Xueying Zhao; Yunfan Chen; Dongli Sui; Liyuan Wang & Jin Lu

Colon adenocarcinoma (COAD) is a prevalent disease worldwide, known for its high mortality and morbidity rates. Despite this, the extent of investigation concerning the correlation between COAD's CLCA1 expression and immune cell infiltration remains insufficient. This study seeks to examine the expression and prognosis of CLCA1 in COAD, along with its relationship to the tumor immune microenvironment. These findings will offer valuable insights for clinical practitioners and contribute to the existing knowledge in the field. In order to evaluate the prognostic significance of CLCA1 in individuals diagnosed with colorectal cancers, we conducted a comprehensive analysis using univariate and multivariate Cox regression models along with receiver operating characteristic curve (ROC) analysis. This study was performed on the patient data of COAD obtained from The Cancer Genome Atlas (TCGA) database. Nomograms were developed to anticipate CLCA1 prognostic influence. Furthermore, the CLCA1 association with tumor immune infiltration, immune checkpoints, immune checkpoint blockade (ICB) response, interaction network, and functional analysis of CLCA1-related genes was analyzed. We found that Colon adenocarcinoma tissues significantly had decreased CLCA1 expression compared to healthy tissues. Furthermore, the study revealed that the group with high expression of CLCA1 demonstrated a significantly higher overall survival rate (OS) as compared to the group with low expression. Multivariate and Univariate Cox regression analysis revealed the potential of CLCA1 as a standalone risk factor for COAD. These results were confirmed using nomograms and ROC curves. In addition, protein-protein interaction (PPI) network analysis and functional gene enrichment showed that CLCA1 may be associated with functional activities such as pancreatic secretion, estrogen signaling and cAMP signaling, as well as with specific immune cell infiltration. Therefor, as a new independent predictor and potential biomarker of COAD, CLCA1 plays a crucial role in the advancement of colon cancer.

KEY WORDS: Colon adenocarcinoma; CLCA1; Bioinformatics analysis; Immune infiltration; Immune checkpoints; Survival analysis.

ZHAO, X.; CHEN, Y.; SUI, D.; WANG, L. & LU, J. Comprehensive analysis of CLCA1 expression, immune infiltration and immune checkpoints in colonadenocarcinoma. Int. J. Morphol., 41(6):1764-1774, 2023.