c-FLIP/Ku70 complex; A potential molecular target for apoptosis induction in hepatocellular carcinoma

Abstract

Hepatocellular carcinoma (HCC) is one of the most lethal malignancies worldwide and the most common form of liver cancer. Despite global efforts toward early diagnosis and effective treatments, HCC is often diagnosed at advanced stages, where conventional therapies frequently lead to resistance and/or high recurrence rates. Therefore, novel biomarkers and promising medications are urgently required. Epi-drugs, or epigenetic-based medicines, have recently emerged as a promising therapeutic modality. Since the epigenome of the cancer cells is always dysregulated and this is followed by apoptosis-resistance, reprogramming the epigenome of cancer cells by epi-drugs (such as HDAC inhibitors (HDACis), and DNMT inhibitors (DNMTis)) could be an alternative approach to use in concert with established treatment protocols. C-FLIP, an anti-apoptotic protein, and Ku70, a member of the DNA repair system, bind together and make a cytoplasmic complex in certain cancers and induce resistance to apoptosis. Many epi-drugs, such as HDACis, can dissociate this complex through Ku70 acetylation and activate cellular apoptosis. The novel compounds for dissociating this complex could provide an innovative insight into molecular targeted HCC treatments. In this review, we address the innovative therapeutic potential of targeting c-FLIP/Ku70 complex by epi-drugs, particularly HDACis, to overcome apoptosis resistance of HCC cells. This review will cover the mechanisms by which the c-FLIP/Ku70 complex facilitates cancer cell survival, the impact of epigenetic alterations on the complex dissociation, and highlight HDACis potential in combination therapies, biomarker developments and mechanistic overviews. This review highlights c-FLIP ubiquitination and Ku70 acetylation levels as diagnostic and prognostic tools in HCC management.