A study on the apoptosis of hepatoma cells synergistically induced by plasmid-mediated anti-angiogenesis and immunopotentiation therapy / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To study the effect and mechanism of apoptosis of implanted hepatoma cells in mice induced by eukaryotic plasmid-mediated anti-angiogenesis and immunopotentiation therapy.</p><p><b>METHODS</b>Mouse endostatin eukaryotic plasmid (pSecES) and mouse IL-12 (interleukin 12) eukaryotic plasmid (pmIL-12) were extracted and purified from E.coli. H22 hepatoma cells were inoculated into the leg muscles of 32 mice. The mice were divided into four groups with pSecES, pmIL-12, pSecES+pmIL-12 and pcDNA3.1 naked plasmid DNA injected into the tumor cell implantation sites of each group. Tumor formation and their weights were evaluated. Microvessel density, numbers of the infiltrating lymphocytes in the tumors and the apoptosis of tumor cells were assayed by microscopical examination of the CD31 and HE stained slides of the tumors and TUNEL assay.</p><p><b>RESULTS</b>The tumors of those with pSecES or pmIL-12 injections grew slower and with less microvessel density, more lymphocyte infiltration and with more apoptosis tumor cells compared with those with pcDNA3.1 injections. There was much more tumor cell apoptosis in the pSecES+pmIL-12 group (19.9+/-5.5 per 400x microscope field, P less than 0.05) than that in any other single plasmid injection group (400x microscopic field: pSecES 11.3+/-4.1, pmIL-12 14.6+/-3.2, pcDNA3.1 1.4+/-1.3).</p><p><b>CONCLUSIONS</b>Tumor cell apoptosis of the implanted hepatoma in mice can be induced by eukaryotic plasmid-mediated anti-angiogenesis and immunotherapy through inhibiting tumor angiogenesis and promoting tumor lymphocyte infiltration, by which the growth of the implanted hepatoma was inhibited.</p>

Hammerhead ribozyme-mediated cleavage of transforming growth factor beta1 RNA in a cell-free system and in hepatic stellate cells / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To identify the activity of hammerhead ribozyme against transforming growth factor beta1 (TGFbeta1) in a cell-free system and in activated hepatic stellate cells (HSCs).</p><p><b>METHODS</b>The ribozyme against TGFb1 was designed with computer software. The transcripts of ribozyme, disabled ribozyme and target RNAs were prepared using the RiboMAX large scale RNA production system. The in vitro cleavage reactions were performed through incubation of 32P-labeled target RNAs with ribozyme or disabled ribozyme in different conditions. The eukaryotic expression vector encoding ribozyme and disabled ribozyme were constructed, and then transfected into HSC-T6 cells which exhibited characteristics of activated HSCs. The intracellular activity of the ribozyme was determined by detecting the ribozyme, disabled ribozyme and the TGFbeta1 expression.</p><p><b>RESULTS</b>The ribozyme cleaved target RNAs into anticipated products effectively. As expected, the disabled ribozyme possessed no cleavage activity in vitro. Further study demonstrated that the ribozyme expressed efficiently and inhibited TGFbeta1 expression in activated HSCs, while the disabled ribozyme displayed only a slight effect on TGFbeta1 expression.</p><p><b>CONCLUSION</b>The ribozyme with perfect cleavage activity in the cell-free system used inhibited TGFbeta1 expression effectively in activated HSCs. This ribozyme can provide a potential therapeutic approach for liver fibrosis.</p>