Table 1.

Summary of cell-surface CD20 expression and its inhibition by antioxidants

Treatment	CD20 expression (fold change)
	Raji (at 12 h)	Daudi (at 20 h)
Control	1	1
Vitamin C (1 μg/ml, 1 h)	1	1
Amifostine (0.1 μg/ml, 1 h)	1	1
H2O2 (1 μM)	1.65±0.14*	1.58±0.11*
Vitamin C (1 μg/ml, 1 h)+H2O2 (1 μM)	1.13±0.06#	1.1±0.08#
Radiation (0.5 Gy)	2.2±0.25*	1.8±0.3*
Vitamin C (1 μg/ml, 1 h)+radiation (0.5 Gy)	2.25±0.35*	2.1±0.2*
Amifostine+H2O2	1.1±0.073##	0.94±0.08##
Amifostine+radiation (0.5 Gy)	0.9±0.2###	1.2±0.15###

Maximum CD20 expression varies from 12 to 20 h, depending on the cell type. Modulation of H₂O₂-or radiation-(0.5 Gy) induced CD20 expression using antioxidants (amifostine or vitamin C) was measured as described under Materials and methods. Cell-surface CD20 expression was measured by flow cytometry at 12 and 20 h for Raji and Daudi cells, respectively. All results are from three independent experiments and expressed as fold change in expression of CD20±SD.

^*p<0.05 for control vs radiation or H₂O₂.

^#p<0.05 for H₂O₂ vs vitamin C+H₂O₂.

^##p<0.5 for H₂O₂ vs amifostine+H₂O₂.

^###p<0.05 for 0.5 Gy vs amifostine+0.5 Gy.