Fig. 1.

TDP2 suppresses TOP2-induced genome instability in human cells. a Micronuclei (MN, left) and nucleoplasmic bridges (NB, right) were quantified in control and TDP2 patient lymphoblastoid cells following continuous treatment (24 h) with the indicated concentration of etoposide. Data are the average (±s.e.m.) of a minimum of 300 cells from three independent experiments. Statistical significance was determined by T-test (*P < 0.05, **P < 0.01). b M-FISH karyotyping of control and TDP2 patient lymphoblastoid cells following continuous treatment with 50 nM etoposide for 20 h. Left, example of a patient metaphase depicting a chromatid break on Chr2 and a dicentric chromosome involving Chr3 and Chr4 (white asterisks). Right, quantification of abnormal metaphases by M-FISH in control and TDP2 patient lymphoblastoid cells. Statistical significance was determined by GLM ANOVA (***P < 0.005, NS, not significant). c Distribution of chromosome aberrations per abnormal metaphase. The total number of events (chromosome and chromatid exchanges/breaks) were counted in each abnormal metaphase (5 or more events per cell were pooled as > 5). Statistical significance was determined by ANOVA (*P < 0.05, ***P < 0.005)