Yanovich S, Hall R E, Weinert C
Cancer Res. 1986 Sep;46(9):4511-5.
K562-R, a pleiotropic drug-resistant cell line established in vitro, and K562-S, the chemotherapy-sensitive parent line, were used as targets in the natural killer cell (NK) system. At each of the effector:target ratios studied, the K562-R demonstrated a decrease in their susceptibility to both unstimulated and interferon-activated NK cells, as compared to the K562-S line. This difference did not appear to be related to a variable expression of NK target structures, as the number of effector:target conjugates was similar, and both lines competed equally well in cold target inhibition experiments. The K562-R cells were not resistant to complement or monocyte-mediated killing, suggesting a relatively specific resistance to cell-mediated killing. These results are compatible with an NK postbinding defect in the K562-R cells and suggest that greater tumorigenicity for pleiotropic drug-resistant cells may in part be due to altered susceptibility to host defense.
K562-R是一种体外建立的多药耐药细胞系，K562-S是化疗敏感的亲代细胞系，它们被用作自然杀伤细胞（NK）系统的靶细胞。在所研究的每个效应细胞与靶细胞比例下，与K562-S细胞系相比，K562-R细胞对未刺激的和干扰素激活的NK细胞的敏感性均降低。这种差异似乎与NK靶结构的可变表达无关，因为效应细胞与靶细胞结合物的数量相似，并且在冷靶抑制实验中两条细胞系的竞争能力相当。K562-R细胞对补体或单核细胞介导的杀伤不具有抗性，表明其对细胞介导的杀伤具有相对特异性的抗性。这些结果与K562-R细胞中NK结合后缺陷相符，并表明多药耐药细胞更高的致瘤性可能部分归因于对宿主防御敏感性的改变。
