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Bouyahya A, El Allam A, Aboulaghras S, Bakrim S, El Menyiy N, Alshahrani MM, Al Awadh AA, Benali T, Lee LH, El Omari N, Goh KW, Ming LC, Mubarak MS. Targeting mTOR as a Cancer Therapy: Recent Advances in Natural Bioactive Compounds and Immunotherapy. Cancers (Basel) 2022; 14:5520. [PMID: 36428613 PMCID: PMC9688668 DOI: 10.3390/cancers14225520] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/01/2022] [Accepted: 11/02/2022] [Indexed: 11/12/2022] Open
Abstract
The mammalian target of rapamycin (mTOR) is a highly conserved serine/threonine-protein kinase, which regulates many biological processes related to metabolism, cancer, immune function, and aging. It is an essential protein kinase that belongs to the phosphoinositide-3-kinase (PI3K) family and has two known signaling complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). Even though mTOR signaling plays a critical role in promoting mitochondria-related protein synthesis, suppressing the catabolic process of autophagy, contributing to lipid metabolism, engaging in ribosome formation, and acting as a critical regulator of mRNA translation, it remains one of the significant signaling systems involved in the tumor process, particularly in apoptosis, cell cycle, and cancer cell proliferation. Therefore, the mTOR signaling system could be suggested as a cancer biomarker, and its targeting is important in anti-tumor therapy research. Indeed, its dysregulation is involved in different types of cancers such as colon, neck, cervical, head, lung, breast, reproductive, and bone cancers, as well as nasopharyngeal carcinoma. Moreover, recent investigations showed that targeting mTOR could be considered as cancer therapy. Accordingly, this review presents an overview of recent developments associated with the mTOR signaling pathway and its molecular involvement in various human cancer types. It also summarizes the research progress of different mTOR inhibitors, including natural and synthetised compounds and their main mechanisms, as well as the rational combinations with immunotherapies.
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Affiliation(s)
- Abdelhakim Bouyahya
- Laboratory of Human Pathologies Biology, Department of Biology, Faculty of Sciences, Faculty of Medicine and Pharmacy, Mohammed V University in Rabat, Rabat 10106, Morocco
| | - Aicha El Allam
- Department of Immunology, Yale University School of Medicine, 333 Cedars Street, TAC S610, New Haven, CT 06519, USA
| | - Sara Aboulaghras
- Physiology and Physiopathology Team, Faculty of Sciences, Genomic of Human Pathologies Research, Mohammed V University in Rabat, Rabat 10106, Morocco
| | - Saad Bakrim
- Geo-Bio-Environment Engineering and Innovation Laboratory, Molecular Engineering, Biotechnologies and Innovation Team, Polydisciplinary Faculty of Taroudant, Ibn Zohr University, Agadir 80000, Morocco
| | - Naoual El Menyiy
- Laboratory of Pharmacology, National Agency of Medicinal and Aromatic Plants, Taounate 34025, Morocco
| | - Mohammed Merae Alshahrani
- Department of Clinical Laboratory Sciences, Faculty of Applied Medical Sciences, Najran University, 1988, Najran 61441, Saudi Arabia
| | - Ahmed Abdullah Al Awadh
- Department of Clinical Laboratory Sciences, Faculty of Applied Medical Sciences, Najran University, 1988, Najran 61441, Saudi Arabia
| | - Taoufiq Benali
- Environment and Health Team, Polydisciplinary Faculty of Safi, Cadi Ayyad University, Sidi Bouzid B.P. 4162, Morocco
| | - Learn-Han Lee
- Novel Bacteria and Drug Discovery Research Group (NBDD), Microbiome and Bioresource Research Strength (MBRS), Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway 47500, Malaysia
| | - Nasreddine El Omari
- Laboratory of Histology, Embryology, and Cytogenetic, Faculty of Medicine and Pharmacy, Mohammed V University, Rabat 10100, Morocco
| | - Khang Wen Goh
- Faculty of Data Science and Information Technology, INTI International University, Nilai 71800, Malaysia
| | - Long Chiau Ming
- Pengiran Anak Puteri Rashidah Sa’adatul Bolkiah Institute of Health Sciences, Universiti Brunei Darussalam, Gadong BE1410, Brunei
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Lv X, Xu J, Jiang J, Wu P, Tan R, Wang B. Genetic animal models of scoliosis: A systematical review. Bone 2021; 152:116075. [PMID: 34174503 DOI: 10.1016/j.bone.2021.116075] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 06/16/2021] [Accepted: 06/17/2021] [Indexed: 02/07/2023]
Abstract
Scoliosis is a complex disease with undetermined pathogenesis and has a strong relationship with genetics. Models of scoliosis in animals have been established for better comprehending its pathogenesis and treatment. In this review, we searched all the genetic animal models with body curvature in databases, and reviewed the related genes and scoliosis types. Meanwhile, we also summarized the pathogenesis of scoliosis reported so far. Summarizing the positive phenotypic animal models contributes to a better understanding on the pathogenesis of scoliosis and facilitates the selection of experimental models when a possible pathogenic factor is concerned.
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Affiliation(s)
- Xin Lv
- Department of Spine Surgery, The Second Xiangya Hospital, Central South University, Changsha 410011, Hunan, China
| | - Jinghong Xu
- Department of Spine Surgery, The Second Xiangya Hospital, Central South University, Changsha 410011, Hunan, China
| | - Jiajiong Jiang
- Department of Spine Surgery, The Second Xiangya Hospital, Central South University, Changsha 410011, Hunan, China
| | - Pengfei Wu
- Department of Spine Surgery, The Second Xiangya Hospital, Central South University, Changsha 410011, Hunan, China
| | - Renchun Tan
- Department of Spine Surgery, The Second Xiangya Hospital, Central South University, Changsha 410011, Hunan, China
| | - Bing Wang
- Department of Spine Surgery, The Second Xiangya Hospital, Central South University, Changsha 410011, Hunan, China.
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Tian Y, Chen J, Yan X, Ren D, Liu M, Zhang Q, Zhang Q, Yuan X. Overloaded Orthopedic Force Induces Condylar Subchondral Bone Absorption by Stimulating Rat Mesenchymal Stem Cells Differentiating into Osteoclasts via mTOR-Regulated RANKL/OPG Secretion in Osteoblasts. Stem Cells Dev 2021; 30:29-38. [PMID: 33176606 DOI: 10.1089/scd.2020.0163] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Appropriate orthopedic force led to bone remodeling of mandibular condyle, while overloaded orthopedic force (OOF) induced condylar bone absorption. Bone absorption is ascribed to the imbalanced activities between osteoclasts (OCs) and osteoblasts (OBs), mechanism of which remains unclear. This study aimed to observe the condylar changes induced by OOF by mandible advancement appliance and to further investigate the role of mammalian target of Rapamycin (mTOR) and RANKL/OPG in osteoclastic differentiation of stem cells in vivo and in vitro. In vivo, the results of micro-CT analysis indicated that condylar bone resorption was induced by OOF through mandibular advancement appliance for 2 weeks and worsened time dependently. Morphologically, cartilage thickness was reduced, subchondral cortical bone line appeared not continuous, and subchondral bone exhibited irregular-shaped and owned uneven surface. The bone mineral density (BMD), bone volume/tissue volume (BV/TV), trabecular number (Tb.N), and trabecular thickness (Tb.Th) were decreased accomplished with the increased trabecular separation (Tb.Sp) determined by micro-CT. In addition, based on immunofluorescent labeling, OOF activated both OCs and OBs, but osteoclastogenesis prevailed over osteogenesis. The mTOR activation and ratio of RANKL/OPG in OBs were elevated by OOF. In vitro, the results of western blot and polymerase chain reaction (PCR) consistently suggested that the mTOR and RANKL/OPG ratio were upregulated by overloaded mechanical stretch. Pretreatment with mTOR inhibitor, rapamycin, could attenuate the activation of mTOR and the secretion of RANKL in OBs. Interestingly, based on the Trap staining, the supernatant of OBs exposed to OOF could promote osteoclastic differentiation of mesenchymal stem cells (MSCs), while its role was weakened by inhibition of mTOR in OBs. Collectively, OOF induced condylar bone absorption; in the process, osteoclastogenesis was prominent than osteogenesis. The activation of mTOR and secretion of RANKL/OPG were enhanced by OOF and were involved in promoting MSCs differentiating into OCs.
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Affiliation(s)
- Yihong Tian
- Department II of Orthodontics, Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China
- School of Stomatology, Qingdao University, Qingdao, People's Republic of China
| | - Junbo Chen
- Department II of Orthodontics, Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China
| | - Xiao Yan
- Department II of Orthodontics, Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China
| | - Dapeng Ren
- Department II of Orthodontics, Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China
| | - Meixi Liu
- Department II of Orthodontics, Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China
| | - Qi Zhang
- Department II of Orthodontics, Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China
| | - Qiang Zhang
- Department II of Orthodontics, Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China
| | - Xiao Yuan
- Department II of Orthodontics, Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China
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PAZARCI Ö, DOĞAN HO, KILINÇ S, ÇAMURCU Y. Does mammalian target of rapamycin or sestrin 1 protein signaling have a role in bone
fracture healing? Turk J Med Sci 2019; 49:1774-1778. [PMID: 31655537 PMCID: PMC7518658 DOI: 10.3906/sag-1809-117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 09/22/2019] [Indexed: 11/30/2022] Open
Abstract
Background/aim Fracture healing is a complex physiological process that involves a well-orchestrated series of biological events. The mammalian target of rapamycin (mTOR) and sestrin 1 (SESN 1) play a central role in cell metabolism, proliferation, and survival. The aim of our study is to present serum mTOR and SESN 1 levels by comparing patients with or without bone fractures. It is also a guide for further research on the roles of these proteins in fracture healing. Materials and methods A total of 34 patients (10 females, 24 males) with bone fractures and 32 controls (10 females, 22 males) participated in this study. After collecting serum venous blood samples, the quantitative sandwich ELISA technique was used for the determination of serum mTOR and SESN 1 levels. Results The mean serum mTOR level was significantly higher in the fracture group compared to the control group (P = 0.001). However, SESN 1 levels did not significantly differ between groups (P = 0.913). Conclusion We found that serum mTOR levels increased on the first day after fracture compared to the control group. However, we obtained no significant difference between groups in terms of SESN 1 levels. This study may guide further clinical studies investigating the potential role of mTOR signaling in the bone healing process.
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Affiliation(s)
- Özhan PAZARCI
- Department of Orthopedics and Traumatology, Faculty of Medicine, Cumhuriyet University, SivasTurkey
- * To whom correspondence should be addressed. E-mail:
| | - Halef Okan DOĞAN
- Department of Biochemistry, Faculty of Science, Cumhuriyet University, SivasTurkey
| | - Seyran KILINÇ
- Department of Orthopedics and Traumatology, Faculty of Medicine, Cumhuriyet University, SivasTurkey
| | - Yalkin ÇAMURCU
- Department of Orthopedics and Traumatology, Faculty of Medicine, Erzincan University, ErzincanTurkey
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Maiese K. Moving to the Rhythm with Clock (Circadian) Genes, Autophagy, mTOR, and SIRT1 in Degenerative Disease and Cancer. Curr Neurovasc Res 2018; 14:299-304. [PMID: 28721811 DOI: 10.2174/1567202614666170718092010] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 06/22/2017] [Accepted: 07/06/2017] [Indexed: 12/12/2022]
Abstract
BACKGROUND The mammalian circadian clock and its associated clock genes are increasingly been recognized as critical components for a number of physiological and disease processes that extend beyond hormone release, thermal regulation, and sleep-wake cycles. New evidence suggests that clinical behavior disruptions that involve prolonged shift work and even space travel may negatively impact circadian rhythm and lead to multi-system disease. METHODS In light of the significant role circadian rhythm can hold over the body's normal physiology as well as disease processes, we examined and discussed the impact circadian rhythm and clock genes hold over lifespan, neurodegenerative disorders, and tumorigenesis. RESULTS In experimental models, lifespan is significantly reduced with the introduction of arrhythmic mutants and leads to an increase in oxidative stress exposure. Interestingly, patients with Alzheimer's disease and Parkinson's disease may suffer disease onset or progression as a result of alterations in the DNA methylation of clock genes as well as prolonged pharmacological treatment for these disorders that may lead to impairment of circadian rhythm function. Tumorigenesis also can occur with the loss of a maintained circadian rhythm and lead to an increased risk for nasopharyngeal carcinoma, breast cancer, and metastatic colorectal cancer. Interestingly, the circadian clock system relies upon the regulation of the critical pathways of autophagy, the mechanistic target of rapamycin (mTOR), AMP activated protein kinase (AMPK), and silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1) as well as proliferative mechanisms that involve the wingless pathway of Wnt/β-catenin pathway to foster cell survival during injury and block tumor cell growth. CONCLUSION Future targeting of the pathways of autophagy, mTOR, SIRT1, and Wnt that control mammalian circadian rhythm may hold the key for the development of novel and effective therapies against aging- related disorders, neurodegenerative disease, and tumorigenesis.
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Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling, Newark, NY. United States
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Shen G, Ren H, Qiu T, Zhang Z, Zhao W, Yu X, Huang J, Tang J, Liang D, Yao Z, Yang Z, Jiang X. Mammalian target of rapamycin as a therapeutic target in osteoporosis. J Cell Physiol 2017; 233:3929-3944. [PMID: 28834576 DOI: 10.1002/jcp.26161] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 08/21/2017] [Indexed: 12/19/2022]
Abstract
The mechanistic target of rapamycin (mTOR) plays a key role in sensing and integrating large amounts of environmental cues to regulate organismal growth, homeostasis, and many major cellular processes. Recently, mounting evidences highlight its roles in regulating bone homeostasis, which sheds light on the pathogenesis of osteoporosis. The activation/inhibition of mTOR signaling is reported to positively/negatively regulate bone marrow mesenchymal stem cells (BMSCs)/osteoblasts-mediated bone formation, adipogenic differentiation, osteocytes homeostasis, and osteoclasts-mediated bone resorption, which result in the changes of bone homeostasis, thereby resulting in or protect against osteoporosis. Given the likely importance of mTOR signaling in the pathogenesis of osteoporosis, here we discuss the detailed mechanisms in mTOR machinery and its association with osteoporosis therapy.
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Affiliation(s)
- Gengyang Shen
- Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Hui Ren
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Ting Qiu
- Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Zhida Zhang
- Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Wenhua Zhao
- Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xiang Yu
- Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Jinjing Huang
- Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Jingjing Tang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - De Liang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Zhensong Yao
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Zhidong Yang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xiaobing Jiang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.,Laboratory Affiliated to National Key Discipline of Orthopaedic and Traumatology of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China
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Prasadam I, Batra J, Perry S, Gu W, Crawford R, Xiao Y. Systematic Identification, Characterization and Target Gene Analysis of microRNAs Involved in Osteoarthritis Subchondral Bone Pathogenesis. Calcif Tissue Int 2016; 99:43-55. [PMID: 26944279 DOI: 10.1007/s00223-016-0125-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 02/20/2016] [Indexed: 12/20/2022]
Abstract
This study aimed to identify the microRNAs associated with sclerotic status of subchondral bone in the pathogenesis of osteoarthritis (OA). Total RNA was extracted from non-sclerotic and sclerotic OA subchondral bone from patients undergoing knee replacement surgeries. miRCURY™ LNA miRNA chip and qRT-PCR were used to profile and validate differential microRNA expression. In addition, we further confirmed profiles of altered miRNAs in an OA rat meniscectomy animal model and their putative targets of the miRNAs were predicted using ingenuity (IPA) software. Finally, five short-listed miRNAs were reactivated by transient in vitro overexpression (miRNA mimics) in subchondral bone osteoblasts and their phenotypes were assessed. Functional screening identified 30 differentiated miRNAs in sclerotic subchondral bone compared to non-sclerotic bone of OA patients. Data integration resulted in confirmation of the eight miRNAs, with aberrant expression in independent human OA bone sample set. In silico analysis (IPA) identified 732 mRNA transcripts as putative targets of the eight altered miRNAs, of which twenty genes were validated to be differentially expressed in sclerotic compared to non-sclerotic bone samples. Out of eight dysregulated miRNA's, five of them showed consistent time-dependent downregulation in a rat OA model. Furthermore, synthetic miR-199a-3p, miR-199a-5p, miR-590-5p, and miR-211-5p mimics rescued the abnormal osteoarthritic subchondral bone osteoblast gene expression and mineralization. We have identified four novel miRNAs that play important roles in subchondral bone pathogenesis in OA. Additional studies are required to develop these miRNAs into therapeutic modalities for OA.
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Affiliation(s)
- Indira Prasadam
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, 4059, Australia.
| | - Jyotsna Batra
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, 4059, Australia
- Australian Prostate Cancer Research Centre, Translational Research Institute, Queensland University of Technology, Brisbane, Australia
| | - Samuel Perry
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, 4059, Australia
| | - Wenyi Gu
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia
| | - Ross Crawford
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, 4059, Australia
- Orthopaedic Department, Prince Charles Hospital, Brisbane, QLD, Australia
| | - Yin Xiao
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, 4059, Australia
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Abstract
In the context of breast cancer, the importance of the skeleton in the regulation of primary tumour development and as a site for subsequent metastasis is well characterized. Our understanding of the contributions made by the host bone and bone marrow cells increasingly demonstrates the extent of the interaction between tumour cells and normal host cells. As a result, the need to develop and utilize therapies that can impede the growth and/or function of tumour cells while sparing normal host bone and bone marrow cells is immense and expanding. The need for these new treatments is, however, superimposed on the orthopaedic management of patients' quality of life, where pain control and continued locomotion are paramount. Indeed, the majority of the anticancer therapies used to date often result in direct or indirect damage to bone. Thus, although the bone microenvironment regulates tumour cell growth in bone, cells within the bone marrow niche also mediate many of the orthopaedic consequences of tumour progression as well as resistance to the antitumour effects of existing therapies. In this Review, we highlight the effects of existing cancer treatments on bone and the bone marrow microenvironment as well as the mechanisms mediating these effects and the current utility of modern orthopaedic interventions.
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Affiliation(s)
- Issam Makhoul
- Department of Medicine, Division of Haematology/Oncology, Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72205, USA
| | - Corey O Montgomery
- Department of Orthopaedic Surgery, Centre for Orthopaedic Research, Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72205, USA
| | - Dana Gaddy
- Department of Physiology and Biophysics, Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72205, USA
| | - Larry J Suva
- Department of Orthopaedic Surgery, Centre for Orthopaedic Research, Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72205, USA
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Kaul A, Toonen JA, Cimino PJ, Gianino SM, Gutmann DH. Akt- or MEK-mediated mTOR inhibition suppresses Nf1 optic glioma growth. Neuro Oncol 2014; 17:843-53. [PMID: 25534823 DOI: 10.1093/neuonc/nou329] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Accepted: 11/08/2014] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Children with neurofibromatosis type 1 (NF1) develop optic pathway gliomas, which result from impaired NF1 protein regulation of Ras activity. One obstacle to the implementation of biologically targeted therapies is an incomplete understanding of the individual contributions of the downstream Ras effectors (mitogen-activated protein kinase kinase [MEK], Akt) to optic glioma maintenance. This study was designed to address the importance of MEK and Akt signaling to Nf1 optic glioma growth. METHODS Primary neonatal mouse astrocyte cultures were employed to determine the consequence of phosphatidylinositol-3 kinase (PI3K)/Akt and MEK inhibition on Nf1-deficient astrocyte growth. Nf1 optic glioma-bearing mice were used to assess the effect of Akt and MEK inhibition on tumor volume, proliferation, and retinal ganglion cell dysfunction. RESULTS Both MEK and Akt were hyperactivated in Nf1-deficient astrocytes in vitro and in Nf1 murine optic gliomas in vivo. Pharmacologic PI3K or Akt inhibition reduced Nf1-deficient astrocyte proliferation to wild-type levels, while PI3K inhibition decreased Nf1 optic glioma volume and proliferation. Akt inhibition of Nf1-deficient astrocyte and optic glioma growth reflected Akt-dependent activation of mammalian target of rapamycin (mTOR). Sustained MEK pharmacologic blockade also attenuated Nf1-deficient astrocytes as well as Nf1 optic glioma volume and proliferation. Importantly, these MEK inhibitory effects resulted from p90RSK-mediated, Akt-independent mTOR activation. Finally, both PI3K and MEK inhibition reduced optic glioma-associated retinal ganglion cell loss and nerve fiber layer thinning. CONCLUSION These findings establish that the convergence of 2 distinct Ras effector pathways on mTOR signaling maintains Nf1 mouse optic glioma growth, supporting the evaluation of pharmacologic inhibitors that target mTOR function in future human NF1-optic pathway glioma clinical trials.
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Affiliation(s)
- Aparna Kaul
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri (A.K., J.A.T., S.M.G., D.H.G.); Department of Pathology, Washington University School of Medicine, St. Louis, Missouri (P.J.C.)
| | - Joseph A Toonen
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri (A.K., J.A.T., S.M.G., D.H.G.); Department of Pathology, Washington University School of Medicine, St. Louis, Missouri (P.J.C.)
| | - Patrick J Cimino
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri (A.K., J.A.T., S.M.G., D.H.G.); Department of Pathology, Washington University School of Medicine, St. Louis, Missouri (P.J.C.)
| | - Scott M Gianino
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri (A.K., J.A.T., S.M.G., D.H.G.); Department of Pathology, Washington University School of Medicine, St. Louis, Missouri (P.J.C.)
| | - David H Gutmann
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri (A.K., J.A.T., S.M.G., D.H.G.); Department of Pathology, Washington University School of Medicine, St. Louis, Missouri (P.J.C.)
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Bertoldo F, Silvestris F, Ibrahim T, Cognetti F, Generali D, Ripamonti CI, Amadori D, Colleoni MA, Conte P, Del Mastro L, De Placido S, Ortega C, Santini D. Targeting bone metastatic cancer: Role of the mTOR pathway. Biochim Biophys Acta Rev Cancer 2014; 1845:248-54. [PMID: 24508774 DOI: 10.1016/j.bbcan.2014.01.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 01/22/2014] [Accepted: 01/28/2014] [Indexed: 12/14/2022]
Abstract
One of the great challenges of cancer medicine is to develop effective treatments for bone metastatic cancer. Most patients with advanced solid tumors will develop bone metastasis and will suffer from skeletal related events associated with this disease. Although some therapies are available to manage symptoms derived from bone metastases, an effective treatment has not been developed yet. The mammalian target of rapamycin (mTOR) pathway regulates cell growth and survival. Alterations in mTOR signaling have been associated with pathological malignancies, including bone metastatic cancer. Inhibition of mTOR signaling might therefore be a promising alternative for bone metastatic cancer management. This review summarizes the current knowledge on mTOR pathway signaling in bone tissue and provides an overview on the known effects of mTOR inhibition in bone cancer, both in in vitro and in vivo models.
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Affiliation(s)
| | - Franco Silvestris
- Department of Biomedical Sciences and Human Oncology, Section of Clinical Oncology, University of Bari 'A. Moro', Bari, Italy
| | - Toni Ibrahim
- Osteoncology and Rare Tumors Center, Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST) IRCCS, Meldola, Italy
| | | | - Daniele Generali
- UO Multidisciplinare di Patologia Mammaria, US Terapia Molecolare e Farmacogenomica, AZ. Istituti Ospitalieri di Cremona, Cremona, Italy
| | - Carla Ida Ripamonti
- Supportive Care in Cancer Unit, Department of Hematology and Pediatric Onco-Hematology, Fondazione IRCCS, Istituto Nazionale dei Tumori, Milan, Italy
| | - Dino Amadori
- Osteoncology and Rare Tumors Center, Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST) IRCCS, Meldola, Italy
| | | | - Pierfranco Conte
- Oncologia Medica 2, Istituto Oncologico Veneto IRCCS, Padova, Italy
| | - Lucia Del Mastro
- UO Sviluppo Terapie Innovative, IRCCS AOU San Martino, IST, National Institute for Cancer Research, Genoa, Italy
| | - Sabino De Placido
- Department of Endocrinology and Molecular and Clinical Oncology, University of Naples Federico II, Naples, Italy
| | | | - Daniele Santini
- Department of Medical Oncology, University Campus Bio-Medico, Rome, Italy.
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Neurofibroma-associated macrophages play roles in tumor growth and response to pharmacological inhibition. Acta Neuropathol 2013; 125:159-68. [PMID: 23099891 DOI: 10.1007/s00401-012-1056-7] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Accepted: 10/15/2012] [Indexed: 10/27/2022]
Abstract
Neurofibromatosis type 1 (NF1) is a common genetic disease that predisposes 30-50 % of affected individuals to develop plexiform neurofibromas. We found that macrophage infiltration of both mouse and human neurofibromas correlates with disease progression. Macrophages accounted for almost half of neurofibroma cells, leading us to hypothesize that nerve macrophages are inflammatory effectors in neurofibroma development and/or growth. We tested the effects of PLX3397, a dual kit/fms kinase inhibitor that blocks macrophage infiltration, in the Dhh-Cre; Nf1(flox/flox) mouse model of GEM grade I neurofibroma. In mice aged 1-4 months, prior to development of nerve pathology and neurofibroma formation, PLX3397 did not impair tumor initiation and increased tumor volume compared to controls. However, in mice aged 7-9 months, after tumor establishment, a subset of mice demonstrating the largest reductions in macrophages after PLX3397 exhibited cell death and tumor volume regression. Macrophages are likely to provide an initial line of defense against developing tumors. Once tumors are established, they become tumor permissive. Macrophage depletion may result in impaired tumor maintenance and represent a therapeutic strategy for neurofibroma therapy.
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Mehlman CT, Shepherd MA, Norris CS, McCourt JB. Diagnosis and treatment of osteopenic fractures in children. Curr Osteoporos Rep 2012; 10:317-21. [PMID: 23073639 DOI: 10.1007/s11914-012-0126-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Osteopenic fractures occur in children every day. At times the osteopenic nature of these fractures is painfully obvious, as in neurofibromatosis and osteogenesis imperfecta, while in many other situations overt osteopenia does not declare itself, such as in normal and obese children. Normal pediatric bone growth commonly involves periods of relative bone weakness. Childhood obesity creates a situation where bone is unable to fully adapt to the stresses placed upon it. Conditions like neurofibromatosis and osteogenesis imperfecta place pediatric bone at a distinct genetic disadvantage. This review will highlight recent research in these areas and provide radiographic examples of the treatment of osteopenic fractures in children.
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Affiliation(s)
- Charles T Mehlman
- Division of Pediatric Orthopaedic Surgery, Cincinnati Children's Hospital Medical Center, OH 45229-2017, USA.
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Bajaj A, Li QF, Zheng Q, Pumiglia K. Loss of NF1 expression in human endothelial cells promotes autonomous proliferation and altered vascular morphogenesis. PLoS One 2012; 7:e49222. [PMID: 23145129 PMCID: PMC3492274 DOI: 10.1371/journal.pone.0049222] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 10/04/2012] [Indexed: 12/30/2022] Open
Abstract
Neurofibromatosis is a well known familial tumor syndrome, however these patients also suffer from a number of vascular anomalies. The loss of NFl from the endothelium is embryonically lethal in mouse developmental models, however little is known regarding the molecular regulation by NF1 in endothelium. We investigated the consequences of losing NF1 expression on the function of endothelial cells using shRNA. The loss of NF1 was sufficient to elevate levels of active Ras under non-stimulated conditions. These elevations in Ras activity were associated with activation of downstream signaling including activation of ERK, AKT and mTOR. Cells knocked down in NF1 expression exhibited no cellular senescence. Rather, they demonstrated augmented proliferation and autonomous entry into the cell cycle. These proliferative changes were accompanied by enhanced expression of cyclin D, phosphorylation of p27KIP, and decreases in total p27KIP levels, even under growth factor free conditions. In addition, NF1-deficient cells failed to undergo normal branching morphogenesis in a co-culture assay, instead forming planar islands with few tubules and branches. We find the changes induced by the loss of NF1 could be mitigated by co-expression of the GAP-related domain of NF1 implicating Ras regulation in these effects. Using doxycycline-inducible shRNA, targeting NF1, we find that the morphogenic changes are reversible. Similarly, in fully differentiated and stable vascular-like structures, the silencing of NF1 results in the appearance of abnormal vascular structures. Finally, the proliferative changes and the abnormal vascular morphogenesis are normalized by low-dose rapamycin treatment. These data provide a detailed analysis of the molecular and functional consequences of NF1 loss in human endothelial cells. These insights may provide new approaches to therapeutically addressing vascular abnormalities in these patients while underscoring a critical role for normal Ras regulation in maintaining the health and function of the vasculature.
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Affiliation(s)
- Anshika Bajaj
- Center for Cell Biology and Cancer Research, Albany Medical College, Albany, New York, United States of America
| | - Qing-fen Li
- Center for Cell Biology and Cancer Research, Albany Medical College, Albany, New York, United States of America
| | - Qingxia Zheng
- Center for Cell Biology and Cancer Research, Albany Medical College, Albany, New York, United States of America
| | - Kevin Pumiglia
- Center for Cell Biology and Cancer Research, Albany Medical College, Albany, New York, United States of America
- * E-mail:
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Chong ZZ, Shang YC, Wang S, Maiese K. Shedding new light on neurodegenerative diseases through the mammalian target of rapamycin. Prog Neurobiol 2012; 99:128-48. [PMID: 22980037 PMCID: PMC3479314 DOI: 10.1016/j.pneurobio.2012.08.001] [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] [Received: 05/18/2012] [Revised: 08/01/2012] [Accepted: 08/07/2012] [Indexed: 12/13/2022]
Abstract
Neurodegenerative disorders affect a significant portion of the world's population leading to either disability or death for almost 30 million individuals worldwide. One novel therapeutic target that may offer promise for multiple disease entities that involve Alzheimer's disease, Parkinson's disease, epilepsy, trauma, stroke, and tumors of the nervous system is the mammalian target of rapamycin (mTOR). mTOR signaling is dependent upon the mTORC1 and mTORC2 complexes that are composed of mTOR and several regulatory proteins including the tuberous sclerosis complex (TSC1, hamartin/TSC2, tuberin). Through a number of integrated cell signaling pathways that involve those of mTORC1 and mTORC2 as well as more novel signaling tied to cytokines, Wnt, and forkhead, mTOR can foster stem cellular proliferation, tissue repair and longevity, and synaptic growth by modulating mechanisms that foster both apoptosis and autophagy. Yet, mTOR through its proliferative capacity may sometimes be detrimental to central nervous system recovery and even promote tumorigenesis. Further knowledge of mTOR and the critical pathways governed by this serine/threonine protein kinase can bring new light for neurodegeneration and other related diseases that currently require new and robust treatments.
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Affiliation(s)
- Zhao Zhong Chong
- Laboratory of Cellular and Molecular Signaling, New Jersey 07101
- New Jersey Health Sciences University Newark, New Jersey 07101
| | - Yan Chen Shang
- Laboratory of Cellular and Molecular Signaling, New Jersey 07101
- New Jersey Health Sciences University Newark, New Jersey 07101
| | - Shaohui Wang
- Laboratory of Cellular and Molecular Signaling, New Jersey 07101
- New Jersey Health Sciences University Newark, New Jersey 07101
| | - Kenneth Maiese
- Laboratory of Cellular and Molecular Signaling, New Jersey 07101
- Cancer Institute of New Jersey, New Jersey 07101
- New Jersey Health Sciences University Newark, New Jersey 07101
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Alanne MH, Siljamäki E, Peltonen S, Väänänen K, Windle JJ, Parada LF, Määttä JA, Peltonen J. Phenotypic characterization of transgenic mice harboring Nf1+/− or Nf1−/− osteoclasts in otherwise Nf1+/+ background. J Cell Biochem 2012; 113:2136-46. [DOI: 10.1002/jcb.24088] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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