Exploration of establishing a metastatic nude mouse model of double-tagging papillary thyroid cancer

Abstract

Objective To obtain a thyroid cancer cell line integrated with luciferase and fluorescence, and to establish a metastatic nude mouse model of papillary thyroid cancer monitored with in vivo imaging system. Methods Lentivirus carrying recombinant plasmid containing luciferase gene and mCherry gene infected high malignant papillary thyroid cancer cell line (BHP10-3SCmice). The stable thyroid cancer cell line (BHP10-3mluc)labeled with luciferase and mCherry selected by hygromycin, analyzed for fluorescence with fluorescence microscopy and bioluminescence with in vitro analysis and in vivo imaging. 0.25 ml(5×106/ml)BHP10-3mluc cell suspension were injected into the left thigh intramuscular tissue of 5-week-old nude mice to establish BALB/C nude mice metastatic tumor model. The growth and metastasis of the tumors were monitored weekly with in vivo imaging system. The nude mice were sacrificed on the 42th day and the tissues with metastatic tumors were analyzed by fluorescent imaging ex vivo. The ectopic implanted tumors and metastatic lesions were verified by tissue sections with Hematoxylin and Eosin staining. Results BHP10-3mluc cells showed similar growth characteristics to the original BHP10-3SCmice cells and stably expressed luciferase and mCherry. At the end of the first week after ectopic implantation, the xenograft tumors were found and in the 6th week, the tumors were found to metastasized to adjacent lymph nodes and lungs, which was consistent with the results of pathology.The growth and metastasis of tumors can be accurately monitored with in vivo imaging system. Conclusions A PTC cell line stably expressing bioluciferase and fluorescence was successfully established.The nude mouse model of PTC metastatic tumor generated by intramuscular inoculation of those cells can be well monitored with in vivo imaging system, which provides ideal models for researches on tumor growth, metastasis, and drug treatment. (Chin J Endocrinol Metab, 2017, 33: 970-975) Key words: Papillary thyroid cancer; Xenograft tumor; Bioluminescent imaging in vivo; Fluorescent imaging ex vivo