Identification of the important role of CA9 in immune infiltration and prognosis in cervical cancer.

AIM: This study aimed to investigate the association between CA9 expression and the immune infiltration and prognosis of CC. MATERIALS & METHODS: The GSE9750 dataset in the GEO database, the UALCAN database, and the cBioPortal of cervical squamous cell carcinoma study were used for bioinformatic analysis, followed by validation via immunohistochemistry in clinical samples. RESULTS: Compared to normal controls, CC samples showed 1175 significantly downregulated and 698 significantly upregulated genes, respectively. Specifically, CA9 was identified among the up-regulated genes, with verification by analysis of TCGA data. The overexpression of CA9 in CC was further confirmed in clinical samples. The protein-protein interaction network results revealed that CA9 was closely associated with 12 genes, which were widely involved in cancer-related processes such as cell proliferation, migration, and metabolism. CA9 was associated with tumor histological subtypes, hypoxia scores, low immune infiltration, poor survival rate, and specific microorganisms. CONCLUSION: Our study indicated that CA9 was upregulated in CC and closely related to tumor immune microenvironment, thereby becoming an important prognostic factor for CC. This study highlights CA9 as a potential diagnostic and therapeutic target for the disease.