大鼠骨髓增生异常综合征基因治疗及其机制研究

Gene Therapy for Rat Myelodysplastic Syndrome(MDS) and Its Principle

目的应用反基因V—erbB寡核苷酸（ODN）产品时大鼠骨髓增生异常综合征（MDS）动物模型进行基因治疗，观察其疗效和可能的毒性反应。方法尾静脉注射或口服治疗。对42只动物应用不同给药方法和剂量进仃治疗。（1）尾静脉注射给药，以常规剂量（D）0．56mg／kg和0．5×D两个剂量对17只大鼠MDS进行治疗。并以8只未经任何治疗的MDS为对照。在2～3个月的观察期，17只大鼠MDS均有骨髓原始和早幼粒细胞百分比（％）的下降，其中，94．1％（16／17）大鼠骨髓象恢复正常或接近正常；对照组8只MDS，3只从RA发展为RAEB，4只死于内脏出血，末见逆转为正常者。（2）口服用药14只动物，分别以1×D、0．5×D和0．25×D3种不同剂量。结果仅1×D有效，其余2种剂量均无效。（3）将反基因V—erbB寡核苷酸与CpG寡核苷酸联合应用，埘MDS、AEL和AML进行尾静脉注射治疗，发现此2种寡核苷酸治疗，显效时间明显缩短。但上述方案仅对MDS和AEL有效，而时AML则无效。（4）疗效原理研究证明，反基因V—erbBODN能抑制大鼠MDS中白血病的发展，而中心错配的反基因V—erbBODN和正基因V—erbBODN则不能。结论在0．56mg／kg剂量下，此产品对大鼠MDS，不论静脉注射或口服用约均有明显的疗效，且毒性不显。治疗恢复期间大鼠平均体重增加98g且生育能力完好，说明此产品具有临床应用价值；反基因V—erbB ODN通过形成巩固三链DNA结构，抑制内源性V—erbB表达和扩增，从而显示疗效。

Objective To use antigene V -erbB ODN to treat rat MDS and to observe their therapeutic effect and possible toxity. Methods The gene therapy was performed in 42 MDS rats with different doses（D） and methods of administration. Results 17 MDS rats were injected tail-intravenously with 1 ×D and 0.5 × D（D =0,56mg/（kg · d）,and 8 MDS rats were served as control. 1 to 3 months after gene therapy, the decrease of BM blast percentages was found in all treated MDS rats. Among them 94.1% （ 16/17 ） MDS rats recovered to normal or near - normal levels,while in control 3 RA developed into RAEB, and 4 MDS died of internal bleeding and none recovered. 14 MDS rats were administrated orally with 1 × D,0.5 × D and 0.25 x D. The therapeutic effect was observed only in 1 ×D group and none in others. The conbination of V - erbB and CpG ODNs was used to treat MDS rats with tail - intravenously injection. The therapeutic effect was obtained in rat MDS and AEL but AML. Antigne V - erbB O DNs can inhibite development of leukemia in MDS,but their central mismatch ones and sense V - erbB ODNs did not. Conclussion The products had obvious therapeutic effect on rat MDS with 1 × D, regardless of yen - injection or orally administration, and did not show toxity. During the period of observation, the bodyweight of treated MDS rats increased average 98 grams and their producibility was available. This indicated that the patent products were useful in clinic. The studies on mechanism of therapeutic effect indicated that antigene V - erbB ODNs inhibited endogenous V - erbB expression and amplification by formation of stable triplex DNA struction.