Assessment of the therapeutic potential of cytokines, cytotoxic drugs and effector cell populations for the treatment of multiple myeloma using the 5T33 murine myeloma model

• Published in: Immunology and cell biology Vol. 73; no. 4; p. 326
• Main Authors: Manning, L S, Chamberlain, N L, Leahy, M F, Cordingley, F T
• Format: Journal Article
• Language: English
• Published: United States 01.08.1995
• Subjects: Animals; Antineoplastic Agents - therapeutic use; Cell Division - drug effects; Cell Division - immunology; Cell Transformation, Neoplastic - drug effects; Cell Transformation, Neoplastic - immunology; Combined Modality Therapy; Cytokines - therapeutic use; Cytotoxicity, Immunologic; Female; Humans; Interferon-alpha - therapeutic use; Interleukins - therapeutic use; Killer Cells, Lymphokine-Activated - immunology; Killer Cells, Natural - immunology; Male; Melphalan - therapeutic use; Mice; Mice, Inbred C57BL; Multiple Myeloma - drug therapy; Multiple Myeloma - immunology; Multiple Myeloma - therapy; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha - therapeutic use
• ISSN: 0818-9641
• DOI: 10.1038/icb.1995.50

The therapeutic potential of six cytokines, eight cytotoxic drugs and two effector cell populations for the treatment of multiple myeloma was assessed in vitro using the 5T33 murine myeloma model. The efficacy of combination IFN-alpha and melphalan therapy was also evaluated in vitro and in vivo. Of the cytokines tested in vitro using the MTT assay, only IFN-alpha demonstrated significant inhibition of myeloma cell growth at non-toxic concentrations (ED50 = 1508.3 +/- 181.3 U/mL and 2617.9 +/- 334.0 U/mL for murine IFN-alpha [mIFN-alpha] and human IFN-alpha hybrid B/D [hIFN-alpha B/D], respectively). The ED50 for the eight cytotoxic drugs tested ranged from 2.3 x 10(-9) to 4.3 x 10(-13) mol/L and all were within the therapeutic range for humans. Combination hIFN-alpha B/D and melphalan were found to be additive in their inhibitory effects on myeloma cell growth in vitro and this finding was confirmed in vivo in C57BL/KaLwRij mice bearing disseminated 5T33 myeloma. Control animals demonstrated a median survival duration of 25.3 days whereas hIFN-alpha B/D or melphalan treatment alone increased survival to 30.5 and 33.3 days, respectively (P < 0.001). Combination IFN-alpha/melphalan therapy increased median survival duration to 38.5 days (P < 0.001) which was also significantly greater than that obtained with single agent therapy (P < 0.01). The murine myeloma cells were found to be resistant to NK cell lysis but susceptible to lysis by LAK cells (49.3 +/- 6.3% lysis at an effector to target ratio of 100:1).