RNA-seq in parental and resistant non-small cell lung cancer (NSCLC) cells

Crotonylation is a crotonyl-coenzyme A (CoA)-mediated post-translational modification best known for its roles in epigenetic regulation. Histone lysine crotonylation (Kcr) has been reported to be involved in tumor-related biological functions such as DNA damage repair and immune infiltration. Here we find that abnormal reduction of histone Kcr significantly correlates with a poor response to epithelial growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in resistant models of lung cancer cell lines, and in cell line-derived xenograft (CDX) and patient-derived xenograft (PDX) models. The crotonyl-CoA-producing enzyme ACSS2 is the key regulator of the resistance-related change of crotonylation. Quantitative crotonylomic, transcriptomic and epigenomic analyses reveal that EGFR-TKI resistance is accompanied by reduced levels of histone 3 lysine 56 crotonylation (H3K56cr) on chromatin, which inhibits transcription of HNF1A and activates the PI3K/AKT signaling pathway. To uncover how histone Kcr regulates target genes and downstream signaling pathways to mediate EGFR-TKI resistance, RNA-seq was performed to analyze transcriptional changes in HCC827 and HCC827_Er cells with 3 replicates.