To establish osimertinib-resistant non-small cell lung cancer (NSCLC) cell line and explore its drug resistance mechanism.

The human NSCLC cell line H1975 was used as the research object, and low-concentration osimertinib was used to continuously select secondary drug-resistant cell lines. Osimertinib drug sensitivity of cells was detected by MTS method. Cell proliferation was detected by live cell workstations. Flow cytometry was used to detect cell cycle and apoptosis. Protein mass spectrometry was used to construct differentially expressed protein profiles between parental and drug-resistant cells and some resistance-related proteins were validated by real time fluorescence quantitative polymerase chain reaction (qRT-PCR) and Western blot.

Secondary drug-resistant H1975/OSI cell line were successfully established. Compared with the parental cells, the resistance index of H1975/OSI cells increased by 27.25 times (P<0.01), the cell proliferation ability decreased but the apoptosis resistance increased (P=0.01), and no new drug-resistance related gene mutation in H1975/OSI cells. Meanwhile, the differential protein expression profiles of H1975 and H1975/OSI cells were built, and 307 upregulated proteins and 295 down-regulated proteins were found in resistant cells. When fibroblast specific protein-1 (FSP1) gene with expression up-regulation was diturbed in H1975/OSI cells, the cell IC50 value of osimertinib decreased 3.51 times (P=0.02) , and when FSP1 was overexpressed in the H1975 cells, the IC50 value of osimertinib increased by 3.75 times (P<0.01).

We successfully established human NSCLC osimitinib-resistant cell line H1975/OSI. Protein differential expression profiles between H1975 and H1975/OSI was constructed successfully. It was found that FSP1 was involved in mediating the resistance of H1975/OSI to osimertinib.

Carcinoma, non-small-cell lung; Cell line, tumor; Osimertinib; Drug resistance