Camptothecin and UV sensitivity and Rad51 focus formation in human lymphoblasts. (A) FA-D1 lymphoblasts with a defect in FANCD1/BRCA2 are as sensitive to growth inhibition by camptothecin as EUFA867 lymphoblasts. (B) FA-N lymphoblasts with a defect in FANCN/PALB2 are as sensitive to growth inhibition by camptothecin as EUFA867 lymphoblasts. EUFA1341R is a MMC-resistant reverted derivative of EUFA1341 lymphoblasts. (C) EUFA867 lymphoblasts are sensitive to UV. Lymphoblasts were exposed to different doses of UVC light and cell growth was compared with untreated cells by cell counting. Lymphoblasts of xeroderma pigmentosum patient XP3BE were used as a positive control. Results show mean values of at least 5 experiments with SEM. (D) Normal Rad51 focus formation in EUFA867 lymphoblasts. Kinetics of Rad51 foci formation in response to x-ray irradiation (12 Gy) or MMC treatment (2.4 μg/mL for 1 hour) analyzed 7 and 24 hours after treatment. A cell with more than 5 distinct foci in the nucleus was considered positive. Results show the mean values of at least 2 experiments with standard error of the mean.