A histone deacetylase inhibitor, azelaic bishydroxamic acid, shows cytotoxicity on Epstein-Barr virus transformed B-cell lines: a potential therapy for posttransplant lymphoproliferative disease

BACKGROUND: Posttransplant lymphoproliferative disease (PTLD), driven by the presence of Epstein-Barr virus (EBV), is becoming an increasingly important clinical problem after solid organ transplantation. The use of immunosuppressive therapy leads to the inhibition of the cytotoxic T cells that normally control the EBV latently infected B cells. The prognosis for many patients with PTLD is poor, and the optimal treatment strategy is not well defined. METHOD: This study investigates the use of a histone deacetylase inhibitor, azelaic bishydroxamic acid (ABHA), for its ability to effectively kill EBV-transformed lymphoblastoid cell lines. RESULTS: In vitro treatment of lymphoblastoid cell lines with ABHA showed that they were effectively killed by low doses of the drug (ID50 2-5 microg/ml) within 48 hr. As well as being effective against polyclonal B-cell lines, ABHA was also shown to be toxic to seven of eight clonal Burkitt's lymphoma cell lines, indicating that the drug may also be useful in the treatment of late-occurring clonal PTLD. In addition, ABHA treatment did not induce EBV replication or affect EBV latent gene expression. CONCLUSION: These studies suggest that ABHA effectively kills both polyclonal and clonal B-cell lines and has potential in the treatment of PTLD.