超声造影剂无创性介导P53基因治疗肝癌的探讨

目的探讨超声破坏造影剂微气泡介导人野生型P53基因治疗大鼠肝癌的效果.方法将24只患有原位肝癌的Wistar大鼠随机分为4组:第1组:仅经股静脉注入P53质粒;第2组:输入P53质粒后,立刻用二次谐波超声经体表照射瘤区;第3组:注入造影剂和P53基因后不行超声照射;第4组:注入造影剂和基因后,立刻用超声照射瘤区. 48 h后用半定量RT-PCR法检测肝癌细胞、肺、肾细胞内P53 mRNA的相对表达量.结果 RT-PCR检测各实验组细胞内均有P53 mRNA的表达.第4组肝癌细胞内的基因表达量最高,与第1、2、3组间有显著性差异(P＜0.001);第2组与第1、3 组间有显著性差异(P＜0.05).超声照射的肝癌细胞内P53基因表达量增大,而未行超声照射的肝、肾细胞内则没有显著性变化.结论经外周静脉注入超声造影剂和治疗基因后用超声照射靶组织,是一种无创、高效、安全的靶向性基因导入技术.

Non-invasive Delivery of Human Wild-type P53 Plasmid to Liver Cancer Mediated by Ultrasonic Contrast Agents

Objective To evaluate whether gene expression of human wild-type P53 plasmid in rat liver cancer could be promoted by ultrasound-mediated microbubble destruction.Methods A total of 24 rats bearing liver cancer were divided into 4 groupsAfter P53 plasmid was injected into the femoral vein,the tumor was not irradiated by ultrasound in second harmonic mode in group 1 and was done in group 2Ultrasonic contrast agents and plasmid DNA was administrated without ultrasound exposure in liver cancer in group 3 and with the exposure in group 4After 48 hours,semiquantitative RT-PCR was used to detect P53 mRNA expression in cells of liver cancer,lung and kidney.Results Expressions of P53 mRNA were detected by RT-PCR reaction in all groupsGene expression of the liver cancer cells in group 4 was the highest and was significantly different from other groups(P<0001),and the expression in group 2 was also higher than in othersBut there was no obvious change in expression of P53 plasmid in cells of lung and kidney without ultrasound exposure.Conclusions Ultrasound irradiation of echo contrast agents and therapeutic gene following intravenous administration could target theapeutic gene delivery to the region of interest,and was a noninvasive ,more efficient and safe method of gene introduction