Glycolytic enzyme HK2 promotes PD-L1 expression and breast cancer cell immune evasion

Immune therapies targeting the PD-1/PD-L1 pathway have been employed in the treatment of breast cancer, which requires aerobic glycolysis to sustain breast cancer cells growth. However, whether PD-L1 expression is regulated by glycolysis in breast cancer cells remains to be further elucidated. Here, we demonstrate that glycolytic enzyme hexokinase 2 (HK2) plays a crucial role in upregulating PD-L1 expression. Under high glucose conditions, HK2 acts as a protein kinase and phosphorylates I?Ba at T291 in breast cancer cells, leading to the rapid degradation of I?Ba and activation of NF-?B, which enters the nucleus and promotes PD-L1 expression. Immunohistochemistry staining of human breast cancer specimens and bioinformatics analyses reveals a positive correlation between HK2 and PD-L1 expression levels, which are inversely correlated with immune cell infiltration and survival time of breast cancer patients. These findings uncover the intrinsic and instrumental connection between aerobic glycolysis and PD-L1 expression-mediated tumor cell immune evasion and underscore the potential to target the protein kinase activity of HK2 for breast cancer treatment.

Automated summary

It has been found that glycolytic enzyme hexokinase 2 (HK2) plays a crucial role in upregulating PD-L1 expression in breast cancer cells. Under high glucose conditions, HK2 acts as a protein kinase and phosphorylates IκBa at T291, leading to the degradation of IκBa and activation of NF-κB, resulting in the promotion of PD-L1 expression. Correlation analysis shows that HK2 and PD-L1 expression levels are positively correlated with immune cell infiltration and survival time of breast cancer patients. These findings highlight the potential of targeting the protein kinase activity of HK2 for breast cancer treatment.