pERK Expression in Skin Squamous and Basal Cell Carcinoma

ObjectiveCurcumin, a naturally occurring bioactive food compound has been shown to inhibit progression of cutaneous SCCa, possibly via inhibition of the MEK/ERK signaling pathway. In our effort to selectively inhibit cutaneous SCCa, we hypothesize that the MEK/ERK pathway is over‐expressed in SCCa, suggesting a novel target for curcumin.MethodNormal human skin (N = 28), BCCa (N = 12), and SCCa (N = 11) were analyzed for pERK (Thr202/Tyr204) expression by IHC. Tumor sections were subjectively scored from 0 to 2+ (none, weak or focal, strong) based on the intensity of the stain, and compared by Chi Square analysis.ResultsAll SCCa (N = 11) and only 5/12 (54%) BCC stained positive for pERK. Tumors expressed more pERK than normal skin χ2 (2, N = 51) = 26.37, P <. 001, and differed by tumor type, χ2 (1, N = 23) = 6.77, P =. 009. Tumor type significantly predicted pERK staining, b =. 67, t(20) = 2.39, P =. 027, and explained a significant proportion of variance in pERK scores, R2 =. 33, F(3, 20) = 3.33, P =. 04, whereas age (P =. 59) and gender (P =. 17) did not explain the variance in pERK staining.ConclusionThe MEK/ERK pathway appears to be over‐expressed in SCCa compared with the more common BCCa. As curcumin has been shown to slow progression of cutaneous SCCa and inhibit pERK expression, the MEK/ERK pathway may prove a key biomarker in developing pharmaceutical agents that prevent SCCa tumor growth.