LMP1 expression and tumorigenicity of BL30 and BL41 cell lines. (A) Western blot analysis of LMP1 expression in the BL30 and BL41 cell lines infected with P3HR-1 or B95-8 EBV. Cell extracts from 2 × 10⁵ cell equivalents were electrophoresed through 8% Tris-glycine gels, transferred onto nylon membranes, and probed with a murine MoAb to LMP1 (S12). (B) Growth curves of tumors induced by subcutaneous inoculation of the EBV⁻ and EBV-converted BL30 and BL41 cell lines. Each data point represents the mean tumor size of all mice in each group (5 to 10 mice per group). Mice injected with parental or P3HR1-converted cell lines were killed when the tumors had reached large sizes and impaired animal mobility. (○), Parental; (□), P3HR-1; (▵), B95-8.