Effect of pre- and post-treatment with either Mapatumumab or Lexatumumab on cisplatin cytotoxicity. A. Effects of pre- and post-treatment with Mapatumumab (Mapa) on cisplatin cytotoxicity in H28 cells. (X) H28 cells were pre-treated with 0.1 μg/ml Mapatumumab and incubated for various times (0–24 h) followed by treatment with 4.0 μM cisplatin and responses were determined by MTT assay after 48 h. (o) H28 cells were treated with 4.0 μM cisplatin and post-treated with 0.1 μg/ml Mapatumumab after various times (0–24 h). Responses were determined by MTT assay after 48 h. B. Effect of pre- and post-treatment with Lexatumumab (Lexa) on cisplatin cytotoxicity in H28 cells. Experiments were performed as described in A, except that Lexatumumab at a concentration of 0.4 μg/ml was used instead of Mapatumumab. Absorbance values obtained with untreated cells maintained under identical conditions were taken as 100%. Data represent means of three independent experiments and bars indicate standard deviations.