BHLHE40-mediated transcriptional activation of GRIN2D in gastric cancer is involved in metabolic reprogramming

Abstract

Gastric cancer (GC) is the third leading cause of death in developed countries. The reprogramming of energy metabolism represents a hallmark of cancer, particularly amplified dependence on aerobic glycolysis. Here, we aimed to illustrate the functional role of glutamate ionotropic receptor N-methyl-D-aspartate type subunit 2D (GRIN2D) in the regulation of glycolysis in GC and the mechanisms involved. Differentially expressed genes were analyzed using the GEO and GEPIA databases, followed by prognostic value prediction using the Kaplan-Meier Plotter database. The effect of GRIN2D knockdown on the malignant behavior and glycolysis of GC cells was explored. GRIN2D expression was upregulated in GC cells and promoted the malignant behavior of GC cells by activating glycolysis. Class E basic helix-loop-helix protein 40 (BHLHE40) was overexpressed in GC cells and mediated transcriptional activation of GRIN2D. The anti-tumor effects of BHLHE40 knockdown on GC cells in vitro and in vivo were reversed by GRIN2D overexpression. Knockdown of GRIN2D or BHLHE40 downregulated the expression of mRNA of electron transport chain subunits and phosphorylation of p38 MARK and inhibited calcium efflux in GC cells. Overexpression of GRIN2D promoted calcium efflux, phosphorylation of p38 MARK protein, and proliferation of GES1 cells. Altogether, the findings derived from this study suggest that BHLHE40 knockdown suppresses the growth, mobility, and glycolysis of GC cells by inhibiting GRIN2D transcription and disrupting the BHLHE40/GRIN2D axis may be an attractive therapeutic strategy for GC.