Paradoxical regulation of hypoxia inducible factor-1α (HIF-1α) by histone deacetylase inhibitor in diffuse large B-cell lymphoma

The lactate metabolism and protein lactylation in epilepsy

Protein lactylation is a new form of post-translational modification that has recently been proposed. Lactoyl groups, derived mainly from the glycolytic product lactate, have been linked to protein lactylation in brain tissue, which has been shown to correlate with increased neuronal excitability. Ischemic stroke may promote neuronal glycolysis, leading to lactate accumulation in brain tissue. This accumulation of lactate accumulation may heighten neuronal excitability by upregulating protein lactylation levels, potentially triggering post-stroke epilepsy. Although current clinical treatments for seizures have advanced significantly, approximately 30% of patients with epilepsy remain unresponsive to medication, and the prevalence of epilepsy continues to rise. This study explores the mechanisms of epilepsy-associated neuronal death mediated by lactate metabolism and protein lactylation. This study also examines the potential for histone deacetylase inhibitors to alleviate seizures by modifying lactylation levels, thereby offering fresh perspectives for future research into the pathogenesis and clinical treatment of epilepsy.

[Expression and significance of jumonji domain-containing protein 2B and hypoxia inducible factor-1α in non-Hodgkin lymphoma tissues in children]

OBJECTIVES

To investigate the expression and significance of jumonji domain-containing protein 2B (JMJD2B) and hypoxia-inducible factor-1α (HIF-1α) in non-Hodgkin's lymphoma (NHL) tissues in children.

METHODS

Immunohistochemistry was used to detect the expression of JMJD2B and HIF-1α in lymph node tissue specimens from 46 children with NHL (observation group) and 24 children with reactive hyperplasia (control group). The relationship between JMJD2B and HIF-1α expression with clinicopathological characteristics and prognosis in children with NHL, as well as the correlation between JMJD2B and HIF-1α expression in NHL tissues, were analyzed.

RESULTS

The positive expression rates of JMJD2B (87% vs 21%) and HIF-1α (83% vs 42%) in the observation group were higher than those in the control group (P<0.05). The expression of JMJD2B and HIF-1α was correlated with serum lactate dehydrogenase levels and the risk of international prognostic index in children with NHL (P<0.05). The expression of JMJD2B was positively correlated with the HIF-1α expression in children with NHL (rs=0.333, P=0.024).

CONCLUSIONS

JMJD2B and HIF-1α are upregulated in children with NHL, and they may play a synergistic role in the development of pediatric NHL. JMJD2B can serve as a novel indicator for auxiliary diagnosis, evaluation of the severity, treatment guidance, and prognosis assessment in pediatric NHL.

Metabolic Reprogramming and Potential Therapeutic Targets in Lymphoma

Lymphoma is a heterogeneous group of diseases that often require their metabolism program to fulfill the demand of cell proliferation. Features of metabolism in lymphoma cells include high glucose uptake, deregulated expression of enzymes related to glycolysis, dual capacity for glycolytic and oxidative metabolism, elevated glutamine metabolism, and fatty acid synthesis. These aberrant metabolic changes lead to tumorigenesis, disease progression, and resistance to lymphoma chemotherapy. This metabolic reprogramming, including glucose, nucleic acid, fatty acid, and amino acid metabolism, is a dynamic process caused not only by genetic and epigenetic changes, but also by changes in the microenvironment affected by viral infections. Notably, some critical metabolic enzymes and metabolites may play vital roles in lymphomagenesis and progression. Recent studies have uncovered that metabolic pathways might have clinical impacts on the diagnosis, characterization, and treatment of lymphoma subtypes. However, determining the clinical relevance of biomarkers and therapeutic targets related to lymphoma metabolism is still challenging. In this review, we systematically summarize current studies on metabolism reprogramming in lymphoma, and we mainly focus on disorders of glucose, amino acids, and lipid metabolisms, as well as dysregulation of molecules in metabolic pathways, oncometabolites, and potential metabolic biomarkers. We then discuss strategies directly or indirectly for those potential therapeutic targets. Finally, we prospect the future directions of lymphoma treatment on metabolic reprogramming.

mTOR: A Potential New Target in Nonalcoholic Fatty Liver Disease

The global prevalence of nonalcoholic fatty liver disease (NAFLD) continues to rise, yet effective treatments are lacking due to the complex pathogenesis of this disease. Although recent research has provided evidence for the “multiple strikes” theory, the classic “two strikes” theory has not been overturned. Therefore, there is a crucial need to identify multiple targets in NAFLD pathogenesis for the development of diagnostic markers and targeted therapeutics. Since its discovery, the mechanistic target of rapamycin (mTOR) has been recognized as the central node of a network that regulates cell growth and development and is closely related to liver lipid metabolism and other processes. This paper will explore the mechanisms by which mTOR regulates lipid metabolism (SREBPs), insulin resistance (Foxo1, Lipin1), oxidative stress (PIG3, p53, JNK), intestinal microbiota (TLRs), autophagy, inflammation, genetic polymorphisms, and epigenetics in NAFLD. The specific influence of mTOR on NAFLD was hypothesized to be divided into micro regulation (the mechanism of mTOR’s influence on NAFLD factors) and macro mediation (the relationship between various influencing factors) to summarize the influence of mTOR on the developmental process of NAFLD, and prove the importance of mTOR as an influencing factor of NAFLD regarding multiple aspects. The effects of crosstalk between mTOR and its upstream regulators, Notch, Hedgehog, and Hippo, on the occurrence and development of NAFLD-associated hepatocellular carcinoma are also summarized. This analysis will hopefully support the development of diagnostic markers and new therapeutic targets in NAFLD.

Role of the bone marrow microenvironment in drug resistance of hematological malignances

The unique features of the tumor microenvironment (TME) govern the biological properties of many cancers, including hematological malignancies. TME factors can trigger invasion, and protect against drug cytotoxicity by inhibiting apoptosis and activating specific signaling pathways (e.g. NF-ΚB). TME remodeling is facilitated due to the high self-renewal ability of the bone marrow. Progressing tumor cells can alter some extracellular matrix (ECM) components which act as a barrier to drug penetration in the TME. The initial progression of the cell cycle is controlled by the MAPK pathway (Raf/MEK/ERK) and Hippo pathway, while the final phase is regulated by the PI3K/Akt /mTOR and WNT pathways. In this review we summarize the main signaling pathways involved in drug resistance (DR) and some mechanisms by which DR can occur in the bone marrow. The relationship between autophagy, endoplasmic reticulum stress, and cellular signaling pathways in DR and apoptosis are covered in relation to the TME.

Targeting Autophagy-Related Epigenetic Regulators for Cancer Drug Discovery

Existing evidence has demonstrated that epigenetic modifications (including DNA methylation, histone modifications, and microRNAs), which are associated with the occurrence and development of tumors, can directly or indirectly regulate autophagy. In particular, nuclear events induced by several epigenetic regulators can regulate the autophagic process and expression levels of tumor-associated genes, thereby promoting tumor progression. Tumor-associated microRNAs, including oncogenic and tumor-suppressive microRNAs, are of great significance to autophagy during tumor progression. Targeting autophagy with emerging epigenetic drugs is expected to be a promising therapeutic strategy for human tumors. From this perspective, we aim to summarize the role of epigenetic modification in the autophagic process and the underlying molecular mechanisms of tumorigenesis. Furthermore, the regulatory efficacy of epigenetic drugs on the autophagic process in tumors is also summarized. This perspective may provide a theoretical basis for the combined treatment of epigenetic drugs/autophagy mediators in tumors.

Ferroptosis-Related Gene Signature: A New Method for Personalized Risk Assessment in Patients with Diffuse Large B-Cell Lymphoma

Purpose

Diffuse large B-cell lymphoma (DLBCL) is a genetically heterogeneous disease, which makes prognostic prediction challenging. The rapid development of research on ferroptosis provides the possibility of its use in prognosis in cancer patients. The aim of the current investigation was to perform a systematic study of ferroptosis and DLBCL prognosis to identify prognostic biomarkers in DLBCL.

Materials and Methods

A total of 884 DLBCL patients from the Gene Expression Omnibus database were included in this study and were divided into a training set and a validation set. Univariate Cox regression analysis was used to investigate relationships between gene expression and prognostic values. Ferroptosis-related genes associated with overall survival in the training set were then extracted, and the least absolute shrinkage and selection operator Cox regression model was used to establish an eight-gene signature, comprising ZEB1, PSAT1, NGB, NFE2L2, LAMP2, HIF1A, FH, and CXCL2.

Results

The signature exhibited significant independent prognostic value in both the training set and the validation set. It also exhibited strong prognostic value in subgroup analysis. A nomogram integrating the eight-gene signature and components of the International Prognostic Index facilitated reliable prognostic prediction.

Conclusion

A novel and reliable ferroptosis-related gene signature that can effectively classify DLBCL patients into high-risk and low-risk groups in terms of survival rate was developed. It could be used for prognostic prediction in DLBCL patients. Targeting ferroptosis may be a therapeutic alternative in DLBCL.

Histone Deacetylases (HDACs): Evolution, Specificity, Role in Transcriptional Complexes, and Pharmacological Actionability

Histone deacetylases (HDACs) are evolutionary conserved enzymes which operate by removing acetyl groups from histones and other protein regulatory factors, with functional consequences on chromatin remodeling and gene expression profiles. We provide here a review on the recent knowledge accrued on the zinc-dependent HDAC protein family across different species, tissues, and human pathologies, specifically focusing on the role of HDAC inhibitors as anti-cancer agents. We will investigate the chemical specificity of different HDACs and discuss their role in the human interactome as members of chromatin-binding and regulatory complexes.

Integrating transcriptome-wide association study and copy number variation study identifies candidate genes and pathways for diffuse non-Hodgkin's lymphoma

BACKGROUND

The genetic basis of diffuse non-Hodgkin's lymphoma (DNHL) is largely unknown now. We conducted a large-scale transcriptome-wide association study (TWAS) of DNHL to identify novel candidates for DNHL.

METHODS

The GWAS summary data of DNHL was obtained from the UKBiobank, involving 685 cases and 451,579 controls. TWAS of DNHL was performed using tissue-specific gene expression weights generated from the Genotype-Tissue Expression (GTEx) data. The DNHLTWAS results were further validated by a previous published copy number alterations (CNA) study of DNHL. Gene ontology (GO) and pathway enrichment analysis of identified candidate genes were conducted by the DAVID 6.8.

RESULTS

We identified 214 genes with TWAS P value < 0.05 for DNHL, such as MRPL19 (P_TWAS = 0.0010), CRCP (P_TWAS = 0.0010) and SEMA3C (P_TWAS = 0.0010). After further comparing the 214 genes with copy number variations of DNHL patients, we found 1 overlapped gene, BCL10 (P_TWAS = 0.0100). We also detected 6 common GO terms shared between gene set enrichment analysis results of TWAS and CNAs, such as cytosol (P_TWAS = 0.0003, PCNAs = 4.99 × 10^-7) and membrane (P_TWAS = 0.0048, P_CNAs = 0.0046). The pathway enrichment analysis of TWAS and CNAs detected 3 common pathways, including HIF-1 signaling pathway (P_TWAS = 0.0195, P_CNAs = 1.96 × 10^-5), mTOR signaling pathway (P_TWAS = 0.0242, P_CNAs = 6.75 × 10^-5) and adipocytokine signaling pathway (P_TWAS = 0.0392, P_CNAs = 0.0103).

CONCLUSIONS

Our study identified multiple DNHL associated genes and pathways, providing novel useful information for the pathogenetic studies of DNHL.

Emerging role of histone deacetylase inhibitors in the treatment of diffuse large B-cell lymphoma

Although current immunochemotherapy has increased the therapeutic efficacy in diffuse large B-cell lymphoma (DLBCL), there are still some patients who present unfavorable outcomes. Novel effective treatment strategies are needed to improve the prognosis of DLBCL. In this review, we discussed the functional mechanisms and therapeutic applications of histone deacetylases inhibitors (HDIs) in DLBCL from preclinical and clinical studies. The mechanistic rationale of HDIs involved a wide range of effects including the regulation of transcription factors, tumor suppressors, and cell surface molecules. Histone deacetylases inhibitors as monotherapy performed limited activity in the treatment of DLBCL in present clinical trials, but its combination with other regimens has emerged as potential treatment candidates with generally acceptable and manageable adverse effects. Further investigation on the anti-tumor mechanisms of HDIs and ongoing clinical trials will hopefully facilitate the application of HDIs in patients with DLBCL.

Successful Intensive Care Treatment of Severe Lactic Acidosis and Tumor Lysis Syndrome Related to Intravascular Lymphoma

Intravascular lymphoma is a rare disease that progresses to multiple organ dysfunction caused primarily by tumor cell proliferation in small blood vessels. Few studies have investigated critical care management of intravascular lymphoma. We describe a rare case of multiple organ failure due to intravascular lymphoma with severe lactic acidosis in a patient who survived. A 64-year-old man with impaired consciousness was diagnosed as having intravascular large B-cell lymphoma by means of a random skin biopsy. The patient arrived at our hospital's intensive care unit (ICU) with impaired consciousness, respiratory failure that required mechanical ventilation, and lactic acidosis that required renal replacement therapy. Mechanical ventilation and renal replacement therapy were continued in the ICU, and his respiratory status and circulatory dynamics eventually stabilized. However, his impaired consciousness and hyperlactatemia did not improve until after the start of chemotherapy with doxorubicin, cyclophosphamide, vincristine, prednisolone, and rituximab. Although he developed tumor lysis syndrome immediately after chemotherapy, his systemic condition was gradually stabilized by continued critical care management primarily comprising renal replacement therapy. He was weaned from ventilator support after a tracheotomy and moved to the general ward. Hematopoietic malignancy with hyperlactatemia has a very poor prognosis; however, hyperlactatemia and impaired consciousness were dramatically improved in this patient by critical care management and chemotherapy.

AutophagySMDB: a curated database of small molecules that modulate protein targets regulating autophagy

Macroautophagy/autophagy is a complex self-degradative mechanism responsible for clearance of non functional organelles and proteins. A range of factors influences the autophagic process, and disruptions in autophagy-related mechanisms lead to disease states, and further exacerbation of disease. Despite in-depth research into autophagy and its role in pathophysiological processes, the resources available to use it for therapeutic purposes are currently lacking. Herein we report the Autophagy Small Molecule Database (AutophagySMDB; http://www.autophagysmdb.org/ ) of small molecules and their cognate protein targets that modulate autophagy. Presently, AutophagySMDB enlists ~10,000 small molecules which regulate 71 target proteins. All entries are comprised of information such as EC50 (half maximal effective concentration), IC50 (half maximal inhibitory concentration), Kd (dissociation constant) and Ki (inhibition constant), IUPAC name, canonical SMILE, structure, molecular weight, QSAR (quantitative structure activity relationship) properties such as hydrogen donor and acceptor count, aromatic rings and XlogP. AutophagySMDB is an exhaustive, cross-platform, manually curated database, where either the cognate targets for small molecule or small molecules for a target can be searched. This database is provided with different search options including text search, advanced search and structure search. Various computational tools such as tree tool, cataloging tools, and clustering tools have also been implemented for advanced analysis. Data and the tools provided in this database helps to identify common or unique scaffolds for designing novel drugs or to improve the existing ones for autophagy small molecule therapeutics. The approach to multitarget drug discovery by identifying common scaffolds has been illustrated with experimental validation. Abbreviations: AMPK: AMP-activated protein kinase; ATG: autophagy related; AutophagySMDB: autophagy small molecule database; BCL2: BCL2, apoptosis regulator; BECN1: beclin 1; CAPN: calpain; MTOR: mechanistic target of rapamycin kinase; PPARG: peroxisome proliferator activated receptor gamma; SMILES: simplified molecular input line entry system; SQSTM1: sequestosome 1; STAT3: signal transducer and activator of transcription.

CUL4B regulates autophagy via JNK signaling in diffuse large B-cell lymphoma

Aberrant expression of CUL4B was identified in various types of solid cancers. Cumulative evidences support the oncogenic role of CUL4B in cancers, including regulation of cell proliferation and signal transduction. However, its clinical value and potential pathogenic mechanism in diffuse large B-cell lymphoma (DLBCL) have not been described previously. Therefore, we hypothesize that overexpressed CUL4B may contribute to the pathogenesis of DLBCL. The aim of this study is to assess the expression and the biological function of CUL4B in DLBCL progression. In our study, CUL4B overexpression was observed in DLBCL tissues, and its upregulation was closely associated with poor prognosis in patients. Furthermore, the functional roles of CUL4B was detected both in vitro and in vivo. We demonstrated that silencing CUL4B could not only induce cell proliferation inhibition, cell cycle arrest, and motility attenuation of DLBCL cells in vitro, but also decrease tumor growth in DLBCL xenografts mice. In addition, we identified that CUL4B may act as a potent inductor of JNK phosphorylation in regulation of autophagy. Our findings demonstrated a significant role of CUL4B in the development and progression of DLBCL. CUL4B may act as a useful biomarker and a novel therapeutic target in DLBCL.

Exclusive inhibition of PI3K/Akt/mTOR signaling is not sufficient to prevent PDGF-mediated effects on glycolysis and proliferation in colorectal cancer

Platelet-derived growth factor (PDGF) and signaling via its receptors plays a crucial role in tumor cell proliferation and thus may represent an attractive target besides VEGF/EGFR-based antibody therapies. In this study we analyzed the influence of PDGF in colorectal cancer. PDGF was expressed intensively in early and even more intensively in late stage primary CRCs. Like VEGF, PDGF enhanced human colon cancer proliferation, and increased oxidative glycolytic activity, and activated HIF1α and c-Myc in vitro. PDGF activated the PI3K/Akt/mTOR pathway while leaving MAPK signaling untouched. Further dissection showed that inhibition of Akt strongly impeded cancer cell growth while inhibition of PI3K did not. MAPK analysis suggested an inhibitory crosstalk between both pathways, thus explaining the different effects of the Akt and PI3K inhibitors on cancer cell proliferation. PDGF stimulates colon cancer cell proliferation, and prevents inhibitor induced apoptosis, resulting in tumor growth. Therefore inhibition of PDGF signaling seems to be a promising target in colorectal cancer therapy. However, due to the multifaceted nature of the intracellular PDGF signaling, careful intervention strategies are needed when looking into specific signaling pathways like PI3K/Akt/mTOR and MAPK.

Targeted Therapies in Adult B-Cell Malignancies

B-lymphocytes are programmed for the production of immunoglobulin (Ig) after antigen presentation, in the context of T-lymphocyte control within lymphoid organs. During this differentiation/activation process, B-lymphocytes exhibit different restricted or common surface markers, activation of cellular pathways that regulate cell cycle, metabolism, proteasome activity, and protein synthesis. All molecules involved in these different cellular mechanisms are potent therapeutic targets. Nowadays, due to the progress of the biology, more and more targeted drugs are identified, a situation that is correlated with an extended field of the targeted therapy. The full knowledge of the cellular machinery and cell-cell communication allows making the best choice to treat patients, in the context of personalized medicine. Also, focus should not be restricted to the immediate effects observed as clinical endpoints, that is, response rate, survival markers with conventional statistical methods, but it should consider the prediction of different clinical consequences due to other collateral drug targets, based on new methodologies. This means that new reflection and new bioclinical follow-up have to be monitored, particularly with the new drugs used with success in B-cell malignancies. This review discussed the principal aspects of such evident bioclinical progress.