1
|
Ando S, Tanaka K, Matsumoto M, Oyama Y, Tomabechi Y, Yamagata A, Shirouzu M, Nakagawa R, Okimoto N, Taiji M, Sato K, Ohama T. The luciferase-based in vivo protein-protein interaction assay revealed that CHK1 promotes PP2A and PME-1 interaction. J Biol Chem 2024; 300:107277. [PMID: 38588804 PMCID: PMC11098961 DOI: 10.1016/j.jbc.2024.107277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 03/12/2024] [Accepted: 04/02/2024] [Indexed: 04/10/2024] Open
Abstract
Protein phosphatase 2A (PP2A) is an essential serine/threonine protein phosphatase, and its dysfunction is involved in the onset of cancer and neurodegenerative disorders. PP2A functions as a trimeric holoenzyme whose composition is regulated by the methyl-esterification (methylation) of the PP2A catalytic subunit (PP2Ac). Protein phosphatase methylesterase-1 (PME-1) is the sole PP2Ac methylesterase, and the higher PME-1 expression is observed in various cancer and neurodegenerative diseases. Apart from serving as a methylesterase, PME-1 acts as a PP2A inhibitory protein, binding directly to PP2Ac and suppressing its activity. The intricate function of PME-1 hinders drug development by targeting the PME-1/PP2Ac axis. This study applied the NanoBiT system, a bioluminescence-based protein interaction assay, to elucidate the molecular mechanism that modulates unknown PME-1/PP2Ac protein-protein interaction (PPI). Compound screening identified that the CHK1 inhibitors inhibited PME-1/PP2Ac association without affecting PP2Ac methylation levels. CHK1 directly phosphorylates PP2Ac to promote PME-1 association. Phospho-mass spectrometry identified multiple phospho-sites on PP2Ac, including the Thr219, that affect PME-1 interaction. An anti-phospho-Thr219 PP2Ac antibody was generated and showed that CHK1 regulates the phosphorylation levels of this site in cells. On the contrary, in vitro phosphatase assay showed that CHK1 is the substrate of PP2A, and PME-1 hindered PP2A-mediated dephosphorylation of CHK1. Our data provides novel insights into the molecular mechanisms governing the PME-1/PP2Ac PPI and the triad relationship between PP2A, PME-1, and CHK1.
Collapse
Affiliation(s)
- Sana Ando
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Keiko Tanaka
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Maharu Matsumoto
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Yuki Oyama
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Yuri Tomabechi
- Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa, Japan
| | - Atsushi Yamagata
- Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa, Japan
| | - Mikako Shirouzu
- Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa, Japan
| | - Reiko Nakagawa
- Laboratory for Cell-Free Protein Synthesis, RIKEN Center for Biosystems Dynamics Research, Kobe, Hyogo, Japan
| | - Noriaki Okimoto
- Laboratory for Computational Molecular Design, RIKEN Center for Biosystems Dynamics Research (BDR), Osaka, Japan; Drug Discovery Molecular Simulation Platform Unit, RIKEN Center for Biosystems Dynamics Research (BDR), Osaka, Japan
| | - Makoto Taiji
- Laboratory for Computational Molecular Design, RIKEN Center for Biosystems Dynamics Research (BDR), Osaka, Japan; Drug Discovery Molecular Simulation Platform Unit, RIKEN Center for Biosystems Dynamics Research (BDR), Osaka, Japan
| | - Koichi Sato
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan; Research Institute for Cell Design Medical Science, Yamaguchi University, Yamaguchi, Japan
| | - Takashi Ohama
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan; Research Institute for Cell Design Medical Science, Yamaguchi University, Yamaguchi, Japan.
| |
Collapse
|
2
|
Ito M, Tanuma N, Kotani Y, Murai K, Kondo A, Sumiyoshi M, Shima H, Matsuda S, Watanabe T. Oncogenic K-Ras G12V cannot overcome proliferation failure caused by loss of Ppp6c in mouse embryonic fibroblasts. FEBS Open Bio 2024; 14:545-554. [PMID: 38318686 PMCID: PMC10988750 DOI: 10.1002/2211-5463.13775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 12/11/2023] [Accepted: 01/22/2024] [Indexed: 02/07/2024] Open
Abstract
Protein phosphatase 6 is a Ser/Thr protein phosphatase and its catalytic subunit is Ppp6c. Ppp6c is thought to be indispensable for proper growth of normal cells. On the other hand, loss of Ppp6c accelerates growth of oncogenic Ras-expressing cells. Although it has been studied in multiple contexts, the role(s) of Ppp6c in cell proliferation remains controversial. It is unclear how oncogenic K-Ras overcomes cell proliferation failure induced by Ppp6c deficiency; therefore, in this study, we attempted to shed light on how oncogenic K-Ras modulates tumor cell growth. Contrary to our expectations, loss of Ppp6c decreased proliferation, anchorage-independent growth in soft agar, and tumor formation of oncogenic Ras-expressing mouse embryonic fibroblasts (MEFs). These findings show that oncogenic K-RasG12V cannot overcome proliferation failure caused by loss of Ppp6c in MEFs.
Collapse
Affiliation(s)
- Mai Ito
- Department of Biological Science, Graduate School of Humanities and SciencesNara Women's UniversityJapan
| | - Nobuhiro Tanuma
- Division of Cancer ChemotherapyMiyagi Cancer Center Research InstituteNatoriJapan
| | - Yui Kotani
- Department of Biological Science, Graduate School of Humanities and SciencesNara Women's UniversityJapan
| | - Kokoro Murai
- Department of Biological Science, Graduate School of Humanities and SciencesNara Women's UniversityJapan
| | - Ayumi Kondo
- Department of Biological Science, Graduate School of Humanities and SciencesNara Women's UniversityJapan
| | - Mami Sumiyoshi
- Department of Cell Signaling, Institute of Biomedical ScienceKansai Medical UniversityHirakataJapan
| | - Hiroshi Shima
- Division of Cancer ChemotherapyMiyagi Cancer Center Research InstituteNatoriJapan
| | - Satoshi Matsuda
- Department of Cell Signaling, Institute of Biomedical ScienceKansai Medical UniversityHirakataJapan
| | - Toshio Watanabe
- Department of Biological Science, Graduate School of Humanities and SciencesNara Women's UniversityJapan
| |
Collapse
|
3
|
KITAMURA N, OHAMA T, SATO K. Protein phosphatase 6 promotes transforming growth factor-β signaling in mouse embryonic fibroblasts. J Vet Med Sci 2023; 85:1319-1323. [PMID: 37880139 PMCID: PMC10788163 DOI: 10.1292/jvms.23-0380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 10/15/2023] [Indexed: 10/27/2023] Open
Abstract
Transforming growth factor-beta (TGF-β) is a multifunctional cytokine that controls various cellular processes. Protein phosphatase 6 (PP6) is an evolutionarily conserved serine/threonine protein phosphatase with diverse functions in cell signaling. However, it has not been linked to TGF-β signaling. We found that TGF-β treatment increased PP6 protein levels via transcriptional and post-translational regulation. Loss of the Ppp6c gene suppressed TGF-β-induced canonical Smad3 phosphorylation and its transcriptional activity. PP6 knockout also inhibited non-canonical p38 mitogen-activated protein kinase (MAPK) pathway. Moreover, PP6 depletion suppressed cell migration induced by TGF-β. These findings uncovered the role of PP6 as a positive regulator for TGF-β signaling.
Collapse
Affiliation(s)
- Nao KITAMURA
- Laboratory of Veterinary Pharmacology, Yamaguchi University
Joint Graduate School of Veterinary Medicine, Yamaguchi, Japan
| | - Takashi OHAMA
- Laboratory of Veterinary Pharmacology, Yamaguchi University
Joint Graduate School of Veterinary Medicine, Yamaguchi, Japan
| | - Koichi SATO
- Laboratory of Veterinary Pharmacology, Yamaguchi University
Joint Graduate School of Veterinary Medicine, Yamaguchi, Japan
| |
Collapse
|
4
|
YAMAMOTO M, FUJIWARA N. Protein phosphatase 6 regulates trametinib sensitivity, a mitogen-activated protein kinase kinase (MEK) inhibitor, by regulating MEK1/2-ERK1/2 signaling in canine melanoma cells. J Vet Med Sci 2023; 85:977-984. [PMID: 37495516 PMCID: PMC10539826 DOI: 10.1292/jvms.23-0274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 07/17/2023] [Indexed: 07/28/2023] Open
Abstract
Melanoma is a highly aggressive and metastatic cancer occurring in both humans and dogs. Canine melanoma accounts for a significant proportion of neoplastic diseases in dogs, and despite standard treatments, overall survival rates remain low. Protein phosphatase 6 (PP6), an evolutionarily conserved serine/threonine protein phosphatase, regulates various biological processes. Additionally, the loss of PP6 function reportedly leads to the development of melanoma in humans. However, there are no reports regarding the role of PP6 in canine cancer cells. We, therefore, conducted a study investigating the role of PP6 in canine melanoma by using four canine melanoma cell lines: CMec1, CMM, KMeC and LMeC. PP6 knockdown increased phosphorylation levels of mitogen-activated protein kinase kinase 1/2 (MEK1/2) and extracellular signal-regulated kinase 1/2 (ERK1/2) but not Akt. Furthermore, PP6 knockdown decreased sensitivity to trametinib, a MEK inhibitor, but did not alter sensitivity to Akt inhibitor. These findings suggest that PP6 may function as a tumor suppressor in canine melanoma and modulate the response to trametinib treatment. Understanding the role of PP6 in canine melanoma could lead to the development of more effective treatment strategies for this aggressive disease.
Collapse
Affiliation(s)
- Miu YAMAMOTO
- Laboratory of Drug Discovery and Pharmacology, Faculty of Veterinary Medicine, Okayama University of Science, Ehime, Japan
| | - Nobuyuki FUJIWARA
- Laboratory of Drug Discovery and Pharmacology, Faculty of Veterinary Medicine, Okayama University of Science, Ehime, Japan
| |
Collapse
|
5
|
Chen XQ, Shen T, Fang SJ, Sun XM, Li GY, Li YF. Protein homeostasis in aging and cancer. Front Cell Dev Biol 2023; 11:1143532. [PMID: 36875752 PMCID: PMC9978402 DOI: 10.3389/fcell.2023.1143532] [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: 01/13/2023] [Accepted: 02/09/2023] [Indexed: 02/18/2023] Open
Abstract
Aging is a major risk factor for cancer development. As dysfunction in protein homeostasis, or proteostasis, is a universal hallmark of both the aging process and cancer, a comprehensive understanding of the proteostasis system and its roles in aging and cancer will shed new light on how we can improve health and quality of life for older individuals. In this review, we summarize the regulatory mechanisms of proteostasis and discuss the relationship between proteostasis and aging and age-related diseases, including cancer. Furthermore, we highlight the clinical application value of proteostasis maintenance in delaying the aging process and promoting long-term health.
Collapse
Affiliation(s)
- Xiao-Qiong Chen
- Colorectal Surgery, Third Affiliated Hospital of Kunming Medical University, Tumor Hospital of Yunnan Province, Kunming, China
| | - Tao Shen
- Colorectal Surgery, Third Affiliated Hospital of Kunming Medical University, Tumor Hospital of Yunnan Province, Kunming, China
| | - Shao-Jun Fang
- Colorectal Surgery, Third Affiliated Hospital of Kunming Medical University, Tumor Hospital of Yunnan Province, Kunming, China
| | - Xiao-Min Sun
- Colorectal Surgery, Third Affiliated Hospital of Kunming Medical University, Tumor Hospital of Yunnan Province, Kunming, China
| | - Guo-Yu Li
- Colorectal Surgery, Third Affiliated Hospital of Kunming Medical University, Tumor Hospital of Yunnan Province, Kunming, China
| | - Yun-Feng Li
- Colorectal Surgery, Third Affiliated Hospital of Kunming Medical University, Tumor Hospital of Yunnan Province, Kunming, China
| |
Collapse
|
6
|
Kokot T, Köhn M. Emerging insights into serine/threonine-specific phosphoprotein phosphatase function and selectivity. J Cell Sci 2022; 135:277104. [DOI: 10.1242/jcs.259618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
ABSTRACT
Protein phosphorylation on serine and threonine residues is a widely distributed post-translational modification on proteins that acts to regulate their function. Phosphoprotein phosphatases (PPPs) contribute significantly to a plethora of cellular functions through the accurate dephosphorylation of phosphorylated residues. Most PPPs accomplish their purpose through the formation of complex holoenzymes composed of a catalytic subunit with various regulatory subunits. PPP holoenzymes then bind and dephosphorylate substrates in a highly specific manner. Despite the high prevalence of PPPs and their important role for cellular function, their mechanisms of action in the cell are still not well understood. Nevertheless, substantial experimental advancements in (phospho-)proteomics, structural and computational biology have contributed significantly to a better understanding of PPP biology in recent years. This Review focuses on recent approaches and provides an overview of substantial new insights into the complex mechanism of PPP holoenzyme regulation and substrate selectivity.
Collapse
Affiliation(s)
- Thomas Kokot
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg 1 , Freiburg 79104 , Germany
- University of Freiburg, 2 Faculty of Biology , Freiburg 79104 , Germany
| | - Maja Köhn
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg 1 , Freiburg 79104 , Germany
- University of Freiburg, 2 Faculty of Biology , Freiburg 79104 , Germany
| |
Collapse
|
7
|
Fukui K, Nomura M, Kishimoto K, Tanuma N, Kurosawa K, Kanazawa K, Kato H, Sato T, Miura S, Miura K, Sato I, Tsuji H, Yamashita Y, Tamai K, Watanabe T, Yasuda J, Tanaka T, Satoh K, Furukawa T, Jingu K, Shima H. PP6 deficiency in mice with KRAS mutation and Trp53 loss promotes early death by PDAC with cachexia-like features. Cancer Sci 2022; 113:1613-1624. [PMID: 35247012 PMCID: PMC9128171 DOI: 10.1111/cas.15315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 02/15/2022] [Accepted: 02/22/2022] [Indexed: 11/30/2022] Open
Abstract
To examine effects of PP6 gene (Ppp6c) deficiency on pancreatic tumor development, we developed pancreas-specific, tamoxifen-inducible Cre-mediated KP (KRAS(G12D) plus Trp53-deficient) mice (cKP mice) and crossed them with Ppp6cflox / flox mice. cKP mice with the homozygous Ppp6c deletion developed pancreatic tumors, became emaciated and required euthanasia within 150 days of mutation induction, phenotypes that were not seen in heterozygous or wild-type (WT) mice. At 30 days, a comparative analysis of genes commonly altered in homozygous versus WT Ppp6c cKP mice revealed enhanced activation of Erk and NFκB pathways in homozygotes. By 80 days, the number and size of tumors and number of precancerous lesions had significantly increased in the pancreas of Ppp6c homozygous relative to heterozygous or WT cKP mice. Ppp6c-/- tumors were pathologically diagnosed as pancreatic ductal adenocarcinoma (PDAC) undergoing the epithelial-mesenchymal transition (EMT), and cancer cells had invaded surrounding tissues in three out of six cases. Transcriptome and metabolome analyses indicated an enhanced cancer-specific glycolytic metabolism in Ppp6c-deficient cKP mice and the increased expression of inflammatory cytokines. Individual Ppp6c-/- cKP mice showed weight loss, decreased skeletal muscle and adipose tissue, and increased circulating tumor necrosis factor (TNF)-α and IL-6 levels, suggestive of systemic inflammation. Overall, Ppp6c deficiency in the presence of K-ras mutations and Trp53 gene deficiency promoted pancreatic tumorigenesis with generalized cachexia and early death. This study provided the first evidence that Ppp6c suppresses mouse pancreatic carcinogenesis and supports the use of Ppp6c-deficient cKP mice as a model for developing treatments for cachexia associated with pancreatic cancer.
Collapse
Affiliation(s)
- Katsuya Fukui
- Division of Cancer ChemotherapyMiyagi Cancer Center Research InstituteNatoriJapan
- Division of Cancer Molecular BiologyTohoku University Graduate School of MedicineSendaiJapan
- Department of Radiation OncologyTohoku University Graduate School of MedicineSendaiJapan
| | - Miyuki Nomura
- Division of Cancer ChemotherapyMiyagi Cancer Center Research InstituteNatoriJapan
| | - Kazuhiro Kishimoto
- Division of Cancer ChemotherapyMiyagi Cancer Center Research InstituteNatoriJapan
- Division of Cancer Molecular BiologyTohoku University Graduate School of MedicineSendaiJapan
- Department of Head and Neck SurgeryKanazawa Medical UniversityKanazawaJapan
| | - Nobuhiro Tanuma
- Division of Cancer ChemotherapyMiyagi Cancer Center Research InstituteNatoriJapan
- Division of Cancer Molecular BiologyTohoku University Graduate School of MedicineSendaiJapan
| | - Koreyuki Kurosawa
- Division of Cancer ChemotherapyMiyagi Cancer Center Research InstituteNatoriJapan
- Division of Cancer Molecular BiologyTohoku University Graduate School of MedicineSendaiJapan
- Department of Plastic and Reconstructive SurgeryTohoku University Graduate School of MedicineSendaiJapan
| | - Kosuke Kanazawa
- Division of Cancer ChemotherapyMiyagi Cancer Center Research InstituteNatoriJapan
- Division of Cancer Molecular BiologyTohoku University Graduate School of MedicineSendaiJapan
- Division of SurgeryMiyagi Cancer CenterNatoriJapan
| | - Hiroyuki Kato
- Division of Cancer ChemotherapyMiyagi Cancer Center Research InstituteNatoriJapan
| | - Tomoki Sato
- Laboratory of Nutritional BiochemistryGraduate School of Nutritional and Environmental SciencesUniversity of ShizuokaShizuokaJapan
| | - Shinji Miura
- Laboratory of Nutritional BiochemistryGraduate School of Nutritional and Environmental SciencesUniversity of ShizuokaShizuokaJapan
| | - Koh Miura
- Division of Cancer ChemotherapyMiyagi Cancer Center Research InstituteNatoriJapan
- Division of SurgeryMiyagi Cancer CenterNatoriJapan
| | - Ikuro Sato
- Division of PathologyMiyagi Cancer CenterNatoriJapan
| | - Hiroyuki Tsuji
- Department of Head and Neck SurgeryKanazawa Medical UniversityKanazawaJapan
| | - Yoji Yamashita
- Division of Cancer ChemotherapyMiyagi Cancer Center Research InstituteNatoriJapan
| | - Keiichi Tamai
- Division of Cancer Stem CellMiyagi Cancer Center Research InstituteNatoriJapan
| | - Toshio Watanabe
- Department of Biological ScienceGraduate School of Humanities and SciencesNara Women’s UniversityNaraJapan
| | - Jun Yasuda
- Division of Cancer Molecular BiologyTohoku University Graduate School of MedicineSendaiJapan
- Division of Molecular Cellular OncologyMiyagi Cancer Center Research InstituteNatoriJapan
| | - Takuji Tanaka
- Research Center of Diagnostic PathologyGifu Municipal HospitalGifuJapan
| | - Kennichi Satoh
- Division of GastroenterologyTohoku Medical Pharmaceutical UniversitySendaiJapan
| | - Toru Furukawa
- Department of Investigative PathologyTohoku University Graduate School of MedicineSendaiJapan
| | - Keiichi Jingu
- Department of Radiation OncologyTohoku University Graduate School of MedicineSendaiJapan
| | - Hiroshi Shima
- Division of Cancer ChemotherapyMiyagi Cancer Center Research InstituteNatoriJapan
- Division of Cancer Molecular BiologyTohoku University Graduate School of MedicineSendaiJapan
| |
Collapse
|
8
|
Kohyanagi N, Kitamura N, Tanaka K, Mizuno T, Fujiwara N, Ohama T, Sato K. The protein level of the tumor-promoting factor SET is regulated by cell density. J Biochem 2022; 171:295-303. [PMID: 35076073 DOI: 10.1093/jb/mvab125] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 11/15/2021] [Indexed: 11/14/2022] Open
Abstract
SET/I2PP2A is a multifunctional protein that acts as an intrinsic inhibitor of the tumor suppressor protein phosphatase 2A and as a histone chaperone. Increased SET levels have been observed in various cancers; however, the underlying molecular mechanisms remain unclear. In this study, we found that SET protein accumulates with the increasing density of cultured cells. This phenomenon was observed not only in cancer cell lines but also in non-cancer cell lines. The mRNA levels of SET were not affected by the cell density. Proteasome inhibition decreased SET levels, whereas autophagy inhibition led to SET accumulation, indicating the involvement of autophagy. The mRNA and protein expression of SETBP1, which stabilizes the SET protein, increased with cell density. The decrease in SET level due to the loss of SETBP1 was more pronounced in wild-type cells than that in autophagy-deficient cells. These results have revealed a mechanism underlying the regulation of SET level, wherein increased cell density induces SETBP1 expression and protects SET from autophagy.
Collapse
Affiliation(s)
- Naoki Kohyanagi
- Laboratory of Veterinary Pharmacology and Laboratory of Molecular Diagnostics
| | - Nao Kitamura
- Laboratory of Veterinary Pharmacology and Laboratory of Molecular Diagnostics
| | - Keiko Tanaka
- Laboratory of Veterinary Pharmacology and Laboratory of Molecular Diagnostics
| | - Takuya Mizuno
- Laboratory of Molecular Diagnostics and Therapeutics, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, 753-8515, Japan
| | - Nobuyuki Fujiwara
- Laboratory of Drug Discovery and Pharmacology, Faculty of Veterinary Medicine, Okayama University of Science, 794-8555 Ehime, Japan
| | - Takashi Ohama
- Laboratory of Veterinary Pharmacology and Laboratory of Molecular Diagnostics
| | - Koichi Sato
- Laboratory of Veterinary Pharmacology and Laboratory of Molecular Diagnostics
| |
Collapse
|
9
|
Wang J, Liu G, Li X, Huangfu M, Liu Y, Li X, Yu D, Zhou L, Chen X. Curcumol simultaneously induces both apoptosis and autophagy in human nasopharyngeal carcinoma cells. Phytother Res 2021; 35:7004-7017. [PMID: 34750896 DOI: 10.1002/ptr.7321] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 10/02/2021] [Accepted: 10/18/2021] [Indexed: 01/14/2023]
Abstract
Autophagy is usually considered as a protective mechanism against cell death, and in the meantime, leads to cell injury even apoptosis. Apoptosis and autophagy are very closely connected and may cooperate, coexist, or antagonize each other on progressive occurrence of cell death triggered by natural compounds. Therefore, the interplay between the two modes of death is essential for the overall fate of cancer cells. Our previous study revealed that curcumol induced apoptosis in nasopharyngeal carcinoma (NPC) cells. Recently, curcumol was found to induce autophagy in cancer cells. However, whether curcumol can induce NPC cells autophagy and the effects of autophagy on apoptosis remain elusive. In this study, we found that curcumol induced autophagy through AMPK/mTOR pathway in CNE-2 cells. Moreover, inhibiting autophagy by autophagy inhibitor 3-methyladenine (3-MA) or apoptosis inhibitor z-VAD-fmk significantly increased proliferation while attenuated apoptosis and autophagy compared with the curcumol 212 μM group. In contrast, combining curcumol with autophagy agonist rapamycin and apoptosis inducer MG132 synergized the apoptotic and autophagic effect of curcumol. Taken together, our study demonstrates that curcumol promotes autophagy in NPC via AMPK/mTOR pathway, induces autophagy enhances the activity of curcumol in NPC cells; the combination of autophagy inducer and curcumol can be a new therapeutic strategy for NPC.
Collapse
Affiliation(s)
- Juan Wang
- Department of Pharmacy, Guilin Medical University, Guilin, China.,Guangxi Key Laboratory of Molecular Medicine in Liver Injury and Repair, the Affiliated Hospital of Guilin Medical University, Guilin, China.,Guangxi Health Commission Key Laboratory of Basic Research in Sphingolipid Metabolism Related Diseases, the Affiliated Hospital of Guilin Medical University, Guilin, China.,Faculty of Basic Medicine, Guilin Medical University, Guilin, China
| | - Guoxiang Liu
- Department of Pharmacy, Guilin Medical University, Guilin, China
| | - Xiaojuan Li
- Department of Pharmacy, Guilin Medical University, Guilin, China
| | - Mengjie Huangfu
- Department of Pharmacy, Guilin Medical University, Guilin, China
| | - Yisa Liu
- Department of Pharmacy, Guilin Medical University, Guilin, China
| | - Xumei Li
- Department of Pharmacy, Guilin Medical University, Guilin, China
| | - Dan Yu
- Department of Pharmacy, Guilin Medical University, Guilin, China
| | - Luwei Zhou
- Department of Pharmacy, Guilin Medical University, Guilin, China
| | - Xu Chen
- Department of Pharmacy, Guilin Medical University, Guilin, China
| |
Collapse
|
10
|
Kitamura N, Fujiwara N, Hayakawa K, Ohama T, Sato K. Protein phosphatase 6 promotes neurite outgrowth by promoting mTORC2 activity in N2a cells. J Biochem 2021; 170:131-138. [PMID: 34314486 DOI: 10.1093/jb/mvab028] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 03/08/2021] [Indexed: 11/14/2022] Open
Abstract
Understanding the molecular mechanism of neuronal differentiation is important to overcome the incurable diseases caused by nervous system damage. Neurite outgrowth is prerequisite for neuronal differentiation and regeneration, and cAMP response element-binding protein (CREB) is one of the major transcriptional factors positively regulating this process. Neuronal differentiation stimuli activate mammalian target of rapamycin (mTOR) complex 2 (mTORC2)/Akt signaling to phosphorylate CREB, however, the precise molecular mechanism of this event has not been fully understood. In this manuscript, we show that neuronal differentiation stimuli increased a protein level of protein phosphatase 6 (PP6), a member of type 2A Ser/Thr protein phosphatases. PP6 knockdown suppressed mTORC2/Akt/CREB signaling and results in failure of neurite outgrowth. SIN1 is a unique component of mTORC2 that enhances mTORC2 activity toward Akt when it is in dephosphorylated form. We found PP6 knockdown increased SIN1 phosphorylation. These data suggest that PP6 may positively regulate neurite outgrowth by dephosphorylating SIN1 to activate mTORC2/Akt/CREB signaling.
Collapse
Affiliation(s)
- Nao Kitamura
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | | | - Koji Hayakawa
- Department of Toxicology, Faculty of Veterinary Medicine, Okayama University of Science, 1-3 Ikoinooka, Imabari, 794-8555 Ehime, Japan
| | - Takashi Ohama
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Koichi Sato
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| |
Collapse
|
11
|
Kishimoto K, Kanazawa K, Nomura M, Tanaka T, Shigemoto-Kuroda T, Fukui K, Miura K, Kurosawa K, Kawai M, Kato H, Terasaki K, Sakamoto Y, Yamashita Y, Sato I, Tanuma N, Tamai K, Kitabayashi I, Matsuura K, Watanabe T, Yasuda J, Tsuji H, Shima H. Ppp6c deficiency accelerates K-ras G12D -induced tongue carcinogenesis. Cancer Med 2021; 10:4451-4464. [PMID: 34145991 PMCID: PMC8267137 DOI: 10.1002/cam4.3962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/09/2021] [Accepted: 04/19/2021] [Indexed: 12/18/2022] Open
Abstract
Background Effective treatments for cancer harboring mutant RAS are lacking. In Drosophila, it was reported that PP6 suppresses tumorigenicity of mutant RAS. However, the information how PP6 regulates oncogenic RAS in mammals is limited. Methods We examined the effects of PP6 gene (Ppp6c) deficiency on tongue tumor development in K (K‐rasG12D)‐ and KP (K‐rasG12D + Trp53‐deficient)‐inducible mice. Results Mice of K and KP genotypes developed squamous cell carcinoma in situ in the tongue approximately 2 weeks after the induction of Ppp6c deficiency and was euthanized due to 20% loss of body weight. Transcriptome analysis revealed significantly different gene expressions between tissues of Ppp6c‐deficient tongues and those of Ppp6c wild type, while Trp53 deficiency had a relatively smaller effect. We then analyzed genes commonly altered by Ppp6c deficiency, with or without Trp53 deficiency, and identified a group concentrated in KEGG database pathways defined as ‘Pathways in Cancer’ and ‘Cytokine‐cytokine receptor interaction’. We then evaluated signals downstream of oncogenic RAS and those regulated by PP6 substrates and found that in the presence of K‐rasG12D, Ppp6c deletion enhanced the activation of the ERK‐ELK1‐FOS, AKT‐4EBP1, and AKT‐FOXO‐CyclinD1 axes. Ppp6c deletion combined with K‐rasG12D also enhanced DNA double‐strand break (DSB) accumulation and activated NFκB signaling, upregulating IL‐1β, COX2, and TNF.
Collapse
Affiliation(s)
- Kazuhiro Kishimoto
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Cancer Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan.,Department of Head and Neck Surgery, Kanazawa Medical University, Kanazawa, Japan.,Department of Head and Neck Surgery, Miyagi Cancer Center, Miyagi, Japan
| | - Kosuke Kanazawa
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Cancer Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan.,Division of Surgery, Miyagi Cancer Center, Miyagi, Japan
| | - Miyuki Nomura
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Takuji Tanaka
- Research Center of Diagnostic Pathology, Gifu Municipal Hospital, Gifu, Japan
| | | | - Katsuya Fukui
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Cancer Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan
| | - Koh Miura
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Surgery, Miyagi Cancer Center, Miyagi, Japan
| | - Koreyuki Kurosawa
- Department of Plastic and Reconstructive Surgery, Tohoku University School of Medicine, Miyagi, Japan
| | - Masaaki Kawai
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Surgery, Miyagi Cancer Center, Miyagi, Japan
| | - Hiroyuki Kato
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Keiko Terasaki
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Yoshimi Sakamoto
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Yoji Yamashita
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Ikuro Sato
- Division of Pathology, Miyagi Cancer Center, Miyagi, Japan
| | - Nobuhiro Tanuma
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Cancer Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan
| | - Keiichi Tamai
- Division of Cancer Stem Cell, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Issay Kitabayashi
- Division of Hematological Malignancy, National Cancer Center Research Institute, Tokyo, Japan
| | - Kazuto Matsuura
- Department of Head and Neck Surgery, National Cancer Center Hospital East, Chiba, Japan
| | - Toshio Watanabe
- Department of Biological Science, Graduate School of Humanities and Sciences, Nara Women's University, Nara, Japan
| | - Jun Yasuda
- Division of Molecular and Cellular Oncology, Miyagi Cancer Center Research Institute, Miyagi, Japan
| | - Hiroyuki Tsuji
- Department of Head and Neck Surgery, Kanazawa Medical University, Kanazawa, Japan
| | - Hiroshi Shima
- Division of Cancer Chemotherapy, Miyagi Cancer Center Research Institute, Miyagi, Japan.,Division of Cancer Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan
| |
Collapse
|
12
|
Fujiwara N, Shibutani S, Ohama T, Sato K. Protein phosphatase 6 dissociates the Beclin 1/Vps34 complex and inhibits autophagy. Biochem Biophys Res Commun 2021; 552:191-195. [PMID: 33751937 DOI: 10.1016/j.bbrc.2021.02.136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 02/26/2021] [Indexed: 10/21/2022]
Abstract
Autophagy is an evolutionarily conserved intracellular degradation system and is regulated by various signaling pathways including the Beclin 1/Vacuolar protein sorting 34 (Vps34) complex. Protein phosphatase 6 (PP6) is an essential serine/threonine phosphatase that regulates various biological processes. Recently, we found that PP6 protein is degraded by p62-dependent selective autophagy. In this study, we show that PP6 conversely inhibits autophagy. PP6 associate with the C-terminal region of Beclin 1, which is close to the binding region of Vps34. The protein levels of PP6 affect Beclin 1/Vps34 complex formation and phosphatase activity of PP6 is not involved in this. We also show that chemically induced PP6/Beclin 1 association leads to Vps34 dissociation from Beclin 1. Overall, our data reveal a novel regulatory mechanism for autophagy by PP6.
Collapse
Affiliation(s)
- Nobuyuki Fujiwara
- Laboratory of Veterinary Pharmacology, 753-8515, Yamaguchi, Japan; Laboratory of Drug Discovery and Pharmacology, Faculty of Veterinary Medicine, Okayama University of Science, 794-8555, Ehime, Japan
| | - Shusaku Shibutani
- Laboratory of Veterinary Hygiene, Yamaguchi University, 753-8515, Yamaguchi, Japan
| | - Takashi Ohama
- Laboratory of Veterinary Pharmacology, 753-8515, Yamaguchi, Japan.
| | - Koichi Sato
- Laboratory of Veterinary Pharmacology, 753-8515, Yamaguchi, Japan
| |
Collapse
|
13
|
Lu C, Wu B, Liao Z, Xue M, Zou Z, Feng J, Sheng J. DUSP1 overexpression attenuates renal tubular mitochondrial dysfunction by restoring Parkin-mediated mitophagy in diabetic nephropathy. Biochem Biophys Res Commun 2021; 559:141-147. [PMID: 33940385 DOI: 10.1016/j.bbrc.2021.04.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 04/08/2021] [Indexed: 11/17/2022]
Abstract
Diabetic nephropathy (DN) is the primary cause of end-stage renal disease, and renal tubular cell dysfunction contributes to the pathogenesis of many kidney diseases. Our previous study demonstrated that dual-specificity protein phosphatase 1 (DUSP1) reduced hyperglycemia-mediated mitochondrial damage; however, its role in hyperglycemia-driven dysfunction of tubular cells is still not fully understood. In this study, we found that DUSP1 is reduced in human proximal tubular epithelial (HK-2) cells under high-glucose conditions. DUSP1 overexpression in HK-2 cells partially restored autophagic flux, improved mitochondrial function, and reduced reactive oxygen species generation and cell apoptosis under high-glucose conditions. Surprisingly, overexpressing DUSP1 abolished the decrease in mitochondrial parkin expression caused by high-glucose stimulation. In addition, knockdown of parkin in HK-2 cells reversed the effects of DUSP1 overexpression on mitophagy and apoptosis under high-glucose conditions. Overall, these data indicate that DUSP1 plays a defensive role in the pathogenesis of DN by restoring parkin-mediated mitophagy, suggesting that it may be considered a prospective therapeutic strategy for the amelioration of DN.
Collapse
Affiliation(s)
- Chang Lu
- Department of Nephrology, Xuhui District Central Hospital of Shanghai, Shanghai, 200003, China
| | - Bo Wu
- Department of Cardiology, Yangpu Hospital, Tongji University School of Medicine, Shanghai, China
| | - Zhuojun Liao
- Department of Nephrology, Xuhui District Central Hospital of Shanghai, Shanghai, 200003, China
| | - Ming Xue
- Department of Nephrology, Xuhui District Central Hospital of Shanghai, Shanghai, 200003, China
| | - Zhouping Zou
- Department of Nephrology, Xuhui District Central Hospital of Shanghai, Shanghai, 200003, China
| | - Jianxun Feng
- Department of Nephrology, Xuhui District Central Hospital of Shanghai, Shanghai, 200003, China.
| | - Junqin Sheng
- Department of Nephrology, Xuhui District Central Hospital of Shanghai, Shanghai, 200003, China.
| |
Collapse
|
14
|
Fujiwara N, Shibutani S, Sakai Y, Watanabe T, Kitabayashi I, Oshima H, Oshima M, Hoshida H, Akada R, Usui T, Ohama T, Sato K. Autophagy regulates levels of tumor suppressor enzyme protein phosphatase 6. Cancer Sci 2020; 111:4371-4380. [PMID: 32969571 PMCID: PMC7734157 DOI: 10.1111/cas.14662] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 09/12/2020] [Accepted: 09/16/2020] [Indexed: 12/20/2022] Open
Abstract
Protein phosphatase 6 (PP6) is an essential serine/threonine protein phosphatase that acts as an important tumor suppressor. However, increased protein levels of PP6 have been observed in some cancer types, and they correlate with poor prognosis in glioblastoma. This raises a question about how PP6 protein levels are regulated in normal and transformed cells. In this study, we show that PP6 protein levels increase in response to pharmacologic and genetic inhibition of autophagy. PP6 associates with autophagic adaptor protein p62/SQSTM1 and is degraded in a p62-dependent manner. Accordingly, protein levels of PP6 and p62 fluctuate in concert under different physiological and pathophysiological conditions. Our data reveal that PP6 is regulated by p62-dependent autophagy and suggest that accumulation of PP6 protein in tumor tissues is caused at least partially by deficiency in autophagy.
Collapse
Affiliation(s)
- Nobuyuki Fujiwara
- Laboratory of Veterinary Pharmacology, Yamaguchi University, Yamaguchi, Japan.,Laboratory of Drug Discovery and Pharmacology, Faculty of Veterinary Medicine, Okayama University of Science, Ehime, Japan
| | - Shusaku Shibutani
- Laboratory of Veterinary Hygiene, Yamaguchi University, Yamaguchi, Japan
| | - Yusuke Sakai
- Laboratory of Veterinary Pathology, Yamaguchi University, Yamaguchi, Japan
| | - Toshio Watanabe
- Department of Biological Science, Graduate School of Humanities and Sciences, Nara Women's University, Nara, Japan
| | - Issay Kitabayashi
- Division of Hematological Malignancy, National Cancer Center Research Institute, Tokyo, Japan
| | - Hiroko Oshima
- Division of Genetics, Cancer Research Institute, Kanazawa University, Kanazawa, Japan
| | - Masanobu Oshima
- Division of Genetics, Cancer Research Institute, Kanazawa University, Kanazawa, Japan
| | - Hisashi Hoshida
- Department of Applied Chemistry, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan
| | - Rinji Akada
- Department of Applied Chemistry, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan
| | - Tatsuya Usui
- Laboratory of Veterinary Pharmacology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Takashi Ohama
- Laboratory of Veterinary Pharmacology, Yamaguchi University, Yamaguchi, Japan
| | - Koichi Sato
- Laboratory of Veterinary Pharmacology, Yamaguchi University, Yamaguchi, Japan
| |
Collapse
|