AIM:To study the antitumor effect of combined genetherapy of endostatin and interleukin 12(IL-12)withpolyvinylpyrrolidone(PVP)on mouse transplantedhepatoma.METHODS:Mouse endostatin eukaryotic plasmid(pSecES)with a mouse Igκ signal sequence inside and mouse IL-12eukaryotic plasmid(pmIL-12)were transfected into BHK-21cells respectively.Endostatin and IL-12 were assayed byELISA from the supernant and used to culture endothelialcells and spleen lymphocytes individually.Proliferation ofthe latter was evaluated by MTT.H22 cells were inoculatedinto the leg muscle of mouse,which was injected intratumorallywith pSecES/PVP,pmIL-12/PVP or pSecES+pmIL-12/PVPrepeatedly.Tumor weight,serum endostatin and serumIL-12 were assayed.Tumor infiltrating lymphocytes,tumormicrovessel density and apoptosis of tumor cells were alsodisplayed by HE staining,CD31 staining and TUNEL.RESULTS:Endostatin and IL-12 were secreted aftertransfection,which could inhibit the proliferation of endothelialcells or promote the proliferation of spleen lymphocytes.Tumor growth was highly inhibited by 91.8% after injectionof pSecES+pmIL-12/PVP accompanied by higher serumendostatin and IL-12,more infiltrating lymphocytes,fewertumor vessels and more apoptosis cells compared withinjection of pSecES/PVP,pmIL-12/PVP or vector/PVP.CONCLUSION:Mouse endostatin gene and IL-12 gene canbe expressed after intratumoral injection with PVP.Angiogenesis of hepatoma can be inhibited synergisticly,lymphocytes can be activated to infiltrate,and tumor cellsare induced to apoptosis.Hepatoma can be highly inhibitedor eradiated. AIM: To study the antitumor effect of combined gene therapy of endostatin and interleukin 12 (IL-12) with polyvinylpyrrolidone (PVP) on mouse transplanted hepatoma. METHODS: Mouse endostatin eukaryotic plasmid (pSecES) with a mouse Igκ signal sequence inside and mouse IL- 12eukaryotic plasmid (pmIL-12) were transfected into BHK-21 cells respectively. Endostatin and IL-12 were assayed by ELISA from the supernant and used to culture endothelial cells and spleen lymphocytes individually. Proliferation of the latter was evaluated by MTT. H22 cells were inoculatedinto the leg muscle of mouse, which was injected intratumorally with pSecES / PVP, pmIL-12 / PVP or pSecES + pmIL-12 / PVPrepeatedly.Tumor weight, serum endostatin and serum IL-12 were assayed. Tumor infiltrating lymphocytes, tumormicrovessel density and apoptosis of tumor cells were alsodisplayed by HE staining, CD31 staining and TUNEL.RESULTS: Endostatin and IL-12 were secreted aftertransfection, which could inhibit the proliferation of endothelial cells or promote the proliferation of spleen lymphocytes. Growth growth was highly inhibited by 91.8% after injection of pSecES + pmIL-12 / PVP accompanied by higher serumendostatin and IL-12, more infiltrating lymphocytes, fewertumor vessels and more apoptosis cells compared tojection of pSecES / PVP, 12 / PVP or vector / PVP.CONCLUSION: Mouse endostatin gene and IL-12 gene can be expressed after intratumoral injection with PVP. Angiogenesis of hepatoma can be inhibited synergistically, lymphocytes can be activated to infiltrate, and tumor cells induced to apoptosis. Hepatatoma can be highly inhibitedor eradiated.