To explore the signaling pathways mediating Osimertinib resistance in lung cancer based on transcriptome sequencing technology and to identify potential targets for intervention.

In vitro, we constructed paired sensitive/resistant lung cancer cell lines under the first/second line treatment modes of Osimertinib, detected the expression of cell transcripts before and after drug resistance by high-throughput sequencing and screened the differentially expressed genes by R-package CORNAS, analyzed the intersection of differentially expressed genes between the two groups of paired cell lines with the help of Venny online tool, and using the DAVID Bioinformatics Resources database to perform kyoto Encyclopedia of Genes and Genomes(KEGG) signaling pathway and gene ontology(GO) function enrichment analysis on the common and unique differentially expressed genes in two drug-resistant modes, respectively. Finally, the STRING 12.0 database was used to analyze the key pathway enriched gene interactions and target molecules, and the molecular interaction network was mapped with the help of chiplot online tool.

The shared differentially expressed genes of the two paired cell lines were significantly enriched in the Cell Cycle pathway, the first-line treatment resistance-specific differentially expressed genes were enriched in the Cell Cycle and Ribosome biogenesis in eukaryotes pathway, and the second-line treatment resistance-specific differentially expressed genes were enriched in the MAPK signaling pathway; GO enrichment analysis revealed that shared differentially expressed genes were involved in cell division, and their molecular function was ATP binding, while first- and second-line treatment resistance-specific differentially expressed genes were involved in rRNA processing and inflammatory response, and their main molecular functions were RNA binding and Protein binding, respectively; Five key target molecules were screened, including CCNB1 (common), CDC25A and NOP56 (first-line drug resistance-specific), JUN and MYC (second-line drug resistance-specific).

The study identified potential acquired resistance mechanisms common and specific to first-or second-line treatment modalities of Osimertinib, providing potential therapeutic targets for overcoming Osimertinib resistance.