Rhabdomyosarcoma (RMS) is a predominant soft tissue tumor in children and adolescents. For high-grade RMS with metastatic involvement, the 3-year overall survival rate is only 25 to 30%. Thus, understanding the regulatory mechanisms involved in promoting the metastasis of RMS is important. Here, we demonstrate for the first time that the SNAIL transcription factor regulates the metastatic behavior of RMS both in vitro and in vivo. SNAIL upregulates the protein expression of EZRIN and AKT, known to promote metastatic behavior, by direct interaction with their promoters. Our data suggest that SNAIL promotes RMS cell motility, invasion and chemotaxis towards the prometastatic factors: HGF and SDF-1 by regulating RHO, AKT and GSK3b activity. In addition, miRNA transcriptome analysis revealed that SNAIL-miRNA axis regulates processes associated with actin cytoskeleton reorganization. Our data show a novel role of SNAIL in regulating RMS cell metastasis that may also be important in other mesenchymal tumor types and clearly suggests SNAIL as a promising new target for future RMS therapies.

During the progression of epithelial cancer, the cells may lose epithelial markers and gain mesenchymal phenotype via Epithelial-Mesenchymal Transition (EMT). Such transformation of epithelial cancer cells to mesenchymal-like characteristic benefits plasticity and supports their ability to migrate. The aim of this study was to evaluate the influence of natural compound Caffeic Acid (CA) alone and in combination with antidiabetic drug Metformin (Met) on metastatic progression of two human cervical squamous cell cancer lines, C-4I and HTB-35/SiHa cells. EMT program was triggered by exposition of both epithelial cell lines to TGF-β1. Gene expression patterns related to epithelial/mesenchymal phenotype were evaluated by Real-Time PCR analysis and the protein amount was detected by western blot. The treatment of human squamous cancer cells with CA and with Met, suppressed the motility of cells and the effect depended on a particular cell line. Both compounds regulated the EMT process in C4-I and HTB-35 cells by interfering with different molecular targets. In TGF-β1-stimulated C4-I cells, CA suppressed the expression of mesenchymal transcription factor SNAI1 which resulted in enhanced expression of epithelial markers E-cadherin, Occludin and Claudin. Additionally, CA blocked MMP-9 and upregulated TIMP-1 expression, a specific inhibitor of MMP-9. In HTB-35 cells stimulated with TGF-β1, Met decreased the expression of Vimentin. By suppressing hypoxia master regulator HIF-1α, Met caused downregulation of CAIX, an enzyme involved in metastasis of aggressive malignant cells. In this study we showed that CA and Met inhibited EMT process in cancer cells via different mechanisms. However, when applied together, compounds exerted the greater effect on EMT than each compound alone. This is the first report revealing that CA alone and co-treated with Met may reverse mesenchymal phenotype of TGF-β1-treated cervical tumor cells and we believe that the use of the two small molecules may be considered as a potential therapeutic approach for metastatic cervical cancer.

The crucial role of microtubules in the mitotic-related segregation of chromosomes makes them an excellent target for anticancer microtubule targeting drugs (MTDs) such as, e.g., vinflunine (VFL), colchicine (COL), and...

Rhabdomyosarcoma (RMS) is a soft tissue mesenchymal tumor that affects mostly children and adolescents. It originates from the impaired myogenic differentiation of stem cells or early progenitors. SNAIL, a transcription factor that regulates epithelial-to-mesenchymal transition in tumors of epithelial origin, is also a key regulator of RMS growth, progression, and myogenic differentiation. Here, we demonstrate that the SNAIL-dependent microRNAs (miRNAs) miR-28-3p and miR-193a-5p are crucial regulators of RMS growth, differentiation, and progression. miR-28-3p and miR-193a-5p diminished proliferation and arrested RMS cells in G0/G1 phase in vitro . They induced the myogenic differentiation of both RMS cells and human myoblasts by upregulating myogenic factors. Furthermore, miR-28-3p and miR-193a-5p inhibited migration in a scratch assay, adhesion to endothelial cells, chemotaxis, and invasion toward SDF-1 and HGF and regulated angiogenic capabilities of the cells. Overexpression of miR-28-3p and miR-193a-5p induced formation of fibrotic structures and abnormal blood vessels in RMS xenografts in immunodeficient mice in vivo . Simultaneous overexpression of both miRNAs diminished tumor growth after subcutaneous implantation and inhibited the engraftment of RMS cells into bone marrow after intravenous injection in vivo . To conclude, we discovered novel SNAIL-dependent miRNAs that may become new therapeutic targets in RMS in the future.

The S-Allyl-L-cysteine (SAC) component of aged garlic extract (AGE) is proven to have anticancer, antihepatotoxic, neuroprotective and neurotrophic properties. γ-Cystathionase (CTH), cystathionine β-synthase (CBS) and 3-mercaptopyruvate sulfurtransferase (MPST) are involved in H2S/sulfane sulfur endogenous formation from L-cysteine. The aim of the study was to determine the effect of SAC on MCF-7 cells survival and apoptosis, which is a widely known approach to reduce the number of cancer cells. An additional goal of this paper was to investigate the effect of SAC on the activity and expression of enzymes involved in H2S production. The experiments were carried out in the human breast adenocarcinoma cell line MCF-7. Changes in the cell viability were determined by MTT assay. Cell survival was determined by flow cytometry (FC). Changes in enzymes expression were analyzed using Western blot. After 24 h and 48 h incubation with 2245 µM SAC, induction of late apoptosis was observed. A decrease in cell viability was observed with increasing SAC concentration and incubation time. SAC had no significant cytotoxic effect on the MCF-7 cells upon all analyzed concentrations. CTH, MPST and CBS expression were confirmed in non-treated MCF-7 cells. Significant decrease in MPST activity at 2245 µM SAC after 24 h and 48 h incubation vs. 1000 µM SAC was associated with decrease in sulfane sulfur levels. The presented results show promising SAC effects regarding the deterioration of the MCF-7 cells’ condition in reducing their viability through the downregulation of MPST expression and sulfate sulfur level reduction.