Detection of IKK epsilon by immunohistochemistry in primary breast cancer: association with EGFR expression and absence of lymph node metastasis

作者：Williams Virginie; Grosset Andree Anne; Cuervo Natalia Zamorano; St Pierre Yves; Sylvestre Marie Pierre; Gaboury Louis; Grandvaux Nathalie^*

来源：BMC Cancer, 2017, 17(1): 356.

DOI：10.1186/s12885-017-3321-6

• IKK epsilon
• Breast
• Cancer
• EGFR
• Metastasis
• Immunohistochemistry
• Biomarker
• Prognosis

Background: IKK epsilon is an oncogenic kinase that was found amplified and overexpressed in a substantial percentage of human breast cancer cell lines and primary tumors using genomic and gene expression analyses. Molecular studies have provided the rational for a key implication of IKK epsilon in breast cancer cells proliferation and invasiveness through the phosphorylation of several substrates.
Methods: Here, we performed immunohistochemical detection of IKK epsilon expression on tissue microarrays constituted of 154 characterized human breast cancer tumors. We further determined the association with multiple clinicopathological parameters and 5-years overall, disease-free and distant disease free survival.
Results: We observed expression of IKK epsilon in 60.4% of the breast cancer tumors. IKK epsilon expression status showed no association with a panel of markers used for molecular classification of the tumors, including ER/PR/HER2 status, or with the molecular subtypes. However, IKK epsilon expression was inversely associated with lymph node metastasis status (p = 0.0032). Additionally, we identified a novel association between IKK epsilon and EGFR expression (p = 0.0011).
Conclusions: The unexpected observation of an inverse association between IKK epsilon and lymph node metastasis advocates for larger scale immunohistochemical profiling of primary breast tumors to clarify the role of IKK epsilon in metastasis. This study suggests that breast cancer tumors expressing EGFR and IKK epsilon may be potential targets for drugs aiming at inhibiting IKK epsilon activity or expression.

• 出版日期2017-5-22