Department of Pathology, First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China.
PLoS One. 2011;6(6):e21119. doi: 10.1371/journal.pone.0021119. Epub 2011 Jun 16.
C-C chemokine receptor 7 (CCR7) contributes to the survival of certain cancer cell lines, but its role in the proliferation of human non-small cell lung cancer (NSCLC) cells remains vague. Proliferation assays performed on A549 and H460 NSCLC cells using Cell Counting Kit-8 indicated that activation of CCR7 by its specific ligand, exogenous chemokine ligand 21 (CCL21), was associated with a significant linear increase in cell proliferation with duration of exposure to CCL21. The CCL21/CCR7 interaction significantly increased the fraction of cells in the G(2)/M phase of the cell cycle as measured by flow cytometry. In contrast, CCL21/CCR7 had no significant influence on the G(0)/G(1) and S phases. Western blot and real-time PCR indicated that CCL21/CCR7 significantly upregulated expression of cyclin A, cyclin B1, and cyclin-dependent kinase 1 (CDK1), which are related to the G(2)/M phase transition. The expression of cyclin D1 and cyclin E, which are related to the G(0)/G(1) and G(1)/S transitions, was not altered. The CCL21/CCR7 interaction significantly enhanced phosphorylation of extracellular signal-regulated kinase (P-ERK) but not Akt, as measured by Western blot. LY294002, a selective inhibitor of PI3K that prevents activation of the downstream Akt, did not weaken the effect of CCL21/CCR7 on P-ERK. Coimmunoprecipitation further confirmed that there was an interaction between P-ERK and cyclin A, cyclin B1, or CDK1, particularly in the presence of CCL21. CCR7 small interfering RNA or PD98059, a selective inhibitor of MEK that disrupts the activation of downstream ERK, significantly abolished the effects of exogenous CCL21. These results suggest that CCL21/CCR7 contributes to the time-dependent proliferation of human NSCLC cells by upregulating cyclin A, cyclin B1, and CDK1 potentially via the ERK pathway.
C-C 趋化因子受体 7（CCR7）有助于某些癌细胞系的存活，但它在人类非小细胞肺癌（NSCLC）细胞增殖中的作用仍不清楚。使用 Cell Counting Kit-8 对 A549 和 H460 NSCLC 细胞进行的增殖测定表明，CCR7 被其特异性配体外源性趋化因子配体 21（CCL21）激活与细胞增殖呈显著线性增加相关，随着暴露于 CCL21 的时间延长。CCL21/CCR7 相互作用通过流式细胞术显著增加了细胞周期 G(2)/M 期的细胞分数。相比之下，CCL21/CCR7 对 G(0)/G(1) 和 S 期没有显著影响。Western blot 和实时 PCR 表明，CCL21/CCR7 显著上调了细胞周期蛋白 A、细胞周期蛋白 B1 和细胞周期蛋白依赖性激酶 1（CDK1）的表达，这些蛋白与 G(2)/M 期转变有关。与 G(0)/G(1) 和 G(1)/S 转变有关的细胞周期蛋白 D1 和细胞周期蛋白 E 的表达没有改变。CCL21/CCR7 相互作用通过 Western blot 显著增强了细胞外信号调节激酶（P-ERK）的磷酸化，但不影响 Akt。LY294002 是一种选择性的 PI3K 抑制剂，可阻止下游 Akt 的激活，但不能减弱 CCL21/CCR7 对 P-ERK 的作用。免疫沉淀进一步证实，P-ERK 与细胞周期蛋白 A、细胞周期蛋白 B1 或 CDK1 之间存在相互作用，特别是在存在 CCL21 的情况下。CCR7 小干扰 RNA 或 PD98059，一种选择性的 MEK 抑制剂，破坏下游 ERK 的激活，显著消除了外源性 CCL21 的作用。这些结果表明，CCL21/CCR7 通过上调细胞周期蛋白 A、细胞周期蛋白 B1 和 CDK1 来促进人类 NSCLC 细胞的时间依赖性增殖，这可能是通过 ERK 途径实现的。
