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Bcl-2 overexpression in PhIP-induced colon tumors: cloning of the rat Bcl-2 promoter and characterization of a pathway involving β-catenin, c-Myc and E2F1

Abstract

β-Catenin/T-cell factor (Tcf) signaling is constitutively active in the majority of human colorectal cancers, and there are accompanying changes in Bcl-2 expression. Similarly, 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP)-induced colon tumors in the rat have increased β-catenin and elevated Bcl-2. To examine the possible direct transcriptional regulation of rat Bcl-2 by β-catenin/Tcf, we cloned and characterized the corresponding promoter region and found 70.1% similarity with its human counterpart, BCL2. Bcl-2 promoter activity was increased in response to LiCl and exogenous β-catenin, including oncogenic mutants of β-catenin found in PhIP-induced colon tumors. Protein/DNA arrays identified E2F1, but not β-catenin/Tcf, as interacting most strongly with the rat Bcl-2 promoter. Exogenous E2F1 increased the promoter activity of rat Bcl-2, except in mutants lacking the E2F1 sites. As expected, β-catenin induced its downstream target c-Myc, as well as E2F1 and Bcl-2, and this was blocked by siRNA to c-Myc or E2F1. These findings suggest an indirect pathway for Bcl-2 over-expression in PhIP-induced colon tumors involving β-catenin, c-Myc and E2F1.

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References

  • Aberle H, Bauer A, Stappert J, Kispert A, Kemler R . (1997). β-catenin is a target for the ubiquitin-proteasome pathway. EMBO J 16: 3797–3804.

    Article  CAS  Google Scholar 

  • Al-Fageeh M, Li Q, Dashwood WM, Myzak MC, Dashwood RH . (2004). Phosphorylation and ubiquitination of oncogenic mutants of β-catenin containing substitutions at Asp32. Oncogene 23: 4839–4846.

    Article  CAS  Google Scholar 

  • Bedi A, Pasricha PJ, Akhtar AJ, Barber JP, Bedi GC, Giardiello FM et al. (1995). Inhibition of apoptosis during development of colorectal cancer. Cancer Res 55: 1811–1816.

    CAS  PubMed  Google Scholar 

  • Behrens J . (2005). The role of the Wnt signalling pathway in colorectal tumorigenesis. Biochem Soc Trans 33: 672–675.

    Article  CAS  Google Scholar 

  • Blum CA, Xu M, Orner GA, Fong AT, Bailey GS, Stoner GD et al. (2001). β-Catenin mutation in rat colon tumors initiated by 1,2-dimethylhydrazine and 2-amino-3-methylimidazo[4,5-f]quinoline, and the effect of post-initiation treatment with chlorophyllin and indole-3-carbinol. Carcinogenesis 22: 315–320.

    Article  CAS  Google Scholar 

  • Blum CA, Tanaka T, Zhong X, Li Q, Dashwood WM, Pereira C et al. (2003). Mutational analysis of Ctnnb1 and Apc in tumors from rats given 1,2-dimethylhydrazine or 2-amino-3-methylimidazo[4,5-f]quinoline: mutational ‘hotspots’ and the relative expression of β-catenin and c-jun. Mol Carcinogen 36: 195–203.

    Article  CAS  Google Scholar 

  • Dashwood RH, Suzui M, Nakagama H, Sugimura T, Nagao M . (1998). High frequency of β-catenin (Ctnnb1) mutations in the colon tumors induced by two heterocyclic amines in the F344 rat. Cancer Res 58: 1127–1129.

    CAS  PubMed  Google Scholar 

  • Dashwood WM, Orner GA, Dashwood RH . (2002). Inhibition of β-catenin/Tcf activity by white tea, green tea, and epigallocatechin-3-gallate (EGCG): minor contribution of H2O2 at physiologically relevant EGCG concentrations. Biochem Biophys Res Commun 296: 584–588.

    Article  CAS  Google Scholar 

  • Dashwood WM, Carter O, Al-Fageeh M, Li Q, Dashwood RH . (2005). Lysosomal trafficking of β-catenin induced by the tea polyphenol epigallocatechin-3-gallate. Mutat Res 591: 161–172.

    Article  CAS  Google Scholar 

  • Fujiwara K, Ochiai M, Ohta T, Ohki M, Aburatani H, Nagao M et al. (2004). Global gene expression analysis of rat colon cancers induced by a food-borne carcinogen, 2-amino-3-methylimidazo[4,5-f]quinoline. Carcinogenesis 25: 1495–1505.

    Article  CAS  Google Scholar 

  • Gomez-Manzano C, Mitlianga P, Fueyo J, Lee HY, Hu M, Spurgers KB et al. (2001). Transfer of E2F-1 to human glioma cells results in transcriptional up-regulation of Bcl-2. Cancer Res 61: 6693–6697.

    CAS  PubMed  Google Scholar 

  • Grossmann M, O'Reilly LA, Gugasyan R, Strasser A, Adams JM, Gerondakis S . (2000). The anti-apoptotic activities of Rel and RelA required during B-cell maturation involve the regulation of Bcl-2 expression. EMBO J 19: 6351–6360.

    Article  CAS  Google Scholar 

  • Harigai M, Miyashita T, Hanada M, Reed JC . (1996). A cis-acting element in the BCL-2 gene controls expression through translational mechanisms. Oncogene 12: 1369–1374.

    CAS  PubMed  Google Scholar 

  • Hayashi R, Luk H, Horio D, Dashwood RH . (1996). Inhibition of apoptosis in colon tumors induced in the rat by 2-amino-3-methylimidazo[4,5-f]quinoline. Cancer Res 56: 4307–4310.

    CAS  PubMed  Google Scholar 

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

    Article  CAS  Google Scholar 

  • Huang X, Wu DY, Chen G, Manji H, Chen DF . (2003). Support of retinal ganglion cell survival and axon regeneration by lithium through a Bcl-2-dependent mechanism. Invest Ophthalmol Vis Sci 44: 347–354.

    Article  Google Scholar 

  • Li Q, Dashwood WM, Zhong X, Al-Fageeh M, Dashwood RH . (2004). Cloning of the rat β-catenin gene (Ctnnb1) promoter and its functional analysis compared with the Catnb and CTNNB1 promoters. Genomics 83: 231–242.

    Article  CAS  Google Scholar 

  • Li Q, Dashwood RH . (2004). Activator protein-2α associates with adenomatous polyposis coli/β-catenin and inhibits β-catenin/T-cell factor transcriptional activity in colorectal cancer cells. J Biol Chem 269: 45669–45675.

    Article  Google Scholar 

  • Manji HK, Moore GJ, Chen G . (2000). Lithium up-regulates the cytoprotective protein Bcl-2 in the CNS in vivo: a role for neurotrophic and neuroprotective effects in manic depressive illness. J Clin Psychiatry 61: 82–96.

    CAS  PubMed  Google Scholar 

  • Mayo MW, Wang C, Drouin SS, Madrid LV, Marshall AF, Reed JC et al. (1999). WT1 modulates apoptosis by transcriptionally upregulating the bcl-2 proto-oncogene. EMBO J 18: 3990–4003.

    Article  CAS  Google Scholar 

  • Muller H, Bracken AP, Vernell R, Moroni MC, Christians F, Grassilli E et al. (2001). E2Fs regulate the expression of genes involved in differentiation, development, proliferation, and apoptosis. Genes Dev 15: 267–285.

    Article  CAS  Google Scholar 

  • Ochiai M, Ushigome M, Fujiwara K, Ubagai T, Kawamori T, Sugimura T et al. (2003). Characterization of dysplastic aberrant crypt foci in the rat colon induced by 2-amino-3-methylimidazo[4,5-f]quinoline. Am J Pathol 163: 1607–1614.

    Article  CAS  Google Scholar 

  • O'Donnell K, Wentzel EA, Zeller KI, Dang CV, Mendell JT . (2005). c-Myc-regulated microRNAs modulate E2F1 expression. Nature 435: 839–843.

    Article  CAS  Google Scholar 

  • Park S, Gwak J, Cho M, Song T, Won J, Kim DE et al. (2006). Hexachlorophene inhibits Wnt/β-catenin pathway by promoting Siah-mediated β-catenin degradation. Mol Pharmacol 70: 960–966.

    Article  CAS  Google Scholar 

  • Pugazhenthi S, Miller E, Sable C, Young P, Heidenreich KA, Boxer LM et al. (1999). Insulin-like growth factor-1 induces bcl-2 promoter through a transcription factor cAMP-response element-binding protein. J Biol Chem 274: 2829–2837.

    Article  CAS  Google Scholar 

  • Romero O, Martinez AC, Camonis J, Rebollo A . (1999). Aiolos transcription factor controls cell death in T cells by regulating Bcl-2 expression and its cellular localization. EMBO J 18: 3419–3430.

    Article  CAS  Google Scholar 

  • Seto M, Jaeger U, Hockett RD, Graninger W, Bennett S, Goldman P et al. (1988). Alternative promoters and exons, somatic mutation and deregulation of the Bcl-2-Ig fusion gene in lymphoma. EMBO J 7: 123–131.

    Article  CAS  Google Scholar 

  • Salomoni P, Perrotti D, Martinez R, Franceschi C, Calabretta B . (1997). Resistance to apoptosis in CTLL-2 cells constitutively expressing c-Myb is associated with induction of BCL-2 expression and c-MYB-dependent regulation of bcl-2 promoter activity. Proc Natl Acad Sci USA 94: 3296–3301.

    Article  CAS  Google Scholar 

  • Smith MD, Ensor EA, Coffin RS, Boxer LM, Latchman DS . (1998). Bcl-2 transcription from the proximal P2 promoter is activated in neuronal cells by the Brn-3a POU family transcription factor. J Biol Chem 273: 16715–16722.

    Article  CAS  Google Scholar 

  • Tamatani M, Che YH, Matsuzaki H, Ogawa S, Okado S, Miyake S et al. (1999). Tumor necrosis factor induces Bcl-2 and Bcl-x expression through NFκB activation in primary hippocampal neurons. J Biol Chem 274: 8531–8538.

    Article  CAS  Google Scholar 

  • Wilson BE, Mochon E, Boxer LM . (1996). Induction of bcl-2 expression by phosphorylated CREB proteins during B-cell activation and rescue from apopotosis. Mol Cell Biol 16: 5546–5556.

    Article  CAS  Google Scholar 

  • Zeng G, Gao L, Xia T, Tencomnao T, Yu RK . (2003). Characterization of the 5′-flanking fragment of the human GM3-synthase gene. Biochim Biophys Acta 1625: 30–35.

    Article  CAS  Google Scholar 

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Acknowledgements

Minako Nagao and Hideaki Inamori are gratefully acknowledged for their help in the studies with PhIP-induced colon tumors, which were supported by a fellowship from the Foundation for Promotion of Cancer Research, Tokyo, Japan. We thank Mark van de Wetering and Hans Clevers of University Hospital Utrecht, The Netherlands, for the wild-type β-catenin construct. This work was supported by NIH grants CA65525, CA80176 and CA90890, and by NIEHS center grant P30 ES00210.

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Correspondence to R H Dashwood.

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Li, Q., Dashwood, W., Zhong, X. et al. Bcl-2 overexpression in PhIP-induced colon tumors: cloning of the rat Bcl-2 promoter and characterization of a pathway involving β-catenin, c-Myc and E2F1. Oncogene 26, 6194–6202 (2007). https://doi.org/10.1038/sj.onc.1210438

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