KAT2A succinyltransferase activity-mediated 14-3-3ζ upregulation promotes β-catenin stabilization-dependent glycolysis and proliferation of pancreatic carcinoma cells

Protein succinylation mechanisms and potential targeted therapies in urinary disease

Succinylation is a relatively common post-translational modification. It occurs in the cytoplasm, mitochondria, and the nucleus, where its essential precursor, succinyl-CoA, is present, allowing for the modification of non-histone and histone proteins. In normal cells, succinylation levels are carefully regulated to sustain a dynamic balance, necessitating the involvement of various regulatory mechanisms, including non-enzymatic reactions, succinyltransferases, and desuccinylases. Among these regulatory factors, sirtuin 5, the first identified desuccinylase, plays a significant role and has been extensively researched. The level of succinylation has a significant effect on multiple metabolic pathways, including the tricarboxylic acid cycle, redox balance, and fatty acid metabolism. Dysregulated succinylation can contribute to the progression or exacerbation of various urinary diseases. Succinylation predominantly affects disease progression by altering the expression of key genes and modulating the activity of enzymes involved in vital metabolic processes. Desuccinylases primarily affect enzymes associated with Warburg's effect, thereby affecting the energy supply of tumor cells, while succinyltransferases can regulate gene transcription to alter cell phenotype, thereby involving the development of urinary diseases. Considering these effects, targeting succinylation-related enzymes to regulate metabolic pathways or gene expression may offer a promising therapeutic strategy for treating urinary diseases.

Histone modification inhibitors: An emerging frontier in thyroid Cancer therapy

Thyroid cancer (TC) is the most common endocrine cancer and is a serious health concern due to its aggressiveness and high incidence. Histone modifications affect DNA accessibility and gene transcriptional activity by altering the structure of chromatin. Abnormal histone modifications may affect genome stability and disrupt gene expression patterns, leading to many diseases, including cancer. A growing body of research suggests that histone modifications and TC progression are inextricably linked. This article discusses the impact of aberrant histone modification patterns on TC. By targeting specific histone-modifying enzymes, it may be possible to regulate gene expression and inhibit the growth of TC. Finally, we summarize the relevant histone modification inhibitors to better understand the development stage of the use of these drugs to inhibit histone-modifying enzymes in cancer treatment.

SDH defective cancers: molecular mechanisms and treatment strategies

Succinate dehydrogenase (SDH), considered as the linkage between tricarboxylic acid cycle (TCA cycle) and electron transport chain, plays a vital role in adenosine triphosphate (ATP) production and cell physiology. SDH deficiency is a notable characteristic in many cancers. Recent studies have pinpointed the dysregulation of SDH can directly result its decreased catalytic activity and the accumulation of oncometabolite succinate, promoting tumor progression in different perspectives. This article expounds the various types of SDH deficiency in tumors and the corresponding pathological features. In addition, we discuss the mechanisms through which defective SDH fosters carcinogenesis, pioneering a categorization of these mechanisms as being either succinate-dependent or independent. Since SDH-deficient and cumulative succinate are regarded as the typical features of some cancers, like gastrointestinal stromal tumors, pheochromocytomas and paragangliomas, we summarize the presented medical management of SDH-deficient tumor patients in clinical and preclinical, identifying the potential strategies for future cancer therapeutics.

OXCT1 succinylation and activation by SUCLA2 promotes ketolysis and liver tumor growth

Ketone bodies generated in hepatocytes in the adult liver are used for nonhepatic tissues as an energy source. However, ketolysis is reactivated in hepatocellular carcinoma (HCC) cells with largely unelucidated mechanisms. Here, we demonstrate that 3-oxoacid CoA-transferase 1 (OXCT1), a rate-limiting enzyme in ketolysis, interacts with SUCLA2 upon IGF1 stimulation in HCC cells. This interaction results from ERK2-mediated SUCLA2 S124 phosphorylation and subsequent PIN1-mediated cis-trans isomerization of SUCLA2. OXCT1-associated SUCLA2 generates succinyl-CoA, which not only serves as a substrate for OXCT1 but also directly succinylates OXCT1 at K421 and activates OXCT1. SUCLA2-regulated OXCT1 activation substantially enhances ketolysis, HCC cell proliferation, and tumor growth in mice. Notably, treatment with acetohydroxamic acid, an OXCT1 inhibitor used clinically for urinary infection, inhibits liver tumor growth in mice and significantly enhances lenvatinib therapy. Our findings highlight the role of SUCLA2-coupled regulation of OXCT1 succinylation in ketolysis and unveil an unprecedented strategy for treating HCC by interrupting ketolysis.

Total glucosides of paeony ameliorates chemotherapy-induced neuropathic pain by suppressing microglia pyroptosis through the inhibition of KAT2A-mediated p38 pathway activation and succinylation

Chemotherapy-induced neuropathic pain (CINP) is a prevalent side effect of chemotherapy. Total glucosides of paeony (TGP) have been shown to be effective in pain management. This study aimed to investigate the efficacy and mechanism of TGP in alleviating CINP. Sprague-Dawley rats were treated with oxaliplatin to establish CINP models, and BV2 microglia were exposed to lipopolysaccharides (LPS) to induce pyroptosis. The impact of TGP on CINP was assessed by measuring mechanical withdrawal threshold (MWT), cold pain threshold (CPT), and thermal pain threshold (TPT), as well as inflammatory factor levels. Pyroptosis was evaluated using flow cytometry, lactate dehydrogenase (LDH) release, and pyroptosis marker levels. Quantitative real-time PCR and molecular docking were employed to identify TGP targets, while phospho-kinase arrays, western blotting, and co-immunoprecipitation were used to elucidate the mechanism. Results indicated that TGP increased MWT, CPT, and TPT and inhibited inflammatory factor release in CINP rats. Furthermore, TGP suppressed LPS-induced pyroptosis and downregulated KAT2A expression in BV2 cells; this suppression was reversed by KAT2A overexpression. Mechanistically, KAT2A overexpression activated the p38 pathway and promoted p38 succinylation at K295. KAT2A knockdown inhibited pyroptosis in LPS-induced BV2 cells, an effect that was reversed by the p38 activator metformin. Additionally, the improvements in MWT, CPT, TPT, and inflammatory factor levels observed in CINP rats treated with TGP were negated by KAT2A overexpression. In conclusion, TGP alleviated CINP by suppressing microglial pyroptosis through inhibition of the KAT2A-mediated p38 pathway activation and succinylation. This study provides insights into a potential new therapeutic approach for CINP.

Succinylation modification-mediated upregulation of Sp1 promotes hepatocellular carcinoma cell proliferation

Hepatocellular carcinoma (HCC) remains one of the most prevalent malignant tumors globally, characterized by high incidence and mortality rates. Despite ongoing research, the underlying molecular mechanisms of HCC development are not yet fully understood. Utilizing bioinformatic analysis, real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR), and Western blot assays, we identified that the expression of specificity protein 1 (Sp1) was significantly elevated in HCC cells compared to normal cells. Knockdown of the Sp1 gene led to a marked reduction in the viability and clonogenic potential of HCC cells. Further investigation revealed that the succinylation level of Sp1 was also increased in HCC cells. The upregulation of Sp1 expression was attributed to its succinylation, mediated by KAT2A, with lysine (K)562 identified as the succinylation site. Additionally, KAT2A and Sp1 were found to influence the upregulation of mTOR phosphorylation. Collectively, these findings suggest that KAT2A-promoted succinylation of Sp1 enhances the proliferative capacity of HCC cells by activating the mTOR pathway, providing a theoretical foundation for potential therapeutic strategies against HCC.

Versatility of 14-3-3 proteins and their roles in bone and joint-related diseases

Bone and joint-related diseases, including osteoarthritis (OA), rheumatoid arthritis (RA), and bone tumors, pose significant health challenges due to their debilitating effects on the musculoskeletal system. 14-3-3 proteins, a family of conserved regulatory molecules, play a critical role in the pathology of these diseases. This review discusses the intricate structure and multifunctionality of 14-3-3 proteins, their regulation of signaling pathways, and their interactions with other proteins. We underscore the significance of 14-3-3 proteins in the regulation of osteoblasts, osteoclasts, chondrocytes, and bone remodeling, all key factors in the maintenance and dysfunction of bone and joint systems. Specific focus is directed toward elucidating the contribution of 14-3-3 proteins in the pathology of OA, RA, and bone malignancies, where dysregulated 14-3-3-mediated signaling cascades have been implicated in the disease processes. This review illuminates how the perturbation of 14-3-3 protein interactions can lead to the pathological manifestations observed in these disorders, including joint destruction and osteolytic activity. We highlight cutting-edge research that positions 14-3-3 proteins as potential biomarkers for disease progression and as innovative therapeutic targets, offering new avenues for disease intervention and management.

Crossing epigenetic frontiers: the intersection of novel histone modifications and diseases

Histone post-translational modifications (HPTMs), as one of the core mechanisms of epigenetic regulation, are garnering increasing attention due to their close association with the onset and progression of diseases and their potential as targeted therapeutic agents. Advances in high-throughput molecular tools and the abundance of bioinformatics data have led to the discovery of novel HPTMs which similarly affect gene expression, metabolism, and chromatin structure. Furthermore, a growing body of research has demonstrated that novel histone modifications also play crucial roles in the development and progression of various diseases, including various cancers, cardiovascular diseases, infectious diseases, psychiatric disorders, and reproductive system diseases. This review defines nine novel histone modifications: lactylation, citrullination, crotonylation, succinylation, SUMOylation, propionylation, butyrylation, 2-hydroxyisobutyrylation, and 2-hydroxybutyrylation. It comprehensively introduces the modification processes of these nine novel HPTMs, their roles in transcription, replication, DNA repair and recombination, metabolism, and chromatin structure, as well as their involvement in promoting the occurrence and development of various diseases and their clinical applications as therapeutic targets and potential biomarkers. Moreover, this review provides a detailed overview of novel HPTM inhibitors targeting various targets and their emerging strategies in the treatment of multiple diseases while offering insights into their future development prospects and challenges. Additionally, we briefly introduce novel epigenetic research techniques and their applications in the field of novel HPTM research.

Hexokinase 2 nonmetabolic function-mediated phosphorylation of IκBα enhances pancreatic ductal adenocarcinoma progression

Aberrant signaling in tumor cells induces nonmetabolic functions of some metabolic enzymes in many cellular activities. As a key glycolytic enzyme, the nonmetabolic function of hexokinase 2 (HK2) plays a role in tumor immune evasion. However, whether HK2, dependent of its nonmetabolic activity, plays a role in human pancreatic ductal adenocarcinoma (PDAC) tumorigenesis remains unclear. Here, we demonstrated that HK2 acts as a protein kinase and phosphorylates IκBα at T291 in PDAC cells, activating NF-κB, which enters the nucleus and promotes the expression of downstream targets under hypoxia. HK2 nonmetabolic activity-promoted activation of NF-κB promotes the proliferation, migration, and invasion of PDAC cells. These findings provide new insights into the multifaceted roles of HK2 in tumor development and underscore the potential of targeting HK2 protein kinase activity for PDAC treatment.

Stratifin promotes the malignant progression of HCC via binding and hyperactivating AKT signaling

Hepatocellular carcinoma (HCC) is a highly aggressive malignant tumor with limited treatment options and poor prognosis. In this study, we reveal the pivotal role of Stratifin (SFN), also recognized as 14-3-3σ, in driving HCC progression. Our investigation underscores a substantial upregulation of SFN within HCC tissues, manifesting a significant association with worse prognostic outcomes among HCC patients. In vitro and in vivo experiments reveal that SFN overexpression significantly amplifies proliferation, mitigates sorafenib-induced effects on HCC cells, and enhances tumorigenesis. While SFN silencing exerts converse effects on HCC progression. Additionally, we unveil a critical interaction between SFN and AKT, where SFN boosts AKT kinase activity by disrupting the binding of PHLPP2 and AKT, thereby intensifying the malignant progression of HCC cells. In conclusion, this study identifies the oncogenic role of SFN and elucidates the regulatory mechanism of the SFN/AKT axis in HCC, which may provide valuable insights into the mechanisms of HCC progression and potential targets for therapeutic intervention.

KAT2A Promotes the Succinylation of PKM2 to Inhibit its Activity and Accelerate Glycolysis of Gastric Cancer

Gastric cancer (GC) is one of the main causes of cancer-related death. Lysine acetyltransferases 2 A (KAT2A) is a succinyltransferase that plays an essential role in cancer development. The pyruvate kinase M2 (PKM2) is a glycolysis rate-limiting enzyme that mediates the glycolysis of cancers. This study aimed to explore the effects and mechanism of KAT2A in GC progression. The effects of biological behaviors of GC cells were evaluated by MTT, colony formation and seahorse assays. The succinylation modification was assessed by immunoprecipitation (IP). The interaction between proteins were detected by Co-IP and immunofluorescence. A pyruvate kinase activity detection kit was used to evaluate the activity of PKM2. Western blot was performed to detect the expression and oligomerization of protein. Herein, we confirmed that KAT2A was highly expressed in GC tissues and was associated with a poor prognosis. Function studies showed that knockdown of KAT2A inhibited cell proliferation and glycolytic metabolism of GC. Mechanistically, KAT2A could directly interacted with PKM2 and KAT2A silencing inhibited the succinylation of PKM2 at K475 site. In addition, the succinylation of PKM2 altered its activity rather than its protein levels. Rescue experiments showed that KAT2A promoted GC cell growth, glycolysis, and tumor growth by promoting PKM2 K475 succinylation. Taken together, KAT2A promotes the succinylation of PKM2 at K475 to inhibit PKM2 activity, thus promotes the progression of GC. Therefore, targeting KATA2 and PKM2 may provide novel strategies for the treatment of GC.

Dysregulation of protein succinylation and disease development

As a novel post-translational modification of proteins, succinylation is widely present in both prokaryotes and eukaryotes. By regulating protein translocation and activity, particularly involved in regulation of gene expression, succinylation actively participates in diverse biological processes such as cell proliferation, differentiation and metabolism. Dysregulation of succinylation is closely related to many diseases. Consequently, it has increasingly attracted attention from basic and clinical researchers. For a thorough understanding of succinylation dysregulation and its implications for disease development, such as inflammation, tumors, cardiovascular and neurological diseases, this paper provides a comprehensive review of the research progress on abnormal succinylation. This understanding of association of dysregulation of succinylation with pathological processes will provide valuable directions for disease prevention/treatment strategies as well as drug development.

Fundamental insights and molecular interactions in pancreatic cancer: Pathways to therapeutic approaches

The gastrointestinal tract can be affected by a number of diseases that pancreatic cancer (PC) is a malignant manifestation of them. The prognosis of PC patients is unfavorable and because of their diagnosis at advanced stage, the treatment of this tumor is problematic. Owing to low survival rate, there is much interest towards understanding the molecular profile of PC in an attempt in developing more effective therapeutics. The conventional therapeutics for PC include surgery, chemotherapy and radiotherapy as well as emerging immunotherapy. However, PC is still incurable and more effort should be performed. The molecular landscape of PC is an underlying factor involved in increase in progression of tumor cells. In the presence review, the newest advances in understanding the molecular and biological events in PC are discussed. The dysregulation of molecular pathways including AMPK, MAPK, STAT3, Wnt/β-catenin and non-coding RNA transcripts has been suggested as a factor in development of tumorigenesis in PC. Moreover, cell death mechanisms such as apoptosis, autophagy, ferroptosis and necroptosis demonstrate abnormal levels. The EMT and glycolysis in PC cells enhance to ensure their metastasis and proliferation. Furthermore, such abnormal changes have been used to develop corresponding pharmacological and nanotechnological therapeutics for PC.

Contributions of transcriptional noise to leukaemia evolution: KAT2A as a case-study

Transcriptional noise is proposed to participate in cell fate changes, but contributions to mammalian cell differentiation systems, including cancer, remain associative. Cancer evolution is driven by genetic variability, with modulatory or contributory participation of epigenetic variants. Accumulation of epigenetic variants enhances transcriptional noise, which can facilitate cancer cell fate transitions. Acute myeloid leukaemia (AML) is an aggressive cancer with strong epigenetic dependencies, characterized by blocked differentiation. It constitutes an attractive model to probe links between transcriptional noise and malignant cell fate regulation. Gcn5/KAT2A is a classical epigenetic transcriptional noise regulator. Its loss increases transcriptional noise and modifies cell fates in stem and AML cells. By reviewing the analysis of KAT2A-depleted pre-leukaemia and leukaemia models, I discuss that the net result of transcriptional noise is diversification of cell fates secondary to alternative transcriptional programmes. Cellular diversification can enable or hinder AML progression, respectively, by differentiation of cell types responsive to mutations, or by maladaptation of leukaemia stem cells. KAT2A-dependent noise-responsive genes participate in ribosome biogenesis and KAT2A loss destabilizes translational activity. I discuss putative contributions of perturbed translation to AML biology, and propose KAT2A loss as a model for mechanistic integration of transcriptional and translational control of noise and fate decisions. This article is part of a discussion meeting issue 'Causes and consequences of stochastic processes in development and disease'.

Integrated analysis of scRNA-seq and bulk RNA-seq reveals that GPRC5A is an important prognostic gene in pancreatic cancer and is associated with B-cell Infiltration in pancreatic cancer

Introduction

Pancreatic cancer (PC) is a malignancy with poor prognosis. This investigation aimed to determine the relevant genes that affect the prognosis of PC and investigate their relationship with immune infiltration.

Methods

: First, we acquired PC single-cell chip data from the GEO database to scrutinize dissimilarities in immune cell infiltration and differential genes between cancerous and adjacent tissues. Subsequently, we combined clinical data from TCGA to identify genes relevant to PC prognosis. Employing Cox and Lasso regression analyses, we constructed a multifactorial Cox prognostic model, which we subsequently confirmed. The prognostic gene expression in PC was authenticated using RT-PCR. Moreover, we employed the TIMER online database to examine the relationship between the expression of prognostic genes and T and B cell infiltration. Additionally, the expression of GPRC5A and its correlation with B cells infiltration and patient prognosis were ascertained in tissue chips using multiple immune fluorescence staining.

Results

The single-cell analysis unveiled dissimilarities in B-cell infiltration between cancerous and neighboring tissues. We developed a prognostic model utilizing three genes, indicating that patients with high-risk scores experienced a more unfavorable prognosis. Immune infiltration analysis revealed a significant correlation among YWHAZ, GPRC5A, and B cell immune infiltration. In tissue samples, GPRC5A exhibited substantial overexpression and a robust association with an adverse prognosis, demonstrating a positive correlation with B cell infiltration.

Conclusion

GPRC5A is an independent risk factor in PC and correlated with B cell immune infiltration in PC. These outcomes indicated that GPRC5A is a viable target for treating PC.

Succinylation modification: a potential therapeutic target in stroke

Stroke is a leading cause of mortality and disability worldwide. Ischemic cell death triggered by the compromised supply of blood oxygen and glucose is one of the major pathophysiology of stroke-induced brain injury. Impaired mitochondrial energy metabolism is observed minutes after stroke and is closely associated with the progression of neuropathology. Recently, a new type of post-translational modification, known as lysine succinylation, has been recognized to play a significant role in mitochondrial energy metabolism after ischemia. However, the role of succinylation modification in cell metabolism after stroke and its regulation are not well understood. We aimed to review the effects of succinylation on energy metabolism, reactive oxygen species generation, and neuroinflammation, as well as Sirtuin 5 mediated desuccinylation after stroke. We also highlight the potential of targeting succinylation/desuccinylation as a promising strategy for the treatment of stroke. The succinylation level is dynamically regulated by the nonenzymatic or enzymatic transfer of a succinyl group to a protein on lysine residues and the removal of succinyl catalyzed by desuccinylases. Mounting evidence has suggested that succinylation can regulate the metabolic pathway through modulating the activity or stability of metabolic enzymes. Sirtuins, especially Sirtuin 5, are characterized for their desuccinylation activity and have been recognized as a critical regulator of metabolism through desuccinylating numerous metabolic enzymes. Imbalance between succinylation and desuccinylation has been implicated in the pathophysiology of stroke. Pharmacological agents that enhance the activity of Sirtuin 5 have been employed to promote desuccinylation and improve mitochondrial metabolism, and neuroprotective effects of these agents have been observed in experimental stroke studies. However, their therapeutic efficacy in stroke patients should be validated.

Lysine acetyltransferase KAT2A modulates ferroptosis during colorectal cancer development

BACKGROUND

Histone modifications, especially the lysine acetylation, have drawn increasing attention in cancer research area. The aim of this research is to explore the molecular mechanisms underlying the regulation of lysine acetyltransferase 2 A (KAT2A) on colorectal cancer (CRC).

METHODS

Clinical samples were collected from patients with CRC. The expression and correlation between KAT2A and ferroptosis suppressor SLC7A11 and glutathione peroxidase 4 (GPX4) were measured by qPCR and Pearson correlation analysis. NCP cells were transfected with KAT2A overexpression vectors or siRNAs. The proliferation of cells was measured by CCK-8 and colony formation assay. Cell migration and invasion was analyzed by Transwell. The accumulation of lipid peroxidation, ferrous iron, and malondialdehyde (MDA) were analyzed to determine cell ferroptosis. The expression of cell metastasis biomarkers was measured by western blotting assay. Interaction between KAT2A with GPX4 gene was measured by chromatin immunoprecipitation (ChIP).

RESULTS

The KAT2A, GPX4, and SLC7A11 expression was notably elevated in tumor tissues compared with the paired non-tumor tissues from CRC patients. The expression of KAT2A showed positive correlation with GPX4 and SLC7A11. Overexpression of KAT2A recovered the cell proliferation, migration, and invasion of CRC cells that suppressed by ferroptosis inducer erastin, along with deceased levels of ROS, iron, Fe2+, and MDA. Overexpression of KAT2A suppressed E-cadherin level and increased N-cadherin, Snail, and Vimentin expression in CRC cells. KAT2A interacted with GPX4 promoter region.

CONCLUSIONS

In conclusion, our findings demonstrated that KAT2A modulates the histone acetylation of GPX4 to regulate proliferation, metastasis, and ferroptosis of CRC cells.

Protein succinylation, hepatic metabolism, and liver diseases

Succinylation is a highly conserved post-translational modification that is processed via enzymatic and non-enzymatic mechanisms. Succinylation exhibits strong effects on protein stability, enzyme activity, and transcriptional regulation. Protein succinylation is extensively present in the liver, and increasing evidence has demonstrated that succinylation is closely related to hepatic metabolism. For instance, histone acetyltransferase 1 promotes liver glycolysis, and the sirtuin 5-induced desuccinylation is involved in the regulation of the hepatic urea cycle and lipid metabolism. Therefore, the effects of succinylation on hepatic glucose, amino acid, and lipid metabolism under the action of various enzymes will be discussed in this work. In addition, how succinylases regulate the progression of different liver diseases will be reviewed, including the desuccinylation activity of sirtuin 7, which is closely associated with fatty liver disease and hepatitis, and the actions of lysine acetyltransferase 2A and histone acetyltransferase 1 that act as succinyltransferases to regulate the succinylation of target genes that influence the development of hepatocellular carcinoma. In view of the diversity and significance of protein succinylation, targeting the succinylation pathway may serve as an attractive direction for the treatment of liver diseases.

TNF-α-Induced KAT2A Impedes BMMSC Quiescence by Mediating Succinylation of the Mitophagy-Related Protein VCP

Regular quiescence and activation are important for the function of bone marrow mesenchymal stem cells (BMMSC), multipotent stem cells that are widely used in the clinic due to their capabilities in tissue repair and inflammatory disease treatment. TNF-α is previously reported to regulate BMMSC functions, including multilineage differentiation and immunoregulation. The present study demonstrates that TNF-α impedes quiescence and promotes the activation of BMMSC in vitro and in vivo. Mechanistically, the TNF-α-induced expression of KAT2A promotes the succinylation of VCP at K658, which inhibits the interaction between VCP and MFN1 and thus inhibits mitophagy. Furthermore, activated BMMSC exhibits stronger fracture repair and immunoregulation functions in vivo. This study contributes to a better understanding of the mechanisms of BMMSC quiescence and activation and to improving the effectiveness of BMMSC in clinical applications.

Role of succinylation modification in central nervous system diseases

Diseases of the central nervous system (CNS), including stroke, brain tumors, and neurodegenerative diseases, have a serious impact on human health worldwide, especially in elderly patients. The brain, which is one of the body's most metabolically dynamic organs, lacks fuel stores and therefore requires a continuous supply of energy substrates. Metabolic abnormalities are closely associated with the pathogenesis of CNS disorders. Post-translational modifications (PTMs) are essential regulatory mechanisms that affect the functions of almost all proteins. Succinylation, a broad-spectrum dynamic PTM, primarily occurs in mitochondria and plays a crucial regulatory role in various diseases. In addition to directly affecting various metabolic cycle pathways, succinylation serves as an efficient and rapid biological regulatory mechanism that establishes a connection between metabolism and proteins, thereby influencing cellular functions in CNS diseases. This review offers a comprehensive analysis of succinylation and its implications in the pathological mechanisms of CNS diseases. The objective is to outline novel strategies and targets for the prevention and treatment of CNS conditions.

Impact of Lysine Succinylation on the Biology of Fungi

Post-translational modifications (PTMs) play a crucial role in protein functionality and the control of various cellular processes and secondary metabolites (SMs) in fungi. Lysine succinylation (Ksuc) is an emerging protein PTM characterized by the addition of a succinyl group to a lysine residue, which induces substantial alteration in the chemical and structural properties of the affected protein. This chemical alteration is reversible, dynamic in nature, and evolutionarily conserved. Recent investigations of numerous proteins that undergo significant succinylation have underscored the potential significance of Ksuc in various biological processes, encompassing normal physiological functions and the development of certain pathological processes and metabolites. This review aims to elucidate the molecular mechanisms underlying Ksuc and its diverse functions in fungi. Both conventional investigation techniques and predictive tools for identifying Ksuc sites were also considered. A more profound comprehension of Ksuc and its impact on the biology of fungi have the potential to unveil new insights into post-translational modification and may pave the way for innovative approaches that can be applied across various clinical contexts in the management of mycotoxins.

Post-translational modulation of cell signalling through protein succinylation

Cells need to adapt their activities to extra- and intracellular signalling cues. To translate a received extracellular signal, cells have specific receptors that transmit the signal to downstream proteins so that it can reach the nucleus to initiate or repress gene transcription. Post-translational modifications (PTMs) of proteins are reversible or irreversible chemical modifications that help to further modulate protein activity. The most commonly observed PTMs are the phosphorylation of serine, threonine, and tyrosine residues, followed by acetylation, glycosylation, and amidation. In addition to PTMs that involve the modification of a certain amino acid (phosphorylation, hydrophobic groups for membrane localisation, or chemical groups like acylation), or the conjugation of peptides (SUMOylation, NEDDylation), structural changes such as the formation of disulphide bridge, protein cleavage or splicing can also be classified as PTMs. Recently, it was discovered that metabolites from the tricarboxylic acid (TCA) cycle are not only intermediates that support cellular metabolism but can also modify lysine residues. This has been shown for acetate, succinate, and lactate, among others. Due to the importance of mitochondria for the overall fitness of organisms, the regulatory function of such PTMs is critical for protection from aging, neurodegeneration, or cardiovascular disease. Cancer cells and activated immune cells display a phenotype of accelerated metabolic activity known as the Warburg effect. This metabolic state is characterised by enhanced glycolysis, the use of the pentose phosphate pathway as well as a disruption of the TCA cycle, ultimately causing the accumulation of metabolites like citrate, succinate, and malate. Succinate can then serve as a signalling molecule by directly interacting with proteins, by binding to its G protein-coupled receptor 91 (GPR91) and by post-translationally modifying proteins through succinylation of lysine residues, respectively. This review is focus on the process of protein succinylation and its importance in health and disease.

Epigenetic control of pancreatic cancer metastasis

Surgical resection, when combined with chemotherapy, has been shown to significantly improve the survival rate of patients with pancreatic ductal adenocarcinoma (PDAC). However, this treatment option is only feasible for a fraction of patients, as more than 50% of cases are diagnosed with metastasis. The multifaceted process of metastasis is still not fully understood, but recent data suggest that transcriptional and epigenetic plasticity play significant roles. Interfering with epigenetic reprogramming can potentially control the adaptive processes responsible for metastatic progression and therapy resistance, thereby enhancing treatment responses and preventing recurrence. This review will focus on the relevance of histone-modifying enzymes in pancreatic cancer, specifically on their impact on the metastatic cascade. Additionally, it will also provide a brief update on the current clinical developments in epigenetic therapies.

Targeting succinylation-mediated metabolic reprogramming as a potential approach for cancer therapy

Metabolic reprogramming is a common hallmark of cancers and involves alterations in many metabolic pathways during tumor initiation and progression. However, the cancer-specific modulation of metabolic reprogramming requires further elucidation. Succinylation, a newly identified protein posttranslational modification (PTM), participates in many cellular processes by transferring a succinyl group to a residue of the target protein, which is related to various pathological disorders including cancers. In recent years, there has been a gradual increase in the number of studies on the regulation of tumors by protein succinylation. Notably, accumulating evidence suggests that succinylation can mediate cancer cell metabolism by altering the structure or activity of metabolism-related proteins and plays vital roles in metabolic reprogramming. Furthermore, some antitumor drugs have been linked to succinylation-mediated tumor-associated metabolism. To better elucidate lysine succinylation mediated tumor metabolic reprogramming, this review mainly summarizes recent studies on the regulation and effects of protein succinylation in tumors, focusing on the metabolic regulation of tumorigenesis and development, which will provide new directions for cancer diagnosis as well as possible therapeutic targets.

Unveiling the role of GAS41 in cancer progression

GAS41, a member of the human YEATS domain family, plays a pivotal role in human cancer development. It serves as a highly promising epigenetic reader, facilitating precise regulation of cell growth and development by recognizing essential histone modifications, including histone acetylation, benzoylation, succinylation, and crotonylation. Functional readouts of these histone modifications often coincide with cancer progression. In addition, GAS41 functions as a novel oncogene, participating in numerous signaling pathways. Here, we summarize the epigenetic functions of GAS41 and its role in the carcinoma progression. Moving forward, elucidating the downstream target oncogenes regulated by GAS41 and the developing small molecule inhibitors based on the distinctive YEATS recognition properties will be pivotal in advancing this research field.

KHDRBS3 accelerates glycolysis and promotes malignancy of hepatocellular carcinoma via upregulating 14-3-3ζ

BACKGROUND

Primary hepatocellular carcinoma (HCC) is a malignancy with high morbidity and mortality. KH domain-containing, RNA-binding signal transduction-associated protein 3 (KHDRBS3) is an RNA-binding protein that is aberrantly expressed in multiple tumors; however, its expression and biological function in HCC have not been reported.

METHODS

KHDRBS3 knockdown and overexpression were performed using the lentiviral vector system to investigate the effects of KHDRBS3 on cell proliferation, apoptosis, chemoresistance, and glycolysis. Murine xenograft tumor models were constructed to study the role of KHDRBS3 on tumor growth in vivo. Furthermore, RNA-Pull Down and RNA immunoprecipitation were utilized to explore the interaction between KHDRBS3 and 14-3-3ζ, a phosphopeptide-binding molecule encoded by YWHAZ.

RESULTS

KHDRBS3 was highly expressed in human HCC tissues and predicted the poor prognosis of patients with HCC. Knockdown of KHDRBS3 exhibited a carcinostatic effect in HCC and impeded proliferation and tumor growth, reduced glycolysis, enhanced cell sensitivity to doxorubicin, and induced apoptosis. On the contrary, forced expression of KHDRBS3 expedited the malignant biological behaviors of HCC cells. The expression of KHDRBS3 was positively correlated with the expression of 14-3-3ζ. RNA immunoprecipitation and RNA pull-down assays demonstrated that KHDRBS3 bound to YWHAZ. We further confirmed that 14-3-3ζ silencing significantly reversed the promotion of proliferation and glycolysis and the inhibition of apoptosis caused by KHDRBS3 overexpression.

CONCLUSIONS

Our findings suggest that KHDRBS3 promotes glycolysis and malignant progression of HCC through upregulating 14-3-3ζ expression, providing a possible target for HCC therapy.

The crosstalking of lactate-Histone lactylation and tumor

Lactate was once considered to be a by-product of energy metabolism, but its unique biological value was only gradually explored with the advent of the Warburg effect. As an end product of glycolysis, lactate can act as a substrate for energy metabolism, a signal transduction molecule, a regulator of the tumor microenvironment and immune cells, and a regulator of the deubiquitination of specific enzymes, and is involved in various biological aspects of tumor regulation, including energy shuttling, growth and invasion, angiogenesis and immune escape. Furthermore, we describe a novel lactate-dependent epigenetic modification, namely histone lactylation modification, and review the progress of its study in tumors, mainly involving the reprogramming of tumor phenotypes, regulation of related gene expression, mediation of the glycolytic process in tumor stem cells (CSCs) and influence on the tumor immune microenvironment. The study of epigenetic regulation of tumor genes by histone modification is still in its infancy, and we expect that by summarizing the effects of lactate and histone modification on tumor and related gene regulation, we will clarify the scientific significance of future histone modification studies and the problems to be solved, and open up new fields for targeted tumor therapy.

Aberrant KAT2A accumulations render TRIM22-low melanoma sensitive to Notch1 inhibitors via epigenetic reprogramming

BACKGROUND

Aberrant ubiquitin-proteasome system (UPS) triggers various disorders of biological events and contributes to progression of tumorigenesis. The tripartite motif containing 22 (TRIM22) was demonstrated to participate in the progression of multiple malignancies. Nevertheless, the role of TRIM22 in melanoma is still indefinite. This project aims to investigate the biological function of TRIM22 in melanoma and provide novel therapeutical targets.

METHODS

Bioinformatic algorithms were used to investigate prognostic significance of TRIM22. The in vitro or in vivo assays were used to explore the functions of TRIM22 in melanoma. The Co-Immunoprecipitation (Co-IP) and in vivo ubiquitination assays were used to assess regulations of TRIM22 on lysine acetyltransferase 2 A (KAT2A). The Chromatin immunoprecipitation (ChIP) assays and luciferase reporter assay were utilized to explore epigenetic regulations of KAT2A on Notch1.

RESULTS

Here, we utilized the bioinformatic methods to confirm that TRIM22 is decreased in melanoma than normal tissues. Patients with low TRIM22 levels had shorter survival months than those with high TRIM22 levels. Targeting TRIM22 favors melanoma cell migration, proliferation, and tumor development in vitro and in vivo. Mechanistically, TRIM22 interacts with KAT2A and promotes its degradation in a ubiquitination-dependent manner. Melanoma cells with TRIM22 deficiency depended on KAT2A to enhance malignant progression, including proliferation, migration, and in vivo growth. KEGG analysis determined the positive correlation between KAT2A and Notch signaling. Chromatin Immunoprecipitation (ChIP) assays implicated that KAT2A directly binds to the promoter region of Notch1 and mediates the enrichment of H3K9ac modification. KAT2A activates Notch1 transcriptional levels and sustains the stemness feature of melanoma cells. Nocth1 inhibitor (IMR-1) effectively suppresses the growth of TRIM22low melanoma in vitro and in vivo but fails to inhibit TRIM22high melanoma.

CONCLUSION

Together, our study illustrates the mechanism by which the TRIM22-KAT2A-Notch1 axis promotes melanoma progression, and demonstrates that KAT2A/Nocth1 confers an epigenetic vulnerability in TRIM22low melanoma.

Succinylation-associated lncRNA signature to predict the prognosis of colon cancer based on integrative bioinformatics analysis

Colon cancer (CC) has a poor 5-year survival rate though the treatment techniques and strategies have been improved. Succinylation and long noncoding RNAs (lncRNAs) have prognostic value for CC patients. We analyzed and obtained succinylation-related lncRNA by co-expression in CC. A novel succinylation-related lncRNA model was developed by univariate and Least absolute shrinkage and selection operator (Lasso) regression analysis and we used principal component analysis (PCA), functional enrichment annotation, tumor immune environment, drug sensitivity and nomogram to verify the model, respectively. Six succinylation-related lncRNAs in our model were finally confirmed to distinguish the survival status of CC and showed statistically significant differences in training set, testing set, and entire set. The prognosis of with this model was associated with age, gender, M0 stage, N2 stage, T3 + T4 stage and Stage III + IV. The high-risk group showed a higher mutation rate than the low-risk group. We constructed a model to predict overall survival for 1-, 3-, and 5-year with AUCs of 0.694, 0.729, and 0.802, respectively. The high-risk group was sensitive to Cisplatin and Temozolomide compounds. Our study provided novel insights into the value of the succinylation-related lncRNA signature as a predictor of prognosis, which had high clinical application value in the future.

Signatures of Co-Deregulated Genes and Their Transcriptional Regulators in Kidney Cancers

There are several studies on the deregulated gene expression profiles in kidney cancer, with varying results depending on the tumor histology and other parameters. None of these, however, have identified the networks that the co-deregulated genes (co-DEGs), across different studies, create. Here, we reanalyzed 10 Gene Expression Omnibus (GEO) studies to detect and annotate co-deregulated signatures across different subtypes of kidney cancer or in single-gene perturbation experiments in kidney cancer cells and/or tissue. Using a systems biology approach, we aimed to decipher the networks they form along with their upstream regulators. Differential expression and upstream regulators, including transcription factors [MYC proto-oncogene (MYC), CCAAT enhancer binding protein delta (CEBPD), RELA proto-oncogene, NF-kB subunit (RELA), zinc finger MIZ-type containing 1 (ZMIZ1), negative elongation factor complex member E (NELFE) and Kruppel-like factor 4 (KLF4)] and protein kinases [Casein kinase 2 alpha 1 (CSNK2A1), mitogen-activated protein kinases 1 (MAPK1) and 14 (MAPK14), Sirtuin 1 (SIRT1), Cyclin dependent kinases 1 (CDK1) and 4 (CDK4), Homeodomain interacting protein kinase 2 (HIPK2) and Extracellular signal-regulated kinases 1 and 2 (ERK1/2)], were computed using the Characteristic Direction, as well as GEO2Enrichr and X2K, respectively, and further subjected to GO and KEGG pathways enrichment analyses. Furthermore, using CMap, DrugMatrix and the LINCS L1000 chemical perturbation databases, we highlight putative repurposing drugs, including Etoposide, Haloperidol, BW-B70C, Triamterene, Chlorphenesin, BRD-K79459005 and β-Estradiol 3-benzoate, among others, that may reverse the expression of the identified co-DEGs in kidney cancers. Of these, the cytotoxic effects of Etoposide, Catecholamine, Cyclosporin A, BW-B70C and Lasalocid sodium were validated in vitro. Overall, we identified critical co-DEGs across different subtypes in kidney cancer, and our results provide an innovative framework for their potential use in the future.

Aspirin modulates succinylation of PGAM1K99 to restrict the glycolysis through NF-κB/HAT1/PGAM1 signaling in liver cancer

Aspirin as a chemopreventive agent is able to restrict the tumor growth. Phosphoglycerate mutase 1 (PGAM1) is a key enzyme of glycolysis, playing an important role in the development of cancer. However, the underlying mechanism by which aspirin inhibits the proliferation of cancer cells is poorly understood. This study aims to identify the effects of aspirin on modulating PGAM1 enzymatic activities in liver cancer. Here, we found that aspirin attenuated the PGAM1 succinylation to suppress the PGAM1 enzymatic activities and glycolysis in hepatoma cells. Mechanically, aspirin remarkably reduced the global succinylation levels of hepatoma cells, including the PGAM1 succinylation, which led to the block of conversion from 3-phosphoglycerate (3-PG) to 2-phosphoglycerate (2-PG) in cells. Interestingly, RNA-seq analysis identified that aspirin could significantly decrease the levels of histone acetyltransferase 1 (HAT1), a writer of PGAM1 succinylation, in liver cancer. As a target of aspirin, NF-κB p65 could effectively up-regulate the expression of HAT1 in the system, resulting in the increase of PGAM1 enzymatic activities. Moreover, we observed that the PGAM1-K99R mutant failed to rescue the aspirin-induced inhibition of PGAM1 activities, glycolysis, and proliferation of hepatoma cells relative to PGAM1-WT. Functionally, aspirin down-regulated HAT1 and decreased the PGAM1 succinylation levels in the tumor tissues from mice treated with aspirin in vivo. Thus, we conclude that aspirin modulates PGAM1K99 succinylation to restrict the PGAM1 activities and glycolysis through NF-κB p65/HAT1/PGAM1 signaling in liver cancer. Our finding provides new insights into the mechanism by which aspirin inhibits glycolysis in hepatocellular carcinoma.

Succinylation and redox status in cancer cells

Succinylation is a post-translational modification (PTM) event that associates metabolic reprogramming with various pathological disorders including cancers via transferring a succinyl group to a residue of the target protein in an enzymic or non-enzymic manner. With our incremental knowledge on the roles of PTM played in tumor initiation and progression, relatively little has been focused on succinylation and its clinical implications. By delineating the associations of succinylation with cancer hallmarks, we identify the, in general, promotive roles of succinylation in manifesting cancer hallmarks, and conceptualize two working modes of succinylation in driving oncogenic signaling, i.e., via altering the structure and charge of target proteins towards enhanced stability and activity. We also characterize succinylation as a reflection of cellular redox homeostatic status and metabolic state, and bring forth the possible use of hyper-succinylated genome for early cancer diagnosis or disease progression indication. In addition, we propose redox modulation tools such as cold atmospheric plasma as a promising intervention approach against tumor cells and cancer stemness via targeting the redox homeostatic environment cells established under a pathological condition such as hypoxia. Taken together, we emphasize the central role of succinylation in bridging the gap between cellular metabolism and redox status, and its clinical relevance as a mark for cancer diagnosis as well as a target in onco-therapeutics.

Oncometabolites drive tumorigenesis by enhancing protein acylation: from chromosomal remodelling to nonhistone modification

Metabolites are intermediate products of cellular metabolism catalysed by various enzymes. Metabolic remodelling, as a biochemical fingerprint of cancer cells, causes abnormal metabolite accumulation. These metabolites mainly generate energy or serve as signal transduction mediators via noncovalent interactions. After the development of highly sensitive mass spectrometry technology, various metabolites were shown to covalently modify proteins via forms of lysine acylation, including lysine acetylation, crotonylation, lactylation, succinylation, propionylation, butyrylation, malonylation, glutarylation, 2-hydroxyisobutyrylation and β-hydroxybutyrylation. These modifications can regulate gene expression and intracellular signalling pathways, highlighting the extensive roles of metabolites. Lysine acetylation is not discussed in detail in this review since it has been broadly investigated. We focus on the nine aforementioned novel lysine acylations beyond acetylation, which can be classified into two categories: histone acylations and nonhistone acylations. We summarize the characteristics and common functions of these acylation types and, most importantly, provide a glimpse into their fine-tuned control of tumorigenesis and potential value in tumour diagnosis, monitoring and therapy.

A review of the mechanism of succinylation in cancer

Lysine succinylation is a novel, broad-spectrum, dynamic, non-enzymatic protein post-translational modification (PTM). Succinylation is essential for the regulation of protein function and control of various signaling and regulatory pathways. It is involved in several life activities, including glucose metabolism, amino acid metabolism, fatty acid metabolism, ketone body synthesis, and reactive oxygen species clearance, by regulating protease activity and gene expression. The level of succinylation is mainly regulated by succinyl donor, succinyltransferase, and desuccinylase. Many studies have confirmed that succinylation plays a role in tumorigenesis by creating tissue heterogeneity, and can promote or inhibit various cancers via the regulation of different substrate targets or signaling pathways. The mechanism of action of some antineoplastic drugs is related to succinylation. To better understand the role of succinylation modification in cancer development and treatment, the present study reviewed the current research content and latest progress of succinylation modification in cancer, which might provide a new direction and target for the prevention and treatment of cancer.

Catalpol induces apoptosis in breast cancer in vitro and in vivo: Involvement of mitochondria apoptosis pathway and post-translational modifications

Breast cancer is a fatal cancer with the highest mortality in female. New strategies for anti-breast cancer are still urgently needed. Catalpol, an iridoid glycoside extracted from the traditional Chinese medicinal plant Rehmannia glutinosa, has shown anticancer efficacy in various cancer cells. However, its effect on breast cancer remains unclear. In this study, we aim to investigate the anti-breast cancer activity of catalpol and elucidate its underlying mechanism. Cell counting kit-8 (CCK-8) and morphology change showed that catalpol could inhibit the proliferation and viability of MCF-7 cells. Catalpol administration reduced the tumor volume in xenograft model. Catalpol induced apoptosis in MCF-7 cells confirmed by Hoechst 33342 staining and Annexin V-FITC/PI double staining. In vivo, catalpol also induced apoptosis as seen from the increased level of terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) in tumor. According to JC-1 and Dichlorodi-hydrofluorescein Diacetate (DCFH-DA) staining, loss of mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) generation was found in MCF-7 cells treated with catalpol. Furthermore, catalpol also increased the level of cytoplasmic cytochrome c and activity of caspase-3 in MCF-7 cells. Likewise, histopathological and immunohistochemical (IHC) assay also found that catalpol enhanced the levels of cytochrome c and caspase-3 in breast cancer tissues. Ultimately, acetylation, 2-hydroxyisobutyrylation and lactylation were dramatically increased, whereas succinylation, malonylation and phosphorylation were markedly decreased in the breast cancer tumor treated with catalpol. Taken together, catalpol inhibited breast cancer in vitro and in vivo through induction of apoptosis via mitochondria apoptosis pathway and regulation of protein post-translational modifications (PTMs). Thus, it can be considered as an excellent candidate compound for treatment of breast cancer.

A non-metabolic function of hexokinase 2 in small cell lung cancer: promotes cancer cell stemness by increasing USP11-mediated CD133 stability

Background

Maintenance of cancer stem‐like cell (CSC) stemness supported by aberrantly regulated cancer cell metabolism is critical for CSC self‐renewal and tumor progression. As a key glycolytic enzyme, hexokinase 2 (HK2) plays an instrumental role in aerobic glycolysis and tumor progression. However, whether HK2 directly contribute to CSC stemness maintenance in small cell lung cancer (SCLC) is largely unclear. In this study, we aimed to investgate whether HK2 independent of its glycolytic activity is directly involved in stemness maintenance of CSC in SCLC.

Methods

Immunoblotting analyses were conducted to determine the expression of HK2 in SCLC CSCs and their differentiated counterparts. CSC‐like properties and tumorigenesis of SCLC cells with or without HK2 depletion or overexpression were examined by sphere formation assay and xenograft mouse model. Immunoprecipitation and mass spectrometry analyses were performed to identify the binding proteins of CD133. The expression levels of CD133‐associated and CSC‐relevant proteins were evaluated by immunoblotting, immunoprecipitation, immunofluorescence, and immunohistochemistry assay. RNA expression levels of Nanog, POU5F1, Lin28, HK2, Prominin‐1 were analyzed through quantitative reverse transcription PCR. Polyubiquitination of CD133 was examined by in vitro or in vivo ubiquitination assay. CD133⁺ cells were sorted by flow cytometry using an anti‐CD133 antibody.

Results

We demonstrated that HK2 expression was much higher in CSCs of SCLC than in their differentiated counterparts. HK2 depletion inhibited CSC stemness and promoted CSC differentiation. Mechanistically, non‐mitochondrial HK2 directly interacted with CD133 and enhanced CD133 expression without affecting CD133 mRNA levels. The interaction of HK2 and CD133 promoted the binding of the deubiquitinase ubiquitin‐specific protease 11 (USP11) to CD133, thereby inhibiting CD133 polyubiquitylation and degradation. HK2‐mediated upregulation of CD133 expression enhanced the expression of cell renewal regulators, SCLC cell stemness, and tumor growth in mice. In addition, HK2 expression was positively correlated with CD133 expression in human SCLC specimens, and their expression levels were associated with poor prognosis of SCLC patients.

Conclusions

These results revealed a critical non‐metabolic function of HK2 in promotion of cancer cell stemness. Our findings provided new insights into the multifaceted roles of HK2 in tumor development.

GCN5 participates in KLF4-VEGFA feedback to promote endometrial angiogenesis

Endometrial angiogenesis is necessary for good endometrial receptivity. Krüppel-like factor 4 (KLF4) is a transcription factor that is essential for regulating angiogenesis. Here we found that vascular endothelial growth factor A (VEGFA) can form a positive feedback loop with KLF4 to promote the proliferation and migration of human endometrial microvascular endothelial cells (HEMECs) and inhibit cell apoptosis. General control non-derepressible 5 (GCN5) is also time-dependent on VEGFA and participates in the KLF4-VEGFA loop. In addition, we found that GCN5 is a succinyltransferase that modulates the succinylation of histones and nonhistones. GCN5 interacts with KLF4 and is recruited to the KLF4-binding site of the VEGFA promoter to succinylate H3K79, which initiates gene transcription epigenetically. For nonhistones, GCN5 succinylates KLF4 that is activated by ERK signaling in HEMECs treated with VEGFA to increase its transcription activity. These results demonstrate KLF4-VEGFA positive feedback loop is regulated by epigenetics, which contributes to endometrial angiogenesis.

•

KLF4 mediates VEGFA-induced endometrial angiogenesis

•

VEGFA increases the interaction between KLF4 and GCN5

•

VEGFA promotes H3K79 succinylation by upregulating KLF4 and GCN5

•

VEGFA succinylates KLF4 and promotes interaction of KLF4 and GCN5 via ERK pathway

KAT2A affects tumor metabolic reprogramming in colon cancer progression through epigenetic activation of E2F1

Lysine acetyltransferase 2 A (KAT2A) has been implicated in tumorigenesis; nevertheless, the mechanism underlying its tumor-initiating effect remains elusive. In the present study, we aimed to identify the possible role of KAT2A in regulating metabolic reprogramming, a hallmark of cancer, in colon cancer (CC). KAT2A was found to be overexpressed in CC and correlated with metastases. KAT2A induced proliferation, migration, invasion, and epithelial-mesenchymal transition of CC cells, along with elevated cellular glycolytic capacity and mitochondrial stress. Functional enrichment analyses predicted and ChIP assays verified that KAT2A activated E2F transcription factor 1 (E2F1) by modifying the acetylation of H3K9. Rescue experiments revealed that E2F1 downregulation inhibited cellular activity, aerobic glycolysis and mitochondrial respiration in CC in the presence of KAT2A. Moreover, KAT2A/E2F1 promoted tumorigenic activity and lung metastases of CC cells in mice. Taken together, our findings demonstrate the substantial role of KAT2A in the modulation of post-translational modifications of E2F1 in CC, suggesting that knockdown of KAT2A may be a potential strategy for CC treatment.

Hypoxia-induced NFATc3 deSUMOylation enhances pancreatic carcinoma progression

The transcriptional regulator nuclear factor of activated T-cells, cytoplasmic 3 (NFATc3) is constitutively activated in several cancer types and plays important roles in cancer development and progression. Heavily phosphorylated NFATc3 resides in the cytoplasm of resting cells, and dephosphorylated NFATc3 translocates to the nucleus to activate expression of target genes in cells exposed to stimuli, for instance, hypoxia. Apart from phosphorylation, various post-translational modifications have been reported to regulate NFAT transcriptional activity. However, the mechanisms remain elusive. Here, we have demonstrated that NFATc3 is activated in human pancreatic ductal adenocarcinoma (PDAC) cells and that excessive activation of NFATc3 is correlated to advanced stages of PDAC and short survival time of PDAC patients. NFATc3 is deSUMOylated at K384 by SENP3 under hypoxia, which impairs the interaction between NFATc3 and phosphokinase GSK-3β, subsequently decreases NFATc3 phosphorylation and increases its nuclear occupancy. Knockdown of SENP3 greatly decreased hypoxia-induced NFATc3 nuclear occupancy. Our results highlight that SENP3-mediated deSUMOylation acts as an essential modulator of NFATc3, which is instrumental in PDAC tumor progression under hypoxia.

Roles of Negatively Charged Histone Lysine Acylations in Regulating Nucleosome Structure and Dynamics

The nucleosome, the basic repeating unit of chromatin, is a dynamic structure that consists of DNA and histones. Insights derived from biochemical and biophysical approaches have revealed that histones posttranslational modifications (PTMs) are key regulators of nucleosome structure and dynamics. Mounting evidence suggests that the newly identified negatively charged histone lysine acylations play significant roles in altering nucleosome and chromatin dynamics, subsequently affecting downstream DNA-templated processes including gene transcription and DNA damage repair. Here, we present an overview of the dynamic changes of nucleosome and chromatin structures in response to negatively charged histone lysine acylations, including lysine malonylation, lysine succinylation, and lysine glutarylation.

KMT5A-methylated SNIP1 promotes triple-negative breast cancer metastasis by activating YAP signaling

Smad nuclear-interacting protein 1 (SNIP1) is a transcription repressor related to the TGF-β signaling pathway and associates with c-MYC, a key regulator of cell proliferation and tumor development. Currently, the mechanism by which SNIP1 regulates tumorigenesis and cancer metastasis is unknown. Here, we identify that SNIP1 is a non-histone substrate of lysine methyltransferase KMT5A, which undergoes KMT5A-mediated mono-methylation to promote breast cancer cell growth, invasion and lung metastasis. Mechanistically, we show KMT5A-mediated K301 methylation of SNIP1 represents a sensing signal to release histone acetyltransferase KAT2A and promotes the interaction of c-MYC and KAT2A, and the recruitment of c-MYC/KAT2A complex to promoter of c-MYC targets. This event ultimately inhibits the Hippo kinase cascade to enhance triple-negative breast cancer (TNBC) metastasis by transcriptionally activating MARK4. Co-inhibition of KMT5A catalytic activity and YAP in TNBC xenograft-bearing animals attenuates breast cancer metastasis and increases survival. Collectively, this study presents an KMT5A methylation-dependent regulatory mechanism governing oncogenic function of SNIP1.

SNIP1 methylation initiates its oncogenic functions. Here, the authors show that SNIP1 is methylated by KMT5A and this leads to downstream signalling that activates the YAP pathway, resulting in tumorigenesis and metastasis.

Genetic and Molecular Characterization Revealed the Prognosis Efficiency of Histone Acetylation in Pan-Digestive Cancers

The imbalance between acetylation and deacetylation of histone proteins, important for epigenetic modifications, is closely associated with various diseases, including cancer. However, knowledge regarding the modification of histones across the different types of digestive cancers is still lacking. The purpose of this research was to analyze the role of histone acetylation and deacetylation in pan-digestive cancers. We systematically characterized the molecular alterations and clinical relevance of 13 histone acetyltransferase (HAT) and 18 histone deacetylase (HDAC) genes in five types of digestive cancers, including esophageal carcinoma, gastric cancer, hepatocellular carcinoma, pancreatic cancer, and colorectal cancer. Recurrent mutations and copy number variation (CNV) were extensively found in acetylation-associated genes across pan-digestive cancers. HDAC9 and KAT6A showed widespread copy number amplification across five pan-digestive cancers, while ESCO2, EP300, and HDAC10 had prevalent copy number deletions. Accordingly, we found that HAT and HDAC genes correlated with multiple cancer hallmark-related pathways, especially the histone modification-related pathway, PRC2 complex pathway. Furthermore, the expression pattern of HAT and HDAC genes stratified patients with clinical benefit in hepatocellular carcinoma and pancreatic cancer. These results indicated that acetylation acts as a key molecular regulation of pan-digestive tumor progression.

Glycometabolic rearrangements-aerobic glycolysis in pancreatic ductal adenocarcinoma (PDAC): roles, regulatory networks, and therapeutic potential

INTRODUCTION

Glycometabolic rearrangements (aerobic glycolysis) is a hallmark of pancreatic ductal adenocarcinoma (PDAC) and contributes to tumorigenesis and progression through numerous mechanisms. The targeting of aerobic glycolysis is recognized as a potential therapeutic strategy which offers the possibility of improving treatment outcomes for PDAC patients.

AREAS COVERED

In this review, the role of aerobic glycolysis and its regulatory networks in PDAC are discussed. The targeting of aerobic glycolysis in PDAC is examined, and its therapeutic potential is evaluated. The relevant literature published from 2001 to 2021 was searched in databases including PubMed, Scopus, and Embase.

EXPERT OPINION

Regulatory networks of aerobic glycolysis in PDAC are based on key factors such as c-Myc, hypoxia-inducible factor 1α, the mammalian target of rapamycin pathway, and non-coding RNAs. Experimental evidence suggests that modulators or inhibitors of aerobic glycolysis promote therapeutic effects in preclinical tumor models. Nevertheless, successful clinical translation of drugs that target aerobic glycolysis in PDAC is an obstacle. Moreover, it is necessary to identify the potential targets for future interventions from regulatory networks to design efficacious and safer agents.

Metabolic enzymes function as epigenetic modulators: A Trojan Horse for chromatin regulation and gene expression

Epigenetic modification is a fundamental biological process in living organisms, which has significant impact on health and behavior. Metabolism refers to a set of life-sustaining chemical reactions, including the uptake of nutrients, the subsequent conversion of nutrients into energy or building blocks for organism growth, and finally the clearance of redundant or toxic substances. It is well established that epigenetic modifications govern the metabolic profile of a cell by modulating the expression of metabolic enzymes. Strikingly, almost all the epigenetic modifications require substrates produced by cellular metabolism, and a large proportion of metabolic enzymes can transfer into nucleus to locally produce substrates for epigenetic modification, thereby providing an alternative link between metabolism, epigenetic modification and gene expression. Here, we summarize the recent literature pertinent to metabolic enzymes functioning as epigenetic modulators in the regulation of chromatin architecture and gene expression.

The GCN5: its biological functions and therapeutic potentials

General control non-depressible 5 (GCN5) or lysine acetyltransferase 2A (KAT2A) is one of the most highly studied histone acetyltransferases. It acts as both histone acetyltransferase (HAT) and lysine acetyltransferase (KAT). As an HAT it plays a pivotal role in the epigenetic landscape and chromatin modification. Besides, GCN5 regulates a wide range of biological events such as gene regulation, cellular proliferation, metabolism and inflammation. Imbalance in the GCN5 activity has been reported in many disorders such as cancer, metabolic disorders, autoimmune disorders and neurological disorders. Therefore, unravelling the role of GCN5 in different diseases progression is a prerequisite for both understanding and developing novel therapeutic agents of these diseases. In this review, we have discussed the structural features, the biological function of GCN5 and the mechanical link with the diseases associated with its imbalance. Moreover, the present GCN5 modulators and their limitations will be presented in a medicinal chemistry perspective.

A feedback circuit comprising EHD1 and 14-3-3ζ sustains β-catenin/c-Myc-mediated aerobic glycolysis and proliferation in non-small cell lung cancer

Mammalian Eps15 homology domain 1 (EHD1) participates in the development of non-small cell lung cancer (NSCLC). However, its role in mediating aerobic glycolysis remains unclear. Herein, microarray analysis revealed that EHD1 expression was significantly correlated with the glycolysis/gluconeogenesis pathway. Clinically, EHD1 expression was positively correlated with the maximum standard uptake value (SUVmax) in ¹⁸F-FDG PET/CT scans. Additionally, EHD1 knockdown inhibited aerobic glycolysis and proliferation in vitro and in vivo. Furthermore, Wnt/β-catenin signaling was identified as a critical EHD1-regulated pathway. Co-IP, native gel electrophoresis, and immunoblotting showed that EHD1 contributed to 14-3-3 dimerization via 14-3-3ζ and subsequent activation of β-catenin/c-Myc signaling. Analysis of the EHD1 regulatory region via ENCODE revealed the potential for c-Myc recruitment, leading to transcriptional activation of EHD1 and formation of an EHD1/14-3-3ζ/β-catenin/c-Myc positive feedback circuit. Notably, blocking this circuit with a Wnt/β-catenin inhibitor dramatically inhibited tumor growth in vivo. The positive correlations among EHD1, 14-3-3ζ, c-Myc, and LDHA were further confirmed in NSCLC tissues. Collectively, our study demonstrated that EHD1 activates a 14-3-3ζ/β-catenin/c-Myc regulatory circuit that synergistically promotes aerobic glycolysis and may constitute a promising therapeutic target for NSCLC.

Oncogenic Chromatin Modifier KAT2A Activates MCT1 to Drive the Glycolytic Process and Tumor Progression in Renal Cell Carcinoma

Objectives

This study aims to investigate the underlying mechanisms of KAT2A/MCT1 axis in renal cell carcinoma (RCC), providing potential therapeutic targets.

Methods

We obtained the expression data of KAT2A and MCT1 from The Cancer Genome Atlas Kidney Clear Cell Carcinoma (TCGA-KIRC) and International Cancer Genome Consortium (ICGC) databases. Differential analysis was conducted via the limma package. The CCK8 assay, soft agar assay, clone formation assay, and patients-derived organoid models were used to detect cell growth. The transwell and wound-healing assays were utilized to detect cell migration. The in vitro and in vivo assays were further conducted to assess the oncogenic roles of KAT2A. The transcriptome sequencing and chromatin immunoprecipitation (ChIP) sequencing were conducted to screen KAT2A downstream targets. The dose-effect curves were used to detect the 50% inhibiting concentration (IC50) of AZD3965. Data analysis was performed in the Graphpad Prism (Version 8.3.0) and R software (Version 3.6.1).

Results

Our study found that KAT2A was highly expressed in RCC versus normal samples. Prognostic analysis indicated that a high KAT2A was an independent biomarker and associated with poor survival outcomes. KAT2A could promote RCC proliferation and distal metastasis in vitro and in vivo. Transcriptome analysis and ChIP-seq were combined to find that KAT2A mainly regulated the glycolytic process. Validation and rescue assays revealed that MCT1 was the downstream target of KAT2A, and KAT2A depended on MCT1 to promote RCC malignant phenotypes. Lastly, MCT1 inhibitor (AZD3965) was effective to treat KAT2A-induced RCC progression.

Conclusion

Our study indicated that KAT2A was an oncogenic chromatin modifier that promotes RCC progression by inducing MCT1 expression. We proposed that MCT1 inhibitor (AZD3965) was useful for suppressing RCC.

Histone succinylation and its function on the nucleosome

Protein post‐translational modifications (PTMs) of histones are ubiquitous regulatory mechanisms involved in many biological processes, including replication, transcription, DNA damage repair and ontogenesis. Recently, many short‐chain acylation histone modifications have been identified by mass spectrometry (MS). Lysine succinylation (Ksuc or Ksucc) is a newly identified histone PTM that changes the chemical environment of histones and is similar to other acylation modifications; lysine succinylation appears to accumulate at transcriptional start sites and to correlate with gene expression. Although numerous studies are ongoing, there is a lack of reviews on the Ksuc of histones. Here, we review lysine succinylation sites on histones, including the chemical characteristics and the mechanism by which lysine succinylation influences nucleosomal structure, chromatin dynamics and several diseases and then discuss lysine succinylation regulation to identify theoretical and experimental proof of Ksuc on histones and in diseases to inspire further research into histone lysine succinylation as a target of disease treatment in the future.