Adenylate kinase 2 is a biomarker related to the prognosis of glioma and the immune microenvironment

Background: Among the brain and the other central nervous system, gliomas are the most prevalent malignant primary tumors. Adenylate kinase 2 (AK2) is generally thought to be crucial for energy metabolism and signal transduction. Several disorders are correlated with its aberrant expression. However, it is unclear what functions AK2 might have in gliomas.

Methods: We investigated the relationship between AK2 expression and clinicopathological features of glioma patients using information obtained from public databases and patient tissue microarrays. AK2 knockdown glioma cell lines were constructed to explore how AK2 affects glioma progress. The association between AK2 and the immune microenvironment in gliomas was evaluated by multiple methods.

Results: AK2 expression was higher in glioma samples than in normal brain tissues. Older patients and those with higher-grade, IDH-wildtype, 1p/19q codeletion-free, and MGMT-unmethylated tumors had higher levels of AK2 expression, linking to poor outcomes. Thus, gliomas with high AK2 expression have a worse prognosis. GO and KEGG analyses demonstrated that AK2 was relevant to cell division and DNA replication. Downregulation of AK2 suppresses cell proliferation, migration, and colony formation of glioma cell lines in vitro. AK2 expression was positively connected to the inhibitory immune checkpoints, also correlating with immune infiltration degree.

Conclusions: In this study, AK2 may be a potential biological target for more precise molecular therapy of gliomas, since its high expression is associated with worse outcomes and a more malignant immune microenvironment.