Interacting post-muscarinic receptor signaling pathways potentiate matrix metalloproteinase-1 expression and invasion of human colon cancer cells.
Interacting post-muscarinic receptor signaling pathways potentiate matrix metalloproteinase-1 expression and invasion of human colon cancer cells.
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DOI：
10.1042/bcj20160704
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发表时间：
2017-02-20
期刊：
影响因子：
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通讯作者：
Raufman JP
中科院分区：
文献类型：
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作者：
Said AH;Hu S;Abutaleb A;Watkins T;Cheng K;Chahdi A;Kuppusamy P;Saxena N;Xie G;Raufman JP
结肠癌中 M3 毒蕈碱受体 (M3R) 表达增加； M3R 激活通过与表皮生长因子受体 (EGFR) 串扰、EGFR 后激活丝裂原激活蛋白激酶 (MAPK) ERK1/2 以及诱导基质金属蛋白酶-1 (MMP1) 表达来刺激结肠癌细胞侵袭。 MMP1 表达与肿瘤转移和不良后果密切相关。在这里，我们询问其他 MAPK 是否调节 M3R 激动剂诱导的 MMP1 表达。除了激活 ERK1/2 之外，我们还发现用乙酰胆碱 (ACh) 处理结肠癌细胞会刺激 p38 MAPK 发生强烈的时间和剂量依赖性磷酸化。与 ERK1/2 激活不同，ACh 诱导的 p38 磷酸化不依赖于 EGFR，并可通过抑制蛋白激酶 C-α (PKC-α) 来阻断。单独抑制 PKC-α、EGFR、ERK1/2 或 p38-α/β 的激活会减弱但不会消除 ACh 诱导的 MMP1 表达，这一发现预测了这些途径之间的增强相互作用。事实上，通过将细胞与 EGFR 或 MEK/ERK1/2 抑制剂与 p38-α/β 抑制剂联合培养，ACh 诱导的 MMP1 表达被消除。通过佛波醇 12-肉豆蔻酸酯 13-乙酸酯 (PMA) 和 EGF 的组合直接激活 PKC-α 和 EGFR，增强 MMP1 基因和蛋白表达以及细胞侵袭。 PMA 和 ACh 诱导的 MMP1 表达通过抑制 Src 强烈减弱，并通过同时抑制 p38-α/β 和 Src 消除，表明 Src 介导 PKC-α 和 EGFR 信号传导之间的串扰。使用 siRNA 敲低，我们将 p38-α 鉴定为相关的 p38 同工型。总的来说，这些研究揭示了毒蕈碱后受体信号通路之间新的功能相互作用，可增强 MMP1 表达并驱动结肠癌细胞侵袭。针对这些增强的相互作用具有治疗潜力。
M3 muscarinic receptor (M3R) expression is increased in colon cancer; M3R activation stimulates colon cancer cell invasion via cross-talk with epidermal growth factor receptors (EGFR), post-EGFR activation of mitogen-activated protein kinase (MAPK) ERK1/2, and induction of matrix metalloproteinase-1 (MMP1) expression. MMP1 expression is strongly associated with tumor metastasis and adverse outcomes. Here, we asked whether other MAPKs regulate M3R agonist-induced MMP1 expression. In addition to activating ERK1/2, we found that treating colon cancer cells with acetylcholine (ACh) stimulated robust time- and dose-dependent phosphorylation of p38 MAPK. Unlike ERK1/2 activation, ACh-induced p38 phosphorylation was EGFR-independent and blocked by inhibiting protein kinase C-α (PKC-α). Inhibiting activation of PKC-α, EGFR, ERK1/2, or p38-α/β alone attenuated but did not abolish ACh-induced MMP1 expression, a finding that predicted potentiating interactions between these pathways. Indeed, ACh-induced MMP1 expression was abolished by incubating cells with either an EGFR or MEK/ERK1/2 inhibitor combined with a p38-α/β inhibitor. Activating PKC-α and EGFR directly with the combination of phorbol 12-myristate 13-acetate (PMA) and EGF potentiated MMP1 gene and protein expression, and cell invasion. PMA- and ACh-induced MMP1 expression were strongly diminished by inhibiting Src and abolished by concurrently inhibiting both p38-α/β and Src, indicating that Src mediates the cross-talk between PKC-α and EGFR signaling. Using siRNA knockdown, we identified p38-α as the relevant p38 isoform. Collectively, these studies uncover novel functional interactions between post-muscarinic receptor signaling pathways that augment MMP1 expression and drive colon cancer cell invasion; targeting these potentiating interactions has therapeutic potential.