FLIP as a therapeutic target in cancer. (27th June 2018)

• Record Type: Journal Article
• Authors: Humphreys, Luke; Espona‐Fiedler, Margarita; Longley, Daniel B.
• Is Part Of: FEBS journal. Volume 285:Number 22(2018)
• Page Start: 4104
• Page End: 4123
• Publication Date: 2018-06-27
• Subjects: apoptosis -- autophagy -- cancer -- Cflar -- DISC -- FLIP -- necroptosis -- resistance; Biochemistry -- Periodicals; Molecular biology -- Periodicals; Pathology, Molecular -- Periodicals; 572
• DOI: 10.1111/febs.14523
• Languages: English
• ISSNs: 1742-464X

Abstract

Abstract : One of the classic hallmarks of cancer is disruption of cell death signalling. Inhibition of cell death promotes tumour growth and metastasis, causes resistance to chemo‐ and radiotherapies as well as targeted agents, and is frequently due to overexpression of antiapoptotic proteins rather than loss of pro‐apoptotic effectors. FLIP is a major apoptosis‐regulatory protein frequently overexpressed in solid and haematological cancers, in which its high expression is often correlated with poor prognosis. FLIP, which is expressed as long (FLIP(L)) and short (FLIP(S)) splice forms, achieves its cell death regulatory functions by binding to FADD, a critical adaptor protein which links FLIP to the apical caspase in the extrinsic apoptotic pathway, caspase‐8, in a number of cell death regulating complexes, such as the death‐inducing signalling complexes (DISCs) formed by death receptors. FLIP also plays a key role (together with caspase‐8) in regulating another form of cell death termed programmed necrosis or 'necroptosis', as well as in other key cellular processes that impact cell survival, including autophagy. In addition, FLIP impacts activation of the intrinsic mitochondrial‐mediated apoptotic pathway by regulating caspase‐8‐mediated activation of the pro‐apoptotic Bcl‐2 family member Bid. It has been demonstrated that FLIP can not only inhibit death receptor‐mediated apoptosis, but also cell death induced by a range of clinically relevant chemotherapeutic and targeted agents as well as ionizing radiation. More recently, key roles for FLIP in promoting the survival of immunosuppressive tumour‐promoting immune cells have been discovered. Thus, FLIP is of significant interest as an anticancer therapeutic target. In this article, we review FLIP's biology and potential ways of targeting this important tumour and immune cell death regulator. Abstract : FLIP is a key regulator of apoptosis through its ability to regulate procaspase‐8 dimerization, processing and activation. In addition, FLIP is involved in other critical cellular processes such as autophagy and necroptosis. Here, we provide an up‐to‐date review on the function and regulation of FLIP and discuss strategies for therapeutic targeting of this important cell death regulator in cancer.