Reduced expression of FLIPSHORT in bone marrow of low risk myelodysplastic syndrome

Apoptosis is dysregulated in patients with myelodysplastic syndrome (MDS) and acute myelogenous leukaemia (AML). FLIP (FLICE (FAS-associated death-domain-like IL-1beta-converting enzyme)-inhibitory protein) has been described as an anti-apoptotic protein. Here, we characterize the expression level of FLIPLONG and FLIPSHORT mRNA in bone marrow aspirates from 61 patients diagnosed with MDS or AML. FLIPSHORT mRNA expression was significantly lower in low risk MDS, compared to high risk MDS, according to FAB classification (RA/RARS versus RAEB/RAEBt, P = 0.0127) and IPSS (low risk/intermediate-1 versus intermediate-2/high risk, P = 0.0345). Furthermore, FLIPSHORT mRNA expression was significantly lower in low risk MDS, compared to MDS-AML/AML de novo (P = 0.0006), according to FAB classification. FLIPLONG expression did not differ between these groups. Increased levels of FLIPSHORT in RAEB and AML may be related to apoptosis resistance in these diseases and to MDS progression.