Regulation of phosphoglycerate kinase 1 and its critical role in cancer

Pharmacological Inhibition of Phosphoglycerate Kinase 1 Reduces OxiDative Stress and Restores Impaired Autophagy in Experimental Acute Pancreatitis

Damage to pancreatic acinar cells (PAC) and intracellular metabolic disturbances play crucial roles in pancreatic necrosis during acute pancreatitis (AP). Phosphoglycerate kinase 1 (PGK1) is a crucial catalytic enzyme in glycolysis. However, the impact of PGK1-involving glycolysis in regulating metabolic necrosis in AP is unclear. Transcriptome analysis of pancreatic tissues revealed significant changes in the glycolysis pathway and PGK1 which positively correlated with the inflammatory response and oxidative stress injury in AP mice. Furthermore, we observed a substantial increase in PGK1 expression in damaged PAC, positively correlating with PAC necrosis. Treatment with NG52, a specific PGK1 inhibitor, ameliorated pancreatic necrosis, inflammatory damage, and oxidative stress. Transcriptomic data before and after NG52 treatment along with the Programmed Cell Death database confirmed that NG52 protected against PAC damage by rescuing impaired autophagy in AP. Additionally, the protective effect of NG52 was validated following pancreatic duct ligation. These findings underscore the involvement of PGK1 in AP pathogenesis, highlighting that PGK1 inhibition can mitigate AP-induced pancreatic necrosis, attenuate inflammatory and oxidative stress injury, and rescue impaired autophagy. Thus, the study findings suggest a promising interventional target for pancreatic necrosis, offering novel strategies for therapeutic approaches to clinical AP.

Structure, function and stability analysis on potential deleterious mutation ensemble in glyceraldehyde 3-phosphate dehydrogenase (GAPDH) for early detection of LUAD

AIMS

Lung adenocarcinoma (LUAD) is the most prominent histological subtype among the lung cancer which is a leading cause in the cancer mortality rate. High mutational and glycolytic rates are the major reported alterations in the lung cancer. Here in our study we are elucidating the structural and functional role of key glycolytic enzyme Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and associated SNPs in LUAD progression.

MATERIALS AND METHODS

Our gene expression analysis reveals high expression of GAPDH in the LUAD. In silico tools and analysis were used for the identification and characterization of the deleterious SNPs. Molecular Docking and dynamics simulations (MDS) studies characterized the structural consequences of prioritized deleterious mutations.

KEY FINDINGS

The sequence based analysis to identify SNPs in GAPDH resulted in 28 deleterious SNPs and 6 SNPs among them showed deleterious and damaging effect. The structural based analysis resulted in 2 stabilizing SNPs of rs ids rs11549328 (D39Y) and rs200102749 (S51Y) in the conserved domain. The IDR and PTM analysis of the GAPDH sequence resulted an IDR region from 191 to 194 positions with an IDR score of 0.511, 0.520, 0.517 and 0.503 with the PTM modifications.

SIGNIFICANCE

The identified deleterious SNPs (D39Y and S51Y) fall in the functional and conserved domain of GAPDH. In addition, the existence of PTMs within the IDR region of the GAPDH may contribute to its enhanced glycolytic activity in LUAD. The results of our study provide potential background deleterious mutants the pathological aspect of GAPDH in LUAD progression.

Function of a complex of p-Y42 RhoA GTPase and pyruvate kinase M2 in EGF signaling pathway in glioma cells

Epidermal growth factor (EGF) is known to be a critical stimulant for inducing the proliferation of glioma cancer cells. In our study, we observed that GST-RhoA binds to pyruvate kinase M2 (PKM2) in vitro. While EGF reduced the levels of RhoA protein, it significantly increased p-Y42 RhoA, as well as PKM1 and PKM2 in LN18 glioma cell line. We determined that RhoA undergoes degradation through ubiquitination involving SCF1 and Smurf1. Interestingly, we observed that p-Y42 RhoA binds to PKM2, while the dephosphomimetic form, RhoA Y42F, did not. Additionally, our observation revealed that PKM2 stabilized both RhoA and p-Y42 RhoA. Importantly, RhoA, p-Y42 RhoA, and PKM2, but not RhoA-GTP, were localized in the nucleus upon EGF stimulation. Knockdown of RhoA with siRNA resulted in the reduced levels of phosphoglycerate kinase1 (PGK1) and microtubule affinity-regulating kinase 4 (MARK). Furthermore, we found that the promoter of PGK1 was associated with β-catenin and YAP. Notably, p-Y42 RhoA and PKM2 co-immunoprecipitated with β-catenin and YAP. Based on these findings, we proposed a novel mechanism by which p-Y42 RhoA and PKM2, in conjunction with β-catenin and YAP, regulate PGK1 expression, contributing to the progression of glioma upon EGF.

The tale of SOX2: Focusing on lncRNA regulation in cancer progression and therapy

Long non-coding RNAs (lncRNAs) have emerged as influential contributors to diverse cellular processes, which regulate gene function and expression via multiple mechanistic pathways. Therefore, it is essential to exploit the structures and interactions of lncRNAs to comprehend their mechanistic functions within cells. A growing body of evidence has revealed that deregulated lncRNAs are involved in multiple regulations of malignant events including cell proliferation, growth, invasion, and metabolism. SRY-related high mobility group box (SOX)2, a well-recognized member of the SOX family, is commonly overexpressed in various types of cancer, contributing to tumor progression and maintenance of stemness. Emerging studies have shown that lncRNAs interact with SOX2 to remarkably contribute to carcinogenesis and disease states. This review elaborates on the crosstalk between the intricate and complicated functions of lncRNAs and SOX2 in the context of malignant diseases. We elucidate distinct molecular mechanisms that contribute to the onset/advancement of cancer, indicating that lncRNAs/SOX2 axes hold immense promise for potential therapeutic targets. Furthermore, we delve into the modalities of emerging feasible treatment options for targeting lncRNAs, highlighting the limitations of such therapies and providing novel insights into further ameliorations of targeted strategies of lncRNAs to promote the clinical implications. Translating current discoveries into clinical applications could ultimately boost improved survival and prognosis of cancer patients.

Increased heterogeneity in expression of genes associated with cancer progression and drug resistance

Fluctuations in the number of regulatory molecules and differences in timings of molecular events can generate variation in gene expression among genetically identical cells in the same environmental condition. This variation, termed as expression noise, can create differences in metabolic state and cellular functions, leading to phenotypic heterogeneity. Expression noise and phenotypic heterogeneity have been recognized as important contributors to intra-tumor heterogeneity, and have been associated with cancer growth, progression, and therapy resistance. However, how expression noise changes with cancer progression in actual cancer patients has remained poorly explored. Such an analysis, through identification of genes with increasing expression noise, can provide valuable insights into generation of intra-tumor heterogeneity, and could have important implications for understanding immune-suppression, drug tolerance and therapy resistance. In this work, we performed a genome-wide identification of changes in gene expression noise with cancer progression using single-cell RNA-seq data of lung adenocarcinoma patients at different stages of cancer. We identified 37 genes in epithelial cells that showed an increasing noise trend with cancer progression, many of which were also associated with cancer growth, EMT and therapy resistance. We found that expression of several of these genes was positively associated with expression of mitochondrial genes, suggesting an important role of mitochondria in generation of heterogeneity. In addition, we uncovered substantial differences in sample-specific noise profiles which could have implications for personalized prognosis and treatment.

The Complex of p-Tyr42 RhoA and p-p65/RelA in Response to LPS Regulates the Expression of Phosphoglycerate Kinase 1

Inflammation plays a crucial role in tumorigenesis, primarily mediated by NF-κB. RhoA GTPases are instrumental in regulating the activation of NF-κB. Specifically, the phosphorylation of Tyrosine 42 on RhoA ensures the activation of NF-κB by directly activating the IKKβ associated with IKKγ (NEMO). This study aimed to uncover the molecular mechanism through which p-Tyrosine 42 RhoA, in conjunction with NF-κB, promotes tumorigenesis. Notably, we observed that p-Tyrosine 42 RhoA co-immunoprecipitated with the p-Ser 536 p65/RelA subunit in NF-κB in response to LPS. Moreover, both p-Tyrosine 42 RhoA and p-p65/RelA translocated to the nucleus, where they formed a protein complex associated with the promoter of phosphoglycerate kinase 1 (PGK1) and regulated the expression of PGK1. In addition, p-p65/RelA and p-Tyr42 RhoA co-immunoprecipitated with p300 histone acetyltransferase. Intriguingly, PGK1 exhibited an interaction with β-catenin, PKM1 and PKM2. Of particular interest, si-PGK1 led to a reduction in the levels of β-catenin and phosphorylated pyruvate dehydrogenase A1 (p-PDHA1). We also found that PGK1 phosphorylated β-catenin at the Thr551 and Ser552 residues. These findings discovered that PGK1 may play a role in transcriptional regulation, alongside other transcription factors.