Targeting autophagy and beyond:Deconvoluting the complexity of Beclin-1 from biological function to cancer therapy

AbstracBteclin-1 is the firstly-identified mammalian protein of the autophagy machinery,which functions as a molecular scaffold for the assembly of PI3KC3(class II phosphatidylinositol 3 kinase)complex,thus controlling autophagy induction and other cellular trafficking events.Notably,there is mounting evidence establishing the implications of Beclin-1 in diverse tumorigenesis processes,including tumor suppression and progression as well as resistance to cancer therapeutics and CSC(cancer stem-like cell)maintenance.More importantly,Beclin-1 has been confirmed as a potential target for the treatment of multiple cancers.In this review,we provide a comprehensive survey of the structure,functions,and regulations of Beclin-1,and we discuss recent advances in understanding the controversial roles of Beclin-1 in oncology.Moreover,we focus on summarizing the targeted Beclin-1-regulating strategies in cancer therapy,providing novel insights into a promising strategy for regulating Beclin-1 to improvecancer therapeutics in thefuture.

New insight into the oncogenic mechanism of the retroviral oncoprotein Tax

Human T cell leukemia virus type 1(HTLV-1),an etio-logical factor that causes adult T cell leukemia and lym-phoma(ATL),infects over 20 million people worldwide.About 1 million of HTLV-1-infected patients develop ATL,a highly aggressive non-Hodgkin's lymphoma without an effective therapy.The pX region of the HTLV-1 viral genome encodes an oncogenic protein,Tax,which plays a central role in transforming CD4+ T lymphocytes by deregulating oncogenic signaling pathways and promoting cell cycle progression.Expression of Tax following viral entry is critical for promoting survival and proliferation of human T cells and is required for initiation of oncogenesis.Tax exhibits diverse functions in host cells,and this oncoprotein primarily targets IκB kinase complex in the cytoplasm,resulting in persistent activation of NF-κB and upregulation of its responsive gene expressions that are crucial for T cell survival and cell cycle progression.We here review recent advances for the pathological roles of Tax in modulating IκB kinase activity.We also discuss our recent observation that Tax connects the IκB kinase complex to autophagy pathways.Understanding Tax-mediated pathogenesis will provide insights into development of new therapeutics in controlling HTLV-1-associated diseases.