p53 Aberrations do not predict individual response to fludarabine in patients with B-cell chronic lymphocytic leukaemia in advanced stages Rai III/IV

Abnormalities of p53 have been associated with short survival and non-response to therapy in chronic lymphocytic leukaemia (CLL). We have evaluated the rate of response to fludarabine as first-line therapy in 54 patients with advanced stage CLL, analysing the cytogenetic profile, aberrations in p53, including the methylation status of its promoter, and the immunoglobulin heavy-chain variable-region (IGVH) mutation status. According to the advanced stage of the disease in this series, 75% of patients presented genetic aberrations associated with poor prognosis: del(17p) and/or del(11q), and no-mutated IGVH genes. Ten patients (18.5%) had methylation in the promoter region of p53. Eighty-three per cent of patients treated achieved a response, with a high rate of complete remission (47.6%). Although we found a significant correlation between failures and the presence of p53 aberrations (P = 0.0065), either with methylation (P = 0.018) or deletion (P = 0.015), 64% of the patients with aberrations in this gene responded to treatment (11/17), suggesting that fludarabine induces high remission rates, even in these patients. This is the first time that the significance of p53 promoter methylation status is described in this pathology, and our data support that this epigenetic phenomenon could be involved in the pathogenesis and clinical evolution of CLL

NUP98 is fused to HOXA9 in a variant complex t(7;11;13;17) in a patient with AML-M2

The t(7;11)(p15;p15.4) has been reported to fuse the NUP98 gene (11p15), a component of the nuclear pore complex, with the class-1 homeobox gene HOXA9 at 7p15. This translocation has been associated with myeloid leukemias, predominantly acute myeloid leukemia (AML) M2 subtype with trilineage myelodysplastic features, and with a poor prognosis. The derived fusion protein retains the FG repeat motif of NUP98 N-terminus and the homeodomain shared by the HOX genes, acting as an oncogenic transcription factor critical for leukemogenesis. We report here a new complex t(7;11)-variant, i.e., t(7;11;13;17)(p15;p15;p?;p1?2) in a patient with AML-M2 and poor prognosis. The NUP98-HOXA9 fusion transcript was detected by RT-PCR, suggesting its role in the malignant transformation as it has been postulated for other t(7;11)-associated leukemias. No other fusion transcripts involving the NUP98 or HOXA9 genes were present, although other mechanisms involving several genes on chromosomes 13 and 17 may also be involved. To our knowledge, this is the first t(7;11) variant involving NUP98 described in hematological malignancies