The metastatic potential of cancer cells is related to their migratory ability, which is influenced by in vivo microenvironment possessing specific physiochemical factors including electric properties. In the present study, we isolated two different subsets of lung adenocarcinoma H1975 cells, as side population (SP) and main population (MP). SP cells were demonstrated to have cancer stem cell characteristics. Using a microscale device to provide physiological direct-current electric field (dcEF), we investigated the electrotactic responses of the SP and MP cells. The results showed that both SP and MP cells exhibited enhanced cathodal migration ability with actin reorganization and transient intracellular calcium ions ([Ca²⁺]_i) increase under dcEF stimulation. For SP cells, the treatment of either stretch-activated cation channels (SACCs) inhibitor or the blockage of intracellular Ca²⁺ release could partially inhibited dcEF-activated [Ca²⁺]_i increase, and the concomitant treatment led to a complete inhibition. For MP cells, SACCs activation was entirely responsible for EF-activated increase of [Ca²⁺]_i. All these results suggested that that intracellular Ca²⁺ activation may be associated with cancer cell tumorigenicity and metastasis.

癌细胞的转移潜力与其迁移能力有关，这受具有特定物理化学因素（包括电学性质）的体内微环境的影响。在本研究中，我们分离了肺腺癌H1975细胞的两个不同子集，即侧群（SP）和主要群（MP）。SP细胞被证明具有癌症干细胞特征。使用微型设备提供生理直流电场（dcEF），我们调查了SP和MP细胞的电趋向反应。结果表明，SP和MP细胞均表现出增强的阴极迁移能力，并伴有肌动蛋白重组和瞬时细胞内钙离子（[Ca ²⁺ ] _i）在dcEF刺激下增加。对于SP细胞，对拉伸激活的阳离子通道（SACCs）抑制剂的处理或对细胞内Ca ²⁺释放的阻滞都可以部分抑制dcEF激活的[Ca ²⁺ ] _i的增加，并且伴随的处理导致完全的抑制。对于MP细胞，SACC的活化完全是由EF活化的[Ca ²⁺ ] _i引起的。所有这些结果表明，细胞内Ca ²⁺活化可能与癌细胞的致瘤性和转移有关。