OBJECTIVES: Metastasis is the primary cause of death in osteosarcoma, and current clinical treatments remain limited. BRD4, a key epigenetic regulator, has shown therapeutic promise in various cancers through its inhibition. However, the mechanistic role of BRD4 in osteosarcoma remains poorly understood. This study aims to elucidate the molecular mechanisms by which BRD4 regulate osteosarcoma progression and to explore novel therapeutic strategies. METHODS: Immunofluorescence was used to assess BRD4 expression levels in a tissue microarray containing 80 osteosarcoma samples from different patients. The Gene Expression Omnibus (GEO) dataset (GSE42352, containing survival data from 88 osteosarcoma patients) was downloaded to perform Kaplan-Meier survival analysis based on BRD4 gene expression levels. In vivo, an orthotopic intramedullary osteosarcoma model was established using HOS cells in C57 mice, followed by treatment with varying doses of the BRD4 inhibitor (+)-JQ1. Micro-CT, 3D reconstruction of bone tissue, and HE staining were employed to evaluate pathological changes in bone and intestinal lymph nodes. In vitro, cell viability was measured using the methyl thiazolyl tetrazolium (MTT) assay, while colony formation and Transwell assays assessed proliferative and invasive capacities. Chromatin-bound BRD4 was analyzed via co-immunoprecipitation combined with mass spectrometry (Co-IP/MS), and O-GlcNAc glycosylation sites and glycan chains of BRD4 were identified using Co-IP with Nano-LC MS/MS. Real-time PCR and Western blotting were used to analyze the relative mRNA and protein expression levels of target genes, respectively. RESULTS: BRD4 was positively expressed in 61.25% (49/80) of osteosarcoma tissues. Patients with high BRD4 expression exhibited significantly shorter survival times (P<0.05). In the orthotopic mouse model, intervention with (+)-JQ1, a potent and commonly used BETi, significantly inhibited tumor growth in vivo and reduced bone destruction (P<0.05). (+)-JQ1 treatment significantly suppressed the proliferation (P<0.001), invasion (P<0.001), and migration (P<0.05) of HOS cells. In osteosarcoma cells, BRD4 exhibited O-GlcNAc modifications at both N- and C- C-termini, particularly at Thr73, which is essential for protein stability. This modification also contributed to the activation of the EGFR tyrosine kinase inhibitor resistance pathway (KEGG Pathway: hsa01521). (+)-JQ1 treatment displaced BRD4 from enhancers and downregulated the transcription of pathway-related genes, such as EGFR and PDGFC, thereby suppressing the malignant behavior of osteosarcoma cells. CONCLUSIONS BRD4 promotes osteosarcoma progression via O-GlcNAc modification at Thr73 and plays a crucial role in tumor growth and metastasis.
Osteosarcoma/drug therapy* ; Humans ; Transcription Factors/metabolism* ; Animals ; Cell Cycle Proteins ; Mice ; Bone Neoplasms/drug therapy* ; Azepines/pharmacology* ; Cell Line, Tumor ; Cell Proliferation/drug effects* ; Triazoles/pharmacology* ; Mice, Inbred C57BL ; Nuclear Proteins/metabolism* ; Gene Expression Regulation, Neoplastic ; Male ; Bromodomain Containing Proteins

OBJECTIVES: Pyroptosis plays a critical role in tubulointerstitial lesions of diabetic kidney disease (DKD). Annexin A2 (ANXA2) is involved in cell proliferation, apoptosis, and adhesion and may be closely related to DKD, but its specific mechanism remains unclear. This study aims to investigate the role and molecular mechanism of ANXA2 in high glucose-induced pyroptosis of renal tubular epithelial cells, providing new targets for DKD prevention and treatment. METHODS: Human renal tubular epithelial HK-2 cells were divided into a normal glucose group (5.5 mmol/L), a high glucose group (30.0 mmol/L), and a osmotic control group (24.5 mmol/L mannitol+5.5 mmol/L glucose). ANXA2 expression was modulated by overexpression of plasmids and small interfering RNA (siRNA). Cell proliferation was measured by 5-ethynyl-2'-deoxyuridine (EdU) assay, apoptosis by flow cytometry, and ANXA2, p50, and p65 subcellular localization by immunofluorescence. Western blotting was employed to detect α-smooth muscle actin (α-SMA), fibronectin (FN), and collagen type IV (Col-IV). Real-time fluorescence quantitative PCR (RT-qPCR) and Western blotting were used to analyze nuclear factor-κB (NF-κB) subunits p50/p65 and the pyroptosis pathway factors NLR family Pyrin domain containing 3 (NLRP3), caspase-1, inferleukin (IL)-1β, and IL-18. Protein interactions between ANXA2 and p50/p65 were examined by co-immunoprecipitation, while chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays were used to examine NF-κB binding to the ANXA2 promoter. RESULTS: High glucose upregulated ANXA2 expression and promoted its nuclear translocation (P<0.01). High glucose reduced cell proliferation, increased apoptosis, and elevated α-SMA, FN, and Col-IV expression (all P<0.05); ANXA2 overexpression aggravated these effects (all P<0.05), while ANXA2 knockdown reversed them (all P<0.05). High glucose activated NF-κB and increased NLRP3, caspase-1, L-1β, and IL-18 mRNA and protein expression (all P<0.05); ANXA2 overexpression further enhanced this, whereas knockdown suppressed NF-κB activation and downstream factors (all P<0.05). Co-immunoprecipitation confirmed ANXA2 directly binds the NF-κB subunit p65. ChIP assays revealed p65 binds specifically to ANXA2 promoter regions (ChIP-2, ChIP-4, and ChIP-6), and luciferase activity in corresponding mutant constructs (M2, M4, and M6) was significantly increased versus controls (all P<0.05), confirming positive transcriptional regulation of ANXA2 by p65. CONCLUSIONS ANXA2 and NF-κB form a positive feedback loop that sustains NLRP3 inflammasome activation, promotes pyroptosis pathway activation, and aggravates high glucose-induced renal tubular epithelial cell injury. Targeting ANXA2 or blocking its interaction with p65 may be a novel strategy to slow DKD progression.
Humans ; Pyroptosis/drug effects* ; Annexin A2/physiology* ; Epithelial Cells/cytology* ; Kidney Tubules/cytology* ; Glucose/pharmacology* ; Diabetic Nephropathies/metabolism* ; NF-kappa B/metabolism* ; Cell Line ; Cell Proliferation ; Transcription Factor RelA/metabolism* ; Feedback, Physiological

OBJECTIVES: The core pathology of osteoporosis lies in bone resorption exceeding bone formation; thus, promoting osteogenesis is a key therapeutic strategy. The osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) forms the biological basis of bone formation. Astragaloside IV (A-IV), a major active component of Astragalus membranaceus, is known to enhance osteogenesis, but its precise molecular mechanisms remain unclear. This study aims to investigate the effects of A-IV on the proliferation and osteogenic differentiation of BMSCs from osteoporotic rats and to elucidate its molecular mechanism through the regulation of microRNA-21 (miR-21) and Notch2 expression. METHODS: After 1 week of adaptive feeding, mature female SD rats were randomly divided into a sham-operated (Sham) group (n=4) and an ovariectomized (OVX) group (n=8) to establish an osteoporosis model. Twelve weeks after surgery, BMSCs were isolated from femoral bone marrow and cultured. Cells were divided into a S-BMSCs group (from Sham), an O-BMSCs group (from OVX), and an A-BMSCs group (from OVX-derived BMSCs treated with A-IV). S-BMSCs and O-BMSCs were induced for osteogenic differentiation using osteogenic induction medium, whereas A-BMSCs were treated with A-IV before induction. Flow cytometry was used to identify mesenchymal stem cell surface markers (CD29) and hematopoietic stem cell marker (CD34) to confirm BMSC characteristics. Cell proliferation was assessed using the methyl thiazolyl tetrazolium (MTT) assay. Alizarin red staining was performed to quantify calcium nodule formation, and alkaline phosphatase (ALP) activity assays were used to evaluate osteogenic differentiation. Real-time reverse transcription PCR (real-time RT-PCR) was used to detect changes in osteogenic-related genes, runt-related transcription factor 2 (Runx2) and osteopontin (OPN), as well as miR-21 expression. Western blotting was performed to assess Runx2, OPN, and Notch2 protein expression. RESULTS: Flow cytometry confirmed that O-BMSCs retained the phenotypic characteristics of mesenchymal stem cells. A-IV significantly enhanced the proliferation of BMSCs from osteoporotic rats (P<0.05), increased ALP activity, and upregulated the mRNA and protein expression of Runx2 and OPN (P<0.05). Bioinformatic and experimental analyses demonstrated that miR-21 directly targeted Notch2. A-IV treatment increased miR-21 expression while suppressing Notch2 protein expression and inhibiting activation of the Notch signaling pathway (P<0.05). CONCLUSIONS Astragaloside IV promotes the osteogenic differentiation of BMSCs derived from osteoporotic rats by upregulating miR-21 expression and inhibiting the key Notch signaling protein Notch2, thereby relieving the Notch2-mediated suppression of osteogenesis.
Animals ; Triterpenes/pharmacology* ; Saponins/pharmacology* ; Osteogenesis/drug effects* ; MicroRNAs/metabolism* ; Rats, Sprague-Dawley ; Female ; Cell Differentiation/drug effects* ; Mesenchymal Stem Cells/drug effects* ; Signal Transduction/drug effects* ; Osteoporosis/pathology* ; Rats ; Cells, Cultured ; Receptor, Notch2/metabolism* ; Receptors, Notch/metabolism* ; Ovariectomy ; Cell Proliferation/drug effects*

Retinopathy of prematurity (ROP) is a vision-threatening disorder that leads to pathological growth of the retinal vasculature due to hypoxia. Here, we investigated the potential effects of alamandine, a novel heptapeptide in the renin-angiotensin system (RAS), on hypoxia-induced retinal neovascularization and its underlying mechanisms. In vivo, the C57BL/6J mice with oxygen-induced retinopathy (OIR) were injected intravitreally with alamandine (1.0 μmol/kg per eye). In vitro, human retinal microvascular endothelial cells (HRMECs) were utilized to investigate the effects of alamandine (10 μg/mL) on proliferation, apoptosis, migration, and tubular formation under vascular endothelial growth factor (VEGF) stimulation. Single-cell RNA sequencing (scRNA-seq) matrix data from the Gene Expression Omnibus (GEO) database and RAS-related genes from the Molecular Signatures Database (MSigDB) were sourced for subsequent analyses. By integrating scRNA-seq data across multiple species, we identified that RAS-associated endothelial cell populations were highly related to retinal neovascularization. The liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis revealed a significant decrease in alamandine levels in both the serum and retina of OIR mice compared to those in the control group. Next, alamandine ameliorated hypoxia-induced retinal pathological neovascularization and physiologic revascularization in OIR mice. In vitro, alamandine effectively mitigated VEGF-induced proliferation, scratch wound healing, and tube formation of HRMECs primarily by inhibiting the hypoxia-inducible factor-1α (HIF-1α)/VEGF pathway. Further, coincubation with D-Pro⁷ (Mas-related G protein-coupled receptor D (MrgD) antagonist) hindered the beneficial impacts of alamandine on hypoxia-induced pathological angiogenesis both in vivo and in vitro. Our findings suggested that alamandine could mitigate retinal neovascularization by targeting the MrgD-mediated HIF-1α/VEGF pathway, providing a potential therapeutic agent for OIR prevention and treatment.
Animals ; Retinal Neovascularization/prevention & control* ; Mice, Inbred C57BL ; Vascular Endothelial Growth Factor A/metabolism* ; Humans ; Mice ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Oligopeptides/therapeutic use* ; Signal Transduction/drug effects* ; Cell Proliferation/drug effects* ; Endothelial Cells/drug effects* ; Retinopathy of Prematurity/drug therapy* ; Apoptosis/drug effects* ; Cell Movement/drug effects* ; Renin-Angiotensin System/drug effects* ; Cells, Cultured

OBJECTIVES: To explore the mechanism by which histone deacetylase 1 (HDAC1) regulates steroid-induced apoptosis of mouse osteocyte-like MLO-Y4 cells. METHODS: MLY-O4 cells were treated with 400 nmol/L trichostatin A (TSA) or 1 mmol/L dexamethasone for 24 h or transfected with a HDAC1-overexpressing vector prior to TSA or dexamethasone treatment. The changes in the expressions of HDAC1, SP1, cleaved caspase-3 and Bax, SP1 acetylation level, cell proliferation, and cell apoptosis were examined. The interaction between HDAC1 and SP1 was determined with immunoprecipitation assay and Western blotting. RESULTS: Treatment with dexamethasone significantly increased cell apoptosis, enhanced the expressions of cleaved caspase-3 and Bax, reduced HDAC1 expression, and suppressed proliferation of MLO-Y4 cells. Both TSA and dexamethasone obviously increased SP1 acetylation level and the expression of SP1 in MLO-Y4 cells. HDAC1 overexpression in the cells significantly attenuated the effect of TSA and dexamethasone, promoted cell proliferation, lowered the expressions of SP1, cleaved caspase-3 and Bax, and inhibited dexamethasone-induced cell apoptosis. Immunoprecipitation assay and Western blotting demonstrated the interaction between HDAC1 and SP1 in the cells. CONCLUSIONS HDAC1 inhibits dexamethasone-induced apoptosis and promotes proliferation of cultured mouse osteocytes by suppressing SP1 expression via promoting its deacetylation.
Animals ; Apoptosis/drug effects* ; Mice ; Histone Deacetylase 1/genetics* ; Osteocytes/drug effects* ; Sp1 Transcription Factor/metabolism* ; Acetylation ; Dexamethasone/pharmacology* ; Cell Proliferation/drug effects* ; Caspase 3/metabolism* ; Cell Line ; Hydroxamic Acids/pharmacology* ; bcl-2-Associated X Protein/metabolism*

OBJECTIVES: To investigate the active ingredients in Hedyotis diffusa-Scutellaria barbata D. Don and the main biological processes and signaling pathways mediating their inhibitory effect on primary hepatocellular carcinoma (HCC). METHODS: The core intersecting genes of HCC and the two drugs were screened from TCMSP, Uniport, Genecards, and String databases using Cytoscape software, and GO and KEGG enrichment analyses of the intersecting genes were conducted. Molecular docking between the active ingredients of the drugs and the core genes was carried out using Pubcham, RCSB and Autoduckto to identify the active ingredients with the highest binding energy, whose inhibitory effect on HepG2 cells was verifies using CCK-8 assay, flow cytometry and Western blotting. RESULTS: TP53 and ESR1 were identified as the core genes of HCC and the two drugs. GO and KEGG analyses showed that the two genes were mainly involved in regulation of apoptotic signaling pathway, cell population proliferation, methane raft, and protein kinase activity, and participated in the signaling pathways of apoptosis, proteoglycans in cancer, PI3K Akt signaling pathway, and hepatitis B. Molecular docking studies showed that the active ingredients of the drugs could be docked with TP53 and ESR1 genes under natural conditions, and ursolic acid had the highest binding energy to ESR1 (-4.98 kcal/mol). The results of CCK-8 assay, flow cytometry and Western blotting all demonstrated significant inhibitory effect of ursolic acid on HepG2 cells. CONCLUSIONS The inhibitory effect of Hedyotis diffusa-scutellariae barbatae on HCC is mediated by multiple active ingredients in the two drugs.
Humans ; Molecular Docking Simulation ; Liver Neoplasms/drug therapy* ; Hep G2 Cells ; Network Pharmacology ; Carcinoma, Hepatocellular/drug therapy* ; Hedyotis/chemistry* ; Signal Transduction/drug effects* ; Cell Proliferation/drug effects* ; Tumor Suppressor Protein p53/metabolism* ; Apoptosis/drug effects* ; Estrogen Receptor alpha/metabolism* ; Drugs, Chinese Herbal/pharmacology*

OBJECTIVES: To investigate the effects of dihydroartemisinin (DHA) combined with doxorubicin (DOX) on proliferation and apoptosis of triple-negative breast cancer cells and explore the underlying molecular mechanism. METHODS: MDA-MB-231 cells were treated with 50, 100 or 150 μmol/L DHA, 0.5 μmol/L DOX, or with 50 μmol/L DHA combined with 0.5 μmol/L DOX. The changes in proliferation and survival of the treated cells were examined with MTT assay and colony-forming assay, and cell apoptosis was analyzed with flow cytometry. Western blotting was performed to detect the changes in protein expression levels of PCNA, cleaved PARP, Bcl-2, Bax, STAT3, p-STAT3, HIF-1α and survivin. RESULTS: The IC₅₀ of DHA was 131.37±29.87 μmol/L in MDA-MB-231 cells. The cells with the combined treatment with DHA and DOX showed significant suppression of cell proliferation. Treatment with DHA alone induced apoptosis of MDA-MB-231 cells in a dose-dependent manner, but the combined treatment produced a much stronger apoptosis-inducing effect than both DHA and DOX alone. DHA at 150 μmol/L significantly inhibited clone formation of MDA-MB-231 cells, markedly reduced cellular expression levels of PCNA, p-STAT3, HIF-1α and survivin proteins, and obviously increased the expression level of cleaved PARP protein and the Bax/Bcl-2 ratio, and the combined treatment further reduced the expression level of p-STAT3 protein and increased the Bax/Bcl-2 ratio. CONCLUSIONS DHA combined with DOX produces significantly enhanced effects for inhibiting cell proliferation and inducing apoptosis in MDA-MB-231 cells possibly as result of DHA-mediated negative regulation of the STAT3/HIF-1α pathway.
Humans ; STAT3 Transcription Factor/metabolism* ; Apoptosis/drug effects* ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Doxorubicin/pharmacology* ; Triple Negative Breast Neoplasms/metabolism* ; Cell Line, Tumor ; Artemisinins/pharmacology* ; Female ; Cell Proliferation/drug effects* ; Signal Transduction/drug effects* ; Survivin

OBJECTIVES: To identify potential molecular targets of quercetin in the treatment of clear cell renal carcinoma (ccRCC). METHODS: The therapeutic targets of quercetin were screened from multiple databases by network pharmacology analysis, and the targets significantly correlated with ccRCC were screened from 4907 plasma proteins using a Mendelian randomization method. The drug-disease network model was constructed to screen the potential key targets. The functions of these targets were evaluated via bioinformatics analysis, and the screened targets were verified in cultured ccRCC cells. RESULTS: Network pharmacology analysis combined with Mendelian randomization identified TP53 (OR=3.325, 95% CI: 1.805-6.124, P=0.0001), ARF4 (OR=0.173, 95% CI: 0.065-0.456, P=0.0003), and DPP4 (OR=0.463, 95% CI: 0.302-0.711, P=0.0004) as the core targets in quercetin treatment of ccRCC. Bioinformatics analysis showed that TP53 was highly expressed in ccRCC, and patients with high TP53 expressions had worse survival outcomes. Molecular docking studies showed that the binding energy between quercetin and TP53 was -5.83 kcal/mol. In cultured 786-O cells, CCK-8 assay and wound healing assay showed that treatment with quercetin significantly inhibited cell proliferation and migration. Quercetin treatment also strongly suppressed the expression of TP53 at both the mRNA and protein levels in 786-O cells as shown by RT-qPCR and Western blotting. CONCLUSIONS TP53 may be the key target of quercetin in the treatment of ccRCC, which sheds light on potential molecular mechanism that mediate the therapeutic effect of quercetin.
Humans ; Quercetin/pharmacology* ; Carcinoma, Renal Cell/genetics* ; Cell Proliferation/drug effects* ; Kidney Neoplasms/genetics* ; Cell Movement/drug effects* ; Tumor Suppressor Protein p53/metabolism* ; Cell Line, Tumor ; Computational Biology

OBJECTIVES: To investigate the effect of curcumin on lipid metabolism in non-small cell lung cancer (NSCLC) and its molecular mechanism. METHODS: The inhibitory effect of curcumin (0-70 μmol/L) on proliferation of A549 and H1299 cells was assessed using MTT assay, and 20 and 40 μmol/L curcumin was used in the subsequent experiments. The effect of curcumin on lipid metabolism was evaluated using cellular uptake assay, wound healing assay, triglyceride (TG)/free fatty acid (NEFA) measurements, and Oil Red O staining. Western blotting was performed to detect the expressions of PGC-1α, PPAR-α, and HIF-1α in curcumin-treated cells. Network pharmacology was used to predict the metabolic pathways, and the results were validated by Western blotting. In a nude mouse model bearing A549 cell xenograft, the effects of curcumin (20 mg/kg) on tumor growth and lipid metabolism were assessed by measuring tumor weight and observing the changes in intracellular lipid droplets. RESULTS: Curcumin concentration-dependently inhibited the proliferation of A549 and H1299 cells and significantly reduced TG and NEFA levels and intracellular lipid droplets. Western blotting revealed that curcumin significantly upregulated PGC-1α and PPAR‑α expressions in the cells. KEGG pathway enrichment analysis predicted significant involvement of the HIF-1 signaling pathway in curcumin-treated NSCLC, suggesting a potential interaction between HIF-1α and PPAR‑α. Western blotting confirmed that curcumin downregulated the expression of HIF-1α. In the tumor-bearing mice, curcumin treatment caused significant reduction of the tumor weight and the number of lipid droplets in the tumor cells. CONCLUSIONS Curcumin inhibits NSCLC cell proliferation and lipid metabolism by downregulating the HIF-1α pathway.
Curcumin/pharmacology* ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Animals ; Lipid Metabolism/drug effects* ; Carcinoma, Non-Small-Cell Lung/pathology* ; Lung Neoplasms/pathology* ; Mice, Nude ; Down-Regulation ; Mice ; Cell Proliferation/drug effects* ; Cell Line, Tumor ; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha ; PPAR alpha/metabolism* ; Signal Transduction/drug effects* ; A549 Cells

OBJECTIVES: To investigate the inhibitory effect of Fuzheng Huaji Decoction against non-small cell lung cancer (NSCLC) cells in vitro and explore the underlying mechanism. METHODS: The active ingredients and targets of Fuzheng Huaji Decoction were identified using TCMSP and SwissTargetPrediction databases. NSCLC-related targets from GeneCards and PharmGKB were intersected with the targets of the Decoction, and a protein-protein interaction (PPI) network was constructed to identify the core targets, which were analyzed with GO and KEGG pathway enrichment analysis. Cultured A549 cells were treated with different concentrations of Fuzheng Huaji Decoction-medicated serum, and the changes in cell proliferation, apoptosis, and protein expressions were examined using CCK-8 assay, annexin V-FITC/PI staining and Western blotting. RESULTS: Fuzheng Huaji Decoction contained 140 active ingredients, and 707 drug-disease intersecting targets were identified. Among these targets, TP53, AKT1, HIF1A, GAPDH, ALB, EGFR, CTNNB1, and TNF were identified as the core targets which were involved in the biological processes related to kinases and receptors and the PI3K-AKT, Ras, calcium, and MAPK pathways. Molecular docking studies indicated strong binding affinity of the active ingredients with TP53, AKT1, and HIF1A. In cultured A549 cells, treatment with 2.5%, 5%, and 10% Fuzheng Huaji Decoction-medicated serum significantly inhibited cell proliferation, promoted cell apoptosis, and downregulated the expression levels of HIF1A, p-AKT (Thr308), and TP53 proteins. CONCLUSIONS Fuzheng Huaji Decoction inhibits proliferation of NSCLC cells possibly by downregulating the expressions of HIF1A, p-AKT (Thr308), and TP53.
Humans ; Carcinoma, Non-Small-Cell Lung/metabolism* ; Drugs, Chinese Herbal/pharmacology* ; Cell Proliferation/drug effects* ; Apoptosis/drug effects* ; Lung Neoplasms/metabolism* ; A549 Cells ; Proto-Oncogene Proteins c-akt/metabolism* ; Protein Interaction Maps ; Signal Transduction/drug effects* ; Cell Line, Tumor