Persistent activation of Nrf2 through p62 in hepatocellular carcinoma cells
Tóm tắt
Suppression of autophagy is always accompanied by marked accumulation of p62, a selective autophagy substrate. Because p62 interacts with the Nrf2-binding site on Keap1, which is a Cullin 3–based ubiquitin ligase adapter protein, autophagy deficiency causes competitive inhibition of the Nrf2–Keap1 interaction, resulting in stabilization of Nrf2 followed by transcriptional activation of Nrf2 target genes. Herein, we show that liver-specific autophagy-deficient mice harbor adenomas linked to both the formation of p62- and Keap1-positive cellular aggregates and induction of Nrf2 targets. Importantly, similar aggregates were identified in more than 25% of human hepatocellular carcinomas (HCC), and induction of Nrf2 target genes was recognized in most of these tumors. Gene targeting of p62 in an HCC cell line markedly abrogates the anchorage-independent growth, whereas forced expression of p62, but not a Keap1 interaction-defective mutant, resulted in recovery of the growth defect. These results indicate the involvement of persistent activation of Nrf2 through the accumulation of p62 in hepatoma development.
Từ khóa
Tài liệu tham khảo
Bjørkøy, 2005, p62/SQSTM1 forms protein aggregates degraded by autophagy and has a protective effect on huntingtin-induced cell death, J. Cell Biol., 171, 603, 10.1083/jcb.200507002
Copple, 2010, Physical and functional interaction of sequestosome 1 with Keap1 regulates the Keap1-Nrf2 cell defense pathway, J. Biol. Chem., 285, 16782, 10.1074/jbc.M109.096545
Duran, 2008, The signaling adaptor p62 is an important NF-kappaB mediator in tumorigenesis, Cancer Cell., 13, 343, 10.1016/j.ccr.2008.02.001
Gao, 2010, Autophagy negatively regulates Wnt signalling by promoting Dishevelled degradation, Nat. Cell Biol., 12, 781, 10.1038/ncb2082
Hayes, 2009, NRF2 and KEAP1 mutations: permanent activation of an adaptive response in cancer, Trends Biochem. Sci., 34, 176, 10.1016/j.tibs.2008.12.008
Ichimura, 2008, Structural basis for sorting mechanism of p62 in selective autophagy, J. Biol. Chem., 283, 22847, 10.1074/jbc.M802182200
Inoue, 2000, Generation of mice with mitochondrial dysfunction by introducing mouse mtDNA carrying a deletion into zygotes, Nat. Genet., 26, 176, 10.1038/82826
Itakura, 2011, p62 Targeting to the autophagosome formation site requires self-oligomerization but not LC3 binding, J. Cell Biol., 192, 17, 10.1083/jcb.201009067
Jain, 2010, p62/SQSTM1 is a target gene for transcription factor NRF2 and creates a positive feedback loop by inducing antioxidant response element-driven gene transcription, J. Biol. Chem., 285, 22576, 10.1074/jbc.M110.118976
Jin, 2009, Cullin3-based polyubiquitination and p62-dependent aggregation of caspase-8 mediate extrinsic apoptosis signaling, Cell., 137, 721, 10.1016/j.cell.2009.03.015
Johansen, 2011, Selective autophagy mediated by autophagic adapter proteins, Autophagy., 7, 1, 10.4161/auto.7.3.14487
Kirkin, 2009, A role for ubiquitin in selective autophagy, Mol. Cell., 34, 259, 10.1016/j.molcel.2009.04.026
Kitamura, 2003, Retrovirus-mediated gene transfer and expression cloning: powerful tools in functional genomics, Exp. Hematol., 31, 1007, 10.1016/S0301-472X(03)00260-1
Komatsu, 2005, Impairment of starvation-induced and constitutive autophagy in Atg7-deficient mice, J. Cell Biol., 169, 425, 10.1083/jcb.200412022
Komatsu, 2007, Homeostatic levels of p62 control cytoplasmic inclusion body formation in autophagy-deficient mice, Cell., 131, 1149, 10.1016/j.cell.2007.10.035
Komatsu, 2010, The selective autophagy substrate p62 activates the stress responsive transcription factor Nrf2 through inactivation of Keap1, Nat. Cell Biol., 12, 213, 10.1038/ncb2021
Kraft, 2010, Selective autophagy: ubiquitin-mediated recognition and beyond, Nat. Cell Biol., 12, 836, 10.1038/ncb0910-836
Lau, 2010, A noncanonical mechanism of Nrf2 activation by autophagy deficiency: direct interaction between Keap1 and p62, Mol. Cell. Biol., 30, 3275, 10.1128/MCB.00248-10
Liang, 1999, Induction of autophagy and inhibition of tumorigenesis by beclin 1, Nature., 402, 672, 10.1038/45257
Mathew, 2009, Autophagy suppresses tumorigenesis through elimination of p62, Cell., 137, 1062, 10.1016/j.cell.2009.03.048
Meng, 2008, Targeted gene inactivation in zebrafish using engineered zinc-finger nucleases, Nat. Biotechnol., 26, 695, 10.1038/nbt1398
Mizushima, 2008, Autophagy fights disease through cellular self-digestion, Nature., 451, 1069, 10.1038/nature06639
Moscat, 2009, p62 at the crossroads of autophagy, apoptosis, and cancer, Cell., 137, 1001, 10.1016/j.cell.2009.05.023
Moscat, 2007, Signal integration and diversification through the p62 scaffold protein, Trends Biochem. Sci., 32, 95, 10.1016/j.tibs.2006.12.002
Motohashi, 2004, Nrf2-Keap1 defines a physiologically important stress response mechanism, Trends Mol. Med., 10, 549, 10.1016/j.molmed.2004.09.003
Nezis, 2008, Ref(2)P, the Drosophila melanogaster homologue of mammalian p62, is required for the formation of protein aggregates in adult brain, J. Cell Biol., 180, 1065, 10.1083/jcb.200711108
Padmanabhan, 2006, Structural basis for defects of Keap1 activity provoked by its point mutations in lung cancer, Mol. Cell., 21, 689, 10.1016/j.molcel.2006.01.013
Pankiv, 2007, p62/SQSTM1 binds directly to Atg8/LC3 to facilitate degradation of ubiquitinated protein aggregates by autophagy, J. Biol. Chem., 282, 24131, 10.1074/jbc.M702824200
Qu, 2003, Promotion of tumorigenesis by heterozygous disruption of the beclin 1 autophagy gene, J. Clin. Invest., 112, 1809, 10.1172/JCI20039
Riley, 2010, Ubiquitin accumulation in autophagy-deficient mice is dependent on the Nrf2-mediated stress response pathway: a potential role for protein aggregation in autophagic substrate selection, J. Cell Biol., 191, 537, 10.1083/jcb.201005012
Rubinsztein, 2006, The roles of intracellular protein-degradation pathways in neurodegeneration, Nature., 443, 780, 10.1038/nature05291
Santiago, 2008, Targeted gene knockout in mammalian cells by using engineered zinc-finger nucleases, Proc. Natl. Acad. Sci. USA., 105, 5809, 10.1073/pnas.0800940105
Sanz, 1999, The interaction of p62 with RIP links the atypical PKCs to NF-kappaB activation, EMBO J., 18, 3044, 10.1093/emboj/18.11.3044
Seligman, 1968, Nondroplet ultrastructural demonstration of cytochrome oxidase activity with a polymerizing osmiophilic reagent, diaminobenzidine (DAB), J. Cell Biol., 38, 1, 10.1083/jcb.38.1.1
Shibata, 2008, Genetic alteration of Keap1 confers constitutive Nrf2 activation and resistance to chemotherapy in gallbladder cancer, Gastroenterology., 135, 1358, 10.1053/j.gastro.2008.06.082
Shibata, 2008, Cancer related mutations in NRF2 impair its recognition by Keap1-Cul3 E3 ligase and promote malignancy, Proc. Natl. Acad. Sci. USA., 105, 13568, 10.1073/pnas.0806268105
Singh, 2006, Dysfunctional KEAP1-NRF2 interaction in non-small-cell lung cancer, PLoS Med., 3, e420, 10.1371/journal.pmed.0030420
Takamura, 2011, Autophagy-deficient mice develop multiple liver tumors, Genes Dev., 10.1101/gad.2016211
Tanida, 1999, Apg7p/Cvt2p: A novel protein-activating enzyme essential for autophagy, Mol. Biol. Cell., 10, 1367, 10.1091/mbc.10.5.1367
Villeneuve, 2010, Regulation of the Nrf2-Keap1 antioxidant response by the ubiquitin proteasome system: an insight into cullin-ring ubiquitin ligases, Antioxid. Redox Signal., 13, 1699, 10.1089/ars.2010.3211
Waguri, 2009, Biochemical and morphological detection of inclusion bodies in autophagy-deficient mice, Methods Enzymol., 453, 181, 10.1016/S0076-6879(08)04009-3
Yue, 2003, Beclin 1, an autophagy gene essential for early embryonic development, is a haploinsufficient tumor suppressor, Proc. Natl. Acad. Sci. USA., 100, 15077, 10.1073/pnas.2436255100