Downregulation of KRAB zinc finger proteins in 5-fluorouracil resistant colorectal cancer cells

The radio-chemotherapy with 5-fluorouracil (5-FU) is the standard of care treatment for patients with locally advanced rectal cancer (LARC) but it is only effective for a third of them. The proteomic and transcriptomic response of three colorectal cancer (CRC) cell lines to 5-FU and radiation was assessed and correlated with their genetic background. The induction of a 5-FU-resistance in those cell lines negatively affects the levels of transcripts corresponding to Krüppel-associated box (KRAB)-containing zinc finger proteins (ZFPs), the largest family of transcriptional repressors. Among nearly 350 KRAB-ZFPs, almost a quarter are down-regulated after the induction of a 5-FU-resistance including a common one between the three CRC cell lines, ZNF649, whose role is still unknown. This proteomic, transcriptomic and genomic analysis of intrinsic and acquired resistance highlights possible new mechanisms involved in resistance to treatment and therefore potential new therapeutic targets to overcome this resistance. Overall design: RNAseq analysis of radio-chemoresistance in colorectal cancer cell lines