Hu Lichao, Xia Longfei, Zhou Hong, Wu Biao, Mu Yuan, Wu Ying, Yan Jinchuan
Department of Cardiology, Affiliated Hospital of Jiangsu University, 438 Jiefang Road, Zhenjiang, Jiangsu, 212013, People's Republic of China.
Tumour Biol. 2013 Oct;34(5):2573-81. doi: 10.1007/s13277-013-0803-2. Epub 2013 Apr 25.
Our previous study has demonstrated that tissue factor-factor VIIa (TF/FVIIa) complex promotes the proliferation and migration of colon cancer cell line SW620 through the activation of protease-activated receptor 2 (PAR2). In the current study, the underlying molecular mechanisms of TF/FVIIa/PAR2 signaling in SW620 cells were further explored, with the focus on the role of activator protein-1 (AP-1) subunit c-Jun. The results revealed that PAR2-AP and FVIIa could upregulate c-Jun expression and c-Jun phosphorylation in SW620 cells in a time-dependent manner. The effect of FVIIa was significantly blocked by anti-TF and anti-PAR2 antibodies. Protein kinase Cα (PKCα) inhibitor safingol and extracellular signal-regulated kinase 1 and 2 (ERK1/2) inhibitor U0126 abrogated the activation of c-Jun. In contrast, Ca(2+) chelators EGTA and thapsigargin, and p38MAPK inhibitor SB203580 had no effect. Suppression of c-Jun/AP-1 activation using a natural inhibitor curcumin decreased the expression of caspase-3, MMP-9, and TF, as well as the proliferation and migration of SW620 cells induced by PAR2-AP or FVIIa. Collectively, our findings suggest that c-Jun/AP-1 activation is required for TF/FVIIa/PAR2-induced SW620 cell proliferation and migration. PKCα and ERK1/2 are located upstream of c-Jun/AP-1 in this signaling pathway. Pharmacological inhibition of this pathway might be a novel strategy for colon cancer therapy.
我们之前的研究表明，组织因子-因子VIIa（TF/FVIIa）复合物通过激活蛋白酶激活受体2（PAR2）促进结肠癌细胞系SW620的增殖和迁移。在本研究中，我们进一步探索了SW620细胞中TF/FVIIa/PAR2信号传导的潜在分子机制，重点关注激活蛋白-1（AP-1）亚基c-Jun的作用。结果显示，PAR2-AP和FVIIa可使SW620细胞中的c-Jun表达和c-Jun磷酸化呈时间依赖性上调。抗TF和抗PAR2抗体可显著阻断FVIIa的作用。蛋白激酶Cα（PKCα）抑制剂沙芬戈和细胞外信号调节激酶1和2（ERK1/2）抑制剂U0126可消除c-Jun的激活。相反，Ca(2+)螯合剂EGTA和毒胡萝卜素以及p38丝裂原活化蛋白激酶（p38MAPK）抑制剂SB203580则无此作用。使用天然抑制剂姜黄素抑制c-Jun/AP-1激活可降低caspase-3、基质金属蛋白酶-9（MMP-9）和TF的表达，以及PAR2-AP或FVIIa诱导的SW620细胞的增殖和迁移。总的来说，我们的研究结果表明，c-Jun/AP-1激活是TF/FVIIa/PAR2诱导SW620细胞增殖和迁移所必需的。在该信号通路中，PKCα和ERK1/2位于c-Jun/AP-1的上游。对该通路进行药理抑制可能是结肠癌治疗的一种新策略。
