Expression of activated Akt and PTEN in malignant melanomas: relationship with clinical outcome

Abstract

Our purpose was to analyze, by immunohisto-chemistry, the expression of activated serine-threonine protein kinase B (p-Akt) and phosphatase and tensin homologue deleted on chromosome 10 (PTEN) in benign nevi and primary and metastatic melanomas and to correlate the expression level with clinical variables. We observed cytoplasmic and/or nuclear expression of p-Akt in 22 (54%) of 41 benign nevi, 112 (71.3%) of 157 primary tumors, and 50 (71%) of 70 metastases. Cytoplasmic PTEN staining was observed in 0 (0%), 152 (87.7%), and 64 (90%) of 41 nevi, 162 primary tumors, and 71 metastases, respectively. A significant positive correlation was seen between PTEN and p-Akt cytoplasmic expression (P < .001) in primary melanomas. Cytoplasmic p-Akt expression showed a positive association with cyclin A in superficial spreading (P = .038) but not in nodular (P = .22) melanomas. Cytoplasmic p-Akt and PTEN expression did not have an impact on disease-free and overall survival, but complete lack of nuclear p-Akt expression was a predictor of shorter disease-free survival (P = .025) for patients with superficial spreading melanoma.