Collaboration between growth factors and diverse chemical carcinogens in hepatocarcinogenesis of transforming growth factor α transgenic mice

Hitoshi Takagi, Richard R Sharp, Hisashi Takayama, Miriam R. Anver, Jerrold M. Ward, Glenn Merlino

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48 Scopus citations

Abstract

Transforming growth factor α (TGF-α) has been shown to induce liver tumors within 1 year in transgenic male mice in which this potent mitogen is overexpressed. To determine more precisely how TGF-α participates in multistep tumorigenesis of the liver, genotoxic (diethylnitrosamine or dimethylnitrosamine) and nongenotoxic (phenobarbital) chemical carcinogens were administered independently to TGF-α transgenic mice [line MT42 on a Crl:CD-1(ICR)BR background]. TGF-α overexpression dramatically accelerated carcinogen-induced hepatocarcinogenesis in MT42 males but not females. Interestingly, all three chemical agents were found to enhance strongly both hepatic tumor formation and progression in TGF-α transgenic male mice. In this study 100%, 90%, and 78% of transgenic males exposed to diethylnitrosamine, dimethylnitrosamine or phenobarbital, respectively, developed tumors between 24 and 32 weeks of age. Moreover, approximately 70% of tumor-bearing transgenic mice from each treatment group had hepatocellular carcinomas; no malignant lesions were found in any carcinogen-treated or untreated nontransgenic mice or in untreated MT42 mice at this age. These results demonstrate that chemical agents as diverse as nitrosamines and phenobarbital act as cocarcinogens with TGF-α in the livers of these transgenic mice, indicating that TGF-α possesses the unique ability to complement both initiation and promotion in hepatocarcinogenesis. Furthermore, because carcinogen-induced malignant conversion was restricted to transgenic mice, constitutive TGF-α overexpression may promote liver tumor progression as well.

Original languageEnglish (US)
Pages (from-to)4329-4336
Number of pages8
JournalCancer Research
Volume53
Issue number18
StatePublished - Sep 15 1993

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ASJC Scopus subject areas

  • Cancer Research
  • Oncology

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