Tumor-derived exosomes (TDEs) participate in formation and progression of different cancer processes, including tumor microenvironment (TME) remodeling, angiogenesis, invasion, metastasis and drug-resistance. Exosomes initiate or suppress various signaling pathways in the recipient cells via transmitting heterogeneous cargoes. In this review we discuss exosome biogenesis, exosome mediated metastasis and chemoresistance. Furthermore, tumor derived exosomes role in tumor microenvironment remodeling, and angiogenesis is reviewed. Also, exosome induction of epithelial mesenchymal transition (EMT) is highlighted. More importantly, we discuss extensively how exosomes regulate drug resistance in several cancers. Thus, understanding exosome biogenesis, their contents and the molecular mechanisms and signaling pathways that are responsible for metastasis and drug-resistance mediated by TDEs may help to devise novel therapeutic approaches for cancer progression particularly to overcome therapy-resistance and preventing metastasis as major factors of cancer mortality.

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Transforming growth factor-β (TGF-β) induces pro-inflammatory cytokines expression including interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) and these cytokines are associated with the development of atherosclerosis. Curcumin has anti-atherogenic effects and anti-inflammatory properties in the vascular wall, but the relative mechanisms are almost unknown. In the present study, we investigate the effect of curcumin on modulating the pro-inflammatory action of TGF-β in human vascular smooth muscle cells (VSMCs) and its molecular mechanisms. Cultured VSMCs were seeded into several groups: a control group (untreated group), a group treated with TGF-β, and several groups treated with TGF-β plus inhibitors. The cells were pre-treated with diphenyleneiodonium chloride, DPI, (20 μM), curcumin (5, 10 and 20 μM) and N-Acetyl-L-Cysteine, NAC, (10 mM) and then TGF-β (5 ng/mL) was added to the culture medium. The mRNA levels of IL-6 and TNF-α were detected by quantitative Real-Time Polymerase Chain Reaction. For monitoring the Smad2 linker region phosphorylation (pSmad2L), the western-blotting technique was applied and reactive oxygen species (ROS) generation was measured by utilizing 2′,7′-dichlorofluorescein diacetate-based assay. TGF-β increased the mRNA expression of IL-6 (p=0.02 and p=0.001) and TNF-α (p =0.014 and p=0.001) in a time-dependent manner, ROS production (p=0.03) and Smad2L phosphorylation (p=0.015). Pre-treatment with curcumin, DPI and NAC inhibited TGF-β–induced IL-6 (p=0.04) and TNF-α (p=0.001) mRNA expression, Smad2L phosphorylation (p=0.02) and ROS production (0.03). Pharmacological inhibition by Curcumin blocks TGF-β–induced ROS production, Smad2L phosphorylation, and IL-6 and TNF-α mRNA expression in human VSMCs.  

Background: Piperine is a natural compound obtained from the Piper nigrum that exhibits anti-proliferative and anti-cancer activity in cancer cell lines. We analyzed the cytotoxic effect of piperine combined with cisplatin compound in the human MCF-7 breast cancer cell line and the underlying mechanism. Methods: The present in vitro study was performed on MCF-7 cell line in Jahrom University of Medical Sciences between, Jahrom, Iran from 2016 to 2017. Cultured MCF-7 cells were seeded into four groups: a control group (untreated group), a group treated with cisplatin, a group treated with piperine and a group treated with cisplatin and piperine. Cell viability was analyzed using the MTT assay method. Flow c-ytometric analysis was investigated for apoptosis. The mRNA and protein expression of the apoptotic regulators p53, Bcl-2, Bax, caspase 3 and caspase 9 were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting analysis. Results: Piperine (20 and 30 µM) in combination with cisplatin (5, 10 and 15 µM) for 24 h synergistically inhibited cell viability of MCF-7 breast cancer cells more than piperine and cisplatin used alone. Synergistic antibreast cancer activities cisplatin (5 µM) and piperine (20 µM) were via inducing apoptosis. Piperine (20 µM) and cisplatin (5 µM) for 24 h induce apoptosis strongly through reduction of Bcl-2 and increase of caspase 3, p53, caspase 9, and Bax. Conclusion: Piperine in combination with cisplatin could trigger p53-mediated apoptosis more effective than cisplatin alone in MCF-7 breast cancer cells, reducing the toxic dose of cisplatin used in cancer chemotherapy.