阳离子脂质体介导的反应c—myb寡核苷酸对脑胶质瘤生长的抑制作用研究

目的：观察阳离子脂质体lipofectAMINE介导的反义c-myb寡核苷酸（LipoAON)对肿瘤生长的影响。方法：取雄性Wistar大鼠48只，行脑内C6胶质瘤接种，术后6天，将携瘤大鼠随机分成LiPoAON组，反义c-myb寡核苷酸组（AON组），阳离子脂质体lipofectAMINE组（Lipo组）和生理盐水对照组（NS组），每组各12只，经大鼠右股静脉给药，间隔1天后，再次用同法经大鼠左股静脉等量给药，给药后严密观察各组大鼠饮食，四肢活动及体重变化情况，并于给药后第4天和第10天每组分别处死6只大鼠，进行肿瘤的生长情况的大体形态学观察。结果：LipoAON组在静脉给药期间及停药后的短期内其肿瘤生长被明显抑制,c-myb表达下调，而AON组，Lipo组与NS组相比，其肿瘤生长未见抑制现象，c-myb表达亦未见下调，但随着停药时间的延长，LipoAON对肿瘤的抑制作用下降，结论：（1）阳离子脂质体LipofectAMINE作为c-myb AON转移载体，使水溶性c-myb AON容易透过BBTB进入瘤内发挥治疗作用，且具有操作简单，安全，转染率高等特点；（2）LipoAON对C6胶质瘤生长有明显抑制作用，用反义技术抑制c-myb的表达在胶质瘤的治疗中具有研究前景，（3）LipoAON对胶质瘤生长的抑制作用随时间延长而下降，如何让c-myb AON在瘤内高效，持久，稳定地表达和发挥治疗作用，是值得进一步探讨的课题。

Inhibitory effect of cationic liposome-mediated antisense c-myb oligonucleotide on the growth of glioma]

OBJECTIVE: To aim at demonstrating whether cationic liposome-mediated antisense c-myb oligonucleotide(LipoAON) can inhibit the growth of C6 glioma by intravenous injection. METHODS: Intracerebral C6 glioma cells were implanted into the left caudal nucleus of forty-eight male Wistar rats. There were four groups: LipoAON(n = 12), antisense c-myb oligonucleotide (AON; n = 12), cationic liposome (Lipo; n = 12), and normal saline (NS; n = 12). Six days after tumor implantation, the above-mentioned drugs were injected into the right femoral veins of the rats respectively. Two days later, the same drugs were injected into the left femoral veins. The appetite, motor and weight of every animal were closely observed during the whole experiment. Six rats of each group were respectively killed 4 days and 10 days after the end of administration. The weight change, pathologic examination and immunohistochemical analysis of c-myb expression of the tumor were completed. RESULTS: In LipoAON group, the growth of the tumors was significantly inhibited in a short time after treatment and c-myb expression was down-regulated. But in the AON group and Lipo group, the growth of the tumors was not inhibited and c-myb expression was not down-regulated, compared with that in NS group. The inhibitory effect of LipoAON on the tumors rapidly declined with time and c-myb expression was again up-regulated. CONCLUSION: 1. Cationic liposome (LipofectAMINE) as transfection vehicle makes c-myb easily penetrate BBTB and enter the tumor. The technique is simple, safe, highly effective for the transfection of c-mybAON; 2. LipoAON has marked inhibitory effect on the growth of C6 glioma. The AON technical method for inhibiting the expression of c-myb oncogene has a research perspective in the treatment of glioma; 3. The inhibitory effect of LipoAON on the growth of glioma declines with time. The question about how to make c-myb AON have highly effective, sustained and stable expression in the tumor still requires further research.