Konjević G, Jurisić V, Spuzić I
Institute for Oncology and Radiology of Serbia, Belgrade, Yugoslavia.
Breast Cancer Res Treat. 2001 Apr;66(3):255-63. doi: 10.1023/a:1010602822483.
The cytotoxic activity of NK (natural killer) cells is very important in immunological surveillance against the appearance and especially the spread of malignant disease. The aim of this study was to investigate the function of this subpopulation of cells in breast cancer patients in different clinical stages of disease prior to therapy. NK cell activity was determined in breast cancer patients and healthy controls by three different methods: standard 51-chromium-release assay and by the original colorimetric uncorrected and corrected lactate dehydrogenase (LDH) release assay. A discrepancy was shown between the assays, as the uncorrected LDH assay showed, not only, much higher values, but no stage-dependent depression in NK cell activity compared to the chromium-release assay. Further analyses of separately cultured peripheral blood lymphocytes (PBL) revealed that this difference arose from an increasing, clinical stage-dependent, spontaneous LDH release from PBL of breast cancer patients. Furthermore, a stage-dependent increase in intracellular LDH activity of PBL was found, although without difference in LDH-H and LDH-M isotype ratio, compared to controls. Increased spontaneous LDH release and intracellular LDH activity was more evident in young patients, under 40 years. Correction of the original LDH-release assay for the spontaneous LDH release activity from PBL present in the assay, gave values of NK cell activity comparable to those determined by the chromium assay and indicated that breast cancer patients have a significant depression in NK cell activity which correlates with the stage-dependent increase in spontaneous LDH release. Moreover, as both assays measure the secretory, perforin-mediated, NK cell cytotoxic pathway against tumor cells, it can be concluded that the appearance of spontaneous LDH release is an indicator of cell membrane damage which not only allows the loss of LDH, but also of the components of the secretory killing pathway, resulting in NK cell dysfunction with the progression of disease. The novel findings obtained in this work reveal the association of PBL membrane damage with clinical stage of breast cancer that can, aside from reflecting NK cell depression, underlie the defect in other PBL subsets and subsequently facilitate progression of the malignant process.
自然杀伤（NK）细胞的细胞毒性活性在针对恶性疾病的出现尤其是扩散的免疫监视中非常重要。本研究的目的是调查在治疗前处于不同临床疾病阶段的乳腺癌患者中该细胞亚群的功能。通过三种不同方法测定乳腺癌患者和健康对照者的NK细胞活性：标准的51铬释放试验以及原始的比色法未校正和校正乳酸脱氢酶（LDH）释放试验。各试验之间存在差异，因为未校正的LDH试验不仅显示出高得多的值，而且与铬释放试验相比，NK细胞活性没有分期依赖性降低。对单独培养的外周血淋巴细胞（PBL）的进一步分析表明，这种差异源于乳腺癌患者PBL中与临床分期相关的自发性LDH释放增加。此外，发现PBL的细胞内LDH活性有分期依赖性增加，尽管与对照组相比，LDH-H和LDH-M同工酶比例没有差异。40岁以下的年轻患者中，自发性LDH释放增加和细胞内LDH活性更明显。对原始LDH释放试验中存在的PBL自发性LDH释放活性进行校正后，得到的NK细胞活性值与铬试验测定的值相当，表明乳腺癌患者的NK细胞活性有显著降低，这与自发性LDH释放的分期依赖性增加相关。此外，由于两种试验都测量针对肿瘤细胞的分泌性、穿孔素介导的NK细胞细胞毒性途径，因此可以得出结论，自发性LDH释放的出现是细胞膜损伤的一个指标，这不仅导致LDH丢失，还导致分泌性杀伤途径的成分丢失，从而随着疾病进展导致NK细胞功能障碍。这项工作中获得的新发现揭示了PBL膜损伤与乳腺癌临床分期的关联，这除了反映NK细胞抑制外，还可能是其他PBL亚群缺陷的基础，并随后促进恶性过程的进展。
