No abstract

Background: Crohn’s disease (CD) is a dynamic, chronic inflammatory condition that is closely related to an increased incidence of colorectal cancer (CRC). However, the underlying pathophysiology remains still unclear. The present study was planned to explore the gene-specific DNA methylation signature between the CD and CRC and, therefore, to discover potential biomarkers during the initiation and progression of CRC. Methods: DNA methylation data of CD were extracted from Gene Expression Omnibus (GEO) database, while the microarray data of CRC were collected from The Cancer Genome Atlas (TCGA). The differentially methylated genes (DMGs) were screened between diseases group and normal controls. Using the coexisted DMGs in CD and CRCs, we further performed a series of functional enrichment analyses. Then correlation analysis for DNA methylation and mRNA expression was conducted. Next, we analyzed another two independent data sets from GEO to confirm the expression levels of the hub genes between CD and CRC.Results: Totally 4301 DMGs were screened from CD samples compared with healthy control samples, while 2076 DMGs were discovered between CRC tissues and the control specimens. 180 DMGs coexisted in CD and CRC, including 72 comethylated genes. Hypermethylation genes were mostly involved in cAMP signaling pathway, chemokine signaling pathway and calcium signaling pathway. Hypomethylation genes were related to pathways as tryptophan metabolism. Correlation analysis for DNA methylation and mRNA expression data showed that 31 gene methylation status was negatively correlated with their mRNA expression. Moreover, two genes were found to associate with the initiation and progression of CD and CRC. Conclusions: Our results suggested that ISX and SULF1 gene were discovered to be related to the occurrence and development of CD and CRC, and SULF1 may function as a signature for prognosis for CD-related CRC.