Curcumin, a polyphenol extracted from Curcuma longa in 1815, has gained attention from scientists worldwide for its biological activities (e.g., antioxidant, anti-inflammatory, antimicrobial, antiviral), among which its anticancer potential has been the most described and still remains under investigation. The present review focuses on the cell signaling pathways involved in cancer development and proliferation, and which are targeted by curcumin. Curcumin has been reported to modulate growth factors, enzymes, transcription factors, kinase, inflammatory cytokines, and proapoptotic (by upregulation) and antiapoptotic (by downregulation) proteins. This polyphenol compound, alone or combined with other agents, could represent an effective drug for cancer therapy.

Curcumin and Cancer

https://digital.csic.es/bitstream/10261/135784/1/novel%20therapeutic%20targets.pdf

Sustained proliferation in cancer: Mechanisms and novel therapeutic targets

The beneficial role of curcumin on inflammation, diabetes and neurodegenerative disease: A recent update.

http://eprints.gla.ac.uk/102064/1/102064.pdf

Broad targeting of angiogenesis for cancer prevention and therapy

Autophagy (macroautophagy) is a highly conserved intracellular and lysosome-dependent degradation process in which autophagic substrates are enclosed and degraded by a double-membrane vesicular structure in a continuous and dynamic vesicle transport process. The Rab protein is a small GTPase that belongs to the Ras-like GTPase superfamily and regulates the vesicle traffic process. Numerous Rab proteins have been shown to be involved in various stages of autophagy. Rab1, Rab5, Rab7, Rab9A, Rab11, Rab23, Rab32, and Rab33B participate in autophagosome formation, whereas Rab9 is required in non-canonical autophagy. Rab7, Rab8B, and Rab24 have a key role in autophagosome maturation. Rab8A and Rab25 are also involved in autophagy, but their role is unknown. Here, we summarize new findings regarding the involvement of Rabs in autophagy and provide insights regarding future research on the mechanisms of autophagy regulation.

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Regulation of autophagy by the Rab GTPase network

Our study first proposed that curcumin could protect human endothelial cells from the damage caused by oxidative stress via autophagy. Furthermore, our results revealed that curcumin causes some novel cellular mechanisms that promote autophagy as a protective effect. Pretreatment with curcumin remarkably improves the survival of human umbilical vein endothelial cells (HUVECs) from H 2O 2-induced viability loss, which specifically evokes an autophagic response. Exposed to H 2O 2, curcumin-treated HUVECs upregulate the level of microtubule-associated protein 1 light chain 3-II (LC3-II), the number of autophagosomes, and the degradation of p62. We show that this compound promotes BECN1 expression and inhibits the phosphatidylinositol 3-kinase (PtdIns3K)-AKT-mechanistic target of rapamycin (MTOR) signaling pathway. Curcumin can also reverse FOXO1 (a mediator of autophagy) nuclear localization along with causing an elevated level of cytoplasmic acetylation of FOXO1 and the interaction of acetylated FOXO1 and ATG7, under the circumstance of oxidative stress. Additionally, knockdown of FOXO1 by shRNA inhibits not only the protective effects that curcumin induced, but the autophagic process, from the quantity of LC3-II to the expression of RAB7. These results suggest that curcumin induces autophagy, indicating that curcumin has the potential for use as an autophagic-related antioxidant for prevention and treatment of oxidative stress. These data uncover a brand new protective mechanism involving FOXO1 as having a critical role in regulating autophagy in HUVECs, and suggest a novel role for curcumin in inducing a beneficial form of autophagy in HUVECs, which may be a potential multitargeted therapeutic avenue for the treatment of oxidative stress-related cardiovascular diseases.

Curcumin induces autophagy to protect vascular endothelial cell survival from oxidative stress damage

Ginsenoside Rg3 attenuates cell migration via inhibition of aquaporin 1 expression in PC-3M prostate cancer cells.

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1016/j.molonc.2012.03.005

Curcumin inhibits tumor proliferation induced by neutrophil elastase through the upregulation of α1-antitrypsin in lung cancer

Background/Aims. Refractory wounds in diabetic patients constitute a serious complication that often leads to amputation with limited treatment regimens. The present study was designed to determine the protective effect of Ganoderma lucidum polysaccharide (Gl-PS) on diabetic wound healing and investigate underlying mechanisms. Methods. Streptozotocin (STZ)-induced type 1 diabetic mice with full-thickness excisional wounds were intragastrically administered with 10, 50 or 250 mg/kg/day of Gl-PS. Results. Gl-PS dose-dependently rescued the delay of wound closure in diabetic mice. 50 and 250 mg/kg/day of Gl-PS treatment significantly increased the mean perfusion rate around the wound in diabetic mice. Diabetic conditions markly increased mitochondrial superoxide anion (O2·-) production, nitrotyrosine formation, and inducible nitric oxide synthase (iNOS) activity in wound tissues, which were normalized with Gl-PS treatment. In diabetic wound tissues, the protein level of manganese superoxide dismutase (MnSOD) was unchanged whereas MnSOD activity was inhibited and its nitration was potentiated; Gl-PS administration suppressed MnSOD nitration and increased MnSOD and glutathione peroxidase (GPx) activities. Moreover, Gl-PS attenuated the redox enzyme p66Shc expression and phosphorylation dose-dependently in diabetic mice skin. Conclusion. Gl-PS rescued the delayed wound healing and improved wound angiogenesis in STZ-induced type 1 diabetic mice, at least in part, by suppression of cutaneous MnSOD nitration, p66Shc and mitochondrial oxidative stress.

/pdf/ganoderma-lucidum-polysaccharide-accelerates-refractory-2npueievp8.pdf

Yan Xu

Papers

Curcumin induces autophagy to protect vascular endothelial cell survival from oxidative stress damage

Ginsenoside Rg3 attenuates cell migration via inhibition of aquaporin 1 expression in PC-3M prostate cancer cells.

Curcumin inhibits tumor proliferation induced by neutrophil elastase through the upregulation of α1-antitrypsin in lung cancer

Ganoderma lucidum polysaccharide accelerates refractory wound healing by inhibition of mitochondrial oxidative stress in type 1 diabetes.

Opposite angiogenic outcome of curcumin against ischemia and Lewis lung cancer models: in silico, in vitro and in vivo studies.