EXPRESSION OF THE INTERLEUKIN-6 (IL-6), IL-6 RECEPTOR, AND GP130 GENES IN ACUTE-LEUKEMIA

Expression patterns of interleukin-6 (IL-6), IL-6 receptor (IL-6R), an d gp130 genes in 39 patients with acute myeloid leukemia (AML), in 23 patients with acute lymphoblastic leukemia (ALL), and in 7 patients wi th acute mixed lineage leukemia (AMLL) were studied by quantitative re verse transcriptase-polymerase chain reaction. Significant levels of I L-6 were expressed in 8 (21%) of 39 AML patients and in 2 (29%) of 7 A MLL patients, whereas in ALL, the expression of IL-6 was almost neglig ible. IL-6R was expressed in all patients with AML and AMLL, whereas o nly half of ALL patients expressed low levels of IL-6R as compared wit h those with AML and AMLL. However, gp130 was ubiquitously expressed i n all the leukemia patients, and there was no significant difference i n gp130 expression among AML, ALL, and AMLL. Significant correlation w as observed between the expression of IL-6R and gp130 in AML. When tes ted for in vitro response to IL-6, the leukemic cells from 3 of 7 AML, none of 3 ALL, and both of 2 AMLL patients significantly responded to IL-6, showing the correlation between the expression levels of IL-6R and gp130 and the responsiveness of leukemic cells to IL-6. These resu lts showed that quantitation of IL-6R and gp130 expression by reverse transcriptase-polymerase chain reaction is useful for the rapid predic tion of the responsiveness of leukemic cells to IL-6, especially in ca ses of administration of IL-6. (C) 1994 by The American Society of Hem atology.