KDM6B-mediated histone demethylation of LDHA promotes lung metastasis of osteosarcoma

Unraveling molecular aberrations and pioneering therapeutic strategies in osteosarcoma

Osteosarcoma, a rare primary bone cancer, presents diverse molecular aberrations that underscore its complexity. Despite the persistent endeavors by researchers, the limited amelioration in the five-year survival rate indicates that current therapeutic strategies prove inadequate in addressing the clinical necessities. Advancements in molecular profiling have facilitated an enhanced comprehension of the biology of osteosarcoma, offering a promising outlook for treatment. There is an urgent need to develop innovative approaches to address the complex challenges of osteosarcoma, ultimately contributing to enhanced patient outcomes. This review explores the nexus between osteosarcoma and cancer predisposition syndromes, intricacies in its somatic genome, and clinically actionable alterations. This review covers treatment strategies, including surgery, chemotherapy, immune checkpoint inhibitors (ICIs), and tyrosine kinase inhibitors (TKIs). Innovative treatment modalities targeting diverse pathways, including multi-target tyrosine kinases, cell cycle, PI3K/mTOR pathway, and DNA damage repair (DDR), offer promising interventions. This review also covers promising avenues, including antibody-drug conjugates (ADCs) and immunotherapy strategies, such as cytokines, adoptive cellular therapy (ACT), ICIs, and cancer vaccines. This comprehensive exploration contributes to a holistic understanding, offering guidance for clinical applications to advance the management of osteosarcoma.

LDHA-mediated M2-type macrophage polarization via tumor-derived exosomal EPHA2 promotes renal cell carcinoma progression

Lactate dehydrogenase A (LDHA) is known to promote the growth and invasion of various types of tumors, affects tumor resistance, and is associated with tumor immune escape. But how LDHA reshapes the tumor microenvironment and promotes the progression of renal cell carcinoma (RCC) remains unclear. In this study, we found that LDHA was highly expressed in clear cell RCC (ccRCC), and this high expression was associated with macrophage infiltration, while macrophages were highly infiltrated in ccRCC, affecting patient prognosis via M2-type polarization. Our in vivo and in vitro experiments demonstrated that LDHA and M2-type macrophages could enhance the proliferation, invasion, and migration abilities of ccRCC cells. Mechanistically, high expression of LDHA in ccRCC cells upregulated the expression of EPHA2 in exosomes derived from renal cancer. Exosomal EPHA2 promoted M2-type polarization of macrophages by promoting activation of the PI3K/AKT/mTOR pathway in macrophages, thereby promoting the progression of ccRCC. All these findings suggest that EPHA2 may prove to be a potential therapeutic target for advanced RCC.

HK2 and LDHA upregulation mediate hexavalent chromium-induced carcinogenesis, cancer development and prognosis through miR-218 inhibition

Hexavalent chromium [Cr(VI)] is one of the most common environmental contaminants due to its tremendous industrial applications, but its effects and mechanism remain to be investigated. Our previous studies showed that Cr(VI) exposure caused malignant transformation and tumorigenesis. This study showed that glycolytic proteins HK2 and LDHA levels were statistically significant changed in blood samples of Cr(VI)-exposed workers and in Cr-T cells compared to the control subjects and parental cells. HK2 and LDHA knockdown inhibited cell proliferation and angiogenesis, and higher HK2 and LDHA expression levels are associated with advanced stages and poor prognosis of lung cancer. We found that miR-218 levels were significantly decreased and miR-218 directly targeted HK2 and LDHA for inhibiting their expression. Overexpression of miR-218 inhibited glucose consumption and lactate production in Cr-T cells. Further study found that miR-218 inhibited tumor growth and angiogenesis by decreasing HK2 and LDHA expression in vivo. MiR-218 levels were negatively correlated with HK2 and LDHA expression levels and cancer development in human lung and other cancers. These results demonstrated that miR-218/HK2/LDHA pathway is vital for regulating Cr(VI)-induced carcinogenesis and human cancer development.

Machine-learning developed an iron, copper, and sulfur-metabolism associated signature predicts lung adenocarcinoma prognosis and therapy response

BACKGROUND

Previous studies have largely neglected the role of sulfur metabolism in LUAD, and no study has combine iron, copper, and sulfur-metabolism associated genes together to create prognostic signatures.

METHODS

This study encompasses 1564 LUAD patients, 1249 NSCLC patients, and over 10,000 patients with various cancer types from diverse cohorts. We employed the R package ConsensusClusterPlus to separate patients into different ICSM (Iron, Copper, and Sulfur-Metabolism) subtypes. Various machine-learning methods were utilized to develop the ICSMI. Enrichment analyses were conducted using ClusterProfiler and GSVA, while IOBR quantified immune cell infiltration. GISTIC2.0 and maftools were utilized for CNV and SNV data analysis. The Oncopredict package predicted drug information based on GDSC1. TIDE algorithm and cohorts GSE91061 and IMvigor210 evaluated patient response to immunotherapy. Single-cell data was processed using the Seurat package, AUCell package calculated cells geneset activity scores, and the Scissor algorithm identified ICSMI-associated cells. In vitro experiments was conducted to explore the role of ICSMRGs in LUAD.

RESULTS

Unsupervised clustering identified two distinct ICSM subtypes of LUAD, each with unique clinical characteristics. The ICSMI, comprising 10 genes, was constructed using integrated machine-learning methods. Its prognostic power was validated in 10 independent datasets, revealing that LUAD patients with higher ICSMI levels had poorer prognoses. Furthermore, ICSMI demonstrated superior predictive abilities compared to 102 previously published signatures. A nomogram incorporating ICSMI and clinical features exhibited high predictive performance. ICSMI positively correlated with patients gene mutations, and integrated analysis of bulk and single-cell transcriptome data revealed its association with TME modulators. Cells representing the high-ICSMI phenotype exhibited more malignant features. LUAD patients with high ICSMI levels exhibited sensitivity to chemotherapy and targeted therapy but displayed resistance to immunotherapy. In a comprehensive analysis across various cancers, ICSMI retained significant prognostic value and emerged as a risk factor for the majority of cancer patients.

CONCLUSIONS

ICSMI provides critical prognostic insights for LUAD patients, offering valuable insights into the tumor microenvironment and predicting treatment responsiveness.

A systematic pan-cancer analysis identifies LDHA as a novel predictor for immunological, prognostic, and immunotherapy resistance

Lactate dehydrogenase A (LDHA), a critical enzyme involved in glycolysis, is broadly involved multiple biological functions in human cancers. It is reported that LDHA can impact tumor immune surveillance and induce the transformation of tumor-associated macrophages, highlighting its unnoticed function of LDHA in immune system. However, in human cancers, the role of LDHA in prognosis and immunotherapy hasn't been investigated. In this study, we analyzed the expression pattern and prognostic value of LDHA in pan-cancer and explored its association between tumor microenvironment (TME), immune infiltration subtype, stemness scores, tumor mutation burden (TMB), and immunotherapy resistance. We found that LDHA expression is tumor heterogeneous and that its high expression is associated with poor prognosis in multiple human cancers. In addition, LDHA expression was positively correlated with the presence of mononuclear/macrophage cells, and also promoted the infiltration of a range of immune cells. Genomic alteration of LDHA was common in different types of cancer, while with prognostic value in pan-cancers. Pan-cancer analysis revealed that the significant correlations existed between LDHA expression and tumor microenvironment (including stromal cells and immune cells) as well as stemness scores (DNAss and RNAss) across cancer types. Drug sensitivity analysis also revealed that LDHA was able to predict response to chemotherapy and immunotherapy. Furthermore, it was confirmed that knockdown of LDHA reduced proliferation and migration ability of lung cancer cells. Taken together, LDHA could serve as a prognostic biomarker and a potential immunotherapy marker.

Identification and validation of a lactate metabolism-related six-gene prognostic signature in intrahepatic cholangiocarcinoma

PURPOSE

Intrahepatic cholangiocarcinoma (iCCA) is a highly malignant and fatal liver tumor with increasing incidence worldwide. Lactate metabolism has been recently reported as a crucial contributor to tumor progression and immune regulation in the tumor microenvironment. However, it remains poorly identified about the biological functions of lactate metabolism in iCCA, which hinders the development of prognostic tools and therapeutic interventions.

METHODS

The univariate Cox regression analysis and Boruta algorithm were utilized to identify key lactate metabolism-related genes (LMRGs), and a prognostic signature was constructed based on LMRG scores. Genomic variations and immune cell infiltration were evaluated in the high and low LMRG score groups. Finally, the biological functions of key LMRGs were verified with in vitro and in vivo experiments.

RESULTS

Patients in the high LMRG score group exhibit a poor prognosis compared to those in the low LMRG score group, with a high frequency of TP53 and KRAS mutations. Moreover, the infiltration and function of NK cells were compromised in the high LMRG score group, consistent with the results from two independent single-cell RNA sequencing datasets and immunohistochemistry of tissue microarrays. Experimental data revealed that lactate dehydrogenase A (LDHA) knockdown inhibited proliferation and migration in iCCA cell lines and tumor growth in immunocompetent mice.

CONCLUSION

Our study revealed the biological roles of LDHA in iCCA and developed a reliable lactate metabolism-related prognostic signature for iCCA, offering promising therapeutic targets for iCCA in the clinic.

RANK/RANKL axis promotes migration, invasion, and metastasis of osteosarcoma via activating NF-κB pathway

Osteosarcoma (OS) is one of the most prevalent primary bone tumors with a high degree of metastasis and poor prognosis. Epithelial-to-mesenchymal transition (EMT) is a cellular mechanism that contributes to the invasion and metastasis of cancer cells, and OS cells have been reported to exhibit EMT-like characteristics. Our previous studies have shown that the interaction between tumor necrosis factor superfamily member 11 (TNFRSF11A; also known as RANK) and its ligand TNFSF11 (also known as RANKL) promotes the EMT process in breast cancer cells. However, whether the interaction between RANK and RANKL enhances aggressive behavior by inducing EMT in OS cells has not yet been elucidated. In this study, we showed that the interaction between RANK and RANKL increased the migration, invasion, and metastasis of OS cells by promoting EMT. Importantly, we clarified that the RANK/RANKL axis induces EMT by activating the nuclear factor-kappa B (NF-κB) pathway. Furthermore, the NF-κB inhibitor dimethyl fumarate (DMF) suppressed migration, invasion, and EMT in OS cells. Our results suggest that the RANK/RANKL axis may serve as a potential tumor marker and promising therapeutic target for OS metastasis. Furthermore, DMF may have clinical applications in the treatment of lung metastasis in patients with OS.

Construction of molecular subtype model of osteosarcoma based on endoplasmic reticulum stress and tumor metastasis-related genes

Introduction

Osteosarcoma, the prevailing primary bone malignancy among children and adolescents, is frequently associated with treatment failure primarily due to its pronounced metastatic nature.

Methods

This study aimed to establish potential associations between hub genes and subtypes for the treatment of metastatic osteosarcoma. Differentially expressed genes were extracted from patients diagnosed with metastatic osteosarcoma and a control group of non-metastatic patients, using the publicly available gene expression profile (GSE21257). The intersection of these gene sets was determined by focusing on endoplasmic reticulum (ER) stress-related genes sourced from the GeneCards database. We conducted various analytical techniques, including functional and pathway enrichment analysis, WGCNA analysis, protein-protein interaction (PPI) network construction, and assessment of immune cell infiltration, using the intersecting genes. Through this analysis, we identified potential hub genes.

Results

Osteosarcoma subtype models were developed using molecular consensus clustering analysis, followed by an examination of the associations between each subtype and hub genes. A total of 138 potential differentially expressed genes related to endoplasmic reticulum (ER) stress were identified. These genes were further investigated using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA) pathways. Additionally, the PPI interaction network revealed 38 interaction relationships among the top ten hub genes. The findings of the analysis revealed a strong correlation between the extent of immune cell infiltration and both osteosarcoma metastasis and the expression of hub genes. Notably, the differential expression of the top ten hub genes was observed in osteosarcoma clusters 1 and 4, signifying their significant association with the disease.

Conclusion

The identification of ten key genes linked to osteosarcoma metastasis and endoplasmic reticulum stress bears potential clinical significance. Additionally, exploring the molecular subtype of osteosarcoma has the capacity to guide clinical treatment decisions, necessitating further investigations and subsequent clinical validations.

Single-cell sequencing of the retina shows that LDHA regulates pathogenesis of autoimmune uveitis

Autoimmune uveitis (AU) is a severe disorder causing poor vision and blindness. However, the cellular dynamics and pathogenic mechanisms underlying retinal injury in uveitis remain unclear. In this study, single-cell RNA sequencing of the retina and cervical draining lymph nodes in experimental autoimmune uveitis mice was conducted to identify the cellular spatiotemporal dynamics and upregulation of the glycolysis-related gene LDHA. Suppression of LDHA can rescue the imbalance of T effector (Teff) cells/T regulator (Treg) cells under inflammation via downregulation of the glycolysis-PI3K signaling circuit and inhibition of the migration of CXCR4+ Teff cells towards retinal tissue. Furthermore, LDHA and CXCR4 are upregulated in the peripheral blood mononuclear cells of Vogt-Koyanagi-Harada patients. The LDHA inhibitor suppresses CD4+ T cell proliferation in humans. Therefore, our data indicate that the autoimmune environment of uveitis regulates Teff cell accumulation in the retina via glycolysis-associated LDHA. Modulation of this target may provide a novel therapeutic strategy for treating AU.

Reprogramming of glucose metabolism: Metabolic alterations in the progression of osteosarcoma

Metabolic reprogramming is an adaptive response of tumour cells under hypoxia and low nutrition conditions. There is increasing evidence that glucose metabolism reprogramming can regulate the growth and metastasis of osteosarcoma (OS). Reprogramming in the progress of OS can bring opportunities for early diagnosis and treatment of OS. Previous research mainly focused on the glycolytic pathway of glucose metabolism, often neglecting the tricarboxylic acid cycle and pentose phosphate pathway. However, the tricarboxylic acid cycle and pentose phosphate pathway of glucose metabolism are also involved in the progression of OS and are closely related to this disease. The research on glucose metabolism in OS has not yet been summarized. In this review, we discuss the abnormal expression of key molecules related to glucose metabolism in OS and summarize the glucose metabolism related signaling pathways involved in the occurrence and development of OS. In addition, we discuss some of the targeted drugs that regulate glucose metabolism pathways, which can lead to effective strategies for targeted treatment of OS.

Lactate dehydrogenase A promotes nasopharyngeal carcinoma progression through the TAK1/NF-κB Axis

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a malignant tumor that originates in the nasopharyngeal mucosa and is common in China and Southeast Asian countries. Cancer cells reprogram glycolytic metabolism to promote their growth, survival and metastasis. Glycolysis plays an important role in NPC development, but the underlying mechanisms remain incompletely elucidated. Lactate dehydrogenase A (LDHA) is a crucial glycolytic enzyme, catalyzing the last step of glycolysis. This study aims to investigate the exact role of LDHA, which catalyzes the conversion of pyruvate into lactate, in NPC development.

METHODS AND RESULTS

The western blot and immunohistochemical (IHC) results indicated that LDHA was significantly upregulated in NPC cells and clinical samples. LDHA knockdown by shRNA significantly inhibited NPC cell proliferation and invasion. Further knockdown of LDHA dramatically weakened the tumorigenicity of NPC cells in vivo. Mechanistic studies showed that LDHA activated TGF-β-activated kinase 1 (TAK1) and subsequent nuclear factor κB (NF-κB) signaling to promote NPC cell proliferation and invasion. Exogenous lactate supplementation restored NPC cell proliferation and invasion inhibited by LDHA knockdown, and this restorative effect was reversed by NF-κB inhibitor (BAY 11-7082) or TAK1 inhibitor (5Z-7-oxozeaenol) treatment. Moreover, clinical sample analyses showed that LDHA expression was positively correlated with TAK1 Thr187 phosphorylation and poor prognosis.

CONCLUSIONS

Our results suggest that LDHA and its major metabolite lactate drive NPC progression by regulating TAK1 and its downstream NF-κB signaling, which could become a therapeutic target in NPC.

Identification and experimental validation of Stearoyl-CoA desaturase is a new drug therapeutic target for osteosarcoma

Osteosarcoma (OS) is the most common malignant bone tumor. Fatty acid reprogramming plays an essential role in OS progression. However, new fatty acid related therapeutic targets of OS have not been completely elucidated. Therefore, we firstly identified 113 differentially expressed fatty acid metabolism genes using bioinformatic analysis, 19 of which were found to be associated with OS prognosis. Then, 7 hub genes were screened out and yielded a strong prediction accuracy (AUC value = 0.88, at 3 years) for predicting the survival status of OS patients. Furthermore, we confirmed that SCD was highly expressed in OS cells and patients. And Knock-down of SCD impaired proliferation and migration of OS cells. Moreover, SCD was transcriptionally activated by c-Myc to promote proliferation and migration of OS cells. Finally, SCD inhibitor could significantly induce OS ferroptosis in vitro and in vivo. In conclusion, we identified that SCD was a reliable risk factor for OS patients. And SCD was activated by c-Myc. The inhibitor of SCD could significantly impaired OS growth and induce OS ferroptosis, which indicated that SCD was a potential drug target for OS treatment.

Elevation of H3K27me3 level contributes to the radioresistance of nasopharyngeal carcinoma by inhibiting OAS1 expression

Radiotherapy has long been a main treatment option for nasopharyngeal carcinoma (NPC). However, during clinical treatment, NPC is prone to developing radioresistance, resulting in treatment failure. This study aims to examine the role of histone methylation in the induction of radioresistance. It was found that the radioresistance of NPC cells was related to the increase of the level of histone H3 lysine 27 trimethylation (H3K27me3). Treatment of cells with histone methyltransferase inhibitor GSK126 increased the radiosensitivity of NPC cells by triggering Bcl2 apoptosis regulator/BCL2-associated X, apoptosis regulator (Bcl2/BAX) signaling pathway. Bioinformatics analysis indicated that the expression of 2'-5'-oligoadenylate synthetase 1 (OAS1) was reduced in the radioresistant cells but increased in the GSK126-treated cells. Chromatin immunoprecipitation assay confirmed that the decrease of OAS1 expression in radioresistant cells was mainly due to the enrichment of H3K27me3 in its promoter region. Furthermore, downregulation of OAS1 reduced apoptosis due to the inhibition of Bcl2/BAX pathway after irradiation, while OAS1 overexpression increased radiosensitivity. Our findings revealed for the first time that the increase of H3K27me3 level was associated with the decrease of OAS1 expression, leading to the inhibition of apoptosis and ultimately contributing to the radioresistance of NPC cells. Moreover, the histone methyltransferase inhibitor GSK126 could overcome the radioresistance and thus might be a potential therapeutic strategy for NPC.NEW & NOTEWORTHY Our findings revealed for the first time that the increase of H3K27me3 level was associated with the decrease of OAS1 expression, leading to the inhibition of apoptosis and ultimately contributing to the radioresistance of NPC cells. Moreover, we demonstrated that the histone methyltransferase inhibitor GSK126 could be a promising therapeutic strategy for NPC by overcoming radioresistance, providing valuable insights into the clinical treatment of NPC.

Glycometabolic reprogramming in cementoblasts: A vital target for enhancing cell mineralization

Cementum, a constituent part of periodontal tissues, has important adaptive and reparative functions. It serves to attach the tooth to alveolar bone and acts as a barrier delimit epithelial growth and bacteria evasion. A dynamic and highly responsive cementum is essential for maintaining occlusal relationships and the integrity of the root surface. It is a thin layer of mineralized tissue mainly produced by cementoblasts. Cementoblasts are osteoblast-like cells essential for the restoration of periodontal tissues. In recent years, glucose metabolism has been found to be critical in bone remodeling and osteoblast differentiation. However, the glucose metabolism of cementoblasts remains incompletely understood. First, immunohistochemistry staining and in vivo tracing with 18 F-fluorodeoxyglucose (18 F-FDG) revealed significantly higher glucose metabolism in cementum formation. To test the bioenergetic pathways of cementoblast differentiation, we compared the bioenergetic profiles of mineralized and unmineralized cementoblasts. As a result, we observed a significant increase in the consumption of glucose and production of lactate, coupled with the higher expression of glycolysis-related genes. However, the expression of oxidative phosphorylation-related genes was downregulated. The verified results were consistent with the RNA sequencing results. Likewise, targeted energy metabolomics shows that the levels of glycolytic metabolites were significantly higher in the mineralized cementoblasts. Seahorse assays identified an increase in glycolytic flux and reduced oxygen consumption during cementoblast mineralization. Apart from that, we also found that lactate dehydrogenase A (LDHA), a key glycolysis enzyme, positively regulates the mineralization of cementoblasts. In summary, cementoblasts mainly utilized glycolysis rather than oxidative phosphorylation during the mineralization process.

E2F1-driven histone demethylase KDM6B enhances thyroid malignancy via manipulating TFEB-dependent autophagy axis

Aberrant epigenetic modifications or events regulate autophagy to influence tumor progression, which has gained increasing attention. KDM6B is an essential histone demethylase that participates in multiple processes of tumors, but its role in thyroid carcinoma (THCA) remains to be unknown. Here, in this study, we used the MTT assay to screen and validate that KDM6B is an essential demethylase for THCA. KDM6B promotes THCA proliferation, migration, invasion in vitro and in vivo. Transcriptional factor E2F1 directly binds to the promoter region of KDM6B and regulates its mRNA levels in THCA. E2F1 partially depended on KDM6B to exert its oncogenic functions. Mechanistically, KDM6B binds to TFEB promoter region and mediates the demethylation of H3K27me3. KDM6B depended on TFEB to activate a series of lysosomal-related genes. KDM6B enhances autophagy process, as evidenced by elevated p62 and Beclin-1 proteins. KDM6B depended on TFEB-driven autophagy activity to accelerate THCA progression. Lastly, targeting autophagy with 3-MA could notably abrogate growth of KDM6Bhigh THCA, but has mild influence on KDM6Blow THCA. Together, this study identified KDM6B as an essential epigenetic regulator for THCA, functioning as an autophagy regulator. The fundamental mechanisms underlying E2F1/KDM6B/TFEB axis provided novel vulnerabilities for THCA treatment.

CDK7-YAP-LDHD axis promotes D-lactate elimination and ferroptosis defense to support cancer stem cell-like properties

Reprogrammed cellular metabolism is essential for maintaining cancer stem cells (CSCs) state. Here, we report that mitochondrial D-lactate catabolism is a necessary initiating oncogenic event during tumorigenesis of esophageal squamous cell carcinoma (ESCC). We discover that cyclin-dependent kinase 7 (CDK7) phosphorylates nuclear Yes-associated protein 1 (YAP) at S127 and S397 sites and enhances its transcription function, which promotes D-lactate dehydrogenase (LDHD) protein expression. Moreover, LDHD is enriched significantly in ESCC-CSCs rather than differentiated tumor cells and high LDHD status is connected with poor prognosis in ESCC patients. Mechanistically, the CDK7-YAP-LDHD axis helps ESCC-CSCs escape from ferroptosis induced by D-lactate and generates pyruvate to satisfy energetic demands for their elevated self-renewal potential. Hence, we conclude that esophageal CSCs adopt a D-lactate elimination and pyruvate accumulation mode dependent on CDK7-YAP-LDHD axis, which drives stemness-associated hallmarks of ESCC-CSCs. Reasonably, targeting metabolic checkpoints may serve as an effective strategy for ESCC therapy.

Epigenetic Changes Associated with Osteosarcoma: A Comprehensive Review

Osteosarcoma is the most common malignant primary bone tumor in children and adolescents. While clinical outcomes have improved, the 5-year survival rate is only around 60% if discovered early and can require debilitating treatments, such as amputations. A better understanding of the disease could lead to better clinical outcomes for patients with osteosarcoma. One promising avenue of osteosarcoma research is in the field of epigenetics. This research investigates changes in genetic expression that occur above the genome rather than in the genetic code itself. The epigenetics of osteosarcoma is an active area of research that is still not fully understood. In a narrative review, we examine recent advances in the epigenetics of osteosarcoma by reporting biomarkers of DNA methylation, histone modifications, and non-coding RNA associated with disease progression. We also show how cancer tumor epigenetic profiles are being used to predict and improve patient outcomes. The papers in this review cover a large range of epigenetic target genes and pathways that modulate many aspects of osteosarcoma, including but not limited to metastases and chemotherapy resistance. Ultimately, this review will shed light on the recent advances in the epigenetics of osteosarcoma and illustrate the clinical benefits of this field of research.

LDHA as a regulator of T cell fate and its mechanisms in disease

T cells are the main force of anti-infection and antitumor and are also involved in autoimmune diseases. During the development of these diseases, T cells need to rapidly produce large amounts of energy to satisfy their activation, proliferation, and differentiation. In this review, we introduced lactate dehydrogenase A(LDHA), predominantly involved in glycolysis, which provides energy for T cells and plays a dual role in disease by mediating lactate production, non-classical enzyme activity, and oxidative stress. Mechanistically, the signaling molecule can interact with the LDHA promoter or regulate LDHA activity through post-translational modifications. These latest findings suggest that modulation of LDHA may have considerable therapeutic effects in diseases where T-cell activation is an important pathogenesis.

Molecular mechanisms of osteosarcoma metastasis and possible treatment opportunities

In osteosarcoma patients, metastasis of the primary cancer is the leading cause of death. At present, management options to prevent metastasis are limited and non-curative. In this study, we review the current state of knowledge on the molecular mechanisms of metastasis and discuss promising new therapies to combat osteosarcoma metastasis. Genomic and epigenomic changes, metabolic reprogramming, transcription factors, dysregulation of physiologic pathways, and alterations to the tumor microenvironment are some of the changes reportedly involved in the regulation of osteosarcoma metastasis. Key factors within the tumor microenvironment include infiltrating lymphocytes, macrophages, cancer-associated fibroblasts, platelets, and extracellular components such as vesicles, proteins, and other secreted molecules. We conclude by discussing potential osteosarcoma-limiting agents and their clinical studies.

KDM6B promotes gastric carcinogenesis and metastasis via upregulation of CXCR4 expression

KDM6B (Lysine-specific demethylase 6B) is a histone lysine demethyltransferase that plays a key role in many types of cancers. However, its potential role in gastric cancer (GC) remains unclear. Here, we focused on the clinical significance and potential role of KDM6B in GC. We found that the KDM6B expression is upregulated in GC tissues and that its high expression in patients is related to poor prognosis. KDM6B ectopic expression promotes GC cells' proliferation and metastasis, while its inhibition has opposite effects in vitro and in vivo. Mechanistically, KDM6B promotes GC cells proliferation and metastasis through its enzymatic activity through the induction of H3K27me3 demethylation near the CXCR4 (C-X-C chemokine receptor type 4) promoter region, resulting in the upregulation of CXCR4 expression. Furthermore, H. pylori was found to induce KDM6B expression. In conclusion, our results suggest that KDM6B is aberrantly expressed in GC and plays a key role in gastric carcinogenesis and metastasis through CXCR4 upregulation. Our work also suggests that KDM6B may be a potential oncogenic factor and a therapeutic target for GC.

A Screening of Epigenetic Therapeutic Targets for Non-Small Cell Lung Cancer Reveals PADI4 and KDM6B as Promising Candidates

Despite advances in diagnostic and therapeutic approaches for lung cancer, new therapies targeting metastasis by the specific regulation of cancer genes are needed. In this study, we screened a small library of epigenetic inhibitors in non-small-cell lung cancer (NSCLC) cell lines and evaluated 38 epigenetic targets for their potential role in metastatic NSCLC. The potential candidates were ranked by a streamlined approach using in silico and in vitro experiments based on publicly available databases and evaluated by real-time qPCR target gene expression, cell viability and invasion assays, and transcriptomic analysis. The survival rate of patients with lung adenocarcinoma is inversely correlated with the gene expression of eight epigenetic targets, and a systematic review of the literature confirmed that four of them have already been identified as targets for the treatment of NSCLC. Using nontoxic doses of the remaining inhibitors, KDM6B and PADI4 were identified as potential targets affecting the invasion and migration of metastatic lung cancer cell lines. Transcriptomic analysis of KDM6B and PADI4 treated cells showed altered expression of important genes related to the metastatic process. In conclusion, we showed that KDM6B and PADI4 are promising targets for inhibiting the metastasis of lung adenocarcinoma cancer cells.

Lysosome-targeted cyclometalated iridium(III) complexes: JMJD inhibition, dual induction of apoptosis and autophagy

A series of cyclometalated iridium(III) complexes with the formula [Ir(C^N)2 L](PF6) (C^N = 2-phenylpyridine (ppy, in Ir-1), 2-(2-thienyl)pyridine (thpy, in Ir-2), 2-(2,4-difluorophenyl)pyridine (dfppy, in Ir-3), L = 2-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)quinolin-8-ol) were designed and synthesized, which utilize 8-hydroxyquinoline derivative as N^N ligands to chelate the cofactor Fe2+ of the Jumonji domain-containing protein (JMJD) histone demethylase. As expected, the results of UV/Vis titration analysis confirm the chelating capabilities of Ir-1-3 for Fe2+, and molecular docking studies also show that Ir-1-3 can interact with the active pocket of JMJD protein, and treatment of cells with Ir-1-3 results in significant upregulation of trimethylated histone 3 lysine 9 (H3K9Me3), indicating the inhibition of JMJD activity. Meanwhile, Ir-1-3 exhibit much higher cytotoxicity against the tested tumor cell lines compared with the clinical chemotherapeutic agent cisplatin. And Ir-1-3 can block the cell cycle at G2/M phase and inhibit cell migration and colony formation. Further studies show that Ir-1-3 can specifically accumulate in lysosomes, damage the integrity of lysosomes, and induce apoptosis and autophagy. Reduction of mitochondrial membrane potential (MMP) and elevation of reactive oxygen species (ROS) also contribute to the antitumor effects of Ir-1-3. Finally, Ir-1 can inhibit tumor growth effectively in vivo and increase the expression of H3K9Me3 in tumor tissues. Our study demonstrates that these iridium(III) complexes are promising anticancer agents with multiple functions, including the inhibition of JMJD and induction of apoptosis and autophagy.

The roles of glycolysis in osteosarcoma

Metabolic reprogramming is of great significance in the progression of various cancers and is critical for cancer progression, diagnosis, and treatment. Cellular metabolic pathways mainly include glycolysis, fat metabolism, glutamine decomposition, and oxidative phosphorylation. In cancer cells, reprogramming metabolic pathways is used to meet the massive energy requirement for tumorigenesis and development. Metabolisms are also altered in malignant osteosarcoma (OS) cells. Among reprogrammed metabolisms, alterations in aerobic glycolysis are key to the massive biosynthesis and energy demands of OS cells to sustain their growth and metastasis. Numerous studies have demonstrated that compared to normal cells, glycolysis in OS cells under aerobic conditions is substantially enhanced to promote malignant behaviors such as proliferation, invasion, metastasis, and drug resistance of OS. Glycolysis in OS is closely related to various oncogenes and tumor suppressor genes, and numerous signaling pathways have been reported to be involved in the regulation of glycolysis. In recent years, a vast number of inhibitors and natural products have been discovered to inhibit OS progression by targeting glycolysis-related proteins. These potential inhibitors and natural products may be ideal candidates for the treatment of osteosarcoma following hundreds of preclinical and clinical trials. In this article, we explore key pathways, glycolysis enzymes, non-coding RNAs, inhibitors, and natural products regulating aerobic glycolysis in OS cells to gain a deeper understanding of the relationship between glycolysis and the progression of OS and discover novel therapeutic approaches targeting glycolytic metabolism in OS.

Histone demethylase JMJD3 downregulation protects against aberrant force-induced osteoarthritis through epigenetic control of NR4A1

Osteoarthritis (OA) is a prevalent joint disease with no effective treatment strategies. Aberrant mechanical stimuli was demonstrated to be an essential factor for OA pathogenesis. Although multiple studies have detected potential regulatory mechanisms underlying OA and have concentrated on developing novel treatment strategies, the epigenetic control of OA remains unclear. Histone demethylase JMJD3 has been reported to mediate multiple physiological and pathological processes, including cell differentiation, proliferation, autophagy, and apoptosis. However, the regulation of JMJD3 in aberrant force-related OA and its mediatory effect on disease progression are still unknown. In this work, we confirmed the upregulation of JMJD3 in aberrant force-induced cartilage injury in vitro and in vivo. Functionally, inhibition of JMJD3 by its inhibitor, GSK-J4, or downregulation of JMJD3 by adenovirus infection of sh-JMJD3 could alleviate the aberrant force-induced chondrocyte injury. Mechanistic investigation illustrated that aberrant force induces JMJD3 expression and then demethylates H3K27me3 at the NR4A1 promoter to promote its expression. Further experiments indicated that NR4A1 can regulate chondrocyte apoptosis, cartilage degeneration, extracellular matrix degradation, and inflammatory responses. In vivo, anterior cruciate ligament transection (ACLT) was performed to construct an OA model, and the therapeutic effect of GSK-J4 was validated. More importantly, we adopted a peptide-siRNA nanoplatform to deliver si-JMJD3 into articular cartilage, and the severity of joint degeneration was remarkably mitigated. Taken together, our findings demonstrated that JMJD3 is flow-responsive and epigenetically regulates OA progression. Our work provides evidences for JMJD3 inhibition as an innovative epigenetic therapy approach for joint diseases by utilizing p5RHH-siRNA nanocomplexes.

A Pan-Cancer Analysis Revealing the Dual Roles of Lysine (K)-Specific Demethylase 6B in Tumorigenesis and Immunity

Introduction: Epigenetic-targeted therapy has been increasingly applied in the treatment of cancers. Lysine (K)-specific demethylase 6B (KDM6B) is an epigenetic enzyme involved in the coordinated control between cellular intrinsic regulators and the tissue microenvironment whereas the pan-cancer analysis of KDM6B remains unavailable.

Methods: The dual role of KDM6B in 33 cancers was investigated based on the GEO (Gene Expression Omnibus) and TCGA (The Cancer Genome Atlas) databases. TIMER2 and GEPIA2 were applied to investigate the KDM6B levels in different subtypes or stages of tumors. Besides, the Human Protein Atlas database allowed us to conduct a pan-cancer study of the KDM6B protein levels. GEPIA2 and Kaplan–Meier plotter were used for the prognosis analysis in different cancers. Characterization of genetic modifications of the KDM6B gene was analyzed by the cBioPortal. DNA methylation levels of different KDM6B probes in different TCGA tumors were analyzed by MEXPRESS. TIMER2 was applied to determine the association of the KDM6B expression and immune infiltration and DNA methyltransferases. Spearman correlation analysis was used to assess the association of the KDM6B expression with TMB (tumor mutation burden) and MSI (microsatellite instability). The KEGG (Kyoto encyclopedia of genes and genomes) pathway analysis and GO (Gene ontology) enrichment analysis were used to further investigate the potential mechanism of KDM6B in tumor pathophysiology.

Results: KDM6B was downregulated in 11 cancer types and upregulated across five types. In KIRC (kidney renal clear cell carcinoma) and OV (ovarian serous cystadenocarcinoma), the KDM6B level was significantly associated with the pathological stage. A high level of KDM6B was related to poor OS (overall survival) outcomes for THCA (thyroid carcinoma), while a low level was correlated with poor OS and DFS (disease-free survival) prognosis of KIRC. The KDM6B expression level was associated with TMB, MSI, and immune cell infiltration, particularly cancer-associated fibroblasts, across various cancer types with different correlations. Furthermore, the enrichment analysis revealed the relationship between H3K4 and H3K27 methylation and KDM6B function.

Conclusion: Dysregulation of the DNA methyltransferase activity and methylation levels of H3K4 and H3K27 may involve in the dual role of KDM6B in tumorigenesis and development. Our study offered a relatively comprehensive understanding of KDM6B’s dual role in cancer development and response to immunotherapy.

Noncoding RNAs in the Glycolysis of Ovarian Cancer

Energy metabolism reprogramming is the characteristic feature of tumors. The tumorigenesis, metastasis, and drug resistance of ovarian cancer (OC) is dependent on energy metabolism. Even under adequate oxygen conditions, OC cells tend to convert glucose to lactate, and glycolysis can rapidly produce ATP to meet their metabolic energy needs. Non-coding RNAs (ncRNAs) interact directly with DNA, RNA, and proteins to function as an essential regulatory in gene expression and tumor pathology. Studies have shown that ncRNAs regulate the process of glycolysis by interacting with the predominant glycolysis enzyme and cellular signaling pathway, participating in tumorigenesis and progression. This review summarizes the mechanism of ncRNAs regulation in glycolysis in OC and investigates potential therapeutic targets.

Positive Feedback Regulation of Circular RNA Hsa_circ_0000566 and HIF-1α promotes Osteosarcoma Progression and Glycolysis Metabolism

Hypoxia is an indispensable factor for cancer progression and is closely associated with the Warburg effect. Circular RNAs (CircRNA) have garnered considerable attention in molecular malignancy therapy as they are potentially important modulators. However, the roles of circRNAs and hypoxia in osteosarcoma (OS) progression have not yet been elucidated. This study reveals the hypoxia-sensitive circRNA, Hsa_circ_0000566, that plays a crucial role in OS progression and energy metabolism under hypoxic stress. Hsa_circ_0000566 is regulated by hypoxia-inducible factor-1α (HIF-1α) and directly binds to it as well as to the Von Hippel-Lindau (VHL) E3 ubiquitin ligase protein. Consequentially, binding between VHL and HIF-1α is impeded. Furthermore, Hsa_circ_0000566 contributes to OS progression by binding to HIF-1α (while competing with VHL) and by confers protection against HIF-1α against VHL-mediated ubiquitin degradation. These findings demonstrate the existence of a positive feedback loop formed by HIF-1α and Hsa_circ_0000566 and the key role they play in OS glycolysis. Taken together, these data indicate the significance of Hsa_circ_0000566 in the Warburg effect and suggest that Hsa_circ_0000566 could be a potential therapeutic target to combat OS progression.

KDM6 Demethylases and Their Roles in Human Cancers

Cancer therapy is moving beyond traditional chemotherapy to include epigenetic approaches. KDM6 demethylases are dynamic regulation of gene expression by histone demethylation in response to diverse stimuli, and thus their dysregulation has been observed in various cancers. In this review, we first briefly introduce structural features of KDM6 subfamily, and then discuss the regulation of KDM6, which involves the coordinated control between cellular metabolism (intrinsic regulators) and tumor microenvironment (extrinsic stimuli). We further describe the aberrant functions of KDM6 in human cancers, acting as either a tumor suppressor or an oncoprotein in a context-dependent manner. Finally, we propose potential therapy of KDM6 enzymes based on their structural features, epigenetics, and immunomodulatory mechanisms, providing novel insights for prevention and treatment of cancers.

Osteosarcoma mechanobiology and therapeutic targets

Osteosarcoma (OS) is the one of the most common primary tumors of bone with less than a 20% 5-year survival rate after the development of metastases. OS is highly predisposed in Paget's disease (PD) of bone, and both have common characteristic skeletal features due to rapid bone remodeling. OS prognosis is location dependent which further emphasizes the likely contribution of the bone microenvironment in its pathogenesis. Mechanobiology is the phenomenon when mechanical cues from the changing physical microenvironment of bone are transduced to biological pathways through mechanosensitive cellular components. Mechanobiology-driven therapies have been used for curbing tumor progression by direct alteration of the physical microenvironment or inhibition of metastasis-associated mechanosensitive proteins. This review emphasizes the contribution of mechanobiology to OS progression, and sheds light on current mechanobiology-based therapies and potential new targets for improving disease management. Additionally, the variety of 3D models currently used to study OS mechanobiology are summarized.