Inhibitive Effects Of Eukaryotic Vector Of Encoding Recombinant Caspase-3 Gene On Human Gliomas

Objective Glioma is a most common malignancy in nerves system ,and effect of general treats and prognosis are not good .Some studies showed that suppression or unbalance of apoptosis of tumor cells are significantly related with production and growth of glioma;Caspase-3 could induce apoptosis of tumor cells, suppress growth of them and enhance sensitivity of them to chemotherapy and actinotherapy. The aim of this study is to observe apoptosis and inhibited growth of SHG44 human glioma produced by Re-caspase-3.Methods 18 nude mices were randomly divided into therapy group(A), empty vector group(B) and control group(C) equally. According to the groups, the vector of pcDNA-rcaspase-3 packaged by lipofectamine ,empty vector and saline were injected into SHG44 human glioma at subcutaneous tissue of nude mice respectively . The expression of Re-caspase-3 in glioma cells were identified by RT-PCR.The growth of glioma was observed and the reduction in tumor size was calcaulated . The effect of Re-caspase-3 on SHG44 human glioma was recognized according to light microscopy ,electron microscope and dead of tumor cells.Results When SHG44 cells were implanted into subcutis of nude mice ,the formation rate of tumor was 100% for every group. Growth speed of tumor was no significant between each group(P>0.05).21 days after injection ,growth speed in group B and C were quicker than group A ,the difference was significant(P<0.05),but no difference between group B and C(P>0.05) . 40 days after injection , a reduction in tumor size of 46.1% was observed in the mice treated with pcDNA-rcaspase-3. The tumor mass of group A decreased remarkably compared with group B and C respectively.(P<0.05),meanwhile,there was no significant difference between group B and C (P>0.05). In the light microscopy, loose distributions and dead of tumor cell were observed in the group A, meanwhile uniform distributions , tight arrangement and nest arrangement of tumor cells at some regions in the control group. A gene segment was got by RT-PCR from tumor cell of group A, which was 894bp gene of Re-caspase-3 identified by electrophoresis, There were not the gene in group B and C.In the transmission electron microscopy ,chromatin aggregation or migration to the margin and shrinkage of the nucleus were observed in group A, but no these findings in the control group.Conclusion Our results showed that:⑴. nude DNA of Rev-caspase-3 could be expressed in the SHG44 human glioma ;⑵. nude DNA of Rev-caspase-3 could promote apoptosis and dead of human glioma cells, and suppress growth of them.⑶These findings provide a basis for the further development of gene therapy of glioma.