Histone Deacetylase Inhibitor Research Articles

Molecular Targets of Valeric Acid: A Bioactive Natural Product for Endocrine, Metabolic, and Immunological Disorders.

Postbiotics produced by gut microbiota have exhibited diverse pharmacological activities. Valeric acid, a postbiotic material produced by gut microbiota and some plant species like valerian, has been explored to have diverse pharmacological activities. This narrative review aims to summarise the beneficial role of valeric acid for different health conditions along with its underlying mechanism. In order to get ample scientific evidence, various databases like Science Direct, PubMed, Scopus, Google Scholar and Google were exhaustively explored to collect relevant information. Collected data were arranged and analyzed to reach meaningful a conclusion regarding the bioactivity profiling of valeric acid, its mechanism, and future prospects. Valeric acid belongs to short-chain fatty acids (SCFAs) compounds like acetate, propionate, butyrate, pentanoic (valeric) acid, and hexanoic (caproic) acid. Valeric acid has been identified as one of the potent histone deacetylase (HDAC) inhibitors. In different preclinical in -vitro and in-vivo studies, valeric acid has been found to have anti-cancer, anti-diabetic, antihypertensive, anti-inflammatory, and immunomodulatory activity and affects molecular pathways of different diseases like Alzheimer's, Parkinson's, and epilepsy. These findings highlight the role of valeric acid as a potential novel therapeutic agent for endocrine, metabolic and immunity-related health conditions, and it must be tested under clinical conditions to develop as a promising drug.

ClassIIb histone deacetylase participates in perioperative neurocognitive disorders in elderly mice via HSP90/GR signaling pathway.

Multiple factors contribute to the development of perioperative neurocognitive disorders (PND). This study was designed to investigate whether Histone Deacetylase 6 (HDAC6) was involved in the formation of postoperative cognitive dysfunction in elderly mice by regulating the degree of acetylation of heat shock protein (HSP90) and related protein functions and quantities. C57BL/6J male mice were randomly divided into six groups: control naive (group Control), anesthesia (group Anesthesia), splenectomy surgery (group Surgery), splenectomy surgery plus dissolvent (group Vehicles), splenectomy surgery plus the inhibitor ACY-1215 (group Ricolinostat), and splenectomy surgery plus the inhibitor RU-486(group Mifepristone). After the mice were trained for Morris Water Maze (MWM) test for five days, anesthesia and operational surgery were carried out the following day. Cognitive function was assessed on the 1st, 3rd and 7th days post-surgery. The hippocampi were harvested on days 1, 3, and 7 post-surgeries for Western blots and ELISA assays. Mice with the splenectomy surgery displayed the activation of the hypothalamic-pituitary-adrenal axis (HPA-axis), marked an increase in adrenocorticotropic hormone (ACTH), glucocorticoid, mineralocorticoid at the molecular level and impaired spatial memory in the MWM test. The hippocampus of surgical groups showed a decrease in acetylated HSP90, a rise in glucocorticoid receptor (GR)-HSP90 association, and an increase in GR phosphorylation and translocation. HDAC6 was increased after the surgical treated. Using two specific inhibitors, HDAC6 inhibitor Ricolinostat (ACY-1215) and GR inhibitor Mifepristone (RU-486), can partially mitigate the effects caused by surgical operation. Abdominal surgery may impair hippocampal spatial memory, possibly through the HDAC6-triggered increase in the function of HSP90, consequently strengthening the negative role of steroids in cognitive function. Targeting HDAC6- HSP90/GR signaling may provide a potential avenue for the treatment of the impairment of cognitive function after surgery.

The loss of hepatitis B virus receptor NTCP/SLC10A1 in human liver cancer cells is due to epigenetic silencing

ABSTRACT Human Na+-taurocholate cotransporting polypeptide (hNTCP) is predominantly expressed in hepatocytes, maintaining bile salt homeostasis and serving as a receptor for hepatitis B virus (HBV). hNTCP expression is downregulated during hepatocellular carcinoma (HCC) development. In this study, we investigated the molecular mechanisms underlying hNTCP dysregulation using HCC tissues and cell lines, and primary human hepatocytes (PHHs). Firstly, we observed a significant reduction of hNTCP in HCC tumors compared to adjacent and normal tissues. Additionally, h NTCP mRNA levels were markedly lower in HepG2 cells compared to PHHs, which was corroborated at the protein level by immunoblotting. Sanger sequencing confirmed identical sequences for h NTCP promoter, exons, and mRNA coding sequences between PHH and HepG2 cells, indicating no mutations or splicing alterations. We then assessed the epigenetic status of h NTCP . The h NTCP promoter, with low CG content, showed no significant methylation differences between PHH and HepG2 cells. Chromatin immunoprecipitation coupled with qPCR (ChIP-qPCR) revealed a loss of activating histone posttranslational modification (PTM) H3K27ac near the h NTCP transcription start site (TSS) in HepG2 cells. This loss was also confirmed in HCC tumor cells compared to adjacent and background cells. Treating HepG2 cells with histone deacetylase inhibitors enhanced H3K27ac accumulation and glucocorticoid receptor (GR) binding at the h NTCP TSS, significantly increasing h NTCP mRNA and protein levels, and rendering the cells susceptible to HBV infection. In summary, histone PTM-related epigenetic mechanisms play a critical role in hNTCP dysregulation in liver cancer cells, providing insights into hepatocarcinogenesis and its impact on chronic HBV infection. IMPORTANCE HBV is a hepatotropic virus that infects human hepatocytes expressing the viral receptor hNTCP. Without effective antiviral therapy, chronic HBV infection poses a high risk of liver cancer. However, most liver cancer cell lines, including HepG2 and Huh7, do not support HBV infection due to the absence of hNTCP expression, and the mechanism underlying this defect remains unclear. This study demonstrates a significant reduction of hNTCP in hepatocellular carcinoma samples and HepG2 cells compared to normal liver tissues and primary human hepatocytes. Despite identical h NTCP genetic sequences, epigenetic analyses revealed a loss of the activating histone modification H3K27ac near the h NTCP transcription start site in cancer cells. Treatment with histone deacetylase inhibitors restored H3K27ac levels, reactivated h NTCP expression, and rendered HepG2 cells susceptible to HBV infection. These findings highlight the role of epigenetic modulation in h NTCP dysregulation, offering insights into hepatocarcinogenesis and its implications for chronic HBV infection.

Sintilimab plus GemOx is an effective salvage therapy in patients with refractory/relapsing nodal peripheral T cell lymphomas

PurposeThe retrospective study was to explore the effectiveness and safety of GemOx (gemcitabine, oxaliplatin) plus sintilimab (belongs to the class of drugs known as immune checkpoint inhibitors, particularly targeting the PD-1 receptor) in relapse or refractory nodal PTCLs.MethodsPatients with nodal PTCL who initiated salvage therapy with sintilimab and GemOx between January 2020 to September 2021 were identified from the database of the hematology department of the Second Affiliated Hospital of Zhejiang University School of Medicine. All patients received 2–4 cycles (3 weeks/cycle) of treatment of sintilimab (200 mg, I.V, D1) in combination with GemOx. Treatment response was assessed every six weeks during the salvage treatment phase. Eligible patients received maintenance therapy according to the investigator’s decision. Follow-ups were routinely conducted every three months.Results31 patients with r/r nodal PTCLs were enrolled, including 23 PTCL-NOS, 4 AITL, and 4 ALCL. 21 (67.7%) patients received at least two lines of therapy. 71.0% (95% CI, 53.4%-83.9%) of patients documented objective response of 2–4 cycles of sintilimab plus GemOx therapy, including 9 complete response and 13 partial response. 21 (67.7%) patients received consolidation therapy, including 5 autologous stem-cell transplantation and 12 histone deacetylase inhibitors. After a median 25.6 months follow-up, the median PFS was 22.0 (95% CI,11.8–24.7) months, and the median OS was 26.2 (95% CI, 24.4 –NA) months. 29 (93.5%) patients experienced at least one adverse event, and 26 (83.9% patients only had mild (grade 1–2) AEs.Univariable Cox regression showed the progression risk of AITL is 22.7 (3.9- 131.0, p < 0.01) times of PTCL-NOS, while the HR of ALCL was 1.14 (0.33–3.96,p = 0.833).ConclusionSintilimab plus GemOx showed encouraging activity and manageable toxicity for patients with r/r PTCL.

Development of new pyrazoles as class I HDAC inhibitors: Synthesis, molecular modeling, and biological characterization in leukemia cells.

Class I histone deacetylases (HDACs) are considered promising targets in current cancer research. To obtain subtype-selective and potent HDAC inhibitors, we used the aminobenzamide scaffold as the zinc-binding group and prepared new derivatives with a pyrazole ring as the linking group. The synthesized compounds were analyzed in vitro using an enzymatic assay against HDAC1, -2, and -3. Compounds 12b, 15b, and 15i were found to be potent HDAC1 inhibitors, also in comparison to the reference compounds entinostat and tacedinaline, with IC50 values of 0.93, 0.22, and 0.68 μM, respectively. The best compounds were measured for their cellular effect and target engagement in acute myeloid leukemia (AML) cells. In addition, we studied the interaction of the compounds with HDAC subtypes using docking and molecular dynamic simulations. In summary, we have developed a new chemotype of HDAC1 inhibitors that can be used for further structure-based optimization.

Low-dose SAHA enhances CD8+ T cell-mediated antitumor immunity by boosting MHC I expression in non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is a highly aggressive type of lung cancer with poor responses to traditional therapies such as surgery, radiotherapy, and chemotherapy. While immunotherapy has become an effective approach for treating multiple types of cancer, solid tumors frequently exhibit immune escape through various mechanisms, including downregulation of MHC I expression. However, whether the upregulation of MHC I expression can improve the immunotherapeutic effect on NSCLC remains unexplored. Suberoylanilide hydroxamic acid (SAHA) is a potent histone deacetylase (HDAC) inhibitor that has been applied clinically to treat lymphoma, but a high dose of SAHA kills tumor cells and normal cells without preference. Here, we report that low-dose SAHA enhances CD8+ T cell-mediated antitumor immunity by upregulating MHC I expression in NSCLC cells. Flow cytometric analysis, quantitative real-time PCR and western blot were used to analyze the expression of MHC I, STAT1 and Smad2/3 in both human and mouse NSCLC cell lines after SAHA treatment. The nuclear translocation of phosphorylated STAT1 and Smad2/3 was investigated by western blot and immunofluorescence staining. The mechanisms underlying STAT1 and Smad2/3 upregulation were analyzed through database searches and chromatin immunoprecipitation-qPCR. Finally, we assessed the antitumor effect of specific CD8+ T cells with SAHA treatment in vivo and in vitro. We showed that low-dose SAHA upregulated the expression of MHC I in NSCLC cell lines without affecting cell viability. We also provided evidence that high levels of MHC I induced by SAHA promoted the activation, proliferation, and cytotoxicity of specific CD8+ T cells in mouse models. Mechanistically, low-dose SAHA increased the levels of H3K9ac and H3K27ac in the promoters of the STAT1, Smad2 and Smad3 genes in NSCLC cells by inhibiting HDAC activity, resulting in elevated expression levels of STAT1, Smad2 and Smad3. The nuclear translocation of phosphorylated STAT1 and Smad2/3 markedly upregulated the expression of MHC I in NSCLC cells. Low-dose SAHA enhances CD8+ T cell-mediated antitumor immunity by boosting MHC I expression in NSCLC cells. Thus, we revealed a key mechanism of SAHA-mediated enhanced antitumor immunity, providing insights into a novel immunotherapy strategy for NSCLC.

Abstract B062: Low dose dual epigenetic therapy utilizing hypomethylating agents and HDAC inhibitors prolong survival in an orthotopic PDAC model and alter the tumor microenvironment

Abstract Background: We have previously studied the effect of hypomethylating agent Decitabine (5- aza-dC; DAC) on pancreatic cancer using the KPC model (KrasG12D/+;Trp53R172H/+;Pdx1- Cre) and observed increased CD4+/CD8+ TILs, greater PD1 expression and slowed tumor growth with increased tumor necrosis. Subsequently we showed a significant survival benefit with DAC+αPD1 compared to either single agent. However, we identified a specific myeloid cell population initially identified by Chi3l3 expression that may be responsible for treatment resistance or escape. Based on prior observations of synergy specifically affecting tumor infiltrating myeloid and lymphoid cells, we focused on identifying a dual epigenetic strategy (a combination of DAC plus histone deacetylase inhibitors (HDACi)) to enhance immunological synergy and test their treatment efficacy with αPD1. Methods: We used a combination primary KPC-derived cell lines, bone marrow (BMDM) and peritoneum derived (PM) myeloid cells and T cells in co-culture systems to assess cytotoxic synergy (Bliss/Lowe consensus) and immune effects (cytokine release, myeloid cell polarization and T cell activation) to evaluate combinations of DAC+HDACi. The KPC orthotopic model relying on US monitoring of tumor size for standardized initiation of therapy was used for survival analysis and profiling in treatment combinations of DAC+HDACi+αPD1. Results: We showed that hypomethylation therapy exerts a primarily paracrine effect on myeloid cells and this polarization results in a decrease in DAC–induced T cell activation. We therefore selected HDAC inhibitors that in combination with DAC alter this paracrine effect. We selected specific HDAC inhibitors based on induction of class of HDAC expression following hypomethylation therapy, highest Bliss synergy scores at low doses and reversal of cytokine release, M2 polarization and T cell inactivation. Three HDAC inhibitors were chosen for in vivo testing, Domatinostat, Pracinostat and Entinostat. Using the treatment paradigm of ultra-low dose DAC+ HDACi (mainly to minimize toxicity) combined with αPD1 in the KPC orthotopic model we show that the triple combination (DAC + Entinostat + αPD1) is well-tolerated and results in a significant survival benefit compared to single and dual agent combinations. In addition, we also demonstrate a reduction in the Chi3l3 expressing myeloid cell population. Conclusions: Our results show that the combination of hypomethylating agent plus HDAC inhibitor has several beneficial effects on the tumor immune response in PDAC. HDAC inhibitors specifically reduce the suppressive myeloid cell population we previously identified after DAC therapy. The combination of dual low dose epigenetic therapy using a hypomethylating agent plus HDAC inhibitor followed by αPD1 results in significant survival benefit in the orthotopic KPC model. Citation Format: Stephen Muzyka, Arturo Orlacchio, Amanda Ackermann, Yasmine Chinda, Yoona Shim, Igor Dolgalev, Tamas Gonda. Low dose dual epigenetic therapy utilizing hypomethylating agents and HDAC inhibitors prolong survival in an orthotopic PDAC model and alter the tumor microenvironment [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr B062.

Unbiased screening identifies regulators of cell-cell adhesion and treatment options in pemphigus

Cell-cell junctions, and specifically desmosomes, are crucial for robust intercellular adhesion. Desmosomal function is compromised in the autoimmune blistering skin disease pemphigus vulgaris. We combine whole-genome knockout screening and a promotor screen of the desmosomal gene desmoglein 3 in human keratinocytes to identify novel regulators of intercellular adhesion. Kruppel-like-factor 5 (KLF5) directly binds to the desmoglein 3 regulatory region and promotes adhesion. Reduced levels of KLF5 in patient tissue indicate a role in pemphigus vulgaris. Autoantibody fractions from patients impair intercellular adhesion and reduce KLF5 levels in in vitro and in vivo disease models. These effects were dependent on increased activity of histone deacetylase 3, leading to transcriptional repression of KLF5. Inhibiting histone deacetylase 3 increases KLF5 levels and protects against the deleterious effects of autoantibodies in murine and human pemphigus vulgaris models. Together, KLF5 and histone deacetylase 3 are regulators of desmoglein 3 gene expression and intercellular adhesion and represent potential therapeutic targets in pemphigus vulgaris.

Identification of Entinostat as a Novel Modifier of STAT3 Pre-mRNA Alternative Splicing.

Signal transducer and activator of transcription 3 (STAT3) is a pleiotropic factor involved in multiple vital biological processes and a key mediator of gene transcription in response to cytokines, growth factors and aberrant activation of oncogenic signaling. STAT3 has two splicing isoforms, STAT3α and STAT3β, derived from alternative splicing of exon 23 within pre-mRNA. STAT3β differs from STAT3α by replacement of 55 amino-acid residues in the C-terminal transactivation domain with 7 specific amino acids. Thus, a shorter STAT3β was originally regarded as a dominant negative isoform of STAT3α. Recently accumulating evidence from independent studies have shown STAT3 splicing isoforms confer distinct and overlapping functions in many fundamental cellular regulatory steps such as cell differentiation, inflammatory responses, and cancer progression. However, relatively little is known about the mechanisms of STAT3 pre-mRNA splicing, and it remains undiscovered which chemical compounds or bioactive substances can induce the STAT3β expression. In this study, we generated a potent reporter for detection of alternative splicing of STAT3 pre-mRNA optimized for the screening of function-known chemical library, and successfully identified entinostat, a histone deacetylase inhibitor, as a novel inducer of STAT3β through modulating mRNA splicing. Our findings demonstrate that alternative splicing of STAT3 can be regulated by a compound, providing an important clue for understanding the regulation mechanisms of the expression balance of STAT3 isoforms in a chemical biology approach. Entinostat is likely to be a promising seed compound for elucidating how the higher ratio of STAT3β expression impacts on biological responses associated with Janus kinase (JAK)/STAT3 signaling pathway.

Discovery of a Novel Benzimidazole Derivative Targeting Histone Deacetylase to Induce Ferroptosis and Trigger Immunogenic Cell Death.

Ferroptosis is a unique type of cell death, characterized by its reliance on iron dependency and lipid peroxidation (LPO). Consequently, small-molecule ferroptosis modulators have garnered substantial interest as a promising avenue for cancer therapy. Herein, we explored the ferroptosis sensitivity of epigenetic modulators and found that the antiproliferative effects of class I histone deacetylase (HDAC) inhibitors are significantly reliant on ferroptosis. Subsequently, we developed a novel series of HDAC inhibitors, identifying HL-5s with robust inhibitory activity against class I HDACs, particularly HDAC1. Notably, HL-5s induces ferroptosis by augmenting LPO production. Mechanistically, HL-5s increased the YB-1 acetylation and inhibited the Nrf2/HO-1 signaling pathway. Furthermore, HL-5s not only significantly suppresses tumor growth in the PC-9 xenograft model but also remodels the tumor microenvironment in the LLC allograft model. Our study has unveiled that class I HDAC inhibitors can exert antitumor effects by triggering ferroptosis, and HL-5s may serve as a promising candidate for future cancer treatment.

Rapid Affinity and Microsomal Stability Ranking of Crude Mixture Libraries of Histone Deacetylase Inhibitors

Rapid Affinity and Microsomal Stability Ranking of Crude Mixture Libraries of Histone Deacetylase Inhibitors

Analysis of the effect of HDAC inhibitors on the formation of the HIV reservoir.

The HIV reservoir is more dynamic than previously thought with around 70% of the latent reservoir originating from viruses circulating within 1 year of the initiation of antiretroviral therapy (ART). In an ex vivo model system of HIV latency, it was reported that early exposure to class I histone deacetylase (HDAC) inhibitors might prevent these more recently infected cells from entering a state of stable viral latency. This finding raises the possibility that co-administration of HDAC inhibitors at the time of ART initiation may prevent the establishment of much of the HIV reservoir. Here, we tested the effects of the HDAC inhibitors suberoylanilide hydroxamic acid (SAHA) and panobinostat co-administered at the time of ART initiation on the formation of the viral reservoir in HIV-infected humanized mice. As previously shown, SAHA and panobinostat were well tolerated in humanized mice. Unexpectedly, co-administration of SAHA resulted in an increase in the frequency of CD4+ cells carrying HIV DNA but did not alter the frequency of cell-associated HIV RNA in HIV-infected, ART-treated humanized mice. Co-administration of panobinostat did not alter levels of cell-associated HIV DNA or RNA. Our in vivo findings indicate that co-administration of HDAC inhibitors initiated at the same time of ART treatment does not prevent recently infected cells from entering latency.IMPORTANCECurrent antiretroviral therapy (ART) does not eradicate cells harboring replication-competent HIV reservoir. Withdrawal of ART inevitably results in a rapid viremia rebound. The HIV reservoir is more dynamic than previously thought. Early exposure to class I histone deacetylase (HDAC) inhibitors inhibit these more recently infected cells from entering a state of stable viral latency in an ex vivo model of latency, raising the possibility that co-administration of HDAC inhibitors at the time of ART initiation may reduce much of the HIV reservoir. Here, we tested the effects of the HDAC inhibitors suberoylanilide hydroxamic acid or panobinostat during ART initiation on the formation of the viral reservoir in HIV-infected humanized mice. Our in vivo study indicates that in contrast to in vitro observations, the co-administration of HDAC inhibitors at the same time of ART initiation does not prevent recently infected cells from entering latency.

HDAC2-miR183-5p Epigenetic Circuit Contributes to the Growth of Philadelphia Chromosome-Positive B-cell Acute Lymphoblastic Leukemia via PTEN/AKT and c-MYC Signaling Pathway.

Philadelphia chromosome-positive B-cell acute lymphoblastic leukemia (Ph(+)B-ALL) is a hematological malignancy with a poor prognosis. Epigenetic abnormalities, especially abnormal histone acetylation and microRNAs (miRNAs) dysregulation, are a group of epigenetic patterns that contribute to leukemia progression. However, their regulatory mechanisms in Ph(+)B-ALL have not been fully elucidated. In this study, we identified that miR-183-5p is significantly downregulated in Ph(+)B-ALL and associated with poor prognosis. Moreover, we found that the BCR-ABL fusion gene is a key target gene of miR-183-5p. MiR-183-5p directly targets BCR-ABL gene and induces cell apoptosis via PTEN/AKT and c-MYC signaling pathways. In addition, histone deacetylase inhibitor (HADCi) could mitigate the suppressive effects of HDAC2 on miR-183-5p by promoting promoter acetylation, thereby enhancing cell apoptosis. In conclusion, our results indicate that miR-183-5p is a potential biomarker and suggest that a novel "HDAC2-miR-183-5p epigenetic circuitry regulation" may be involved in the pathogenesis of Ph(+)B-ALL. Taken together, These findings provide new insights into the design of promising molecular-targeted drugs for Ph(+)B-ALL.

Phosphatase LHPP confers prostate cancer ferroptosis activation by modulating the AKT-SKP2-ACSL4 pathway

LHPP, a novel, recognized tumor suppressor, exerts a critical influence on the regulation of tumor cell proliferation and survival by modulating various signaling pathways with its phosphatase activity. Here, we unveil a robust correlation between reduced LHPP expression and adverse prognosis in prostate cancer. We demonstrate that LHPP interacts with AKT, thereby dampening AKT phosphorylation and subsequently inhibiting ACSL4 phosphorylation at the T624 site. This interaction impedes phosphorylation-dependent ubiquitination, thwarting SKP2 from recognizing and binding to ACSL4 at the K621 site. As a result, ACSL4 is spared from lysosomal degradation, leading to its accumulation and the promotion of lipid peroxidation, and ferroptosis. Moreover, our findings reveal that Panobinostat, a potent histone-deacetylase inhibitor, intricately regulates LHPP expression at multiple levels through the inhibition of HDAC3. This complex modulation enhances the ferroptosis pathway, offering a novel mechanism for curtailing the growth of prostate tumors and highlighting its significant translational potential for clinical application.

Elevated choline drives KLF5-dominated transcriptional reprogramming to facilitate liver cancer progression.

An increase in the total choline-containing compound content is a common characteristic of cancer cells, and aberrant choline metabolism in cancer is closely associated with malignant progression. However, the potential role of choline-induced global transcriptional changes in cancer cells remains unclear. In this study, we reveal that an elevated choline content facilitates hepatocellular carcinoma (HCC) cell proliferation by reprogramming Krüppel-like factor 5 (KLF5)-dominated core transcriptional regulatory circuitry (CRC). Mechanistically, choline administration leads to elevated S-adenosylmethionine (SAM) levels, inducing the formation of H3K4me1 within the super-enhancer (SE) region of KLF5 and activating its transcription. KLF5, as a key transcription factor (TF) of CRC established by choline, further transactivates downstream genes to facilitate HCC cell cycle progression. Additionally, KLF5 can increase the expression of choline kinase-α (CHKA) and CTP:phosphocholine cytidylyltransferase (CCT) resulting in a positive feedback loop to promote HCC cell proliferation. Notably, the histone deacetylase inhibitor (HDACi) vorinostat (SAHA) significantly suppressed KLF5 expression and liver tumor growth in mice, leading to a prolonged lifespan. In conclusion, these findings highlight the epigenetic regulatory mechanism of the SE-driven key regulatory factor KLF5 conducted by choline metabolism in HCC and suggest a potential therapeutic strategy for HCC patients with high choline content.

Transcriptomic heterogeneity of EGFR-mutant non-small cell lung cancer evolution towards small cell lung cancer.

Histological transformation from epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) to small cell lung cancer (SCLC) is a key mechanism of resistance to EGFR tyrosine kinase inhibitors (TKIs). However, transcriptomic changes between NSCLC and transformed SCLC (t-SCLC) remain unexplored. We conducted whole transcriptome analysis of 59 regions of interest (ROIs) through the spatial profiling of FFPE tissues obtained from ten patients (lung adenocarcinoma, 22; combined SCLC/NSCLC, 7; t-SCLC, 30 ROIs). Transcriptomic profiles and differentially expressed genes (DEGs) were compared between pre- and post-transformed tumors. Following EGFR-TKI treatment, 93.7% (15/16) of transformed-SCLC (t-SCLC) components evolved into neuroendocrine-high subtypes (SCLC-A or SCLC-N). The transition to t-SCLC occurred regardless of EGFR-TKI treatment and EGFR mutational status, with a notable decrease in EGFR expression (P < 0.001) at both mRNA and protein levels. Pathway analysis revealed that gene overexpression was related to epigenetic alterations in t-SCLC. Interestingly, Histone deacetylase (HDAC) inhibitors restored EGFR expression in SNU-2962A cells and their organoid model. The synergistic effects of third-generation EGFR-TKI osimertinib and the HDAC inhibitor fimepinostat were validated in both in vitro and in vivo models. Our study demonstrated most t-SCLC showed neuronal subtypes with low EGFR expression. DEGs analysis and t-SCLC preclinical models identified an epigenetic modifier as a promising treatment strategy for t-SCLC.

Anti-PD-L1 antibody ASC22 in combination with a histone deacetylase inhibitor chidamide as a “shock and kill” strategy for ART-free virological control: a phase II single-arm study

The combination of ASC22, an anti-PD-L1 antibody potentially enhancing HIV-specific immunity and chidamide, a HIV latency reversal agent, may serve as a strategy for antiretroviral therapy-free virological control for HIV. People living with HIV, having achieved virological suppression, were enrolled to receive ASC22 and chidamide treatment in addition to their antiretroviral therapy. Participants were monitored over 24 weeks to measure changes in viral dynamics and the function of HIV-specific CD8+ T cells (NCT05129189). 15 participants completed the study. At week 8, CA HIV RNA levels showed a significant increase from baseline, and the values returned to baseline after discontinuing ASC22 and chidamide. The total HIV DNA was only transiently increased at week 4 (P = 0.014). In contrast, integrated HIV DNA did not significantly differ from baseline. Increases in the proportions of effector memory CD4+ and CD8+ T cells (TEM) were observed from baseline to week 24 (P = 0.034 and P = 0.002, respectively). The combination treatment did not succeed in enhancing the function of HIV Gag/Pol- specific CD8+ T cells. Nevertheless, at week 8, a negative correlation was identified between the proportions of HIV Gag-specific TEM cells and alterations in integrated DNA in the T cell function improved group (P = 0.042 and P = 0.034, respectively). Nine adverse events were solicited, all of which were graded 1 and resolved spontaneously. The combined treatment of ASC22 and chidamide was demonstrated to be well-tolerated and effective in activating latent HIV reservoirs. Further investigations are warranted in the context of analytic treatment interruption.

Molecular docking, ADMET, molecular dynamic simulation, synthesis, and preliminary antiproliferative study of 1,2,4- thiadiazole derivatives as possible histone deacetylase inhibitors

Molecular docking, ADMET, molecular dynamic simulation, synthesis, and preliminary antiproliferative study of 1,2,4- thiadiazole derivatives as possible histone deacetylase inhibitors

Simultaneous inhibition of FLT3 and HDAC by novel 6-ethylpyrazine-2-Carboxamide derivatives provides therapeutic advantages in acute myelocytic leukemia

Synergetic inhibition of FMS-like tyrosine kinase 3 (FLT3) and histone deacetylase (HDAC) by small molecule chimera presents a promising therapeutic approach for acute myeloid leukemia (AML) with FLT3 mutations. In this study, we first observed that the combined use of FLT3 inhibitor gilteritinib and HDAC inhibitor vorinostat increased the survival rate of leukemia xenograft mouse model. Then, we employed a pharmacophore fusion strategy to develop a novel series of FLT3/HDAC dual inhibitors. Among them, compound 25h demonstrated superior inhibitory activity against both FLT3 and HDAC. In particular, compound 25h exhibited enhanced anti-proliferation activity against MOLM-13 cells in comparison to gilteritinib, vorinostat, and their combination, while maintaining reduced cytotoxicity towards normal cells. Mechanistically, the heightened anti-tumor effect of compound 25h was attributed to its more potent regulation of intracellular pathways, notably phosphorylation of ERK, compared to single drug and combination treatments. Furthermore, compound 25h demonstrated superior anti-tumor efficacy in the MOLM-13 xenograft model compared to combination therapy, along with reduced in vivo toxicity. To conclude, we have identified a novel FLT3/HDAC dual inhibitor that could serve as a potential candidate for the treatment of AML.

Discovery of new acetamide derivatives of 5-indole-1,3,4-oxadiazol-2-thiol as inhibitors of HIV-1 Tat-mediated viral transcription.

Human immunodeficiency virus-1 (HIV-1) encodes a transcriptional factor called Tat, which is critical for viral transcription. Tat-mediated transcription is highly ordered apart from the cellular manner; therefore, it is considered a target for developing anti-HIV-1 drugs. However, drugs targeting Tat-mediated viral transcription are not yet available. Our high-throughput screen of a compound library employing a dual-reporter assay identified a 1,3,4-oxadiazole scaffold against Tat and HIV-1 infection. Furthermore, a serial structure-activity relation (SAR) study performed with biological assays found 1,3,4-oxadiazole derivatives (9 and 13) containing indole and acetamide that exhibited potent inhibitory effects on HIV-1 infectivity, with half-maximal effective concentrations (EC50) of 0.17 (9) and 0.24 µM (13), respectively. The prominent derivatives specifically interfered with the viral transcriptional step without targeting other infection step(s) and efficiently inhibited the HIV-1 replication cycle in the T cell lines and peripheral blood mononuclear cells infected with HIV-1. Additionally, compared to the wild type, the compounds exhibited similar potency against anti-retroviral drug-resistant HIV-1 strains. In a series of mode-of-action studies, the compounds inhibited the ejection of histone H3 for facilitating viral transcription on the long-terminal repeat (LTR) promoter. Furthermore, SAHA (a histone deacetylase inhibitor) treatment abolished the compound potency, revealing that the compounds can possibly target Tat-regulated epigenetic modulation of LTR to inhibit viral transcription. Overall, our screening identified novel 1,3,4-oxadiazole compounds that inhibited HIV-1 Tat, and subsequent SAR-based optimization led to the derivatives 9 and 13 development that could be a promising scaffold for developing a new class of therapeutic agents for HIV-1 infection.