| The hepatocarcinoma has an important position in the incidence and mortality of human malignant tumors. Many studies have shown that chemical factors are related closely to hepatocarcinogenesis, but the mechanism is not clear. Some researches indicated that reactive oxygen species (ROS) might be involved in hepatocarcinogenesis, but there is no definitive evidence at present especially in cellular and molecular level in vitro.The liver oval cell line WB-F344 derives from adult normal Fisher 344 male rats. It's a kind of liver infantine epithelial cells and has characteristics of liver stem cells. Many studies in vitro and in vivo imply that it has the role as precursor cells of hepatocacinoma, which indicates its function in hepatocarcinogenesis. Tsao et al have observed that MNNG acted several times could induce WB cells transformation, but the study of inducing its malignant transformation directly by ROS has not been reported. ROS mainly include O2·-, H2O2 and ·OH, which have relationship with many kinds of human diseases including cancer. O2·- is the mainly source of body's ROS generated by enzyme and nonenzyme system reactions of mitochondria microsome cell membrane and cytoplasm. All aerobic organisms can produce O2·-, which can become H2O2 by disproportionation reaction and more reactive ·OH by Fenton reaction. O2·- is relative difficult to be studied because of its short life. Our lab has observed the transformation effect of O2·- on NIH3T3 cells, which approved primarily its effect of carcinogenesis especially in promoting. The objective of this paper is to study the effect of promoting malignant transformation of O2·- on WB-F344 cells based on the former work and firstly to study the molecular mechanism of the cells transformation from the aspects of the dynamic change of related oncogene expression during transformation, the content of important intracellular signal...
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