Identification of two U937 cell sublines exhibiting different patterns of response to tumour necrosis factor

The monocytic cell line U937 is a frequently used model in studies on the c ytotoxic effect of tumour necrosis factor (TNF), Two sublines of this cell line, termed U937, and U937,,, revealing different patterns of response to this cytokine, have been identified, The U937, cells, similarly to the cell s obtained from ATCC, were resistant to the cytotoxic action of TNF in the absence of the protein-synthesis blocker cycloheximide (CHX). The U937,, ce lls, however, were sensitive to the cytotoxic action of TNF both in the pre sence and absence of cycloheximide. Genetic analysis of the U937 sublines c onfirmed their common origin. The described U937 sublines may be useful mod els for analysis of the mechanisms of response to TNF, Additionally, our ob servation underscores the variability of the U937 cell line, which is descr ibed by most authors as a TNF-sensitive line. (C) 2001 Academic Press.