Diverse properties of human t(8;14) neoplasms: [1] ATLS and absence of BCL-2 [2] modulation of RAG-1 expression with S-Ig ligation.

An EBV(-) BL (Burkitt lymphoma) line (Black93), established from a patient exhibiting glucocorticoid-induced ATLS (acute tumor lysis syndrome), was highly sensitive to dexamethazone (DX) in vitro in the studies including 18 lymphoid cell lines (10 BL lines). In the BL lines, the highly sensitive ones always lacked Bcl-2(bcl-2 protein), while the DX resistant ones expressed Bcl-2. Black93 is the first BL cell-line derived from a ATLS patient, proving that cell lines can be established in vitro from ATLS patients. Since some pre-B ALL lines expressing Bcl-2 were DX-sensitive, the relationship between Bcl-2 and DX-sensitivity is not straight-forward. In the BL cells, however, the absence of Bcl-2 appears to be responsible for the DX-sensitivity. The DX-sensitivity and the absence of Bcl-2 is a major characteristic carried by t(8;14) neoplasms. In addition, there may be a stage of B-lineage differentiation without Bcl-2. While rare BL cases have been reported to express TdT (terminal desoxynucleotidyl transferase), Tree92 is the first such line, expressing S-Ig(mu, lambda), TdT and RAG (recombination activating gene)-1. When surface mu is ligated with antibody, RAG-1 was suppressed in expression, indicating that the signal through S-Ig can modulate the expression of RAG-1 in the Tree92 cells. Chromosome translocation is known to be associated with a specific stage of differentiation. Such specific stage for t(8;14), however, is broad enough to cover S-Ig(+), TdT(+) and RAG-1(+) stage, too. The phenotypic classification of leukemia/lymphoma and the delineation of differentiation scheme of normal hematopoietic cells, are dependent on each other. The documentation of the properties such as DX-sensitivity, the absence of Bcl-2, the expression of RAG-1 and its modulation by the signal through S-Ig is an example in which the diverse properties of human t(8;14) neoplasms can contribute for delineating the differentiation scheme of normal hematopoietic cells more precisely.