EXPRESSION OF SOME APOPTOTIC INHIBITORS IN CASES OF ADULT ACUTE MYELOID LEUKEMIA

Abstract

The expression of antiapoptotic genes; bcl-2, Survivin and Aven was examined in Egyptian cases of acute myeloid leukemia (AML). Flow cytometry (FCM) was used to detect the expression of bcl-2 and reverse transcriptase-PCR was used to examine the expression of Survivin and Aven mRNA. Bcl-2 was highly expressed in all cases of AML than controls (p< 0.001). The percentage of bcl-2+ cells was significantly higher in M1 (60%), M2 (54%) and M3 (56%) than in M4 (43%) and M5 (40%) subtypes (p=0.01). The AML patients showed expression of Survivin mRNA but no expression of Aven mRNA was observed. Out of 30 patients, 23 (76.6%) showed detectable levels of Survivin expression. The ratio between Survivin mRNA and beta-Actin mRNA was analyzed quantitatively in AML samples showing expression bands. Different expression levels of Survivin mRNA could be observed between different FAB subgroups. M1, M4 and M5 AML had a relatively higher expression level of Survivin mRNA (range: 0.56-0.81) than M2 and M3 patients (range:0.04-0.1). There was also a significant correlation between Survivin expression and PB blast % in cases of M5 subtype of patients (P=0.02). The Survivin-positive AML cases showed a higher percentage of bcl-2 expression and a significantly higher Bcl-2 MFI (mean fluorescence index) in comparison with Survivin-negative ones (p= 0.01). Our findings suggest that over-expression of both apoptotic inhibitors Bcl-2 and Survivin might be involved in AML pathogenesis