Objective In this research ,the effects of exogenous C 2-ceramide on the induction of apop-tosis of mesothelioma cells in vitro and related important proteins are investigated .Mtehods Mesothelioma cells were treated with various doses of C 2-ceramide for different duration .Cell viability were analyzed by cell count-ing kit-8 assay.Morphological changes of apoptosis of mesothelioma cells were observed by Diff Quik staining . Apoptosis of mesothelioma cells was also detected by Caspase -3 assay and lactate dehydrogenase(LDH)assay. Related important proteins involved in the signal transduction of apoptosis were detected by western blot .Results In vitro,C2-ceramide demonstrated a dose -and time-dependent inhibition of cell proliferation .Apoptotic bodies were observed by Diff Quik staining .The antiproliferative effect of 80 μm C2-ceramide was paralleled with an increase in Caspase -3 activity.LDH assay showed that C2-ceramide at a concentration of 80μm signifi-cantly promoted cells death .After treated by C2-ceramide,the expressions of Bax and the phosphorylated JNK in mesothelioma cells were increased , however , the expression of phosphorylated ERK 1/2 kinase was decreased . Conclusion Our results indicate that C 2-ceramide induced apoptosis of malignant mesothelioma cells in vitro . This anti-tumor affect is achieved by adjusting related important proteins .

In this paper we established a method of preparing chromosomes of peritoneal cells and made use of the method for observing the Y-chromosome of marrow and peritoneal cells of female mice which had been irradiated with 850 rad ~(60)Co-?, rays and then transplanted with marrow cells of male mice. The results showed that the chromosome karyotypes of the marrow cells of the female mice were of the XY type of male mice. It means that the marrow cells of the recipients were substituted by those of the donors. At the same time, the chromosome types of the peritoneal cells of the recipients were also of the XY type. It is suggested that the peritoneal cells were derived from the marrow cells.By the use of the method for assaying CFU-C and CFU-S of mouse marrow cells, CFU-C and CFU-S of peritoneal cells of mice were assayed. The result demonstrated that there were a number of CFU-C and CFU-S among the peritoneal cells.On the observation of the cell morphology of CFU-C and CFU-S, it was discovered that CFU-C differentiated mainly into mononuclear phagocytes, while CFUS had the ability to differentiate into erythrocytie series and granulocytic series, which implies that there were some multipotential stem ceils among peritoneal cells of mice.When more than 10~6 peritoneal cells per mouse were transplanted into the mice which had received 850 rad of ~(60)Co-? rays, their life span could be prolonged.It is still a question unsetteled that whether the stem cells in the peritoneal cavity differentiate diroctly into the mononuclear phagocytes or the mononuclear cells in the blood penetrate into the peritoneal cavity and then differentiate into the macrophages.