Activation of the extracellular signal-regulated kinases signaling pathway in squamous cell carcinoma of the skin

culture. In this study, p-ERK 1/2 positive staining was observed in all cases of SCC examined but rarely in the control specimens of normal skin. Moreover, the expression of p-ERK1/2 was significantly higher in poorly differentiated SCC in comparison to well-differentiated ones. Expression levels were positively associated with the degree of malignancy and proliferative activity of SCC. In contrast, inhibition of ERK pathway signaling markedly suppressed tumor cell proliferation. These results suggest that ERK1/2 signal pathways play an important role in the proliferation of SCC and that the inhibition of this signal pathway may be effective in the treatment of cutaneous SCC.