Prokaryotic microvesicles Ortholog of eukaryotic extracellular vesicles in biomedical fields.

Every single cell can communicate with other cells in a paracrine manner via the production of nano-sized extracellular vesicles. This phenomenon is conserved between prokaryotic and eukaryotic cells. In eukaryotic cells, exosomes (Exos) are the main inter-cellular bioshuttles with the potential to carry different signaling molecules. Likewise, bacteria can produce and release Exo-like particles, namely microvesicles (MVs) into the extracellular matrix. Bacterial MVs function with diverse biological properties and are at the center of attention due to their inherent therapeutic properties. Here, in this review article, the comparable biological properties between the eukaryotic Exos and bacterial MVs were highlighted in terms of biomedical application. Video Abstract.

Suppressing effects of green tea extract and Epigallocatechin-3-gallate (EGCG) on TGF-ß- induced Epithelial-to-mesenchymal transition via ROS/Smad signaling in human cervical cancer cells.

BACKGROUND: Transforming growth factor-ß (TGF-ß)-induced Epithelial-to-mesenchymal transition (EMT) process is a fundamental target for preventing cervical cancer cells' progression and invasion. Green tea and its principal active substance, Epigallocatechin-3-gallate (EGCG), demonstrate anti-tumor activities in various tumor cells. METHODS: The cell viability of two cervical cancer cell lines, Hela and SiHa, in the experimental groups was examined employing the MTT method, and ROS generation was probed applying 2',7'-dichlorofluorescein diacetate-based assay. The Smad signaling and EMT process was evaluated utilizing western blot analysis and quantitative real-time polymerase chain reaction (qRT-PCR). Chromatin immunoprecipitation (ChIP) and Smad binding element (SBE)-luciferase assays were employed to measure Smad-DNA interaction and Smad transcriptional activity, respectively. RESULTS: EGCG (0-100 µmol/L) and green tea extract (0-250 µg/ml) suppressed the viability of cancer cells in a dose-dependent manner (p < 0.01). Our conclusions affirmed that pre-incubation with green tea extract (80 µg/ml) and EGCG (60 µmol/L) significantly reversed the impacts of TGF-ß in Hela and SiHa cells by decreasing Vimentin, ZEB, Slug, Snail, and Twist and increasing E-cadherin expression. The molecular mechanism of green tea extract and EGCG for TGF-ß-induced EMT inhibition interfered with ROS generation and Smad signaling. Green tea extract and EGCG could significantly decrease ROS levels, the phosphorylation of Smad2/3, the translocation, DNA binding, and activity of Smads in cervical cancer cell lines treated with TGF-ß1 (p < 0.01). CONCLUSION: EGCG and green tea extract suppressed TGF-ß-induced EMT in Hela and SiHa cells, and the underlying molecular mechanism may be related to the ROS generation and Smad signaling pathway.

Synergistic effects of green tea extract and paclitaxel in the induction of mitochondrial apoptosis in ovarian cancer cell lines.

BACKGROUND: Green tea is a natural compound with anti-neoplastic properties. Paclitaxel (PTX) is a natural anti-tumor medication used to manage patients with advanced ovarian cancer. This manuscript evaluated the cytotoxic effects of green tea extract combined with PTX drug in two human ovarian cancer cell lines (p53-negative cell line, SKOV-3; and mutant type p53 cell line, OVCAR-3) and underlying mechanisms. METHODS: The human ovarian cancer cell lines were treated with green tea extract, PTX, and green tea plus PTX for 24 h, and cell viability was assessed using the MTT method. Flow cytometric analyses were carried out to detect apoptosis. For the apoptotic process, quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting analysis were applied to study pAkt, Bax, Bcl-2, Cytochrome C (Cyt-C), cleaved-caspase-3, and cleaved-caspase-9 levels after drug treatments. RESULTS: Our results pointed out that various green tea (25 and 50 µg/ml) concentrations combined with PTX (20 and 40 µg/ml) synergistically inhibited cell viability of cancer cells more than green tea or PTX alone after 24 h of treatment. Also, green tea and PTX combination induced apoptosis in ovarian cancer cells by blocking the phosphorylation of Akt and the expression of Bcl-2 while inducing Bax, Cyt-C, cleaved-caspase 3, and cleaved-caspase 9. CONCLUSION: Our results showed that the combination of green tea and PTX could be more potent than the individual drug to induce cytotoxicity and apoptosis in ovarian cancer cells.

In Vitro Effects of Curcumin on Transforming Growth Factor-ß-mediated Non-Smad Signaling Pathway, Oxidative Stress, and Pro-inflammatory Cytokines Production with Human Vascular Smooth Muscle Cells.

Transforming growth factor-ß (TGF-ß) 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-ß 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-ß, and several groups treated with TGF-ß 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-ß (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-ß 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-ß-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-ß-induced ROS production, Smad2L phosphorylation, and IL-6 and TNF-α mRNA expression in human VSMCs.