Decreased expression of Apaf-1 with progression of melanoma.
Defects in apoptotic system may contribute in the pathogenesis and resistance of malignant melanoma cells to chemotherapy. Apoptotic protease-activating factor-1 (Apaf-1) is a cell death effector that acts with cytochrome c and caspase-9 to mediate apoptosis. Recently it was shown that metastatic melanomas often lose Apaf-1 and are concomitantly resistant to apoptosis. It is not known, however, whether Apaf-1 protein is lost during melanoma progression from localized to metastatic tumor. To this end, we evaluated Apaf-1 protein expression by immunohistochemistry in 10 cases of human nevi, 11 melanomas in situ, 26 primary melanomas and 15 metastases. Significant decreases in Apaf-1 expression was observed when comparing nevi and melanomas (chi-square = 33.719; P < 0.0001). Moreover, primary melanomas with greater tumor thickness showed lesser expression of Apaf-1 (chi-square = 16.182; P < 0.003). Intriguingly, we were unable to detect Apaf-1 expression in lesions of metastatic melanomas. These data demonstrated that there is an inverse correlation between Apaf-1 expression and pathologic stage of melanoma. This suggests that the decreased expression of Apaf-1 seen in correlation with melanoma progression renders melanoma more resistant to chemotherapy.
Mustika
Rita
R
Division of Dermatology, Clinical Molecular Medicine, Faculty of Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
Budiyanto
Arief
A
Nishigori
Chikako
C
Ichihashi
Masamitsu
M
Ueda
Masato
M
D053477:Apoptotic Protease-Activating Factor 1; D014408:Biomarkers, Tumor; D018450:Disease Progression; D015536:Down-Regulation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008545:Melanoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D009362:Neoplasm Metastasis; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D012878:Skin Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology
C506592:APAF1 protein, human; D053477:Apoptotic Protease-Activating Factor 1; D014408:Biomarkers, Tumor; D011506:Proteins