Xueying Zhao; Le Zhou; Yuanxia Xu; Dongli Sui & Jin Lu

The calcium-activated chloride channel (CLCA2) performs a vital function in the intricate process of tumorigenesis. Using a bioinformatics analysis system, we conducted a pan-cancer investigation on CLCA2 to explore its association with tumor prognosis and its involvement in immunology. In order to achieve this objective, we examined the prognostic significance and expression level of CLCA2 in multiple cancer types using the TIMER and Sangerbox databases. The analysis of protein interaction networks revealed proteins linked to CLCA2. To investigate the potential biological functions and enrichment pathways of CLCA2 in cancer, the SangerBox and GSCA databases were utilized. Furthermore, the expression of CLCA2 in different cancer subtypes was evaluated during the analysis. Various functional conditions of cancer cells were then compared with CLCA2 in the CancerSEA database. Using online tools like TISIDB and Assistant for Clinical Bioinformatics, the investigation explored the link between CLCA2 and immune subtypes. Additionally, it assessed immune cell infiltration as part of the analysis. In addition, the application of GDSA was employed to investigate the predictive significance of CLCA2 in relation to drug sensitivity. The research outcomes uncovered abnormal expression patterns of CLCA2 in diverse tumor categories, with its expression level demonstrating a correlation with distinct subtypes of tumors. Strong associations have been observed between enhanced patient survival rates and CLCA2 in specific tumor types. There is a noteworthy connection observed among diverse tumor types, immune cell infiltration, immune subtypes, and CLCA2. The enrichment analysis of KEGG indicates that there may exist a connection between the expression of CLCA2 and renin secretion, pancreatic secretion, as well as other pathways in pan-cancer. CLCA2 appears to primarily activate pathways such as EMT (epithelial-mesenchymal transition), RAS/MAPK, RTK, apoptosis, TSC/mTOR, and PI3K/ AKT in pan-cancer. On the other hand, it seems to inhibit pathways like cell cycle, DNA damage, hormone AR, and hormone ER. Through single-cell functional analysis, it has been confirmed that CLCA2 is associated with diverse cellular functional states, encompassing DNA repair, EMT, hypoxia, invasion, metastasis, and quiescence. Furthermore, a substantial correlation has been observed between the expression of CLCA2 and drug sensitivity towards bosutinib, tipifarnib-P1, as well as other therapeutic agents. This research affirms that various cancer types express CLCA2 and its involvement in tumor advancement and immune penetration. CLCA2 possesses the capability to function as a noteworthy biomarker and target for therapeutic intervention in diverse cancer forms.

KEY WORDS: CLCA2; Pan-cancer; Tumor immunity; Enrichment analysis; Prognosis.

ZHAO, X.; ZHOU, L.; XU, Y.; SUI, D. & LU, J. Expression and clinical significance of CLCA2 in pan-cancer. Int. J. Morphol., 42(2):387-401, 2024.