Borinaga A M, Millar B C, Bell J B, Joffe J K, Millar J L, Gooding R, Riches P, McElwain T J
Section of Medicine, Institute of Cancer Research, Sutton, Surrey.
Br J Haematol. 1990 Dec;76(4):476-83. doi: 10.1111/j.1365-2141.1990.tb07903.x.
Several groups have claimed that IL-6 is a growth factor for human myeloma cells in vitro. Bone marrow aspirates from 30 patients at different stages of treatment with VAMP/high dose melphalan, were examined for myeloma colony formation (MY-CFUc) using a clonogenic assay in vitro. Myeloma cells from 16/30 patients produced MY-CFUc in our assay system, which uses heavily irradiated HL60 cells as an underlay in soft agar. These heavily irradiated cells were shown to be essential for the inhibition of granulocyte-macrophage colonies (GM-CFUc). The addition of recombinant human IL-6 (10 ng/plate) reduced the number of bone marrow samples which produced MY-CFUc from 16 to six. Furthermore, the addition of antibody to IL-6 (1 microgram/plate) failed to inhibit MY-CFUc from 6/7 samples. Conditioned medium from human peripheral blood mononuclear cells (PBMC-CM) contains approximately 2 ng/ml IL-6 and can be used to stimulate the growth and maintenance of the B9 murine IL-6 dependent hybridoma cell line. Recombinant human IL-6 supported the growth of B9 cells in a clonogenic assay and growth was inhibited by anti-IL-6 in the presence of rhIL-6 or PBMC-CM. Mononuclear cells from a second group of myeloma patients were cultured in soft agar in a mixture of PBMC-CM and fresh growth medium. Nine of the 10 samples produced myeloid colonies which consisted of granulocytes, monocytes and macrophages and the number of colonies was reduced by at least 50% in 6/8 samples when anti-IL-6 was added to the cultures. In no instance were MY-CFUc produced. Also, conditioned medium from the bladder carcinoma cell line 5637, which is used routinely as a source of granulocyte-macrophage colony stimulating factor (GM-CSF), contains approximately 4 ng/ml IL-6. Although rhIL-6 failed to stimulate GM-CFUc in the absence of other growth factors, addition of anti-IL-6 to cultures containing a suboptimal amount of 5637-CM reduced the number of colonies by 50%. These data provide evidence that IL-6 is a cofactor for the growth of myeloid precursors but does not affect the proliferation of human myeloma cells in vitro.
有几个研究小组称，白细胞介素-6（IL-6）在体外是人类骨髓瘤细胞的生长因子。对30例接受VAMP/大剂量美法仑不同治疗阶段患者的骨髓穿刺液，采用体外克隆形成试验检测骨髓瘤集落形成（MY-CFUc）。在我们的试验系统中，30例患者中有16例的骨髓瘤细胞产生了MY-CFUc，该系统使用经大量照射的HL60细胞作为软琼脂中的底层细胞。已证明这些经大量照射的细胞对于抑制粒细胞-巨噬细胞集落（GM-CFUc）至关重要。添加重组人IL-6（10 ng/平板）可使产生MY-CFUc的骨髓样本数量从16个减少至6个。此外，添加抗IL-6抗体（1微克/平板）未能抑制7个样本中6个样本的MY-CFUc。人外周血单个核细胞条件培养基（PBMC-CM）含有约2 ng/ml的IL-6，可用于刺激B9小鼠IL-6依赖性杂交瘤细胞系的生长和维持。在克隆形成试验中，重组人IL-6支持B9细胞的生长，在存在重组人IL-6或PBMC-CM的情况下，抗IL-6可抑制其生长。将第二组骨髓瘤患者的单个核细胞在PBMC-CM和新鲜生长培养基的混合物中于软琼脂中培养。10个样本中有9个产生了由粒细胞、单核细胞和巨噬细胞组成的髓系集落，当向培养物中添加抗IL-6时，8个样本中有6个样本的集落数量减少了至少50%。未出现产生MY-CFUc的情况。此外， routinely used as a source of granulocyte-macrophage colony stimulating factor (GM-CSF)的膀胱癌细胞系5637的条件培养基含有约4 ng/ml的IL-6。尽管在没有其他生长因子的情况下重组人IL-6未能刺激GM-CFUc，但向含有次优量5637-CM的培养物中添加抗IL-6可使集落数量减少50%。这些数据提供了证据表明IL-6是髓系前体细胞生长的辅助因子，但在体外不影响人类骨髓瘤细胞的增殖。
