Establish and authenticate an animal model for the triple negative breast cancer with high expression of PD-L1 and EGFR

摘要

Objective:To establish and authenticate an animal model for the triple negative breast cancer patients with high expression of PD-L1 and EGFR.Methods: the humanized breast cancer cell MDA-MB-231 was trypsinized and the supernatant was removed, washed twice with Hank's, and finally 1×105 cells were adjusted with physiological saline and injected into the nude mice's fat pads. The tumor's formation time, growth, infiltration and metastasis of mice were observed and recorded in detail. At the end of the 8th-week the tumor-bearing mice were killed to collect fresh cancer tissues and divide them into two after the anesthesia. The cancer tissue was soaked and fixed by 10％ formalin solution and embedded by paraffin to make about 4μm paraffin sections, utilized HE staining and immunohistochemistry to detect the expression of ER, PR, Her-2, Ki-67, EGFR and PD-L1.Results: Orthotopic injection of MDA-MB-231 cells could induce tumor formation on the 6th days. And the measuring was carried out on the 9th days; the tumor size was about (0.970 ± 0.073) cm3 at week 4, (3.280±0.145) cm3 at week 8; and there was more uniform in growth , rich in blood vessels, less necrosis and no ulcers of the tumor. HE staining indicated invasive ductal carcinoma; immunohistochemistry showed ER (-), PR (-), Her-2 (-), Ki-67 (+, 85％), EGFR (+ 90％) and PD-L1 (+ 80％).Conclusions:We successfully established and authenticated a humanized TNBC animal model with high expression of PD-L1 and EGFR , and perhaps offered an animal model to the patients' precision medicine.