Integrative analyses identify HIF-1 alpha as a potential protective role with immune cell infiltration in adamantinomatous craniopharyngioma

Craniopharyngiomas (CPs) are histologically benign tumors located in the sellar-suprasellar region. Although the transcriptome development in recent years have deepened our knowledge to the tumorigenesis process of adamantinomatous craniopharyngioma (ACP), the peritumoral immune infiltration of tumor is still not well understood. In this study, weighted gene coexpression network analysis (WGCNA) was applied to identify different gene modules based on clinical characteristics and gene expression, and then, the protein-protein interaction (PPI) network with the Cytohubba plug-in were performed to screen pivotal genes. In addition, immune cell infiltration (ICI) analysis was used to evaluate the immune microenvironment of ACP patients. In total, 8,568 differential expression genes were identified based on our datasets and two microarray profiles from the public database. The functional enrichment analysis revealed that upregulated genes were mainly enriched in immune-related pathways while downregulated genes were shown in the hormone and transduction of signaling pathways. The WGCNA investigated the most relevant modules, and 1,858 hub genes was detected, from which the PPI network identified 14 pivotal genes, and the Hypoxia-inducible factor 1-alpha (HIF-1 alpha) pathway including four critical genes may be involved in the development of ACP. Moreover, naive CD4+ and CD8+ T cells were decreased while specific subtypes of T cells were significantly increased in ACP patients according to ICI analysis. Validation by immunofluorescence staining revealed a higher expression of HIF-1 alpha in ACP (ACP vs. control) and adult-subtype (adult vs. children), suggesting a possible state of immune system activation. Notably, children with low HIF-1 alpha scores were related to the hypothalamus involvement and hydrocephalus symptoms. In this study, we successfully identified HIF-1 alpha as a key role in the tumorigenesis and development of ACP through comprehensive integrated analyses and systematically investigated the potential relationship with immune cells in ACP. The results may provide valuable resources for understanding the underlying mechanisms of ACP and strengthen HIF-1 alpha as a potential immunotherapeutic target in clinical application.