Gene expression profile of 31 RAS/RAF-wild-type colorectal cancer (CRC) stem-cell (SC) spheroids and 7 FGFR-inhibitor resistant CSC-SC spheroids

This study investigated mechanisms of acquired resistance to FGFR inhibitor therapy in RAS/RAF–wild-type colorectal cancer (CRC). RNA sequencing (RNA-seq) data from 47 RAS/RAF-wild-type colorectal cancer stem-cell (CRC-SC) spheroid lines previously deposited under GSE205787 were integrated with newly generated RNA-seq data from 31 additional RAS/RAF-wild-type CRC-SC spheroid lines and seven FGFR inhibitor-resistant CRC-SC derivatives. The resistant derivatives were established from parental CRC-SC spheroid lines by continuous exposure to erdafitinib or futibatinib. Comparative transcriptomic analysis between matched parental and resistant lines revealed consistent upregulation of EGFR and downregulation of PTPROt, a truncated isoform of PTPRO, in resistant derivatives. Gene set enrichment analysis further indicated activation of EGFR-related signaling pathways in FGFR inhibitor-resistant spheroids. In addition, the integrated RNA-seq dataset comprising 78 RAS/RAF-wild-type CRC-SC lines was used to validate the inverse correlation between EGFR and PTPRO mRNA expression, supporting the involvement of PTPROt downregulation and EGFR pathway activation in acquired resistance to FGFR inhibition.