人前列腺癌PC-3细胞的荧光标记及其脊椎转移动物模型的建立

Establishment of a mouse model bearing spinal metastatic human prostate cancer using fluorescence-labeled PC-3 cells

目的对人前列腺癌PC-3细胞进行绿色荧光蛋白(GFP)标记,并建立其在动物活体荧光成像系统下直接观察肿瘤生长及转移的前列腺癌脊柱转移模型。方法常规肿瘤细胞培养、传代,在细胞状态最佳时以不同病毒感染复数实行GFP慢病毒对PC-3的感染,7 d后在荧光显微镜下观察GFP在PC-3的表达情况。选取感染GFP阳性表达率最高的孔继续扩大培养,然后采用悬液注射于小鼠的下腔静脉,动物活体荧光成像系统下直接观察肿瘤生长及转移,3个月后处死荷瘤鼠,常规石蜡切片苏木素-伊红(HE)染色观察。结果经绿色荧光蛋白标记后人前列腺癌PC-3细胞在荧光显微镜下发出绿光,并可在体内、外持续稳定表达;下腔静脉注射1.5×l06转染后的前列腺癌细胞后1周即可在活体荧光成像系统下观察到腰背部有绿色荧光显像,4周时可见表达绿色荧光的肿瘤增大,肿瘤骨转移率为19%(3/16);3个月后解剖裸鼠可见有3只裸鼠腰椎有肿瘤浸润,与动物活体荧光成像系统结果一致,转移率约为19%(3/16)。结论 GFP慢病毒能够高效标记人前列腺癌PC-3细胞且不影响其生物学特性,并能够持久稳定表达;用绿色荧光蛋白标记的人前列腺癌PC-3细胞成功地建立了裸鼠脊柱骨转移模型,为进一步研究前列腺癌骨转移提供了一种简便、可行的新方法。

Objective To establish a mouse model of spinal metastasis of human prostate cancer using fluorescence-labeled PC-3 cells to allow direct observation by in vivo imaging. Methods PC-3 cells were infected with a lentivirus carrying green fluorescence protein （GFP） gene. The GFP-positive cell clone was expanded and prepared into cell suspension for injection into the inferior vena cava of nude mice. The tumor growth and metastasis in the mice was directly observed using an in vivo fluorescence imaging system. The tumor-bearing mice were sacrificed after 3 months for histological examination with HE staining. Results The labeled cells showed stable GFP expression both in vitro and in vivo. One week after cell injection, green fluorescence signals were detected by the in vivo fluorescence imaging system in the lower back of the mice, and at 4 weeks, the fluorescent tumor mass increased with a bone metastasis rate of 19% （3/16）. Dissection of the mice at 3 months revealed lumbar tumor infiltration in 3 mice, showing a consistent result with in vivo fluorescence imaging. Conclusion The nude mouse model of spinal bone metastasis of human prostate cancer established using GFP-labeled PC-3 cells facilitates further study of bone metastasis of prostate cancer.