Cimetidine inhibits epidermal growth factor-induced cell signaling
Cimetidine inhibits epidermal growth factor-induced cell signaling
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DOI：
10.1111/j.1440-1746.2006.04541.x
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发表时间：
2007-03-01
影响因子：
4.1
通讯作者：
Shiratori, Yasushi
中科院分区：
文献类型：
--
作者：
Fujikawa, Tatsuya;Shiraha, Hidenori;Shiratori, Yasushi
背景资料：西咪替丁是一种组胺-2（H-2）受体拮抗剂，已被证明对结直肠癌、黑色素瘤和肾细胞癌具有抗癌作用。方法：以肝癌细胞系Hep 3B、HLF、SK Hep 1、JHH 2、PLC/PRF/5和HLE为研究对象，采用[H 3]-TdR掺入法检测细胞增殖和迁移。通过体外细胞迁移测定来测量细胞迁移。用表达人表皮生长因子受体（EGFR）的小鼠成纤维细胞（NR 6-WT）评估西咪替丁的生物学效应。通过免疫沉淀和免疫印迹分析EGFR的自身磷酸化和其他下游效应物的活化。结果：西咪替丁对EGF诱导的Hep 3B、HLF、SK Hep 1和JHH 2细胞增殖和迁移均有抑制作用，而对PLC/PRF/5和HLE细胞增殖和迁移无影响。西咪替丁被发现破坏表皮生长因子诱导的EGFR及其下游效应物，有丝分裂原活化蛋白激酶和磷脂酶C-γ的自磷酸化。为了确定这种负调节的分子基础，我们确定西咪替丁显著降低细胞内cAMP水平，cAMP的减少抑制EGFR的自磷酸化。cAMP类似物CPT-cAMPS通过恢复EGFR的自磷酸化，逆转西咪替丁对EGF诱导的肝癌细胞增殖和迁移的抑制作用。结论：西咪替丁通过降低细胞内cAMP水平，抑制EGF诱导的肝癌细胞增殖和迁移。西咪替丁可能是一种候选的肝癌化学预防剂。
Background: Cimetidine, a histamine-2 (H-2) receptor antagonist, has been demonstrated to have anticancer effects on colorectal cancer, melanoma and renal cell carcinoma. In the current study, we clarified that cimetidine inhibits both epidermal growth factor (EGF)-induced cell proliferation and migration in hepatocellular carcinoma (HCC) cell lines.Method: HCC cell lines (Hep3B, HLF, SK-Hep-1, JHH-2, PLC/PRF/5 and HLE) were used and cell proliferation was assessed by [H-3]-thymidine incorporation assay. Cell migration was measured by in vitro cell migration assay. Biological effects of cimetidine were assessed with human EGF receptor (EGFR)-expressing mouse fibroblast cells (NR6-WT). The autophosphorylation of EGFR and the activation of other downstream effectors were analyzed by immunoprecipitation and immunoblotting. The concentration of intracellular cyclic AMP (cAMP) was measured by competitive enzyme immunoassay.Results: Cimetidine inhibited both EGF-induced cell proliferation and migration in Hep3B, HLF, SK-Hep-1 and JHH-2, while cimetidine did not affect EGF-induced cell proliferation and migration in PLC/PRF/5 and HLE. Cimetidine was revealed to disrupt the EGF-induced autophosphorylation of EGFR and its downstream effectors, mitogen activated protein kinases and phospholipase C-gamma. To define the molecular basis of this negative regulation, we identified that cimetidine significantly decreased intracellular cAMP levels and that decrement of cAMP inhibited autophosphorylation of EGFR. The cell permeable cAMP analog, CPT-cAMPS reversed the cimetidine-induced inhibition of EGF-induced cell proliferation and cell migration by restoring autophosphorylation of EGFR.Conclusion: Cimetidine inhibited EGF-induced cell proliferation and migration in HCC cell lines by decreasing the concentration of intracellular cAMP levels. Cimetidine may be a candidate chemopreventive agent for HCC.