Development of TrxR1 inhibitors yielded six new Ugi-Michael acceptors with anticancer effects in neuroblastoma cells

Abstract

Introduction: Cancer cells have high expression of thioredoxin (Trx) system proteins - Tx and thioredoxin reductase (TrxR) [1,2]. lnhibition of Trx system is a perspective target of chemotherapy development [3,4]. Here we describe biological effects of six new Ugi-Michael acceptors (UMAs), potential TrxR1 inhibitors, in human neuroblastoma cell line (SH-SY5Y) and normal human keratinocytes (HaCaT). Materials & Methods: lnhibitory potential of UMAs was assessed by TxR1 and insulin assay. Cytotoxicity was determined by MTT assay. Flow cytometry was used to assess reactive oxygen and nitrogen species (RONS) levels by DHE and DHR staining and to analyze cell death by AV/PI labeling. Reults: TrxR1 and insulin assay proved that six novel UMAs are inhibitors of TrxR1 and Trx system. The inhibitors of TrxR1 showed cytotoxic effect in both cell lines. However, UMAs evoked increase in RONS only in neuroblastoma cells, but not in keratinocytes. These compounds also induced necrotic cell death in both cell lines. lmportantly, cell death induction was more pronounced in SH-SY5Y cells and in accordance with observed elevation of RONS levels.