英语翻译Objective To observe the in vitro growth inhibitory and

英语翻译Objective To observe the in vitro growth inhibitory and apopto sis-inducing effects of paclitaxel on the human osteosarcoma cell line U2- OS.Methods U-2 OS cells were treated with various concentrations of paclitaxel.Proliferation was determined by cell count in a neubauer cytometer chamber1.Viability was assessed by trypan blue dye exclusion.Paclitaxel-induced morphologic alterations were visualized using light and transmission electron microscopy.The extent of paclitaxel-induced apoptosis was determined by flow cytometry and immunohistochemicaldetection (TdT2-ediated dUTP nickend labeling technique ,TUNEL) .Results The cells treated with paclitaxel initially showed G2/ M arrest ,which was followed by apoptosis.The characteristic apoptotic changes ,including nuclear disintegration and chromatin agglomeration ,weredisplayed.Large amounts of micronuclei cells appeared ,something not observed in those cells treated withcisplatin and adriamycin for contrast.Also ,extensive DNA-cleavage was detected using TUNEL.Conclusion This study demonstrates that paclitaxel has an apoptotic-inducing effect on osteo sarcoma cells through the initiation of G2/ M arrest and inhibiting mitosis in both a time-dependent and dose-dependent manner.