Fig. 2. 5-FU is incorporated in ribosomes of cell lines and tumours.

a Schematic representation of 5-FUrd incorporation into ribosomes determined using liquid chromatography—mass spectrometry—high-resolution mass spectrometry (LC-HRMS). b, HCT116 cells were treated for 24 h with 5 to 100 µM 5-FU and 5-FUrd incorporation was determined as in a. Data are expressed as mean + /- s.d. of independent experiments (n = 3). c, Indicated cell lines were treated for 24 h with 10 µM of 5-FU and incorporation of 5-FUrd into rRNA was determined as in a. Data are expressed as mean + /- s.d. of independent experiments (n = 3). d–f, d, HCT116, e, HT29 or f, SW480 cells were xenografted into nude mice, and mice were treated with 50 mg/kg of 5-FU twice a week (5-FU) or with PBS (Control). Incorporation of 5-FUrd into rRNA was determined as in a, from gel-purified rRNA. Data are values for individual animals (noted M1 to M3) (n = 1). g, rRNA were purified from total RNA extracted from colorectal cancer samples. Incorporation of 5-FUrd into rRNA was determined as in a. Pt = sample from 5-FU treated patient, CT Pt = sample from patient not treated with 5-FU. n = 1 for each sample. Source data are provided as a Source Data file.