1
|
Alderman C, Anderson R, Zhang L, Hughes CJ, Li X, Ebmeier C, Wagley ME, Ahn NG, Ford HL, Zhao R. Biochemical characterization of the Eya and PP2A-B55α interaction. J Biol Chem 2024; 300:107408. [PMID: 38796066 DOI: 10.1016/j.jbc.2024.107408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 04/22/2024] [Accepted: 05/09/2024] [Indexed: 05/28/2024] Open
Abstract
The eyes absent (Eya) proteins were first identified as co-activators of the six homeobox family of transcription factors and are critical in embryonic development. These proteins are also re-expressed in cancers after development is complete, where they drive tumor progression. We have previously shown that the Eya3 N-terminal domain (NTD) contains Ser/Thr phosphatase activity through an interaction with the protein phosphatase 2A (PP2A)-B55α holoenzyme and that this interaction increases the half-life of Myc through pT58 dephosphorylation. Here, we showed that Eya3 directly interacted with the NTD of Myc, recruiting PP2A-B55α to Myc. We also showed that Eya3 increased the Ser/Thr phosphatase activity of PP2A-B55α but not PP2A-B56α. Furthermore, we demonstrated that the NTD (∼250 amino acids) of Eya3 was completely disordered, and it used a 38-residue segment to interact with B55α. In addition, knockdown and phosphoproteomic analyses demonstrated that Eya3 and B55α affected highly similar phosphosite motifs with a preference for Ser/Thr followed by Pro, consistent with Eya3's apparent Ser/Thr phosphatase activity being mediated through its interaction with PP2A-B55α. Intriguingly, mutating this Pro to other amino acids in a Myc peptide dramatically increased dephosphorylation by PP2A. Not surprisingly, MycP59A, a naturally occurring mutation hotspot in several cancers, enhanced Eya3-PP2A-B55α-mediated dephosphorylation of pT58 on Myc, leading to increased Myc stability and cell proliferation, underscoring the critical role of this phosphosite in regulating Myc stability.
Collapse
Affiliation(s)
- Christopher Alderman
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA; Medical Scientist Training Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA; Molecular Biology Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Ryan Anderson
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Lingdi Zhang
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Connor J Hughes
- Medical Scientist Training Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA; Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Xueni Li
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Chris Ebmeier
- Department of Biochemistry, University of Colorado-Boulder, Boulder, Colorado, USA
| | - Marisa E Wagley
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Natalie G Ahn
- Department of Biochemistry, University of Colorado-Boulder, Boulder, Colorado, USA
| | - Heide L Ford
- Molecular Biology Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA; Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Rui Zhao
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA; Molecular Biology Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.
| |
Collapse
|
2
|
Luk IS, Bridgwater CM, Yu A, Boila LD, Yáñez-Bartolomé M, Lampano AE, Hulahan TS, Boukhali M, Kathiresan M, Macarulla T, Kenerson HL, Yamamoto N, Sokolov D, Engstrom IA, Sullivan LB, Lampe PD, Cooper JA, Yeung RS, Tian TV, Haas W, Saha SK, Kugel S. SRC inhibition enables formation of a growth suppressive MAGI1-PP2A complex in isocitrate dehydrogenase-mutant cholangiocarcinoma. Sci Transl Med 2024; 16:eadj7685. [PMID: 38748774 PMCID: PMC11218711 DOI: 10.1126/scitranslmed.adj7685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 04/25/2024] [Indexed: 07/04/2024]
Abstract
Intrahepatic cholangiocarcinoma (ICC) is an aggressive bile duct malignancy that frequently exhibits isocitrate dehydrogenase (IDH1/IDH2) mutations. Mutant IDH (IDHm) ICC is dependent on SRC kinase for growth and survival and is hypersensitive to inhibition by dasatinib, but the molecular mechanism underlying this sensitivity is unclear. We found that dasatinib reduced p70 S6 kinase (S6K) and ribosomal protein S6 (S6), leading to substantial reductions in cell size and de novo protein synthesis. Using an unbiased phosphoproteomic screen, we identified membrane-associated guanylate kinase, WW, and PDZ domain containing 1 (MAGI1) as an SRC substrate in IDHm ICC. Biochemical and functional assays further showed that SRC inhibits a latent tumor-suppressing function of the MAGI1-protein phosphatase 2A (PP2A) complex to activate S6K/S6 signaling in IDHm ICC. Inhibiting SRC led to activation and increased access of PP2A to dephosphorylate S6K, resulting in cell death. Evidence from patient tissue and cell line models revealed that both intrinsic and extrinsic resistance to dasatinib is due to increased phospho-S6 (pS6). To block pS6, we paired dasatinib with the S6K/AKT inhibitor M2698, which led to a marked reduction in pS6 in IDHm ICC cell lines and patient-derived organoids in vitro and substantial growth inhibition in ICC patient-derived xenografts in vivo. Together, these results elucidated the mechanism of action of dasatinib in IDHm ICC, revealed a signaling complex regulating S6K phosphorylation independent of mTOR, suggested markers for dasatinib sensitivity, and described a combination therapy for IDHm ICC that may be actionable in the clinic.
Collapse
Affiliation(s)
- Iris S. Luk
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | | | - Angela Yu
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Liberalis D. Boila
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Mariana Yáñez-Bartolomé
- Preclinical and Translational Research Program, Vall d’Hebron Institute of Oncology (VHIO), 08035 Barcelona, Spain
| | - Aaron E. Lampano
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Taylor S. Hulahan
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Myriam Boukhali
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA 02114, USA
| | - Meena Kathiresan
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA 02114, USA
| | - Teresa Macarulla
- Preclinical and Translational Research Program, Vall d’Hebron Institute of Oncology (VHIO), 08035 Barcelona, Spain
- Gastrointestinal and Endocrine Tumor Unit, Hospital Universitari Vall d’Hebron, Vall d’Hebron Barcelona Hospital Campus, 08035 Barcelona, Spain
| | - Heidi L. Kenerson
- Department of Surgery, University of Washington, Seattle, WA 98195, USA
| | - Naomi Yamamoto
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
- Medical Scientist Training Program, University of Washington, Seattle, WA 98195, USA
| | - David Sokolov
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Ian A. Engstrom
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Lucas B. Sullivan
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Paul D. Lampe
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Jonathan A. Cooper
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Raymond S. Yeung
- Department of Surgery, University of Washington, Seattle, WA 98195, USA
| | - Tian V. Tian
- Preclinical and Translational Research Program, Vall d’Hebron Institute of Oncology (VHIO), 08035 Barcelona, Spain
| | - Wilhelm Haas
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA 02114, USA
| | - Supriya K. Saha
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Sita Kugel
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| |
Collapse
|
3
|
Hughes CJ, Alderman C, Wolin AR, Fields KM, Zhao R, Ford HL. All eyes on Eya: A unique transcriptional co-activator and phosphatase in cancer. Biochim Biophys Acta Rev Cancer 2024; 1879:189098. [PMID: 38555001 PMCID: PMC11111358 DOI: 10.1016/j.bbcan.2024.189098] [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: 12/15/2023] [Revised: 03/26/2024] [Accepted: 03/27/2024] [Indexed: 04/02/2024]
Abstract
The Eya family of proteins (consisting of Eyas1-4 in mammals) play vital roles in embryogenesis by regulating processes such as proliferation, migration/invasion, cellular survival and pluripotency/plasticity of epithelial and mesenchymal states. Eya proteins carry out such diverse functions through a unique combination of transcriptional co-factor, Tyr phosphatase, and PP2A/B55α-mediated Ser/Thr phosphatase activities. Since their initial discovery, re-expression of Eyas has been observed in numerous tumor types, where they are known to promote tumor progression through a combination of their transcriptional and enzymatic activities. Eya proteins thus reinstate developmental processes during malignancy and represent a compelling class of therapeutic targets for inhibiting tumor progression.
Collapse
Affiliation(s)
- Connor J Hughes
- Medical Scientist Training Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States of America; Department of Pharmacology, University of Colorado Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045, United States of America
| | - Christopher Alderman
- Medical Scientist Training Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States of America; Molecular Biology Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States of America; Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States of America
| | - Arthur R Wolin
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045, United States of America; Molecular Biology Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States of America
| | - Kaiah M Fields
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045, United States of America; Molecular Biology Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States of America
| | - Rui Zhao
- Medical Scientist Training Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States of America; Molecular Biology Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States of America; Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States of America.
| | - Heide L Ford
- Medical Scientist Training Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States of America; Department of Pharmacology, University of Colorado Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045, United States of America; Molecular Biology Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States of America.
| |
Collapse
|
4
|
Wu CG, Balakrishnan VK, Merrill RA, Parihar PS, Konovolov K, Chen YC, Xu Z, Wei H, Sundaresan R, Cui Q, Wadzinski BE, Swingle MR, Musiyenko A, Chung WK, Honkanen RE, Suzuki A, Huang X, Strack S, Xing Y. B56δ long-disordered arms form a dynamic PP2A regulation interface coupled with global allostery and Jordan's syndrome mutations. Proc Natl Acad Sci U S A 2024; 121:e2310727120. [PMID: 38150499 PMCID: PMC10769853 DOI: 10.1073/pnas.2310727120] [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: 07/01/2023] [Accepted: 11/27/2023] [Indexed: 12/29/2023] Open
Abstract
Intrinsically disordered regions (IDR) and short linear motifs (SLiMs) play pivotal roles in the intricate signaling networks governed by phosphatases and kinases. B56δ (encoded by PPP2R5D) is a regulatory subunit of protein phosphatase 2A (PP2A) with long IDRs that harbor a substrate-mimicking SLiM and multiple phosphorylation sites. De novo missense mutations in PPP2R5D cause intellectual disabilities (ID), macrocephaly, Parkinsonism, and a broad range of neurological symptoms. Our single-particle cryo-EM structures of the PP2A-B56δ holoenzyme reveal that the long, disordered arms at the B56δ termini fold against each other and the holoenzyme core. This architecture suppresses both the phosphatase active site and the substrate-binding protein groove, thereby stabilizing the enzyme in a closed latent form with dual autoinhibition. The resulting interface spans over 190 Å and harbors unfavorable contacts, activation phosphorylation sites, and nearly all residues with ID-associated mutations. Our studies suggest that this dynamic interface is coupled to an allosteric network responsive to phosphorylation and altered globally by mutations. Furthermore, we found that ID mutations increase the holoenzyme activity and perturb the phosphorylation rates, and the severe variants significantly increase the mitotic duration and error rates compared to the normal variant.
Collapse
Affiliation(s)
- Cheng-Guo Wu
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin at Madison, School of Medicine and Public Health, Madison, WI53705
- Biophysics Program, University of Wisconsin at Madison, Madison, WI53706
| | - Vijaya K. Balakrishnan
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin at Madison, School of Medicine and Public Health, Madison, WI53705
| | - Ronald A. Merrill
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA52242
| | - Pankaj S. Parihar
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin at Madison, School of Medicine and Public Health, Madison, WI53705
| | - Kirill Konovolov
- Chemistry Department, University of Wisconsin at Madison, Madison, WI53706
| | - Yu-Chia Chen
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin at Madison, School of Medicine and Public Health, Madison, WI53705
- Molecular and Cellular Pharmacology Program, University of Wisconsin at Madison, Madison, WI53706
| | - Zhen Xu
- Protein and Crystallography Facility, University of Iowa, Iowa City, IA52242
| | - Hui Wei
- The Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY10027
| | - Ramya Sundaresan
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin at Madison, School of Medicine and Public Health, Madison, WI53705
| | - Qiang Cui
- Department of Chemistry, Boston University, Boston, MA02215
| | | | - Mark R. Swingle
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL36688
| | - Alla Musiyenko
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL36688
| | - Wendy K. Chung
- Department of Pediatrics, Boston Children’s Hospital, Harvard Medical School, Boston, MA02215
| | - Richard E. Honkanen
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL36688
| | - Aussie Suzuki
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin at Madison, School of Medicine and Public Health, Madison, WI53705
- Biophysics Program, University of Wisconsin at Madison, Madison, WI53706
- Molecular and Cellular Pharmacology Program, University of Wisconsin at Madison, Madison, WI53706
| | - Xuhui Huang
- Biophysics Program, University of Wisconsin at Madison, Madison, WI53706
- Chemistry Department, University of Wisconsin at Madison, Madison, WI53706
| | - Stefan Strack
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA52242
| | - Yongna Xing
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin at Madison, School of Medicine and Public Health, Madison, WI53705
- Biophysics Program, University of Wisconsin at Madison, Madison, WI53706
| |
Collapse
|
5
|
Breccia M. Atypical CML: diagnosis and treatment. HEMATOLOGY. AMERICAN SOCIETY OF HEMATOLOGY. EDUCATION PROGRAM 2023; 2023:476-482. [PMID: 38066919 PMCID: PMC10727105 DOI: 10.1182/hematology.2023000448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Atypical chronic myeloid leukemia (aCML) is included in the group of myelodysplastic/myeloproliferative neoplasms by the International Consensus Classification and has been renamed as MDS/MPN with neutrophilia by the fifth edition of World Health Organization classification. It is always characterized by morphologic identification of granulocytic dysplasia with >10% circulating immature myeloid cells, 2 distinguished features that differentiate this disease among the others. Somatic mutations may help to diagnose but are not specifically pathognomonic of the disease, with the most detected including ASXL1, SETBP1, NRAS, KRAS, SRSF2, and TET2 and with low-frequency CBL, CSF3R, JAK2, and ETNK1. The genomic landscape of aCML has been recently unravelling, revealing that SETBP1 and ETNK1 are usually not ancestral but secondary events associated with disease progression. Unfortunately, until now, no consensus on risk stratification and treatment has been developed: Mayo Clinic prognostic score identified as adverse events age >67 years, hemoglobin level <10 g/dL, and TET2 mutations. Although some possible genetic markers have been identified, allogeneic transplant remains the only curative strategy.
Collapse
MESH Headings
- Humans
- Aged
- Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative/diagnosis
- Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative/genetics
- Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative/therapy
- Myelodysplastic-Myeloproliferative Diseases/diagnosis
- Mutation
- Prognosis
- Disease Progression
Collapse
Affiliation(s)
- Massimo Breccia
- Department of Translational and Precision Medicine, Sapienza University, Rome, Italy
| |
Collapse
|
6
|
Doha ZO, Sears RC. Unraveling MYC's Role in Orchestrating Tumor Intrinsic and Tumor Microenvironment Interactions Driving Tumorigenesis and Drug Resistance. PATHOPHYSIOLOGY 2023; 30:400-419. [PMID: 37755397 PMCID: PMC10537413 DOI: 10.3390/pathophysiology30030031] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Revised: 09/04/2023] [Accepted: 09/08/2023] [Indexed: 09/28/2023] Open
Abstract
The transcription factor MYC plays a pivotal role in regulating various cellular processes and has been implicated in tumorigenesis across multiple cancer types. MYC has emerged as a master regulator governing tumor intrinsic and tumor microenvironment interactions, supporting tumor progression and driving drug resistance. This review paper aims to provide an overview and discussion of the intricate mechanisms through which MYC influences tumorigenesis and therapeutic resistance in cancer. We delve into the signaling pathways and molecular networks orchestrated by MYC in the context of tumor intrinsic characteristics, such as proliferation, replication stress and DNA repair. Furthermore, we explore the impact of MYC on the tumor microenvironment, including immune evasion, angiogenesis and cancer-associated fibroblast remodeling. Understanding MYC's multifaceted role in driving drug resistance and tumor progression is crucial for developing targeted therapies and combination treatments that may effectively combat this devastating disease. Through an analysis of the current literature, this review's goal is to shed light on the complexities of MYC-driven oncogenesis and its potential as a promising therapeutic target.
Collapse
Affiliation(s)
- Zinab O. Doha
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, OR 97239, USA;
- Department of Medical Laboratories Technology, Taibah University, Al-Madinah 42353, Saudi Arabia
| | - Rosalie C. Sears
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, OR 97239, USA;
- Brenden-Colson Center for Pancreatic Care, Oregon Health & Science University, Portland, OR 97201, USA
- Knight Cancer Institute, Oregon Health & Science University, Portland, OR 97201, USA
| |
Collapse
|
7
|
Domènech Omella J, Cortesi EE, Verbinnen I, Remmerie M, Wu H, Cubero FJ, Roskams T, Janssens V. A Novel Mouse Model of Combined Hepatocellular-Cholangiocarcinoma Induced by Diethylnitrosamine and Loss of Ppp2r5d. Cancers (Basel) 2023; 15:4193. [PMID: 37627221 PMCID: PMC10453342 DOI: 10.3390/cancers15164193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 08/11/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023] Open
Abstract
Primary liver cancer (PLC) can be classified in hepatocellular (HCC), cholangiocarcinoma (CCA), and combined hepatocellular-cholangiocarcinoma (cHCC-CCA). The molecular mechanisms involved in PLC development and phenotype decision are still not well understood. Complete deletion of Ppp2r5d, encoding the B56δ subunit of Protein Phosphatase 2A (PP2A), results in spontaneous HCC development in mice via a c-MYC-dependent mechanism. In the present study, we aimed to examine the role of Ppp2r5d in an independent mouse model of diethylnitrosamine (DEN)-induced hepatocarcinogenesis. Ppp2r5d deletion (heterozygous and homozygous) accelerated HCC development, corroborating its tumor-suppressive function in liver and suggesting Ppp2r5d may be haploinsufficient. Ppp2r5d-deficient HCCs stained positively for c-MYC, consistent with increased AKT activation in pre-malignant and tumor tissues of Ppp2r5d-deficient mice. We also found increased YAP activation in Ppp2r5d-deficient tumors. Remarkably, in older mice, Ppp2r5d deletion resulted in cHCC-CCA development in this model, with the CCA component showing increased expression of progenitor markers (SOX9 and EpCAM). Finally, we observed an upregulation of Ppp2r5d in tumors from wildtype and heterozygous mice, revealing a tumor-specific control mechanism of Ppp2r5d expression, and suggestive of the involvement of Ppp2r5d in a negative feedback regulation restricting tumor growth. Our study highlights the tumor-suppressive role of mouse PP2A-B56δ in both HCC and cHCC-CCA, which may have important implications for human PLC development and targeted treatment.
Collapse
Affiliation(s)
- Judit Domènech Omella
- Laboratory of Protein Phosphorylation & Proteomics, Department of Cellular & Molecular Medicine, University of Leuven (KU Leuven), 3000 Leuven, Belgium; (J.D.O.); (I.V.); (M.R.)
| | - Emanuela E. Cortesi
- Translational Cell & Tissue Research, University of Leuven (KU Leuven), 3000 Leuven, Belgium; (E.E.C.); (T.R.)
| | - Iris Verbinnen
- Laboratory of Protein Phosphorylation & Proteomics, Department of Cellular & Molecular Medicine, University of Leuven (KU Leuven), 3000 Leuven, Belgium; (J.D.O.); (I.V.); (M.R.)
| | - Michiel Remmerie
- Laboratory of Protein Phosphorylation & Proteomics, Department of Cellular & Molecular Medicine, University of Leuven (KU Leuven), 3000 Leuven, Belgium; (J.D.O.); (I.V.); (M.R.)
| | - Hanghang Wu
- Department of Immunology, Ophthalmology & ENT, Complutense University School of Medicine, 28040 Madrid, Spain; (H.W.); (F.J.C.)
| | - Francisco J. Cubero
- Department of Immunology, Ophthalmology & ENT, Complutense University School of Medicine, 28040 Madrid, Spain; (H.W.); (F.J.C.)
- Health Research Institute Gregorio Marañón (IiSGM), 28007 Madrid, Spain
- Centre for Biomedical Research, Network on Liver and Digestive Diseases (CIBEREHD), 28029 Madrid, Spain
| | - Tania Roskams
- Translational Cell & Tissue Research, University of Leuven (KU Leuven), 3000 Leuven, Belgium; (E.E.C.); (T.R.)
- Department of Pathology, University Hospitals Leuven (UZ Leuven), 3000 Leuven, Belgium
| | - Veerle Janssens
- Laboratory of Protein Phosphorylation & Proteomics, Department of Cellular & Molecular Medicine, University of Leuven (KU Leuven), 3000 Leuven, Belgium; (J.D.O.); (I.V.); (M.R.)
- KU Leuven Cancer Institute (LKI), 3000 Leuven, Belgium
| |
Collapse
|
8
|
Wu CG, Balakrishnan VK, Parihar PS, Konovolov K, Chen YC, Merrill RA, Wei H, Carragher B, Sundaresan R, Cui Q, Wadzinski BE, Swingle MR, Musiyenko A, Honkanen R, Chung WK, Suzuki A, Strack S, Huang X, Xing Y. Extended regulation interface coupled to the allosteric network and disease mutations in the PP2A-B56δ holoenzyme. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.09.530109. [PMID: 37066309 PMCID: PMC10103954 DOI: 10.1101/2023.03.09.530109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
An increasing number of mutations associated with devastating human diseases are diagnosed by whole-genome/exon sequencing. Recurrent de novo missense mutations have been discovered in B56δ (encoded by PPP2R5D), a regulatory subunit of protein phosphatase 2A (PP2A), that cause intellectual disabilities (ID), macrocephaly, Parkinsonism, and a broad range of neurological symptoms. Single-particle cryo-EM structures show that the PP2A-B56δ holoenzyme possesses closed latent and open active forms. In the closed form, the long, disordered arms of B56δ termini fold against each other and the holoenzyme core, establishing dual autoinhibition of the phosphatase active site and the substrate-binding protein groove. The resulting interface spans over 190 Å and harbors unfavorable contacts, activation phosphorylation sites, and nearly all residues with ID-associated mutations. Our studies suggest that this dynamic interface is close to an allosteric network responsive to activation phosphorylation and altered globally by mutations. Furthermore, we found that ID mutations perturb the activation phosphorylation rates, and the severe variants significantly increase the mitotic duration and error rates compared to the wild variant.
Collapse
Affiliation(s)
- Cheng-Guo Wu
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin at Madison, School of Medicine and Public Health, Madison, Wisconsin 53705, USA
- Biophysics program, University of Wisconsin at Madison, Wisconsin 53706, USA
| | - Vijaya K. Balakrishnan
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin at Madison, School of Medicine and Public Health, Madison, Wisconsin 53705, USA
| | - Pankaj S. Parihar
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin at Madison, School of Medicine and Public Health, Madison, Wisconsin 53705, USA
| | - Kirill Konovolov
- Chemistry Department, University of Wisconsin at Madison, Wisconsin 53706, USA
| | - Yu-Chia Chen
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin at Madison, School of Medicine and Public Health, Madison, Wisconsin 53705, USA
- Molecular and Cellular Pharmacology program, University of Wisconsin at Madison, Wisconsin 53706, USA
| | - Ronald A Merrill
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA 52242, USA
| | - Hui Wei
- New York Structural biology Center, New York, NY 10027, USA
| | | | - Ramya Sundaresan
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin at Madison, School of Medicine and Public Health, Madison, Wisconsin 53705, USA
| | - Qiang Cui
- Department of Chemistry, Metcalf Center for Science & Engineering, Boston University, Boston, MA 02215, USA
| | - Brian E. Wadzinski
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Mark R. Swingle
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Alla Musiyenko
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Richard Honkanen
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Wendy K. Chung
- Departments of Pediatrics and Medicine, Columbia University, New York, NY 10032, USA
| | - Aussie Suzuki
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin at Madison, School of Medicine and Public Health, Madison, Wisconsin 53705, USA
- Biophysics program, University of Wisconsin at Madison, Wisconsin 53706, USA
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA 52242, USA
| | - Stefan Strack
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA 52242, USA
| | - Xuhui Huang
- Biophysics program, University of Wisconsin at Madison, Wisconsin 53706, USA
- Chemistry Department, University of Wisconsin at Madison, Wisconsin 53706, USA
| | - Yongna Xing
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin at Madison, School of Medicine and Public Health, Madison, Wisconsin 53705, USA
- Biophysics program, University of Wisconsin at Madison, Wisconsin 53706, USA
| |
Collapse
|
9
|
Wu J, Fan S, Feinberg D, Wang X, Jabbar S, Kang Y. Inhibition of Sphingosine Kinase 2 Results in PARK2-Mediated Mitophagy and Induces Apoptosis in Multiple Myeloma. Curr Oncol 2023; 30:3047-3063. [PMID: 36975444 PMCID: PMC10047154 DOI: 10.3390/curroncol30030231] [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: 12/14/2022] [Revised: 01/09/2023] [Accepted: 03/01/2023] [Indexed: 03/08/2023] Open
Abstract
Mitophagy plays an important role in maintaining mitochondrial homeostasis by clearing damaged mitochondria. Sphingosine kinase 2 (SK2), a type of sphingosine kinase, is an important metabolic enzyme involved in generating sphingosine-1-phosphate. Its expression level is elevated in many cancers and is associated with poor clinical outcomes. However, the relationship between SK2 and mitochondrial dysfunction remains unclear. We found that the genetic downregulation of SK2 or treatment with ABC294640, a specific inhibitor of SK2, induced mitophagy and apoptosis in multiple myeloma cell lines. We showed that mitophagy correlates with apoptosis induction and likely occurs through the SET/PP2AC/PARK2 pathway, where inhibiting PP2AC activity may rescue this process. Furthermore, we found that PP2AC and PARK2 form a complex, suggesting that they might regulate mitophagy through protein-protein interactions. Our study demonstrates the important role of SK2 in regulating mitophagy and provides new insights into the mechanism of mitophagy in multiple myeloma.
Collapse
Affiliation(s)
| | | | | | | | | | - Yubin Kang
- Division of Hematologic Malignancies and Cellular Therapy, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| |
Collapse
|
10
|
Fang YZ, Jiang L, He Q, Cao J, Yang B. Commentary: Deubiquitination complex platform: a plausible mechanism for regulating the substrate specificity of deubiquitinating enzymes. Acta Pharm Sin B 2023. [PMID: 37521861 PMCID: PMC10372820 DOI: 10.1016/j.apsb.2023.02.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023] Open
Abstract
Deubiquitinating enzymes (DUBs) or deubiquitinases facilitate the escape of multiple proteins from ubiquitin‒proteasome degradation and are critical for regulating protein expression levels in vivo. Therefore, dissecting the underlying mechanism of DUB recognition is needed to advance the development of drugs related to DUB signaling pathways. To data, extensive studies on the ubiquitin chain specificity of DUBs have been reported, but substrate protein recognition is still not clearly understood. As a breakthrough, the scaffolding role may be significant to substrate protein selectivity. From this perspective, we systematically characterized the scaffolding proteins and complexes contributing to DUB substrate selectivity. Furthermore, we proposed a deubiquitination complex platform (DCP) as a potentially generic mechanism for DUB substrate recognition based on known examples, which might fill the gaps in the understanding of DUB substrate specificity.
Collapse
|
11
|
Pavic K, Gupta N, Omella JD, Derua R, Aakula A, Huhtaniemi R, Määttä JA, Höfflin N, Okkeri J, Wang Z, Kauko O, Varjus R, Honkanen H, Abankwa D, Köhn M, Hytönen VP, Xu W, Nilsson J, Page R, Janssens V, Leitner A, Westermarck J. Structural mechanism for inhibition of PP2A-B56α and oncogenicity by CIP2A. Nat Commun 2023; 14:1143. [PMID: 36854761 PMCID: PMC9974998 DOI: 10.1038/s41467-023-36693-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 02/09/2023] [Indexed: 03/02/2023] Open
Abstract
The protein phosphatase 2A (PP2A) heterotrimer PP2A-B56α is a human tumour suppressor. However, the molecular mechanisms inhibiting PP2A-B56α in cancer are poorly understood. Here, we report molecular level details and structural mechanisms of PP2A-B56α inhibition by an oncoprotein CIP2A. Upon direct binding to PP2A-B56α trimer, CIP2A displaces the PP2A-A subunit and thereby hijacks both the B56α, and the catalytic PP2Ac subunit to form a CIP2A-B56α-PP2Ac pseudotrimer. Further, CIP2A competes with B56α substrate binding by blocking the LxxIxE-motif substrate binding pocket on B56α. Relevant to oncogenic activity of CIP2A across human cancers, the N-terminal head domain-mediated interaction with B56α stabilizes CIP2A protein. Functionally, CRISPR/Cas9-mediated single amino acid mutagenesis of the head domain blunted MYC expression and MEK phosphorylation, and abrogated triple-negative breast cancer in vivo tumour growth. Collectively, we discover a unique multi-step hijack and mute protein complex regulation mechanism resulting in tumour suppressor PP2A-B56α inhibition. Further, the results unfold a structural determinant for the oncogenic activity of CIP2A, potentially facilitating therapeutic modulation of CIP2A in cancer and other diseases.
Collapse
Affiliation(s)
- Karolina Pavic
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520, Turku, Finland
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Nikhil Gupta
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520, Turku, Finland
| | - Judit Domènech Omella
- Laboratory of Protein Phosphorylation & Proteomics, Department of Cellular & Molecular Medicine, University of Leuven (KU Leuven), B-3000, Leuven, Belgium
| | - Rita Derua
- Laboratory of Protein Phosphorylation & Proteomics, Department of Cellular & Molecular Medicine, University of Leuven (KU Leuven), B-3000, Leuven, Belgium
- SyBioMa, University of Leuven (KU Leuven), B-3000, Leuven, Belgium
| | - Anna Aakula
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520, Turku, Finland
| | - Riikka Huhtaniemi
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520, Turku, Finland
| | - Juha A Määttä
- Faculty of Medicine and Health Technology, Tampere University, 33520 Tampere, Finland and Fimlab Laboratories, 33520, Tampere, Finland
| | - Nico Höfflin
- Faculty of Biology, Institute of Biology III, University of Freiburg, 79104, Freiburg, Germany
| | - Juha Okkeri
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520, Turku, Finland
| | - Zhizhi Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Otto Kauko
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520, Turku, Finland
| | - Roosa Varjus
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520, Turku, Finland
| | - Henrik Honkanen
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520, Turku, Finland
| | - Daniel Abankwa
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Maja Köhn
- Faculty of Biology, Institute of Biology III, University of Freiburg, 79104, Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Vesa P Hytönen
- Faculty of Medicine and Health Technology, Tampere University, 33520 Tampere, Finland and Fimlab Laboratories, 33520, Tampere, Finland
| | - Wenqing Xu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Jakob Nilsson
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Rebecca Page
- Department of Chemistry and Biochemistry University of Arizona, Tucson, AZ, USA
| | - Veerle Janssens
- Laboratory of Protein Phosphorylation & Proteomics, Department of Cellular & Molecular Medicine, University of Leuven (KU Leuven), B-3000, Leuven, Belgium
| | - Alexander Leitner
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, 8093, Zurich, Switzerland
| | - Jukka Westermarck
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520, Turku, Finland.
- Institute of Biomedicine, University of Turku, 20520, Turku, Finland.
| |
Collapse
|
12
|
Li Y, Balakrishnan VK, Rowse M, Wu CG, Bravos AP, Yadav VK, Ivarsson YI, Strack S, Novikova IV, Xing Y. Coupling to short linear motifs creates versatile PME-1 activities in PP2A holoenzyme demethylation and inhibition. eLife 2022; 11:79736. [PMID: 35924897 PMCID: PMC9398451 DOI: 10.7554/elife.79736] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 08/03/2022] [Indexed: 11/30/2022] Open
Abstract
Protein phosphatase 2A (PP2A) holoenzymes target broad substrates by recognizing short motifs via regulatory subunits. PP2A methylesterase 1 (PME-1) is a cancer-promoting enzyme and undergoes methylesterase activation upon binding to the PP2A core enzyme. Here, we showed that PME-1 readily demethylates different families of PP2A holoenzymes and blocks substrate recognition in vitro. The high-resolution cryoelectron microscopy structure of a PP2A-B56 holoenzyme–PME-1 complex reveals that PME-1 disordered regions, including a substrate-mimicking motif, tether to the B56 regulatory subunit at remote sites. They occupy the holoenzyme substrate-binding groove and allow large structural shifts in both holoenzyme and PME-1 to enable multipartite contacts at structured cores to activate the methylesterase. B56 interface mutations selectively block PME-1 activity toward PP2A-B56 holoenzymes and affect the methylation of a fraction of total cellular PP2A. The B56 interface mutations allow us to uncover B56-specific PME-1 functions in p53 signaling. Our studies reveal multiple mechanisms of PME-1 in suppressing holoenzyme functions and versatile PME-1 activities derived from coupling substrate-mimicking motifs to dynamic structured cores.
Collapse
Affiliation(s)
- Yitong Li
- Department of Oncology, University of Wisconsin-Madison, Madison, United States
| | | | - Michael Rowse
- Indiana University - Purdue University Columbus, Columbus, United States
| | - Cheng-Guo Wu
- Department of Oncology, University of Wisconsin-Madison, Madison, United States
| | | | - Vikash K Yadav
- 5Department of Chemistry, Uppsala University, Uppsala, Sweden
| | - YIva Ivarsson
- 5Department of Chemistry, Uppsala University, Uppsala, Sweden
| | - Stefan Strack
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, United States
| | - Irina V Novikova
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, United States
| | - Yongna Xing
- Department of Oncology, University of Wisconsin-Madison, Madison, United States
| |
Collapse
|
13
|
Daniel CJ, Pelz C, Wang X, Munks MW, Ko A, Murugan D, Byers SA, Juarez E, Taylor KL, Fan G, Coussens LM, Link JM, Sears RC. T-cell dysfunction upon expression of MYC with altered phosphorylation at Threonine 58 and Serine 62. Mol Cancer Res 2022; 20:1151-1165. [PMID: 35380701 DOI: 10.1158/1541-7786.mcr-21-0560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 03/01/2022] [Accepted: 03/29/2022] [Indexed: 11/16/2022]
Abstract
As a transcription factor that promotes cell growth, proliferation and apoptosis, c-MYC (MYC) expression in the cell is tightly controlled. Disruption of oncogenic signaling pathways in human cancers can increase MYC protein stability, due to altered phosphorylation ratios at two highly conserved sites, Threonine 58 (T58) and Serine 62 (S62). The T58 to Alanine mutant (T58A) of MYC mimics the stabilized, S62 phosphorylated, and highly oncogenic form of MYC. The S62A mutant is also stabilized, lacks phosphorylation at both Serine 62 and Threonine 58, and has been shown to be non-transforming in vitro. However, several regulatory proteins are reported to associate with MYC lacking phosphorylation at S62 and T58, and the role this form of MYC plays in MYC transcriptional output and in vivo oncogenic function is understudied. We generated conditional c-Myc knock-in mice in which the expression of wild-type MYC (MYCWT), the T58A mutant (MYCT58A), or the S62A mutant (MYCS62A) with or without expression of endogenous Myc is controlled by the T-cell-specific Lck-Cre recombinase. MYCT58A expressing mice developed clonal T-cell lymphomas with 100% penetrance and conditional knock-out of endogenous Myc accelerated this lymphomagenesis. In contrast, MYCS62A mice developed clonal T-cell lymphomas at a much lower penetrance, and the loss of endogenous MYC reduced the penetrance while increasing the appearance of a non-transgene driven B-cell lymphoma with splenomegaly. Together, our study highlights the importance of regulated phosphorylation of MYC at T58 and S62 for T-cell transformation. Implications: Dysregulation of phosphorylation at conserved T58 and S62 residues of MYC differentially affects T-cell development and lymphomagenesis.
Collapse
Affiliation(s)
- Colin J Daniel
- Oregon Health & Science University, Portland, OR, United States
| | - Carl Pelz
- Oregon Health & Science University, Portland, OR, United States
| | - Xiaoyan Wang
- Oregon Health & Science University, Portland, Oregon, United States
| | - Michael W Munks
- Oregon Health & Science University, Portland, OR, United States
| | - Aaron Ko
- Oregon Health & Science University, Portland, OR, United States
| | | | - Sarah A Byers
- Oregon Health & Science University, Portland, OR, United States
| | - Eleonora Juarez
- Oregon Health & Science University, Portland, OR, United States
| | - Karyn L Taylor
- Oregon Health & Science University, Portland, OR, United States
| | - Guang Fan
- Oregon Health & Science University Knight Cancer Institute, Portland, OR, United States
| | - Lisa M Coussens
- Oregon Health & Science University, Portland, OR, United States
| | - Jason M Link
- Oregon Health & Science University, Portland, Oregon, United States
| | - Rosalie C Sears
- Oregon Health & Science University, Portland, Oregon, United States
| |
Collapse
|
14
|
Fontana D, Gambacorti-Passerini C, Piazza R. Molecular Pathogenesis of BCR-ABL-Negative Atypical Chronic Myeloid Leukemia. Front Oncol 2021; 11:756348. [PMID: 34858828 PMCID: PMC8631780 DOI: 10.3389/fonc.2021.756348] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 10/22/2021] [Indexed: 11/30/2022] Open
Abstract
Atypical chronic myeloid leukemia is a rare disease whose pathogenesis has long been debated. It currently belongs to the group of myelodysplastic/myeloproliferative disorders. In this review, an overview on the current knowledge about diagnosis, prognosis, and genetics is presented, with a major focus on the recent molecular findings. We describe here the molecular pathogenesis of the disease, focusing on the mechanisms of action of the main mutations as well as on gene expression profiling. We also present the treatment options focusing on emerging targeted therapies.
Collapse
Affiliation(s)
- Diletta Fontana
- Department of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
| | - Carlo Gambacorti-Passerini
- Department of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.,Hematology and Clinical Research Unit, San Gerardo Hospital, Monza, Italy
| | - Rocco Piazza
- Department of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.,Hematology and Clinical Research Unit, San Gerardo Hospital, Monza, Italy.,Bicocca Bioinformatics, Biostatistics and Bioimaging Centre (B4), University of Milano-Bicocca, Milan, Italy
| |
Collapse
|
15
|
Yu H, He J, Liu W, Feng S, Gao L, Xu Y, Zhang Y, Hou X, Zhou Y, Yang L, Wang X. The Transcriptional Coactivator, ALL1-Fused Gene From Chromosome 9, Simultaneously Sustains Hypoxia Tolerance and Metabolic Advantages in Liver Cancer. Hepatology 2021; 74:1952-1970. [PMID: 33928666 DOI: 10.1002/hep.31870] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 03/21/2021] [Accepted: 04/09/2021] [Indexed: 12/25/2022]
Abstract
BACKGROUND AND AIMS Proteins that recognize epigenetic modifications function as mediators to interpret epigenetic codes. Hypoxia response and metabolic rewiring are two major events during cancer progression. However, whether and how the epigenetic regulator integrates hypoxia response and metabolism together remain open for study. APPROACH AND RESULTS We data mined the clinical association of 33 histone lysine acetylation reader proteins with liver cancer and found that ALL1-fused gene from chromosome 9 (AF9) is up-regulated in cancer and correlates with tumor stage and poor prognosis. Conditional deletion of Af9 in mouse liver resulted in decreased tumor formation induced by c-MET proto-oncogene/β-catenin. Loss of AF9 heavily impaired cell proliferation and completely blocked solid tumor formation. We further discovered that AF9 formed a positive feedback circuit with hypoxia-inducible factor 1 alpha (HIF1α) and also stabilized MYC proto-oncogene (cMyc). Mechanically, AF9 interacted with HIF1α and targeted HIF1A promoter whereas AF9 recognized cMyc acetylation at K148, protected cMyc phosphorylation at S62, and then stabilized cMyc, which, in turn, up-regulates phosphofructokinase, platelet expression. Otherwise, knockout of Af9 in mouse hepatocytes increased the infiltration of CD8+ T cells, which is linked to the down-regulation of lactate dehydrogenase A. CONCLUSIONS AF9 is up-regulated to promote gene expression of hypoxia tolerance and glycolysis by simultaneously forming a complex with HIF1α and recognizing acetylated cMyc. Our results establish the oncogenic role of AF9 in human liver cancer, which could be a potential target for designing drugs against liver cancer.
Collapse
Affiliation(s)
- Hua Yu
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, China.,CAS Key Laboratory of Tissue Microenvironment and Tumor, Institute of Nutrition and Health Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Jun He
- Department of General Surgery, Second Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Wei Liu
- Guangdong Provincial Key Laboratory of Liver Disease Research, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Shuya Feng
- CAS Key Laboratory of Tissue Microenvironment and Tumor, Institute of Nutrition and Health Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Li Gao
- CAS Key Laboratory of Tissue Microenvironment and Tumor, Institute of Nutrition and Health Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Yingying Xu
- CAS Key Laboratory of Tissue Microenvironment and Tumor, Institute of Nutrition and Health Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Yawei Zhang
- Department of General Surgery, Second Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Xuyang Hou
- Department of General Surgery, Second Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Yan Zhou
- Department of General Surgery, Second Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Leping Yang
- Department of General Surgery, Second Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Xiongjun Wang
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, China.,CAS Key Laboratory of Tissue Microenvironment and Tumor, Institute of Nutrition and Health Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| |
Collapse
|
16
|
Sun JX, Dou GR, Yang ZY, Liang L, Duan JL, Ruan B, Li MH, Chang TF, Xu XY, Chen JJ, Wang YS, Yan XC, Han H. Notch activation promotes endothelial quiescence by repressing MYC expression via miR-218. MOLECULAR THERAPY-NUCLEIC ACIDS 2021; 25:554-566. [PMID: 34589277 PMCID: PMC8463319 DOI: 10.1016/j.omtn.2021.07.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 07/26/2021] [Indexed: 11/26/2022]
Abstract
After angiogenesis-activated embryonic and early postnatal vascularization, endothelial cells (ECs) in most tissues enter a quiescent state necessary for proper tissue perfusion and EC functions. Notch signaling is essential for maintaining EC quiescence, but the mechanisms of action remain elusive. Here, we show that microRNA-218 (miR-218) is a downstream effector of Notch in quiescent ECs. Notch activation upregulated, while Notch blockade downregulated, miR-218 and its host gene Slit2, likely via transactivation of the Slit2 promoter. Overexpressing miR-218 in human umbilical vein ECs (HUVECs) significantly repressed cell proliferation and sprouting in vitro. Transcriptomics showed that miR-218 overexpression attenuated the MYC proto-oncogene, bHLH transcription factor (MYC, also known as c-myc) signature. MYC overexpression rescued miR-218-mediated proliferation and sprouting defects in HUVECs. MYC was repressed by miR-218 via multiple mechanisms, including reduction of MYC mRNA, repression of MYC translation by targeting heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1), and promoting MYC degradation by targeting EYA3. Inhibition of miR-218 partially reversed Notch-induced repression of HUVEC proliferation and sprouting. In vivo, intravitreal injection of miR-218 reduced retinal EC proliferation accompanied by MYC repression, attenuated pathological choroidal neovascularization, and rescued retinal EC hyper-sprouting induced by Notch blockade. In summary, miR-218 mediates the effect of Notch activation of EC quiescence via MYC and is a potential treatment for angiogenesis-related diseases.
Collapse
Affiliation(s)
- Jia-Xing Sun
- State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an 710032, China.,Department of Ophthalmology, Eye Institute of Chinese PLA, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
| | - Guo-Rui Dou
- Department of Ophthalmology, Eye Institute of Chinese PLA, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
| | - Zi-Yan Yang
- State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an 710032, China
| | - Liang Liang
- State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an 710032, China
| | - Juan-Li Duan
- State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an 710032, China
| | - Bai Ruan
- State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an 710032, China
| | - Man-Hong Li
- Department of Ophthalmology, Eye Institute of Chinese PLA, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
| | - Tian-Fang Chang
- Department of Ophthalmology, Eye Institute of Chinese PLA, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
| | - Xin-Yuan Xu
- State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an 710032, China
| | - Juan-Juan Chen
- State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Yu-Sheng Wang
- Department of Ophthalmology, Eye Institute of Chinese PLA, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
| | - Xian-Chun Yan
- State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an 710032, China
| | - Hua Han
- State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an 710032, China
| |
Collapse
|
17
|
Zhang C, Nie P, Zhou C, Hu Y, Duan S, Gu M, Jiang D, Wang Y, Deng Z, Chen J, Chen S, Wang L. Oxidative stress-induced mitophagy is suppressed by the miR-106b-93-25 cluster in a protective manner. Cell Death Dis 2021; 12:209. [PMID: 33627622 PMCID: PMC7904769 DOI: 10.1038/s41419-021-03484-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 01/15/2021] [Accepted: 01/22/2021] [Indexed: 12/14/2022]
Abstract
Increased reactive oxygen species levels in the mitochondrial matrix can induce Parkin-dependent mitophagy, which selectively degrades dysfunctional mitochondria via the autolysosome pathway. Phosphorylated mitofusin-2 (MFN2), a receptor of parkin RBR E3 ubiquitin-protein ligase (Parkin), interacts with Parkin to promote the ubiquitination of mitochondrial proteins; meanwhile, the mitophagy receptors Optineurin (OPTN) and nuclear dot protein 52 (NDP52) are recruited to damaged mitochondria to promote mitophagy. However, previous studies have not investigated changes in the levels of OPTN, MFN2, and NDP52 during Parkin-mediated mitophagy. Here, we show that mild and sustained hydrogen peroxide (H2O2) stimulation induces Parkin-dependent mitophagy accompanied by downregulation of the mitophagy-associated proteins OPTN, NDP52, and MFN2. We further demonstrate that H2O2 promotes the expression of the miR-106b-93-25 cluster and that miR-106b and miR-93 synergistically inhibit the translation of OPTN, NDP52, and MFN2 by targeting their 3' untranslated regions. We further reveal that compromised phosphorylation of MYC proto-oncogene protein (c-Myc) at threonine 58 (T58) (producing an unstable form of c-Myc) caused by reduced nuclear glycogen synthase kinase-3 beta (GSK3β) levels contributes to the promotion of miR-106b-93-25 cluster expression upon H2O2 induction. Furthermore, miR-106b-mediated and miR-93-mediated inhibition of mitophagy-associated proteins (OPTN, MFN2, and NDP52) restrains cell death by controlling excessive mitophagy. Our data suggest that microRNAs (miRNAs) targeting mitophagy-associated proteins maintain cell survival, which is a novel mechanism of mitophagy control. Thus, our findings provide mechanistic insight into how miRNA-mediated regulation alters the biological process of mitophagy.
Collapse
Affiliation(s)
- Cheng Zhang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, Hubei, China.,Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, China.,Brain Center, Department of Neurosurgery, Zhongnan Hospital, Wuhan University, Wuhan, 430071, Hubei, China
| | - Pengqing Nie
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, Hubei, China.,Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, China.,Department of Burn and Plastic Surgery, Division of Wound Repair, Shenzhen Institute of Translational Medicine, the First Affiliated Hospital, Shenzhen University, Shenzhen, 518035, Guangdong, China
| | - Chunliu Zhou
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, Hubei, China
| | - Yue Hu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, Hubei, China
| | - Suling Duan
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, Hubei, China
| | - Meijia Gu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, Hubei, China
| | - Dongxu Jiang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, Hubei, China
| | - Yunfu Wang
- Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, China
| | - Zixin Deng
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, Hubei, China
| | - Jincao Chen
- Brain Center, Department of Neurosurgery, Zhongnan Hospital, Wuhan University, Wuhan, 430071, Hubei, China
| | - Shi Chen
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, Hubei, China.,Department of Burn and Plastic Surgery, Division of Wound Repair, Shenzhen Institute of Translational Medicine, the First Affiliated Hospital, Shenzhen University, Shenzhen, 518035, Guangdong, China
| | - Lianrong Wang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, Hubei, China. .,Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, China. .,Brain Center, Department of Neurosurgery, Zhongnan Hospital, Wuhan University, Wuhan, 430071, Hubei, China. .,Department of Burn and Plastic Surgery, Division of Wound Repair, Shenzhen Institute of Translational Medicine, the First Affiliated Hospital, Shenzhen University, Shenzhen, 518035, Guangdong, China.
| |
Collapse
|
18
|
Karkache IY, Damodaran JR, Molstad DHH, Bradley EW. Serine/threonine phosphatases in osteoclastogenesis and bone resorption. Gene 2020; 771:145362. [PMID: 33338510 DOI: 10.1016/j.gene.2020.145362] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 11/24/2020] [Accepted: 12/08/2020] [Indexed: 12/27/2022]
Abstract
Maintenance of optimal bone mass is controlled through the concerted functions of several cell types, including bone resorbing osteoclasts. Osteoclasts function to remove calcified tissue during developmental bone modeling, and degrade bone at sites of damage during bone remodeling. Changes to bone homeostasis can arise with alterations in osteoclastogenesis and/or catabolic activity that are not offset by anabolic activity; thus, factors that regulate osteoclastogenesis and bone resorption are of interest to further our understanding of basic bone biology, and as potential targets for therapeutic intervention. Several key cytokines, including RANKL and M-CSF, as well as co-stimulatory factors elicit kinase signaling cascades that promote osteoclastogenesis. These kinase cascades are offset by the action of protein phosphatases, including members of the serine/threonine phosphatase family. Here we review the functions of serine/threonine phosphatases and their control of osteoclast differentiation and function, while highlighting deficiencies in our understanding of this understudied class of proteins within the field.
Collapse
Affiliation(s)
- Ismael Y Karkache
- Department of Orthopedic Surgery, University of Minnesota, Minneapolis, MN 55455, United States
| | - Jeyaram R Damodaran
- Department of Orthopedic Surgery, University of Minnesota, Minneapolis, MN 55455, United States
| | - David H H Molstad
- Department of Orthopedic Surgery, University of Minnesota, Minneapolis, MN 55455, United States
| | - Elizabeth W Bradley
- Department of Orthopedic Surgery, University of Minnesota, Minneapolis, MN 55455, United States; Stem Cell Institute, University of Minnesota, Minneapolis, MN 55455, United States.
| |
Collapse
|
19
|
Rezcallah MC, Al-Mazi T, Ammit AJ. Cataloguing the phosphorylation sites of tristetraprolin (TTP): Functional implications for inflammatory diseases. Cell Signal 2020; 78:109868. [PMID: 33276085 DOI: 10.1016/j.cellsig.2020.109868] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/29/2020] [Accepted: 11/29/2020] [Indexed: 01/10/2023]
Abstract
Tristetraprolin (TTP) is a destabilizing mRNA binding protein known to regulate gene expression of a wide variety of targets, including those that control inflammation. TTP expression, regulation and function is controlled by phosphorylation. While the importance of key serine (S) sites (S52 and S178 in mice and S186 in humans) has been recognized, other sites on the hyperphosphorylated TTP protein have more recently emerged as playing an important role in regulating cellular signalling and downstream functions of TTP. In order to propel investigation of TTP and fully exploit its potential as a drug target in inflammatory disease, this review will catalogue TTP phosphorylation sites in both the murine and human TTP protein, the known and unknown roles and functions of these sites, the kinases and phosphatases that act upon TTP and overview methodological approaches to increase our knowledge of this important protein regulated by phosphorylation.
Collapse
Affiliation(s)
- Maria C Rezcallah
- Woolcock Emphysema Centre, Woolcock Institute of Medical Research, University of Sydney, NSW, Australia; School of Life Sciences, Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia
| | - Trisha Al-Mazi
- Woolcock Emphysema Centre, Woolcock Institute of Medical Research, University of Sydney, NSW, Australia; School of Life Sciences, Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia
| | - Alaina J Ammit
- Woolcock Emphysema Centre, Woolcock Institute of Medical Research, University of Sydney, NSW, Australia; School of Life Sciences, Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia.
| |
Collapse
|
20
|
Abstract
Manipulation of the host cell is a crucial part of life for many intracellular organisms. We have recently come to appreciate the extent to which the intracellular pathogen Toxoplasma gondii reprograms its host cell, and this is illustrated by the marked upregulation of the central regulator c-Myc, an oncogene that coordinates myriad cellular functions. In an effort to identify an effector protein capable of regulating c-Myc, our laboratory constructed a screen for mutant parasites unable to accomplish this upregulation. Interestingly, this screen identified numerous components of a complex located in/on the parasitophorous vacuole membrane necessary to translocate Toxoplasma proteins out into the host cytosol, but it never identified a specific effector protein. Thus, how the parasite upregulates c-Myc has largely been a mystery. Previously, the Toxoplasma dense granule protein GRA16 has been described to bind to one isoform of PP2A-B, a regulatory subunit that coordinates the activity of the catalytic protein phosphatase PP2A. As other PP2A subunits have been reported to target PP2A protein phosphatase activity to c-Myc, subsequently leading to c-Myc destabilization, we examined whether GRA16 has an impact on host c-Myc accumulation. Expression of Toxoplasma's GRA16 protein in Neospora caninum, a close relative of Toxoplasma that does not naturally upregulate host c-Myc, conferred the ability on Neospora to do this now. Further support was obtained by deleting the GRA16 gene from Toxoplasma and observing a severely diminished ability of Toxoplasma tachyzoites to upregulate host c-Myc. Thus, GRA16 is an effector protein central to Toxoplasma's ability to upregulate host c-Myc.IMPORTANCE The proto-oncogene c-Myc plays a crucial role in the growth and division of many animal cells. Previous studies have identified an active upregulation of c-Myc by Toxoplasma tachyzoites, suggesting the existence of one or more exported "effector" proteins. The identity of such an effector, however, has not previously been known. Here, we show that a previously known secreted protein, GRA16, plays a crucial role in c-Myc upregulation. This finding will enable further dissection of the precise mechanism and role of c-Myc upregulation in Toxoplasma-infected cells.
Collapse
Affiliation(s)
- Michael W Panas
- Department of Microbiology and Immunology, Stanford School of Medicine, Stanford, California, USA
| | - John C Boothroyd
- Department of Microbiology and Immunology, Stanford School of Medicine, Stanford, California, USA
| |
Collapse
|
21
|
Mandemaker IK, Zhou D, Bruens ST, Dekkers DH, Verschure PJ, Edupuganti RR, Meshorer E, Demmers JAA, Marteijn JA. Histone H1 eviction by the histone chaperone SET reduces cell survival following DNA damage. J Cell Sci 2020; 133:jcs235473. [PMID: 32184266 DOI: 10.1242/jcs.235473] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 02/27/2020] [Indexed: 08/31/2023] Open
Abstract
Many chromatin remodeling and modifying proteins are involved in the DNA damage response, where they stimulate repair or induce DNA damage signaling. Interestingly, we identified that downregulation of the histone H1 (H1)-interacting protein SET results in increased resistance to a wide variety of DNA damaging agents. We found that this increased resistance does not result from alleviation of an inhibitory effect of SET on DNA repair but, rather, is the consequence of a suppressed apoptotic response to DNA damage. Furthermore, we provide evidence that the histone chaperone SET is responsible for the eviction of H1 from chromatin. Knockdown of H1 in SET-depleted cells resulted in re-sensitization of cells to DNA damage, suggesting that the increased DNA damage resistance in SET-depleted cells is the result of enhanced retention of H1 on chromatin. Finally, clonogenic survival assays showed that SET and p53 act epistatically in the attenuation of DNA damage-induced cell death. Taken together, our data indicate a role for SET in the DNA damage response as a regulator of cell survival following genotoxic stress.This article has an associated First Person interview with the first author of the paper.
Collapse
Affiliation(s)
- Imke K Mandemaker
- Erasmus MC, University Medical Center Rotterdam, Department of Molecular Genetics, Oncode Institute, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
| | - Di Zhou
- Erasmus MC, University Medical Center Rotterdam, Department of Molecular Genetics, Oncode Institute, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
| | - Serena T Bruens
- Erasmus MC, University Medical Center Rotterdam, Department of Molecular Genetics, Oncode Institute, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
| | - Dick H Dekkers
- Proteomics Center, Erasmus University Medical Center, 3015 CN Rotterdam, The Netherlands
| | - Pernette J Verschure
- Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Raghu R Edupuganti
- The Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra campus, 91904 Jerusalem, Israel
| | - Eran Meshorer
- The Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra campus, 91904 Jerusalem, Israel
- The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Jeroen A A Demmers
- Proteomics Center, Erasmus University Medical Center, 3015 CN Rotterdam, The Netherlands
| | - Jurgen A Marteijn
- Erasmus MC, University Medical Center Rotterdam, Department of Molecular Genetics, Oncode Institute, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
| |
Collapse
|
22
|
Leonard D, Huang W, Izadmehr S, O'Connor CM, Wiredja DD, Wang Z, Zaware N, Chen Y, Schlatzer DM, Kiselar J, Vasireddi N, Schüchner S, Perl AL, Galsky MD, Xu W, Brautigan DL, Ogris E, Taylor DJ, Narla G. Selective PP2A Enhancement through Biased Heterotrimer Stabilization. Cell 2020; 181:688-701.e16. [PMID: 32315618 DOI: 10.1016/j.cell.2020.03.038] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 12/04/2019] [Accepted: 03/17/2020] [Indexed: 12/15/2022]
Abstract
Impairment of protein phosphatases, including the family of serine/threonine phosphatases designated PP2A, is essential for the pathogenesis of many diseases, including cancer. The ability of PP2A to dephosphorylate hundreds of proteins is regulated by over 40 specificity-determining regulatory "B" subunits that compete for assembly and activation of heterogeneous PP2A heterotrimers. Here, we reveal how a small molecule, DT-061, specifically stabilizes the B56α-PP2A holoenzyme in a fully assembled, active state to dephosphorylate selective substrates, such as its well-known oncogenic target, c-Myc. Our 3.6 Å structure identifies molecular interactions between DT-061 and all three PP2A subunits that prevent dissociation of the active enzyme and highlight inherent mechanisms of PP2A complex assembly. Thus, our findings provide fundamental insights into PP2A complex assembly and regulation, identify a unique interfacial stabilizing mode of action for therapeutic targeting, and aid in the development of phosphatase-based therapeutics tailored against disease specific phospho-protein targets.
Collapse
Affiliation(s)
- Daniel Leonard
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA; Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Wei Huang
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Sudeh Izadmehr
- Division of Hematology and Medical Oncology, Department of Medicine, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Pathology, Molecular and Cell-Based Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Caitlin M O'Connor
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48105, USA; Rogel Cancer Center, University of Michigan, Ann Arbor, MI 48109, USA
| | - Danica D Wiredja
- Department of Nutrition, Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Zhizhi Wang
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Nilesh Zaware
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Yinghua Chen
- PEPCC Facility, Case Western Reserve University, 10900 Euclid Ave., Cleveland, OH 44106, USA
| | - Daniela M Schlatzer
- Department of Nutrition, Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Janna Kiselar
- Department of Nutrition, Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Nikhil Vasireddi
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Stefan Schüchner
- Center for Medical Biochemistry, Max Perutz Labs, Medical University of Vienna, Dr. Bohr-Gasse 9/2, Vienna 1030, Austria
| | - Abbey L Perl
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Matthew D Galsky
- Division of Hematology and Medical Oncology, Department of Medicine, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Wenqing Xu
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - David L Brautigan
- Department of Microbiology, Immunology, and Cancer Biology, Center for Cell Signaling, University of Virginia, Charlottesville, VA 22903, USA
| | - Egon Ogris
- Center for Medical Biochemistry, Max Perutz Labs, Medical University of Vienna, Dr. Bohr-Gasse 9/2, Vienna 1030, Austria
| | - Derek J Taylor
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA; Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106, USA.
| | - Goutham Narla
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48105, USA; Rogel Cancer Center, University of Michigan, Ann Arbor, MI 48109, USA.
| |
Collapse
|
23
|
Abstract
MYC is a master transcriptional regulator that controls almost all cellular processes. Over the last several decades, researchers have strived to define the context-dependent transcriptional gene programs that are controlled by MYC, as well as the mechanisms that regulate MYC function, in an effort to better understand the contribution of this oncoprotein to cancer progression. There are a wealth of data indicating that deregulation of MYC activity occurs in a large number of cancers and significantly contributes to disease progression, metastatic potential, and therapeutic resistance. Although the therapeutic targeting of MYC in cancer is highly desirable, there remain substantial structural and functional challenges that have impeded direct MYC-targeted drug development and efficacy. While efforts to drug the ‘undruggable’ may seem futile given these challenges and considering the broad reach of MYC, significant strides have been made to identify points of regulation that can be exploited for therapeutic purposes. These include targeting the deregulation of MYC transcription in cancer through small-molecule inhibitors that induce epigenetic silencing or that regulate the G-quadruplex structures within the MYC promoter. Alternatively, compounds that disrupt the DNA-binding activities of MYC have been the long-standing focus of many research groups, since this method would prevent downstream MYC oncogenic activities regardless of upstream alterations. Finally, proteins involved in the post-translational regulation of MYC have been identified as important surrogate targets to reduce MYC activity downstream of aberrant cell stimulatory signals. Given the complex regulation of the MYC signaling pathway, a combination of these approaches may provide the most durable response, but this has yet to be shown. Here, we provide a comprehensive overview of the different therapeutic strategies being employed to target oncogenic MYC function, with a focus on post-translational mechanisms.
Collapse
|
24
|
Farrington CC, Yuan E, Mazhar S, Izadmehr S, Hurst L, Allen-Petersen BL, Janghorban M, Chung E, Wolczanski G, Galsky M, Sears R, Sangodkar J, Narla G. Protein phosphatase 2A activation as a therapeutic strategy for managing MYC-driven cancers. J Biol Chem 2020. [DOI: 10.1016/s0021-9258(17)49933-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|
25
|
Farrington CC, Yuan E, Mazhar S, Izadmehr S, Hurst L, Allen-Petersen BL, Janghorban M, Chung E, Wolczanski G, Galsky M, Sears R, Sangodkar J, Narla G. Protein phosphatase 2A activation as a therapeutic strategy for managing MYC-driven cancers. J Biol Chem 2019; 295:757-770. [PMID: 31822503 DOI: 10.1074/jbc.ra119.011443] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 12/04/2019] [Indexed: 12/14/2022] Open
Abstract
The tumor suppressor protein phosphatase 2A (PP2A) is a serine/threonine phosphatase whose activity is inhibited in most human cancers. One of the best-characterized PP2A substrates is MYC proto-oncogene basic helix-loop-helix transcription factor (MYC), whose overexpression is commonly associated with aggressive forms of this disease. PP2A directly dephosphorylates MYC, resulting in its degradation. To explore the therapeutic potential of direct PP2A activation in a diverse set of MYC-driven cancers, here we used biochemical assays, recombinant cell lines, gene expression analyses, and immunohistochemistry to evaluate a series of first-in-class small-molecule activators of PP2A (SMAPs) in Burkitt lymphoma, KRAS-driven non-small cell lung cancer, and triple-negative breast cancer. In all tested models of MYC-driven cancer, the SMAP treatment rapidly and persistently inhibited MYC expression through proteasome-mediated degradation, inhibition of MYC transcriptional activity, decreased cancer cell proliferation, and tumor growth inhibition. Importantly, we generated a series of cell lines expressing PP2A-dependent phosphodegron variants of MYC and demonstrated that the antitumorigenic activity of SMAPs depends on MYC degradation. Collectively, the findings presented here indicate a pharmacologically tractable approach to drive MYC degradation by using SMAPs for the management of a broad range of MYC-driven cancers.
Collapse
Affiliation(s)
| | - Eric Yuan
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio 44106
| | - Sahar Mazhar
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio 44106
| | - Sudeh Izadmehr
- Department of Medicine, Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Lauren Hurst
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48105
| | - Brittany L Allen-Petersen
- Department of Molecular and Medical Genetics, Oregon Health and Sciences University, Portland, Oregon 97239
| | - Mahnaz Janghorban
- Department of Molecular and Medical Genetics, Oregon Health and Sciences University, Portland, Oregon 97239
| | - Eric Chung
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio 44106
| | - Grace Wolczanski
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48105
| | - Matthew Galsky
- Department of Medicine, Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Rosalie Sears
- Department of Molecular and Medical Genetics, Oregon Health and Sciences University, Portland, Oregon 97239
| | - Jaya Sangodkar
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48105
| | - Goutham Narla
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48105
| |
Collapse
|
26
|
Nader CP, Cidem A, Verrills NM, Ammit AJ. Protein phosphatase 2A (PP2A): a key phosphatase in the progression of chronic obstructive pulmonary disease (COPD) to lung cancer. Respir Res 2019; 20:222. [PMID: 31623614 PMCID: PMC6798356 DOI: 10.1186/s12931-019-1192-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Accepted: 09/20/2019] [Indexed: 02/06/2023] Open
Abstract
Lung cancer (LC) has the highest relative risk of development as a comorbidity of chronic obstructive pulmonary disease (COPD). The molecular mechanisms that mediate chronic inflammation and lung function impairment in COPD have been identified in LC. This suggests the two diseases are more linked than once thought. Emerging data in relation to a key phosphatase, protein phosphatase 2A (PP2A), and its regulatory role in inflammatory and tumour suppression in both disease settings suggests that it may be critical in the progression of COPD to LC. In this review, we uncover the importance of the functional and active PP2A holoenzyme in the context of both diseases. We describe PP2A inactivation via direct and indirect means and explore the actions of two key PP2A endogenous inhibitors, cancerous inhibitor of PP2A (CIP2A) and inhibitor 2 of PP2A (SET), and the role they play in COPD and LC. We explain how dysregulation of PP2A in COPD creates a favourable inflammatory micro-environment and promotes the initiation and progression of tumour pathogenesis. Finally, we highlight PP2A as a druggable target in the treatment of COPD and LC and demonstrate the potential of PP2A re-activation as a strategy to halt COPD disease progression to LC. Although further studies are required to elucidate if PP2A activity in COPD is a causal link for LC progression, studies focused on the potential of PP2A reactivating agents to reduce the risk of LC formation in COPD patients will be pivotal in improving clinical outcomes for both COPD and LC patients in the future.
Collapse
Affiliation(s)
- Cassandra P Nader
- Woolcock Emphysema Centre, Woolcock Institute of Medical Research, University of Sydney, Sydney, NSW, Australia
| | - Aylin Cidem
- Woolcock Emphysema Centre, Woolcock Institute of Medical Research, University of Sydney, Sydney, NSW, Australia
| | - Nicole M Verrills
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, 2308, Australia
- Priority Research Centre for Cancer Research, Innovation & Translation, Faculty of Health & Medicine, Hunter Medical Research Institute, New Lambton Heights, NSW, 2305, Australia
| | - Alaina J Ammit
- Woolcock Emphysema Centre, Woolcock Institute of Medical Research, University of Sydney, Sydney, NSW, Australia.
- School of Life Sciences, Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia.
| |
Collapse
|
27
|
Murga-Zamalloa C, Inamdar KV, Wilcox RA. The role of aurora A and polo-like kinases in high-risk lymphomas. Blood Adv 2019; 3:1778-1787. [PMID: 31186254 PMCID: PMC6560346 DOI: 10.1182/bloodadvances.2019000232] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 05/16/2019] [Indexed: 02/06/2023] Open
Abstract
High-risk lymphomas (HRLs) are associated with dismal outcomes and remain a therapeutic challenge. Recurrent genetic and molecular alterations, including c-myc expression and aurora A kinase (AAK) and polo-like kinase-1 (PLK1) activation, promote cell proliferation and contribute to the highly aggressive natural history associated with these lymphoproliferative disorders. In addition to its canonical targets regulating mitosis, the AAK/PLK1 axis directly regulates noncanonical targets, including c-myc. Recent studies demonstrate that HRLs, including T-cell lymphomas and many highly aggressive B-cell lymphomas, are dependent upon the AAK/PLK1 axis. Therefore, the AAK/PLK1 axis has emerged as an attractive therapeutic target in these lymphomas. In addition to reviewing these recent findings, we summarize the rationale for targeting AAK/PLK1 in high-risk and c-myc-driven lymphoproliferative disorders.
Collapse
Affiliation(s)
- Carlos Murga-Zamalloa
- Division of Hematology-Oncology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI; and
| | | | - Ryan A Wilcox
- Division of Hematology-Oncology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI; and
| |
Collapse
|
28
|
Parang B, Thompson JJ, Williams CS. Blood Vessel Epicardial Substance (BVES) in junctional signaling and cancer. Tissue Barriers 2018; 6:1-12. [PMID: 30307367 DOI: 10.1080/21688370.2018.1499843] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Blood vessel epicardial substance (BVES) is a tight-junction associated protein that was originally discovered from a cDNA screen of the developing heart. Research over the last decade has shown that not only is BVES is expressed in cardiac and skeletal tissue, but BVES is also is expressed throughout the gastrointestinal epithelium. Mice lacking BVES sustain worse intestinal injury and inflammation. Furthermore, BVES is suppressed in gastrointestinal cancers, and mouse modeling has shown that loss of BVES promotes tumor formation. Recent work from multiple laboratories has revealed that BVES can regulate several molecular pathways, including cAMP, WNT, and promoting the degradation of the oncogene, c-Myc. This review will summarize our current understanding of how BVES regulates the intestinal epithelium and discuss how BVES functions at the molecular level to preserve epithelial phenotypes and suppress tumorigenesis.
Collapse
Affiliation(s)
- Bobak Parang
- a Department of Medicine , Cornell University , New York , NY , USA
| | - Joshua J Thompson
- b Department of Medicine, Division of Gastroenterology , Vanderbilt University , Nashville , TN , USA
| | - Christopher S Williams
- b Department of Medicine, Division of Gastroenterology , Vanderbilt University , Nashville , TN , USA.,c Veterans Affairs Tennessee Valley Health Care System , Nashville , TN , USA
| |
Collapse
|
29
|
Zhang L, Zhou H, Li X, Vartuli RL, Rowse M, Xing Y, Rudra P, Ghosh D, Zhao R, Ford HL. Eya3 partners with PP2A to induce c-Myc stabilization and tumor progression. Nat Commun 2018; 9:1047. [PMID: 29535359 PMCID: PMC5849647 DOI: 10.1038/s41467-018-03327-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 02/02/2018] [Indexed: 12/13/2022] Open
Abstract
Eya genes encode a unique family of multifunctional proteins that serve as transcriptional co-activators and as haloacid dehalogenase-family Tyr phosphatases. Intriguingly, the N-terminal domain of Eyas, which does not share sequence similarity to any known phosphatases, contains a separable Ser/Thr phosphatase activity. Here, we demonstrate that the Ser/Thr phosphatase activity of Eya is not intrinsic, but arises from its direct interaction with the protein phosphatase 2A (PP2A)-B55α holoenzyme. Importantly, Eya3 alters the regulation of c-Myc by PP2A, increasing c-Myc stability by enabling PP2A-B55α to dephosphorylate pT58, in direct contrast to the previously described PP2A-B56α-mediated dephosphorylation of pS62 and c-Myc destabilization. Furthermore, Eya3 and PP2A-B55α promote metastasis in a xenograft model of breast cancer, opposing the canonical tumor suppressive function of PP2A-B56α. Our study identifies Eya3 as a regulator of PP2A, a major cellular Ser/Thr phosphatase, and uncovers a mechanism of controlling the stability of a critical oncogene, c-Myc.
Collapse
Affiliation(s)
- Lingdi Zhang
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver Anschutz Medical Campus, Aurora, 80045, CO, USA
| | - Hengbo Zhou
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, 80045, CO, USA
- Cancer Biology Program, University of Colorado Anschutz Medical Campus, Aurora, 80045, CO, USA
| | - Xueni Li
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver Anschutz Medical Campus, Aurora, 80045, CO, USA
| | - Rebecca L Vartuli
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, 80045, CO, USA
- Molecular Biology Program, University of Colorado Anschutz Medical Campus, Aurora, 80045, CO, USA
| | - Michael Rowse
- McArdle Laboratory for Cancer Research, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, 53705, WI, USA
| | - Yongna Xing
- McArdle Laboratory for Cancer Research, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, 53705, WI, USA
| | - Pratyaydipta Rudra
- Department of Biostatistics and Informatics, University of Colorado Anschutz Medical Campus, Aurora, 80045, CO, USA
| | - Debashis Ghosh
- Department of Biostatistics and Informatics, University of Colorado Anschutz Medical Campus, Aurora, 80045, CO, USA
| | - Rui Zhao
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver Anschutz Medical Campus, Aurora, 80045, CO, USA.
- Molecular Biology Program, University of Colorado Anschutz Medical Campus, Aurora, 80045, CO, USA.
| | - Heide L Ford
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver Anschutz Medical Campus, Aurora, 80045, CO, USA.
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, 80045, CO, USA.
- Cancer Biology Program, University of Colorado Anschutz Medical Campus, Aurora, 80045, CO, USA.
- Molecular Biology Program, University of Colorado Anschutz Medical Campus, Aurora, 80045, CO, USA.
| |
Collapse
|
30
|
Protein Phosphatase 2A in the Regulation of Wnt Signaling, Stem Cells, and Cancer. Genes (Basel) 2018; 9:genes9030121. [PMID: 29495399 PMCID: PMC5867842 DOI: 10.3390/genes9030121] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 02/16/2018] [Accepted: 02/21/2018] [Indexed: 12/21/2022] Open
Abstract
Protein phosphorylation is a ubiquitous cellular process that allows for the nuanced and reversible regulation of protein activity. Protein phosphatase 2A (PP2A) is a heterotrimeric serine-threonine phosphatase—composed of a structural, regulatory, and catalytic subunit—that controls a variety of cellular events via protein dephosphorylation. While much is known about PP2A and its basic biochemistry, the diversity of its components—especially the multitude of regulatory subunits—has impeded the determination of PP2A function. As a consequence of this complexity, PP2A has been shown to both positively and negatively regulate signaling networks such as the Wnt pathway. Wnt signaling modulates major developmental processes, and is a dominant mediator of stem cell self-renewal, cell fate, and cancer stem cells. Because PP2A affects Wnt signaling both positively and negatively and at multiple levels, further understanding of this complex dynamic may ultimately provide insight into stem cell biology and how to better treat cancers that result from alterations in Wnt signaling. This review will summarize literature that implicates PP2A as a tumor suppressor, explore PP2A mutations identified in human malignancy, and focus on PP2A in the regulation of Wnt signaling and stem cells so as to better understand how aberrancy in this pathway can contribute to tumorigenesis.
Collapse
|
31
|
Mao Z, Liu C, Lin X, Sun B, Su C. PPP2R5A: A multirole protein phosphatase subunit in regulating cancer development. Cancer Lett 2018; 414:222-229. [DOI: 10.1016/j.canlet.2017.11.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 11/20/2017] [Accepted: 11/21/2017] [Indexed: 12/21/2022]
|
32
|
Zhao H, Li D, Zhang B, Qi Y, Diao Y, Zhen Y, Shu X. PP2A as the Main Node of Therapeutic Strategies and Resistance Reversal in Triple-Negative Breast Cancer. Molecules 2017; 22:molecules22122277. [PMID: 29261144 PMCID: PMC6149800 DOI: 10.3390/molecules22122277] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 12/07/2017] [Accepted: 12/19/2017] [Indexed: 12/31/2022] Open
Abstract
Triple negative breast cancer (TNBC), is defined as a type of tumor lacking the expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2). The ER, PR and HER2 are usually the molecular therapeutic targets for breast cancers, but they are ineffective for TNBC because of their negative expressions, so chemotherapy is currently the main treatment strategy in TNBC. However, drug resistance remains a major impediment to TNBC chemotherapeutic treatment. Recently, the protein phosphatase 2A (PP2A) has been found to regulate the phosphorylation of some substrates involved in the relevant target of TNBC, such as cell cycle control, DNA damage responses, epidermal growth factor receptor, immune modulation and cell death resistance, which may be the effective therapeutic strategies or influence drug sensitivity to TNBCs. Furthermore, PP2A has also been found that could induce ER re-expression in ER-negative breast cancer cells, and which suggests PP2A could promote the sensitivity of tamoxifen to TNBCs as a resistance reversal agent. In this review, we will summarize the potential therapeutic value of PP2A as the main node in developing targeting agents, disrupting resistance or restoring drug sensitivity in TNBC.
Collapse
Affiliation(s)
- Henan Zhao
- Department of Pathophysiology, Dalian Medical University, Dalian 116044, China.
| | - Duojiao Li
- Kamp Pharmaceutical Co. Ltd., Changsha 410008, China.
| | - Baojing Zhang
- College of Pharmacy, Dalian Medical University, Dalian 116044, China.
| | - Yan Qi
- College of Pharmacy, Dalian Medical University, Dalian 116044, China.
| | - Yunpeng Diao
- College of Pharmacy, Dalian Medical University, Dalian 116044, China.
| | - Yuhong Zhen
- College of Pharmacy, Dalian Medical University, Dalian 116044, China.
| | - Xiaohong Shu
- College of Pharmacy, Dalian Medical University, Dalian 116044, China.
| |
Collapse
|
33
|
Janghorban M, Langer EM, Wang X, Zachman D, Daniel CJ, Hooper J, Fleming WH, Agarwal A, Sears RC. The tumor suppressor phosphatase PP2A-B56α regulates stemness and promotes the initiation of malignancies in a novel murine model. PLoS One 2017; 12:e0188910. [PMID: 29190822 PMCID: PMC5708644 DOI: 10.1371/journal.pone.0188910] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 11/15/2017] [Indexed: 01/13/2023] Open
Abstract
Protein phosphatase 2A (PP2A) is a ubiquitously expressed Serine-Threonine phosphatase mediating 30–50% of protein phosphatase activity. PP2A functions as a heterotrimeric complex, with the B subunits directing target specificity to regulate the activity of many key pathways that control cellular phenotypes. PP2A-B56α has been shown to play a tumor suppressor role and to negatively control c-MYC stability and activity. Loss of B56α promotes cellular transformation, likely at least in part through its regulation of c-MYC. Here we report generation of a B56α hypomorph mouse with very low B56α expression that we used to study the physiologic activity of the PP2A-B56α phosphatase. The predominant phenotype we observed in mice with B56α deficiency in the whole body was spontaneous skin lesion formation with hyperproliferation of the epidermis, hair follicles and sebaceous glands. Increased levels of c-MYC phosphorylation on Serine62 and c-MYC activity were observed in the skin lesions of the B56αhm/hm mice. B56α deficiency was found to increase the number of skin stem cells, and consistent with this, papilloma initiation was accelerated in a carcinogenesis model. Further analysis of additional tissues revealed increased inflammation in spleen, liver, lung, and intestinal lymph nodes as well as in the skin lesions, resembling elevated extramedullary hematopoiesis phenotypes in the B56αhm/hm mice. We also observed an increase in the clonogenicity of bone marrow stem cells in B56αhm/hm mice. Overall, this model suggests that B56α is important for stem cells to maintain homeostasis and that B56α loss leading to increased activity of important oncogenes, including c-MYC, can result in aberrant cell growth and increased stem cells that can contribute to the initiation of malignancy.
Collapse
Affiliation(s)
- Mahnaz Janghorban
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Ellen M. Langer
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Xiaoyan Wang
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Derek Zachman
- Papé Family Pediatric Research Institute, Oregon Stem Cell Center, Department of Pediatrics, Portland, Oregon, United States of America
| | - Colin J. Daniel
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Jody Hooper
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - William H. Fleming
- Papé Family Pediatric Research Institute, Oregon Stem Cell Center, Department of Pediatrics, Portland, Oregon, United States of America
- Knight Cancer Institute, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Anupriya Agarwal
- Knight Cancer Institute, Oregon Health & Science University, Portland, Oregon, United States of America
- Division of Hematology & Medical Oncology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Rosalie C. Sears
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, United States of America
- Knight Cancer Institute, Oregon Health & Science University, Portland, Oregon, United States of America
- Brenden-Colson Center for Pancreatic Care, Oregon Health and Science University, Portland, Oregon, United States of America
- * E-mail:
| |
Collapse
|
34
|
Wiredja DD, Ayati M, Mazhar S, Sangodkar J, Maxwell S, Schlatzer D, Narla G, Koyutürk M, Chance MR. Phosphoproteomics Profiling of Nonsmall Cell Lung Cancer Cells Treated with a Novel Phosphatase Activator. Proteomics 2017; 17. [PMID: 28961369 DOI: 10.1002/pmic.201700214] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 09/07/2017] [Indexed: 01/17/2023]
Abstract
Activation of protein phosphatase 2A (PP2A) is a promising anticancer therapeutic strategy, as this tumor suppressor has the ability to coordinately downregulate multiple pathways involved in the regulation of cellular growth and proliferation. In order to understand the systems-level perturbations mediated by PP2A activation, we carried out mass spectrometry-based phosphoproteomic analysis of two KRAS mutated non-small cell lung cancer (NSCLC) cell lines (A549 and H358) treated with a novel small molecule activator of PP2A (SMAP). Overall, this permitted quantification of differential signaling across over 1600 phosphoproteins and 3000 phosphosites. Kinase activity assessment and pathway enrichment implicate collective downregulation of RAS and cell cycle kinases in the case of both cell lines upon PP2A activation. However, the effects on RAS-related signaling are attenuated for A549 compared to H358, while the effects on cell cycle-related kinases are noticeably more prominent in A549. Network-based analyses and validation experiments confirm these detailed differences in signaling. These studies reveal the power of phosphoproteomics studies, coupled to computational systems biology, to elucidate global patterns of phosphatase activation and understand the variations in response to PP2A activation across genetically similar NSCLC cell lines.
Collapse
Affiliation(s)
- Danica D Wiredja
- Center for Proteomics and Bioinformatics, Department of Nutrition, Case Western Reserve University, Cleveland, OH, USA
| | - Marzieh Ayati
- Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, OH, USA
| | - Sahar Mazhar
- Department of Pathology, Case Western Reserve University,, Cleveland, OH, USA
| | - Jaya Sangodkar
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, NY, USA
| | - Sean Maxwell
- Center for Proteomics and Bioinformatics, Department of Nutrition, Case Western Reserve University, Cleveland, OH, USA
| | - Daniela Schlatzer
- Center for Proteomics and Bioinformatics, Department of Nutrition, Case Western Reserve University, Cleveland, OH, USA
| | - Goutham Narla
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, USA
| | - Mehmet Koyutürk
- Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, OH, USA
| | - Mark R Chance
- Center for Proteomics and Bioinformatics, Department of Nutrition, Case Western Reserve University, Cleveland, OH, USA.,Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, USA
| |
Collapse
|
35
|
Wang J, Okkeri J, Pavic K, Wang Z, Kauko O, Halonen T, Sarek G, Ojala PM, Rao Z, Xu W, Westermarck J. Oncoprotein CIP2A is stabilized via interaction with tumor suppressor PP2A/B56. EMBO Rep 2017; 18:437-450. [PMID: 28174209 DOI: 10.15252/embr.201642788] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 12/20/2016] [Accepted: 01/09/2017] [Indexed: 01/20/2023] Open
Abstract
Protein phosphatase 2A (PP2A) is a critical human tumor suppressor. Cancerous inhibitor of PP2A (CIP2A) supports the activity of several critical cancer drivers (Akt, MYC, E2F1) and promotes malignancy in most cancer types via PP2A inhibition. However, the 3D structure of CIP2A has not been solved, and it remains enigmatic how it interacts with PP2A. Here, we show by yeast two-hybrid assays, and subsequent validation experiments, that CIP2A forms homodimers. The homodimerization of CIP2A is confirmed by solving the crystal structure of an N-terminal CIP2A fragment (amino acids 1-560) at 3.0 Å resolution, and by subsequent structure-based mutational analyses of the dimerization interface. We further describe that the CIP2A dimer interacts with the PP2A subunits B56α and B56γ. CIP2A binds to the B56 proteins via a conserved N-terminal region, and dimerization promotes B56 binding. Intriguingly, inhibition of either CIP2A dimerization or B56α/γ expression destabilizes CIP2A, indicating opportunities for controlled degradation. These results provide the first structure-function analysis of the interaction of CIP2A with PP2A/B56 and have direct implications for its targeting in cancer therapy.
Collapse
Affiliation(s)
- Jiao Wang
- Department of Biological Structure, University of Washington, Seattle, WA, USA.,College of Life Sciences, Nankai University, Tianjin, China
| | - Juha Okkeri
- Turku Centre for Biotechnology, University of Turku, Turku, Finland.,Åbo Akademi University, Turku, Finland
| | - Karolina Pavic
- Turku Centre for Biotechnology, University of Turku, Turku, Finland.,Åbo Akademi University, Turku, Finland
| | - Zhizhi Wang
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Otto Kauko
- Turku Centre for Biotechnology, University of Turku, Turku, Finland.,Åbo Akademi University, Turku, Finland.,Department of Pathology, University of Turku, Turku, Finland
| | - Tuuli Halonen
- Turku Centre for Biotechnology, University of Turku, Turku, Finland.,Åbo Akademi University, Turku, Finland
| | - Grzegorz Sarek
- Research Programs Unit, Translational Cancer Biology, University of Helsinki, Helsinki, Finland
| | - Päivi M Ojala
- Research Programs Unit, Translational Cancer Biology, University of Helsinki, Helsinki, Finland
| | - Zihe Rao
- College of Life Sciences, Nankai University, Tianjin, China
| | - Wenqing Xu
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Jukka Westermarck
- Turku Centre for Biotechnology, University of Turku, Turku, Finland .,Åbo Akademi University, Turku, Finland.,Department of Pathology, University of Turku, Turku, Finland
| |
Collapse
|
36
|
Metformin inhibits JAK2V617F activity in MPN cells by activating AMPK and PP2A complexes containing the B56α subunit. Exp Hematol 2016; 44:1156-1165.e4. [PMID: 27576133 DOI: 10.1016/j.exphem.2016.08.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Revised: 08/16/2016] [Accepted: 08/18/2016] [Indexed: 12/18/2022]
Abstract
Metformin suppresses the growth of a variety of malignant hematologic cells. It is widely accepted that metformin inhibits the growth of malignant cells primarily by suppressing the mTOR pathway or regulating autophagy. In contrast, we found another possible mechanism that inhibits the growth of malignant cells, suppression of the activity of the oncogenic kinase JAK2V617F. We identified at least two distinct mechanisms involved in metformin-induced JAK2V617F inhibition. First, metformin increases reactive oxygen species levels in these cells, leading to the inhibition of SHP-2, a positive regulator of JAK2V617F. These effects of metformin require AMPK. Second, metformin activates protein tyrosine phosphatase PP2A, a negative regulator of JAK2V617F. Furthermore, we determined that among the numerous PP2A subfamily members, the PP2A complex containing the B56α subunit is responsible for the inhibition of JAK2V617F. In contrast, the B56α-containing PP2A complex functions as a positive regulator of JAK2V617F by inhibiting AMPK. Finally, we determined that metformin enhances the antileukemic action of ruxolitinib in HEL and SET-2 cells. Our present observations suggest that the combination of metformin with ruxolitinib might be a new therapeutic option for treating JAK2V617F-induced myeloproliferative neoplasms. In addition, activators specific for PP2A complexes containing the B56α subunit may be useful for the treatment of JAK2V617F-induced myeloproliferative neoplasms.
Collapse
|
37
|
Jiang Z, Lao T, Qiu W, Polverino F, Gupta K, Guo F, Mancini JD, Naing ZZC, Cho MH, Castaldi PJ, Sun Y, Yu J, Laucho-Contreras ME, Kobzik L, Raby BA, Choi AMK, Perrella MA, Owen CA, Silverman EK, Zhou X. A Chronic Obstructive Pulmonary Disease Susceptibility Gene, FAM13A, Regulates Protein Stability of β-Catenin. Am J Respir Crit Care Med 2016; 194:185-97. [PMID: 26862784 PMCID: PMC5003213 DOI: 10.1164/rccm.201505-0999oc] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Accepted: 01/21/2016] [Indexed: 12/28/2022] Open
Abstract
RATIONALE A genetic locus within the FAM13A gene has been consistently associated with chronic obstructive pulmonary disease (COPD) in genome-wide association studies. However, the mechanisms by which FAM13A contributes to COPD susceptibility are unknown. OBJECTIVES To determine the biologic function of FAM13A in human COPD and murine COPD models and discover the molecular mechanism by which FAM13A influences COPD susceptibility. METHODS Fam13a null mice (Fam13a(-/-)) were generated and exposed to cigarette smoke. The lung inflammatory response and airspace size were assessed in Fam13a(-/-) and Fam13a(+/+) littermate control mice. Cellular localization of FAM13A protein and mRNA levels of FAM13A in COPD lungs were assessed using immunofluorescence, Western blotting, and reverse transcriptase-polymerase chain reaction, respectively. Immunoprecipitation followed by mass spectrometry identified cellular proteins that interact with FAM13A to reveal insights on FAM13A's function. MEASUREMENTS AND MAIN RESULTS In murine and human lungs, FAM13A is expressed in airway and alveolar type II epithelial cells and macrophages. Fam13a null mice (Fam13a(-/-)) were resistant to chronic cigarette smoke-induced emphysema compared with Fam13a(+/+) mice. In vitro, FAM13A interacts with protein phosphatase 2A and recruits protein phosphatase 2A with glycogen synthase kinase 3β and β-catenin, inducing β-catenin degradation. Fam13a(-/-) mice were also resistant to elastase-induced emphysema, and this resistance was reversed by coadministration of a β-catenin inhibitor, suggesting that FAM13A could increase the susceptibility of mice to emphysema development by inhibiting β-catenin signaling. Moreover, human COPD lungs had decreased protein levels of β-catenin and increased protein levels of FAM13A. CONCLUSIONS We show that FAM13A may influence COPD susceptibility by promoting β-catenin degradation.
Collapse
Affiliation(s)
- Zhiqiang Jiang
- Channing Division of Network Medicine, Department of Medicine
| | - Taotao Lao
- Channing Division of Network Medicine, Department of Medicine
| | - Weiliang Qiu
- Channing Division of Network Medicine, Department of Medicine
| | - Francesca Polverino
- Division of Pulmonary and Critical Care Medicine, Department of Medicine
- The Lovelace Respiratory Research Institute, Albuquerque, New Mexico
| | - Kushagra Gupta
- Division of Pulmonary and Critical Care Medicine, Department of Medicine
| | - Feng Guo
- Channing Division of Network Medicine, Department of Medicine
| | - John D. Mancini
- Channing Division of Network Medicine, Department of Medicine
| | | | - Michael H. Cho
- Channing Division of Network Medicine, Department of Medicine
- Division of Pulmonary and Critical Care Medicine, Department of Medicine
| | - Peter J. Castaldi
- Channing Division of Network Medicine, Department of Medicine
- Division of General Internal Medicine, Department of Medicine, and
| | - Yang Sun
- Division of Pulmonary and Critical Care Medicine, Department of Medicine
| | - Jane Yu
- Division of Pulmonary and Critical Care Medicine, Department of Medicine
| | | | - Lester Kobzik
- Department of Pathology, Brigham and Women’s Hospital, Boston, Massachusetts; and
| | - Benjamin A. Raby
- Channing Division of Network Medicine, Department of Medicine
- Division of Pulmonary and Critical Care Medicine, Department of Medicine
| | | | - Mark A. Perrella
- Division of Pulmonary and Critical Care Medicine, Department of Medicine
- Pediatric Newborn Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts
| | - Caroline A. Owen
- Division of Pulmonary and Critical Care Medicine, Department of Medicine
- The Lovelace Respiratory Research Institute, Albuquerque, New Mexico
| | - Edwin K. Silverman
- Channing Division of Network Medicine, Department of Medicine
- Division of Pulmonary and Critical Care Medicine, Department of Medicine
| | - Xiaobo Zhou
- Channing Division of Network Medicine, Department of Medicine
- Division of Pulmonary and Critical Care Medicine, Department of Medicine
| |
Collapse
|
38
|
Liu H, Gu Y, Wang H, Yin J, Zheng G, Zhang Z, Lu M, Wang C, He Z. Overexpression of PP2A inhibitor SET oncoprotein is associated with tumor progression and poor prognosis in human non-small cell lung cancer. Oncotarget 2016; 6:14913-25. [PMID: 25945834 PMCID: PMC4558125 DOI: 10.18632/oncotarget.3818] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 03/29/2015] [Indexed: 01/09/2023] Open
Abstract
SET oncoprotein is an endogenous inhibitor of protein phosphatase 2A (PP2A), and SET-mediated PP2A inhibition is an important regulatory mechanism for promoting cancer initiation and progression of several types of human leukemia disease. However, its potential relevance in solid tumors as non-small cell lung cancer (NSCLC) remains mostly unknown. In this study, we showed that SET was evidently overexpressed in human NSCLC cell lines and NSCLC tissues. Clinicopathologic analysis showed that SET expression was significantly correlated with clinical stage (p < 0.001), and lymph node metastasis (p < 0.05). Kaplan-Meier analysis revealed that patients with high SET expression had poorer overall survival rates than those with low SET expression. Moreover, knockdown of SET in NSCLC cells resulted in attenuated proliferative and invasive abilities. The biological effect of SET on proliferation and invasion was mediated by the inhibition of the PP2A, which in turn, activation of AKT and ERK, increased the expression of cyclin D1 and MMP9, and decreased the expression of p27. Furthermore, we observed that restoration of PP2A using SET antagonist FTY720 impaired proliferative and invasive potential in vitro, as well as inhibited tumor growth in vivo of NSCLC cells. Taken together, SET oncoprotein plays an important role in NSCLC progression, which could serve as a potential prognosis marker and a novel therapeutic target for NSCLC patients.
Collapse
Affiliation(s)
- Hao Liu
- Cancer Hospital and Cancer Research Institute, Guangzhou Medical University, Guangzhou, PR China
| | - Yixue Gu
- Cancer Hospital and Cancer Research Institute, Guangzhou Medical University, Guangzhou, PR China
| | - Hongsheng Wang
- Department of Microbial and Biochemical Pharmacy, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, PR China
| | - Jiang Yin
- Cancer Hospital and Cancer Research Institute, Guangzhou Medical University, Guangzhou, PR China
| | - Guopei Zheng
- Cancer Hospital and Cancer Research Institute, Guangzhou Medical University, Guangzhou, PR China
| | - Zhijie Zhang
- Cancer Hospital and Cancer Research Institute, Guangzhou Medical University, Guangzhou, PR China
| | - Minyin Lu
- Cancer Hospital and Cancer Research Institute, Guangzhou Medical University, Guangzhou, PR China
| | - Chenkun Wang
- Cancer Hospital and Cancer Research Institute, Guangzhou Medical University, Guangzhou, PR China
| | - Zhimin He
- Cancer Hospital and Cancer Research Institute, Guangzhou Medical University, Guangzhou, PR China
| |
Collapse
|
39
|
Pusey M, Bail S, Xu Y, Buiakova O, Nestor M, Yang JJ, Rice LM. Inhibition of protein methylesterase 1 decreased cancerous phenotypes in endometrial adenocarcinoma cell lines and xenograft tumor models. Tumour Biol 2016; 37:11835-11842. [PMID: 27048286 DOI: 10.1007/s13277-016-5036-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 03/28/2016] [Indexed: 12/15/2022] Open
Abstract
Protein methylesterase 1 (PME-1) promotes cancerous phenotypes through the demethylation and inactivation of protein phosphatase 2A. We previously demonstrated that PME-1 overexpression promotes Akt, ERK, and may promote Wnt signaling and increases tumor burden in a xenograft model of endometrial cancer. Here, we show that covalent PME-1 inhibitors decrease cell proliferation and invasive growth in vitro but have no effect in vivo at the concentrations tested; however, depletion of PME-1 with shRNA in an endometrial cancer xenograft model significantly reduced tumor growth. Thus, discovery of more potent PME-1 inhibitors may be beneficial for the treatment of endometrial cancer.
Collapse
Affiliation(s)
- Michelle Pusey
- Oncoveda, Cancer Signaling and Cell Cycle Team, Medical Diagnostic Laboratories, LLC, 1000 Waterview Drive, Room 345, Hamilton, NJ, 08691, USA
| | - Sophie Bail
- Oncoveda, Cancer Signaling and Cell Cycle Team, Medical Diagnostic Laboratories, LLC, 1000 Waterview Drive, Room 345, Hamilton, NJ, 08691, USA
| | - Yan Xu
- Invivotek, LLC, 16 Black Forest Road, Hamilton, NJ, 08691, USA
| | - Olesia Buiakova
- Invivotek, LLC, 16 Black Forest Road, Hamilton, NJ, 08691, USA
| | - Mariya Nestor
- Pathology Department, Members of Genesis Biotechnology Group, LLC, Medical Diagnostic Laboratories LLC, 2439 Kuser Road, Hamilton, NJ, 08690, USA
| | - Jing-Jing Yang
- Pathology Department, Members of Genesis Biotechnology Group, LLC, Medical Diagnostic Laboratories LLC, 2439 Kuser Road, Hamilton, NJ, 08690, USA
| | - Lyndi M Rice
- Oncoveda, Cancer Signaling and Cell Cycle Team, Medical Diagnostic Laboratories, LLC, 1000 Waterview Drive, Room 345, Hamilton, NJ, 08691, USA.
| |
Collapse
|
40
|
LI YUNWEI, YU DONGYANG, SHENG WEIWEI, SONG HE, LI YUJI, DONG MING. Co-expression of FOXL1 and PP2A inhibits proliferation inducing apoptosis in pancreatic cancer cells via promoting TRAIL and reducing phosphorylated MYC. Oncol Rep 2016; 35:2198-206. [DOI: 10.3892/or.2016.4592] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 09/17/2015] [Indexed: 11/05/2022] Open
|
41
|
Liu J, Wang H, Wang B, Chen T, Wang X, Huang P, Xu L, Guo Z. Microcystin-LR promotes proliferation by activating Akt/S6K1 pathway and disordering apoptosis and cell cycle associated proteins phosphorylation in HL7702 cells. Toxicol Lett 2016; 240:214-25. [DOI: 10.1016/j.toxlet.2015.10.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 09/30/2015] [Accepted: 10/17/2015] [Indexed: 12/14/2022]
|
42
|
Nagy Z, Baghy K, Hunyadi-Gulyás É, Micsik T, Nyírő G, Rácz G, Butz H, Perge P, Kovalszky I, Medzihradszky KF, Rácz K, Patócs A, Igaz P. Evaluation of 9-cis retinoic acid and mitotane as antitumoral agents in an adrenocortical xenograft model. Am J Cancer Res 2015; 5:3645-3658. [PMID: 26885453 PMCID: PMC4731638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Accepted: 11/07/2015] [Indexed: 06/05/2023] Open
Abstract
The available drug treatment options for adrenocortical carcinoma (ACC) are limited. In our previous studies, the in vitro activity of 9-cis retinoic acid (9-cisRA) on adrenocortical NCI-H295R cells was shown along with its antitumoral effects in a small pilot xenograft study. Our aim was to dissect the antitumoral effects of 9-cisRA on ACC in a large-scale xenograft study involving mitotane, 9-cisRA and their combination. 43 male SCID mice inoculated with NCI-H295R cells were treated in four groups (i. control, ii. 9-cisRA, iii. mitotane, iv. 9-cisRA + mitotane) for 28 days. Tumor size follow-up, histological and immunohistochemical (Ki-67) analysis, tissue gene expression microarray, quantitative real-time-PCR for the validation of microarray results and to detect circulating microRNAs were performed. Protein expression was studied by proteomics and Western-blot validation. Only mitotane alone and the combination of 9-cisRA and mitotane resulted in significant tumor size reduction. The Ki-67 index was significantly reduced in both 9-cisRA and 9-cisRA+mitotane groups. Only modest changes at the mRNA level were found: the 9-cisRA-induced overexpression of apolipoprotein A4 and down-regulation of phosphodiesterase 4A was validated. The expression of circulating hsa-miR-483-5p was significantly reduced in the combined treatment group. The SET protein was validated as being significantly down-regulated in the combined mitotane+9-cisRA group. 9-cisRA might be a helpful additive agent in the treatment of ACC in combination with mitotane. Circulating hsa-miR-483-5p could be utilized for monitoring the treatment efficacy in ACC patients, and the treatment-induced reduction in protein SET expression might raise its relevance in ACC biology.
Collapse
Affiliation(s)
- Zoltán Nagy
- The 2 Department of Medicine, Faculty of Medicine, Semmelweis UniversityH-1088 Budapest, Szentkirályi Str. 46., Hungary
| | - Kornélia Baghy
- The 1 Department of Pathology and Experimental Cancer Research, Faculty of Medicine, Semmelweis UniversityH-1088 Budapest, Üllői Str. 26., Hungary
| | - Éva Hunyadi-Gulyás
- Laboratory of Proteomics, Biological Research CentreH-6726 Szeged, Temesvári Krt. 62., Hungary
| | - Tamás Micsik
- The 1 Department of Pathology and Experimental Cancer Research, Faculty of Medicine, Semmelweis UniversityH-1088 Budapest, Üllői Str. 26., Hungary
| | - Gábor Nyírő
- Molecular Medicine Research Group, Hungarian Academy of Sciences and Semmelweis UniversitySzentkirályi Str. 46., H-1088 Budapest, Hungary
| | - Gergely Rácz
- The 1 Department of Pathology and Experimental Cancer Research, Faculty of Medicine, Semmelweis UniversityH-1088 Budapest, Üllői Str. 26., Hungary
| | - Henriett Butz
- Molecular Medicine Research Group, Hungarian Academy of Sciences and Semmelweis UniversitySzentkirályi Str. 46., H-1088 Budapest, Hungary
| | - Pál Perge
- The 2 Department of Medicine, Faculty of Medicine, Semmelweis UniversityH-1088 Budapest, Szentkirályi Str. 46., Hungary
| | - Ilona Kovalszky
- The 1 Department of Pathology and Experimental Cancer Research, Faculty of Medicine, Semmelweis UniversityH-1088 Budapest, Üllői Str. 26., Hungary
| | - Katalin F Medzihradszky
- Laboratory of Proteomics, Biological Research CentreH-6726 Szeged, Temesvári Krt. 62., Hungary
| | - Károly Rácz
- The 2 Department of Medicine, Faculty of Medicine, Semmelweis UniversityH-1088 Budapest, Szentkirályi Str. 46., Hungary
- Molecular Medicine Research Group, Hungarian Academy of Sciences and Semmelweis UniversitySzentkirályi Str. 46., H-1088 Budapest, Hungary
| | - Attila Patócs
- Molecular Medicine Research Group, Hungarian Academy of Sciences and Semmelweis UniversitySzentkirályi Str. 46., H-1088 Budapest, Hungary
- “Lendület-2013” Research Group, Hungarian Academy of Sciences and Semmelweis UniversitySzentkirályi Str. 46., H-1088 Budapest, Hungary
| | - Peter Igaz
- The 2 Department of Medicine, Faculty of Medicine, Semmelweis UniversityH-1088 Budapest, Szentkirályi Str. 46., Hungary
| |
Collapse
|
43
|
Yu C, Ji SY, Sha QQ, Sun QY, Fan HY. CRL4-DCAF1 ubiquitin E3 ligase directs protein phosphatase 2A degradation to control oocyte meiotic maturation. Nat Commun 2015; 6:8017. [PMID: 26281983 PMCID: PMC4557334 DOI: 10.1038/ncomms9017] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 07/07/2015] [Indexed: 01/10/2023] Open
Abstract
Oocyte meiosis is a specialized cell cycle that gives rise to fertilizable haploid gametes and is precisely controlled in various dimensions. We recently found that E3 ubiquitin ligase CRL4 is required for female fertility by regulating DNA hydroxymethylation to maintain oocyte survival and to promote zygotic genome reprogramming. However, not all phenotypes of CRL4-deleted oocytes could be explained by this mechanism. Here we show that CRL4 controls oocyte meiotic maturation by proteasomal degradation of protein phosphatase 2A scaffold subunit, PP2A-A. Oocyte-specific deletion of DDB1 or DCAF1 (also called VPRBP) results in delayed meiotic resumption and failure to complete meiosis I along with PP2A-A accumulation. DCAF1 directly binds to and results in the poly-ubiquitination of PP2A-A. Moreover, combined deletion of Ppp2r1a rescues the meiotic defects caused by DDB1/DCAF1 deficiency. These results provide in vivo evidence that CRL4-directed PP2A-A degradation is physiologically essential for regulating oocyte meiosis and female fertility. The E3 ubiquitin ligase CRL4 regulates oocyte survival through hydroxymethylation of genomic DNA. Here Yu et al. show that CRL4 is also required for oocytes to complete meiosis I by mediating the poly-ubiquitination and proteasomal degradation of the cell cycle regulator protein phosphatase 2A-A subunit.
Collapse
Affiliation(s)
- Chao Yu
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou 310058, China
| | - Shu-Yan Ji
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou 310058, China
| | - Qian-Qian Sha
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou 310058, China
| | - Qing-Yuan Sun
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Heng-Yu Fan
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou 310058, China
| |
Collapse
|
44
|
Ruvolo PP. The Interplay between PP2A and microRNAs in Leukemia. Front Oncol 2015; 5:43. [PMID: 25750899 PMCID: PMC4335100 DOI: 10.3389/fonc.2015.00043] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 02/05/2015] [Indexed: 12/19/2022] Open
Abstract
Protein phosphatase 2A (PP2A) is a serine/threonine phosphatase family whose members have been implicated in tumor suppression in many cancer models. In many cancers, loss of PP2A activity has been associated with tumorigenesis and drug resistance. Loss of PP2A results in failure to turn off survival signaling cascades that drive drug resistance such as those regulated by protein kinase B. PP2A is responsible for modulating function and controlling expression of tumor suppressors such as p53 and oncogenes such as BCL2 and MYC. Thus, PP2A has diverse functions regulating cell survival. The importance of microRNAs (miRs) is emerging in cancer biology. A role for miR regulation of PP2A is not well understood; however, recent studies suggest a number of clinically significant miRs such as miR-155 and miR-19 may include PP2A targets. We have recently found that a PP2A B subunit (B55α) can regulate a number of miRs in acute myeloid leukemia cells. The identification of a miR/PP2A axis represents a novel regulatory pathway in cellular homeostasis. The ability of miRs to suppress specific PP2A targets and for PP2A to control such miRs can add an extra level of control in signaling that could be used as a rheostat for many signaling cascades that maintain cellular homeostasis. As such, loss of PP2A or expression of miRs relevant for PP2A function could promote tumorigenesis or at least result in drug resistance. In this review, we will cover the current state of miR regulation of PP2A with a focus on leukemia. We will also briefly discuss what is known of PP2A regulation of miR expression.
Collapse
Affiliation(s)
- Peter P Ruvolo
- Department of Leukemia, University of Texas MD Anderson Cancer Center , Houston, TX , USA
| |
Collapse
|
45
|
Lee CW, Yang FC, Chang HY, Chou H, Tan BCM, Lee SC. Interaction between salt-inducible kinase 2 and protein phosphatase 2A regulates the activity of calcium/calmodulin-dependent protein kinase I and protein phosphatase methylesterase-1. J Biol Chem 2015; 289:21108-19. [PMID: 24841198 DOI: 10.1074/jbc.m113.540229] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Salt-inducible kinase 2 (SIK2) is the only AMP-activated kinase (AMPK) family member known to interact with protein phosphatase 2 (PP2A). However, the functional aspects of this complex are largely unknown. Here we report that the SIK2-PP2A complex preserves both kinase and phosphatase activities. In this capacity,SIK2 attenuates the association of the PP2A repressor, the protein phosphatase methylesterase-1 (PME-1), thus preserving the methylation status of the PP2A catalytic subunit. Furthermore, the SIK2-PP2A holoenzyme complex dephosphorylates and inactivates Ca2(+)/calmodulin-dependent protein kinase I (CaMKI), an upstream kinase for phosphorylating PME-1/Ser(15). The functionally antagonistic SIK2-PP2A and CaMKI and PME-1 networks thus constitute a negative feedback loop that modulates the phosphatase activity of PP2A. Depletion of SIK2 led to disruption of the SIK2-PP2A complex, activation of CaMKI, and downstream effects, including phosphorylation of HDAC5/Ser(259), sequestration of HDAC5 in the cytoplasm, and activation of myocyte-specific enhancer factor 2C (MEF2C)-mediated gene expression. These results suggest that the SIK2-PP2A complex functions in the regulation of MEF2C-dependent transcription. Furthermore, this study suggests that the tightly linked regulatory loop comprised of the SIK2-PP2A and CaMKI and PME-1 networks may function in fine-tuning cell proliferation and stress response.
Collapse
|
46
|
Khanna A, Pimanda JE. Clinical significance of cancerous inhibitor of protein phosphatase 2A in human cancers. Int J Cancer 2015; 138:525-32. [DOI: 10.1002/ijc.29431] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Revised: 12/28/2014] [Accepted: 12/29/2014] [Indexed: 01/03/2023]
Affiliation(s)
- Anchit Khanna
- Lowy Cancer Research Centre and Prince of Wales Clinical School, University of New South Wales (UNSW) Medicine Department; Sydney New South Wales 2052 Australia
| | - John E. Pimanda
- Lowy Cancer Research Centre and Prince of Wales Clinical School, University of New South Wales (UNSW) Medicine Department; Sydney New South Wales 2052 Australia
- Department of Haematology; the Prince of Wales Hospital; Randwick New South Wales Australia
| |
Collapse
|
47
|
Vogel WK, Gafken PR, Leid M, Filtz TM. Kinetic analysis of BCL11B multisite phosphorylation-dephosphorylation and coupled sumoylation in primary thymocytes by multiple reaction monitoring mass spectroscopy. J Proteome Res 2014; 13:5860-8. [PMID: 25423098 PMCID: PMC4261940 DOI: 10.1021/pr5007697] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Transcription factors with multiple post-translational modifications (PTMs) are not uncommon, but comprehensive information on site-specific dynamics and interdependence is comparatively rare. Assessing dynamic changes in the extent of PTMs has the potential to link multiple sites both to each other and to biological effects observable on the same time scale. The transcription factor and tumor suppressor BCL11B is critical to three checkpoints in T-cell development and is a target of a T-cell receptor-mediated MAP kinase signaling. Multiple reaction monitoring (MRM) mass spectroscopy was used to assess changes in relative phosphorylation on 18 of 23 serine and threonine residues and sumoylation on one of two lysine resides in BCL11B. We have resolved the composite phosphorylation-dephosphorylation and sumoylation changes of BCL11B in response to MAP kinase activation into a complex pattern of site-specific PTM changes in primary mouse thymocytes. The site-specific resolution afforded by MRM analyses revealed four kinetic patterns of phosphorylation and one of sumoylation, including both rapid simultaneous site-specific increases and decreases at putative MAP kinase proline-directed phosphorylation sites, following stimulation. These data additionally revealed a novel spatiotemporal bisphosphorylation motif consisting of two kinetically divergent proline-directed phosphorylation sites spaced five residues apart.
Collapse
Affiliation(s)
- Walter K Vogel
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University , Corvallis, Oregon 97331, United States
| | | | | | | |
Collapse
|
48
|
Gozdecka M, Lyons S, Kondo S, Taylor J, Li Y, Walczynski J, Thiel G, Breitwieser W, Jones N. JNK suppresses tumor formation via a gene-expression program mediated by ATF2. Cell Rep 2014; 9:1361-74. [PMID: 25456131 DOI: 10.1016/j.celrep.2014.10.043] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 07/16/2014] [Accepted: 10/14/2014] [Indexed: 02/09/2023] Open
Abstract
JNK and p38 phosphorylate a diverse set of substrates and, consequently, can act in a context-dependent manner to either promote or inhibit tumor growth. Elucidating the functions of specific substrates of JNK and p38 is therefore critical for our understanding of these kinases in cancer. ATF2 is a phosphorylation-dependent transcription factor and substrate of both JNK and p38. Here, we show ATF2 suppresses tumor formation in an orthotopic model of liver cancer and cellular transformation in vitro. Furthermore, we find that suppression of tumorigenesis by JNK requires ATF2. We identify a transcriptional program activated by JNK via ATF2 and provide examples of JNK- and ATF2-dependent genes that block cellular transformation. Significantly, we also show that ATF2-dependent gene expression is frequently downregulated in human cancers, indicating that amelioration of JNK-ATF2-mediated suppression may be a common event during tumor development.
Collapse
Affiliation(s)
- Malgorzata Gozdecka
- Department of Cell Regulation, CRUK Manchester Institute, Paterson Building, University of Manchester, Manchester M20 4BX, UK; Haematological Cancer Genetics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Stephen Lyons
- Department of Cell Regulation, CRUK Manchester Institute, Paterson Building, University of Manchester, Manchester M20 4BX, UK
| | - Saki Kondo
- Department of Cell Regulation, CRUK Manchester Institute, Paterson Building, University of Manchester, Manchester M20 4BX, UK; Laboratory of Molecular Genetics, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Janet Taylor
- Central Manchester NHS Trust and University of Manchester, the Nowgen Centre, 29 Grafton Street, Manchester M13 9WU, UK; Applied Computational Biology and Bioinformatics Group, CRUK Manchester Institute, Paterson Building, University of Manchester, Manchester M20 4BX, UK
| | - Yaoyong Li
- Applied Computational Biology and Bioinformatics Group, CRUK Manchester Institute, Paterson Building, University of Manchester, Manchester M20 4BX, UK
| | - Jacek Walczynski
- Department of Cell Regulation, CRUK Manchester Institute, Paterson Building, University of Manchester, Manchester M20 4BX, UK
| | - Gerald Thiel
- Department of Medical Biochemistry and Molecular Biology, University of Saarland Medical Center, Building 44, 66421 Homburg, Germany
| | - Wolfgang Breitwieser
- Department of Cell Regulation, CRUK Manchester Institute, Paterson Building, University of Manchester, Manchester M20 4BX, UK
| | - Nic Jones
- Department of Cell Regulation, CRUK Manchester Institute, Paterson Building, University of Manchester, Manchester M20 4BX, UK.
| |
Collapse
|
49
|
Inoue D, Kitaura J, Matsui H, Hou HA, Chou WC, Nagamachi A, Kawabata KC, Togami K, Nagase R, Horikawa S, Saika M, Micol JB, Hayashi Y, Harada Y, Harada H, Inaba T, Tien HF, Abdel-Wahab O, Kitamura T. SETBP1 mutations drive leukemic transformation in ASXL1-mutated MDS. Leukemia 2014; 29:847-57. [PMID: 25306901 PMCID: PMC4501574 DOI: 10.1038/leu.2014.301] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 09/22/2014] [Accepted: 10/02/2014] [Indexed: 02/06/2023]
Abstract
Mutations in ASXL1 are frequent in patients with myelodysplastic syndrome (MDS) and associated with adverse survival yet the molecular pathogenesis of ASXL1 mutations are not fully understood. Recently it has been found that deletion of Asxl1 or expression of C-terminal-truncating ASXL1 mutations (ASXL1-MT) inhibit myeloid differentiation and induce MDS-like disease in mice. Here, we find that SETBP1 mutations (SETBP1-MT) are enriched among patients with ASXL1-mutated MDS patients and associated with increased incidence of leukemic transformation as well as shorter survival, suggesting SETBP1-MT play a critical role in leukemic transformation of MDS. We identify that SETBP1-MT inhibit ubiquitination and subsequent degradation of SETBP1, resulting in increased expression. Expression of SETBP1-MT, in turn, inhibited Pp2a activity, leading to Akt activation and enhanced expression of posterior Hoxa genes in ASXL1 mutant cells. Biologically, SETBP1-MT augmented ASXL1-MT-induced differentiation block, inhibited apoptosis, and enhanced myeloid colony output. SETBP1-MT collaborated with ASXL1-MT in inducing AML in vivo. The combination of ASXL1-MT and SETBP1-MT activated a stem cell signature and repressed the TGF-β signaling pathway, in contrast to the ASXL1-MT-induced MDS model. These data reveal that SETBP1-MT are critical drivers of ASXL1-mutated MDS and identify several deregulated pathways as potential therapeutic targets in high-risk MDS.
Collapse
Affiliation(s)
- D Inoue
- Division of Cellular Therapy, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - J Kitaura
- Division of Cellular Therapy, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - H Matsui
- Department of Molecular Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan
| | - H-A Hou
- Division of Hematology, Department of Internal Medicine, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - W-C Chou
- Division of Hematology, Department of Internal Medicine, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - A Nagamachi
- Department of Molecular Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan
| | - K C Kawabata
- Division of Cellular Therapy, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - K Togami
- Division of Cellular Therapy, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - R Nagase
- Division of Cellular Therapy, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - S Horikawa
- Division of Cellular Therapy, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - M Saika
- Division of Cellular Therapy, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - J-B Micol
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Y Hayashi
- Division of Cellular Therapy, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Y Harada
- Department of Hematology, Juntendo University School of Medicine, Tokyo, Japan
| | - H Harada
- Department of Hematology, Juntendo University School of Medicine, Tokyo, Japan
| | - T Inaba
- Department of Molecular Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan
| | - H-F Tien
- Division of Hematology, Department of Internal Medicine, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - O Abdel-Wahab
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - T Kitamura
- Division of Cellular Therapy, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| |
Collapse
|
50
|
Nifoussi SK, Ratcliffe NR, Ornstein DL, Kasof G, Strack S, Craig RW. Inhibition of protein phosphatase 2A (PP2A) prevents Mcl-1 protein dephosphorylation at the Thr-163/Ser-159 phosphodegron, dramatically reducing expression in Mcl-1-amplified lymphoma cells. J Biol Chem 2014; 289:21950-9. [PMID: 24939844 DOI: 10.1074/jbc.m114.587873] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Abundant, sustained expression of prosurvival Mcl-1 is an important determinant of viability and drug resistance in cancer cells. The Mcl-1 protein contains PEST sequences (enriched in proline, glutamic acid, serine, and threonine) and is normally subject to rapid turnover via multiple different pathways. One of these pathways involves a phosphodegron in the PEST region, where Thr-163 phosphorylation primes for Ser-159 phosphorylation by glycogen synthase kinase-3. Turnover via this phosphodegron-targeted pathway is reduced in Mcl-1-overexpressing BL41-3 Burkitt lymphoma and other cancer cells; turnover is further slowed in the presence of phorbol ester-induced ERK activation, resulting in Mcl-1 stabilization and an exacerbation of chemoresistance. The present studies focused on Mcl-1 dephosphorylation, which was also found to profoundly influence turnover. Exposure of BL41-3 cells to an inhibitor of protein phosphatase 2A (PP2A), okadaic acid, resulted in a rapid increase in phosphorylation at Thr-163 and Ser-159, along with a precipitous decrease in Mcl-1 expression. The decline in Mcl-1 expression preceded the appearance of cell death markers and was not slowed in the presence of phorbol ester. Upon exposure to calyculin A, which also potently inhibits PP2A, versus tautomycin, which does not, only the former increased Thr-163/Ser-159 phosphorylation and decreased Mcl-1 expression. Mcl-1 co-immunoprecipitated with PP2A upon transfection into CHO cells, and PP2A/Aα knockdown recapitulated the increase in Mcl-1 phosphorylation and decrease in expression. In sum, inhibition of PP2A prevents Mcl-1 dephosphorylation and results in rapid loss of this prosurvival protein in chemoresistant cancer cells.
Collapse
Affiliation(s)
- Shanna K Nifoussi
- From the Departments of Pharmacology and Toxicology and the Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire 03766
| | - Nora R Ratcliffe
- Pathology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755, the Veterans Affairs Medical Center, White River Junction, Vermont 05001
| | - Deborah L Ornstein
- Pathology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755
| | - Gary Kasof
- Cell Signaling Technology, Danvers, Massachusetts 01923, and
| | - Stefan Strack
- Department of Pharmacology, The University of Iowa, Iowa City, Iowa 52242
| | - Ruth W Craig
- From the Departments of Pharmacology and Toxicology and the Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire 03766,
| |
Collapse
|