Inhibition of Autophagy by Targeting ATG4B: Promises and Challenges of An Emerging Anti-cancer Strategy

Author(s): Kelly Lien, Michelle Rocha, Elisa Tran, Van C. Hoang, Annabelle Chow, Urban Emmenegger

Journal Name: Clinical Cancer Drugs

Volume 2 , Issue 1 , 2015


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Abstract:

Aside from its function in cellular homeostasis, autophagy enables cells to dispose of damaged cellular components and to recycle metabolites in response to cellular stress. Of particular interest is the context-dependent role of autophagy in cancer. Autophagy has been shown to inhibit tumor growth in the early stages of carcinogenesis, yet promotes the progression of previously established tumors. The characterization of potent, specific autophagy inhibitors with novel mechanisms of action is a very active area of research. ATG4B is one of four mammalian ATG4 orthologues and cleaves the ubiquitin-like ATG8 mammalian orthologues (e.g. pro-LC3B), a crucial step in the formation of the mature autophagosome. This review provides an overview of the role of ATG4 orthologues during autophagy, describes cancerspecific ATG4 functions and discusses the role of ATG4B inhibition as an emerging anti-cancer strategy. While available data show that impairing ATG4B typically decreases the growth of human cancer cell lines in vitro and in vivo, under certain circumstances ATG4B inhibition may also be detrimental. On the other hand, pre-clinical testing of ATG4B inhibitors and the analysis of ATG4B knockout mice suggest that ATG4B inhibition should be very well tolerated. As is the case with other autophagy inhibitors, future studies would benefit from the development of suitable predictive biomarkers of response and tools to monitor autophagy activity.

Keywords: ATG4, ATG4B, autophagy, cancer, autophagy inhibition, targeting.

[1]
Choi AM, Ryter SW, Levine B. Autophagy in human health and disease. N Engl J Med 2013; 368(7): 651-62.
[2]
Yang Z, Klionsky DJ. Mammalian autophagy: core molecular machinery and signaling regulation. Curr Opin Cell Biol 2010; 22(2): 124-31.
[3]
White E. Deconvoluting the context-dependent role for autophagy in cancer. Nat Rev Cancer 2012; 12(6): 401-10.
[4]
Rubinstein AD, Kimchi A. Life in the balance - a mechanistic view of the crosstalk between autophagy and apoptosis. J Cell Sci 2012; 125(Pt 22): 5259-68.
[5]
Shen S, Kepp O, Kroemer G. The end of autophagic cell death? Autophagy 2012; 8(1): 1-3.
[6]
Clarke PG, Puyal J. Autophagic cell death exists. Autophagy 2012; 8(6): 867-9.
[7]
Carew JS, Kelly KR, Nawrocki ST. Autophagy as a target for cancer therapy: new developments. Cancer Manag Res 2012; 4: 357-65.
[8]
Wu WK, Coffelt SB, Cho CH, et al. The autophagic paradox in cancer therapy. Oncogene 2012; 31(8): 939-53.
[9]
Gorski SM, Ries J, Lum JJ. Targeting autophagy: the Achilles’ heel of cancer. Autophagy 2012; 8(8): 1279-80.
[10]
Janku F, McConkey DJ, Hong DS, Kurzrock R. Autophagy as a target for anticancer therapy. Nat Rev Clin Oncol 2011; 8(9): 528-39.
[11]
Kimmelman AC. The dynamic nature of autophagy in cancer. Genes Dev 2011; 25(19): 1999-2010.
[12]
Liu B, Cheng Y, Liu Q, Bao JK, Yang JM. Autophagic pathways as new targets for cancer drug development. Acta Pharmacol Sin 2010; 31(9): 1154-64.
[13]
Behrends C, Fulda S. Receptor proteins in selective autophagy. Int J Cell Biol 2012; 2012: 673290.
[14]
Mathew R, Karp CM, Beaudoin B, et al. Autophagy suppresses tumorigenesis through elimination of p62. Cell 2009; 137(6): 1062-75.
[15]
Duran A, Linares JF, Galvez AS, et al. The signaling adaptor p62 is an important NF-kappaB mediator in tumorigenesis. Cancer Cell 2008; 13(4): 343-54.
[16]
Yue Z, Jin S, Yang C, Levine AJ, Heintz N. Beclin 1, an autophagy gene essential for early embryonic development, is a haploinsufficient tumor suppressor. Proc Natl Acad Sci USA 2003; 100(25): 15077-82.
[17]
Qu X, Yu J, Bhagat G, et al. Promotion of tumorigenesis by heterozygous disruption of the beclin 1 autophagy gene. J Clin Invest 2003; 112(12): 1809-20.
[18]
Takamura A, Komatsu M, Hara T, Sakamoto A, Kishi C, Waguri S, et al. Autophagy-deficient mice develop multiple liver tumors. Genes Dev 2011; 25(8): 795-800.
[19]
Amir M, Zhao E, Fontana L, et al. Inhibition of hepatocyte autophagy increases tumor necrosis factor-dependent liver injury by promoting caspase-8 activation. Cell Death Differ 2013; 20(7): 878-87.
[20]
Yang S, Wang X, Contino G, Liesa M, Sahin E, Ying H, et al. Pancreatic cancers require autophagy for tumor growth. Genes Dev 2011; 25(7): 717-29.
[21]
Degenhardt K, Mathew R, Beaudoin B, et al. Autophagy promotes tumor cell survival and restricts necrosis, inflammation, and tumorigenesis. Cancer Cell 2006; 10(1): 51-64.
[22]
Cheong H, Lu C, Lindsten T, Thompson CB. Therapeutic targets in cancer cell metabolism and autophagy. Nat Biotechnol 2012; 30(7): 671-8.
[23]
Rodriguez-Rocha H, Garcia-Garcia A, Panayiotidis MI, Franco R. DNA damage and autophagy. Mutat Res 2011; 711(1-2): 158-66.
[24]
Rubinsztein DC, Codogno P, Levine B. Autophagy modulation as a potential therapeutic target for diverse diseases. Nat Rev Drug Discov 2012; 11(9): 709-30.
[25]
Yang ZJ, Chee CE, Huang S, Sinicrope FA. The role of autophagy in cancer: therapeutic implications. Mol Cancer Ther 2011; 10(9): 1533-41.
[26]
McAfee Q, Zhang Z, Samanta A, et al. Autophagy inhibitor Lys05 has single-agent antitumor activity and reproduces the phenotype of a genetic autophagy deficiency. Proc Natl Acad Sci USA 2012; 109(21): 8253-8.
[27]
Solomon VR, Lee H. Chloroquine and its analogs: a new promise of an old drug for effective and safe cancer therapies. Eur J Pharmacol 2009; 625(1-3): 220-33.
[28]
Kawai A, Uchiyama H, Takano S, Nakamura N, Ohkuma S. Autophagosome-lysosome fusion depends on the pH in acidic compartments in CHO cells. Autophagy 2007; 3(2): 154-7.
[29]
Sotelo J, Briceno E, Lopez-Gonzalez MA. Adding chloroquine to conventional treatment for glioblastoma multiforme: a randomized, double-blind, placebo-controlled trial. Ann Intern Med 2006; 144(5): 337-43.
[30]
Ducharme J, Farinotti R. Clinical pharmacokinetics and metabolism of chloroquine. Focus on recent advancements. Clin Pharmacokinet 1996; 31(4): 257-74.
[31]
Kimura T, Takabatake Y, Takahashi A, Isaka Y. Chloroquine in cancer therapy: a double-edged sword of autophagy. Cancer Res 2013; 73(1): 3-7.
[32]
Maycotte P, Aryal S, Cummings CT, Thorburn J, Morgan MJ, Thorburn A. Chloroquine sensitizes breast cancer cells to chemotherapy independent of autophagy. Autophagy 2012; 8(2): 200-12.
[33]
Goodall ML, Wang T, Martin KR, Kortus MG, Kauffman AL, Trent JM, et al. Development of potent autophagy inhibitors that sensitize oncogenic BRAF V600E mutant melanoma tumor cells to vemurafenib. Autophagy 2014; 10(6): 1120-36.
[34]
Shu CW, Madiraju C, Zhai D, et al. High-throughput fluorescence assay for small-molecule inhibitors of autophagins/Atg4. J Biomol Screen 2011; 16(2): 174-82.
[35]
Donohue E, Tovey A, Vogl AW, et al. Inhibition of autophagosome formation by the benzoporphyrin derivative verteporfin. J Biol Chem 2011; 286(9): 7290-300.
[36]
Miller S, Tavshanjian B, Oleksy A, et al. Shaping development of autophagy inhibitors with the structure of the lipid kinase Vps34. Science 2010; 327(5973): 1638-42.
[37]
Liu J, Xia H, Kim M, et al. Beclin1 controls the levels of p53 by regulating the deubiquitination activity of USP10 and USP13. Cell 2011; 147(1): 223-34.
[38]
Nguyen TG, Honson NS, Arns S, Davis TL, Dhe-Paganon S, Kovacic S, et al. Development of fluorescent substrates and assays for the key autophagy-related cysteine protease enzyme, ATG4B. Assay Drug Dev Technol 2014; 12(3): 176-89.
[39]
Ronan B, Flamand O, Vescovi L, et al. A highly potent and selective Vps34 inhibitor alters vesicle trafficking and autophagy. Nat Chem Biol 2014; 10(12): 1013-9.
[40]
Bago R, Malik N, Munson MJ, et al. Characterization of VPS34-IN1, a selective inhibitor of Vps34, reveals that the phosphatidylinositol 3-phosphate-binding SGK3 protein kinase is a downstream target of class III phosphoinositide 3-kinase. Biochem J 2014; 463(3): 413-27.
[41]
Dowdle WE, Nyfeler B, Nagel J, et al. Selective VPS34 inhibitor blocks autophagy and uncovers a role for NCOA4 in ferritin degradation and iron homeostasis in vivo. Nat Cell Biol 2014; 16(11): 1069-79.
[42]
Pasquier B, El-Ahmad Y, Filoche-Romme B, et al. Discovery of (2S)-8-[(3R)-3-methylmor- pholin-4-yl]-1-(3-methyl-2-oxobutyl)-2-(trifluoromethyl)- 3,4-dihydro-2H-pyrimido[1,2-a]pyrimidin-6-one: a novel potent and selective inhibitor of Vps34 for the treatment of solid tumors. J Med Chem 2015; 58(1): 376-400.
[43]
Till A, Subramani S. A balancing act for autophagin. J Clin Invest 2010; 120(7): 2273-6.
[44]
Klionsky DJ, Baehrecke EH, Brumell JH, et al. A comprehensive glossary of autophagy-related molecules and processes (2nd edition) Autophagy 2011; 7(11): 1273-94 .
[45]
Fujita N, Hayashi-Nishino M, Fukumoto H, et al. An Atg4B mutant hampers the lipidation of LC3 paralogues and causes defects in autophagosome closure. Mol Biol Cell 2008; 19(11): 4651-9.
[46]
Kirisako T, Ichimura Y, Okada H, et al. The reversible modification regulates the membrane-binding state of Apg8/Aut7 essential for autophagy and the cytoplasm to vacuole targeting pathway. J Cell Biol 2000; 151(2): 263-76.
[47]
Nakatogawa H, Ishii J, Asai E, Ohsumi Y. Atg4 recycles inappropriately lipidated Atg8 to promote autophagosome biogenesis. Autophagy 2012; 8(2): 177-86.
[48]
Fujita N, Noda T, Yoshimori T. Atg4B(C74A) hampers autophagosome closure: a useful protein for inhibiting autophagy. Autophagy 2009; 5(1): 88-9.
[49]
Hemelaar J, Lelyveld VS, Kessler BM, Ploegh HL. A single protease, Apg4B, is specific for the autophagy-related ubiquitin-like proteins GATE-16, MAP1-LC3, GABARAP, and Apg8L. J Biol Chem 2003; 278(51): 51841-50.
[50]
Li M, Hou Y, Wang J, Chen X, Shao ZM, Yin XM. Kinetics comparisons of mammalian Atg4 homologues indicate selective preferences toward diverse Atg8 substrates. J Biol Chem 2011; 286(9): 7327-38.
[51]
Shpilka T, Weidberg H, Pietrokovski S, Elazar Z. Atg8: an autophagy-related ubiquitin-like protein family. Genome Biol 2011; 12(7): 226.
[52]
Betin VM, Lane JD. Caspase cleavage of Atg4D stimulates GABARAP-L1 processing and triggers mitochondrial targeting and apoptosis. J Cell Sci 2009; 122(Pt 14): 2554-66.
[53]
Marino G, Fernandez AF, Cabrera S, Lundberg YW, Cabanillas R, Rodriguez F, et al. Autophagy is essential for mouse sense of balance. J Clin Invest 2010; 120(7): 2331-44.
[54]
Read R, Savelieva K, Baker K, Hansen G, Vogel P. Histopathological and neurological features of Atg4b knockout mice. Vet Pathol 2011; 48(2): 486-94.
[55]
Cabrera S, Fernandez AF, Marino G, Aguirre A, Suarez MF, Espanol Y, et al. ATG4B/autophagin-1 regulates intestinal homeostasis and protects mice from experimental colitis. Autophagy 2013; 9(8): 1188-200.
[56]
Lopez-Alonso I, Aguirre A, Gonzalez-Lopez A, Fernandez AF, Amado-Rodriguez L, Astudillo A, et al. Impairment of autophagy decreases ventilator-induced lung injury by blockade of the NF-kappaB pathway. Am J Physiol Lung Cell Mol Physiol 2013; 304(12): L844-52.
[57]
Marino G, Salvador-Montoliu N, Fueyo A, Knecht E, Mizushima N, Lopez-Otin C. Tissue-specific autophagy alterations and increased tumorigenesis in mice deficient in Atg4C/autophagin-3. J Biol Chem 2007; 282(25): 18573-83.
[58]
Wu C, Macleod I, Su AI. BioGPS and MyGene.info: organizing online, gene-centric information. Nucleic Acids Res 2013; 41(Database issue): D561-5.
[59]
Su AI, Wiltshire T, Batalov S, et al. A gene atlas of the mouse and human protein-encoding transcriptomes. Proc Natl Acad Sci USA 2004; 101(16): 6062-7.
[60]
Guo L, Huang JX, Liu Y, et al. Transactivation of Atg4b by C/EBPbeta promotes autophagy to facilitate adipogenesis. Mol Cell Biol 2013; 33(16): 3180-90.
[61]
He C, Zhu H, Zhang W, et al. 7-Ketocholesterol induces autophagy in vascular smooth muscle cells through Nox4 and Atg4B. Am J Pathol 2013; 183(2): 626-37.
[62]
Cleveland BM, Weber GM. Effects of triploidy on growth and protein degradation in skeletal muscle during recovery from feed deprivation in juvenile rainbow trout (Oncorhynchus mykiss). Comp Biochem Physiol A Mol Integr Physiol 2013; 166(1): 128-37.
[63]
Smith HK, Matthews KG, Oldham JM, et al. Translational signalling, atrogenic and myogenic gene expression during unloading and reloading of skeletal muscle in myostatin-deficient mice. PLoS One 2014; 9(4): e94356.
[64]
Dreux M, Chisari FV. Viruses and the autophagy machinery. Cell Cycle 2010; 9(7): 1295-307.
[65]
Zang L, Xu Q, Ye Y, et al. Autophagy enhanced phagocytosis of apoptotic cells by oridonin-treated human histocytic lymphoma U937 cells. Arch Biochem Biophys 2012; 518(1): 31-41.
[66]
Korkmaz G, le Sage C, Tekirdag KA, Agami R, Gozuacik D. miR-376b controls starvation and mTOR inhibition-related autophagy by targeting ATG4C and BECN1. Autophagy 2012; 8(2): 165-76.
[67]
Frankel LB, Wen J, Lees M, et al. microRNA-101 is a potent inhibitor of autophagy. EMBO J 2011; 30(22): 4628-41.
[68]
Apel A, Herr I, Schwarz H, Rodemann HP, Mayer A. Blocked autophagy sensitizes resistant carcinoma cells to radiation therapy. Cancer Res 2008; 68(5): 1485-94.
[69]
Li M, Chen X, Ye QZ, Vogt A, Yin XM. A high-throughput FRET-based assay for determination of Atg4 activity. Autophagy 2012; 8(3): 401-12.
[70]
Akin D, Wang SK, Habibzadegah-Tari P, et al. A novel ATG4B antagonist inhibits autophagy and has a negative impact on osteosarcoma tumors. Autophagy 2014; 10(11): 2021-35.
[71]
Wensing AM, van Maarseveen NM, Nijhuis M. Fifteen years of HIV Protease Inhibitors: raising the barrier to resistance. Antiviral Res 2010; 85(1): 59-74.
[72]
Lebovitz CB, Bortnik SB, Gorski SM. Here, there be dragons: charting autophagy-related alterations in human tumors. Clin Cancer Res 2012; 18(5): 1214-26.
[73]
Reinhold WC, Sunshine M, Liu H, et al. CellMiner: a web-based suite of genomic and pharmacologic tools to explore transcript and drug patterns in the NCI-60 cell line set. Cancer Res 2012; 72(14): 3499-511.
[74]
Mizuno H, Kitada K, Nakai K, Sarai A. PrognoScan: a new database for meta-analysis of the prognostic value of genes. BMC Med Genomics 2009; 2: 18.
[75]
Betin VM, Lane JD. Atg4D at the interface between autophagy and apoptosis. Autophagy 2009; 5(7): 1057-9.
[76]
Liu PF, Leung CM, Chang YH, et al. ATG4B promotes colorectal cancer growth independent of autophagic flux. Autophagy 2014; 10(8): 1454-65.
[77]
Rothe K, Lin H, Lin KB, Leung A, Wang HM, Malekesmaeili M, et al. The core autophagy protein ATG4B is a potential biomarker and therapeutic target in CML stem/progenitor cells. Blood 2014; 123(23): 3622-34.
[78]
Tran E, Chow A, Goda T, et al. Context-dependent role of ATG4B as target for autophagy inhibition in prostate cancer therapy. Biochem Biophys Res Commun 2013; 441(4): 726-31.
[79]
Ohsumi Y. Molecular dissection of autophagy: two ubiquitin-like systems. Nat Rev Mol Cell Biol 2001; 2(3): 211-6.
[80]
Wolpin BM, Rubinson DA, Wang X, et al. Phase II and pharmacodynamic study of autophagy inhibition using hydroxychloroquine in patients with metastatic pancreatic adenocarcinoma. Oncologist 2014; 19(6): 637-8.
[81]
Rosenfeld MR, Ye X, Supko JG, et al. A phase I/II trial of hydroxychloroquine in conjunction with radiation therapy and concurrent and adjuvant temozolomide in patients with newly diagnosed glioblastoma multiforme. Autophagy 2014; 10(8): 1359-68.
[82]
Rangwala R, Chang YC, Hu J, et al. Combined MTOR and autophagy inhibition: phase I trial of hydroxychloroquine and temsirolimus in patients with advanced solid tumors and melanoma. Autophagy 2014; 10(8): 1391-402.
[83]
Thorburn A, Thamm DH, Gustafson DL. Autophagy and cancer therapy. Mol Pharmacol 2014; 85(6): 830-8.
[84]
Gewirtz DA. An autophagic switch in the response of tumor cells to radiation and chemotherapy. Biochem Pharmacol 2014; 90(3): 208-11.
[85]
Amaravadi R, Debnath J. Mouse models address key concerns regarding autophagy inhibition in cancer therapy. Cancer Discov 2014; 4(8): 873-5.
[86]
Scherz-Shouval R, Shvets E, Fass E, Shorer H, Gil L, Elazar Z. Reactive oxygen species are essential for autophagy and specifically regulate the activity of Atg4. EMBO J 2007; 26(7): 1749-60.


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Article Details

VOLUME: 2
ISSUE: 1
Year: 2015
Published on: 31 March, 2015
Page: [61 - 70]
Pages: 10
DOI: 10.2174/2212697X02666150331202809

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