Immunohistochemical analysis of NF-κB signaling proteins IKKε, p50/p105, p52/p100 and RelA in prostate cancers
Abstract:Seo SI, Song SY, Kang MR, Kim MS, Oh JE, Kim YR, Lee JY, Yoo NJ, Lee SH. Immunohistochemical analysis of NF-κB signaling proteins IKKε, p50/p105, p52/p100 and RelA in prostate cancers. APMIS 2009; 117:623–8.
Activation of nuclear factor-kappa B (NF-κB) signaling is considered an important mechanism in the development of prostate cancers. A recent study revealed that IκB kinase epsilon (IKKε), an activator of NF-κB, was overexpressed in breast cancers and acted as an oncogene. Expression of NF-κB members has been reported in prostate cancer tissues, but expression of IKKε has not yet been studied in prostate cancers. In this study, we attempted to explore as to whether expressions of IKKε and NF-κB members p50/105, p52/p100 and RelA are altered in prostate cancers. We analyzed the expression of IKKε, p50/105, p52/p100 and RelA in 107 prostate adenocarcinoma tissues by immunohistochemistry using a tissue microarray (TMA) method. In the TMA, IKKε is expressed in basal cells, but not in alveolar cells in normal prostate glands. IKKε is expressed in 60.0% of prostate intraepithelial neoplasm (PIN) and 70.1% of the prostate cancers in the cytoplasm. Nuclear immunostainings of NF-κB members p50/105, p52/p100 and RelA, which are considered activation of NF-κB signaling, were observed respectively in 28.0%, 18.7% and 37.4% of the cancers. Nuclear staining was detected neither in normal alveolar cells nor in PIN. However, none of the expression of p50/105 nor p52/p100 nor RelA nor IKKε was associated with pathologic characteristics, including size of the cancers, age, Gleason score and stage. The increased cytoplasmic expression of IKKε as well as the increased nuclear expressions of p50/105, p52/p100 and RelA in the prostate cancers compared to normal alveolar cells suggested that overexpression of these proteins may be related to activation of the NF-κB pathway and might play a role in tumorigenesis of prostate cancers.
Document Type: Research Article
Affiliations: 1: Urology 2: Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 3: Departments of Pathology 4: Urology, College of Medicine, The Catholic University of Korea, Seoul, Korea
Publication date: August 1, 2009