The mineral zinc may help prevent oesophageal and oral cancers in people at high risk, suggests research on rats.
A team from the Kimmel Cancer Center of Thomas Jefferson University in Philadelphia found that rats that are deficient in dietary zinc experience increased expression of COX-2 in the oesophagus and tongue, an effect that is accompanied by a hyperplastic phenotype in these areas that is likely relevant to cancer development.
Oesophageal and tongue cancers have previously been associated with dietary zinc deficiency, and these cancers often overexpress COX-2, a characteristic known to contribute to carcinogenesis.
Louise Fong and colleagues report in today's issue of the Journal of the National Cancer Institute (vol 97, no 1, pp40-50) that COX-2 overexpression accompanies hyperplasia in zinc-deficient rats.
Treating the rats with zinc or a COX-2 inhibitor reduced COX-2 overexpression and reversed the hyperplasia found in the oesophagus.