Automated Quantitative Analysis of Activator Protein-2α Subcellular Expression in Melanoma Tissue Microarrays Correlates with Survival Prediction

Aaron J. Berger, Darren W. Davis, Carmen Tellez, Victor G. Prieto, Jeffrey E. Gershenwald, Marcella M. Johnson, David L. Rimm, Menashe Bar-Eli
2005 Cancer Research  
The activator protein-2A (AP-2) transcription factor plays a key role in regulating expression of genes involved in tumor growth and metastasis of human melanoma. We sought to assess the prognostic significance of AP-2 expression and its role in the transition of nevi to metastatic melanoma. Two cohorts were analyzed. One was a "progression" microarray containing melanoma specimens from M.D. Anderson Cancer Center representing 84 cases and the other was a retrospective cohort from Yale
more » ... y representing 214 primary melanomas and 293 metastases. Analysis of total AP-2 expression using two quantitative systems [automated quantitative analysis (AQUA) and laser scanning cytometry (LSC)] revealed no correlation with diagnosis group. LSC analysis of the M.D. Anderson Cancer Center array showed that the number of cells expressing nuclear AP-2 was highest in the benign nevi group (11.85%) and significantly decreased in each phase of melanoma progression to 0.39% in the metastatic group. Both LSC and AQUA showed decreased nuclear AP-2 levels and increased cytoplasmic AP-2 that is directly proportional to progression. Neither nuclear nor cytoplasmic expression levels correlated with outcome. Intriguingly, the ratio of cytoplasmic to nuclear AP-2 predicted outcome in the entire population and in the primary tumors alone, demonstrating the power of the ratio to normalize for variations. Furthermore, the AP-2 ratio directly correlated with other clinicopathologic factors, including Breslow depth (R = 0.334, P < 0.001). We show that a high level of AP-2 expression in the cytoplasm relative to the nucleus correlates with poor prognosis and the loss of nuclear AP-2 expression is associated with malignant transformation and progression of melanoma. (Cancer Res 2005; 65(23): 11185-92)
doi:10.1158/0008-5472.can-05-2300 pmid:16322269 fatcat:l4khccycljh2nagcbe3k6ia7va