Cell cycle-dependent expression of volume-activated chloride currents in nasopharyngeal carcinoma cells
Cell cycle-dependent expression of volume-activated chloride currents in nasopharyngeal carcinoma cells
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DOI：
10.1152/ajpcell.00182.2002
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发表时间：
2002-10-01
影响因子：
5.5
通讯作者：
Jacob, TJC
中科院分区：
文献类型：
--
作者：
Chen, LX;Wang, LW;Jacob, TJC
应用patchclamp和细胞图像分析技术研究了体积激活Cl-电流、I-Cl（vol）和调节体积减少（RVD）容量在鼻咽癌细胞周期中的表达。低渗刺激导致CNE-2Z细胞膨胀并激活具有线性电导、可忽略不计的时间依赖性失活和接近Cl-平衡电位的逆转电位的Cl-电流。阴离子通透性顺序为I- > Br- > Cl- >葡萄糖酸盐。Cl-通道阻滞剂他莫昔芬、5-硝基-2-（3-苯基丙基氨基）苯甲酸（NPPB）和ATP抑制I-Cl（vol）。通过有丝分裂脱落技术和双化学阻滞（胸苷和羟基脲）技术获得细胞的同步培养。I-Cl（vol）的表达与细胞周期有关，在G(1)期高表达，在S期下调，在M期再次升高。低渗溶液激活RVD， RVD是细胞周期依赖性的，可被Cl-通道阻滞剂NPPB、他莫昔芬和ATP抑制。细胞周期中I-Cl（vol）的表达与RVD容量密切相关，存在一定的功能关系。NPPB （100 muM）对I-Cl（vol）的抑制作用为G(0)/G(1)。这些数据还表明，在细胞周期中，I-Cl（vol）的表达和RVD容量受到主动调节。因此，与RVD相关的体积激活Cl-电流可能在细胞周期进程中发挥重要作用。
Patchclamping and cell image analysis techniques were used to study the expression of the volume-activated Cl- current, I-Cl(vol), and regulatory volume decrease (RVD) capacity in the cell cycle in nasopharyngeal carcinoma cells (CNE-2Z). Hypotonic challenge caused CNE-2Z cells to swell and activated a Cl- current with a linear conductance, negligible time-dependent inactivation, and a reversal potential close to the Cl- equilibrium potential. The sequence of anion permeability was I- > Br- > Cl- > gluconate. The Cl- channel blockers tamoxifen, 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB), and ATP inhibited I-Cl(vol). Synchronous cultures of cells were obtained by the mitotic shake-off technique and by a double chemical-block (thymidine and hydroxyurea) technique. The expression of I-Cl(vol) was cell cycle dependent, being high in G(1) phase, downregulated in S phase, but increasing again in M phase. Hypotonic solution activated RVD, which was cell cycle dependent and inhibited by the Cl- channel blockers NPPB, tamoxifen, and ATP. The expression of I-Cl(vol) was closely correlated with the RVD capacity in the cell cycle, suggesting a functional relationship. Inhibition of I-Cl(vol) by NPPB (100 muM) arrested cells in G(0)/G(1). The data also suggest that expression of I-Cl(vol) and RVD capacity are actively modulated during the cell cycle. The volume-activated Cl- current associated with RVD may therefore play an important role during the cell cycle progress.