Lemoli R M, Fortuna A
Institute of Hematology, University of Bologna, Italy.
Leuk Lymphoma. 1996 Feb;20(5-6):457-64. doi: 10.3109/10428199609052429.
Here we review our recent experience addressing the role of SCF in multiple myeloma (MM). We first investigated the proliferation of MM cell lines and bone marrow samples from myeloma patients in response to rh-SCF alone and combined with Interleukin-6 (IL-6), IL-3, and IL-3/GM-CSF fusion protein PIXY 321. Neoplastic plasma cells were highly purified (>90%) by immunomagnetic depletion of T, myeloid, monocytoid and NK cells. The number of S-phase cells was evaluated after 3 days of liquid culture by the bromodeoxyuridine (BRDU) incorporation assay. The proliferation of RPMI 8226 and U266 cell lines was also assessed by a clonogenic assay. All the experiments were performed in serum-free conditions. RPMI 8226 cell line was not stimulated by SCF which also did not augment the proliferative activity of IL-6, IL-3 and PIXY-321. Conversely, SCF addition resulted in 2.4-fold increase of the number of U266 colonies and in a higher number of U266 and MT3 cells in S-phase. The c-kit ligand also enhanced the proliferation of MT3 and U266 cells mediated by the other cytokines. Anti-SCF polyclonal antibodies completely abrogated the proliferative response of MT3 cells to exogenous SCF and markedly reduced the spontaneous growth of the same cell line. Reverse transcriptase-polymerase chain reaction amplification (RT-PCR) did detect SCF mRNA in MT3 and RPMI 8226 cells. Moreover, secreted SCF was found, in a biologically active form, in the supernatant of the two cell lines by the MO7e proliferation assay. These results suggest that an autocrine proliferative loop may be operative in MT3 cell line. When tested on fresh myeloma samples, SCF increased the number of S-phase plasma cells (4.7 +/- 1.6% vs 3.4 +/- 1.3% in control cultures; p = 0.02). Significant proliferation was also induced by IL6, IL-3 and PIXY-321. The addition of SCF significantly enhanced the proliferation of myeloma cells responsive to IL-6. Preliminary experiments performed on circulating plasma cells and myeloma precursors further supported the role of SCF on the proliferation of the neoplastic clone in MM.
在此，我们回顾了我们最近关于干细胞因子（SCF）在多发性骨髓瘤（MM）中作用的研究经验。我们首先研究了骨髓瘤患者的骨髓瘤细胞系和骨髓样本对单独的重组人干细胞因子（rh-SCF）以及与白细胞介素-6（IL-6）、白细胞介素-3（IL-3）和IL-3/粒细胞-巨噬细胞集落刺激因子（GM-CSF）融合蛋白PIXY 321联合使用时的增殖反应。通过对T细胞、髓样细胞、单核细胞样细胞和自然杀伤细胞（NK细胞）进行免疫磁珠清除，高度纯化（>90%）肿瘤性浆细胞。通过溴脱氧尿苷（BRDU）掺入试验在液体培养3天后评估S期细胞数量。还通过克隆形成试验评估了RPMI 8226和U266细胞系的增殖情况。所有实验均在无血清条件下进行。RPMI 8226细胞系不受SCF刺激，SCF也未增强IL-6、IL-3和PIXY-321的增殖活性。相反，添加SCF导致U266集落数量增加2.4倍，且S期的U266和MT3细胞数量更多。干细胞因子配体还增强了其他细胞因子介导的MT3和U266细胞的增殖。抗SCF多克隆抗体完全消除了MT3细胞对外源性SCF的增殖反应，并显著降低了同一细胞系的自发生长。逆转录聚合酶链反应扩增（RT-PCR）确实在MT3和RPMI 8226细胞中检测到了SCF信使核糖核酸（mRNA）。此外，通过MO7e增殖试验在两种细胞系的上清液中发现了具有生物活性形式的分泌型SCF。这些结果表明，自分泌增殖环可能在MT3细胞系中起作用。当在新鲜骨髓瘤样本上进行测试时，SCF增加了S期浆细胞的数量（4.7±1.6%，而对照培养物中为3.4±1.3%；p = 0.02）。IL-6、IL-3和PIXY-321也诱导了显著的增殖。添加SCF显著增强了对IL-6有反应的骨髓瘤细胞的增殖。对循环浆细胞和骨髓瘤前体细胞进行的初步实验进一步支持了SCF在MM中对肿瘤克隆增殖的作用。
