Objective To explore the effect of Tie-2 small interference RNA (siRNA) treatment in human hepatoma transplanted subcutaneously in nude mice. Methods Tumor cells were implanted in the hind flank of male nude mice of 6 weeks. Tumor-bearing mice were divided into two groups （gene therapy group and control group） and injected intra-tumorally with Tie-2-siRNA/Lipofectamine and saline/Lipofectamine respectively. The tumor volume and weight, serum AFP and microvessel density (MVD) and the histological change of the tumor were tested after gene therapy. Results The growth inhibitory rates in gene therapy group were 26.94%， 53.01% and 68.91% on day 4， 7 and 10 after gene therapy respectively. The tumor volumes of gene therapy group (118.47, 111.57 and 104.59 mm3) were smaller than those of the control group (162.17, 237.46 and 336.41 mm3) respectively (P＜0.01), and the weight of tumor in gene therapy group was lighter than that of the control group 〔(0.89±0.09) g vs (1.24±0.03), P＜0.01〕. The AFP value in gene therapy group was obviously lower than that of the control group 〔(107.66±24.13) ng/ml vs (266.08±50.96) ng/ml, P＜0.01〕. There was significant diference of MVD between the gene therapy group (34.63±4.07) and the control group (81.01±9.44) with the method of immunohistochemitry (P＜0.01). Histopathology in the control group showed that the tumor volumes were bigger, and a high atypic of tumor cells were seen. The main pathological changes in tumor tissue of gene therapy group were necrosis, there were massive necrosis. The apoptosis cells were seen in the both of necrosis and non-necrosis areas in only 2 mice of gene therapy group. Conclusion Tie-2-siRNA inhibits the tumor growth and tumor angiogenesis， and is a possible new approach for liver neoplasm gene therapy.
This study aims to investigate the effects of small interference RNA (siRNA) targeting PML-RARα mRNA on the activity of the acute promyelocytic leukemia cell line NB4. The proliferation inhibition was evaluated by MTT assay and colony-formation inhibiting test. Apoptosis was determined by flow cytometry after siRNA treatment. The results showed that the cell growth of siRNA treated group was inhibited, and the apoptosis of NB4 could be induced. The siRNA targeting PML-RARα mRNA might be a valid therapy of acute promyelocytic leukemia.