The expression of histone deacetylase 4 is associated with prednisone poor-response in childhood acute lymphoblastic leukemia

Abstract This study aimed at the identification of histone deacetylase (HDAC) isoforms relevant for childhood acute lymphoblastic leukemia (ALL). Expression of HDAC1-11 was determined in 93 primary ALL and eight healthy donor samples. HDAC1 , HDAC2 and HDAC8 showed significantly higher expressions in ALL samples. Correlation analysis of HDAC expression with clinicopathological parameters revealed that high HDAC1 , HDAC2 , HDAC4 and HDAC11 levels were significantly associated with unfavorable prognostic factors. Particularly, high HDAC4 expression was associated with high initial leukocyte count, T cell ALL and prednisone poor-response. siRNA-mediated inhibition of HDAC4 sensitized a T-ALL cell line to etoposide-induced cell death. In conclusion, our data point to HDAC4 as drug target in childhood ALL, especially in prednisone poor-responders.