PUMA expression is significantly reduced in human cutaneous melanomas.
Cutaneous malignant melanoma is an aggressive form of skin cancer, characterized by strong chemoresistance and poor patient prognosis. The molecular mechanisms underlying its resistance to chemotherapy remain unclear but are speculated to involve the dysregulation of apoptotic pathways. In this study, we sought to determine whether PUMA (p53 upregulated modulator of apoptosis) contributes to human melanoma formation, tumor progression, and survival. We used tissue microarray and immunohistochemistry to examine PUMA expression in 107 primary melanomas, 51 metastatic melanomas, and 64 dysplastic nevi. Here we report that PUMA expression is significantly weaker in primary melanomas compared to dysplastic nevi (P<0.0001), and is further reduced in metastatic melanomas compared to primary tumors (P=0.001). We show that weak PUMA expression in melanoma correlates with poorer overall and disease-specific 5-year survival (P<0.005 and P<0.001, respectively) of melanoma patients and that PUMA expression in tumor tissue is an independent predictor of both overall and disease-specific 5-year survival (P=0.05). Additionally, we show that exogenous PUMA expression in human melanoma cell lines (both wild type and mutant p53) results in significant apoptotic cell death. Our results suggest that PUMA expression may be an important prognostic marker for human melanoma and that adenoviral delivery of PUMA sensitizes melanoma cells to apoptosis.
Karst
Alison M
AM
Department of Medicine, Division of Dermatology, University of British Columbia, Vancouver, BC V6H 3Z6, Canada.
Dai
Derek L
DL
Martinka
Magdalena
M
Li
Gang
G
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D014408:Biomarkers, Tumor; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008545:Melanoma / Q000235:genetics* / Q000473:pathology*; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D011379:Prognosis; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D012878:Skin Neoplasms / Q000235:genetics* / Q000473:pathology*; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis*
D051017:Apoptosis Regulatory Proteins; C438378:BBC3 protein, human; D014408:Biomarkers, Tumor; D011518:Proto-Oncogene Proteins; D016159:Tumor Suppressor Protein p53