v-abl does not abolish IL-6 requirement by murine plasmacytoma cells.
Activation of c-myc by juxtaposition to an immunoglobulin locus and introduction of the v-abl oncogene act synergistically in generating a mouse plasmacytoma (PC). The question arose whether the effect of v-abl could be attributed to a deregulation of interleukin-6 (IL-6) production or responsiveness, in view of the fact that IL-6 exerts potent growth-stimulatory activity on PC cells. We studied the effect of IL-6 on the in vitro growth of primary PCs induced by pristane alone (TEPCs) or by pristane + A-MuLV (ABPCs). Five of 13 TEPCs and 3 of 7 ABPCs responded to IL-6. Macrophage supernatants prepared from both TEPCs and ABPCs had similar stimulatory effects on PC cells. From 30 primary PCs (including both TEPCs and ABPCs), we established 9 in vitro lines, 2 of which expressed v-abl. All were able to grow on macrophage feeder layers. Three types of behavior could be distinguished on the basis of growth in feeder-free cultures in the presence and absence of IL-6. Group I contained 4 IL-6-dependent lines. Group II contained 2 IL-6-independent lines (one v-abl expressor) that grew faster in the presence of IL-6. Group III consisted of 3 feeder-dependent lines (one v-abl expressor) that were not significantly stimulated by IL-6. These findings indicate that v-abl expression does not influence IL-6 dependence or responsiveness by itself. The supernatant of one line in group II was able to stimulate PC cells. All 6 lines of Groups I and II carried a typical (12;15) translocation, while all 3 lines in group III had a variant (6;15) or (15;16) translocation.
Sugiyama
H
H
Department of Tumor Biology, Karolinska Institutet, Stockholm, Sweden.
Wiener
F
F
Babonits
M
M
Silva
S
S
Hirano
T
T
Kishimoto
T
T
Klein
G
G
D000011:Abelson murine leukemia virus; D000818:Animals; D002455:Cell Division / Q000187:drug effects; D016313:Genes, abl / Q000502:physiology*; D006133:Growth Substances / Q000378:metabolism; D015850:Interleukin-6 / Q000494:pharmacology / Q000502:physiology*; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D010954:Plasmacytoma / Q000209:etiology* / Q000235:genetics / Q000276:immunology / Q000473:pathology; D011994:Recombinant Proteins / Q000494:pharmacology; D013729:Terpenes; D014178:Translocation, Genetic; D014407:Tumor Cells, Cultured
D006133:Growth Substances; D015850:Interleukin-6; D011994:Recombinant Proteins; D013729:Terpenes; C009042:pristane