Lower Catalase Level Might Explain Higher Skin-Cancer Rate
Men are three times more likely than women to develop a common form of skin cancer, and a study by researchers at the OSUCCC – James may help explain why. The investigators found that male mice had lower levels of an important skin antioxidant than female mice and higher levels of certain cancer-linked inflammatory cells.
The antioxidant, a protein called catalase, inhibits skin cancer by mopping up hydrogen peroxide and other DNA-damaging reactive-oxygen compounds that form during exposure to ultraviolet B light (UVB), a common source of sunburn and cancer-causing skin damage.
The findings suggest that women may have more natural antioxidant protection in the skin than men, perhaps raising men’s risk of skin cancer, say study co-leaders Gregory Lesinski, PhD, a member of the OSUCCC – James Innate Immunity Program, and Tatiana Oberyszyn, PhD, of the OSUCCC – James Molecular Carcinogenesis and Chemoprevention Program.
The UVB exposure also caused an inflammatory white-blood-cell population called myeloid-derived suppressor cells to migrate from the bone marrow into the exposed skin. Higher numbers of these cells moved into the skin of male mice than female mice.
“These cells might be a novel source of UVB-induced immune suppression,” says first author Nicholas Sullivan, a research scientist in Oberyszyn’s lab. The research suggests that these UVB-induced inflammatory cells contribute to the genesis of skin tumors and perhaps other tumors rather than simply facilitating cancer progression, as generally thought, Sullivan notes.
The researchers conducted the study using a strain of hairless mice that develops squamous cell carcinoma of the skin – the second most common skin cancer in humans – when exposed to UVB.
Published in the journal Cancer Research.