Most skin cancers are highly curable, but require surgery that can be painful and scarring结疤. A new study by Loyola University Health System researchers could lead to alternative treatments that would shrink skin cancer tumors with drugs. The drugs would work by turning on a gene² that prevents skin cells from becoming cancerous, said senior author Mitchell Denning³, Ph.D.

The study was published Jan. 15, 2010 in the Journal of Biological Chemistry.

More than 1 million people in the United States are diagnosed with skin cancer each year. In the new study, researchers examined a type of skin cancer, called squamous cell carcinoma鳞状细胞癌, that accounts for between 200,000 and 300,000 new cases per year.

Squamous cell carcinoma begins in the upper part of the epidermis上皮，表皮, the top layer of the skin. Most cases develop on areas that receive lots of sun, such as the face, ear, neck, lips and backs of hands. There are various surgical⁵ treatments, including simple excision切除, curettage刮除术 and electrodessication (scraping with a surgical tool and treating with an electric needle) and cryosurgery冷冻手术，低温外科 (freezing with liquid nitrogen). Removing large skin cancers can require skin grafts植皮手术 and be disfiguring使变丑.

Sunlight can damage a skin cell's DNA⁸. Normally, a protein called protein kinase C蛋白激酶C (PKC) is activated⁹ in response to the damage. If the damage is too great to repair, the PKC protein directs the cell to die.

Healthy cells grow and divide in a cell-division cycle. At several checkpoints in this cycle, the cell stops to repair damaged DNA before progressing to the next step in the cycle. The new study found that the PKC gene is responsible for stopping the cell at the checkpoint just before the point when the cell divides. In squamous cell carcinoma, the PKC gene is turned off. The cell proceeds to divide without first stopping to repair its DNA, thus producing daughter tumor¹ cells.

Denning said a class of drugs called protein kinase inhibitors potentially could shrink tumors by turning the PKC gene back on. Several such drugs have been approved by the Food and Drug Administration for other cancers. Denning is pursuing grant funding to test such drugs on animal models.