Abdel-Latif Mohamed M M, Kelleher Dermot, Reynolds John V
Department of Clinical Pharmacy, Faculty of Pharmacy, Assiut University, Assiut, Egypt; Department of Surgery, Trinity Centre for Health Sciences, St. James's Hospital, Dublin 8, Ireland.
Department of Clinical Medicine, Trinity Centre for Health Sciences, St. James's Hospital, Dublin 8, Ireland.
Eur J Cancer. 2015 Mar;51(4):464-472. doi: 10.1016/j.ejca.2014.11.014. Epub 2015 Jan 14.
Nuclear factor-kappaB (NF-κB) regulates the expression of a large number of genes involved in the immune and inflammatory response. NF-κB is constitutively activated in oesophageal tumour tissues and induced in oesophageal cells by bile and acid. The aim of the present study was to define the mechanisms underlying NF-κB activation in oesophageal adenocarcinoma.
Fresh biopsy specimens were obtained from 20 patients with oesophageal adenocarcinoma. The activation of NF-κB in oesophageal tumour specimens and oesophageal SKGT-4 cells was assessed by gel mobility shift and Western blotting. Phosphorylation of protein kinase B (AKT/PKB), Ikappa kinase-alpha/beta (IKK-α/β) and extracellular signal-regulated kinase 1/2 (ERK1/2) was examined by Western blotting. High content analysis was used to quantify NF-κB translocation in oesophageal cells.
Oesophageal tumour tissues had higher levels of NF-κB. Increased levels of phosphorylated AKT and IKK-α/β and ERK1/2 were detected in tumour tissues compared with normal oesophageal mucosa. Exposure of SKGT-4 cells to deoxycholic acid (DCA) or acid resulted in NF-κB activation and phosphorylation of AKT, IKK-α/β and ERK1/2. Specific inhibitors for phosphoinositide 3-kinase; PI3K (LY294002 and worhmannin) and ERK1/2 inhibitors (PD98059 and U0126) suppressed DCA- and acid-induced NF-κB activation. The proteasome inhibitor MG-132 and the antioxidants vitamin C and pyrrolidine dithiocarbamate (PDTC) also inhibited NF-κB activation.
Our data demonstrate a major role for PI3K/AKT-IKK-α/β-ERK1/2 signalling pathway in NF-κB activation in oesophageal adenocarcinoma. These results suggest that NF-κB may be a prognostic marker for oesophageal adenocarcinoma, and modulating of NF-κB may uncover new therapeutic strategies.
核因子-κB（NF-κB）调节大量参与免疫和炎症反应的基因的表达。NF-κB在食管肿瘤组织中持续激活，并由胆汁和酸在食管细胞中诱导激活。本研究的目的是确定食管腺癌中NF-κB激活的潜在机制。
从20例食管腺癌患者中获取新鲜活检标本。通过凝胶迁移率变动分析和蛋白质印迹法评估食管肿瘤标本和食管SKGT-4细胞中NF-κB的激活情况。通过蛋白质印迹法检测蛋白激酶B（AKT/PKB）、IκB激酶α/β（IKK-α/β）和细胞外信号调节激酶1/2（ERK1/2）的磷酸化。采用高内涵分析法定量食管细胞中NF-κB的易位。
食管肿瘤组织中NF-κB水平较高。与正常食管黏膜相比，肿瘤组织中磷酸化AKT、IKK-α/β和ERK1/2的水平升高。将SKGT-4细胞暴露于脱氧胆酸（DCA）或酸中会导致NF-κB激活以及AKT、IKK-α/β和ERK1/2的磷酸化。磷酸肌醇3激酶（PI3K）的特异性抑制剂（LY294002和渥曼青霉素）和ERK1/2抑制剂（PD98059和U0126）可抑制DCA和酸诱导的NF-κB激活。蛋白酶体抑制剂MG-132以及抗氧化剂维生素C和吡咯烷二硫代氨基甲酸盐（PDTC）也可抑制NF-κB激活。
我们的数据表明PI3K/AKT-IKK-α/β-ERK1/2信号通路在食管腺癌NF-κB激活中起主要作用。这些结果表明NF-κB可能是食管腺癌的一个预后标志物，调节NF-κB可能会发现新的治疗策略。
