Prognosis poor, immune infiltration of colon adenocarcinoma associated with low expression levels of calcium-activated chloride channel.

Abstract

The calcium-activated chloride channel (CLCA4) in colon adenocarcinoma (COAD) and immunological infiltration have not been extensively studied. This work thoroughly employed several datasets to assess the expression, prognosis, and association between immune infiltration and clinicopathological characteristics of CLCA4 in cancer, as well as look into potential signalling pathways. The human protein atlas (HPA), TIMER, UALCAN, TISIDB, GSCA, SangerBox, GeneMANIA, and LinkedOmics were among the datasets that were used. The findings demonstrated that, in comparison to normal tissues, COAD tissues had lower levels of CLCA4 expression. The prognosis was worse for those whose levels of CLCA4 expression were lower. For validation, immunohistochemistry (HPA) was used. Positive correlations between CLCA4 mRNA expression and its copy number variation (CNV) were observed, and CLCA4 CNV was linked to immunological infiltration. Subsequent investigation demonstrated the association between immune cell markers, immune checkpoint genes, and immunological infiltration with CLCA4. The overall survival and disease-free survival of M0 patients were considerably better than those of M1 patients, and the groups with tumour stages M0 and M1 had notably different levels of CLCA4 expression. Its substantial enrichment in ion channel activity, transmembrane transporter activity, digestion, and other biological processes was revealed by gene ontology analysis. Oxidative phosphorylation, pancreatic secretion, Parkinson's and Alzheimer's diseases, renin secretion, and other signalling pathways were the primary associations found for CLCA4. It is evident that the immunological microenvironment and functions like ion transport, metabolism, and intestinal digestion are all impacted by CLCA4 expression.