Dehydroxymethylepoxyquinomicin (DHMEQ) therapy reduces tumor formation in mice inoculated with Tax-deficient adult T-cell leukemia-derived cell lines

Adult T-cell leukemia (ATL) is an aggressive neoplasm caused by human T-cell leukemia virus type I (HTLV-I), which induces nuclear factor-κB (NF-κB), a molecule central to the ensuing neoplasia. The NF-κB inhibitor dehydroxymethylepoxyquinomicin (DHMEQ) has been shown to inhibit NF-κB activation in Tax-expressing HTLV-I-infected cells. In this study, we used NOD/SCID β2-microglobulinnull mice to show that intraperitoneal inoculation with Tax-deficient ATL cell lines caused rapid death, whereas DHMEQ-treated mice survived. Furthermore, DHMEQ treatment after subcutaneous inoculation inhibited the growth of transplanted ATL cells. These results demonstrate that DHMEQ has therapeutic efficacy on ATL cells, regardless of Tax expression.