Research On The Effect Of RNA Interference Silencing DcR3 Gene To Human Colon Carcinoma Implant Tumor In Athymic Mice

[Objective]DcR3 siRNA suppresses colon carcinoma cells proliferation and induce them apoptosis by specific silencing the expression of DcR3 mRNA gene in colon carcinoma SW480 cells. According to this, by abserving the expression of DcR3 in athymic micetransplantation tumor treated subcutaneouly by human colon carcinoma SW480 cells and analyzing the effect of DcR3 siRNA to investigate the effect of DcR3 siRNA to the growth of transplantation tumor and possible mechanism of action.[Methods]1. Athymic mice were subcutaneously transplanted with human colon carcinoma SW480 cells to establish transplanted tumor model.2. To aim directly at target gene—DcR3, siRNA sequence was synthesized by Dharmacon company software , then transfected into subcut transplantation tumor in athymic mice. To establish negative and blank control group.3. The suppression effect of DcR3 siRNA to tumor was estimated and the change of morphocytology was compared by observing the tumor volume change on pretherapy and posttherapy. The genetic expression of DcR3 was detected by immunohistochemistry and reverse transcriptase polymerase chain reaction, the tumor apoptosis was detected by TUMEL method.[Results]1. The implanted tumor model with human colon carcinoma SW480 cells in athymic mice was susussfully established.2. By the application of reverse transcriptase polymerase chain reaction, it proved that the expression of DcR3 gene were distinct in each group on posttherapy . The relative optical density was obviously lower in treatment group than in negative and blank control group. (P<0.05).3. The result of immunohistochemistry displayed that the intracytoplasm color was lighter in treatment group than in negative and blank control group by.it exists significant deviation(P<0. 01).4. The transplantation tumor volume was significantly smaller in treatment group than in contol groups.5. It was detected that the tumor cells apoptosis number was much more in treatment group than in control groups by TUNEL method (P<0.01) .[Conclusions]1. Human colon carcinoma SW480 cells have satisfactory characteristic with tumorigenesis. 2. DcR3 gene can create specific expression in subcut transplantation tumor of athymic mice.3. DcR3 siRNA Mediated by liposome distinctly inhibits and kills subcut transplantation tumor with human colon carcinoma SW480 cells in athymic mice.