TRAIL-Non-Apoptotic Signalling

Abstract

TNF-related apoptosis-inducing ligand (TRAIL or Apo2 or TNFSF10) belongs to the TNF superfamily. When bound to its agonistic receptors, TRAIL can induce apoptosis in tumour cells, while sparing healthy cells. This tumour selectivity prompted, over the last three decades, many studies aiming at evaluating the anti-tumoral potential of TRAIL or its derivatives. Although most of these attempts have failed, so far, novel formulations are still being evaluated. Yet, emerging evidence indicates that TRAIL can also trigger, on the other hand, a non-canonical signal transduction pathway that is likely to be detrimental for its use in oncology. Likewise, increasing studies suggest that TRAIL can induce, through Death receptor 5 (DR5) in some circumstances, tumour cell motility, potentially leading to and contributing to tumour metastasis. While the pro-apoptotic signal transduction machinery of TRAIL is well known from a mechanistic point of view, that of the non-canonical pathway is less understood. We are reviewing here the current state of knowledge of TRAIL non-canonical signalling.