Abstract: Objective To study the expression of double-stranded RNA-dependent protein kinase (PKR) in malignant melanoma and ordinary nevi. Methods The expression of PKR and proliferating cell nuclear antigen was examined in 42 cases of malignant melanoma and 25 ordinary nevi by an immunohistochemical method. Results The positive rate of PKR expression was higher in the patients with malignant melanoma than that in the patients with ordinary nevi (P<0.001). In malignant melanoma, the expression of PKR inversely correlated with that of proliferating cell nuclear antigen (r=-0.442, P<0.001). The expression of PKR was unrelated to the clinical features in malignant melanoma. Conclusion PKR may play an important role in the cellular proliferation of malignant melanoma.

Key words: Melanoma, Nevus, eIF-2 kinase, Proliferating cell nuclear antigen