Comparison of cytotoxic activity of gossypol and apogossypol against cultured murine B cells from transgenic mice: Bcl-2 versus Bcl-2/TRAF2ΔN. Splenocytes from age- and sex-matched Bcl-2–transgenic mice (top; n = 3 pairs) and Bcl-2/TRAF2ΔN double-transgenic mice (bottom; n = 2 pairs) were cultured at 106 cells/mL for 18 hours in the absence (vehicle control) or presence of various concentrations (log-scale) of gossypol (closed symbols) or apogossypol (open symbols). Percentage viability was determined by staining with FITC–annexin V/PI, scoring viable cells as annexin V negative/PI negative. Immunoblot analysis (bottom right) was performed using whole-cell lysates from splenocytes of Bcl-2–transgenic (n = 2) and Bcl-2/TRAF2ΔN–transgenic (n = 3) mice, normalized for protein content (50 μg/lane). Blots were probed with antibodies recognizing murine Bfl-1 ortholog A1 (∼ 15-kDa band, probably corresponding to A1c isoform), human Bcl-2, and beta-actin.
