Overexpression of the bcl-2 oncogene in the mouse pre-B cell line SPGM-1 protects from apoptosis, but does not affect blocked B-lineage differentiation and lineage switch towards macrophage like cells

Abstract

The CD5+ mouse pre-B cell line SPGM-1 is able to undergo lineage conversion towards a macrophage like cell type. Although one of the κ-light chain alleles is rearranged in V-Jκ4 configuration, no protein is expressed nor could the expression be induced. Infection with and expression of the human bcl-2 gene protected SPGM-1 cells from apoptosis, allowing the rearrangement of their second κ-allele in V-JκS configuration. mRNA transcripts of the V-Jκ regions were detected only in SPGM-1 × bcl-2 cells, but not in SPGM-1, while κ-light chain protein was not found in any of the cell lines. The myeloid differentiation potential of SPGM-1 cells was not affected by overexpression of the human bcl-2 g..