The Basic Study of Multidisciplinary Treatment for Malignant Tumors using MnSOD Gene Therapy

1)我们利用转导MnSOD基因的纤维肉瘤细胞系FSA-II证实了MnSOD基因过表达增加了放疗、高温和化疗的体内效应。2)在SCID小鼠身上的实验表明，过表达MnSOD基因抑制了自发性细胞凋亡，而不会导致小鼠纤维肉瘤体内生长的改变。FSA-II)3)新建立的显微系统表明，热处理后细胞移动能力没有明显变化。4)体内电穿孔基因过表达对细胞移动能力无明显影响。5)体内电穿孔基因转染后，细胞内锰超氧化物歧化酶活性随着DNA浓度从5增加到50μg/6μ，L细胞内活性增加，并在第3天达到高峰。采用体内电穿孔技术将MnSOD基因导入C3H/He小鼠FSA-II肿瘤中。基因转染后第3天按不同剂量照射肿瘤或以44℃加热60min。采用肿瘤生长-50法和肿瘤控制剂量-50法对治疗效果进行分析，结果表明，MnSOD过表达提高了体外细胞的温度敏感性，显著降低了肿瘤的致瘤性，导致体内肿瘤生长时间显著延长。MnSOD过表达降低了肿瘤的致瘤性，也导致了体内放疗对肿瘤控制率的显著提高。

1) We confirmed that MnSOD gene overexpression increased the in vivo effects of radiotherapy, hyperthermia, and chemotherapy, using MnSOD gene-tranfected fibrosarcoma cell line, FSa-II.2) Experiments using scid mice revealed that overexpression of MnSOD gene suppressed spontaneous apoptosis without a resultant alteration in in vivo growth of the mouse fibrosarcoma, FSa-II.3) Newly developed microscopic system was available to indicate that MnSOD gene overexpression increased apoptosis after hyperthermic treatments.4) In vitro timelapse microscopic observation of cellular moving ability did not show any difference by MnSOD gene overexpression.5) Intracellular MnSOD activity following gene-transfection by in vivo electroporation increased as concentration of DNA increased from 5 to 5Oμg/6μl, and reached peak at third day after transfection.6) MnSOD gene-transfection by in vivo electroporation increased the in vivo effects of radiotherapy and hyperthermia. MnSOD gene was transfected by in vivo electroporation for FSa-II tumor in C3H/He mice. Tumors were irradiated at graded doses or heated at 44℃ for 60 min at third day after gene-transfection. The effects of treatments were analyzed by tumor growth-50 method and tumor control dose-50 method.This study indicated that MnSOD overexpression increased thermosensitivity of cells in vitro, and substantially reduces the tumorigenicity, resulting in a significant increase in tumor growth time in vivo. Reduced tumorigenicity by MnSOD overexpression also resulted in a significant increase in tumor control rate by radiotherapy in vivo.