POSSIBLE PARTICIPATION OF CHLORIDE ION CHANNELS IN ATP RELEASE FROM CANCER CELLS IN SUSPENSION
POSSIBLE PARTICIPATION OF CHLORIDE ION CHANNELS IN ATP RELEASE FROM CANCER CELLS IN SUSPENSION
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DOI：
10.1111/j.1440-1681.2008.05060.x
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发表时间：
2009-03
影响因子：
2.9
通讯作者：
N. Nejime;S. Kagota;Y. Tada;Kazuki Nakamura;M. Hashimoto;M. Kunitomo;K. Shinozuka
中科院分区：
文献类型：
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作者：
N. Nejime;S. Kagota;Y. Tada;Kazuki Nakamura;M. Hashimoto;M. Kunitomo;K. Shinozuka
1癌细胞必须从原发灶脱离，以启动转移过程。先前，我们证明了在癌细胞存在下内皮细胞中细胞内Ca 2+水平增加，并且来自这些细胞的ATP导致这种增加。本研究通过研究Cl−通道抑制剂和其他药物对人纤维肉瘤细胞（HT-1080细胞）释放ATP的影响，阐明了癌细胞释放ATP的机制。2采用高效液相色谱法（HPLC）和荧光检测法测定细胞外ATP及其代谢产物的水平。3悬浮培养的HT-1080细胞比贴壁培养的HT-1080细胞释放更多的ATP。Cl−通道抑制剂5-硝基-2-（3-苯丙氨基）苯甲酸（100 µmol/L）、钆（100 µ mol/L）和尼氟灭酸（100 µmol/L）均显著抑制HT-1080细胞（1 × 103 /mL）的ATP释放，分别为对照的39.7 ± 6.5%、28.5 ± 2.5%和82.5 ± 4.1%。4两种p-糖蛋白抑制剂（即50 µmol/L奎尼丁和90 µmol/L维拉帕米）对HT-1080细胞的ATP释放均无任何影响。差距连接半通道抑制剂Gap 26（300 µmol/L）轻微但显著降低ATP释放约20%。差距连接抑制剂18-α-大黄酸（10 µmol/L）有抑制HT-1080细胞ATP释放的趋势，但差异无统计学意义。这些发现表明，Cl−通道在从分离的癌细胞释放ATP中起着最重要的作用，间隙连接半通道也与ATP释放有关。
1 Cancer cells must detach from the primary focus to initiate the process of metastasis. Previously, we demonstrated that intracellular Ca2+ levels are increased in endothelial cells in the presence of cancer cells and that ATP derived from these cells causes this increase. The present study clarifies the mechanism of ATP release from cancer cells by investigating the effects of Cl− channel inhibitors and other drugs on ATP release from human fibrosarcoma cells (HT‐1080 cells). 2 Levels of extracellular ATP and its metabolites were measured using high‐performance liquid chromatography (HPLC) with fluorescent detection. 3 Significantly more extracellular ATP was released by suspended than by adherent HT‐1080 cells. The Cl− channel inhibitors 5‐nitro‐2‐(3‐phenylpropylamino) benzoic acid (100 µmol/L), gadolinium (100 µmol/L) and niflumic acid (100 µmol/L) all significantly inhibited ATP release from HT‐1080 cells (1 × 103 /mL) to 39.7 ± 6.5, 28.5 ± 2.5 and 82.5 ± 4.1% of control, respectively. 4 Neither of the p‐glycoprotein inhibitors (i.e. 50 µmol/L quinidine and 90 µmol/L verapamil) had any effect on ATP release from HT‐1080 cells. The gap junction hemichannel inhibitor Gap26 (300 µmol/L) slightly, but significantly, decreased ATP release by approximately 20%. The gap junction inhibitor 18‐α‐glycyrrhetinic acid (10 µmol/L) tended to inhibit ATP release from HT‐1080 cells, but the difference did not reach statistical significance. 5 These findings indicate that Cl− channels play the most important role in ATP release from detached cancer cells and that gap junction hemichannels are also associated with ATP release.