BACKGROUND:Human mesenchymal stem cells derived from Wharton's jelly(WJCs)display the characteristics of MSCs as defined by the International Society for Cellular Therapy.They can be differentiated into bone,cartilage,adipose,muscle,and neural cells.They can also support the expansion of other stem cells,be weli-tolerated by the immune system,and have the ability to home to tumors.OBJECTIVE:To investigate biological changes of WJCs and brain tumor stem cells(BTSCs)co-cultured in vitro.METHODS:WJCs cultured by situ cultivation and BTSCs used enzyme digestion way respectively,and gathering the 3rd passage of WJCs though subculturing as well as BTSCs.Two kinds of cells co-cultured in 24-well plates in serum-free medium (SFM)without any growth factor.3 and 7 days after co-cultured respectively,CD133 expression of suspension cells in the 24-well plates were identified by flow cytometry,and immunofluorescence was performed for Nestin and glial fibrillary acidic protein (GFAP)expression of adherent cells.Co-culture supernatant(CCS)re-suspended 3~(rd) passage of BTSCs and cultured into 96-well plates at day 3,which were used to determine the difference in cell growth curve in both groups using a microplate reader.RESULTS AND CONCLUSION:With the cocultivation days increasing,the phenomenon that tumor sphere cells began to be decomposed,adherent and differentiated observed by an inverted microscope.BTSCs in the co-cultured group expressed GFAP and Nestin when adherent and differentiated.The higher degree of malignant brain tumor tissue used in culturing BTSCs was,the higher expression of CD133 in BTSCs was.CD 133~+ in BTSCs declined when co-cultured with WJCs.Growth curve of brain tumor stem cells cultured in CCS compared with in SFM at day 3,which indicates that the proliferation of BTSCs inhibited obviously.Results indicated that CD 133~+ expression and proliferative capacity of BTSCs went down and BTSCs underwent differentiation during the co-culture in vitro.

Objective:To investigate the effect and mechanism of miR-377-5p on the radiosensitivity of esophageal cancer cell line TE-1.Methods:Esophageal cancer cell line TE-1 was transfected with miR-377-5p mimic and miR-377-5p mimic NC to construct the TE-1 cells overexpressing miR-377-5p. After the transfected TE-1 cells were exposed to ionizing radiation, radiobiological parameters(D 0, D q, SF 2) were detected by plate colony formation assay. Cell invasion ability was assessed by Transwell chamber assay, Cell migration ability was evaluated by cell scratch assay, Cell viability was assessed by CCK8 assay. Cell apoptosis and cell cycle were detected by flow cytometry, Western blot. The phosphorylation levels of AKT1 and GSK-3βwere measured by Western blot. Results:At the doses of 2, 4, 6, and 8 Gy, the colony formation rate in each group was significantly decreased (all P<0.05), and the colony formation rate at the same irradiation dose in the miR-377-5p mimic group was significantly lower than that in the miR-377-5p mimic NC group ( P<0.05). Compared with the miR-377-5pmimic NC group, the D 0, D q and SF 2 at 2 Gy were decreased significantly in the miR-377-5pmimic group (all P<0.05), and the radiosensitization ratio(D 0 ratio) was 1.34. After 0 Gy ionizing radiation, the invasion, migration and proliferation abilities of TE-1 cells were significantly decreased, the level of cell apoptosis was significantly increased, the cell cycle was arrested in G 1 phase, and the phosphorylation levels of AKT1 and GSK-3β were significantly decreased in the miR-377-5pmimic group (all P<0.05). Following 4 Gy irradiation, cell invasion, migration, proliferation abilities were decreased, the level of cell apoptosis was increased significantly, the G 1 phase was significantly extended and the phosphorylation levels of AKT1 and GSK-3β were also decreased significantly in the miR-377-5pmimic group (all P<0.001). Conclusion:miR-377-5p can increase the radiosensitivity of esophageal cancer cell line TE-1, which may be due to the inhibition of the AKT1/GSK-3β signaling pathway.