Sencitivity enhancement of U251 cells to TRAIL by cisplatin / 国际肿瘤学杂志

ABSTRACT

Objective To evaluate the positive effects of cisplatin on sensitivity of human glioma U251 to tumor necrosis factor-related apoptosis inducing ligand and to investigate the potential mechanism. Methods The expression of green fluorescent protein (GFP) in U251 which was transfected with pAdxsi-GFP-TRAIL was observed by inverted fluorescent microscope ×400) and to ascertain the MOI. The proliferation inhibition was studied by MTT method. Morphological change was detected through inverted florescent microscope and the Hoechst33342 staining assay was used to verify whether cell apoptosis could be induced or not. The cell apoptosis was also analyzed by flow cvtometry with propidium iodide staining. Semi-quantitative RT-PCR was introduced to detect the mRNA expression of apoptosis related gene.Results The expression of TRAIL mRN A was significantly upregulated after transfection. Compared with treatment group of cisplatin and TRAIL alone, the proliferation of U2S1 was significantly inhibited in the cisplatin sensitizing TRAIL group (P < 0.05 ). Nuclear shrinkage and pyknosis fragmentation were observed by Hoechst 33342 staining assay; Apoptotic peak was detected from the results of flow cvtometry and there were significant differences between the sensitizing group and the other two groups ( P < 0.05 ) ; Moreover, the relatively high expression of TRAIL, DR5, caspaseS and down - regulated survivin genes were also observed. There was no significant changes in DR4 expression. Conclusion Cisplatin could extremely enhance the sensitivity of U251 cells to TRAIL And the potential mechanism may related to the increase of TRAIL, DRS, caspaseS genes while the reduction of surivivin gene.