Carcinogenesis lesion development

Some information on structure-promotion relationships for PBBs is available from studies that used two-stage liver and skin carcinogenesis models. In the liver promotion studies, development of enzyme-altered hepatic foci (putative preneoplastic lesions) was assessed in rats that were partially hepatectomized, initiated with diethylnitrosamine and promoted with PBBs (Buchmann et al. 1991 Dixon et al. 1988 ... 

Simile, MM., Saviozzi, M., De Miglio, M.R., Muroni, M.R., Nufris, A., Pascale, R.M., MalvaltU, G., Feo, F. Persistent chemopreventive effect of S-adenosyl-L-methionine on the development of liver putative preneoplastic lesions induced by thiobenzamide in diethylnitrosamine-initiated rats. Carcinogenesis 1996, 17 1533-1537... 

Cancers with a high frequency of CpG transitions include colorectal cancer (45%), adenocarcinoma of the esophagus (48%) and stomach (34%), tumors of the brain (35%) and uterus (35%), and some hematopoietic malignancies (e.g., Burkitt s lymphoma (32%) (Fig. 3B). In colorectal carcinogenesis, p53 mutation is typically a relatively late event that correlates with the acquisition of an invasive potential (Fearon and Vogelstein, 1990). Acquisition of a CpG mutation in this context may be a consequence of deregulated cell proliferation, DNA instability, or altered nitric oxide metabolism. In the development of adenocarcinoma of the esophagus, however, mutations are often detectable in the preneoplastic lesion, Barrett s mucosa (Montesano et al., 1996). In the latter case, it has been speculated that... 

Zerban, H., R. Preussmann, and P. Bannasch Dosetime relationship of the development of preneoplas-tic fiver lesions induced in rats with low doses of A-nitrosodiethanolamine Carcinogenesis 9 (1988) 607-610. 

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