AIM: To study the effectiveness and mechanisms of anti-human vascular endothelial growth factor (hVEGF) hairpin ribozyme on angiogenesis,oncogenicity and tumor growth in a hepatocarcinoma cell line and a xenografted m...AIM: To study the effectiveness and mechanisms of anti-human vascular endothelial growth factor (hVEGF) hairpin ribozyme on angiogenesis,oncogenicity and tumor growth in a hepatocarcinoma cell line and a xenografted model. METHODS: The artificial anti-hVEGF hairpin ribozyme was transfected into hepatocarcinoma cell line SMMC-7721 and,subsequently,polymerase chain reaction (PCR) and reverse transcription polymerase chain reaction (RT-PCR) were performed to confirm the ribozyme gene integration and transcription. To determine the effects of ribozyme ,VEGF expression was detected by semiquantitative RT-PCR and enzyme liked immunosorbent assay (ELISA). MTT assay was carried out to measure the cell proliferation. Furthermore,the transfected and control cells were inoculated into nude mice respectively,the growth of cells in nude mice and angiogenesis were observed. RESULTS: VEGF expression was down-regulated sharply by ribozyme in transfected SMMC-7721 cells and xenografted tumor. Compared to the control group,the transfected cells grew slower in cell cultures and xenografts,and the xenograft formation was delayed as well. In addition,the microvessel density of the xenografted tumor was obviously declined in the transfected group. As demonstratedby microscopy,reduction of VEGF production induced by ribozyme resulted in a significantly higher cell differentiation and less proliferation vigor in xenografted tumor. CONCLUSION: Anti-hVEGF hairpin ribozyme can effectively inhibit VEGF expression and growth of hepatocarcinoma in vitro and in vivo. VEGF is functionally related to cell proliferation,differentiation and tumori-genesis in hepatocarcinoma.展开更多
To study the preparation and cleavage of hairpin ribozyme (HpRz) directed against the transcript of HBV core region in vitro, HRz gene designed by computer targeting the transcript of HBV core gene was cloned into the...To study the preparation and cleavage of hairpin ribozyme (HpRz) directed against the transcript of HBV core region in vitro, HRz gene designed by computer targeting the transcript of HBV core gene was cloned into the vector p1.5 between 5′-cis-Rz and 3′-cis-Rz. 32 P-labeled HpRz transcript proved whether the vector fit for the preparation of hairpin ribozyme. 32 P -labeled pKC transcript containing HBV core region as targets-RNA was transcribed by using T 7 RNA polymerase and purified by PAGE. Cold HpRz transcript was incubated with 32 P-labeled target-RNAs under different conditions and radioautographed after denaturing polyacrylamide gel electrophoresis. The results showed that HpRz had the ability of cleavage at 37 ℃ and 12 mmol/L MgCl 2 and the design of ribozyme was correct. It is concluded that HpRz prepared in vitro possesses specific catalytic activity, indicating that it is possible for HpRz to intracellularly inhibit the replication of HBV. It may be developed into a nucleic acid drug in the treatment of hepatitis B in the future.展开更多
基金Supported by the Grant from Calling for Tenders by Key Subject of Jiangsu Province, No. WK200221
文摘AIM: To study the effectiveness and mechanisms of anti-human vascular endothelial growth factor (hVEGF) hairpin ribozyme on angiogenesis,oncogenicity and tumor growth in a hepatocarcinoma cell line and a xenografted model. METHODS: The artificial anti-hVEGF hairpin ribozyme was transfected into hepatocarcinoma cell line SMMC-7721 and,subsequently,polymerase chain reaction (PCR) and reverse transcription polymerase chain reaction (RT-PCR) were performed to confirm the ribozyme gene integration and transcription. To determine the effects of ribozyme ,VEGF expression was detected by semiquantitative RT-PCR and enzyme liked immunosorbent assay (ELISA). MTT assay was carried out to measure the cell proliferation. Furthermore,the transfected and control cells were inoculated into nude mice respectively,the growth of cells in nude mice and angiogenesis were observed. RESULTS: VEGF expression was down-regulated sharply by ribozyme in transfected SMMC-7721 cells and xenografted tumor. Compared to the control group,the transfected cells grew slower in cell cultures and xenografts,and the xenograft formation was delayed as well. In addition,the microvessel density of the xenografted tumor was obviously declined in the transfected group. As demonstratedby microscopy,reduction of VEGF production induced by ribozyme resulted in a significantly higher cell differentiation and less proliferation vigor in xenografted tumor. CONCLUSION: Anti-hVEGF hairpin ribozyme can effectively inhibit VEGF expression and growth of hepatocarcinoma in vitro and in vivo. VEGF is functionally related to cell proliferation,differentiation and tumori-genesis in hepatocarcinoma.
基金This project was supported by a grantfrom the Ministry ofHealth (No.98- 1- 140 ) and Chinese Academy of Science(No.KJ95 1- B1- 6 10 )
文摘To study the preparation and cleavage of hairpin ribozyme (HpRz) directed against the transcript of HBV core region in vitro, HRz gene designed by computer targeting the transcript of HBV core gene was cloned into the vector p1.5 between 5′-cis-Rz and 3′-cis-Rz. 32 P-labeled HpRz transcript proved whether the vector fit for the preparation of hairpin ribozyme. 32 P -labeled pKC transcript containing HBV core region as targets-RNA was transcribed by using T 7 RNA polymerase and purified by PAGE. Cold HpRz transcript was incubated with 32 P-labeled target-RNAs under different conditions and radioautographed after denaturing polyacrylamide gel electrophoresis. The results showed that HpRz had the ability of cleavage at 37 ℃ and 12 mmol/L MgCl 2 and the design of ribozyme was correct. It is concluded that HpRz prepared in vitro possesses specific catalytic activity, indicating that it is possible for HpRz to intracellularly inhibit the replication of HBV. It may be developed into a nucleic acid drug in the treatment of hepatitis B in the future.
