- The David Geffen UCLA School of Medicine, 10833 Le Conte Avenue, Los Angeles, CA 90095-1732, USA
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43
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Abstract
Remarkable progress has been made in defining a new understanding of the role of mRNA translation and protein synthesis in human cancer. Translational control is a crucial component of cancer development and progression, directing both global control of protein synthesis and selective translation of specific mRNAs that promote tumour cell survival, angiogenesis, transformation, invasion and metastasis. Translational control of cancer is multifaceted, involving alterations in translation factor levels and activities unique to different types of cancers, disease stages and the tumour microenvironment. Several clinical efforts are underway to target specific components of the translation apparatus or unique mRNA translation elements for cancer therapeutics.
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44
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Targeting the translational machinery as a novel treatment strategy for hematologic malignancies. Blood 2010; 115:2127-35. [PMID: 20075156 DOI: 10.1182/blood-2009-09-220020] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The dysregulation of protein synthesis evident in the transformed phenotype has opened up a burgeoning field of research in cancer biology. Translation initiation has recently been shown to be a common downstream target of signal transduction pathways deregulated in cancer and initiated by mutated/overexpressed oncogenes and tumor suppressors. The overexpression and/or activation of proteins involved in translation initiation such as eIF4E, mTOR, and eIF4G have been shown to induce a malignant phenotype. Therefore, understanding the mechanisms that control protein synthesis is emerging as an exciting new research area with significant potential for developing innovative therapies. This review highlights molecules that are activated or dysregulated in hematologic malignancies, and promotes the transformed phenotype through the deregulation of protein synthesis. Targeting these proteins with small molecule inhibitors may constitute a novel therapeutic approach in the treatment of cancer.
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45
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Cuesta R, Gupta M, Schneider RJ. The regulation of protein synthesis in cancer. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2009; 90:255-92. [PMID: 20374744 DOI: 10.1016/s1877-1173(09)90007-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Translational control of cancer is a multifaceted process, involving alterations in translation factor levels and activities that are unique to the different types of cancers and the different stages of disease. Translational alterations in cancer include adaptations of the tumor itself, of the tumor microenvironment, an integral component in disease, and adaptations that occur as cancer progresses from development to local disease and ultimately to metastatic disease. Adaptations include the overexpression and increased activity of specific translation factors, the physical or functional loss of translation regulatory components, increased production of ribosomes, selective mRNA translation, and alteration of signal transduction pathways to permit unfettered activation of protein synthesis. There is intense clinical interest to capitalize on the emerging new understanding of translational control in cancer by targeting specific components of the translation apparatus that are altered in disease for the development of specific cancer therapeutics. Clinical trial data are nascent but encouraging, suggesting that translational control constitutes an important new area for drug development in human cancer.
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Affiliation(s)
- Rafael Cuesta
- Department of Microbiology, New York University School of Medicine, New York, New York 10016, USA
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46
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The AMPK agonist AICAR inhibits the growth of EGFRvIII-expressing glioblastomas by inhibiting lipogenesis. Proc Natl Acad Sci U S A 2009; 106:12932-7. [PMID: 19625624 DOI: 10.1073/pnas.0906606106] [Citation(s) in RCA: 183] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The EGFR/PI3K/Akt/mTOR signaling pathway is activated in many cancers including glioblastoma, yet mTOR inhibitors have largely failed to show efficacy in the clinic. Rapamycin promotes feedback activation of Akt in some patients, potentially underlying clinical resistance and raising the need for alternative approaches to block mTOR signaling. AMPK is a metabolic checkpoint that integrates growth factor signaling with cellular metabolism, in part by negatively regulating mTOR. We used pharmacological and genetic approaches to determine whether AMPK activation could block glioblastoma growth and cellular metabolism, and we examined the contribution of EGFR signaling in determining response in vitro and in vivo. The AMPK-agonist AICAR, and activated AMPK adenovirus, inhibited mTOR signaling and blocked the growth of glioblastoma cells expressing the activated EGFR mutant, EGFRvIII. Across a spectrum of EGFR-activated cancer cell lines, AICAR was more effective than rapamycin at blocking tumor cell proliferation, despite less efficient inhibition of mTORC1 signaling. Unexpectedly, addition of the metabolic products of cholesterol and fatty acid synthesis rescued the growth inhibitory effect of AICAR, whereas inhibition of these lipogenic enzymes mimicked AMPK activation, thus demonstrating that AMPK blocked tumor cell proliferation primarily through inhibition of cholesterol and fatty acid synthesis. Most importantly, AICAR treatment in mice significantly inhibited the growth and glycolysis (as measured by (18)fluoro-2-deoxyglucose microPET) of glioblastoma xenografts engineered to express EGFRvIII, but not their parental counterparts. These results suggest a mechanism by which AICAR inhibits the proliferation of EGFRvIII expressing glioblastomas and point toward a potential therapeutic strategy for targeting EGFR-activated cancers.
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47
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Huang TT, Sarkaria SM, Cloughesy TF, Mischel PS. Targeted therapy for malignant glioma patients: lessons learned and the road ahead. Neurotherapeutics 2009; 6:500-12. [PMID: 19560740 PMCID: PMC3600166 DOI: 10.1016/j.nurt.2009.04.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Accepted: 04/24/2009] [Indexed: 10/20/2022] Open
Abstract
Molecularly targeted therapies are transforming the care of patients with malignant gliomas, including glioblastoma, the most common malignant primary brain tumor of adults. With an arsenal of small molecule inhibitors and antibodies that target key components of the signal transduction machinery that are commonly activated in gliomas, neuro-oncologists and neurosurgeons are poised to transform the care of these patients. Nonetheless, successful application of targeted therapies remains a challenge. Strategies are lacking for directing kinase inhibitor or other pathway-specific therapies to individual patients most likely to benefit. In addition, response to targeted agents is determined not only by the presence of the key mutant kinases, but also by other critical changes in the molecular circuitry of cancer cells, such as loss of key tumor suppressor proteins, the selection for kinase-resistant mutants, and the deregulation of feedback loops. Understanding these signaling networks, and studying them in patients, will be critical for developing rational combination therapies to suppress resistance for malignant glioma patients. Here we review the current status of molecular targeted therapies for malignant gliomas. We focus initially on identifying some of the insights gained to date from targeting the EGFR/PI3K/Akt/mTOR signaling pathway in patients and on how this has led toward a reconceptualization of some of the challenges and directions for targeted treatment. We describe how advances from the world of genomics have the potential to transform our approaches toward targeted therapy, and describe how a deeper understanding of the complex nature of cancer, and its adeptness at rewiring molecular circuitry to evade targeted agents, has raised new challenges and identified new leads.
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Affiliation(s)
- Tiffany T. Huang
- grid.19006.3e0000000096326718Department of Pathology and Laboratory Medicine and Molecular & Medical Pharmacology, University of California, Los Angeles, 90095 Los Angeles, California
| | - Shawn M. Sarkaria
- grid.19006.3e0000000096326718Department of Pathology and Laboratory Medicine and Molecular & Medical Pharmacology, University of California, Los Angeles, 90095 Los Angeles, California
| | - Timothy F. Cloughesy
- grid.19006.3e0000000096326718Department of Neurology, University of California, Los Angeles, 90095 Los Angeles, California
- grid.19006.3e0000000096326718Henry E. Singleton Brain Tumor Program, David Geffen School of Medicine, University of California, Los Angeles, 90095 Los Angeles, California
| | - Paul S. Mischel
- grid.19006.3e0000000096326718Department of Pathology and Laboratory Medicine and Molecular & Medical Pharmacology, University of California, Los Angeles, 90095 Los Angeles, California
- grid.19006.3e0000000096326718Henry E. Singleton Brain Tumor Program, David Geffen School of Medicine, University of California, Los Angeles, 90095 Los Angeles, California
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Narayanan SP, Flores AI, Wang F, Macklin WB. Akt signals through the mammalian target of rapamycin pathway to regulate CNS myelination. J Neurosci 2009; 29:6860-70. [PMID: 19474313 PMCID: PMC2757755 DOI: 10.1523/jneurosci.0232-09.2009] [Citation(s) in RCA: 257] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Mammalian target of rapamycin (mTOR), a well known Akt substrate, regulates multiple cellular functions including cell growth and protein synthesis. The current study identifies a novel role of the Akt/mTOR pathway as a regulator of CNS myelination. Previously, we showed that overexpressing constitutively active Akt in oligodendrocytes in a transgenic mouse model induces enhanced CNS myelination, with no changes in the proliferation or survival of oligodendrocyte progenitor or mature cells. The present study focused on the signaling mechanisms regulating this hypermyelination induced by Akt. Activation of mTOR and its downstream substrates (p70S6 kinase and S6 ribosomal protein) was observed in Akt-overexpressing oligodendrocytes. When mTOR signaling was inhibited chronically in vivo with rapamycin starting at 6 weeks of age, the observed hypermyelination was reduced to approximately the amount of myelin seen in wild-type mice. mTOR inhibition had little impact on wild-type myelination between 6 and 12 weeks of age, suggesting that, in normal adults, myelination is relatively complete and is no longer regulated by mTOR signaling. However, when mTOR was chronically inhibited in young adult wild-type mice, myelination was reduced. These results suggest that, during active myelination, the major Akt signal regulating CNS myelination is the mTOR pathway.
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Affiliation(s)
| | - Ana I. Flores
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Feng Wang
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Wendy B. Macklin
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
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Meric-Bernstam F, Gonzalez-Angulo AM. Targeting the mTOR signaling network for cancer therapy. J Clin Oncol 2009; 27:2278-87. [PMID: 19332717 PMCID: PMC2738634 DOI: 10.1200/jco.2008.20.0766] [Citation(s) in RCA: 508] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Accepted: 01/21/2009] [Indexed: 12/21/2022] Open
Abstract
The serine-threonine kinase mammalian target of rapamycin (mTOR) plays a major role in the regulation of protein translation, cell growth, and metabolism. Alterations of the mTOR signaling pathway are common in cancer, and thus mTOR is being actively pursued as a therapeutic target. Rapamycin and its analogs (rapalogs) have proven effective as anticancer agents in a broad range of preclinical models. Clinical trials using rapalogs have demonstrated important clinical benefits in several cancer types; however, objective response rates achieved with single-agent therapy have been modest. Rapalogs may be more effective in combination with other anticancer agents, including chemotherapy and targeted therapies. It is increasingly apparent that the mTOR signaling network is quite complex, and rapamycin treatment leads to different signaling responses in different cell types. A better understanding of mTOR signaling, the mechanism of action of rapamycin, and the identification of biomarkers of response will lead to more optimal targeting of this pathway for cancer therapy.
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Affiliation(s)
- Funda Meric-Bernstam
- Department of Surgical Oncology, Unit 444, The University of Texas M D Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA.
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