Wortmannin induces apoptosis in NPM-ALK–transformed cells.

Parental Ba/F3 (A), NPM-ALK–transformed Ba/F3 (B), and the ALCL cell line JB6 (C) were incubated with 300 nmol/L wortmannin (░) or DMSO as control (■) for 3 days, with daily addition of wortmannin and DMSO. The Ba/F3 cells were cultured with murine IL-3 as growth factor. The exposed 3′-OH ends of DNA fragments generated in response to apoptotic signals were FITC-fluorescein–labeled by terminal deoxynucleotidyl transferase (TdT). Results were evaluated using a flow cytometer. The expression of NPM-ALK in cells established from patients with LCAL (JB6, Karpas299, SUP-M2, SU-DHL1) and in parental Ba/F3 cells and Ba/F3 cells expressing NPM-ALK was shown by anti-ALK immunoblot (D).