Formation of γH2AX foci in BMPCs. (A) γH2AX foci formation 2 to 48 hours after treatment with melphalan alone. Formation of γH2AX foci 2 to 48 hours after treatment of BMPCs from responders (B) or nonresponders (C) with melphalan in the presence or not of an inhibitor. NO INH, no inhibitor. R, responders; NR, nonresponders. (D) Total amounts of γH2AX foci, expressed as AUC, after treatment with melphalan in the presence or not of an inhibitor. The experiments shown were based on a minimum of 3 independent repeats and the data reported are the mean ± SD of all the patients analyzed. (E) Typical images showing the γH2AX staining at different time points after treatment of BMPCs from 1 representative responder (R) and 1 nonresponder (NR) with melphalan alone or in the presence of SCR7. Upper images, immunofluorescence antigen staining; bottom images, cell nuclei labeled with 4′,6-diamidino-2-phenylindole.