Lentiviral-Mediated Beclin-1 Overexpression Inhibits Cell Proliferation and Induces Autophagy of Human Esophageal Carcinoma Eca109 Cell Xenograft in Nude Mice

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

Beclin-1 is the firstly-identified mammalian protein of the autophagy machinery, which functions as a molecular scaffold for the assembly of PI3KC3 (class III 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 improve cancer therapeutics in the future.

Modulation of autophagy by melatonin via sirtuins in stroke: From mechanisms to therapies

Sirtuins perform an important effect on the neural cell fate following stroke. Several mechanisms that have been correlated with stroke are oxidative stress, apoptosis, necrosis and autophagy. Autophagy is usually regarded as unitary of the neural cell survival mechanisms. Recently, the importance of the sirtuins effect on autophagy by antioxidant agents for stroke treatment mentioned in various studies. One of these agents is melatonin. Melatonin can modulate autophagy by changing on sirtuin pathways. Melatonin and its metabolites adjust various sirtuins pathways related to apoptosis, proliferation, metastases, autophagy and inflammation in case of stroke. In this review, we will discuss about the modulation of autophagy by melatonin via sirtuins in stroke.

TSPAN8 alleviates high glucose-induced apoptosis and autophagy via targeting mTORC2

TSPAN8 mediates signal transduction from extracellular cues and regulates cell development, activation, growth, and motility. However, whether TSPAN8 is involved in the progression of diabetic nephropathy (DN) remains unclear. This study aimed to explore the potential functional roles of TSPAN8 in regulating autophagy and apoptosis of HK-2 cells induced by high glucose (HG). RT-PCR and western blot analysis (WB) were employed to detect TSPAN8 levels in the blood samples of DN patients as well as in HG-induced HK-2 cells. Cell proliferation of HK-2 cells was examined by CCK-8 assay, and apoptosis was analyzed by flow cytometry. The functional role of TSPAN8 was evaluated by the transfection of TSPAN8 expression plasmid. Results showed that TSPAN8 level was significantly reduced in the blood samples of DN patients and HG-induced HK-2 cell lines. TSPAN8 overexpression rescued HG-induced apoptosis in HK-2 cells. TSPAN8 could form a complex with Rictor and mTORC2. TSPAN8 overexpression suppressed HG-induced autophagy in HK-2 cells, which was dependent on mTOR activity. In conclusion, the present study showed that TSPAN8 mitigates HG-induced autophagy and apoptosis in HK-2 cells, which may serve as candidate target for DN treatment.

Beclin1-mediated interplay between autophagy and apoptosis: New understanding

The definition for autophagy holds a 'single' meaning as a conserved cellular process that constitutes a recycling pathway for damaged organelles and long-lived proteins to maintain nutrient homeostasis and mediate quality control within the cell. But this process of autophagy may behave ambiguously depending on the physiological stress as the stress progresses in the cellular microenvironment; the 'single' meaning of the autophagy changes from the 'cytoplasmic turnover process' to 'tumor suppressive' and a farther extent, 'tumor promoter' process. In a tumorigenic state, the chemotherapy-mediated resistance and intolerance due to upregulated autophagy in cancer cells have become a significant concern. This concern has provided insight to the scientific community to enter into the arena of cross-talk between autophagy and apoptosis. Recent findings and ongoing research have provided insights on some of the key regulators of this cross-talk; one of them is Beclin1 and their involvement in the physiological and the pathophysiological processes; however, reconciliation of these two forms of death remains an arena to be explored extensively. This review sheds light on the interplay between autophagy and apoptosis, emphasizing one of the key players, Beclin1, and its importance in health and diseases.