Extracellular CD30 and ADAM10/17 Regulate Brentuximab Vedotin-Induced Cell Death in an Adult T-Cell Leukemia Cell Line

Adult T-cell leukemia/lymphoma (ATL) is a human T-cell leukemia virus 1 (HTLV-1)-induced malignancy of mature T lymphocytes with poor outcomes. Brentuximab vedotin (BV), which is an anti-CD30 antibody conjugated with monomethyl auristatin E, is included in the treatment of CD30-positive ATL, but there is no useful therapeutic marker for BV. Soluble CD30 (sCD30) in serum is increased in aggressive-type ATL at diagnosis, but the effects of extracellular CD30 on BV-induced cell death in ATL remain unclear. Similarly, a disintegrin and metalloproteinase (ADAM) 10 and 17 have CD30 sheddase activity in anaplastic large cell lymphoma, but this activity is unknown in ATL. The present study showed that sCD30 concentrations were related to BV activity in ATL-related cell lines. Extracellular vesicles (EVs) such as exosomes containing CD30 also inhibited BV activity. Additionally, the knockdown of ADAM10/17 significantly reduced sCD30 concentrations with increased cell death by BV. Our results suggest that ADAM10/17 are involved in sCD30 production in ATL. Moreover, endogenous extracellular CD30, such as sCD30 shed by ADAM10/17, and CD30-positive EVs may be responsible for the BV-induced cell death. Correctively, extracellular CD30 concentrations, including EV, may be useful as biomarkers for BV therapy in ATL.