Establishment of myeloma cell lines and biotechnological study on the regulatory mechanisms of myeloma cell growth.

由于骨髓基质细胞在骨髓瘤细胞的生长中起重要作用，我们使用巨噬细胞（基质细胞的一员）作为饲养层用于建立骨髓瘤细胞系。已经建立了超过6种骨髓瘤细胞系。结果表明：1）巨噬细胞对骨髓瘤细胞的生长有促进作用，可用于骨髓瘤细胞系的建立。2)骨髓瘤细胞响应于IL-6和IL-1而增殖。由巨噬细胞分泌的IL-6主要介导刺激作用。13）使用巨噬细胞作为饲养层，已经建立了6个骨髓瘤细胞系，并且4个骨髓瘤细胞系已经在体外维持3-9个月。4)两种骨髓源性细胞系的增殖完全依赖于巨噬细胞或IL-6。然而，4个髓外病变衍生的细胞系自发增殖。5)两种骨髓瘤细胞系ILKM 3和KM 4在N-RAS外显子2.6的密码子61处存在点突变。虽然巨噬细胞在以小细胞数使用时对骨髓瘤细胞生长具有积极作用，但当以较高细胞数使用时，它们也具有负面作用。这种负作用是通过巨噬细胞和骨髓瘤细胞之间的白细胞粘附分子的相互作用介导的。

Since bone marrow Stromal cells play an important role in the growth of myeloma cells, we used macrophages, a member of stromal cells, as a feeder layer for establishing myeloma cel lines. More than 6 myeloma cell lines have been established. Then, these cell lines were used for the analysis of myeloma cell growth, giving following results.1)Macrophages have positive effect on the growth of myeloma cells and they are useful for establishing myeloma cell lines. 2)Myeloma cells proliferate in response to IL-6 and IL-1. IL-6 secreted by macrophages primarily mediates the stimulatory effect. i 3)With using macrophages as a feeder layer, 6 myeloma cell lines have been established and 4 myeloma cell lines have been maintained in vitro for 3-9 months. 4)Two bone marrow-derived cell lines proliferate absolutely dependently on macrophages or IL-6. However, 4 extramedullary lesion-derived cell lines proliferate spontaneously. 5)Two myeloma cell lines, ILKM3 and KM4, have a point mutation in codon 61 of N-RAS exon 2.6)Although macrophages have positive effect on myeloma cell growth when used at a small cell number, they also have negative effect when used at a higher cell number. Such negative effect is mediated through interaction of leukocyte adhesion molecules between macrophages and myeloma cells.