Fig. 5

Reduced expression of LY6G6D and MAPK14 in response to FOLFOX therapy. A Left panel, western blot analysis of P-ERK1/2 and LY6G6D normalized to β-actin in cell extracts from HCT116 cells treated with SB203580 (5 nM) alone or in combination with trametinib. Right, histograms show the mean and SD of blots repeated three times and normalized to β-actin, *p < 0.05, **p < 0.01, ***p < 0.001. B Left, DNA methylation profile of LY6G6D promoter at days 4 and 12 following DNMT1 shRNA knockdown in HCT116 cells and control cells (CC); (β values between 0 and 1; y-axis). Right, expression profile of LY6G6D at day 12 (RNA-seq data) in cells subject to DNMT1 shRNA knockdown. p-values from t test, **p < 0.01, ***p < 0.001. C LY6G6D expression profile in the indicated CRC cell lines following DNMT1 knockdown with higher and lower shRNAs efficiencies. D Let, Dot plot for the top ranking hyper and hypo-methylated genes predicting resistance to FOLFOX therapy in our database GSE148766. Right, DNA methylation profile and overall survival analysis in Patients treated with FOLFOX therapeutic regime. E Left, CRC cell lines treated with 5-FU (GSE81006) were assessed to verify the methylation pattern at the LY6G6D locus. Histograms show the mean and SD of replicates experiments, ***p < 0.001. Right, The box plots show the expression profiles of LY6G6D and MAPK14 in primary tumour from 26 patients who were treated with oxPt and 5-FU as first-line therapy (GSE83129). The patients are classified as Responders (Resp) and non-Responders (non-Resp), respectively. Left, phosphoproteome data related to p38/MAPK14 phosphorylation extrapolated from HCT116.ctrl cells and HCT116-oxPt resistance (GSE83129). F The schematic depicts the pathways controlling LY6G6D expression, linked to tumor immunity and genotoxic cellular responses in CRC. Mucinous tumours are characterized by DNA hypermethylation and consequent reduction of LY6G6D expression. Conversely, DNA Hypomethylation and up-regulation of LY6G6D occurs in classic adenocarcinoma