by ecancer reporter Janet Fricker

 A mouse study, published in the Journal of Investigative Dermatology , provides an explanation why men are three times more likely than women to develop cutaneous squamous cell carcinoma and twice as likely to develop cutaneous basal cell carcinoma.

Investigators led by Gregory Lesinski, from The Ohio State University Comprehensive Cancer Center (Ohio, USA), found that male mice (from a  strain of hairless mice that develop squamous cell carcinoma of the skin )had lower levels of the anti-oxidant  catalase  present in their skin than female mice .  The significance of catalase is that it inhibits skin cancer by mopping up hydrogen peroxide and other DNA-damaging reactive-oxygen compounds that form during exposure to ultraviolet B light.

Additionally, investigators found that  UVB exposure caused 55%  higher numbers of  'myeloid-derived suppressor cells'  (a unique inflammatory white blood cell population ) to migrate from bone marrow to the exposed skin in male mice than female mice.

 “Our results highlight inherent sex discrepancies in skin catalase activity and percentages of

splenic...myeloid cells in skin tumour-bearing mice,” write the authors.

Men face a higher risk of numerous types of cancers, they add,  and their relatively higher levels of inflammatory myeloid cells may be one of the factors contributing to this susceptibility.

Reference

N J Sullivan, KL Tober, EM Burns, et al. UV Light B-Mediated Inhibition of Skin Catalase Activity Promotes Gr-1þCD11bþ Myeloid Cell Expansion. Journal of Investigative Dermatology.  doi:10.1038/jid.2011.329