Fig. 4

Osimertinib treatment of PC-9 Luc⁺ orthotopic tumor-bearing mice and tumor cell isolation from micro-metastases. PC-9 Luc⁺ cells were injected into the tail vein of NSG mice. Starting on day 21 after tumor cell injection and until the end of the experiment, mice were treated with increasing doses of osimertinib from 1 mg/kg to 15 mg/kg by ip injection 5 days per week. a PC-9 Luc⁺ tumor-bearing mice were evaluated by bioluminescence. Results show the evolution of bioluminescence intensity over time and are expressed in cpm/cm² for the thoracic region (mean ± SEM, n = 3). On day 82 after tumor cell injection, the mice were euthanized, the organs that bore tumors were collected, and tumor cells were isolated to establish new cell lines. b Representative images of bioluminescence signals from PC-9 Luc⁺ tumor-bearing whole mice (top and bottom left images), lung and spine after tumor removal (top middle and right images) and backbone fragments cut soon after isolation (bottom middle image) and after being cultured for 12 days (bottom right image)