Cell fusion is not involved in the generation of giant cells in the Hodgkin-Reed Sternberg cell line L1236

The mechanism of multinucleated cell formation in Hodgkin's disease has not yet been elucidated. We asked whether the giant multinucleated cells of th e H-RS cell line L1236 develop via fusion of the predominant smaller cells. As a positive control for the fusion assay, human B cells from the B-cell lymphoma cell line BJA-B were split into two fractions, stained with the fl uorochromes CMTMR and CMFDA, respectively, and fused using the polyethylene glycol 1500 cell hybridization protocol. Double-stained cells Indicating f usion of BJA-B cells were detectable for up to 5 days. In parallel, L1236 c ells were split into two fractions, stained with the fluorochromes, and mix ed. No double-stained L1236 cells were detected. The same result was obtain ed when using FACS-sorted small mononuclear L1236 cells. It is thus conclud ed that the large multinucleated cells of the monoclonal H-RS cell line L12 36 have emerged by endomitosis rather than by spontaneous cell fusion. Am. J. Hematol. 67:6-9. (C) 2001 Wiley-Liss, Inc.