Susceptibility of zucker rats to mammary gland and colon carcinogenesis

grantor: University of TorontoThe objectives were to determine whether the Zucker rat strain is susceptible to breast and colon carcinogenesis, and whether the metabolic abnormalities of obese (fa/fa) rats increase their susceptibility towards carcinogenesis compared to lean (FA/FA or FA/fa) rats. Breast and colon cancer was initiated with 37.5mg/kg MNU at 50 days of age followed by two weekly doses of 15 mg/kg AOM. Lean and obese rats were susceptible to developing both cancers. However, mammary and colon tumor incidence and multiplicity were higher in obese rats than in lean rats. DNA methylation levels showed that obese rats received a higher biologically effective MNU dose than lean rats, although AOM doses were comparable. Therefore, the results suggest that the Zucker rat strain is susceptible to breast and colon cancer. Furthermore, obese rats are more susceptible to colon carcinogenesis than lean rats, although the relative susceptibility of Zucker rats towards breast cancer requires further investigation.M.Sc