Correlation of RANKL, IKKalpha/beta and Maspin Expression with FOXP3 Regulatory T-Cells in Immunophenotypes of Breast Carcinoma
Gloria Peiro, Fernando Ortiz-Martinez, Ariadna Perez-Balaguer, Pascual Martinez-Peinado, Jose Ponce, F Ignacio Aranda, Enrique Lerma, Jose Sanchez-Paya, Jose M Sempere-Ortells. University General Hospital, Alicante, Spain; University of Alicante, Alicante, Spain; Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
Background: RANKL, the receptor activator of NFkB (RANK/TNFRSF11A) ligand, has been reported to activate IKKalpha (kappaB kinase inhibitor alpha), which in turn controls Maspin expression. On the other hand, IKKbeta is a key regulator of FOXP3 expression during development of natural regulatory T-cells (Tregs). Recent studies suggest their role in the pathogenesis of cancer and metastasis. In this study we evaluated the FOXP3+ Tregs content in tumor microenvironment of breast carcinoma (BC) and correlated the results with RANKL, IKKalpha/beta and Maspin expression; and patient's outcome.
Design: We performed an immunohistochemical (IHC) study of FOXP3, RANKL, phospho-(p)-IKKalpha/beta and Maspin on paraffin-embedded tissue microarrays (1mm cores) containing 245 BC, stratified by immunophenotypes: 39% Luminal A/B (ER/PR+, HER2-), 40% HER2+ (>30% cells 3+ by IHC and/or FISH/CISH amplification), and 21% TN/basal-like (ER/PR/HER2- +/-CK5/6+/-EGFR+). FOXP3+ Tregs within the tumor and/or immediately adjacent stroma were counted in 3 high power fields (x400). Cytoplasm or nuclear staining were semiquantitatively scored based on intensity and distribution (0-300). IHC results, clinicopathological factors and outcome were correlated.
Results: Median patients' age was 50 years (range 20-85 years) and median follow-up 99 months (range 6-302 months). High number of Tregs (median threshold >15 FOXP3+ cells) (22%) correlated positively with tumors presented at younger ages (31%), of grade 3 (33%) with necrosis (40%) and overexpression of RANKL (38%) and nuclear or cytoplasmic Maspin (34% and 30%; respectively); and negatively with p-IKKalpha/beta (38%) (all p<0.05). TN/basal-like tumors showed increased Tregs (39%), and overexpressed RANKL (43%) and Maspin (43% nuclear and 51% cytoplasm), but Luminal tumors overexpressed p-IKKalpha/beta (72%) (p=0.001). Overall survival was better for patients whose tumors overexpressed RANKL (94%; p=0.01) or p-IKKalpha/beta (86%; p=0.05). However, neither Tregs content nor Maspin subcellular location showed prognostic significance (p=ns) (Kaplan-Meier; log rank test).
Conclusions: We demonstrated a correlation of FOXP3+ Tregs with RANKL and Maspin expression that were specifically increased in TN/basal-like tumors, supporting their role as markers of aggressive BC. However, IKKalpha/beta was detected in Luminal phenotypes. Nevertheless, only RANKL and IKKalpha/beta correlated with outcome.
Supported by Grants FIS 10/00082, AP-172/10, FCVI-HGUA (2010/PC-04 and 2011/PC-03).
Tuesday, March 5, 2013 1:00 PM
Poster Session IV # 35, Tuesday Afternoon