Fewtrell C, Lagunoff D, Metzger H
Biochim Biophys Acta. 1981 Jun 22;644(2):363-8. doi: 10.1016/0005-2736(81)90394-1.
Previous experiments on the functional properties of rat basophilic leukaemia cells showed a major anomaly when compared to normal mast cells: though IgE-mediated secretion was dependent on external Ca2+ with both types of cells, substantial non-cytotoxic release with ionophore A23187 could be demonstrated with the normal cells but not with the tumour cells. We now show that when the pH of the incubation medium is increased to 8 it is possible to obtain excellent Ca-dependent, non-cytotoxic secretion from tumour basophils with the ionophores A23187 and ionomycin. These results provide further evidence that secretion from the tumour cells occurs via a mechanism similar to that used by normal mast cells and basophils. Experiments with metabolically inhibited tumour cells suggest that their unusual sensitivity to the cytotoxic effects of Ca2+ ionophores may be related to their ability to sequester intracellular calcium. Changes in the conditions of cell culture appeared to produce substantial and at least partially reversible changes in responsiveness to IgE-mediated triggering and ionophores.
先前对大鼠嗜碱性白血病细胞功能特性的实验表明，与正常肥大细胞相比存在一个主要异常：尽管两种细胞的IgE介导分泌均依赖于细胞外Ca2+，但正常细胞可通过离子载体A23187表现出大量非细胞毒性释放，而肿瘤细胞则不然。我们现在表明，当将孵育培养基的pH值提高到8时，使用离子载体A23187和离子霉素可从肿瘤嗜碱性粒细胞获得良好的钙依赖性非细胞毒性分泌。这些结果进一步证明，肿瘤细胞的分泌是通过与正常肥大细胞和嗜碱性粒细胞类似的机制发生的。对代谢受抑制的肿瘤细胞进行的实验表明，它们对Ca2+离子载体细胞毒性作用的异常敏感性可能与其螯合细胞内钙的能力有关。细胞培养条件的变化似乎会对IgE介导的触发和离子载体的反应性产生实质性且至少部分可逆的变化。
