SENSITIVITY TO DEXAMETHASONE AND ABSENCE OF BCL-2 PROTEIN IN BURKITTS-LYMPHOMA CELL-LINE (BLACK93) DERIVED FROM A PATIENT WITH ACUTE TUMOR LYSIS SYNDROME - COMPARATIVE-STUDY WITH OTHER BL AND NON-BL LINES

An Epstein-Barr virus (EBV)-negative Burkitt's lymphoma (BL) cell line , designated Black93, was established in culture from a patient who de veloped acute tumor lysis syndrome (ATLS). Growth inhibition in vitro by dexamethasone (DXM) and the expression of bcl-2 protein (Bcl-2) wer e investigated in Black93 and 17 other cell fines derived from EBV-neg ative or -positive BL, pre-B acute lymphoblastic leukemia (ALL), folli cular lymphoma (FL), and EBV-positive lymphoblastoid cell lines of nor mal B cell origin (B-LCL), assuming an inherent susceptibility of Blac k93 to cell death, The most marked growth inhibition by DXM was observ ed in Black93, two other BL, two pre-B-ALL and two FL lines. The other cell lines were less sensitive or were resistant. DNA extracted from the Black93 cells treated with DXM showed a ladder of oligo-nucleosoma l DNA on electrophoresis. On testing of fixed smears by indirect immun ofluorescence, bcl-2 protein (Bcl-2) was undetectable in Black93 and t hree BL lines but was detected in all the other cell lines at varying intensity. Western blot analysis showed mostly the same results. in th e BL lines, the most DXM-sensitive cell lines lacked Bcl-2 expression, and the DXM-resistant cell lines always expressed Bcl-2. While none o f the DXM-resistant cell lines lacked Bcl-2 expression, several pre-B or FL lines that expessed Bcl-2 were sensitive to DXM. Black93 is the first reported cell line established from a patient with ATLS. The pos itive sensitivity to DXM and the lack of Bcl-2 expression observed in Black93 are a major characteristic exhibited frequently by BL lines an d, probably, by fresh BL cells. These properties may contribute to the precipitation of ATLS.