人鼻咽癌放射抗拒移植瘤模型的建立

Establishment of a radioresistant xenograft tumor model of human nasopharyngeal carcinoma

目的建立稳定的人鼻咽癌放射抗拒移植瘤模型并观察其生长特性,为解决鼻咽癌放射抗拒提供良好的动物模型。方法将人鼻咽癌放射抗拒细胞CNE-2R、人鼻咽癌细胞CNE-2分别注入裸鼠左右后肢皮下。移植瘤生长后,隔日测量肿瘤直径,计算肿瘤体积,绘制移植瘤体积生长曲线。肿瘤直径0.8～1 cm时以X线隔日照射移植瘤,1 600 Gy分4次。计算移植瘤体积倍增时间和体积增长率。照射后2周取出移植瘤行常规病理检查,免疫组化检测增殖细胞核抗原(PCNA)的表达。结果 CNE-2R、CNE-2细胞的皮下成瘤率均为100%,建模成功。相对于CNE-2移植瘤,CNE-2R移植瘤生长速度慢,生长受照射抑制不明显;PCNA表达较低。结论相对于CNE-2移植瘤,CNE-2R移植瘤具有更强的放射抗拒性,CNE-2R裸鼠移植瘤模型是进一步研究鼻咽癌放射抗拒的有力工具。

Objective To establish a radioresistant xenograft tumor model of human nasopharyngeal carcinoma（NPC） and study its characteristics of growth, so as to supply a good model for investigating the mechanism of radioresistance. Methods Radioresistant human NPC CNE-2R cells and CNE-2 cells were subcutaneously injected into hind legs of nude mice. Diameters of subcutaneous xenograft tumors were measured with a caliper after the tumors were palpated, and volumes of the tumors were regularly calculated, then growth curve of the tumors was drawn. The tumors-bearing mice received X-ray radiation when the tumors reached 0.8-1 cm in size, 16 Gy in 4 fractions. Tumor doubling time and inhibition of the volumes of the tumors were calculated. The mice were sacrificed two weeks after irradiation and the tumor tissues were examined for histopathology. The expression of PCNA protein in xenograft tumors was detected by immunohistochemistry. Results All the xenograft tumor models of CNE-2R cells and CNE-2 cells were established successfully. Compared to the CNE-2 tumors, the CNE-2R tumors grew significantly slowly, its growth was not inhibited by irradiation; and its PCNA level was obviously lower. Conclusion The CNE-2R xenograft tumors are much radioresistant than the CNE-2 xenograft tumors, the established CNE-2R xenograft tumors model can be used as a reliable radioresistant NPC mouse model.