Washington, July 15: Researchers at the University of Minnesota have confirmed that an enzyme known as JNK2 plays a pivotal role in the development of nonmelanoma skin cancers, thus suggesting that JNK2 should be considered as a target for the prevention and treatment of such cancers.
The process of cancer development involves a chain of interactions among bio-chemicals in the skin, and bio-chemicals that play key roles in carcinogenesis make potential therapeutic targets.


Many human cancers show elevated activity in some form of JNK enzyme, and the enzyme is also activated by sunlight, said Lead author Zigang Dong, director of the university`s Hormel Institute in Austin, Minnesota, while presenting his work at the American Association for Cancer Research meeting in the Washington Convention Centre.

"Even if one goes into the sun for a few minutes, the activity of JNK in the epidermis rises," said Dong. "If you go out for a few minutes, JNK activity doesn`t stay elevated. But it looks as though if a person gets too much sun exposure, JNK activity becomes permanently elevated and cancers develop. This study indicates that some form of JNK activity is a key step in the process by which nonmelanoma cancers grow."


Working with mice, Dong and his colleagues focused on two enzymes known to be activated by factors that cause cells to divide and that have been considered important in skin cells` response to UV light. Of the two enzymes, called JNK1 and JNK2, only the latter turned out to play an important role in the development of tumours, the researchers found.


The findings suggest that when JNK2 is lacking, skin cells are inhibited, or at least delayed, in their response to UVB light.

"Knocking out the JNK2 enzyme could simply delay the response to ultraviolet light, but if so, it would be significant," Dong said.