PDHX acetylation facilitates tumor progression by disrupting PDC assembly and activating lactylation-mediated gene expression

Lactylation as a metabolic epigenetic modification: Mechanistic insights and regulatory pathways from cells to organs and diseases

In recent years, lactylation, a novel post-translational modification, has demonstrated a unique role in bridging cellular metabolism and epigenetic regulation. This modification exerts a dual-edged effect in both cancer and non-cancer diseases by dynamically integrating the supply of metabolic substrates and the activity of modifying enzymes: on one hand, it promotes tissue homeostasis and repair through the activation of repair genes; on the other, it exacerbates pathological progression by driving malignant phenotypes. In the field of oncology, lactylation regulates key processes such as metabolic reprogramming, immune evasion, and therapeutic resistance, thereby shaping the heterogeneity of the tumor microenvironment. In non-cancerous diseases, including neurodegeneration and cardiovascular disorders, its aberrant activation can lead to mitochondrial dysfunction, fibrosis, and chronic inflammation. Existing studies have revealed a dynamic regulatory network formed by the cooperation of modifying and demodifying enzymes, and have identified mechanisms such as subcellular localization and RNA metabolism intervention that influence disease progression. Nevertheless, several challenges remain in the field. This article comprehensively summarizes the disease-specific regulatory mechanisms of lactylation, with the aim of providing a theoretical foundation for its targeted therapeutic application.

Epigenetic modification and tumor immunity: Unraveling the interplay with the tumor microenvironment and its therapeutic vulnerability and implications

In the ever-evolving arena of molecular biology, epigenetic modifications stand out as crucial determinants in the orchestration of cellular identity, function, and fate. This review analyzes the close relationship between epigenetics and tumor immunity, emphasizing the intricate interplay with the tumor microenvironment (TME). Rooted in the knowledge that the incidence of cancer correlates strongly with the biological and genetic age, we highlight DNA methylation as a cornerstone of the "epigenetic aging" process with close ties to tumorigenesis. The TME, with its diverse cellular and acellular constituents, is an active participant in tumor biology, further complicated by epigenetic alterations. These modifications, from DNA methylation to histone changes, not only shape the TME but are reciprocally influenced by it, reinforcing a cycle that propels malignancy. Through this exploration, we underline the importance of understanding this mutual relationship, as it holds significant implications for tumor growth, heterogeneity, and therapeutic resistance. Ultimately, this review illuminates the potential of harnessing epigenetic insights for innovative cancer therapeutic strategies, pointing towards a promising avenue for future cancer management.

Lactylation in cancer progression and drug resistance

Lactate plays a crucial role as an energy substrate, metabolite, and signaling molecule in cancer. Lactate has long been considered a byproduct of glycolysis. Still, the lactate shuttle hypothesis has changed the lactate paradigm, revealing the implications of lactate in cellular metabolism and cellular communications that can transcend the compartment barrier and occur within and between different cells, tissues, and organs. Due to the Warburg effect, the tumor produces a large amount of lactate, thus creating a low-nutrition, hypoxic, and low-pH tumor microenvironment (TME). Consequently, immunosuppressive networks are built to acquire immune evasion potential and regulate tumor growth. Lactylation is a newly discovered post-translational modification of lysine residues with the capacity for transcriptional regulation via histone modification and modulation of non-histone protein functions, which links gene regulation to cellular metabolism by aberrant metabolism activity and epigenetic modification. There is growing evidence that lactylation plays a crucial role in cancer progression and drug resistance. Targeting lactylation enzymes or metabolic pathways has shown promising effects in suppressing cancer progression and drug resistance, highlighting the therapeutic potential of this modification. Therefore, in this review, we offer a systematic overview of lactate homeostasis in physiological and pathological processes as well as discuss the influence of lactylation in cancer progression and drug resistance and underlying molecular mechanisms, providing a theoretical basis for further research.

PRMT3 drives PD-L1-mediated immune escape through activating PDHK1-regulated glycolysis in hepatocellular carcinoma

Aberrant expression of programmed death ligand-1 (PD-L1) facilitates tumor immune evasion. Protein arginine methyltransferase 3 (PRMT3), a member of type I PRMT family, mediates asymmetric dimethylarginine (ADMA) modification of various substrate proteins. This study investigates the role of PRMT3 in PD-L1-associated tumor immunosuppression in hepatocellular carcinoma (HCC). Hepatocyte-specific knockout of Prmt3 significantly suppressed HCC progression in DEN-CCL4-treated mice. Knockout of Prmt3 in HCC cells markedly increased CD8+ T cell infiltration, and reduced lactate production in tumors. PRMT3 interacted with pyruvate dehydrogenase kinase 1 (PDHK1), asymmetric dimethylation of PDHK1 at arginine 363 and 368 residues and increased its kinase activity. The R363/368 K mutant or inhibition of PDHK1 by JX06 blocked the effect of PRMT3 on lactate production. JX06 treatment also attenuated the tumor-promoting role of PRMT3 in HCC in vitro and in vivo. Furthermore, RNA-seq analysis revealed that knockout of PRMT3 downregulates the tumor-associated immune checkpoint, PD-L1, in tumor tissues. Chromatin immunoprecipitation (ChIP) assay demonstrated that PRMT3 promotes lactate-induced PD-L1 expression by enhancing the direct binding of histone H3 lysine 18 lactylation (H3K18la) to the PD-L1 promoter. Tissue microarray analysis showed a positive correlation between PRMT3 and PD-L1 expression in HCC patients. Anti-PD-L1 treatment reversed PRMT3-induced tumor growth and restored CD8+ T cell infiltration. Our research links PRMT3-mediated metabolic reprogramming and immune evasion, revealing that the PRMT3-PDHK1-lactate-PD-L1 axis may be a potential target for improving the efficacy of immunotherapy in HCC.

DLAT activates EMT to promote HCC metastasis by regulating GLUT1-mediated aerobic glycolysis

BACKGROUND

Metabolic reprogramming is a hallmark of hepatocellular carcinoma (HCC) progression, driving aberrant cellular processes in response to pathological stimuli. While dihydrolipoyl transacetylase (DLAT) has been implicated in the development of various cancers, its specific role and underlying mechanisms in HCC remain unclear. This study aimed to investigate the expression, function, and mechanistic impact of DLAT in HCC.

METHODS

A comprehensive analysis was conducted using RNA sequencing data, tissue microarrays, in vitro and in vivo functional assays, and mechanistic studies to evaluate DLAT expression, its functional role in tumor progression, and associated molecular pathways in HCC.

RESULTS

Our study revealed a significant upregulation of DLAT expression in HCC, which was linked to a poor prognosis. Furthermore, we discovered that DLAT facilitated tumor metastasis by driving metabolic reprogramming in HCC cells. Mechanistically, DLAT was found to enhance glucose transporter 1 (GLUT1) expression via H3K18 acetylation, thereby promoting aerobic glycolysis and epithelial-to-mesenchymal transition (EMT), which subsequently augmented metastasis of HCC both in vitro and in vivo. Finally, we confirmed a positive correlation between DLAT and GLUT1 expression in HCC tissues.

CONCLUSIONS

These findings establish DLAT as a key regulator in HCC progression and suggest its potential as a promising predictive biomarker and therapeutic target for improving HCC diagnosis and treatment.

Lactylation modification in cardio-cerebral diseases: A state-of-the-art review

Cardio-cerebral diseases (CCDs), encompassing conditions such as coronary heart disease, myocardial infarction, stroke, Alzheimer's disease, et al., represent a significant threat to human health and well-being. These diseases are often characterized by metabolic abnormalities and remodeling in the process of pathology. Glycolysis and hypoxia-induced lactate accumulation play critical roles in cellular energy dynamics and metabolic imbalances in CCDs. Lactylation, a post-translational modification driven by excessive lactate accumulation, occurs in both histone and non-histone proteins. It has been implicated in regulating protein function across various pathological processes in CCDs, including inflammation, angiogenesis, lipid metabolism dysregulation, and fibrosis. Targeting key proteins involved in lactylation, as well as the enzymes regulating this modification, holds promise as a therapeutic strategy to modulate disease progression by addressing these pathological mechanisms. This review provides a holistic picture of the types of lactylation and the associated modifying enzymes, highlights the roles of lactylation in different pathological processes, and synthesizes the latest clinical evidence and preclinical studies in a comprehensive view. We aim to emphasize the potential of lactylation as an innovative therapeutic target for preventing and treating CCD-related conditions.

Exploring prognosis and therapeutic strategies for HBV-HCC patients based on disulfidptosis-related genes

Background

Hepatocellular carcinoma (HCC) accounts for over 80% of primary liver cancers and is the third leading cause of cancer-related deaths worldwide. Hepatitis B virus (HBV) infection is the primary etiological factor. Disulfidptosis is a newly discovered form of regulated cell death. This study aims to develop a novel HBV-HCC prognostic signature related to disulfidptosis and explore potential therapeutic approaches through risk stratification based on disulfidptosis.

Methods

Transcriptomic data from HBV-HCC patients were analyzed to identify BHDRGs. A prognostic model was established and validated using machine learning, with internal datasets and external datasets for verification. We then performed immune cell infiltration analysis, tumor microenvironment (TME) analysis, and immunotherapy-related analysis based on the prognostic signature. Besides, RT-qPCR and immunohistochemistry were conducted.

Results

A prognostic model was constructed using five genes (DLAT, STC2, POF1B, S100A9, and CPS1). A corresponding prognostic nomogram was developed based on riskScores, age, stage. Stratification by median risk score revealed a significant correlation between the prognostic signature and TME, tumor immune cell infiltration, immunotherapy efficacy, and drug sensitivity. The results of the experiments indicate that DLAT expression is higher in tumor tissues compared to adjacent tissues. DLAT expression is higher in HBV-HCC tumor tissues compared to normal tissues.

Conclusion

This study stratifies HBV-HCC patients into distinct subgroups based on BHDRGs, establishing a prognostic model with significant implications for prognosis assessment, TME remodeling, and personalized therapy in HBV-HCC patients.