Fig. 5.
The chemosensitization of B-lymphoma cells by Rituxan homodimers.
The cytotoxic effect of doxorubicin alone (▾) or doxorubicin in combination with Rituxan monomers (●) or homodimers (○) at 20 μg/mL was determined by means of 3 cell lines: DHL-4 (panel A), Namalwa (panel B), and Namalwa/MDR1 (panel C). Cells at 5 × 104 cells per well in 100 μL were plated in 96-well plates, and various concentrations of doxorubicin (1 to 70 nM) alone or in combination with a constant noncytotoxic concentration of Rituxan (20 μg/mL) were added in 100 μL media in triplicate wells. The plates were incubated for 24 hours, pulsed with3H-thymidine, and then harvested. Rituxan alone (data not shown) had no effect. This is 1 of 2 experiments carried out.