Resistance of Sézary Cells to TNF-α-Induced Apoptosis Is Mediated in Part by a Loss of TNFR1 and a High Level of the IER3 Expression

摘要

Failure to execute an apoptotic program is one of the critical steps and a common mechanism promoting tumorogenesis. Immediate early responsive gene 3 (IER3) has been shown to be upregulated in several cancers. IER3 is a stress induced gene, which upregulation leads to reduction in production of reactive oxygen species (ROS) protecting malignant cells from apoptosis. We observed that malignant lymphocytes from patients with Sézary syndrome (SzS) were resistant to pro-apoptotic dose of tumor necrosis factor-α (TNF-α). The aim of this study was to investigate the role of IER3 in the mechanism of such resistance. CD4+ CD26− lymphocytes from the peripheral blood of patients with SzS and healthy controls were negatively selected using CD4 and CD26 magnetic beads and analyzed for expression of TNFR1, TNFR2, IER3 expression, and ROS production in response to TNF-α at an apoptotic dose. Sézary cells with a higher level of IER3 expression retained their viability to TNF-α. IER3 upregulation correlated with a decrease level of intracellular ROS and low TNFR1 expression on malignant cells. Targeting IER3 could be of interest for the development of future therapeutic strategies for patients with SzS.