Regulation of the interleukin-3 (IL-3) receptor by IL-3 in the fetal liver-derived FL5.12 cell line.
To determine the effects of a cytokine on cognate receptor expression in normal and neoplastic cells, the interleukin-3 receptor (IL-3R) complex was examined in the parental IL-3-dependent line FL5.12, which was isolated from fetal liver, and in autocrine- and v-abl-transformed derivative lines. IL-3 decreased the amount of the IL-3R alpha and beta chains detected on the cell surface of the parental IL-3-dependent cells. In contrast, high levels of IL-3R beta were constitutively detected on the autocrine-transformed lines in the absence and presence of exogenous IL-3. Only low levels of IL-3R beta were observed in the two v-abl-transformed derivative cell lines examined, which no longer required IL-3 for growth. The levels of the IL-3R alpha chain detected were similar in these transformed cells and were not regulated by IL-3. These results were substantiated further by RNA analysis, because IL-3 decreased the levels of IL-3R transcripts in the parental factor-dependent FL5.12 line. The pattern of IL-3R gene expression was opposite to that of other receptors or proto-oncogenes, because RNA transcripts for all other genes examined were induced by IL-3. We conclude that IL-3 tightly controls IL-3R expression in the IL-3-dependent FL5.12 cells, whereas steady-state mRNA levels were not altered in the two v-abl-transformed derivative cell lines examined in this study.
Algate
P A
PA
Department of Microbiology and Immunology, East Carolina University School of Medicine, Greenville, NC 27858.
Steelman
L S
LS
Mayo
M W
MW
Miyajima
A
A
McCubrey
J A
JA
D000818:Animals; D002455:Cell Division; D002460:Cell Line; D002461:Cell Line, Transformed; D005786:Gene Expression Regulation; D016313:Genes, abl; D006207:Half-Life; D006412:Hematopoietic Stem Cells / Q000166:cytology; D007377:Interleukin-3 / Q000494:pharmacology*; D008099:Liver / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D012333:RNA, Messenger / Q000378:metabolism; D016185:Receptors, Interleukin-3 / Q000235:genetics*; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D007377:Interleukin-3; D012333:RNA, Messenger; D016185:Receptors, Interleukin-3