Histone Deacetylase Inhibitor Research Articles

BCL6 confers resistance to HDAC inhibitors in DLBCL

Diffuse large B-cell lymphoma (DLBCL) is an aggressive non-Hodgkin lymphoma with limited response to chemotherapy. Histone acetylation is reduced in DLBCL. Chidamide, a histone deacetylase inhibitor, shows promise in lymphomas but needs further investigation for DLBCL. Our study indicated that chidamide effectively suppresses DLBCL both in vitro and in vivo. High-throughput RNA sequencing analysis provided comprehensive evidence that chidamide markedly influences crucial signaling pathways in DLBCL, including the MAPK, MYC and p53 pathway. Additionally, we observed substantial variability in the sensitivity of DLBCL cells to chidamide, and identified that elevated expression of BCL6 might confer resistance to chidamide in DLBCL. Moreover, our investigations revealed that BCL6 inhibited chidamide-induced histone acetylation by recruiting histone deacetylase (HDACs), leading to drug resistance in DLBCL cells. Furthermore, we found that lenalidomide targeted BCL6 degradation through the ubiquitination pathway and restore the sensitivity of drug-resistant DLBCL to chidamide. Collectively, these findings provided valuable insights into the global impact of chidamide on DLBCL and highlight the potential of targeting HDACs as a therapeutic strategy for DLBCL. Identifying BCL6 as a biomarker for predicting the response to chidamide and the combination therapy with BCL6 inhibition has the potential to lead to more personalized and effective treatments for DLBCL patients.

The epigenetic changes are affected by sex and valproic acid treatment in a rat model of post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) presents distinct sex-specific differences in both symptom expression and treatment outcomes, with the underlying biological mechanisms still remain unclear. Epigenetic modifications, particularly histone acetylation, have been increasingly recognized as critical factors in the pathophysiology of PTSD. Valproic acid (VPA), a potent histone deacetylase (HDAC) inhibitor, has shown promise in modulating epigenetic responses and improving therapeutic outcomes is PTSD, though its effect may differ between sexes. This study aimed to explore the sex-specific epigenetic changes in response to trauma and the impact of VPA treatment in a rat model of PTSD induced by predator scent stress. Sprague-Dawley rats of both sexes were randomly assigned to stressed and non-stressed groups and treated with either VPA (100 mg/kg) or vehicle. Anxiety levels were assessed using the elevated plus maze, followed by analysis of histone H3 and H4 acetylation, HDAC activity, and c-fos expression in the hippocampus. Our findings revealed that traumatic stress led to increased freezing time and anxiety levels, with more pronounced effects observed in females. Additionally, we have identified sex-specific differences in hippocampal epigenetic modifications; stressed females exhibited higher H3 acetylation, and VPA-treated stressed males showed increased H4 acetylation These results highlight the importance of considering sex differences in the epigenetic mechanism underlying PTSD and suggest that personalized therapeutic approaches may be necessary to address these complexities.

The Impact of Simultaneous Epigenetic and Epitranscriptomic Intervention in Breast Cancer Cells

Aim: Breast cancer remains a significant cause of mortality worldwide, necessitating the development of innovative therapeutic approaches. Epigenetic and epitranscriptomic regulation have emerged as promising avenues for novel treatments. Sodium Butyrate (NaB) and Meclofenamic Acid (MFA) have gained attention for their respective roles in epigenetic and epitranscriptomic modulation. NaB, a histone deacetylase inhibitor, serves as a critical regulator of chromatin remodeling and gene expression. MFA has been identified to be a potent inhibitor of the FTO enzyme. This inhibitory potential marks its role in epitranscriptomic regulation. This study aimed to investigate the potential effects of MFA and NaB, individually and in combination, on the MCF7 breast cancer cell line. Method: In order to investigate the cytotoxic and apoptotic effects of the combination treatment of MFA and NaB, cell viability assay, Annexin V analysis and Acridine Orange/DAPI staining were executed. Results: The results revealed that the combination treatment unexpectedly exhibited antagonistic effects. This was evidenced by a remarkable increase in cell viability and a decreased apoptotic response compared to individual treatments. The strongest antagonistic effect was observed when the cells were treated with 100 μM MFA and 2 mM NaB for a period of 48 hours (CI = 88.3). Conclusion: This study, for the first time, sheds light on the complex interaction between meclofenamic acid and sodium butyrate that reveals an unexpected antagonistic effect on MCF7 breast cancer cells. These findings challenge conventional concepts of synergistic interactions and underscore the complexity of drug combinations in breast cancer treatment.

Metavert synergises with standard cytotoxics in human PDAC organoids and is associated with transcriptomic signatures of therapeutic response

Despite some recent advances, pancreatic ductal adenocarcinoma (PDAC) remains a growing oncological challenge. New drugs capable of targeting more than one oncogenic pathway may be one way to improve patient outcomes. This study characterizes the effectiveness of Metavert a first-in-class dual inhibitor of GSK3-β and histone deacetylase in treating PDAC as a single agent or in combination with standard cytotoxics. Thirty-six Patient-Derived Organoids (hPDOs) characterised by RNASeq and whole exome sequencing were treated with Metavert alone or in combination with standard cytotoxics. Transcriptomic signatures (TS) representing sensitivity to Metavert alone or sensitivity to Metavert + irinotecan (IR) were evaluated in 47 patient samples, chemo-naïve in 26 and post-chemotherapy in 21 (gemcitabine=5; FOLFIRINOX=14, both=2) with companion multiplexed immunofluorescence and RNASeq data. Metavert combined with gemcitabine, irinotecan, 5FU, oxaliplatin, and paclitaxel was synergistic in the hPDOs. Basal-subtype hPDOs were more sensitive to Metavert alone whereas the Metavert+IR combination exhibited synergy in Classical-subtype hPDOs with increased apoptosis and autophagy. hPDO-derived TS evaluated in PDAC tissues demonstrated that Metavert-TSHi samples were enriched for mRNA splicing and DNA repair processes; they were associated with Basal-like tissues but also with GATA6+ve-chemo-naïve samples and were higher following gemcitabine but not FOLFIRINOX treatment. In contrast, Metavert+IR-TSHI samples were enriched for TP53 pathways; they were associated with Classical-like pretreatment samples and with GATA6+ve/KRT17+ve hybrid cell types following FOLFIRINOX, but not gemcitabine treatment, and were unrelated to transcriptional subtypes. Metavert as a single agent and in combination with irinotecan offers novel strategies for treating pancreatic cancer.

Histone deacetylase inhibitor, Trichostatin A mitigates ionizing radiation induced redox imbalance by regulating NRF2/GPX4/PINK1/PARKIN signaling in mice intestine.

Gastrointestinal-acute radiation syndrome (GI-ARS) caused by moderate to high doses of ionizing radiation exposurecontribute to early death in humans. GI injury is also a common adverse effect seen in cancer patients undergoing abdominal/pelvic radiotherapy. Currently, no countermeasure agents have been approved for medical management of GI-ARS. The present study aims to evaluate the mechanism of action of Trichostatin A(TSA), a pan histone deacetylaseinhibitor, against radiation-induced GI injury. TSA (150ng/kg bw) was administered to mice 1h and 24h after 15Gy abdominal irradiation. Expression of various markers of oxidative stress, mitochondrial dysfunction, and apoptosis were checked in the jejunum, and their possible regulation throughthe Nrf2 signaling pathway was evaluated. TSA administered post-irradiation (15Gy + TSA) elevated intestinal total antioxidant and glutathione levels by regulating the expression of Slc7A11 and antioxidant proteins, GCLC, GPX4, and TXNRD1. Improved mitochondrial membrane potential, ATP levels, downregulation of mitochondrial quality control proteins, (PINK1 and PARKIN), and differential regulation of the apoptotic proteins, (BAX, PUMA and BCL2) with reduced intestinal epithelial cell apoptosis in the TSA-adminstered groupwere observed. TSA also upregulated Nrf2 in the presence of its specific inhibitor, ML385, suggesting its involvement in regulating Nrf2 signaling during oxidative stress induced by radiation in intestine. H & E stained jejunumcross-sections revealed that TSA mitigated radiation-mediated intestinalinjury in mice. Present findingsindicate that TSA is beneficial in mitigating the damaging effects of ionizing radiation in the intestine.

Predicting the efficiency of chidamide in patients with angioimmunoblastic T-cell lymphoma using machine learning algorithm

BackgroundChidamide is subtype-selective histone deacetylase (HDAC) inhibitor that showed promising result in clinical trials to improve prognosis of angioimmunoblastic T-cell lymphoma (AITL) patients. However, in real world settings, contradictory reports existed as to whether chidamide improve overall survival (OS). Therefore, we aimed to develop an interpretable machine learning (Machine learning)–based model to predict the 2-year overall survival of AITL patients based on chidamide usage and baseline features.MethodsA total of 183 patients with AITL were randomly divided into training set and testing set. We used 5 ML algorithms to build predictive models. Recursive feature elimination (RFE) method was used to filter for the most important features. The ML models were interpreted and the relevance of the selected features was determined using the Shapley additive explanations (SHAP) method and the local interpretable model–agnostic explanationalgorithm.ResultsA total of 183 patients with newly diagnosed AITL from 2012 to 2022 from 3 centers in China were enrolled in our study. Seventy-one patients were dead within 2 years after diagnosis. Five ML algorithms were built based on chidamide usage and 16 baseline features to predict 2-year OS. Catboost model presented to be the best predictive model. After RFE screening, 12 variables demonstrated the best performance (AUC = 0.8651). Using chidamide ranked third among all the variables that correlated with 2-year OS.ConclusionThis study demonstrated that the Catboost model with 12 variables could effectively predict the 2-year OS of AITL patients. Combining chidamide in the treatment therapy was positively correlated with longer OS of AITL patients.

Pterostilbene improves neurological dysfunction and neuroinflammation after ischaemic stroke via HDAC3/Nrf1-mediated microglial activation.

Stroke is a type of acute brain damage that can lead to a series of serious public health challenges. Demonstrating the molecular mechanism of stroke-related neural cell degeneration could help identify a more efficient treatment for stroke patients. Further elucidation of factors that regulate microglia and nuclear factor (erythroid-derived 2)-like 1 (Nrf1) may lead to a promising strategy for treating neuroinflammation after ischaemic stroke. In this study, we investigated the possible role of pterostilbene (PTS) in Nrf1 regulation in cell and animal models of ischaemia stroke. We administered PTS, ITSA1 (an HDAC activator) and RGFP966 (a selective HDAC3 inhibitor) in a mouse model of middle cerebral artery occlusion-reperfusion (MCAO/R) and a model of microglial oxygen‒glucose deprivation/reperfusion (OGD/R). The brain infarct size, neuroinflammation and microglial availability were also determined. Dual-luciferase reporter, Nrf1 protein stability and co-immunoprecipitation assays were conducted to analyse histone deacetylase 3 (HDAC3)/Nrf1-regulated Nrf1 in an OGD/R-induced microglial injury model. We found that PTS decreased HDAC3 expression and activity, increased Nrf1 acetylation in the cell nucleus and inhibited the interaction of Nrf1 with p65 and p65 accumulation, which reduced infarct volume and neuroinflammation (iNOS/Arg1, TNF-α and IL-1β levels) after ischaemic stroke. Furthermore, the CSF1R inhibitor PLX5622 induced elimination of microglia and attenuated the therapeutic effect of PTS following MCAO/R. In the OGD/R model, PTS relieved OGD/R-induced microglial injury and TNF-α and IL-1β release, which were dependent on Nrf1 acetylation through the upregulation of HDAC3/Nrf1 signalling in microglia. However, the K105R or/and K139R mutants of Nrf1 counteracted the impact of PTS in the OGD/R-induced microglial injury model, which indicates that PTS treatment might be a promising strategy for ischaemia stroke therapy. The HDAC3/Nrf1 pathway regulates the stability and function of Nrf1 in microglial activation and neuroinflammation, which may depend on the acetylation of the lysine 105 and 139 residues in Nrf1. This mechanism was first identified as a potential regulatory mechanism of PTS-based neuroprotection in our research, which may provide new insight into further translational applications of natural products such as PTS.

Stack-HDAC3i: A high-precision identification of HDAC3 inhibitors by exploiting a stacked ensemble-learning framework

Epigenetics involves reversible modifications in gene expression without altering the genetic code itself. Among these modifications, histone deacetylases (HDACs) play a key role by removing acetyl groups from lysine residues on histones. Overexpression of HDACs is linked to the proliferation and survival of tumor cells. To combat this, HDAC inhibitors (HDACi) are commonly used in cancer treatments. However, pan-HDAC inhibition can lead to numerous side effects. Therefore, isoform-selective HDAC inhibitors, such as HDAC3i, could be advantageous for treating various medical conditions while minimizing off-target effects. To date, computational approaches that use only the SMILES notation without any experimental evidence have become increasingly popular and necessary for the initial discovery of novel potential therapeutic drugs. In this study, we develop an innovative and high-precision stacked-ensemble framework, called Stack-HDAC3i, which can directly identify HDAC3i using only the SMILES notation. Using an up-to-date benchmark dataset, we first employed both molecular descriptors and Mol2Vec embeddings to generate feature representations that cover multi-view information embedded in HDAC3i, such as structural and contextual information. Subsequently, these feature representations were used to train baseline models using nine popular ML algorithms. Finally, the probabilistic features derived from the selected baseline models were fused to construct the final stacked model. Both cross-validation and independent tests showed that Stack-HDAC3i is a high-accuracy prediction model with great generalization ability for identifying HDAC3i. Furthermore, in the independent test, Stack-HDAC3i achieved an accuracy of 0.926 and Matthew’s correlation coefficient of 0.850, which are 0.44–6.11% and 0.83–11.90% higher than its constituent baseline models, respectively.

Epigenetic Modulations in Breast Cancer: An Emerging Paradigm in Therapeutic Implications.

Breast cancer, a heterogeneous and intricate disease, ranks among the leading causes of mortality in women. Restricted therapeutic choices, drug resistance, recurrence, and metastasis are the predominant conditions that lead to mortality. Accumulating evidence has shown breast cancer initiation and progression happen through a multifaceted and intricate process that involves numerous genetic and epigenetic alterations. The modulation of gene expression through epigenetic modifications, encompassing DNA methylation, histone alterations, and non-coding RNA regulation, has emerged as a fascinating field that represents a new avenue for breast cancer therapy. This review emphasizes various aberrant epigenetic regulations implicated in the onset and advancement of breast cancer. The critical epigenetic modifications closely associated with estrogen signaling, epithelial-to-mesenchymal transition (EMT), cancer stemness, and drug resistance have been discussed extensively. Moreover, it highlights current epi-drugs, including DNA modifying agents, histone acetyltransferase inhibitors, histone deacetylase inhibitors, histone methyltransferase inhibitors, and histone demethyltransferase inhibitors used for breast cancer treatment. Nonetheless, we described current investigations pertaining to combination therapy employing epi-drugs and future challenges.

Vorinostat Treatment of Gastric Cancer Cells Leads to ROS-Induced Cell Inhibition and a Complex Pattern of Molecular Alterations in Nrf2-Dependent Genes.

Histone deacetylase inhibitors (HDACi) show high antineoplastic potential in preclinical studies in various solid tumors, including gastric carcinoma; however, their use in clinical studies has not yet yielded convincing efficacies. Thus, further studies on cellular/molecular effects of HDACi are needed, for improving clinical efficacy and identifying suitable combination partners. Here, we investigated the role of oxidative stress in gastric cancer cells upon treatment with HDACi. A particular focus was laid on the role of the Nrf2 pathway, which can mediate resistance to cell-inhibitory effects of reactive oxidative species (ROS). Using fluorescence-based ROS sensors, oxidative stress was measured in human gastric cancer cell lines. Activation of the Nrf2 pathway was monitored in luciferase reporter assays as well as by mRNA and proteomic expression analyses of Nrf2 regulators and Nrf2-induced genes. Furthermore, the effects of ROS scavenger N-acetyl-L-cysteine (NAC) and Nrf2-knockdown on HDACi-dependent antiproliferative effects were investigated in colorimetric formazan-based and clonogenic survival assays. HDACi treatment led to increased oxidative stress levels and consequently, treatment with NAC reduced cytotoxicity of HDACi. In addition, vorinostat treatment stimulated expression of a luciferase reporter under the control of an antioxidative response element, indicating activation of the Nrf2 system. This Nrf2 activation was only partially reversible by treatment with NAC, suggesting ROS independent pathways to contribute to HDACi-promoted Nrf2 activation. In line with its cytoprotective role, Nrf2 knockdown led to a sensitization against HDACi. Accordingly, the expression of antioxidant and detoxifying Nrf2 target genes was upregulated upon HDACi treatment. In conclusion, oxidative stress induction upon HDAC inhibition contributes to the antitumor effects of HDAC inhibitors, and activation of Nrf2 represents a potentially important adaptive response of gastric cancer cells in this context.

Development of peptoid-based heteroaryl-decorated histone deacetylase (HDAC) inhibitors with dual-stage antiplasmodial activity

Dynamics of epigenetic modifications such as acetylation and deacetylation of histone proteins have been shown to be crucial for the life cycle development and survival of Plasmodium falciparum, the deadliest malaria parasite. In this study, we present a novel series of peptoid-based histone deacetylase (HDAC) inhibitors incorporating nitrogen-containing bicyclic heteroaryl residues as a new generation of antiplasmodial peptoid-based HDAC inhibitors. We synthesized the HDAC inhibitors by an efficient multicomponent protocol based on the Ugi four-component reaction. The subsequent screening of 16 compounds from our mini-library identified 6i as the most promising candidate, demonstrating potent activity against asexual blood-stage parasites (IC50Pf3D7 = 30 nM; IC50PfDd2 = 98 nM), low submicromolar activity against liver-stage parasites (IC50PbEEF = 0.25 μM), excellent microsomal stability (t1/2 > 60 min), and low cytotoxicity to HEK293 cells (IC50 = 136 μM).

Light regulates widespread plant alternative polyadenylation through the chloroplast

Transcription of eukaryotic protein-coding genes generates immature mRNAs that are subjected to a series of processing events, including capping, splicing, cleavage, and polyadenylation (CPA), and chemical modifications of bases. Alternative polyadenylation (APA) greatly contributes to mRNA diversity in the cell. By determining the length of the 3' untranslated region, APA generates transcripts with different regulatory elements, such as miRNA and RBP binding sites, which can influence mRNA stability, turnover, and translation. In the model plant Arabidopsis thaliana, APA is involved in the control of seed dormancy and flowering. In view of the physiological importance of APA in plants, we decided to investigate the effects of light/dark conditions and compare the underlying mechanisms to those elucidated for alternative splicing (AS). We found that light controls APA in approximately 30% of Arabidopsis genes. Similar to AS, the effect of light on APA requires functional chloroplasts, is not affected in mutants of the phytochrome and cryptochrome photoreceptor pathways, and is observed in roots only when the communication with the photosynthetic tissues is not interrupted. Furthermore, mitochondrial and TOR kinase activities are necessary for the effect of light. However, unlike AS, coupling with transcriptional elongation does not seem to be involved since light-dependent APA regulation is neither abolished in mutants of the TFIIS transcript elongation factor nor universally affected by chromatin relaxation caused by histone deacetylase inhibition. Instead, regulation seems to correlate with changes in the abundance of constitutive CPA factors, also mediated by the chloroplast.

Searching for Novel HDAC6/Hsp90 Dual Inhibitors with Anti-Prostate Cancer Activity: In Silico Screening and In Vitro Evaluation.

Prostate cancer (PCA) is one of the most prevalent types of male cancers. While current treatments for early-stage PCA are available, their efficacy is limited in advanced PCA, mainly due to drug resistance or low efficacy. In this context, novel valuable therapeutic opportunities may arise from the combined inhibition of histone deacetylase 6 (HDAC6) and heat shock protein 90 (Hsp90). These targets are mutually involved in the regulation of several processes in cancer cells, and their inhibition is demonstrated to provide synergistic effects against PCA. On these premises, we performed an extensive in silico virtual screening campaign on commercial compounds in search of dual inhibitors of HDAC6 and Hsp90. In vitro tests against recombinant enzymes and PCA cells with different levels of aggressiveness allowed the identification of a subset of compounds with inhibitory activity against HDAC6 and antiproliferative effects towards LNCaP and PC-3 cells. None of the candidates showed appreciable Hsp90 inhibition. However, the discovered compounds have low molecular weight and a chemical structure similar to that of potent Hsp90 blockers. This provides an opportunity for structural and medicinal chemistry optimization in order to obtain HDAC6/Hsp90 dual modulators with antiproliferative effects against prostate cancer. These findings were discussed in detail in the study.

Epigenetics and Control of Tumor Angiogenesis in Melanoma: An Update with Therapeutic Implications.

Angiogenesis, the formation of new blood vessels from pre-existing ones, is a crucial process in the progression and metastasis of melanoma. Recent research has highlighted the significant role of epigenetic modifications in regulating angiogenesis. This review comprehensively examines the current understanding of how epigenetic mechanisms, including DNA methylation, histone modifications, and non-coding RNAs, influence angiogenic pathways in melanoma. DNA methylation, a key epigenetic modification, can silence angiogenesis inhibitors such as thrombospondin-1 and TIMP3 while promoting pro-angiogenic factors like vascular endothelial growth factor (VEGF). Histone modifications, including methylation and acetylation, also play a pivotal role in regulating the expression of angiogenesis-related genes. For instance, the acetylation of histones H3 and H4 is associated with the upregulation of pro-angiogenic genes, whereas histone methylation patterns can either enhance or repress angiogenic signals, depending on the specific histone mark and context. Non-coding RNAs, particularly microRNAs (miRNAs) further modulate angiogenesis. miRNAs, such as miR-210, have been identified as key regulators, with miR-9 promoting angiogenesis by targeting E-cadherin and enhancing the expression of VEGF. This review also discusses the therapeutic potential of targeting epigenetic modifications to inhibit angiogenesis in melanoma. Epigenetic drugs, such as DNA methyltransferase inhibitors (e.g., 5-azacytidine) and histone deacetylase inhibitors (e.g., Vorinostat), have shown promise in preclinical models by reactivating angiogenesis inhibitors and downregulating pro-angiogenic factors. Moreover, the modulation of miRNAs and lncRNAs presents a novel approach for anti-angiogenic therapy.

Microbiota-derived butyrate inhibits cDC development via HDAC inhibition, diminishing their ability to prime T cells

Conventional dendritic cells (cDC) are central to maintaining the balance between protective immune responses and tolerance to harmless antigens, especially in the intestine. Short chain fatty acids (SCFAs) such as butyrate play critical roles in regulating intestinal immunity, but the underlying mechanisms remain unclear. Here we demonstrate that microbiota-derived butyrate alters intestinal cDC populations in vivo resulting in decreased numbers of the cDC2 lineage. By establishing a novel in vitro culture model, we show that butyrate has a direct and selective ability to repress the development of cDC2 from cDC precursors, an effect that is independent of G-protein coupled receptors (GPCRs) and is due to inhibition of histone deacetylase 3. Finally, cDC derived from pre-cDC in the presence of butyrate in vitro express lower levels of costimulatory molecules and have a decreased ability to prime naïve T cells. Together, our data show that butyrate affects the developmental trajectory of cDC, selectively repressing the cDC2 lineage and reducing their ability to stimulate T cells. These properties may help explain the ability of butyrate to maintain homeostasis in the intestine.

Mass Spectrometry-based Profiling of Single-cell Histone Post-translational Modifications to Dissect Chromatin Heterogeneity.

Single-cell proteomics confidently quantifies cellular heterogeneity, yet precise quantification of post-translational modifications, such as those deposited on histone proteins, has remained elusive. Here, we developed a robust mass spectrometry-based method for the unbiased analysis of single-cell histone post-translational modifications (schPTM). schPTM identifies both single and combinatorial histone post-translational modifications (68 peptidoforms in total), which includes nearly all frequently studied histone post-translational modifications with comparable reproducibility to traditional bulk experiments. As a proof of concept, we treated cells with sodium butyrate, a histone deacetylase inhibitor, and demonstrated that our method can i) distinguish between treated and non-treated cells, ii) identify sub-populations of cells with heterogeneous response to the treatment, and iii) reveal differential co-regulation of histone post-translational modifications in the context of drug treatment. The schPTM method enables comprehensive investigation of chromatin heterogeneity at single-cell resolution and provides further understanding of the histone code.

Isoalantolactone/hydroxamic acid hybrids as potent dual STAT3/HDAC inhibitors and self-assembled nanoparticles for cancer therapy

Conventional chemotherapy, especially with natural anticancer drugs, usually suffers from poor bioavailability and low tumor accumulation. To address these limitations, we developed a novel approach for modifying natural products in which amphiphilic hydroxamic acid hybrids based on a natural product: isoalantolactone (IAL) were rationally designed. Compound 18 is identified as a highly potent dual signal transducer and activator of transcription 3 (STAT3)/histone deacetylases (HDAC) inhibitor and induces autophagy and apoptosis. 18 exhibits higher antitumor potency than IAL and the hydroxamic acid SAHA in vitro and in vivo. Furthermore, 18 self-assembled in water to form nanoparticles (18 NPs), which facilitated the accumulation of drugs in tumor tissues and promoted their cellular uptake, resulting in superior anticancer efficacy compared to free 18. Compared to drug-drug conjugates, hydroxamic acid hybrids have a smaller molecular weight and can synergize with various anticancer drugs. Overall, these findings indicate that 18 utilizing nanomedicines and dual-target drugs provide an efficient strategy for the rational design of dual-target drugs and the modification of natural products.

Acetylation of Steroidogenic Acute Regulatory Protein Sensitizes 17β-Estradiol Regulation in Hormone-Sensitive Breast Cancer Cells.

An imbalance in estrogen signaling is a critical event in breast tumorigenesis. The majority of breast cancers (BCs) are hormone-sensitive; they majorly express the estrogen receptor (ER+) and are activated by 17β-estradiol (E2). The steroidogenic acute regulatory protein (StAR) mediates the rate-limiting step in steroid biosynthesis. The dysregulation of the epigenetic machinery, modulating E2 levels, is a primary occurrence for promoting breast tumorigenesis. StAR expression, concomitant with E2 synthesis, was reported to be aberrantly high in human and mouse hormone-dependent BC cells compared with their non-cancerous counterparts. However, the mechanism of action of StAR remains poorly understood. We discovered StAR as an acetylated protein and have identified a number of lysine (K) residues that are putatively acetylated in malignant and non-malignant breast cells, using LC-MS/MS (liquid chromatography-tandem mass spectrometry), suggesting they differently influence E2 synthesis in mammary tissue. The treatment of hormone-sensitive MCF7 cells with a variety of histone deacetylase inhibitors (HDACIs), at therapeutically and clinically relevant doses, identified a few additional StAR acetylated lysine residues. Among a total of fourteen StAR acetylomes undergoing acetylation and deacetylation, K111 and K253 were frequently recognized either endogenously or in response to HDACIs. Site-directed mutagenesis studies of these two StAR acetylomes, pertaining to K111Q and K253Q acetylation mimetic states, resulted in increases in E2 levels in ER+ MCF7 and triple negative MB-231 BC cells, compared with their values seen with human StAR. Conversely, these cells carrying K111R and K253R deacetylation mutants diminished E2 biosynthesis. These findings provide novel and mechanistic insights into intra-tumoral E2 regulation by elucidating the functional importance of this uncovered StAR post-translational modification (PTM), involving acetylation and deacetylation events, underscoring the potential of StAR as a therapeutic target for hormone-sensitive BC.

Multi-omics and pharmacological characterization of patient-derived glioma cell lines

Glioblastoma (GBM) is the most common brain tumor and remains incurable. Primary GBM cultures are widely used tools for drug screening, but there is a lack of genomic and pharmacological characterization for these primary GBM cultures. Here, we collect 50 patient-derived glioma cell (PDGC) lines and characterize them by whole genome sequencing, RNA sequencing, and drug response screening. We identify three molecular subtypes among PDGCs: mesenchymal (MES), proneural (PN), and oxidative phosphorylation (OXPHOS). Drug response profiling reveals that PN subtype PDGCs are sensitive to tyrosine kinase inhibitors, whereas OXPHOS subtype PDGCs are sensitive to histone deacetylase inhibitors, oxidative phosphorylation inhibitors, and HMG-CoA reductase inhibitors. PN and OXPHOS subtype PDGCs stably form tumors in vivo upon intracranial transplantation into immunodeficient mice, whereas most MES subtype PDGCs fail to form tumors in vivo. In addition, PDGCs cultured by serum-free medium, especially long-passage PDGCs, carry MYC/MYCN amplification, which is rare in GBM patients. Our study provides a valuable resource for understanding primary glioma cell cultures and clinical translation and highlights the problems of serum-free PDGC culture systems that cannot be ignored.

Epigenetic mechanisms differentially regulate blood pressure and renal dysfunction in male and female Npr1 haplotype mice.

We determined the epigenetic mechanisms regulating mean arterial pressure (MAP) and renal dysfunction in guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA) gene-targeted mice. The Npr1 (encoding NPRA) gene-targeted mice were treated with class 1 specific histone deacetylase inhibitor (HDACi) mocetinostat (MGCD) to determine the epigenetic changes in a sex-specific manner. Adult male and female Npr1 haplotype (1-copy; Npr1+/-), wild-type (2-copy; Npr1+/+), and gene-duplicated heterozygous (3-copy; Npr1++/+) mice were intraperitoneally injected with MGCD (2 mg/kg) for 14 days. BP, renal function, histopathology, and epigenetic changes were measured. One-copy male mice showed significantly increased MAP, renal dysfunction, and fibrosis than 2-copy and 3-copy mice. Furthermore, HDAC1/2, collagen1alpha-2 (Col1α-2), and alpha smooth muscle actin (α-SMA) were significantly increased in 1-copy mice compared with 2-copy controls. The expression of antifibrotic microRNA-133a was attenuated in 1-copy mice but to a greater extent in males than females. NF-κB was localized at significantly lower levels in cytoplasm than in the nucleus with stronger DNA binding activity in 1-copy mice. MGCD significantly lowered BP, improved creatinine clearance, and repaired renal histopathology. The inhibition of class I HDACs led to a sex-dependent distinctive stimulation of acetylated positive histone marks and inhibition of methylated repressive histone marks in Npr1 1-copy mice; however, it epigenetically lowered MAP, repaired renal fibrosis, and proteinuria and suppressed NF-kB differentially in males versus females. Our results suggest a role for epigenetic targets affecting hypertension and renal dysfunction in a sex-specific manner.