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. 1993 Jan;120(1-2):71–75. doi: 10.1007/BF01200727

Persistent proliferation of normal hepatocytes and promotion of preneoplastic development byN-nitrosodibenzylamine in rats

H Blaszyk 1, A Hartmann 1, M Danz 1,✉
PMCID: PMC12201764  PMID: 8270612

Abstract

In a traditional long-term studyN-nitrosodibenzylamine (NDBzA) was proven to be noncarcinogenic, but recently the substance was found to produce genotoxic lesions in hepatocytes. Our own experiments have shown that relatively low single doses of NDBzA cause liver hypertrophy and additive proliferation of hepatocytes in rats. Both effects are known from well-documented promoters and nongenotoxic carcinogens, respectively, in rodents. Investigation of NDBzA in an initiation-promotion assay (IP assay) showed it to cause an increase in the number and size of preneoplastic liver cell foci. This occurred only after initiation with diethylnitrosamine, but not when 2-acetylaminofluorene was used. Another property of NDBzA is its sustained mitotic stimulation of extrafocal hepatocytes. This is inconsistent with their adaptive loss of susceptibility to mitogens in IP assays using other promoters of hepatocarcinogenesis. The following conclusions can be drawn. First, “differential inhibition” of the proliferation of extrafocal hepatocytes, in contrast to the selective mitostimulation of preneoplastic cells, is obviously no prerequisite for cancer development. Second, primary mitogenicity of a compound in short-term studies can be a useful indicator for tumorigenic potential. In the case of NDBzA the data available at present are still insufficient to classify it unequivocally in terms of genotoxic or nongenotoxic carcinogenicity.

Key words: N-Nitrosodibenzylamine, Hepatocyte mitogen, Initiation-promotion assay, Promotion activity, Sustained extrafocal mitogenicity

Abbreviations

2-AAF

2-acetylaminofluorene

DEN

diethylnitrosamine

DMSO

dimenthylsulfoxide

IP assay

initiation-promotion assay

NDBzA

N-nitrosodibenzylamine

MI

mitotic index

References

  1. Appel KE, Gersdorf S, Menden M, Lauterbach M (1990) DNA damage induced byN-nitrosodibenzylamine andN-nitroso-alpha-acetoxybenzyl-benzylamine in mammalian cell systems and in vivo. Toxicol Lett 52:269–277 [DOI] [PubMed] [Google Scholar]
  2. Ashby J, Tennant RW (1991) Definitive relationships among chemical structure, carcinogenicity and mutagenicity for 301 chemicals tested by the U.S. NTP. Mutat Res 257:229–306 [DOI] [PubMed] [Google Scholar]
  3. Ashby J, Lefevre PA (1992) Mitogenesis, micronuclei, and carcinogenesis in the rat liver — some basic inconsistencies. Environ Mol Mutagen 20:29–38 [DOI] [PubMed] [Google Scholar]
  4. Bannasch P, Enzmann H, Hacker HJ, Weber E, Zerban H (1989) Comparative pathobiology of hepatic preneoplasia. In: Bannasch P, Keppler D, Weber G (eds) Liver cell carcinoma. Falk Symp 51. Kluwer, Dordrecht Boston London, pp 55–76 [Google Scholar]
  5. Boyes BC, Rogers CC, Matula TI, Stapley R, Sen NP (1990) Evaluation of genotoxicity ofN-nitrosodibenzylnitrosamine in Chinese hamster V79 cells and in Salmonella. Mutat Res 241:379–385 [DOI] [PubMed] [Google Scholar]
  6. Butterworth BE (1990) Consideration of both genotoxic and nongenotoxic mechanisms in predicting carcinogenic potential. Mutat Res 239:117–132 [DOI] [PubMed] [Google Scholar]
  7. Cerutti PA (1988) Commentary: response modification creates promotability in multistage carcinogenesis. Carcinogenesis 9:519–526 [DOI] [PubMed] [Google Scholar]
  8. Clayson DB (1989) Can a mechanistic rationale be provided for nongenotoxic carcinogens identified in rodent bioassays? Mutat Res 221:53–67 [DOI] [PubMed] [Google Scholar]
  9. Danz M, Urban H, Schmidt A, Ziebarth D (1978) A possible short-term prediction of potential carcinogenicity of chemical compounds in vivo by means of a promoting activity test (PAT). Exp Pathol 16:109–120 [DOI] [PubMed] [Google Scholar]
  10. Druckrey H, Preussmann R, Ivankovic S, Schmähl D (1967) Organotrope carcinogene Wirkungen bei 65 verschiedenenN-Nitroso-Verbindungen an BD Ratten. Z Krebsforsch 69:103–201 [PubMed] [Google Scholar]
  11. Farber E, Chen Z-Y, Harris L, Lee G, Rinaudo JS, Roomi WM, Rotstein J, Semple E (1989) The biochemical-molecular pathology of the stepwise development of liver cancer: new insights and problems. In: Bannasch P, Keppler D, Weber G (eds) Liver cell carcinoma. Falk Symp 51. Kluwer, Dordrecht Boston London, pp 273–291 [Google Scholar]
  12. Goldsworthy T, Campbell HA, Pitot HC (1984) The natural history and dose-response characteristics of enzyme-altered foci in rat liver following phenobarbital and diethylnitrosamine administration. Carcinogenesis 5:67–71 [DOI] [PubMed] [Google Scholar]
  13. Ito N, Tatematsu M, Nakanishi K, Tsuda H (1982) Analysis of the effects of promoting agents on liver and urinary bladder carcinogenesis in rats. In: Hecker E et al. (eds) Carcinogenesis. A comprehensive survey, vol 7. Raven Press, New York, pp 133–137 [PubMed] [Google Scholar]
  14. Ito N, Imaida K, DeCamargo JLV, Takahashi S, Asamoto M, Tsuda H (1988) A medium-term bioassay system for detection of environmental carcinogens using diethylnitrosamine-initiated rat liver followed byd-galactosamine treatment and partial hepatectomy. Jpn J Cancer Res (Gann) 79:573–575 [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Jacobson MK, Baron RA, Yoder SS, Sieg S, Lyle TE (1979) Mutagenicity of the noncarcinogenic dibenzylnitrosamine and an alphaacetoxy-derivate. Cancer Lett 6:83–97 [DOI] [PubMed] [Google Scholar]
  16. Klopman G, Frierson MR, Rosenkranz HS (1990) The structural basis of the mutagenicity of chemicals in the Salmonella typhimurium: the Gen-Tox Data Base. Mutat Res 228:1–50 [DOI] [PubMed] [Google Scholar]
  17. Kunz W, Schaude G, Schwarz M, Tennekes H (1982) Quantitative aspects of drug-mediated tumour promotion in liver and its toxicological implications. In: Hecker E et al. (eds) Carcinogenesis. A comprehensive survey, vol 7. Raven press, New York, pp 111–125 [PubMed] [Google Scholar]
  18. Ledda-Columbano GM, Coni P, Curto M, Giacomini L, Faa C, Sarma DSR, Columbano A (1992) Mitogen-induced liver hyperplasia does not substitute for compensatory regeneration during promotion of chemical hepatocarcinogenesis. Carcinogenesis 13:379–383 [DOI] [PubMed] [Google Scholar]
  19. Loury DJ, Goldsworthy TL, Butterworth BE (1987) The value of measuring cell replication as a predictive index of tissue-specific tumorigenic potential. Banbury 25:119–136 [Google Scholar]
  20. Marsman DS, Cattley RC, Conway JG, Popp JA (1988) Relationship of the peroxisome proliferation and replicative DNA synthesis to the hepatocarcinogenicity of the peroxisome proliferators di(2-ethylhexyl)-phthalate and [4-chloro-6-(2,3-xylidino)-2-pyrimidinylthio] acetic acid (Wy-14,643) in rats. Cancer Res 48:6739–6744 [PubMed] [Google Scholar]
  21. McCann J, Choi E, Yamasaki E, Ames BN (1975) Detection of carcinogens as mutagens in theSalmonella/microsome test: assay of 300 chemicals. Proc Natl Acad Sci USA 72:5135–5139 [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Peraino C, Fry RJM, Staffeldt E, Christopher JP (1975) Comparative enhancing effects of phenobarbital, amobarbital, diphenylhydantoin, and dichlorodiphenylchloroethane on 2-acetylamino-fluorene-induced hepatic tumorigenesis in the rat. Cancer Res 35:2884–2890 [PubMed] [Google Scholar]
  23. Pitot HC, Goldsworthy T, Moran S, Sirica AE, Weeks J (1982) Properties of incomplete carcinogens and promoters in hepatocarcinogenesis. In: Hecker E et al. (eds) Carcinogenesis. A comprehensive survey, vol 7. Raven Press, New York, pp 85–98 [PubMed] [Google Scholar]
  24. Preussmann R, Spiegelhalder B (1989) EnvironmentalN-nitroso carcinogens—problems and solutions. Interdiscip Sci Rev 14:248–253 [Google Scholar]
  25. Ruthenberg AM, Kim H, Fischbein JW, Hanker JS, Wasserkrug HL, Seligman AM (1969) Histochemical and ultrastructural demonstration of γ-glutamyl transpeptidase activity. J Histochem Cytochem 17:517–526 [DOI] [PubMed] [Google Scholar]
  26. Sarma DSR, Rao MR, Rajalakshmi S (1986) Liver tumor promotion by chemicals: models and mechanisms. Cancer Surv 5:781–799 [PubMed] [Google Scholar]
  27. Schmähl D (ed 1981) Maligne Tumoren-Entstehung, Wachstum, Chemotherapie. Editio Cantor, Aulendorf [Google Scholar]
  28. Schmähl D, Schmezer P (1990) Comparison of human and rodent response to genotoxicants. In: Mutation and the environment. Part C. Wiley-Liss, New York, pp 311–320 [PubMed] [Google Scholar]
  29. Schmezer P, Pool BL, Lefevre PA, Callander RD, Rapton F, Tinwell H, Ashby J (1990) Assay-specific genotoxicity of the non-carcinogenN-nitrosodibenzylamine to the rat liver in vivo. Environ. Mol Mutagen 15:190–1971 [DOI] [PubMed] [Google Scholar]
  30. Schulte-Hermann R, Schmitz E (1980) Feed-back inhibition of hepatic DNA synthesis. Cell Tissue Kinet 13:371–380 [DOI] [PubMed] [Google Scholar]
  31. Schulte-Hermann R, Ohde G, Schuppler J, Timmermann-Trosiener I (1981) Enhanced proliferation of putative preneoplastic cells in rat liver following treatment with tumor promoters phenobarbital, hexachlorocyclohexane, steroid compounds and nafenopin. Cancer Res 41:2556–2562 [PubMed] [Google Scholar]
  32. Seglen PO, Gerlyng P (1990) Growth-related alterations during liver carcinogenesis: effect of promoters. Environ Health Perspect 88:197–205 [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Shelby MD, Zeiger E, Tennant RW (1988) Commentary on the status of short-term tests for chemical carcinogens. Environ Mol Mutagen 11:437–441 [DOI] [PubMed] [Google Scholar]
  34. Shirai T, Imaida K, Ohshima M, Fukushima S, Lee M-S, King CM, Ito N (1985) Different responses to phenobarbital promotion in the development of γ-glutamyltranspeptidase-positive foci in the liver of rats initiated with diethylnitrosamine,N-hydroxy-2-acetylamino-fluorene and aflatoxin B1. Jpn J Cancer Res (Gann) 76:16–19 [PubMed] [Google Scholar]
  35. Solt D, Farber E (1976) New principle for the analysis of chemical carcinogenesis. Nature 263:701–703 [Google Scholar]
  36. Takano T, Tatematsu M, Hasegawa R, Imaida K, Ito N (1980) Dose-response relationship for the promoting effect of phenobarbital on the induction of liver hyperplastic nodules in rats exposed to 2-acetyl-aminofluorene and carbon tetrachloride. Gann 71:580–581 [PubMed] [Google Scholar]

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