IL-2 modulation of murine T-cell oncogene expression.
C-myb, a cellular oncogene associated with normal thymic development, was found to be highly expressed in four interleukin 2 (IL-2)-independent T-cell lines, but not in two of three IL-2-dependent T-cell lines. The IL-2-dependent lines, HT2 and CTLL-2, were found to have low levels of c-myb mRNA in the presence of IL-2. However, short-term IL-2 depletion resulted in at least fivefold increases in c-myb message. Add-back of IL-2 after 30 hr IL-2 depletion of CTLL-2 cells resulted in return to baseline low-level c-myb mRNA. Expression of the oncogenes myc, bas, raf, and abl as well as the T-cell genes Thy-1 and CT beta did not parallel that of c-myb. These studies indicate that removal of a growth factor can result in increased levels of a specific cellular oncogene and that two nuclear protooncogenes (c-myb and c-myc) are expressed differentially during cell growth. These results may help to explain aspects of intrathymic T-cell differentiation where there is very high c-myb expression in the face of limiting amounts of growth factors such as IL-2.
D000818:Animals; D002453:Cell Cycle; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000187:drug effects*; D007376:Interleukin-2 / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009693:Nucleic Acid Hybridization; D011519:Proto-Oncogenes / Q000187:drug effects*; D012333:RNA, Messenger / Q000235:genetics; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology
D007376:Interleukin-2; D012333:RNA, Messenger