Construction and characterization of a new TRAIL soluble form, active at picomolar concentrations

// Matias Eliseo Melendez 1 , Renato Jose Silva-Oliveira 1 , Anna Luiza Silva Almeida Vicente 1 , Lidia Maria Rebolho Batista Arantes 1 , Ana Carolina de Carvalho 1 , Alberto Luis Epstein 2 , Rui Manuel Reis 1, 3, 4 and Andre Lopes Carvalho 1 1 Molecular Oncology Research Center, Barretos Cancer Hospital, Barretos, Sao Paulo, Brazil 2 UMR1179, INSERM-UVSQ, Handicap Neuromusculaire, Biotherapie et Pharmacologie Appliquees, Universite de Versailles-Saint Quentin en Yvelines, Versailles, France 3 Life and Health Sciences Research Institute (ICVS), Health Sciences School, University of Minho, Braga, Portugal 4 ICVS/3B’s-PT Government Associate Laboratory, Braga/Guimaraes, Portugal Correspondence to: Andre Lopes Carvalho, email: carvalhoal@gmail.com Keywords: TRAIL; apoptosis; cancer treatment; amplicon vectors Received: August 12, 2016     Accepted: May 14, 2018     Published: June 05, 2018 ABSTRACT Apoptosis induction has emerged as a treatment option for anticancer therapy. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a type II transmembrane protein, is a potent and specific pro-apoptotic protein ligand, which activates the extrinsic apoptosis pathway of the cell death receptors. Here we describe the construction and characterization of a new soluble TRAIL, sfTRAIL, stabilized with the trimerization Foldon domain from the Fibritin protein of the bacteriophage T4. Supernatants of 0.22 μM-filtered supernatants were produced in Vero-transduced cells with HSV1-derived viral amplicon vectors. Experiments were undertaken in two known TRAIL-sensitive (U373 and MDA.MB.231) and two TRAIL-resistant (MCF7 and A549) cell lines, to determine (i) whether the sfTRAIL protein is synthetized and, (ii) whether sfTRAIL could induce receptor-mediated apoptosis. Our results showed that sfTRAIL was able to induce apoptosis at concentrations as low as 1899.29 pg/mL (27.71 pM), independently of caspase-9 activation, and reduction in cell viability at 998.73 fM.