1
|
Ajmeera D, Ajumeera R. Drug repurposing: A novel strategy to target cancer stem cells and therapeutic resistance. Genes Dis 2024; 11:148-175. [PMID: 37588226 PMCID: PMC10425757 DOI: 10.1016/j.gendis.2022.12.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 11/21/2022] [Accepted: 12/08/2022] [Indexed: 01/21/2023] Open
Abstract
Chemotherapy is an effortless and frequently used approach in cancer therapy. However, in most cases, it can only prolong life expectancy and does not guarantee a complete cure. Furthermore, chemotherapy is associated with severe adverse effects, one of the major complications of effective cancer therapy. In addition, newly published research outputs show that cancer stem cells are involved in cancer disease progression, drug resistance, metastasis, and recurrence and that they are functional in the trans-differentiation capacity of cancer stem cells to cancer cells in response to treatments. Novel strategies are therefore required for better management of cancer therapy. The prime approach would be to synthesize and develop novel drugs that need extensive resources, time, and endurance to be brought into therapeutic use. The subsequent approach would be to screen the anti-cancer activity of available non-cancerous drugs. This concept of repurposing non-cancer drugs as an alternative to current cancer therapy has become popular in recent years because using existing anticancer drugs has several adverse effects. Micronutrients have also been investigated for cancer therapy due to their significant anti-cancer effects with negligible or no side effects and availability in food sources. In this paper, we discuss an ideal hypothesis for screening available non-cancerous drugs with anticancer activity, with a focus on cancer stem cells and their clinical application for cancer treatment. Further, drug repurposing and the combination of micronutrients that can target both cancers and cancer stem cells may result in a better therapeutic approach leading to maximum tumor growth control.
Collapse
Affiliation(s)
- Divya Ajmeera
- Cell Biology Department, ICMR-National Institute of Nutrition (NIN), Hyderabad, Telangana 500007, India
| | - Rajanna Ajumeera
- Cell Biology Department, ICMR-National Institute of Nutrition (NIN), Hyderabad, Telangana 500007, India
| |
Collapse
|
2
|
Verduin M, Hoosemans L, Vanmechelen M, van Heumen M, Piepers JAF, Astuti G, Ackermans L, Schijns OEMG, Kampen KR, Tjan-Heijnen VCG, de Barbanson BA, Postma AA, Eekers DBP, Broen MPG, Beckervordersandforth J, Staňková K, de Smet F, Rich J, Hubert CG, Gimenez G, Chatterjee A, Hoeben A, Vooijs MA. Patient-derived glioblastoma organoids reflect tumor heterogeneity and treatment sensitivity. Neurooncol Adv 2023; 5:vdad152. [PMID: 38130902 PMCID: PMC10733660 DOI: 10.1093/noajnl/vdad152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023] Open
Abstract
Background Treatment resistance and tumor relapse are the primary causes of mortality in glioblastoma (GBM), with intratumoral heterogeneity playing a significant role. Patient-derived cancer organoids have emerged as a promising model capable of recapitulating tumor heterogeneity. Our objective was to develop patient-derived GBM organoids (PGO) to investigate treatment response and resistance. Methods GBM samples were used to generate PGOs and analyzed using whole-exome sequencing (WES) and single-cell karyotype sequencing. PGOs were subjected to temozolomide (TMZ) to assess viability. Bulk RNA sequencing was performed before and after TMZ. Results WES analysis on individual PGOs cultured for 3 time points (1-3 months) showed a high inter-organoid correlation and retention of genetic variants (range 92.3%-97.7%). Most variants were retained in the PGO compared to the tumor (range 58%-90%) and exhibited similar copy number variations. Single-cell karyotype sequencing demonstrated preservation of genetic heterogeneity. Single-cell multiplex immunofluorescence showed maintenance of cellular states. TMZ treatment of PGOs showed a differential response, which largely corresponded with MGMT promoter methylation. Differentially expressed genes before and after TMZ revealed an upregulation of the JNK kinase pathway. Notably, the combination treatment of a JNK kinase inhibitor and TMZ demonstrated a synergistic effect. Conclusions Overall, these findings demonstrate the robustness of PGOs in retaining the genetic and phenotypic heterogeneity in culture and the application of measuring clinically relevant drug responses. These data show that PGOs have the potential to be further developed into avatars for personalized adaptive treatment selection and actionable drug target discovery and as a platform to study GBM biology.
Collapse
Affiliation(s)
- Maikel Verduin
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Linde Hoosemans
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Maxime Vanmechelen
- Laboratory for Precision Cancer Medicine, Translational Cell and Tissue Research Unit, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
- LISCO—KU Leuven Institute for Single Cell Omics, KU Leuven, Leuven, Belgium
| | - Mike van Heumen
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Jolanda A F Piepers
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Galuh Astuti
- Department of Pathology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Linda Ackermans
- Department of Neurosurgery, School for Mental Health and Neuroscience (MHeNS), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Olaf E M G Schijns
- Department of Neurosurgery, School for Mental Health and Neuroscience (MHeNS), Maastricht University Medical Center, Maastricht, The Netherlands
- Academic Center for Epileptology, Maastricht University Medical Center and Kempenhaeghe, Maastricht—Heeze, The Netherlands
| | - Kim R Kampen
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre, Maastricht, The Netherlands
- Laboratory for Disease Mechanisms in Cancer, Department of Oncology, KU Leuven, Leuven, Belgium
| | - Vivianne C G Tjan-Heijnen
- Department of Medical Oncology, GROW School for Oncology and Reproduction, Maastricht University Medical Centre, Maastricht, The Netherlands
| | | | - Alida A Postma
- Department of Radiology and Nuclear Medicine, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Danielle B P Eekers
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Martijn P G Broen
- Department of Neurology, Maastricht University Medical Center, Maastricht, The Netherlands
| | | | - Katerina Staňková
- Institute for Health Systems Science, Delft University of Technology, Delft, The Netherlands
| | - Frederik de Smet
- Laboratory for Precision Cancer Medicine, Translational Cell and Tissue Research Unit, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
- LISCO—KU Leuven Institute for Single Cell Omics, KU Leuven, Leuven, Belgium
| | - Jeremy Rich
- University of Pittsburgh Medical Center Hillman Cancer Center, Pittsburgh, Pennsylvania, USA
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Christopher G Hubert
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Gregory Gimenez
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Aniruddha Chatterjee
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Ann Hoeben
- Department of Medical Oncology, GROW School for Oncology and Reproduction, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Marc A Vooijs
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre, Maastricht, The Netherlands
| |
Collapse
|
3
|
Talukdar S, Das SK, Emdad L, Fisher PB. Autophagy and senescence: Insights from normal and cancer stem cells. Adv Cancer Res 2021; 150:147-208. [PMID: 33858596 DOI: 10.1016/bs.acr.2021.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Autophagy is a fundamental cellular process, which allows cells to adapt to metabolic stress through the degradation and recycling of intracellular components to generate macromolecular precursors and produce energy. Autophagy is also critical in maintaining cellular/tissue homeostasis, as well preserving immunity and preventing human disease. Deregulation of autophagic processes is associated with cancer, neurodegeneration, muscle and heart disease, infectious diseases and aging. Research on a variety of stem cell types establish that autophagy plays critical roles in normal and cancer stem cell quiescence, activation, differentiation, and self-renewal. Considering its critical function in regulating the metabolic state of stem cells, autophagy plays a dual role in the regulation of normal and cancer stem cell senescence, and cellular responses to various therapeutic strategies. The relationships between autophagy, senescence, dormancy and apoptosis frequently focus on responses to various forms of stress. These are interrelated processes that profoundly affect normal and abnormal human physiology that require further elucidation in cancer stem cells. This review provides a current perspective on autophagy and senescence in both normal and cancer stem cells.
Collapse
Affiliation(s)
- Sarmistha Talukdar
- Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, VA, United States; VCU Institute of Molecular Medicine, Virginia Commonwealth University, School of Medicine, Richmond, VA, United States
| | - Swadesh K Das
- Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, VA, United States; VCU Institute of Molecular Medicine, Virginia Commonwealth University, School of Medicine, Richmond, VA, United States; VCU Massey Cancer Center, Virginia Commonwealth University, School of Medicine, Richmond, VA, United States
| | - Luni Emdad
- Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, VA, United States; VCU Institute of Molecular Medicine, Virginia Commonwealth University, School of Medicine, Richmond, VA, United States; VCU Massey Cancer Center, Virginia Commonwealth University, School of Medicine, Richmond, VA, United States
| | - Paul B Fisher
- Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, VA, United States; VCU Institute of Molecular Medicine, Virginia Commonwealth University, School of Medicine, Richmond, VA, United States; VCU Massey Cancer Center, Virginia Commonwealth University, School of Medicine, Richmond, VA, United States.
| |
Collapse
|
4
|
Wang B, Kohli J, Demaria M. Senescent Cells in Cancer Therapy: Friends or Foes? Trends Cancer 2020; 6:838-857. [PMID: 32482536 DOI: 10.1016/j.trecan.2020.05.004] [Citation(s) in RCA: 244] [Impact Index Per Article: 61.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 05/05/2020] [Accepted: 05/07/2020] [Indexed: 01/10/2023]
Abstract
Several cancer interventions induce DNA damage and promote senescence in cancer and nonmalignant cells. Senescent cells secrete a collection of proinflammatory factors collectively termed the senescence-associated secretory phenotype (SASP). SASP factors are able to potentiate various aspects of tumorigenesis, including proliferation, metastasis, and immunosuppression. Moreover, the accumulation and persistence of therapy-induced senescent cells can promote tissue dysfunction and the early onset of various age-related symptoms in treated cancer patients. Here, we review in detail the mechanisms by which cellular senescence contributes to cancer development and the side effects of cancer therapies. We also review how pharmacological interventions to eliminate senescent cells or inhibit SASP production can mitigate these negative effects and propose therapeutic strategies based on the age of the patient.
Collapse
Affiliation(s)
- Boshi Wang
- European Research Institute for the Biology of Ageing (ERIBA), University Medical Center Groningen, 9713AV Groningen, The Netherlands
| | - Jaskaren Kohli
- European Research Institute for the Biology of Ageing (ERIBA), University Medical Center Groningen, 9713AV Groningen, The Netherlands
| | - Marco Demaria
- European Research Institute for the Biology of Ageing (ERIBA), University Medical Center Groningen, 9713AV Groningen, The Netherlands.
| |
Collapse
|
5
|
Wang Y, Xia Y, Hu K, Zeng M, Zhi C, Lai M, Wu L, Liu S, Zeng S, Huang Z, Ma S, Yuan Z. MKK7 transcription positively or negatively regulated by SP1 and KLF5 depends on HDAC4 activity in glioma. Int J Cancer 2019; 145:2496-2508. [PMID: 30963560 DOI: 10.1002/ijc.32321] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 02/11/2019] [Accepted: 03/28/2019] [Indexed: 12/14/2022]
Abstract
JNK activity has been implicated in the malignant proliferation, invasion and drug-resistance of glioma cells (GCs), but the molecular mechanisms underlying JNK activation are currently unknown. Here, we reported that MKK7, not MKK4, directly activates JNK in GCs and exerts oncogenic effects on tumor formation. Notably, MKK7 expression in glioma tissues was closely correlated with the grade of the glioma and JNK/c-Jun activation. Mechanistically, MKK7 transcription critically depends on the complexes formed by HDAC4 and the transcriptional factors SP1 and Krüppel-like factor-5 (KLF5), wherein HDAC4 directly deacetylates both SP1 and KLF5 and synergistically upregulates MKK7 transcription through two SP1 sites located on its promoter. In contrast, the increases in acetylated-SP1 and acetylated-KLF5 after HDAC4 inhibition switched to transcriptionally suppress MKK7. Selective inhibition of HDAC4 by LMK235, siRNAs or blockage of SP1 and KLF5 by the ectopic dominant-negative SP1 greatly reduced the malignant capacity of GCs. Furthermore, suppression of both MKK7 expression and JNK/c-Jun activities was involved in the tumor-growth inhibitory effects induced by LMK235 in U87-xenograft mice. Interestingly, HDAC4 is highly expressed in glioma tissues, and the rate of HDAC4 nuclear import is closely correlated with glioma grade, as well as with MKK7 expression. Collectively, these findings demonstrated that highly expressed MKK7 contributes to JNK/c-Jun signaling-mediated glioma formation. MKK7 transcription, regulated by SP1 and KLF5, critically depends on HDAC4 activity, and inhibition of HDAC4 presents a potential strategy for suppressing the oncogenic roles of MKK7/JNK/c-Jun signaling in GCs.
Collapse
Affiliation(s)
- Yezhong Wang
- Department of Neurosurgery and Neurosurgical Disease Research Centre, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Institute of Neurosciences of Guangzhou Medical University, Guangzhou, China
| | - Yong Xia
- Department of Neurosurgery and Neurosurgical Disease Research Centre, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Institute of Neurosciences of Guangzhou Medical University, Guangzhou, China
| | - Kunhua Hu
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Guangdong Province Key Laboratory of Brain Function and Disease, Guangzhou, China
| | - Minling Zeng
- Department of Neurosurgery and Neurosurgical Disease Research Centre, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Institute of Neurosciences of Guangzhou Medical University, Guangzhou, China
| | - Cheng Zhi
- Department of Pathology, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Miaoling Lai
- Department of Pathology, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Liqiang Wu
- Department of Neurosurgery and Neurosurgical Disease Research Centre, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Institute of Neurosciences of Guangzhou Medical University, Guangzhou, China
| | - Sisi Liu
- Department of Neurosurgery and Neurosurgical Disease Research Centre, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Institute of Neurosciences of Guangzhou Medical University, Guangzhou, China
| | - Shulian Zeng
- Department of Neurosurgery and Neurosurgical Disease Research Centre, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Institute of Neurosciences of Guangzhou Medical University, Guangzhou, China
| | - Ziyan Huang
- Department of Neurosurgery and Neurosurgical Disease Research Centre, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Institute of Neurosciences of Guangzhou Medical University, Guangzhou, China
| | - Shanshan Ma
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Guangdong Province Key Laboratory of Brain Function and Disease, Guangzhou, China
| | - Zhongmin Yuan
- Department of Neurosurgery and Neurosurgical Disease Research Centre, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Institute of Neurosciences of Guangzhou Medical University, Guangzhou, China
- Guangdong Province Key Laboratory of Brain Function and Disease, Guangzhou, China
| |
Collapse
|
6
|
Huang Z, Xia Y, Hu K, Zeng S, Wu L, Liu S, Zhi C, Lai M, Chen D, Xie L, Yuan Z. Histone deacetylase 6 promotes growth of glioblastoma through the MKK7/JNK/c-Jun signaling pathway. J Neurochem 2019; 152:221-234. [PMID: 31390677 DOI: 10.1111/jnc.14849] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 07/30/2019] [Accepted: 07/31/2019] [Indexed: 12/20/2022]
Abstract
Histone deacetylase 6 (HDAC6) activity contributes to the malignant proliferation, invasion, and migration of glioma cells (GCs), but the molecular mechanisms underlying the processes remains elusive. Here, we reported that HDAC6 inhibition by Ricolinostat (ACY-1215) or CAY10603 led to a remarkable decrease in the phosphorylation of c-Jun N-terminal kinase (JNK) and c-Jun, which preceded its suppressive effects on glioma cell growth. Further investigation showed that these effects resulted from HDAC6 inhibitor-induced suppression of MAPK kinase 7 (MKK7), which was identified to be critical for JNK activation and exerts the oncogenic roles in GCs. Selectively silencing HDAC6 by siRNAs had the same responses, whereas transient transfections expressing HDAC6 promoted MKK7 expression. Interestingly, by performing Q-PCR, HDAC6 inhibition did not cause a down-regulation of MKK7 mRNA level, whereas the suppressive effects on MKK7 protein can be efficiently blocked by the proteasomal inhibitor MG132. As a further test, elevating MKK7-JNK activity was sufficient to rescue HDAC6 inhibitor-mediated-suppressive effects on c-Jun activation and the malignant features. The suppression of both MKK7 expression and JNK/c-Jun activities was involved in the tumor-growth inhibitory effects induced by CAY10603 in U87-xenograft mice. Collectively, our findings provide new insights into the molecular mechanism of glioma malignancy regarding HDAC6 in the selective regulation of MKK7 expression and JNK/c-Jun activity. MKK7 protein stability critically depends on HDAC6 activity, and inhibition of HDAC6 probably presents a potential strategy for suppressing the oncogenic roles of MKK7/JNK/c-Jun axis in GCs.
Collapse
Affiliation(s)
- Ziyan Huang
- Department of Neurosurgery and Neurosurgical Disease Research Centre, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Institute of Neurosciences of Guangzhou Medical University, Guangzhou, China
| | - Yong Xia
- Department of Neurosurgery and Neurosurgical Disease Research Centre, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Institute of Neurosciences of Guangzhou Medical University, Guangzhou, China
| | - Kunhua Hu
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Guangdong Province Key laboratory of Brain Function and Disease, Guangzhou, China
| | - Shulian Zeng
- Department of Neurosurgery and Neurosurgical Disease Research Centre, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Institute of Neurosciences of Guangzhou Medical University, Guangzhou, China
| | - Liqiang Wu
- Department of Neurosurgery and Neurosurgical Disease Research Centre, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Institute of Neurosciences of Guangzhou Medical University, Guangzhou, China
| | - Sisi Liu
- Department of Neurosurgery and Neurosurgical Disease Research Centre, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Institute of Neurosciences of Guangzhou Medical University, Guangzhou, China
| | - Cheng Zhi
- Department of Pathology, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Miaoling Lai
- Department of Pathology, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Danmin Chen
- Department of Neurosurgery and Neurosurgical Disease Research Centre, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Institute of Neurosciences of Guangzhou Medical University, Guangzhou, China
| | - Longchang Xie
- Institute of Neurosciences of Guangzhou Medical University, Guangzhou, China
| | - Zhongmin Yuan
- Department of Neurosurgery and Neurosurgical Disease Research Centre, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Institute of Neurosciences of Guangzhou Medical University, Guangzhou, China.,Guangdong Province Key laboratory of Brain Function and Disease, Guangzhou, China
| |
Collapse
|
7
|
Luo D, Xu X, Li J, Chen C, Chen W, Wang F, Xie Y, Li F. The PDK1/c‑Jun pathway activated by TGF‑β induces EMT and promotes proliferation and invasion in human glioblastoma. Int J Oncol 2018; 53:2067-2080. [PMID: 30106127 DOI: 10.3892/ijo.2018.4525] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 07/23/2018] [Indexed: 11/05/2022] Open
Abstract
Glioblastoma multiforme (GBM) is the most common primary malignant tumor affecting the human brain. Despite improvements in therapeutic technologies, patients with GBM have a poor clinical result and the molecular mechanisms responsible for the development of GBM have not yet been fully elucidated. 3-phosphoinositide dependent protein kinase 1 (PDK1) is upregulated in various tumors and promotes tumor invasion. In glioma, transforming growth factor-β (TGF‑β) promotes cell invasion; however, whether TGF‑β directly regulates PDK1 protein and promotes proliferation and invasion is not yet clear. In this study, PDK1 levels were measured in glioma tissues using tissue microarray (TMA) by immunohistochemistry (IHC) and RT‑qPCR. Kaplan-Meier analyses were used to calculate the survival rate of patients with glioma. In vitro, U251 and U87 glioma cell lines were used for functional analyses. Cell proliferation and invasion were analyzed using siRNA transfection, MTT assay, RT‑qPCR, western blot analysis, flow cytometry and invasion assay. In vivo, U251 glioma cell xenografts were established. The results revealed that PDK1 protein was significantly upregulated in glioma tissues compared with non-tumorous tissues. Furthermore, the higher PDK1 levels were associated with a large tumor size (>5.0 cm), a higher WHO grade and a shorter survival of patients with GBM. Univariate and multivariate analyses indicated that PDK1 was an independent prognostic factor. In vivo, PDK1 promoted glioma tumor xenograft growth. In vitro, functional analyses confirmed that TGF‑β upregulated PDK1 protein expression and PDK1 promoted cell migration and invasion, and functioned as an oncogene in GBM, by upregulating c‑Jun protein and inducing epithelial-mesenchymal transition (EMT). c‑Jun protein were overexpressed in glioma tissues and positively correlated with PDK1 levels. Moreover, our findings were further validated by the online Oncomine database. On the whole, the findings of this study indicate that in GBM, PDK1 functions as an oncogene, promoting proliferation and invasion.
Collapse
Affiliation(s)
- Dingyuan Luo
- Department of Vascular and Thyroid Surgery, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong 510120, P.R. China
| | - Xinke Xu
- Department of Neurosurgery, Guangzhou Women and Children's Medical Center, Guangzhou, Guangdong 510120, P.R. China
| | - Junliang Li
- Department of Neurosurgery, Guangzhou Women and Children's Medical Center, Guangzhou, Guangdong 510120, P.R. China
| | - Cheng Chen
- Department of Neurosurgery, Guangzhou Women and Children's Medical Center, Guangzhou, Guangdong 510120, P.R. China
| | - Wei Chen
- Department of Neurosurgery, Guangzhou Women and Children's Medical Center, Guangzhou, Guangdong 510120, P.R. China
| | - Fangyu Wang
- Department of Neurosurgery, Guangzhou Women and Children's Medical Center, Guangzhou, Guangdong 510120, P.R. China
| | - Yanping Xie
- Department of Neurosurgery, Guangzhou Women and Children's Medical Center, Guangzhou, Guangdong 510120, P.R. China
| | - Fangcheng Li
- Department of Neurosurgery, Guangzhou Women and Children's Medical Center, Guangzhou, Guangdong 510120, P.R. China
| |
Collapse
|
8
|
Rutin increases the cytotoxicity of temozolomide in glioblastoma via autophagy inhibition. J Neurooncol 2017; 132:393-400. [PMID: 28293765 DOI: 10.1007/s11060-017-2387-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 02/23/2017] [Indexed: 12/18/2022]
Abstract
The chemotherapeutic agent temozolomide (TMZ) is widely used in the treatment of glioblastoma multiforme (GBM). Rutin, a citrus flavonoid ecglycoside found in edible plants, has neuroprotective and anticancer activities. This study aimed to investigate the efficacy and the underlying mechanisms of rutin used in combination with TMZ in GBM. In vitro cell viability assay demonstrated that rutin alone had generally low cytotoxic effect, but it enhanced the efficacy of TMZ in a dose-dependent manner. Subcutaneous and orthotopic xenograft studies also showed that tumor volumes were significantly lower in mice receiving combined TMZ/Rutin treatment as compared to TMZ or rutin alone treatment. Moreover, immunoblotting analysis showed that TMZ activated JNK activity to induce protective response autophagy, which was blocked by rutin, resulting in decreased autophagy and increased apoptosis, suggesting that rutin enhances TMZ efficacy both in vitro and in vivo via inhibiting JNK-mediated autophagy in GBM. The combination rutin with TMZ may be a potentially useful therapeutic approach for GBM patient.
Collapse
|
9
|
Apoptosis induced by temozolomide and nimustine in glioblastoma cells is supported by JNK/c-Jun-mediated induction of the BH3-only protein BIM. Oncotarget 2016; 6:33755-68. [PMID: 26418950 PMCID: PMC4741800 DOI: 10.18632/oncotarget.5274] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 09/03/2015] [Indexed: 12/16/2022] Open
Abstract
The outcome of cancer therapy strongly depends on the complex network of cell signaling pathways, including transcription factor activation following drug exposure. Here we assessed whether and how the MAP kinase (MAPK) cascade and its downstream target, the transcription factor AP-1, influence the sensitivity of malignant glioma cells to the anticancer drugs temozolomide (TMZ) and nimustine (ACNU). Both drugs induce apoptosis in glioma cells at late times following treatment. Activation of the MAPK cascade precedes apoptosis, as shown by phosphorylation of Jun kinase (JNK) and c-Jun, a main component of AP-1. Pharmacological inhibition and siRNA mediated knockdown of JNK and c-Jun reduced the level of apoptosis in LN-229 glioma cells treated with TMZ or ACNU. Analyzing the underlying molecular mechanism, we identified the pro-apoptotic gene BIM as a critical target of AP-1, which is upregulated following TMZ and ACNU. Importantly, shRNA mediated downregulation of BIM in the malignant glioma cell lines LN-229 and U87MG led to an attenuated cleavage of caspase-9 and, consequently, reduced the level of apoptosis following TMZ and ACNU treatment. Overall, we identified JNK/c-Jun activation and BIM induction as a late pro-apoptotic response of glioma cells treated with alkylating anticancer drugs.
Collapse
|
10
|
Costa AM, Pinto F, Martinho O, Oliveira MJ, Jordan P, Reis RM. Silencing of the tumor suppressor gene WNK2 is associated with upregulation of MMP2 and JNK in gliomas. Oncotarget 2015; 6:1422-34. [PMID: 25596741 PMCID: PMC4359304 DOI: 10.18632/oncotarget.2805] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 11/25/2014] [Indexed: 11/25/2022] Open
Abstract
Matrix metalloproteinases (MMPs) are proteolytic enzymes that degrade extracellular matrix (ECM), thus assisting invasion. Upregulation of MMPs, frequently reported in gliomas, is associated with aggressive behavior. WNK2 is a tumor suppressor gene expressed in normal brain, and silenced by promoter methylation in gliomas. Patients without WNK2 exhibited poor prognosis, and its downregulation was associated with increased glioma cell invasion. Here we showed that MMP2 expression and activity are increased in glioma cell lines that do not express WNK2. Also, WNK2 inhibited JNK, a process associated with decreasing levels of MMP2. Thus, WNK2 promoter methylation and silencing in gliomas is associated with increased JNK activation and MMP2 expression and activity, thus explaining in part tumor cell invasion potential.
Collapse
Affiliation(s)
- Angela Margarida Costa
- ICVS-Life and Health Sciences Research Institute, School of Health Sciences, University of Minho, Campus Gualtar, Braga 4710-057, Portugal.,ICVS/3B's - PT -Government Associate Laboratory, Braga/Guimarães 4710-057, Portugal
| | - Filipe Pinto
- ICVS-Life and Health Sciences Research Institute, School of Health Sciences, University of Minho, Campus Gualtar, Braga 4710-057, Portugal.,ICVS/3B's - PT -Government Associate Laboratory, Braga/Guimarães 4710-057, Portugal
| | - Olga Martinho
- ICVS-Life and Health Sciences Research Institute, School of Health Sciences, University of Minho, Campus Gualtar, Braga 4710-057, Portugal.,ICVS/3B's - PT -Government Associate Laboratory, Braga/Guimarães 4710-057, Portugal
| | | | - Peter Jordan
- Department of Human Genetics, National Institute of Health Doutor Ricardo Jorge, Lisbon 1649-016, Portugal.,BioFig-Center of Biodiversity, Functional and Integrative Genomics, Lisbon 1649-016, Portugal
| | - Rui Manuel Reis
- ICVS-Life and Health Sciences Research Institute, School of Health Sciences, University of Minho, Campus Gualtar, Braga 4710-057, Portugal.,ICVS/3B's - PT -Government Associate Laboratory, Braga/Guimarães 4710-057, Portugal.,Molecular Oncology Research Center, Barretos Cancer Hospital, Barretos, SP 14784-400, Brazil
| |
Collapse
|
11
|
Ueno H, Tomiyama A, Yamaguchi H, Uekita T, Shirakihara T, Nakashima K, Otani N, Wada K, Sakai R, Arai H, Mori K. Augmentation of invadopodia formation in temozolomide-resistant or adopted glioma is regulated by c-Jun terminal kinase-paxillin axis. Biochem Biophys Res Commun 2015; 468:240-7. [PMID: 26518652 DOI: 10.1016/j.bbrc.2015.10.122] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 10/23/2015] [Indexed: 10/25/2022]
Abstract
Temozolomide (TMZ) is one of the few effective anticancer agents against gliomas. However, acquisition of TMZ resistance or adaptation by gliomas is currently a crucial problem, especially increased invasiveness which is critical for the determination of clinical prognosis. This study investigated the molecular regulatory mechanisms of TMZ resistance in gliomas involved in invasiveness, particularly invadopodia formation, a molecular complex formed at the invasive front to cause extracellular matrix degradation during cellular local invasion. The TMZ-resistant clone of the U343 MG human glioma cell line (U343-R cells) was established. U343-R cells demonstrated higher invadopodia formation compared with U343 cells without TMZ resistance (U343-Con cells). Immunoblot analysis of DNA damage-related mitogen-activated protein kinase signals found increased phosphorylation of c-Jun terminal kinase (JNK) and higher activation of its downstream signaling in U343-R cells compared with U343-Con cells. Treatment of U343-R cells with specific inhibitors of JNK or siRNA targeting JNK suppressed up-regulation of invadopodia formation. In addition, paxillin, one of the known JNK effectors which is phosphorylated and affects cell migration, was phosphorylated at serine 178 in JNK activity-dependent manner. Expression of paxillin with mutation of the serine 178 phosphorylation site in U343-R cells blocked invadopodia formation. The present findings suggest that increased formation of invadopodia in U343-R cells is mediated by hyperactivation of JNK-paxillin signaling, and both JNK and paxillin might become targets of novel therapies against TMZ-resistant gliomas.
Collapse
Affiliation(s)
- Hideaki Ueno
- Department of Neurosurgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan; Division of Metastasis and Invasion Signaling, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan; Department of Neurosurgery, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Arata Tomiyama
- Department of Neurosurgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan; Division of Metastasis and Invasion Signaling, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
| | - Hideki Yamaguchi
- Division of Metastasis and Invasion Signaling, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
| | - Takamasa Uekita
- Department of Applied Chemistry, National Defense Academy, 1-10-20 Hashirimizu, Yokosuka, Kanagawa 239-8686, Japan
| | - Takuya Shirakihara
- Division of Metastasis and Invasion Signaling, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
| | - Katsuhiko Nakashima
- Division of Metastasis and Invasion Signaling, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
| | - Naoki Otani
- Department of Neurosurgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Kojiro Wada
- Department of Neurosurgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Ryuichi Sakai
- Division of Metastasis and Invasion Signaling, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
| | - Hajime Arai
- Department of Neurosurgery, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Kentaro Mori
- Department of Neurosurgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| |
Collapse
|
12
|
Zanotto-Filho A, Braganhol E, Klafke K, Figueiró F, Terra SR, Paludo FJ, Morrone M, Bristot IJ, Battastini AM, Forcelini CM, Bishop AJR, Gelain DP, Moreira JCF. Autophagy inhibition improves the efficacy of curcumin/temozolomide combination therapy in glioblastomas. Cancer Lett 2015; 358:220-231. [DOI: 10.1016/j.canlet.2014.12.044] [Citation(s) in RCA: 132] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 12/18/2014] [Accepted: 12/19/2014] [Indexed: 12/14/2022]
|
13
|
Okada M, Sato A, Shibuya K, Watanabe E, Seino S, Suzuki S, Seino M, Narita Y, Shibui S, Kayama T, Kitanaka C. JNK contributes to temozolomide resistance of stem-like glioblastoma cells via regulation of MGMT expression. Int J Oncol 2013; 44:591-9. [PMID: 24316756 DOI: 10.3892/ijo.2013.2209] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Accepted: 10/18/2013] [Indexed: 11/05/2022] Open
Abstract
While elimination of the cancer stem cell population is increasingly recognized as a key to successful treatment of cancer, the high resistance of cancer stem cells to conventional chemoradiotherapy remains a therapeutic challenge. O6-methylguanine DNA methyltransferase (MGMT), which is frequently expressed in cancer stem cells of glioblastoma, has been implicated in their resistance to temozolomide, the first-line chemotherapeutic agent against newly diagnosed glioblastoma. However, much remains unknown about the molecular regulation that underlies MGMT expression and temozolomide resistance of glioblastoma cancer stem cells. Here, we identified JNK as a novel player in the control of MGMT expression and temozolomide resistance of glioblastoma cancer stem cells. We showed that inhibition of JNK, either pharmacologically or by RNA interference, in stem-like glioblastoma cells derived directly from glioblastoma tissues reduces their MGMT expression and temozolomide resistance. Importantly, sensitization of stem-like glioblastoma cells to temozolomide by JNK inhibition was dependent on MGMT expression, implying that JNK controls temozolomide resistance of stem-like glioblastoma cells through MGMT expression. Our findings suggest that concurrent use of JNK inhibitors with temozolomide may be a rational therapeutic approach to effectively target the cancer stem cell population in the treatment of glioblastoma.
Collapse
Affiliation(s)
- Masashi Okada
- Department of Molecular Cancer Science, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Atsushi Sato
- Department of Molecular Cancer Science, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Keita Shibuya
- Department of Molecular Cancer Science, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Eriko Watanabe
- Department of Molecular Cancer Science, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Shizuka Seino
- Department of Molecular Cancer Science, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Shuhei Suzuki
- Department of Molecular Cancer Science, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Manabu Seino
- Department of Molecular Cancer Science, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Yoshitaka Narita
- Department of Neurosurgery and Neuro-Oncology, National Cancer Center Hospital, Tokyo 104-0045, Japan
| | - Soichiro Shibui
- Department of Neurosurgery and Neuro-Oncology, National Cancer Center Hospital, Tokyo 104-0045, Japan
| | - Takamasa Kayama
- Department of Neurosurgery, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Chifumi Kitanaka
- Department of Molecular Cancer Science, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| |
Collapse
|
14
|
Gielen PR, Aftab Q, Ma N, Chen VC, Hong X, Lozinsky S, Naus CC, Sin WC. Connexin43 confers Temozolomide resistance in human glioma cells by modulating the mitochondrial apoptosis pathway. Neuropharmacology 2013; 75:539-48. [PMID: 23688923 DOI: 10.1016/j.neuropharm.2013.05.002] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 04/26/2013] [Accepted: 05/01/2013] [Indexed: 10/26/2022]
Abstract
Glioblastoma multiforme (GBM) is the most aggressive astrocytoma, and therapeutic options are generally limited to surgical resection, radiotherapy, and Temozolomide (TMZ) chemotherapy. TMZ is a DNA alkylating agent that causes DNA damage and induces cell death. Unfortunately, glioma cells often develop resistance to TMZ treatment, with DNA de-methylation of the MGMT promoter identified as the primary reason. However, the contributions from proteins that normally protect cells against cytotoxic stress in TMZ-induced apoptosis have not been extensively explored. Here, we showed that increasing the level of the gap junction protein, Cx43, in human LN18 and LN229 glioma cells enhances resistance to TMZ treatment while knockdown of Cx43 in these same cells sensitizes them to TMZ treatment. By expressing a channel-dead or a C-terminal truncation mutant of Cx43, we show that Cx43-mediated TMZ resistance involves both channel dependent and independent functions. Expression of Cx43 in LN229 cells decreases TMZ-induced apoptosis, as determined by Annexin V staining. Cx43-mediated chemoresistance appears to be acting via a mitochondrial apoptosis pathway as manifested by the reduction in Bax/Bcl-2 ratio and the release of cytochrome C. Our findings highlight additional mechanisms and proteins that contribute to TMZ resistance, and raise the possibility of increasing TMZ efficiency by targeting Cx43 protein. This article is part of the Special Issue Section entitled 'Current Pharmacology of Gap Junction Channels and Hemichannels'.
Collapse
Affiliation(s)
- Paul R Gielen
- Department of Cellular and Physiological Science, Life Science Institute, University of British Columbia, 2350 Health Science Mall, Vancouver, BC V6T 1Z3, Canada; Department of Tumor Immunology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, 6500 HB Nijmegen, Netherlands
| | - Qurratulain Aftab
- Department of Cellular and Physiological Science, Life Science Institute, University of British Columbia, 2350 Health Science Mall, Vancouver, BC V6T 1Z3, Canada
| | - Noreen Ma
- Department of Cellular and Physiological Science, Life Science Institute, University of British Columbia, 2350 Health Science Mall, Vancouver, BC V6T 1Z3, Canada
| | - Vincent C Chen
- Department of Cellular and Physiological Science, Life Science Institute, University of British Columbia, 2350 Health Science Mall, Vancouver, BC V6T 1Z3, Canada
| | - Xiaoting Hong
- Department of Cellular and Physiological Science, Life Science Institute, University of British Columbia, 2350 Health Science Mall, Vancouver, BC V6T 1Z3, Canada
| | - Shannon Lozinsky
- Department of Cellular and Physiological Science, Life Science Institute, University of British Columbia, 2350 Health Science Mall, Vancouver, BC V6T 1Z3, Canada
| | - Christian C Naus
- Department of Cellular and Physiological Science, Life Science Institute, University of British Columbia, 2350 Health Science Mall, Vancouver, BC V6T 1Z3, Canada
| | - Wun Chey Sin
- Department of Cellular and Physiological Science, Life Science Institute, University of British Columbia, 2350 Health Science Mall, Vancouver, BC V6T 1Z3, Canada.
| |
Collapse
|
15
|
Yeung YT, McDonald KL, Grewal T, Munoz L. Interleukins in glioblastoma pathophysiology: implications for therapy. Br J Pharmacol 2013; 168:591-606. [PMID: 23062197 PMCID: PMC3579281 DOI: 10.1111/bph.12008] [Citation(s) in RCA: 159] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 09/18/2012] [Accepted: 09/26/2012] [Indexed: 12/14/2022] Open
Abstract
Despite considerable amount of research, the poor prognosis of patients diagnosed with glioblastoma multiforme (GBM) critically needs new drug development to improve clinical outcomes. The development of an inflammatory microenvironment has long been considered important in the initiation and progression of glioblastoma; however, the success of developing therapeutic approaches to target inflammation for GBM therapy has yet been limited. Here, we summarize the accumulating evidence supporting a role for inflammation in the pathogenesis of glioblastoma, discuss anti-inflammatory targets that could be relevant for GBM treatment and provide a perspective on the challenges faced in the development of drugs that target GBM inflammation. In particular, we will review the function of IL-1β, IL-6 and IL-8 as well as the potential of kinase inhibitors targeting key players in inflammatory cell signalling cascades such as JAK, JNK and p38 MAPK.
Collapse
Affiliation(s)
- Y T Yeung
- Faculty of Pharmacy, University of Sydney, Sydney, NSW, Australia
| | | | | | | |
Collapse
|
16
|
The glutathione transferase inhibitor 6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio)hexanol (NBDHEX) increases temozolomide efficacy against malignant melanoma. Eur J Cancer 2011; 47:1219-30. [DOI: 10.1016/j.ejca.2010.12.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Revised: 12/01/2010] [Accepted: 12/14/2010] [Indexed: 11/23/2022]
|
17
|
Chen X, Wu J, Hua D, Shu K, Wang JZ, Li L, Lei T. The c-Jun N-terminal kinase inhibitor SP600125 is neuroprotective in amygdala kindled rats. Brain Res 2010; 1357:104-14. [PMID: 20692238 DOI: 10.1016/j.brainres.2010.07.082] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2010] [Revised: 07/21/2010] [Accepted: 07/22/2010] [Indexed: 11/25/2022]
Abstract
c-Jun N-terminal kinase (JNK) is implicated in cell death in neurodegenerative disorders and has been taken as a critical point between the physiological and pathological status. JNK specific inhibitor SP600125 has been found to have a protective effect against transient brain ischemia/reperfusion-induced neuronal death in rat hippocampal CA1 region. Former studies have shown the relation between JNK phosphorylation and neuronal damage in models of brain ischemia or in chemically or acute electrically kindled animal in which the stimulus-induced JNK phosphorylation was temporary or transient. In this study, the effect of repeated activation of JNK was examined in the amygdala kindled rats, under or without intraventrical infusion of SP600125, compared with the sham control. JNK phosphorylation was detected by Western blot and immunofluorescent staining in hippocampal extracts and in slices respectively. Nissl staining was performed to detect the neuronal defect. We found that the level of JNK phosphorylation (46KD) in the hippocampus increased in the amygdala kindled rats, whereas such JNK phosphorylation could be inhibited by SP600125. Expression of total JNK in the hippocampus remained unchanged in kindled rats compared with the sham control, and was not affected by SP600125. Neuronal defect was marked in the kindling group and in the vehicle DMSO group, and was alleviated under the administration of SP600125. These findings suggest that JNK phosphorylation is involved in the process of hippocampal sclerosis in the mesial temporal lobe epilepsy (TLE). JNK signaling pathway may be a new target to interfere with the development of hippocampal sclerosis in the temporal lobe epilepsy. The JNK inhibitor SP600125 can show a protective effect on hippocampal neurons in TLE by inhibiting JNK activation.
Collapse
Affiliation(s)
- Xu Chen
- Department of Neurosurgery, Tongji Hospital, Huazhong University of Science and Technology, Jiefang Ave 1095, 430030 Wuhan, China
| | | | | | | | | | | | | |
Collapse
|