OBJECTIVETo study the anti-myeloma activity of interleukin-2 activated bone marrow (ABM).

METHODSBone marrow mononuclear cells (BMMNC) from multiple myeloma and iron-deficiency anemia patients were cultured in the presence of rIL-2. The anti-myeloma activity of ABM against U266 cells, cells expressing surface CD45, CD38, CD138, the levels of TNF-alpha and IFN-gamma in ABM culture supernatant were measured with MTT method, flow cytometry and ELISA method respectively after bone marrow was activated with rIL-2 for 24 and 72 hours.

RESULTSThe tumor-killing activities against U266 cells of ABM were significantly increased compared with that of non-activated bone marrow (NBM) at 72 hours [(69.70 +/- 26.57)% vs (43.20 +/- 12.39)%, P < 0.05] and 24 hours [(34.25 +/- 11.93)% vs (26.53 +/- 5.48)%]. The CD45(-)CD38(+)CD138(+) cells of ABM from myeloma group at 72 hours were decreased from (8.46 +/- 3.66)% to (4.79 +/- 1.56)% (P < 0.05). TNF-alpha and IFN-gamma were detectable after cultured for 24 hours in both normal control group and myeloma group and went higher at 72 hours. The level of TNF-alpha and IFN-gamma were significantly increased in ABM compared with that in NBM (P < 0.05). Meanwhile, there was a positive relationship between the level of TNF-alpha, IFN-gamma and cytotoxicity of ABM from normal control group at 24 hours and 72 hours (P < 0.05), and was a negative relationship between TNF-alpha and IFN-gamma levels and the CD45(-)CD38(+)CD138(+) cells in myeloma group at 72 hours (P < 0.05).

CONCLUSIONNormal BMMNCs activated with rIL-2 have tumor-killing activities against U266 cells. Myeloma cells and tumor burden were decreased in myeloma bone marrow after the marrow was activated with rIL-2. Production of TNF-alpha and IFN-gamma from bone marrow cells including T cells, monocyte-macrophages and NK cells activated with rIL-2 might be involved in anti-myeloma activity of ABM.