Objective To construct a mammalian vector encoding angiostatin kringle 5 (K5) under the control of αfetoprotein （AFP） enhancer and albumin promoter, and to observe the expression of angiostatin by introducting angiostatin gene into hepatocellular carcinoma cells through gene transfection. Methods Angiostatin cDNA was amplified from normal human eukaryotic cells by using RTPCR. Meanwhile, AFP enhancer and albumin promoter sequences were directed cloned and were inserted into vector pcDNA3.1. The recombinant vector of pcDNA3.1AFABangiostatin K5His was constructed, which contained the angiostatin K5 cDNA sequence that was under the control of the AFP enhancer and promoter. Angiostatin K5 cDNA was introduced into human AFP positive hepatocellular carcinoma cell lines with the transfected cultured cells that were mediated with Lipofectamine 2000. The expression of angiostatin K5 was analyzed by Western blot and the protein was dectected with antiHis antibody. Results The 500base pair of angiostatin K5 was in accordance with the expected sequence and the recombinant vector of pcDNA3.1AFABangiostatin K5His was also confirmed as the anticipated sequence. The expression of angiostatin K5 in AFP positive hepatocellular carcinoma cells was detected both by SDSPAGE and Western blot. Conclusion Efficient construction and expression of angiostatin K5 to AFP positive cells make it possible for antiangiogenesis therapy of human hepatocellular carcinomas, which may provide a promising approach.
ObjectiveTo observe the effects of angiostatin on the activity of extra-cellular signal-regulated protein kinase (ERK) of retinal microvascular endothelial cells of mice.MethodsAngiostatin was separated and purified by l-lysine sepharose 4B from human plasma. The primary retinal microvascular endothelial cells were divided into 4 groups: the control group, vascular endothelial growth factor (VEGF) 10 ng/ml group, angiostatin 130 μg/ml group, and VEGF (10 ng/ml) + angiostatin (130 μg/ml) group. The expression of ERK1 was assayed by Westernblotting method 1, 2, 5, 10, 15, and 30 minutes after the treatment of angiostatin.ResultsCompared with the control group, the expression of ERK-1 reduced 1 minute after treatment, reduced markedly after 10 minutes. After 30 minutes, no differences of the expression of ERK were seen between the control group and angiostatin group. The activation of ERK-1 of retinal microvascular endothelial cells occurred after stimulated by VEGF, and at the pitch at the peak after 5 minutes. The level of ERK in VEGF group increased 210% than that in the control (P＜0.05). After 30 minutes, no significant difference of the level of ERK between VEGF and the control group. And because of angiostatin, the expression of ERK-1 decreased 11.9%(1 minute)、17.9%(2 minutes)、38.7%(5 minutes)、49.3%(10 minutes) （P＜0.05）、27.9%(15 minutes)、1.12%(30 minutes) respectively.ConclusionsAngiostatin can effectively block the signal path through which VEGF transmits from outside of the cell to cellular nuclei. (Chin J Ocul Fundus Dis, 2005,21:170-173)
Objective To investigate the effect of angiostatin gene combined with somastatin on inhibiting proliferation of human pancreatic cancer cell BXPC-3 and endothelial cell of vascular ECV-304 and on inducing their apoptosis in vitro. Methods The pcDNA3/angio was transfected BXPC-3 by liposome-mediated gene transfer method. RT-PCR and Western blot were used to detect the expression of angiostatin gene. In vitro, MTT and flow cytometry (FCM) were used to detect whether angiostatin gene combined with somastatin could effect the growth inhibition of BXPC-3 and ECV-304 cells. Results Angiostatin was expressed and secreted by transfected BXPC-3. The growth of BXPC-3 was inhibited by certain concentration of somatostatin (≥10 μg/ml, P＜0.01）, which was dependent on the dose of somatostatin in a concentration extent; Simultaneity apoptosis was induced （P＜0.01）. But the growth of ECV-304 was not inhibited with somatostation （Pgt;0.05）. Angiostatin could inhibit the growth of ECV-304 and induced apoptosis （P＜0.01）, but it had no effect on the growth of BXPC-3 （Pgt;0.05）. Angiostation gene combined with somatostation could inhibit the growth both of BXPC-3 and ECV-304 （P＜0.01）, and induce apoptosis of them （P＜0.01）; but the effect couldn’t be additived. Conclusions ①Somatostatin directly inhibits the proliferation of human pancreatic cancer cells and induces apoptosis, but it doesn’t directly inhibit angiogenesiso of human pancreatic cancer. ②Angiostatin specially inhibits the proliferation of endothelial cell of vascular and induces apoptosis. Angiostatin could inhibit angiogenesis of human pancreatic cancer to induce necrosis of cancer cell.
Objective To study the effects of pcDNA3/AFP/TK/Angio fusion gene targeting therapy for human primary liver cancer in nude mice implanted with SMMC-7721. Methods Human liver cancer cell line SMMC-7721 was implanted subcutaneously in nude mice to establish experiment model. Animals bearing liver cancer were randomly divided into five groups: control group， vector group， GCV (ganciclovir) group， pcDNA3/TK/Angio group; pcDNA3/AFP/TK/Angio group. Different plasmids were directly injected into tumors and GCV was intraperitoneally administrated simultaneously according to different groups. The growth of tumors was observed and the pathology was examined as well. Serum AFP level was measured by radioimmunology, the ultrastructural change of tumor cells was studied by using electron microscopy, the expressions of MVD and VEGF were respectively detected with immunohistochemistry and the cell apoptosis in situ was detected by TUNEL. Results The success rate to establish subcutaneous implanted liver cancer model in nude mice was 100%. The tumor volume, serum AFP level, VEGF and MVD expressions of pcDNA3/TK/Angio group and pcDNA3/AFP/TK/Angio group were lower than those in control group, vector group and GCV group (P＜0.05) and more apoptosis cells could be observed. While the tumor volume, serum AFP level, VEGF and MVD expressions of pcDNA3/AFP/TK/Angio group was lower than those in pcDNA3/TK/Angio group (P＜0.05); and apoptosis index was higher than that of the latter (P＜0.05).Conclusion pcDNA3/AFP/TK/Angio fusion gene inhibits the growth of tumor remarkably and becomes a promising new biological agent to treat human primary liver cancer.
ObjectiveTo observe the effect of microincision vitrectomy assisted with intravitreaI injection of ranibizumab (IVR) in proliferative diabetic retinopathy (PDR) treatment. MethodsThis is a prospective, randomized, and comparative case series study. A total of 92 patients (92 eyes) with PDR were recruited to have microincision vitrectomy with (combined group) or without (PPV group) IVR. There are 48 eyes in the combined group and 44 eyes in the PPV group. The average operation time, iatrogenic breaks, the use of tamponade and electric coagulation, postoperative bleeding and best corrected visual acuity were comparatively analyzed among the two groups.The mean follow-up was (14.3±5.2) months. ResultsThe average operation time was (59.4±18.5) min in the combined group and (74.6±16.2) min in the PPV group. The rate of silicone oil tamponade (χ2=4.619), inert gas tamponade (χ2=4.290), electric coagulation (χ2=8.039) and iatrogenic breaks (χ2=4.330) in the combined group were significantly decreased compared with PPV group(P<0.05). The mean logMAR BCVA was 0.83±0.44 in the combined group and 1.37±0.53 in the PPV group, which significantly improved from preoperatively (t=3.257, 3.012; P<0.05). The rate of BCVA improvement in the combined group was significantly higher than that in the PPV group (t=2.972, P<0.05). The incidence of the recurrent vitreous hemorrhage was 2.1% in the combined group and 9.1% in the PPV group (χ2=6.741, P<0.05). There was no severe complication associated with surgery, such as choroidal detachment, retinal detachment and endophthal-mitis. ConclusionIVR before the microincision vitrectomy can shorten the operation time, reduce the use of electric coagulation and intraocular tamponade, and improve visual acuity for PDR patients.