EXPRESSION OF EXOGENOUS NF-IL6 INDUCES APOPTOSIS IN SP2 0-AG14 MYELOMA CELLS/

NF-IL6 (or C/EBP beta) is a multifunctional transcription factor of th e C/EBP family. To study the effects of exogenous expression of NF-IL6 on the growth of cells of hematopoietic tumors, we infected SP2/0-Ag1 4 myeloma cells with pLXSN recombinant retrovirus harboring the NF-IL6 cDNA, We found that the transfected cells revealed changes typical of the apoptosis and finally died, The expression of NF-IL6 protein was shown by a ''supershift'' assay in the NF-IL6-transfected cells. In co ntrols, where cells were infected by the retroviral vector with a muta nt NF-IL6 coding region as well as the vector without insert, no sign for expression of NF-IL6 and apoptosis was observed, Therefore, our wo rk shows that the apoptosis of this myeloma cell line was induced by t he exogenous NF-IL6 expression. This is significantly different from t he apparent effects of NF-IL6 in leukemia cells and in fibroblasts, Th ese facts indicate that NF-IL6 exerts different functions in different cell types. We discuss possible mechanisms for the NF-IL6-induced apo ptosis.