ABSTRACT
PURPOSE: Tumor necrosis factor (TNF)-related apoptosis inducing ligand (TRAIL)/APO-2L is a member of the TNF family that can kill a wide variety of tumor cells, but not normal cells. This study was designed to investigate the down stream target proteins in TRAIL-mediated apoptosis of human liver, Chang cells. MATERIALS AND METHODS: The expressions of DR4/DR5 in hepatoma cells, including Chang, HepG2 and Hep3B cells, were determined by RT-PCR. Cell viability was measured by MTT assay and apoptosis was assessed by DNA fragmentation assay. The catalytic activity of caspase- family proteases, including caspase-3 and -9, was tested by using fluorogenic biosubstrates. Expression of apoptotic mediators, including procaspase-3 and PARP proteins, was measured by Western blotting. The expression profile of proteins in Chang cells by using two-dimensional (2-D) gel electrophoresis and MALDI-TOF. RESULTS: The results demonstrated that TRAIL (100 ng/ml) induced the apoptotic death of Chang cells, as characterized by the ladder-pattern fragmentation of genomic DNA. TRAIL increased the enzymatic activity of caspase- 3, corresponding to the time of appearance of cleaved PARP and caspase-9. In 2-D gel electrophoresis and MALDI- TOF analysis, the comparison of control versus apoptotic cells in the protein expressions revealed that signal intensity of 7 spots were decreased, whereas 6 spots were increased among 300 spots. These spots were resolved and identified as a protein information by MALDI-TOF. CONCLUSION: We suggested that TRAIL induces the apoptotic death of Chang cells via proteome alterations inducing caspase cascade.
Subject(s)
Humans , Apoptosis , Blotting, Western , Carcinoma, Hepatocellular , Caspase 3 , Caspase 9 , Cell Survival , DNA , DNA Fragmentation , Electrophoresis , Electrophoresis, Gel, Two-Dimensional , Liver , Peptide Hydrolases , Proteome , Rivers , Tumor Necrosis Factor-alphaABSTRACT
Objective To understand the effect of Schistosoma japonicum infection on Oncomelania hupensis. Methods Uninfected Oncomelania snails were collected from the marshland of the Yangtze River in Anhui Province and exposed to and infected with miracidia of S.japonicum in the laboratory. After the exposure, those snails and unexposed snails as the control were raised in the natural environment of the same field and all the snails were observed and recorded every 10 days. The survival rate and death rate were calculated, and expected survival time was also calculated with the animal life table method. Results The peak of death of the infected snails was between 60 and 70 days after the exposure, and the expected survival time was 63.46 days and the longest survival time was 135 days. The peak of death of the unexposed snails was between 80 and 90 days, and the expected survival time was 83.54 days and the longest survival time was 155 days. The expected survival time of the infected snails was 24.04% shorter compared with that of the uninfected. Conclusion The death rate of snails infected with S.japonicum increases and the survival time decreases in the natural environment.
ABSTRACT
0.05). There were significant differences among 3- or 6- or 9- or 12-hour groups and 24- or 36-hour groups in 6, 13 ℃ and 28 ℃ respectively (P