Figure 5.

(a) Western blot analysis of wild‐type lymphoblastoid cells (WT) and cells carrying ataxia telangiectasia mutated (ATM) heterogenous single nucleotide polymorphism with reduced ATM expression (L2). Extracts from LCLs probed with antibodies to topoisomerase II alpha (TOP2A), and α‐tubulin. Right panel, histograms of each cell cycle distribution. (b) Apoptosis percentages after etoposide treatment. The WT, L2, and ataxia telangiectasia (AT) cells were treated with 10 μM etoposide for 16 h and subjected flow cytometric analysis. Apoptosis percentages were measured by counting subdiploid fractions after staining with propidium iodide. The results were obtained after three independent experiments. (c) MLL rearrangements were analyzed by long distance inverted PCR. Arrow, rearranged bands; asterisk, germline bands; SM, size marker.