Iwagaki H, Marutaka M, Nezu M, Suguri T, Tanaka N, Orita K
First Department of Surgery, Okayama University Medical School, Japan.
Res Commun Mol Pathol Pharmacol. 1994 Aug;85(2):141-9.
Cell membrane fluidity (CMF) and transferrin receptor (Tf-R) expression were investigated in K562 cells, a human chronic myelocytic leukemia cell line, treated by gamma-interferon (IFN-gamma). CMF was increased using spin-labeled electron spin resonance techniques, and Tf-R expression was measured by flow cytometric analysis with an EPICS-750 flow cytometer/cell sorter. Treatment of K562 cells in suspension culture with IFN-gamma for as long a time as 6 hr caused an increase in CMF, and then returned to the level of control cells at 12 hr. Conversely, by 24 hr after the beginning of treatment, the rigidity of CMF was increased. Thus, the changes of IFN-gamma-induced CMF was biphasic. While the early change of CMF is related to signal generation and transmission, the later change may reflect changes in lipid compositions and/or cytoskeletal complexes of the plasma cell membrane. A significant increase of Tf-R after 6 hr and 24 hr in number was obtained by treatment of K562 cells with IFN-gamma, but at 12 hr the number of Tf-R did not differ from the control. These results suggested that the early phase of upregulation of Tf-R induced by IFN-gamma was caused by increased CMF, and the late phase of upregulation of Tf-R was due to increased rigidity of CMF. In conclusion, the state of CMF associated with a certain receptor expression in cells is not rigid and can be modulated to some extent by exogenous influences. This may open possibilities of some adjuvant therapeutic measures in malignant diseases by increasing the antigenicity of tumor cells.
在经γ干扰素（IFN-γ）处理的人慢性粒细胞白血病细胞系K562细胞中，研究了细胞膜流动性（CMF）和转铁蛋白受体（Tf-R）的表达。使用自旋标记电子自旋共振技术检测CMF，并用EPICS-750流式细胞仪/细胞分选仪通过流式细胞术分析测定Tf-R的表达。将悬浮培养的K562细胞用IFN-γ处理长达6小时会导致CMF增加，然后在12小时时恢复到对照细胞水平。相反，在处理开始后24小时，CMF的刚性增加。因此，IFN-γ诱导的CMF变化是双相的。虽然CMF的早期变化与信号产生和传递有关，但后期变化可能反映了质膜脂质组成和/或细胞骨架复合物的变化。用IFN-γ处理K562细胞6小时和24小时后，Tf-R数量显著增加，但在12小时时Tf-R数量与对照无差异。这些结果表明，IFN-γ诱导的Tf-R上调的早期阶段是由CMF增加引起的，而Tf-R上调的后期阶段是由于CMF刚性增加。总之，与细胞中特定受体表达相关的CMF状态不是固定不变的，并且可以在一定程度上受到外源影响的调节。这可能通过增加肿瘤细胞的抗原性为恶性疾病的一些辅助治疗措施开辟可能性。
