|
|
|
|
Vol. 55, Issue 5, 894-901, May 1999
Laboratory of Molecular & Cellular Toxicology, Institute of
Toxicology, College of Medicine, National Taiwan University, Taipei,
Taiwan (M.-L.K., S.-G.S.);
Institute of Biochemistry, Apoptosis plays a crucial role in maintaining genomic integrity
by selectively removing the most heavily damaged cells from the
population. Under that premise, the dysregulation of apoptosis may
result in an inappropriate survival of mutated cells. This study
demonstrates that ectopic expression of Bcl-2 effectively suppresses
benzene-active metabolites, 1,4-hydroquinone- and
1,4-benzoquinone-induced apoptosis in human leukemic HL-60 cells, as
evidenced by morphological changes and DNA fragmentation. Although
reactive oxygen species production largely contributes to the benzene
metabolites-induced apoptotic cell death, Bcl-2 fails to attenuate the
benzene metabolites-elicited increase of reactive oxygen species
in HL-60 cells, as confirmed by flow cytometry analysis. These data
suggest that Bcl-2 prevents benzene metabolites-induced apoptosis at
the downstream of oxidative damage events. This study also determines
the level of 8-hydroxydeoxyguanosine (8-OH-dGua), an indicator
for oxidative DNA damage, in neo- and Bcl-2-overexpressing HL-60 cells after treating with 1,4-hydroquinone or 1,4-benzoquinone. Interestingly, our results indicate that a
majority of the 8-OH-dGua is efficiently removed in neo
control cells within 3 to 6 h, whereas only 25 to 35% of
8-OH-dGua is repaired in Bcl-2 transfectants even for 24 h.
Similarly, another oxidative DNA base, thymine glycol, failed to repair
and was retained in genomic DNA of Bcl-2 transfectants. The
above findings suggest that Bcl-2 may retain benzene
metabolites-induced oxidative DNA damage in surviving cells. Indeed,
the failure of repairing 8-OH-dGua and thymine glycol in benzene
metabolites-treated Bcl-2 survivors increases the number of mutation
frequencies at the hprt locus. Results in this study
thus provide a novel benzene-induced carcinogenesis mechanism by which
up-regulation of Bcl-2 protein may promote the susceptibility to
benzene metabolites-induced mutagenesis by overriding apoptosis and
attenuating DNA repair capacity.
Copyright © 1999 by The American Society for Pharmacology and Experimental Therapeutics
This article has been cited by other articles:
![]() |
J. E. Deweese and N. Osheroff The DNA cleavage reaction of topoisomerase II: wolf in sheep's clothing Nucleic Acids Res., November 28, 2008; (2008) gkn937v1. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Zhao, F. Gao, Y. Zhang, K. Wei, Y. Liu, and X. Deng Bcl2 Inhibits Abasic Site Repair by Down-regulating APE1 Endonuclease Activity J. Biol. Chem., April 11, 2008; 283(15): 9925 - 9932. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. G. Cox and M. B. Hampton Bcl-2 over-expression promotes genomic instability by inhibiting apoptosis of cells exposed to hydrogen peroxide Carcinogenesis, October 1, 2007; 28(10): 2166 - 2171. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Hou, F. Gao, Q. Wang, J. Zhao, T. Flagg, Y. Zhang, and X. Deng Bcl2 Impedes DNA Mismatch Repair by Directly Regulating the hMSH2-hMSH6 Heterodimeric Complex J. Biol. Chem., March 23, 2007; 282(12): 9279 - 9287. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. Jin, W. S. May, F. Gao, T. Flagg, and X. Deng Bcl2 Suppresses DNA Repair by Enhancing c-Myc Transcriptional Activity J. Biol. Chem., May 19, 2006; 281(20): 14446 - 14456. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Silva, A. L. Kovalchuk, J. S. Kim, G. Klein, and S. Janz BCL2 Accelerates Inflammation-induced BALB/c Plasmacytomas and Promotes Novel Tumors with Coexisting T(12;15) and T(6;15) Translocations Cancer Res., December 15, 2003; 63(24): 8656 - 8663. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Canitrot, R. Falinski, T. Louat, G. Laurent, C. Cazaux, J.-S. Hoffmann, D. Lautier, and T. Skorski p210 BCR/ABL kinase regulates nucleotide excision repair (NER) and resistance to UV radiation Blood, October 1, 2003; 102(7): 2632 - 2637. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Bernstein, H. Holubec, J. A. Warneke, H. Garewal, D. L. Earnest, C. M. Payne, D. J. Roe, H. Cui, E. L. Jacobson, and C. Bernstein Patchy Field Defects of Apoptosis Resistance and Dedifferentiation in Flat Mucosa of Colon Resections From Colon Cancer Patients Ann. Surg. Oncol., June 1, 2002; 9(5): 505 - 517. [Abstract] [Full Text] [PDF] |
||||
![]() |
M.-T. Lin, C.-Y. Juan, K.-J. Chang, W.-J. Chen, and M.-L. Kuo IL-6 inhibits apoptosis and retains oxidative DNA lesions in human gastric cancer AGS cells through up-regulation of anti-apoptotic gene mcl-1 Carcinogenesis, December 1, 2001; 22(12): 1947 - 1953. [Abstract] [Full Text] [PDF] |
||||
![]() |
S.-G. Shiah, S.-E. Chuang, and M.-L. Kuo Involvement of Asp-Glu-Val-Asp-Directed, Caspase-Mediated Mitogen-Activated Protein Kinase Kinase 1 Cleavage, c-Jun N-Terminal Kinase Activation, and Subsequent Bcl-2 Phosphorylation for Paclitaxel-Induced Apoptosis in HL-60 Cells Mol. Pharmacol., February 1, 2001; 59(2): 254 - 262. [Abstract] [Full Text] |
||||