Objective: Irradiation may enhance migration and/or invasiveness of cancer cells in vitro and in vivo, the mechanism of which may be associated with epithelial-mesenchymal transition (EMT). The present study explored ...Objective: Irradiation may enhance migration and/or invasiveness of cancer cells in vitro and in vivo, the mechanism of which may be associated with epithelial-mesenchymal transition (EMT). The present study explored the mechanisms of EMT induced by irradiation in esophageal cancer cells. Methods: Human esophageal cancer cell line EC109 was treated with increased doses of irradiation (0 Gy, 20 Gy, 40 Gy and 60 Gy). Cell morphology was observed. Expressions of E-cadherin and vimentin were determined by immunofluorescence assay or western blot. Secretion of transforming growth factor-β1 (TGF-β1) by cells was determined by enzyme-linked immunosorbent assay (ELISA), and the expressions of Smad2/3 and phosphorated Smad2 (p-Smad2) were also examined by Western blot. The mRNA expressions of BMP-4, a bone morphogenetic protein (BMP) ligand, and two secreted BMP antagonists (Chordin and Gremlin), were detected with reverse transcription-polymerase chain reaction (RT-PCR). Cell migratory capacity was evaluated. Results: Irradiation induced EMT in EC109 cells in a dose-dependent manner as evidenced by morphological changes, decreased expression of E-cadherin and increased expression of vimentin, and increased cell motility. The secretion of TGF-β1 and expression of p-Smad2 were gradually increased in an irradiation dose-dependent manner, but the Smad2/3 protein levels remained stable. The mRNA expression of BMP-4 was gradually down-regulated, but the expressions of Chordin and Gremlin were gradually up-regulated in cells treated with increased doses of irradiation. Conclusion: Irradiation can induce EMT in esophageal cancer cells in a dose-dependent manner, and the mechanism may be associated with activation of TGF-β and restriction of BMP signaling.展开更多
The method of plasma-spray coating of hy- droxyapatite （HA） onto pure titanium has been demon- strated to be effective to enhance the osteogenic differentiation and accelerate bone regeneration. Yet it is still a bi...The method of plasma-spray coating of hy- droxyapatite （HA） onto pure titanium has been demon- strated to be effective to enhance the osteogenic differentiation and accelerate bone regeneration. Yet it is still a big challenge to figure out the interplay among im- plant surface properties, adsorbed proteins and cell-surface interactions. In this study, the plasma-sprayed HA-coated titanium （HA-Ti） surface was compared with the titanium substrate in terms of protein adsorption, cell adhesion and differentiation. The phase composition, wettability and to- pography were characterized. Compared to the Ti substrate, the HA-Ti had a smaller water contact angle, but larger micro-scale roughness, and showed a poorer ability to ad- sorb fibronectin （Fn）, bovine serum albumin （BSA） and serum proteins. However, it could adsorb larger amount of recombinant human bone morphogenetic protein 2 （BMP- 2）. The osteoblasts and bone marrow mesenchymal stem cells （BMSCs） tended to adhere on the Ti substrate. By contrast, the BMSCs cultured on the HA-Ti showed a stronger tendency toward osteogenesis differentiation.展开更多
基金supported by a grant from the Huai'an City Science and Technology Support Program (Social Development) (No. HAS 2010010)
文摘Objective: Irradiation may enhance migration and/or invasiveness of cancer cells in vitro and in vivo, the mechanism of which may be associated with epithelial-mesenchymal transition (EMT). The present study explored the mechanisms of EMT induced by irradiation in esophageal cancer cells. Methods: Human esophageal cancer cell line EC109 was treated with increased doses of irradiation (0 Gy, 20 Gy, 40 Gy and 60 Gy). Cell morphology was observed. Expressions of E-cadherin and vimentin were determined by immunofluorescence assay or western blot. Secretion of transforming growth factor-β1 (TGF-β1) by cells was determined by enzyme-linked immunosorbent assay (ELISA), and the expressions of Smad2/3 and phosphorated Smad2 (p-Smad2) were also examined by Western blot. The mRNA expressions of BMP-4, a bone morphogenetic protein (BMP) ligand, and two secreted BMP antagonists (Chordin and Gremlin), were detected with reverse transcription-polymerase chain reaction (RT-PCR). Cell migratory capacity was evaluated. Results: Irradiation induced EMT in EC109 cells in a dose-dependent manner as evidenced by morphological changes, decreased expression of E-cadherin and increased expression of vimentin, and increased cell motility. The secretion of TGF-β1 and expression of p-Smad2 were gradually increased in an irradiation dose-dependent manner, but the Smad2/3 protein levels remained stable. The mRNA expression of BMP-4 was gradually down-regulated, but the expressions of Chordin and Gremlin were gradually up-regulated in cells treated with increased doses of irradiation. Conclusion: Irradiation can induce EMT in esophageal cancer cells in a dose-dependent manner, and the mechanism may be associated with activation of TGF-β and restriction of BMP signaling.
基金supported by the National Basic Research Program of China(2011CB606203)the National Natural Science Foundation of China(21434006,21374097)
文摘The method of plasma-spray coating of hy- droxyapatite （HA） onto pure titanium has been demon- strated to be effective to enhance the osteogenic differentiation and accelerate bone regeneration. Yet it is still a big challenge to figure out the interplay among im- plant surface properties, adsorbed proteins and cell-surface interactions. In this study, the plasma-sprayed HA-coated titanium （HA-Ti） surface was compared with the titanium substrate in terms of protein adsorption, cell adhesion and differentiation. The phase composition, wettability and to- pography were characterized. Compared to the Ti substrate, the HA-Ti had a smaller water contact angle, but larger micro-scale roughness, and showed a poorer ability to ad- sorb fibronectin （Fn）, bovine serum albumin （BSA） and serum proteins. However, it could adsorb larger amount of recombinant human bone morphogenetic protein 2 （BMP- 2）. The osteoblasts and bone marrow mesenchymal stem cells （BMSCs） tended to adhere on the Ti substrate. By contrast, the BMSCs cultured on the HA-Ti showed a stronger tendency toward osteogenesis differentiation.
