Differential interleukin-6 (IL-6) responses of three established myeloma cell lines in the presence of soluble human IL-6 receptors.
We investigated the possible influence of recombinant (r) sIL-6R on the growth of three IL-6 non-responsive or weakly IL-6 responsive long-term myeloma cell lines. The three cell lines chosen for the study (U266, L363 and Fravel) all expressed gp130 but differed in their expression of IL-6R and IL-6. mRNA analysis by northern blot and reverse transcriptase polymerase reaction showed that the cell line U266 was the only one that expressed IL-6 mRNA. Only U266 and L363 expressed IL-6R mRNA. 125I-rIL-6 binding studies and FACS analysis, using biotinylated IL-6 and antibodies directed against the IL-6R and gp130, showed corresponding results on the protein level. Addition of rsIL-6R resulted in induction of IL-6 responsiveness in L363 cells, whereas the 3H-thymidine incorporation of the cell lines U266 and Fravel was unaffected by rsIL-6R addition. In conclusion, the IL-6 unresponsive growth of several long-term myeloma cell lines in vitro can in some, but not all cases, be due to a deficiency in exogenous sIL-6R.
Diamant
M
M
Medical Department TTA 7544 Rigshospitalet, Copenhagen, Denmark.
Hansen
M B
MB
Rieneck
K
K
Svenson
M
M
Yasukawa
K
K
Bendtzen
K
K
D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism*; D050822:Cytokine Receptor gp130; D005434:Flow Cytometry; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D007457:Iodine Radioisotopes; D008562:Membrane Glycoproteins / Q000235:genetics; D009101:Multiple Myeloma / Q000378:metabolism / Q000473:pathology*; D012333:RNA, Messenger / Q000235:genetics; D011869:Radioligand Assay; D018123:Receptors, Interleukin / Q000235:genetics / Q000378:metabolism*; D019947:Receptors, Interleukin-6; D011994:Recombinant Proteins / Q000378:metabolism / Q000494:pharmacology; D015398:Signal Transduction; D013936:Thymidine / Q000378:metabolism; D014316:Tritium; D014407:Tumor Cells, Cultured
D015703:Antigens, CD; C494199:IL6ST protein, human; D015850:Interleukin-6; D007457:Iodine Radioisotopes; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D018123:Receptors, Interleukin; D019947:Receptors, Interleukin-6; D011994:Recombinant Proteins; D014316:Tritium; D050822:Cytokine Receptor gp130; D013936:Thymidine