Overexpression of Protein Phosphatase 2 Regulatory Subunit B"Alpha Promotes Glycolysis by Regulating Hexokinase 1 in Hepatocellular Carcinoma

Objective: To investigate the regulatory relationship of Protein Phosphatase 2 Regulatory Subunit B"Alpha ( PPP2R3A) and hexokinase 1 ( HK1) in glycolysis of hepatocellular carcinoma (HCC).

Methods: In HepG2 and Huh7 cells, PPP2R3A expression was silenced by small interfering RNA (siRNA) and overexpression by plasmid transfection. The PPP2R3A-related genes were searched by RNA sequencing. Glycolysis levels were measured by glucose uptake and lactate production. QRT-PCR, ELISA, western blot and immunofluorescence assay were performed to detect the changes of PPP2R3A and HK1. Cell proliferation, migration and invasion assay were used to study the roles of HK1 regulation by PPP2R3A.

Results: RNA sequencing data revealed that PPP2R3A siRNA significantly downregulated the expression of HK1. PPP2R3A gene overexpression promotes, while gene silencing suppresses, the level of HK1 and glycolysis in HCC cells. In HCC tissue samples, PPP2R3A and HK1 were colocalized in the cytoplasm, and their expression showed a positive correlation. HK1 inhibition abrogated the promotion of glycolysis, proliferation, migration and invasion by PPP2R3A overexpression in liver cancer cells.

Conclusion: Our findings showed the correlation of PPP2R3A and HK1 in the glycolysis of HCC, which reveals a new mechanism for the oncogenic roles of PPP2R3A in cancer.