Combination cancer gene therapy in endostatin and suicide gene for metastatic murine mammary cancers

用含有血管抑制基因的非病毒质粒载体进行了实验性乳腺癌治疗。体外研究：内皮抑制素（endostatin, pEndo）、血管抑制素（angiostatin, pAngio）及两种融合基因（pEndo:pAngio）转染HUVECs可抑制Matrigels上的小管形成。体内研究：实验1。用BJMC3879细胞接种BALB/c小鼠后，用pEndo、pAngio、pEndo:pAngio或对照载体直接治疗乳腺肿瘤，每周1次，连续7周。pEndo组和pEndo:pAngio组在实验第1周及之后的整个研究过程中观察到肿瘤体积显著减少。pAngio组仅在第7周观察到肿瘤体积缩小。实验2。采用相同的乳腺癌模型，对pEndo与自杀基因（HSVtk/GCV）进行联合治疗。在pEndo、pHSVtk/GGCV和联合用药组中，肿瘤体积明显受到抑制。与单独治疗组相比，联合治疗组的肿瘤体积进一步受到抑制。在治疗组中，肺或淋巴结的转移也显著减少。然而，联合治疗组对转移瘤没有观察到总结性或协同效应。pEndo组和联合用药组肿瘤组织内微血管密度明显降低。所有治疗组均发现DNA合成减少和细胞凋亡升高。此外，在pEndo或联合组中，管腔内癌细胞迁移的淋巴管数量明显受到抑制。因此，我们得出结论，内皮抑素基因通过体内电基因转移可以抑制乳腺肿瘤的生长和转移。此外，内皮抑素与HSVtk/GCV联合治疗进一步抑制肿瘤生长，但未观察到对减少转移的总结性作用。

Experimental mammary cancer therapy in mice was conducted with electrogene transfer of a non-viral plasmid vector containing angiostatic genes. In vitro study : HUVECs transfected with endostatin (pEndo), angiostatin (pAngio) and both fusion genes (pEndo:pAngio) were inhibited the tubular formation on Matrigels. In vivo study : Experiment 1. Mammary tumors induced by inoculation of BALB/c mice with BJMC3879 cells were subsequently treated by direct injection of pEndo,pAngio,pEndo:pAngio or control vector once a week for 7 weeks. Significantly reduced tumor volumes were observed for the pEndo or pEndo:pAngio groups in experimental week 1 and thereafter throughout the study. In the pAngio group, reduced tumor volume was only observed in week 7. Experiment 2. Using the same mammary cancer model, combination therapy in pEndo with suicide gene (HSVtk/GCV) was conducted. Tumor volumes were significantly suppressed in the pEndo,pHSVtk/GGCV and the combination groups. In the combination group, the tumor volumes were further suppressed as compared with respective alone treatment groups. In therapeutic groups, metastases to lungs or lymph nodes were also significantly decreased. However, summative or synergistic effects were not observed in the combination group on metastases. Microvessel density within tumor tissues was significantly decreased in the pEndo or the combination groups. Decreased DNA synthesis and elevated apoptosis were also found in all therapeutic groups. in addition, numbers of lymphatic vessels with migrating cancer cells in their lumens were significantly inhibited in pEndo or the combination groups. We therefore conclude that endostatin gene with in vivo electrogene transfer can result in suppression of mammary tumor growth and metastases. In addition, endostatin in combination therapy with HSVtk/GCV further suppressed tumor growth but summative effects were not observed on reduction of metastases.