Endocrine resistance remains a significant therapeutic challenge in estrogen receptor-positive (ER+) breast cancer, the most common subtype, contributing to increased morbidity and mortality. The interaction between ER and HER family receptors, particularly HER2 and epidermal growth factor receptor (EGFR), drives resistance to standard therapies such as tamoxifen and trastuzumab by activating key signaling pathways, including PI3K/AKT and RAS/MAPK. Dysregulated miRNAs, which are non-coding gene expression regulators, have been linked to therapy response.

Drought stress imposes severe challenges on agriculture by impacting crop performance. Understanding drought responses in plants at a cellular level is a crucial first step toward engineering improved drought resilience. However, the molecular responses to drought are complex as they depend on multiple factors, including the severity of drought, the profiled organ, its developmental stage or even the cell types therein. Thus, deciphering the transcriptional responses to drought is especially challenging. In this study, we investigated tissue-specific responses to mild drought (MD) in young Arabidopsis thaliana (Arabidopsis) leaves using single-cell RNA sequencing (scRNA-seq). To preserve transcriptional integrity during cell isolation, we inhibited RNA synthesis using the transcription inhibitor actinomycin D, and demonstrated the benefits of transcriptome fixation for studying mild stress responses at a single-cell level. We present a curated and validated single-cell atlas, comprising 50 797 high-quality cells from almost all known cell types present in the leaf. All cell type annotations were validated with a new library of reporter lines. The curated data are available to the broad community in an intuitive tool and a browsable single-cell atlas (http://www.single-cell.be/plant/leaf-drought). We show that the mesophyll contains two spatially separated cell populations with distinct responses to drought: one enriched in canonical abscisic acid-related drought-responsive genes, and another one enriched in genes involved in iron starvation responses. Our study thus reveals a dual adaptive mechanism of the leaf mesophyll in response to MD and provides a valuable resource for future research on stress responses.

Isorhamnetin (ISO), a dietary flavonoid, has been shown to possess antioxidant, anti-cancer, and anti-inflammatory properties. Cancer-associated fibroblasts (CAFs), found in the tumor microenvironment of several types of cancer including pancreatic ductal adenocarcinoma (PDAC) impact the tumor growth and development of chemoresistance. Thus, modulating CAFs is an attractive mean to increase the efficacy of therapies targeting cancer cells. In this study, the anti-proliferative effect of ISO and the underlying transcriptomic profile of ISO-treated PDAC-derived CAFs were investigated. ISO treatment showed a time- and concentration-dependent decrease in cell viability with a slight increase in apoptotic cells. Microarray and cell cycle analyses revealed ISO induced downregulation of pathways in cell cycle and DNA replication; and G2/M checkpoint. Cell cycle analysis showed cells in the G2/M phase were increased. In response to the treatment, hallmark for p53 pathway genes, known to regulate cell cycle checkpoints, were highly upregulated. Moreover, ISO-treated cells had an increased area of the mitochondrial network, but lower mitochondrial membrane potential accompanied by a decrease of ATP production, measured by oxygen consumption rate. Inflammatory gene expression of IL1A1, IL6, CXCL1, and LIF were significantly inhibited in ISO-treated CAFs. Taken together, our results demonstrated that the cytostatic effect of ISO on human CAFs was mediated by inducing cell cycle arrest at G2/M phase associated with activation of p21, impaired mitochondrial homeostasis, and inhibition of inflammatory mediators gene expression, warranting further investigation for its use in combinatorial therapy that target both the cancer and the tumor microenvironment as a whole.

RNA guanine (G)-quadruplexes (rG4) are unique noncanonical structures composed of stacked guanine quadruplexes that play diverse roles in regulating gene expression, from transcription to protein synthesis. This study proposes a new splice-switching therapy using G-quadruplex-inducing antisense oligonucleotides (G-ASOs) to reinstate dystrophin expression in Duchenne muscular dystrophy (DMD) models. G-ASOs consist of two functionally independent domains that enable the formation of RNA/DNA hetero-G-quadruplex (hG4) structures. The antisense domain binds to complementary sequences within the target RNA, while the G-rich domain, which contains a sequence of continuous guanines (G-tract), interacts with the G-rich region of target RNA to form an hG4 structure. This precise binding forms an hG4 structure that effectively interrupts alternative splicing. In contrast to the traditional methods that block sterically, this technique employs steric hindrance by forming hG4 structures. Significantly, our findings show that hG4 structures can still form effectively even when the G-rich region of the target RNA and the antisense sequence are as much as 70 nucleotides apart. To address the challenges associated with G-quadruplex formation via G-ASO self-assembly, we developed bulge-containing G-ASOs. This enhancement improves both the efficiency of hG4 formation and the induction of exon-skipping therapy. In summary, this study highlights the potential of G-ASOs in gene therapy, specifically DMD, and marks significant progress in the development of novel therapeutic strategies. These findings highlight the effectiveness of G-ASOs in exon-skipping therapy and demonstrate the advancements in RNA structural manipulation.

We performed an integrated analysis of genome-wide DNA methylation and expression datasets in normal cells and healthy animals exposed to polyphenols with estrogenic activity (i.e. phytoestrogens). We identified that phytoestrogens target genes linked to disrupted cellular homeostasis, e.g. genes limiting DNA break repair (RNF169) or promoting ribosomal biogenesis (rDNA). Existing evidence suggests that DNA methylation may be governed by sirtuin 1 (SIRT1) deacetylase via interactions with DNA methylating enzymes, specifically DNMT3B. Since SIRT1 was reported to be regulated by phytoestrogens, we test whether phytoestrogens suppress genes related to disrupted homeostasis via SIRT1/DNMT3B-mediated transcriptional silencing. Human MCF10A mammary epithelial cells were treated with phytoestrogens, pterostilbene (PTS) or genistein (GEN), followed by analysis of cell growth, DNA methylation, gene expression, and SIRT1/DNMT3B binding. SIRT1 occupancy at the selected phytoestrogen-target genes, RNF169 and rDNA, was accompanied by consistent promoter hypermethylation and gene downregulation in response to GEN, but not PTS. GEN-mediated hypermethylation and SIRT1 binding were linked to a robust DNMT3B enrichment at RNF169 and rDNA promoters. This was not observed in cells exposed to PTS, suggesting a distinct mechanism of action. Although both SIRT1 and DNMT3B bind to RNF169 and rDNA promoters upon GEN, the two proteins do not co-occupy the regions. Depletion of SIRT1 abolishes GEN-mediated decrease in rDNA expression, suggesting SIRT1-dependent epigenetic suppression of rDNA by GEN. These findings enhance our understanding of the role of SIRT1-DNMT3B interplay in epigenetic mechanisms mediating the impact of phytoestrogens on cell biology and cellular homeostasis.

Studies have shown that essential oils not only increase cell viability but also affect lipid metabolism in mammals. However, the extent to which these effects are realized in goose liver has not yet been fully elucidated. The object of research is to investigate the effects of four essential oil mixtures (juniper oil, mint oil, thyme oil, rosemary oil) on lipid metabolic gene expressions in goose. We measured mRNA levels of metabolic genes (ACSBG2, ELOVL1, ELOVL2, CYP2Cl9, CYP2K1), antioxidative gene (SOD1) and very low-density lipoprotein triglyceride (VLDL) synthesis genes (APOB, FOXO1, MTTP), in goose (Anser anser) liver. Search groups were formed as C (control; no additives), EK1 (0.4 mL/L essential oil mixture supplemented) and EK2 (0.8 mL/L essential oil mixture supplemented). The relative expression levels of genes in the liver were measured using RT-qPCR. β-Actin was used as reference gene control for normalization of qPCR data. As a result, essential oil supplementation downregulated metabolic genes compared to the control group. APOB gene among VLDL genes was significantly downregulated. Antioxidative effect gene was downregulated in parallel with the others. This indicates that essential oil intake with drinking water downregulates the genes involved in lipid metabolism in goose liver. Our data show that essential oils have a significant effect on the regulation of genes and pathways involved in hepatic lipid metabolism.

Background: Rat models are widely used to study cataracts due to their cost-effectiveness and prominent physiological and genetic similarities to humans The objective of this study was to identify genes involved in cataractogenesis due to galactose exposure in rats. Methods: We analyzed four datasets from the Gene Expression Omnibus, including both ex vivo and in vivo models of cataracts in different rat strains. Feature selection tools were used to identify genes potentially relevant in cataract-related gene expression. A decision tree algorithm was implemented, and its predictions were interpreted using SHAP and LIME. To validate gene expression levels, PCR was conducted on six rat lenses cultured in M199 medium and galactose to induce cataract and six lenses cultured in M199 alone. Results: Using feature selection tools, four key genes-PLAGL2, CMTM7, PCYT1B, and NR1D2-were identified. Only PCYT1B was significantly differentially expressed between the cataract and control groups across analyzed datasets. The model showed strong predictive performance, particularly in ex vivo datasets. SHAP and LIME analyses revealed that CMTM7 had the largest impact on model predictions. PCR results did not show significant differences in gene expression between the cataract and control groups. Conclusion: The decision tree model trained on an in vivo dataset could predict ex vivo and in vivo cataracts despite no significant gene expression differences found between the cataract and control groups. Given a small number of samples, larger studies are needed to validate our findings.

Trigonelline (TGN), an alkaloid identified in medicinal plants such as coffee (Coffea spp.) and fenugreek (Trigonella foenum-graecum), has demonstrated significant anticancer properties across various malignancies, yet its efficacy in bladder cancer (BLCA) remains underappreciated. This study investigates TGN's role in modulating cancer stem cells (CSCs) and the tumor microenvironment (TME), two key contributors to BLCA progression and chemoresistance. Through comprehensive bioinformatics analyses of BLCA patient datasets, a TGY signature (TGFβ3, GLI2, YAP1) was identified as a critical signaling hub associated with poor prognosis, therapeutic resistance, and CSC generation. Computational docking studies revealed TGN's high binding affinity to the TGY signature, TGFβ3 (ΔG = -3.9 kcal/mol), GLI2 (ΔG = -4.2 kcal/mol), YAP1 (ΔG = -3.4 kcal/mol), suggesting its potential to disrupt this signaling axis. In vitro experiments demonstrated that TGN effectively inhibited BLCA cell proliferation, colony formation, and tumorspheroid growth while significantly enhancing cisplatin sensitivity in resistant cell lines. Notably, TGN reduced the transformation of fibroblasts into cancer-associated fibroblasts (CAFs) through the downregulation of α-SMA and FAP (Fibroblast activation protein) expression, indicating its capacity to normalize the TME. Real-time PCR analysis revealed that TGN treatment significantly reduced markers of epithelial-mesenchymal transition and stemness pathways. Our preclinical mouse study demonstrated that combining TGN and cisplatin significantly reduced tumorigenesis in cisplatin-resistant bladder tumoroids harboring CAFs. Importantly, this combination therapy showed no apparent systematic toxicity, suggesting a favorable safety profile. Our findings reveal novel molecular targets of TGN in bladder cancer; TGN acts as a potent disruptor of the TGY signaling axis and a normalizer of the TME by reducing CAF transformation. In sum, our findings advocate for TGN's further exploration as a candidate for combination therapy in drug-resistant BLCA, with the potential to improve patient outcomes by simultaneously targeting both CSCs and the TME, serving as a foundation for future clinical trials.

Oral squamous cell carcinoma (OSCC), one of the most common cancers in Taiwan, needs new therapeutic agents and treatments. The aim of this study was to investigate the anti-proliferative activity of {N-[3-chloro-4-[5-[3-[[[4-[(cyclopropylcarbonyl)-amino]3-(trifluoromethyl)phenylamino]carbonyl]amino]phenyl]-1,2,4-oxadiazol-3-yl]phenyl]-3-pyridine-carboxamide} (COC), a synthetic molecule, in OSCC cells. COC exhibits potent tumor-suppressive efficacy with IC50 values of 195 nM and 204 nM toward SCC2095 and SCC4 OSCC cells, respectively. Our data revealed that COC caused caspase-dependent apoptosis and downregulated the MAPK signaling pathway. In addition, COC modulated the levels of E-cadherin and β-catenin and inhibited migration. COC also decreased p-STAT3 levels, and the overexpression of STAT3 partially attenuated COC-induced cytotoxicity. Therefore, our findings suggest the use of COC as a new approach to oral cancer treatment.

Human T-cell lymphotropic virus type 1 (HTLV-1) infection causes the uncommon and deadly cancer known as adult T-cell leukemia/lymphoma (ATLL), which affects mature T cells. Its clinical appearance is varied, and its prognosis is often miserable. Drug resistance to conventional therapies confers significant therapeutic challenges in the management of ATLL. This review discusses the emerging role of epigenetic medical advances in the treatment of ATLL, focusing on DNA methyltransferase inhibitors, histone deacetylase inhibitors, histone methyltransferase inhibitors, and BET inhibitors. Indeed, several classes of epigenetic therapies currently exhibit trailed efficacy in preclinical and clinical studies: DNA methyltransferase inhibitors like azacitidine and decitabine reexpression of silenced tumor suppressors; histone deacetylase inhibitors like vorinostat and romidepsin induce cell cycle arrest and apoptosis; bromodomain and extra-terminal inhibitors like JQ1 disrupt oncogenic signaling pathways. Whereas preclinical and early clinical data indicate modest to good efficacy for such treatments, significant challenges remain. Here, we discuss the current state of understanding of epigenetic dysregulation in ATLL and appraise the evidence supporting the use of these epi-drugs. However, despite the opened doors of epigenetic treatment, much more research is required with regard to showing the best combinations of drugs and their resistance mechanisms, the minimization of adverse effects, and how this hope will eventually be translated into benefit for the patient with ATLL.

We have previously reported that the serum levels of gut-derived tryptophan metabolite indole-3-propionic acid (IPA) are lower in individuals with liver fibrosis. Now, we explored the transcriptome and DNA methylome associated with serum IPA levels in human liver from obese individuals together with IPA effects on shifting the hepatic stellate cell (HSC) phenotype to inactivation in vitro.

Glucose and insulin positively regulate glycolysis and lipogenesis through the activation of carbohydrate response element-binding protein (ChREBP) and sterol regulatory element-binding protein 1c (SREBP1c), but their respective roles in the regulation of gluconeogenic and ureagenic genes remain unclear. We compared the effects of the insulin antagonist S961 and Chrebp deletion on hepatic glycolytic, lipogenic, gluconeogenic, and ureagenic gene expression in mice. S961 markedly increased the plasma glucose, insulin, and 3-OH-butyrate concentrations and reduced the hepatic triglyceride content, but Chrebp deletion had no additive effect. We subsequently estimated the expression of genes involved in the pathways of glycolysis, gluconeogenesis, and lipogenesis. S961 potently decreased both Chrebp and Srebf1c, but Chrebp deletion weakly decreased Srebf1c mRNA expression. Both the S961 and Chrebp deletion caused decreases in glycolytic (Gck and Pklr) and lipogenic (Fasn, Scd1, Me1, Spot14, Elovl6) gene expression. S961 increased the expression of many gluconeogenic genes (G6pc, Fbp1, Aldob, Slc37a4, Pck), whereas Chrebp deletion reduced the expression of gluconeogenic genes other than Pck1. Finally, we checked the metabolites and gene expression in the ureagenesis pathway. S961 increased ureagenic gene (Arg1, Asl, Ass1, Cps1, Otc) expression, which was consistent with the metabolite data: there were reductions in the concentrations of glutamate and aspartate and increases in those of citrulline, ornithine, urea, and proline. However, Chrebp deletion had no additive effect on ureagenesis. In conclusion, insulin rather than glucose regulate ureagenic gene expression, whereas glucose and insulin regulate gluconegenic gene expression in opposite directions.

Bacteria have a stringent response system mediated by guanosine pentaphosphate and tetraphosphate ((p)ppGpp), which suppresses the expression of genes involved in cell growth and promotes the expression of genes involved in nutrient uptake and metabolism under nutrient-limited stress. In environments with limited availability of iron, an essential trace element, bacteria generally produce and secrete siderophores to efficiently utilize water-insoluble ferric iron (Fe3+) in the environment. In Vibrio parahaemolyticus, Fur (iron-responsive repressor) and RyhB (Fur-regulated small RNA) regulate the expression of genes involved in the utilization of vibrioferrin (VF), a siderophore produced by this bacterium. In this study, we examined whether (p)ppGpp is also involved in regulating the expression of genes related to the VF utilization system. Results of the chrome azurol S plate assay revealed that the strain in which 3 (p)ppGpp synthetases were deleted (∆relA∆spoT∆relV) produced less VF than the parental strain. Growth test results showed that the growth rate of ∆relA∆spoT∆relV in an iron-limited medium was suppressed compared with that of the parental strain but was restored with the addition of VF. Furthermore, RT-quantitative (q)PCR results showed that the expression levels of pvsA (VF biosynthesis gene) and pvuA2 (ferric VF receptor gene) in ∆relA∆spoT∆relV under iron limitation were significantly reduced compared with those in the parental strain. Western blot results demonstrated that the expression level of PvuA2 in ∆relA∆spoT∆relV was lower than that in the parental strain. These results suggest that (p)ppGpp promotes the expression of genes related to VF biosynthesis and the ferric VF uptake system under iron limitation.

Cisplatin causes permanent hearing loss or cisplatin-induced ototoxicity in over 50% of treated patients with cancer, leading to significant social and functional limitations. Interindividual variability in developing hearing loss suggests the role of genetic predispositions to cisplatin-induced hearing loss. We investigated genetic associations between cisplatin-induced ototoxicity and toll-like receptor 4 (TLR4), an immune receptor known to mediate inflammatory responses to cisplatin. Using a case-control candidate gene approach, we identified 20 single nucleotide polymorphisms at the TLR4 locus with significant protection against ototoxicity in a cohort of 213 adult patients, followed by an independent pediatric patient cohort (n = 357). Combined cohort analysis demonstrated a significant association between cisplatin-induced ototoxicity protection and a single variant in the TLR4 promoter, rs10759932. We showed that rs10759932 downregulated TLR4 expression that is normally induced by cisplatin. This work provides pharmacogenetic and functional evidence to implicate TLR4 with cisplatin-induced hearing loss in patients. SIGNIFICANCE STATEMENT: Adult and pediatric patients carrying toll-like receptor 4 (TLR4) genetic variants were protected against developing cisplatin-induced hearing loss following cisplatin treatment. Important variants in the TLR4 promoter disrupted a drug-gene interaction between cisplatin and TLR4, mirroring the protective effect conferred by genetic inhibition of TLR4. These variants have the potential to improve the prediction of cisplatin toxicity, allowing for more precise chemotherapy treatment.

The Hsp90 and Hsp70 chaperones act as a protein quality control system for several hundred client proteins, including many implicated in neurodegenerative disorders. Hsp90 and Hsp70 are widely thought to be important drug targets. Although many structurally distinct compounds have been developed to target Hsp90, relatively few are known to target Hsp70 and even fewer have been tested in protein quality control systems. To address this, we describe a high-throughput thermal shift-based screen to find compounds that bind and stabilize Hsp70 and then employ assays with misfolded forms of a well-established client protein, neuronal NO synthase (nNOS), to identify compounds that enhance ubiquitination of client proteins. The ubiquitination assay employed a quantitative ELISA method to measure Hsp70:CHIP-dependent ubiquitination of heme-deficient nNOS, which is a model of a misfolded client, in reaction mixtures containing purified E1, E2, Hsp70, CHIP, and ubiquitin. We screened 44,447 molecules from the Maybridge and ChemDiv libraries and found one compound, protein folding disease compound 15 (PFD-15), that enhanced in vitro nNOS ubiquitination with an EC50 of approximately 8 μM. PFD-15 was tested in human embryonic kidney 293 cells stably transfected with a C331A nNOS, a mutation that makes nNOS a preferred client protein for ubiquitination. In this model, PFD-15 decreased steady-state levels of C331A nNOS, but not the wild-type nNOS, in a time- and concentration-dependent manner by a process attenuated by lactacystin, an inhibitor to the proteasome. PFD-15 appears to enhance binding of Hsp70 and CHIP to client proteins without interference of protein quality control mechanisms, enabling the selective clearance of misfolded proteins. SIGNIFICANCE STATEMENT: There are few treatment options for neurodegenerative diseases, which are widely thought to be caused by formation of toxic misfolded proteins. One novel approach is to enhance the Hsp90/Hsp70 protein quality control machinery to remove these misfolded proteins. Targeting Hsp70 may have advantages over targeting Hsp90, but fewer compounds targeting Hsp70 have been developed relative to those for Hsp90. The current study provides a novel approach to enhance the number of compounds targeting the Hsp70's role in protein quality control.

Temozolomide (TMZ) is the first-line chemotherapeutic agent for glioblastoma (GBM) therapy; however, resistance to TMZ remains a major obstacle in GBM treatment. The aim of this study is to elucidate the mechanisms underlying TMZ resistance and explore how to enhance the sensitivity of GBM to TMZ.

Cancer-associated fibroblasts (CAFs) have been identified to drive chemotherapy resistance in triple-negative breast cancer (TNBC). This study evaluated the functions of CAFs-mediated suppressive ferroptosis in doxorubicin (DOX) resistance in TNBC and its detailed molecular mechanisms.

Esketamine (EK) has been widely used in the treatment of depression, but the effects of EK prenatal treatment on embryonic heart development have been rarely reported. This study assesses the effects of varying concentrations of EK on embryonic development and cardiogenesis to determine the teratogenic concentration in the zebrafish model, centering on the interaction between the genes nkx2.5 and gata4 to elucidate the mechanisms underlying cardiac morphogenesis. Zebrafish embryos were classified into six distinct groups and exposed to either a vehicle or EK to ascertain the median lethal concentration (LC50) at 48 and 72 h post-fertilization (hpf) analyzing mortality rate data. Embryonic and cardiac morphologies were assessed utilizing live embryo imaging techniques and stereo microscopy. Nkx2.5 and gata4 were identified via whole-mount in situ hybridization (WISH) and reverse transcription quantitative polymerase chain reaction (RT-qPCR). Exposure to EK leads to significant teratogenic effects on zebrafish embryos, which are both concentration- and time-dependent. The 48 h- and 72 h-LC50 of EK for zebrafish embryos were 1.30 (95% CI 0.92, 1.60) millimolar (mM) and 0.71 (95% CI 0.46, 1.01) mM, respectively. A significant reduction in heart rates and body length were observed and the distance between the sinus venosus and bulbar artery (SV-BA) was found expanded, the pericardial edema area showed significant swelling, and the body axis curvature was more pronounced in the EK exposure groups. Both WISH an RT-qPCR analysis showed nkx2.5 staining intensity and expression significantly decreased, while gata4 assay results were in the opposite direction. Our findings indicate that exposure of zebrafish embryos to EK results in embryonic and cardiac malformations, primarily due to the down-regulation of nkx2.5 and the over-expression of gata4. Equilibrium maintenance and compensatory mechanisms are crucial in spatiotemporal gene regulation.

Despite endocrine therapy (ET), approximately 20-40% of Stage I-III estrogen receptor-positive breast cancer (ER + BC) patients experience recurrence. Recurrence while on ET is indicative of ET resistance. This study aimed to identify differentially expressed genes (DEGs) associated with recurrence during ET (ET resistance) and to explore gene expression differences across PAM50 molecular subtypes. Eighty tumor specimens from 79 patients treated at the City of Hope Comprehensive Cancer Center (2012-2016) were analyzed using NanoString technology. Fourteen patients (17.7%) experienced recurrence over a median follow-up of 68 months (range 35-104 months). Key upregulated DEGs in the recurrence group included EZH2 (log2 fold change[log2FC]: 0.67, p = 0.0017), WNT11 (log2FC: 1.08, p = 0.0088), ITGB6 (log2FC: 0.80, p = 0.0312), and TOP2A (log2FC: 0.79, p = 0.0381). Downregulated DEGs included SNAI2 (log2FC: - 0.63, p = 0.0055), ITPR1 (log2FC: - 0.75, p = 0.0083), CD10 (log2FC: - 0.70, p = 0.0092), PTEN (log2FC: - 0.29, p = 0.0163), VRD (log2FC: - 0.46, p = 0.0184), and WNT5A (log2FC: - 0.76, p = 0.0272). EZH2 and TOP2A were positively correlated with proliferation scores, while WNT11 and ITGB6 emerged as potential biomarkers independently associated with recurrence. These findings suggest novel biomarker candidates that could help overcome ET resistance, reduce recurrence, and improve outcomes in ER + BC.

Histone deacetylase (HDAC) inhibitors show promise in treating Burkitt lymphoma (BL), although the precise mechanisms remain unclear. We investigated the effects of valproic acid (VPA), a specific HDAC inhibitor, on BL cell lines RAJI and CA46, focusing on the PTEN/PI3K/AKT pathway. Cell viability, cell cycle progression, and apoptosis were evaluated using the Cell Counting Kit-8 assay and the Annexin V-fluorescein isothiocyanate assay. Chromatin immunoprecipitation sequencing (ChIP-seq) assessed acetylation at the PTEN promoter, while gene expression and protein levels were measured via reverse transcription quantitative polymerase chain reaction and Western blotting, respectively. VPA treatment significantly reduced BL cell viability and induced apoptosis and cell cycle arrest in a dose-dependent manner. Compared to peripheral blood mononuclear cells, BL cells exhibited significantly higher HDAC mRNA and protein levels. ChIP-seq analysis revealed increased acetylation of the PTEN promoter following exposure to VPA. After treatment with 4 mM VPA, PTEN protein levels in BL cells increased significantly, while levels of HDAC, p-AKT, and p-p70S6K proteins decreased markedly. Furthermore, compared to VPA treatment alone, the combination of VPA and the PI3K inhibitor BEZ235 led to even greater PTEN protein expression, further decreased p-AKT and p-p70S6K protein levels, and further reduced cell viability in BL cells. VPA exerts its antitumor effects in BL cells by modulating the PTEN/PI3K/AKT pathway through the inhibition of HDAC1.