Potent antitumoral effects of a novel gene-viral therapeutic system CNHK300-mEndostatin in hepatocellular carcinoma / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The expression of therapeutic gene and its anti-tumor effects will be augmented and a synergism of oncolytic virus with the therapeutic gene is speculated. This study was undertaken to assess the anti-tumor effects of a novel gene-viral therapeutic system CNHK300-mEndostatin (CNHK300-mE) in hepatocellular carcinoma (HCC).</p><p><b>METHODS</b>A novel gene-viral therapeutic system named CNHK300-mE was constructed using the human telomerase reverse transcriptase (hTERT) promoter to drive the expression of the adenovirus E1A gene and cloning the therapeutic gene mouse endostatin into the adenovirus genome. By the tissue culture infectious dose 50 (TCID50) method and cytoviability assay, the replicative and cytolytic capabilities of CNHK300-mE in two HCC lines (HepGII and Hep3B) and one normal cell line (MRC-5) were analyzed, and the transgene expressions of mouse endostatin in vitro and in vivo were detected by Western blotting and ELISA assay. Tumor growth suppression and anti-angiogenesis effects in vivo were investigated using nude mice xenografts model derived from SMMC-7721 HCC cells.</p><p><b>RESULTS</b>The 3296-fold replicating capacity of CNHK300-mE in HCC cell lines versus in the normal cell line at 96 hours post infection and the 25-fold effective dose for killing 50% cells (ED50) in the normal cell line versus HCC cell lines, which were both superior to ONYX-015, were observed. Tumor growth suppression of CNHK300-mE superior to either Ad-mE or ONYX-015 was demonstrated (P < 0.01) and the anti-angiogenic effects in vivo superior to Ad-mE were also observed with immunohistochemical staining of von Willebrand factor. In comparison with non-replicative adenovirus Ad-mE, the transgene expression of mE mediated by CNHK300-mE was significantly higher in vitro (P < 0.005) and in vivo (P < 0.05).</p><p><b>CONCLUSION</b>Being capable of replicating in and lysing the telomerase-positive HCC cells and mediating effective expression of the therapeutic gene in vitro and in vivo, the novel gene-viral therapeutic system CNHK300-mE is potentially effective in the treatment of HCC.</p>

CNHK200-hA-a gene-viral therapeutic system and its antitumor effect on lung cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To develop a novel vector system, which combines the advantages of the gene therapy, antiangiogenic therapy and virus therapy, and to observe its effect on lung cancer.</p><p><b>METHODS</b>Human angiostatin gene hA(k1-5) was inserted into the genome of the replicative virus specific for the tumor cells by virus recombination technology. The expression of hA(k1-5), its effect on tumor growth in vitro and in vivo were studied.</p><p><b>RESULTS</b>A new kind of gene-viral vector system, designated as CNHK200-hA(k1-5), in which the E1b55 000 gene was deleted but the E1a gene of adenovirus preserved, was constructed. The novel vector system possessed the same property as the replicative virus ONYX-015, which replicates in p53- tumor cells but not in normal cells, thus specifically kills tumor cells. In vitro, CNHK200-hA and Ad-hA both could kill A549 tumor cells but the latter needed 100 times more MOI to achieve the same amplitude of cell killing. In vivo, the therapeutic effect of CNHK200-hA on human lung cancer A549 xenograft in nude mice was significantly better than that of Ad-hA and that of tumor-replicative virus ONYX-015.</p><p><b>CONCLUSION</b>CNHK200-hA(k1-5), a novel vector is constructed in which the angiostatin gene is inserted into the genome of the replicative adenovirus cytotoxic to p53-negative tumor cells. It has the advantages of specific tumor targeting, high level gene expression in tumor cells, and potent tumoricidal activity.</p>

Gene-viral vectors: a promising way to target tumor cells and express anticancer genes simultaneously / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To develop a new kind of vector system called gene-viral vector, which combines the advantages of gene and virus therapies.</p><p><b>METHODS</b>Using recombinant technology, an anti-tumor gene was inserted into the genome of replicative virus specific for tumor cells. The cell killing effect, reporter gene expression of the green fluorescence protein, anti-tumor gene expression of mouse interleukin-12 (mIL-12) and replication of virus were observed by the methods of cell pathology, fluorescence microscopy, ELISA and electron microscopy, respectively.</p><p><b>RESULTS</b>A new kind of gene-viral vector system of adenovirus, in which the E1b-55 kD gene was deleted but the E1a gene was preserved, was constructed. The vector system, like the replicative virus ONYX-015, replicated and proliferated in tumor cells but not in normal ones. Our vector had an advantage over ONYX-015 in that it carried different kinds of anti-tumor genes to enhance its therapeutic effect. The reporter gene expression of the green fluorescence protein in tumor cells was much better than the adenovirus vector employed in conventional gene the rapy, and the expression in our vector system was as low as or even less than that in the conventional adenovirus gene therapy system. Similar results were observed in experiments with this vector system carrying the anti-tumor gene mIL-12. Replication and proliferation of the virus carrying the mIL-12 gene in tumor cells were confirmed by electron microscopy.</p><p><b>CONCLUSIONS</b>Gene-viral vectors are new vectors with an anti-tumor gene inserted into the genome of replicative virus specific for tumor cells. Because of the specific replication and proliferation of the virus in tumor cells, expression of the anti-tumor gene is increased hundreds to thousands of times. This approach takes full advantages of gene therapy and virus therapy to enhance the effect on the tumor. It overcomes the disadvantages of conventional gene therapy, such as low transfer rate, low gene expression, lack of target tropism, and low anti-tumor activity. We believe that this is a promising means for future tumor treatment.</p>