低频超声联合SonoVue微泡促进裸鼠基因体内转染的可行性

目的 探讨利用低频超声联合SonoVue微泡造影剂促进基因转染人前列腺癌裸鼠皮下移植瘤的可行性。方法 采用人前列腺癌PC-3细胞建立裸鼠皮下移植瘤模型，成瘤后随机分为空白组（仅注射生理盐水）、单纯质粒组（注射生理盐水和质粒混悬液）、低频超声组（注射生理盐水和质粒混悬液后超声辐照）和低频超声+微泡组（注射超声微泡造影剂和质粒混悬液后超声辐照）。超声辐照条件：功率3 W/cm²，占空比5：5，频率80 kHz，辐照10 min。基因转染3天后在激光共聚焦显微镜下观察各组绿色荧光蛋白表达情况，并分析其平均荧光强度；同时行常规病理检查，观察低频超声联合微泡辐照对组织的损伤程度。结果 4组中，仅低频超声+微泡组可见明显绿色荧光，与其他各组差异均有统计学意义（P均<0.05）；空白组、单纯质粒组和低频超声组均未见明显绿色荧光。各组均未见明显组织损伤。结论 SonoVue微泡造影剂在低频超声辐照下能够安全有效地促进pEGFP基因转染进入人前列腺癌裸鼠皮下移植瘤组织内。

Feasibility of improving in vivo gene transfer in nude mice through low-frequency ultrasound combined with SonoVue microbubbles

Objective To investigate the feasibility of improve transfection of gene to subcutaneously transplanted tumor of prostate cancer in nude mice through low-frequency ultrasound (US) combined with microbubbles. Methods Prostate cancer cell PC-3 was transplanted into nude mice to establish subcutaneously transplanted tumor models. Then the mice were randomly divided into 4 groups, i.e. blank group (saline injection alone), pEGFP only group (pEGFP and saline co-injection), low-frequency ultrasound group (pEGFP and saline injection followed by US exposure) and low-frequency ultrasound combined with microbubbles group (pEGFP and SonoVue co-injection followed by US exposure). US was applied at 80 kHz input frequency with 50% duty cycle and 3.0 W/cm² output intensity for 10 minutes. The tumors were collected on the third day after treatment. The expression of pEGFP in tumor was examined using laser scanning confocal microscope, and the average fluorescence intensity was estimated. At the same time, routine pathological examination was performed to observe the tissue damage caused by ultrasound irradition. Results Fluorescent light in low-frequency ultrasound combined with microbubbles group was obvious, which was stronger than other groups (all P<0.05). No fluorescent light was seen in other 3 groups. There was no damage of tumor tissue in all groups. Conclusion Low-frequency ultrasound combination with SonoVue microbubbles can significantly enhance transfection of pEGFP gene into nude mice of subcutaneously transplanted tumor of prostate cancer.