Carcinogenesis, Vol. 21, No. 5, 1067-1068,
May 2000
© 2000 Oxford University Press
Letters to the Editor |
Mitomycin C and diepoxybutane action mechanisms and FANCC protein functions: further insights into the role for oxidative stress in Fanconi's anaemia phenotype
Italian National Cancer Institute, G.Pascale Foundation, via M.Semmola,I-80131 Naples, Italy Email: gbpagano{at}tin.it
Abstract
Evidence for redox-dependent toxicities of mitomycin C (MMC) and diepoxybutane (DEB), through different mechanisms, has been related to the phenotypic defect(s) of Fanconi's anaemia (FA) cells, due to their excess sensitivity to these agents. Recent data have pointed to interactions of the FANCC protein (encoded by the FA complementation group C gene, FA-C) with NADPH cytochrome P450 reductase and glutathione S-transferase (GST), two activities involved in either triggering or detoxifying reactive intermediates, including xenobiotics and reactive oxygen species. A body of evidence points to: (i) oxygen hypersensitivity of FA cells; (ii) oxygen-dependent MMC and DEB toxicity; (iii) excess oxidative DNA damage in FA cells; and (iv) DEB-induced glutathione depletion and GST inhibition. The available evidence corroborates the previously suggested role for oxidative stress in FA phenotype and disease progression, shedding new light on the redox-dependent mechanisms in MMC and DEB toxicities, and suggesting a direct association of oxidative stress with the primary genetic defect in FA.
Mitomycin C (MMC) and diepoxybutane (DEB): redox-dependent versus cross-linking mechanisms
Korkina et al. (1) identify redox-related action mechanisms of MMC and DEB, that include oxygen-dependent toxicity both for MMC (as previously recognised) and for DEB (as first reported by Korkina et al. in ref. 1). Moreover, MMC and DEB exert different modulation patterns of catalase and manganese superoxide dismutase (MnSOD) activities, and DEB- but not MMC-associated glutathione (GSH) depletion.
The interest in MMC and DEB action mechanisms is strictly related to the Fanconi's anaemia (FA) phenotype, due to the specific sensitivity of FA cells to these agents (2). A broad consensus in FA research refers to the phenotypic feature of FA cell sensitivity to `cross-linking agents' based on the end products of MMC and DEB, which consist of mono- and biadducts to DNA. However, the recent report by Rutherford et al. (3) provides evidence that (i) FA cells fail to accumulate higher MMC adduct levels in DNA than control cells and (ii) the ratio of biadducts to monoadducts (reflective of a DNA repair defect) shows no difference in FA cells compared with normal cells. A previous study from the same laboratory (4) had shown that MMC-induced apoptosis in FA-C cells was exerted in normoxic conditions (associated with redox-cycling mechanisms), whereas MMC was ineffective in causing apoptosis under hypoxic conditions (with prevailing cross-link formation).
In brief, one should recognise that (i) redox-dependent mechanisms are well established for MMC (5–7); (ii) DEB is involved in the impairment of GSH-related detoxification (8); and (iii) both MMC and DEB have oxygen-dependent toxicities, that can be counteracted by a number of antioxidants (1,9,10). These action mechanisms of MMC and DEB are also consistent with an extensive body of evidence relating FA phenotype to excess oxygen sensitivity (11), and accumulation of oxidative DNA damage (12,13).
Whether the formation of DNA interstrand cross-links plays a role in FA remains an open question. FA phenotype and pathogenesis may involve complex and multiple events, possibly including cascade impairments of several detoxification pathways, inter alia DNA repair function(s), as reported recently by Lackinger et al. (14) for defective repair of oxidative DNA damage. The above reported studies of MMC toxicity versus O2-dependent cross-link formation would lead us to deny (or minimize) the relevance of DNA cross-linking as an action mechanism for MMC in FA cells (3,4). However, further investigations on this subject are warranted, both to corroborate these data on MMC action mechanisms, and to ascertain any analogous mechanisms for DEB, which are broadly unknown.
FANCC protein functions and oxidative stress
An involvement of cytochrome P450 (CYP) enzymes in chromosomal instability of FA primary fibroblasts had been suggested by the significant decrease of DEB-induced micronuclei formation in experiments with specific CYP inhibitors (15). It had been demonstrated that FANCC interacts with NADPH CYP reductase (RED) resulting in a decreased RED activity (16). The FANCC–RED complex formation leads to the attenuation of electron transport in the microsomal membrane and, thus, regulates a major cellular detoxification pathway (16). Since RED is involved in the CYP redox activation of a number of xenobiotics, this interaction could suggest a role for FANCC in regulating oxidative pathways. A recent study from the same group reported on the induction of MMC sensitivity in RED-overexpressing HeLa cells (17). In turn, these cells became MMC insensitive when transfected to overexpress FANCC (but neither FANCA nor FANCG), consistent with a specific interaction between FANCC and RED (17).
Another recent study (18) identified a 25 kDa protein binding to FANCC as glutathione S-transferase (GST; GSTP1). FANCC significantly increased GSTP1 catalytic activity, and this effect was counteracted by buthionine sulfoximine-induced inhibition of GSH synthesis. GST is known as a main enzyme for intracellular detoxification of toxic and carcinogenic substances and a part of the inducible pathway for antioxidant defence (19–21). Thus, the available information shows at least a 2-fold interaction of FANCC with enzymes either involved in Phase I or Phase II of mutagen/carcinogen biotransformation (22). Since this process is coupled with a number of redox reactions, the phenotypic abnormalities of FA cells in coping with oxidative stress may find a possible explanation based on the present data. The above interactions of FANCC with RED and GSTT can explain, at least partially, the specific sensitivity of FA cells to MMC (requiring Phase-I enzymes for bioactivation) (23,24) and to DEB (detoxified by GST and a GSH depletor) (1,8).
Conclusion
The available information on MMC and DEB action mechanisms supports the statement of a major, if not exclusive involvement of redox reactions in bioactivation and detoxification of these two agents. A DNA cross-linking mechanism, though consistent with the end-products of MMC and DEB bioactivation, does not appear relevant in the normoxic conditions utilised in testing FA cell sensitivity to MMC and DEB. As a reflection of the effectiveness of redox-mediated mechanisms, the phenotypic defect of FA should be rather recognised as redox imbalance, or reactive oxygen species (ROS) sensitivity.
The recent developments in the field of FANCC functions support the view of a primary defect in controlling ROS formation and detoxification.
Acknowledgments
The Italian Association for Fanconi's Anaemia Research (AIRFA) supported most of the activities of the author in this field.
References
-
Korkina,L.G., Deeva,I.B., De Biase,A., Iaccarino,M., Oral,R., Warnau,M. and Pagano,G. (2000) Redox-dependent toxicity of diepoxybutane and mitomycin C in sea urchin embryogenesis. Carcinogenesis, 21, 213–220.
[Abstract/Free Full Text] -
Ishida,R. and Buchwald,M. (1982) Susceptibility of Fanconi's anemia lymphoblasts to DNA-cross-linking and alkylating agents. Cancer Res., 42, 4000–4006.
[Abstract/Free Full Text] - Rutherford,T.R., Clarke,A.A., Hewer,A., Jenner,A., Phillips,D.H., Gordon-Smith,E.C. and Halliwell,B. (999) DNA adduct formation, oxidative damage and apoptosis in Fanconi anemia cells. Proc. 11th Ann. Int. Fanconi Anemia Scient. Symp., p. 68 (abstract).
- Clarke,A.A., Philpott,N.J., Gordon-Smith,E.C. and Rutherford,T.R. (1997) The sensitivity of Fanconi anaemia group C cells to apoptosis induced by mitomycin C is due to oxygen radical generation, not DNA crosslinking. Br. J. Haematol., 96, 240–247.[Web of Science][Medline]
- Gutteridge,J.M.C., Quinlan,G.J. and Wilkins,S. (1984) Mitomycin C-induced deoxyribose degradation inhibited by superoxide dismutase. A reaction involving iron, hydroxyl and semiquinone radicals. FEBS Lett., 167, 37–41.[Web of Science][Medline]
-
Dusre,L., Rajagopalan,S., Eliot,H.M., Covey,J.M. and Sinha,B.K. (1990) DNA interstrand cross-link and free radical formation in a human multidrug resistant cell line from mitomycin C and its analogues. Cancer Res., 50, 648–652.
[Abstract/Free Full Text] -
Belcourt,M.F., Hodnick,W.F., Rockwell,S. and Sartorelli,A.C. (1996) Differential toxicity of mitomycin C and porfiromycin to aerobic and hypoxic Chinese hamster ovary cells overexpressing human NADPH:cytochrome c (P-450) reductase. Proc. Natl Acad. Sci. USA, 93, 456–460.
[Abstract/Free Full Text] -
Vlachodimitropoulos,D., Norppa,H., Autio,K., Catalan,J., Hirvonen,A., Tasa,G., Uuskula,M., Demopoulos,N.A. and Sorsa,M. (1997) GSTT1-dependent induction of centromere-negative and -positive micronuclei by 1,2:3,4-diepoxybutane in cultured human lymphocytes. Mutagenesis, 12, 397–403.
[Abstract/Free Full Text] - Pagano,G., Korkina,L.G., Brunk,U.T., Chessa,L., Degan,P., Del Principe,D., Kelly,F.J., Malorni,W., Pallardó,F., Pasquier,C., Scovassi,I., Zatterale,A. and Franceschi,C. (1998) Congenital disorders sharing oxidative stress and cancer proneness as phenotypic hallmarks: Prospects for joint research in pharmacology. Med. Hyp., 51, 253–266.[Web of Science][Medline]
- Ruppitsch,W., Meisslitzer,C., Hirsch-Kauffmann,M. and Schweiger,M. (1998) Overexpression of thioredoxin in Fanconi anemia fibroblasts prevents the cytotoxic and DNA damaging effect of mitomycin C and diepoxybutane. FEBS Lett., 422, 99–102.[Web of Science][Medline]
- Poot,M., Gross,O., Epe,B., Pflaum,M. and Hoehn,H. (1996) Cell cycle defect in connection with oxygen and iron sensitivity in Fanconi anemia lymphoblastoid cells. Exp. Cell Res., 222, 262–268.[Web of Science][Medline]
-
Takeuchi,T. and Morimoto,K. (1993) Increased formation of 8-hydroxydeoxyguanosine, an oxidative DNA damage, in lymphoblasts from Fanconi's anemia patients due to possible catalase deficiency. Carcinogenesis, 14, 1115–1120.
[Abstract/Free Full Text] -
Degan,P., Bonassi,S., De Caterina,M., Korkina,L.G., Pinto,L., Scopacasa,F., Zatterale,A., Calzone,R. and Pagano,G. (1995) In vivo accumulation of 8-hydroxy-2'-deoxyguanosine in DNA correlates with release of reactive oxygen species in Fanconi's anaemia families. Carcinogenesis, 16, 735–742.
[Abstract/Free Full Text] - Lackinger,D., Ruppitsch,W., Ramirez,M.H., Hirsch-Kauffmann,M. and Schweiger,M. (1998) Involvement of the Fanconi anemia protein FA-C in repair processes of oxidative DNA damages. FEBS Lett., 440, 103–106.[Web of Science][Medline]
- Ruppitsch,W., Meisslitzer,C., Weirich-Schwaiger,H., Klocker,H., Scheidereit,C., Schweiger,M. and Hirsch-Kauffmann,M. (1997) The role of oxygen metabolism for the pathological phenotype of Fanconi anemia. Hum. Genet., 99, 710–719.[Web of Science][Medline]
-
Kruyt,F.A., Hoshino,T., Liu,J.M., Joseph,P., Jaiswal,A.K. and Youssoufian,H. (1998) Abnormal microsomal detoxification implicated in Fanconi anemia group C by interaction of the FAC protein with NADPH cytochrome P-450 reductase. Blood, 92, 3050–3056.
[Abstract/Free Full Text] - Youssoufian,H. (1999) Progress on the role of p-450 reductase in the pathogenesis of Fanconi anemia and on protein replacement strategies. Proc. 11th Ann. Int. Fanconi Anemia Scient. Symp., p. 54 (abstract).
- Cumming,R.C., Lightfoot,J., Youssoufian,H. and Buchwald,M. (1999) The FANCC protein interacts with GSTP1 to suppress apoptosis in a factor-dependent hematopoietic cell line. Proc. 11th Ann. Int. Fanconi Anemia Scient. Symp., p. 19 (abstract).
- Sen,C.K. and Packer,L. (1996) Antioxidant and redox regulation of gene transcription. FASEB J., 10, 709–720.[Abstract]
- Jefcoate,C.R. (1983) Integration of xenobiotic metabolism in carcinogen activation and detoxication. In Caldwell,J. and Jakoby,W.B. (eds) Biological Basis of Detoxication. Academic Press, New York, NY, pp. 31–76.
- Pinkus,R., Weiner,L.M. and Daniel,V. (1995) Role of quinone-mediated generation of hydroxyl radicals in the induction of glutathione S-transferase gene expression. Biochemistry, 34, 81–88.[Medline]
- Thompson,T.N., Watkins,J.B., Gregus,Z. and Klaasen,C.B. (1982) Effect of microsomal enzyme inducers on the soluble enzymes of hepatic phase II biotransformation. Toxicol. Appl. Pharmacol., 66, 400–408.[Web of Science][Medline]
- Dusre,L., Covey,J.M., Collins,C. and Sinha,B.K. (1989) DNA damage, cytotoxicity and free radical formation by mitomycin C in human cells. Chem. Biol. Interact., 71, 63–78.[Web of Science][Medline]
-
Bligh,H.F.J., Bartoszek,A., Robson,C.N., Hickson,I.D., Kasper,C.B., Beggs,J.D. and Wolf,C.R. (1990) Activation of mitomycin C by NADPH:cytochrome P-450 reductase. Cancer Res., 50, 7789–7792.
[Abstract/Free Full Text]
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