Comparison Of Phosphoproteomic Profiles In Left- And Right-Sided Colorectal Cancers

582Background: Left- and right-sided colorectal cancers (CRCs) are different in terms of prognosis, treatment response and underlying molecular mechanisms. The aim of this study was to unravel the phosphoproteomic profiles of left- and right-sided primary CRCs and to identify potential drug targets for both primary tumor sites. Methods: In total phosphoproteomic profiles of 69 fresh-frozen biopsies, including 34 left-sided and 35 right-sided primary CRCs, were obtained by LC-MS/MS after cell lysis, digestion and phosphopeptide enrichment using anti-phosphotyrosine antibodies. MS/MS spectra were searched against a UniProt human reference proteome FASTA file using MaxQuant software. Fold changes between normalized intensities were calculated. Group comparison was performed using the R package Limma. P values below 0.01 and fold changes u003e two were considered significant and biologically relevant. Results: In total 2,840 phosphopeptides were detected in at least 5% of the samples. Of these, 36 phosphopeptides...