Abstract
Background:
Fibrolamellar hepatocellular carcinoma (FL-HCC) affects children without underlying liver disease. A consistent mutation in FL-HCCs leads to fusion of the genes encoding a heat shock protein (DNAJB1) and the catalytic subunit of protein kinase A (PRKACA). We sought to characterize the resultant chimeric protein and its effects in FL-HCC.
Methods:
The expression pattern and subcellular localization of protein kinase A (PKA) subunits in FL-HCCs were compared to paired normal livers by quantitative polymerase chain reaction (qPCR), immunoblotting, and immunofluorescence. PKA activity was measured by radioactive kinase assay, and we determined whether the FL-HCC mutation is present in other primary liver tumors.
Results:
The fusion transcript and chimeric protein were detected exclusively in FL-HCCs. DNAJB1-PRKACA was expressed 10-fold higher than the wild-type PRKACA transcript, resulting in overexpression of the mutant protein in tumors. Consequently, FL-HCCs possess elevated cAMP-stimulated PKA activity compared to normal livers, despite similar Kms between the mutant and wild-type kinases.
Conclusion:
FL-HCCs in children and young adults uniquely overexpress DNAJB1-PRKACA, which results in elevated cAMP-dependent PKA activity. These data suggest that aberrant PKA signaling contributes to liver tumorigenesis.
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References
Nordenstedt H, White DL, El-Serag HB. The changing pattern of epidemiology in hepatocellular carcinoma. Dig Liver Dis 2010;42 Suppl 3:S206–14.
Hoshida Y. Molecular signatures and prognosis of hepatocellular carcinoma. Minerva Gastroenterol Dietol 2011;57:311–22.
Kan Z, Zheng H, Liu X, et al. Whole-genome sequencing identifies recurrent mutations in hepatocellular carcinoma. Genome Res 2013;23:1422–33.
Qi LN, Li LQ, Chen YY, et al. Genome-wide and differential proteomic analysis of hepatitis B virus and aflatoxin B1 related hepatocellular carcinoma in Guangxi, China. PLoS One 2013;8:e83465.
Mayo SC, Mavros MN, Nathan H, et al. Treatment and prognosis of patients with fibrolamellar hepatocellular carcinoma: a national perspective. J Am Coll Surg 2014;218:196–205.
Torbenson M. Fibrolamellar carcinoma: 2012 update. Scientifica (Cairo) 2012;2012:743790.
Honeyman JN, Simon EP, Robine N, et al. Detection of a recurrent DNAJB1-PRKACA chimeric transcript in fibrolamellar hepatocellular carcinoma. Science 2014;343:1010–4.
Xu L, Hazard FK, Zmoos AF, et al. Genomic analysis of fibrolamellar hepatocellular carcinoma. Hum Mol Genet 2015;24:50–63.
Cheung J, Ginter C, Cassidy M, et al. Structural insights into mis-regulation of protein kinase A in human tumors. Proc Natl Acad Sci USA 2015;112:1374–9.
Amieux PS, McKnight GS. The essential role of RI alpha in the maintenance of regulated PKA activity. Ann N Y Acad Sci 2002;968:75–95.
Uhler MD, McKnight GS. Expression of cDNAs for two isoforms of the catalytic subunit of cAMP-dependent protein kinase. J Biol Chem 1987;262:15202–7.
Dell’Acqua ML, Scott JD. Protein kinase A anchoring. J Biol Chem 1997;272:12881–4.
Scott JD, Pawson T. Cell signaling in space and time: where proteins come together and when they’re apart. Science 2009;326:1220–4.
Pritchard CC, Salipante SJ, Koehler K, et al. Validation and implementation of targeted capture and sequencing for the detection of actionable mutation, copy number variation, and gene rearrangement in clinical cancer specimens. J Mol Diagn 2014;16:56–67.
Newlon MG, Roy M, Hausken ZE, Scott JD, Jennings PA. The A-kinase anchoring domain of type IIalpha cAMP-dependent protein kinase is highly helical. J Biol Chem 1997;272:23637–44.
Wu J, Brown SH, von Daake S, Taylor SS. PKA type IIalpha holoenzyme reveals a combinatorial strategy for isoform diversity. Science 2007;318:274–9.
Zick SK, Taylor SS. Interchain disulfide bonding in the regulatory subunit of cAMP-dependent protein kinase I. J Biol Chem 1982;257:2287–93.
Scott JD, Stofko RE, McDonald JR, Comer JD, Vitalis EA, Mangili JA. Type II regulatory subunit dimerization determines the subcellular localization of the cAMP-dependent protein kinase. J Biol Chem 1990;265:21561–6.
Carnegie GK, Means CK, Scott JD. A-kinase anchoring proteins: from protein complexes to physiology and disease. IUBMB Life 2009;61:394–406.
Smith FD, Reichow SL, Esseltine JL, et al. Intrinsic disorder within an AKAP-protein kinase A complex guides local substrate phosphorylation. Elife 2013;2:e01319.
Scott JD, Fischer EH, Demaille JG, Krebs EG. Identification of an inhibitory region of the heat-stable protein inhibitor of the cAMP-dependent protein kinase. Proc Natl Acad Sci USA 1985;82:4379–83.
Scott JD, Glaccum MB, Fischer EH, Krebs EG. Primary-structure requirements for inhibition by the heat-stable inhibitor of the cAMP-dependent protein kinase. Proc Natl Acad Sci USA 1986;83:1613–6.
Welch EJ, Jones BW, Scott JD. Networking with AKAPs: context-dependent regulation of anchored enzymes. Mol Interv 2010;10:86–97.
Beuschlein F, Fassnacht M, Assié G, et al. Constitutive activation of PKA catalytic subunit in adrenal Cushing’s syndrome. N Engl J Med 2014;370:1019–28.
Kirschner LS, Carney JA, Pack SD, et al. Mutations of the gene encoding the protein kinase A type I-alpha regulatory subunit in patients with the Carney complex. Nat Genet 2000;26:89–92.
Carnegie GK, Scott JD. A-kinase anchoring proteins and neuronal signaling mechanisms. Genes Dev 2003;17:1557–68.
Lania AG, Mantovani G, Ferrero S, et al. Proliferation of transformed somatotroph cells related to low or absent expression of protein kinase a regulatory subunit 1A protein. Cancer Res 2004;64:9193–8.
Mantovani G, Bondioni S, Ferrero S, et al. Effect of cyclic adenosine 3’,5’-monophosphate/protein kinase a pathway on markers of cell proliferation in nonfunctioning pituitary adenomas. J Clin Endocrinol Metab 2005;90:6721–4.
Riehle KJ, Yeh MM, Yu JJ, et al. mTORC1 and FGFR1 signaling in fibrolamellar hepatocellular carcinoma. Mod Pathol 2015;28:103–10.
Pringle DR, Vasko VV, Yu L, et al. Follicular thyroid cancers demonstrate dual activation of PKA and mTOR as modeled by thyroid-specific deletion of Prkar1a and Pten in mice. J Clin Endocrinol Metab 2014;99:E804–12.
Canton DA, Keene CD, Swinney K, et al. Gravin is a transitory effector of polo-like kinase 1 during cell division. Mol Cell 2012;48:547–59.
Carnegie GK, Soughayer J, Smith FD, et al. AKAP-Lbc mobilizes a cardiac hypertrophy signaling pathway. Mol Cell 2008;32:169–79.
Langeberg LK, Scott JD. Signalling scaffolds and local organization of cellular behaviour. Nat Rev Mol Cell Biol 2015;16:232–44.
Smith FD, Langeberg LK, Cellurale C, et al. AKAP-Lbc enhances cyclic AMP control of the ERK1/2 cascade. Nat Cell Biol 2010;12:1242–9.
Sunahara RK, Dessauer CW, Whisnant RE, Kleuss C, Gilman AG. Interaction of Gsalpha with the cytosolic domains of mammalian adenylyl cyclase. J Biol Chem 1997;272:22265–71.
Collier NA, Weinbren K, Bloom SR, Lee YC, Hodgson HJ, Blumgart LH. Neurotensin secretion by fibrolamellar carcinoma of the liver. Lancet 1984;1:538–40.
Dan YY, Riehle KJ, Lazaro C, et al. Isolation of multipotent progenitor cells from human fetal liver capable of differentiating into liver and mesenchymal lineages. Proc Natl Acad Sci USA 2006;103:9912–7.
Voet D, Voet JG. Biochemistry. 3rd edn. New York, NY: Wiley, 2004:480.
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The authors would like to thank Lorene Langeberg for her work helping to construct the figures for the manuscript.
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Riggle, K., Riehle, K., Kenerson, H. et al. Enhanced cAMP-stimulated protein kinase A activity in human fibrolamellar hepatocellular carcinoma. Pediatr Res 80, 110–118 (2016). https://doi.org/10.1038/pr.2016.36
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DOI: https://doi.org/10.1038/pr.2016.36
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