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Loss of protein phosphatase 2A regulatory subunit B56δ promotes spontaneous tumorigenesis in vivo

Abstract

Protein Phosphatase 2A (PP2A) enzymes counteract diverse kinase-driven oncogenic pathways and their function is frequently impaired in cancer. PP2A inhibition is indispensable for full transformation of human cells, but whether loss of PP2A is sufficient for tumorigenesis in vivo has remained elusive. Here, we describe spontaneous tumor development in knockout mice for Ppp2r5d, encoding the PP2A regulatory B56δ subunit. Several primary tumors were observed, most commonly, hematologic malignancies and hepatocellular carcinomas (HCCs). Targeted immunoblot and immunohistochemistry analysis of the HCCs revealed heterogeneous activation of diverse oncogenic pathways known to be suppressed by PP2A-B56. RNA sequencing analysis unveiled, however, a common role for oncogenic c-Myc activation in the HCCs, independently underscored by c-Myc Ser62 hyperphosphorylation. Upstream of c-Myc, GSK-3β Ser9 hyperphosphorylation occurred both in the HCCs and non-cancerous B56δ-null livers. Thus, uncontrolled c-Myc activity due to B56δ-driven GSK-3β inactivation is the likely tumor predisposing factor. Our data provide the first compelling mouse genetics evidence sustaining the tumor suppressive activity of a single PP2A holoenzyme, constituting the final missing incentive for full clinical development of PP2A as cancer biomarker and therapy target.

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References

  1. Janssens V, Goris J, Van Hoof C . PP2A: the expected tumor suppressor. Curr Opin Genet Dev 2005; 15: 34–41.

    Article  CAS  PubMed  Google Scholar 

  2. Hahn WC, Counter CM, Lundberg AS, Beijersbergen RL, Brooks MW, Weinberg RA . Creation of human tumour cells with defined genetic elements. Nature 1999; 400: 464–468.

    Article  CAS  PubMed  Google Scholar 

  3. Hahn WC, Dessain SK, Brooks MW, King JE, Elenbaas B, Sabatini DM et al. Enumeration of the simian virus 40 early region elements necessary for human cell transformation. Mol Cell Biol 2002; 22: 2111–2123.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  4. Chen W, Possemato R, Campbell KT, Plattner CA, Pallas DC, Hahn WC . Identification of specific PP2A complexes involved in human cell transformation. Cancer Cell 2004; 5: 127–136.

    Article  CAS  PubMed  Google Scholar 

  5. Sablina AA, Hector M, Colpaert N, Hahn WC . Identification of PP2A complexes and pathways involved in cell transformation. Cancer Res 2010; 70: 10474–10484.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  6. Chen W, Arroyo JD, Timmons JC, Possemato R, Hahn WC . Cancer-associated PP2A Aalpha subunits induce functional haploinsufficiency and tumorigenicity. Cancer Res 2005; 65: 8183–8192.

    Article  CAS  PubMed  Google Scholar 

  7. Jackson JB, Pallas DC . Circumventing cellular control of PP2A by methylation promotes transformation in an Akt-dependent manner. Neoplasia 2012; 14: 585–599.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  8. Yeh E, Cunningham M, Arnold H, Chasse D, Monteith T, Ivaldi G et al. A signaling pathway controlling c-myc degradation that impacts oncogenic transformation of human cells. Nat Cell Biol 2004; 6: 308–318.

    Article  CAS  PubMed  Google Scholar 

  9. Sablina AA, Chen W, Arroyo JD, Corral L, Hector M, Bulmer SE et al. The tumor suppressor PP2A Abeta regulates the RalA GTPase. Cell 2007; 129: 969–982.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  10. Miller JP, Yeh N, Hofstetter CP, Keskin D, Goldstein AS, Koff A . p27kip1 levels reflect a nexus of oncogenic signaling during cell transformation. J Biol Chem 2012; 287: 19775–19785.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. Perrotti D, Neviani P . Protein phosphatase 2A: a target for anticancer therapy. Lancet Oncol 2013; 14: e229–e238.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  12. Sangodkar J, Farrington CC, McClinch K, Galsky MD, Kastrinsky DB, Narla G . All roads lead to PP2A: exploiting the therapeutic potential of this phosphatase. FEBS J 2016; 283: 1004–1024.

    Article  CAS  PubMed  Google Scholar 

  13. Wang SS, Esplin ED, Li JL, Huang L, Gazdar A, Minna J et al. Alterations of the PPP2R1B gene in human lung and colon cancer. Science 1998; 282: 284–287.

    Article  CAS  PubMed  Google Scholar 

  14. Calin GA, di Iasio MG, Caprini E, Vorechovsky I, Natali PG, Sozzi G et al. Low frequency of alterations of the alpha (PPP2R1A) and beta (PPP2R1B) isoforms of the subunit A of the serine-threonine phosphatase 2A in human neoplasms. Oncogene 2000; 19: 1191–1195.

    Article  CAS  PubMed  Google Scholar 

  15. Shih IeM Wang TL . Mutation of PPP2R1A: a new clue in unveiling the pathogenesis of uterine serous carcinoma. J Pathol 2011; 224: 1–4.

    Article  PubMed  Google Scholar 

  16. Haesen D, Abbasi Asbagh L, Derua R, Hubert A, Schrauwen S, Hoorne Y et al. Recurrent PPP2R1A mutations in uterine cancer act through a dominant-negative mechanism to increase malignant cell growth. Cancer Res 2016; 76: 5719–5731.

    Article  CAS  PubMed  Google Scholar 

  17. Ruediger R, Ruiz J, Walter G . Human cancer-associated mutations in the Aα subunit of protein phosphatase 2A increase lung cancer incidence in Aα knock-in and knockout mice. Mol Cell Biol 2011; 31: 3832–3844.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  18. Cheng Y, Liu W, Kim ST, Sun J, Lu L, Sun J et al. Evaluation of PPP2R2A as a prostate cancer susceptibility gene: a comprehensive germline and somatic study. Cancer Genet 2011; 204: 375–381.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  19. Nobumori Y, Shouse GP, Wu Y, Lee KJ, Shen B, Liu X . B56γ tumor-associated mutations provide new mechanisms for B56γ-PP2A tumor suppressor activity. Mol Cancer Res 2013; 11: 995–1003.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Curtis C, Shah SP, Chin SF, Turashvili G, Rueda OM, Dunning MJ et al. The genomic and transcriptomic architecture of 2,000 breast tumours reveals novel subgroups. Nature 2012; 486: 346–352.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Bluemn EG, Spencer ES, Mecham B, Gordon RR, Coleman I, Lewinshtein D et al. PPP2R2C loss promotes castration-resistance and is associated with increased prostate cancer-specific mortality. Mol Cancer Res 2013; 11: 568–578.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  22. Cristobal I, Cirauqui C, Castello-Cros R, Garcia-Orti L, Calasanz MJ, Odero MD . Downregulation of PPP2R5E is a common event in acute myeloid leukemia that affects the oncogenic potential of leukemic cells. Haematologica 2013; 98: e103–e104.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  23. Arriazu E, Pippa R, Odero MD . Protein phosphatase 2A as a therapeutic target in acute myeloid leukemia. Front Oncol 2016; 6: 78.

    Article  PubMed  PubMed Central  Google Scholar 

  24. Khanna A, Pimanda JA, Westermarck J . Cancerous inhibitor of protein phosphatase 2A, an emerging human oncoprotein and a potential cancer therapy target. Cancer Res 2013; 73: 6548–6553.

    Article  CAS  PubMed  Google Scholar 

  25. Chen LP, Lai YD, Li DC, Zhu XN, Yang P, Li WX et al. α4 is highly expressed in carcinogen-transformed human cells and primary human cancers. Oncogene 2011; 30: 2943–2953.

    Article  CAS  PubMed  Google Scholar 

  26. Puustinen P, Junttila MR, Vanhatupa S, Sablina AA, Hector ME, Teittinen K et al. PME-1 protects extracellular signal-regulated kinase pathway activity from protein phosphatase 2A-mediated inactivation in human malignant glioma. Cancer Res 2009; 69: 2870–2877.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  27. Wandzioch E, Pusey M, Werda A, Bail S, Bhaskar A, Nestor M et al. PME-1 modulates protein phosphatase 2A activity to promote the malignant phenotype of endometrial cancer cells. Cancer Res 2014; 74: 4295–4305.

    Article  CAS  PubMed  Google Scholar 

  28. Olive KP, Tuveson DA, Ruhe ZC, Yin B, Willis NA, Bronson RT et al. Mutant p53 gain of function in two mouse models of Li-Fraumeni syndrome. Cell 2004; 119: 847–860.

    Article  CAS  PubMed  Google Scholar 

  29. Lang GA, Iwakuma T, Suh YA, Liu G, Rao VA, Parant JM et al. Gain of function of a p53 hot spot mutation in a mouse model of Li-Fraumeni syndrome. Cell 2004; 119: 861–872.

    Article  CAS  PubMed  Google Scholar 

  30. Hu N, Gutsmann A, Herbert DC, Bradley A, Lee WH, Lee EY . Heterozygous Rb-1 delta 20/+mice are predisposed to tumors of the pituitary gland with a nearly complete penetrance. Oncogene 1994; 9: 1021–1027.

    CAS  PubMed  Google Scholar 

  31. Louis JV, Martens E, Borghgraef P, Lambrecht C, Sents W, Longin S et al. Mice lacking phosphatase PP2A subunit PR61/B'delta (Ppp2r5d) develop spatially restricted tauopathy by deregulation of CDK5 and GSK3beta. Proc Natl Acad Sci U S A 2011; 108: 6957–6962.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  32. Ward JM . Lymphomas and leukemias in mice. Exp Toxicol Pathol 2006; 57: 377–381.

    Article  PubMed  Google Scholar 

  33. Singal AG, El-Serag HB . Hepatocellular carcinoma from epidemiology to prevention: translating knowledge into practice. Clin Gastroenterol Hepatol 2015; 13: 2140–2151.

    Article  PubMed  PubMed Central  Google Scholar 

  34. Seeling JM, Miller JR, Gil R, Moon RT, White R, Virshup DM . Regulation of beta-catenin signaling by the B56 subunit of protein phosphatase 2A. Science 1999; 283: 2089–2091.

    Article  CAS  PubMed  Google Scholar 

  35. Letourneux C, Rocher G, Porteu F . B56-containing PP2A dephosphorylate ERK and their activity is controlled by the early gene IEX-1 and ERK. EMBO J 2006; 25: 727–738.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  36. Hahn K, Miranda M, Francis VA, Vendrell J, Zorzano A, Teleman AA . PP2A regulatory subunit PP2A-B' counteracts S6K phosphorylation. Cell Metab 2010; 11: 438–444.

    Article  CAS  PubMed  Google Scholar 

  37. Pinyol R, Nault JC, Quetglas IM, Zucman-Rossi J, Llovet JM . Molecular profiling of liver tumors: classification and clinical translation for decision making. Semin Liver Dis 2014; 34: 363–375.

    Article  CAS  PubMed  Google Scholar 

  38. Cadoret A, Ovejero C, Terris B, Souil E, Levy L, Lamers WH et al. New targets of beta-catenin signaling in the liver are involved in the glutamine metabolism. Oncogene 2002; 21: 8293–8301.

    Article  CAS  PubMed  Google Scholar 

  39. Janky R, Verfaillie A, Imrichová H, Van de Sande B, Standaert L, Christiaens V et al. iRegulon: from a gene list to a gene regulatory network using large motif and track collections. PLoS Comput Biol 2014; 10: e1003731.

    Article  PubMed  PubMed Central  Google Scholar 

  40. Hydbring P, Bahram F, Su Y, Tronnersjö S, Högstrand K, von der Lehr N et al. Phosphorylation by Cdk2 is required for Myc to repress Ras-induced senescence in cotransformation. Proc Natl Acad Sci USA 2010; 107: 58–63.

    Article  CAS  PubMed  Google Scholar 

  41. Khanna A, Böckelman C, Hemmes A, Junttila MR, Wiksten JP, Lundin M et al. MYC-dependent regulation and prognostic role of CIP2A in gastric cancer. J Natl Cancer Inst 2009; 101: 793–805.

    Article  CAS  PubMed  Google Scholar 

  42. Shachaf CM, Kopelman AM, Arvanitis C, Karlsson A, Beer S, Mandl S et al. MYC inactivation uncovers pluripotent differentiation and tumour dormancy in hepatocellular cancer. Nature 2004; 431: 1112–1117.

    Article  CAS  PubMed  Google Scholar 

  43. Kaposi-Novak P, Libbrecht L, Woo HG, Lee YH, Sears NC, Coulouarn C et al. Central role of c-Myc during malignant conversion in human hepatocarcinogenesis. Cancer Res 2009; 69: 2775–2782.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  44. Liu L, Eisenman RN . Regulation of c-Myc protein abundance by a protein phosphatase 2A-glycogen synthase kinase 3β-negative feedback pathway. Genes Cancer 2012; 3: 23–36.

    Article  PubMed  PubMed Central  Google Scholar 

  45. Arnold HK, Sears RC . Protein phosphatase 2A regulatory subunit B56alpha associates with c-myc and negatively regulates c-myc accumulation. Mol Cell Biol 2006; 26: 2832–2844.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  46. He TC, Sparks AB, Rago C, Hermeking H, Zawel L, da Costa LT et al. Identification of c-MYC as a target of the APC pathway. Science 1998; 281: 1509–1512.

    Article  CAS  PubMed  Google Scholar 

  47. Shouse GP, Nobumori Y, Liu X . A B56gamma mutation in lung cancer disrupts the p53-dependent tumor-suppressor function of protein phosphatase 2A. Oncogene 2010; 29: 3933–3941.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  48. Lai TY, Yen CJ, Tsai HW, Yang YS, Hong WF, Chiang CW . The B56γ3 regulatory subunit-containing protein phosphatase 2A outcompetes Akt to regulate p27KIP1 subcellular localization by selectively dephosphorylating phospho-Thr157 of p27KIP1. Oncotarget 2016; 7: 4542–4558.

    PubMed  Google Scholar 

  49. Varadkar P, Despres D, Kraman M, Lozier J, Phadke A, Nagaraju K et al. The protein phosphatase 2A B56γ regulatory subunit is required for heart development. Dev Dyn 2014; 243: 778–790.

    Article  CAS  PubMed  Google Scholar 

  50. Cheng YS, Seibert O, Klöting N, Dietrich A, Straßburger K, Fernández-Veledo S et al. PPP2R5C Couples Hepatic Glucose and Lipid Homeostasis. PLoS Genet 2015; 11: e1005561.

    Article  PubMed  PubMed Central  Google Scholar 

  51. Sents W, Meeusen B, Kalev P, Radaelli E, Sagaert X, Miermans E et alPP2A inactivation triggered by PPP2R4 haploinsufficiency promotes cancer development.

  52. Low IC, Loh T, Huang Y, Virshup DM, Pervaiz S . Ser70 phosphorylation of Bcl-2 by selective tyrosine nitration of PP2A-B56δ stabilizes its antiapoptotic activity. Blood 2014; 124: 2223–2234.

    Article  CAS  PubMed  Google Scholar 

  53. Hung MH, Chen YL, Chu PY, Shih CT, Yu HC, Tai WT et al. Upregulation of the oncoprotein SET determines poor clinical outcomes in hepatocellular carcinoma and shows therapeutic potential. Oncogene 2016; 35: 4891–4902.

    Article  CAS  PubMed  Google Scholar 

  54. He H, Wu G, Li W, Cao Y, Liu Y . CIP2A is highly expressed in hepatocellular carcinoma and predicts poor prognosis. Diagn Mol Pathol 2012; 21: 143–149.

    Article  CAS  PubMed  Google Scholar 

  55. Janghorban M, Farrell AS, Allen-Petersen BL, Pelz C, Daniel CJ, Oddo J et al. Targeting c-MYC by antagonizing PP2A inhibitors in breast cancer. Proc Natl Acad Sci USA 2014; 111: 9157–9162.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  56. Junttila MR, Puustinen P, Niemelä M, Ahola R, Arnold H, Böttzauw T et al. CIP2A inhibits PP2A in human malignancies. Cell 2007; 130: 51–62.

    Article  CAS  PubMed  Google Scholar 

  57. Leder A, Pattengale PK, Kuo A, Stewart TA, Leder P . Consequences of widespread deregulation of the c-myc gene in transgenic mice: multiple neoplasms and normal development. Cell 1986; 45: 485–495.

    Article  CAS  PubMed  Google Scholar 

  58. Martin M . Cutadapt removes adapter sequences from high-throughput sequencing reads. EMBnet.Journal 2011; 17: 10–12.

    Article  Google Scholar 

  59. Trapnell C, Pachter L, Salzberg SL . TopHat: discovering splice junctions with RNA-Seq. Bioinformatics 2009; 25: 1105–1111.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  60. Li H, Handsaker B, Wysoker A, Fennell T, Ruan J, Homer N et al. The Sequence Alignment/Map format and SAMtools. Bioinformatics 2009; 25: 2078–2079.

    Article  PubMed  PubMed Central  Google Scholar 

  61. Trapnell C, Williams BA, Pertea G, Mortazavi A, Kwan G, van Baren MJ et al. Transcript assembly and quantification by RNA-Seq reveals unannotated transcripts and isoform switching during cell differentiation. Nat Biotechnol 2010; 28: 511–515.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  62. Quinlan AR, Hall IM . BEDTools: a flexible suite of utilities for comparing genomic features. Bioinformatics 2010; 26: 841–842.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  63. Robinson MD, McCarthy DJ, Smyth GK . EdgeR: a Bioconductor package for differential expression analysis of digital gene expression data. Bioinformatics 2010; 26: 139–140.

    Article  CAS  PubMed  Google Scholar 

  64. Martens E, Stevens I, Janssens V, Vermeesch J, Götz J, Goris J et al. Genomic organisation, chromosomal localisation tissue distribution and developmental regulation of the PR61/B' regulatory subunits of protein phosphatase 2A in mice. J Mol Biol 2004; 336: 971–986.

    Article  CAS  PubMed  Google Scholar 

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Acknowledgements

We thank Y El-Aalamat (KU Leuven, ESAT) for help with statistical analysis, and P Vermaelen (KU Leuven, MOSAIC) for PET-scan analysis. Funding was provided by KU Leuven Research Fund (GOA/08/016 to VJ; OT/13/094 to VJ and AS), Research Foundation-Flanders (G.0582.11 to VJ; G.0B01.16N to VJ), Belgian IAP program (P7/13 to VJ), Flemish Agency for Innovation by Science and Technology (to CL) and the Flemish Cancer League (Emmanuel van der Schueren fellowship to WS).

Author contributions

CL performed all mouse-related and immunoblot experiments, analyzed the data and prepared manuscript figures. WS and JVL assisted CL in several mouse-related experiments (dissections, genotyping). LL, XS and PP performed histopathologic analyses. YH and JC performed RNAseq sample preparation and data analysis (IPA, iRegulon). AS analyzed data, co-supervised the study and revised the manuscript. VJ analyzed the data, supervised the study and wrote the manuscript.

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Correspondence to V Janssens.

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Lambrecht, C., Libbrecht, L., Sagaert, X. et al. Loss of protein phosphatase 2A regulatory subunit B56δ promotes spontaneous tumorigenesis in vivo. Oncogene 37, 544–552 (2018). https://doi.org/10.1038/onc.2017.350

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