Interleukin-11 Gene Expression in Human Lymphoid Malignancy

Interleukin-11 (IL-11) has diverse biological effects in hematopoiesis has been shown to share important functions with IL-6. However, unlike IL-6, there has been little information about the expression of IL-11 in lymphoid malignancy. Using reverse transcriptase polymerase chain reaction, IL-11 transcript was found in a number of lymphoid cell lines. A high level of expression was found in follicular lymphoma cell line FL18, and this was also detectable by Northern blotting. When TPA/A23187 were added to the culture of bone marrow stromal cell line KM102, IL-11 transcripts were rapidly upregulated. In contrast, levels of IL-11 transcripts were not increased in FL18 even upon the stimulation. The addition of actinomycin D to the cultures showed that the half life of the transcripts was similar in both FL18 and KM102. This suggests that posttran scriptional processes might not be involved in the constitutive expression of FL18. The results of IL-11 bioassay and enzymed-linked immunosorbent assay showed that FL18 did not secrete biologically active IL-11 into the medium. IL-11 transcript was also found in lymphoma cells in patient with malignant lymphoma, but not in B and T lymphocytes from reactive hyperplasia. Our results indicate that IL-11 transcripts can sometimes be produced in the neoplastic transformation of lymphoid cells.