Antioxidants implicated in skin cancer gender difference
MedWire News: Women have higher levels of a natural "antioxidant" substance in their skin than men, study findings suggest.
The discovery could help to explain why rates of skin cancer are up to three times higher in men compared with women, say Dr Gregory Lesinski (Ohio State University, Columbus, USA) and fellow researchers.
Dr Lesinski's group investigated the reasons for the gender discrepancy using mice that were genetically predisposed to developing skin cancer. The team looked specifically at levels of a protein called catalase, which is found in the skin and has "antioxidant" properties.
Antioxidants are substances that protect the body against the effects of free radicals, explain the researchers. Free radicals are produced by the body in response to sunlight (among other factors) and are thought to play a role heart disease, cancer and other diseases.
In the first part of the study, the researchers measured levels of catalase in the animals' skin. They found that male mice had lower levels of catalase than female mice.
The mice were then exposed to ultraviolet B (UVB) radiation, a component of sunlight that causes sunburn and aging.
In both male and female mice, catalase levels fell dramatically after UVB exposure.
In addition, UVB exposure caused certain types of white blood cells to move from the bone marrow to the skin - the first time such an effect has been reported. The movement was more dramatic in male than female mice, and is significant because it could potentially increase susceptibility to diseases - including skin cancer.
Finally, the researchers treated mice with a skin cream containing catalase. This halted the movement of white blood cells to the skin, adding weight to the hypothesis that catalase levels may be involved in the gender discrepancy in skin cancer.
More work is now needed to see if the same pathways are involved in human skin cancers, the team says.
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
By Joanna Lyford