The malignant traits involved in tumor relapse, metastasis and the expansion of cancer stem-like cells are acquired via the epithelial-mesenchymal transition (EMT) process in the tumor microenvironment. In addition, the tumor microenvironment strongly supports the survival and growth of malignant tumor cells and further contributes to the reduced efficacy of anticancer therapy. Ionizing radiation can influence the tumor microenvironment, because it alters the biological functions of endothelial cells composing tumor vascular systems.
View Article and Find Full Text PDFIn this research, we firstly demonstrated that physcion, an anthraquinone derivative, specifically increased the expression of the human α2,8-sialyltransferase (hST8Sia VI) gene in SK-N-BE(2)-C human neuroblastoma cells. To establish the mechanism responsible for the up-regulation of hST8Sia VI gene expression in physcion-treated SK-N-BE(2)-C cells, the putative promoter region of the hST8Sia VI gene was functionally characterized. Promoter analysis with serially truncated fragments of the 5'-flanking region showed that the region between -320 and -240 is crucial for physcion-induced transcription of hST8Sia VI in SK-N-BE(2)-C cells.
View Article and Find Full Text PDFSerum deprivation (SD) is well known to induce G0/G1 cell cycle arrest and apoptosis in various cells. In the present study, we firstly found that SD could induce G1 arrest and the differentiation of human osteoblastic MG-63 cells, as evidenced by the increase of osteoblastic differentiation markers, such as bone morphogenetic protein-2 (BMP-2), osteocalcin and runt-related transcription factor 2 (Runx2). In parallel, gene expression of human GM3 synthase (hST3Gal V) catalyzing ganglioside GM3 biosynthesis was upregulated by SD in MG-63 cells.
View Article and Find Full Text PDFWe first demonstrated that cordycepin inhibited cell growth and triggered apoptosis in U87MG cells with wild-type p53, but not in T98G cells with mutant-type p53. Western blot data revealed that the levels of procaspase-8, -3, and Bcl-2 were downregulated in cordycepintreated U87MG cells, whereas the levels of Fas, FasL, Bak, cleaved caspase-3, -8, and cleaved PARP were upregulated, indicating that cordycepin induces apoptosis by activating the death receptor-mediated pathway in U87MG cells. Cordycepin-induced apoptosis could be suppressed by only SB203580, a p38 MAPK-specific inhibitor.
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