Identification of GRIN2D as a novel therapeutic target in pancreatic ductal adenocarcinoma

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

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.

The molecular mechanism underlying KRAS regulation on STK31 expression in pancreatic ductal adenocarcinoma

KRAS gene mutations are common in pancreatic ductal adenocarcinoma (PDAC), but targeting mutant KRAS is still challenging. Here, an endoribonuclease-prepared small interfering RNA (esiRNA) library was used to screen new kinases that play critical roles in PDAC driven by KRAS gene mutations, and serine/threonine kinase 31 (STK31) was identified and characterized as a potential therapeutic target for KRAS-mutant PDAC. Our results showed that STK31 was upregulated in KRAS-mutant PDAC patients with poor survival and highly expressed in PDAC cell lines with KRASG12D mutation. Inhibition of STK31 in KRAS-mutant cell lines significantly reduced PDAC cell growth in vitro and hindered tumor growth in vivo. Gain and loss of function experiments revealed that STK31 is a downstream target of KRAS in PDAC. A pharmacological inhibition assay showed MAPK/ERK signaling involved in STK31 regulation. The further mechanistic study validated that c-Jun, regulated by KRAS/MAPK signaling, directly modulates the transcription level of STK31 by binding to its promoter region. Through RNA sequencing, we found that the cell cycle regulators CCNB1 and CDC25C are downstream targets of STK31. Taken together, our results indicate that STK31, which is the downstream target of the KRAS/MAPK/ERK/c-Jun signaling pathway in KRAS-mutant PDAC, promotes PDAC cell growth by modulating the expression of the cell cycle regulators CCNB1 and CDC25C.

m6A-YTHDF1 Mediated Regulation of GRIN2D in Bladder Cancer Progression and Aerobic Glycolysis

The modification of N6-methyladenosine (m6A), primarily orchestrated by the reader protein YTHDF1, is a pivotal element in the post-transcriptional regulation of genes. While its role in various biological processes is well-documented, the specific impact of m6A-YTHDF1 on the regulation of GRIN2D, a gene implicated in cancer biology, particularly in the context of bladder cancer, is not thoroughly understood. Utilizing a series of bioinformatics analyses and experimental approaches, including cell culture, transfection, RT-qPCR, and western blotting, we investigated the m6A modification landscape in bladder cancer cells. The relationship between m6A-YTHDF1 and GRIN2D expression was examined, followed by functional assays to assess their roles in cancer progression and glycolytic activity. Our analysis identified a significant upregulation of m6A modification in bladder cancer tissues. YTHDF1 was found to regulate GRIN2D expression positively. Functionally, GRIN2D was implicated in promoting bladder cancer cell proliferation and enhancing aerobic glycolysis. Inhibition of the m6A-YTHDF1-GRIN2D axis resulted in the suppression of cancer progression and metabolic alterations. Through this research, we have elucidated the significant influence of the m6A-YTHDF1 axis on the modulation of GRIN2D expression, which in turn markedly impacts the progression of bladder cancer and its metabolic pathways, particularly aerobic glycolysis. Our findings uncover critical molecular dynamics within bladder cancer cells, offering a deeper understanding of its pathophysiology. Furthermore, the insights gained from this study underscore the potential of targeting the m6A-YTHDF1-GRIN2D pathway for the development of innovative therapeutic strategies in the treatment of bladder cancer.

Esketamine induces apoptosis of nasopharyngeal carcinoma cells through the PERK/CHOP pathway

Nasopharyngeal carcinoma, a malignant tumor prevalent in southeast Asia and north Africa, still lacks effective treatment. Esketamine, an N-methyl-D-aspartatic acid (NMDA) receptor (NMDAR) antagonist, is widely used in clinical anesthesia. Emerging evidence suggests that esketamine plays an important role in inhibiting tumor cell activity. However, the underlying mechanisms of esketamine on nasopharyngeal carcinoma remain unknown. In this study, we found that esketamine inhibited the proliferation and migration of nasopharyngeal carcinoma cells. Mechanically, transcriptome sequencing and subsequent verification experiments revealed that esketamine promoted the apoptosis of nasopharyngeal carcinoma cells through endoplasmic reticulum stress PERK/ATF4/CHOP signaling pathway mediated by NMDAR. Additionally, when combined with esketamine, the inhibitory effect of cisplatin on the proliferation of nasopharyngeal carcinoma cells was significantly enhanced. These findings provide new insights into future anti-nasopharyngeal carcinoma clinical strategies via targeting the NMDAR/PERK/CHOP axis alone or in combination with cisplatin.