Xenogen ivis 100 in vivo imaging system

The assay was performed as previously described [16] (link). Briefly, 8×10⁵ cells of luciferase-labeled KYSE150luc cells were injected into the esophagus of BALB/cAnN-nu (nude) mice. The growth of the tumor was monitored by measuring the bioluminescent signal every week using the Xenogen IVIS 100 In vivo Imaging System (PerkinElmer). Mice were randomized to treatment group and control group for each treatment experiment. Drugs were administered to the mice after the tumors reached the signal of 1×10⁵ p/s/cm²/sr. For the carboplatin with paclitaxel study, 25 mg/kg carboplatin with 10 mg/kg paclitaxel was administered to the mice intraperitoneally three times per week. For the 5-FU with cisplatin study, 25 mg/kg 5-FU and 3 mg/kg cisplatin were administered to the mice intraperitoneally three times per week. For the erlotinib study, 200 mg/kg erlotinib (epidermal growth factor receptor inhibitor) was given via the oral route three times a week. The body weight of the mice was measured regularly, and the health of the mice was monitored continuously. Mice were sacrificed and the orthotopic tumors were excised for the evaluation of PD-L1 expression level by Western blotting and immunohistochemical (IHC) staining after one week of drug treatment.