p53联合Rb纳米粒局部基因治疗兔VX2肿瘤肝转移效果及安全性评价

Combination of p53 and Rb in the local nano-therapy for rabbit VX2 model of hepatic metastasis ;carcinoma：the curative effect and safety evaluation

目的：通过基因靶向技术将纳米粒与p53及Rb两种抗癌基因联合，探索其对兔VX2肿瘤肝转移癌灶的治疗效果并评价其生物安全性。方法以超液化碘油及多聚赖氨酸（PLL）修饰的羟基磷灰石纳米颗粒（nHAP）乳剂为载体，将含有野生型p53、Rb基因的重组表达质粒经肝动脉共同或者分别转运至兔VX2肿瘤肝转移灶局部，采用蛋白印迹法及原位共聚焦激光显微镜确定p53及Rb共表达蛋白的表达。通过肝功能检测评价此疗法的生物安全性。观察肿瘤生长及动物存活时间，评价疗效。结果 p53和Rb双基因纳米粒对兔肝功能无明显影响。p53和Rb双基因纳米靶向治疗比p53或Rb单基因纳米粒更能抑制肿瘤细胞的生长：1周生长率比对照组减慢约70%，2周生长率比对照组减慢约254%。相对于对照组，双基因组可延长存活期30 d。结论以PLL-nHAP为载体的基因纳米粒靶向治疗兔VX2肿瘤肝转移灶具有较强的抗肿瘤作用，p53和Rb双基因联合比单基因有更明显的治疗效果，很可能成为消化道肝转移癌新的治疗方法。

Objective Combination of nanoparticle with p53 and Rb gene therapy by gene targeting was applied to investigate its curative effect and safety evaluation on colorectal rabbit hepatic VX2 metastasis for tumor eradication and survival enhancement. Methods Recombinant expressing plasmids harboring wild type p53 and Rb were cotransferred or transferred separately to the rabbit hepatic VX2 metastasis by the emulsion of PLL-nHAP nanoplex and lipodiol through the hepatic artery in a tumor target manner. Subsequent co-expressions of p53 and Rb protein within the treated tumors were detected by Western blot and in situ analysis of confocal laser scanning microscope. The therapeutic effect was evaluated by the tumor growth velocity and the survival time of animals. Eventually, investigations of liver function were applied to evaluate the safety of the process. Results With safe procedure for the rabbits liver function, both p53 and Rb local nano-therapy showed favorable anti-tumor effects and increased animal survival time. p53＋Rb local nano-therapy could significantly inhibit hepatic VX2 metastasis and enhance the animal survival time compared with p53 local nano-therapy or Rb local nano-therapy. Local nano-therapy showed no significant influence to animal liver function. Conclusions Rb can work synergistically with p53 in the combined therapy mediated by PLL-nHAP nanoplex to augment the anti-tumor effect. The local nano-therapy with p53 and Rb is likely to be an effective and safe anti-tumor therapy for hepatic colorectal metastasis.