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: Increasing detection of low-risk papillary thyroid carcinoma (PTC) is associated with overdiagnosis and overtreatment. N6-methyladenosine (m⁶A)-mediated microRNA (miRNA) dysregulation plays a critical role in tumor metastasis and progression. However, the functional role of m⁶A-miRNAs in PTC remains unclear. This study aims to elucidate the regulatory mechanism of m⁶A-miR-139-5p expression in PTC, determine its association with PTC metastasis, and evaluate its potential as a diagnostic biomarker for PTC metastasis, thereby providing experimental evidence for precision diagnosis and therapy. METHODS: Expression profiles of m⁶A-miRNAs were compared between the The Cancer Genome Atlas (TCGA) and GSE130512 cohorts to identify metastasis-associated candidates. Clinical specimens from 13 metastasis and 18 non-metastasis PTC patients were analyzed to assess m⁶A-miR-139-5p expression and its correlation with metastasis. Functional experiments were conducted to investigate the effect of fat mass and obesity-associated protein (FTO) on pri-miR-139 methylation and processing, clarifying its regulatory role in miR-139-5p expression. In TPC-1 cells, MTT assays were performed to evaluate whether miR-139-5p overexpression could counteract FTO-mediated cell proliferation. Transwell invasion assays were used to determine the impact of miR-139-5p on PTC cell invasion, exploring whether it functions through the ZEB1/E-cadherin axis. RESULTS: By comparing TCGA and GSE130512 cohorts, it was found that circulating m⁶A-miR-139-5p could serve as a biological indicator for detecting PTC metastasis. Detection of 13 metastatic and 18 non-metastatic clinical specimens showed that FTO inhibited the processing of pri-miR-139 by reducing its methylation level, leading to the dysregulation of miR-139-5p in PTC (P<0.05). In TPC-1 cells, MTT assay showed that overexpression of miR-139-5p could partially reverse FTO overexpression-mediated cell proliferation (P<0.05). In addition, miR-139-5p inhibited the invasive ability of PTC cells by targeting the ZEB1/E-cadherin axis, while FTO overexpression could partially weaken this inhibitory effect. CONCLUSIONS Circulating miR-139-5p can be a potential marker for evaluating PTC metastasis. FTO affects the expression and function of miR-139-5p by regulating m⁶A modification of pri-miR-139, but its clinical value needs further verification.
Humans ; MicroRNAs/metabolism* ; Thyroid Cancer, Papillary/metabolism* ; Alpha-Ketoglutarate-Dependent Dioxygenase FTO/metabolism* ; Thyroid Neoplasms/metabolism* ; Cell Line, Tumor ; Neoplasm Metastasis ; Adenosine/genetics* ; Gene Expression Regulation, Neoplastic ; Female ; Male ; Cadherins/metabolism* ; Cell Proliferation ; Zinc Finger E-box-Binding Homeobox 1/genetics*

OBJECTIVES: Bladder cancer is a common malignancy with high incidence and poor prognosis. N⁶-methyladenosine (m⁶A) modification is widely involved in diverse physiological processes, among which the m⁶A recognition protein YTH N⁶-methyladenosine RNA binding protein F2 (YTHDF2) plays a crucial role in bladder cancer progression. This study aims to elucidate the molecular mechanism by which O-linked N-acetylglucosamine (O-GlcNAc) modification of YTHDF2 regulates its downstream target, period circadian regulator 1 (PER1), thereby promoting bladder cancer cell proliferation. METHODS: Expression of YTHDF2 in bladder cancer was predicted using The Cancer Genome Atlas (TCGA). Twenty paired bladder cancer and adjacent normal tissues were collected at the clinical level. Normal bladder epithelial cells (SV-HUC-1) and bladder cancer cell lines (T24, 5637, EJ-1, SW780, BIU-87) were examined by quantitative real-time PCR (RT-qPCR), Western blotting, and immunohistochemistry for expression of YTHDF2, PER1, and proliferation-related proteins [proliferating cell nuclear antigen (PCNA), minichromosome maintenance complex component 2 (MCM2), Cyclin D1]. YTHDF2 was silenced in 5637 and SW780 cells, and cell proliferation was assessed by Cell Counting Kit-8 (CCK-8), colony formation, and EdU assays. Bioinformatics was used to predict glycosylation sites of YTHDF2, and immunoprecipitation (IP) was performed to detect O-GlcNAc modification levels of YTHDF2 in tissues and cells. Bladder cancer cells were treated with DMSO, OSMI-1 (O-GlcNAc inhibitor), or Thiamet G (O-GlcNAc activator), followed by cycloheximide (CHX), to assess YTHDF2 ubiquitination by IP. YTHDF2 knockdown and Thiamet G treatment were further used to evaluate PER1 mRNA stability, PER1 m⁶A modification, and cell proliferation. TCGA was used to predict PER1 expression in tissues; SRAMP predicted potential PER1 m⁶A sites. Methylated RNA immunoprecipitation (MeRIP) assays measured PER1 m⁶A modification. Finally, the effects of knocking down YTHDF2 and PER1 on 5637 and SW780 cell proliferation were assessed. RESULTS: YTHDF2 expression was significantly upregulated in bladder cancer tissues compared with adjacent tissues (mRNA: 2.5-fold; protein: 2-fold), which O-GlcNAc modification levels increased 3.5-fold (P<0.001). YTHDF2 was upregulated in bladder cancer cell lines, and its knockdown suppressed cell viability (P<0.001), downregulated PCNA, MCM2, and CyclinD1 (all P<0.05), reduced colony numbers 3-fold (P<0.01), and inhibited proliferation. YTHDF2 exhibited elevated O-GlcNAc modification in cancer cells. OSMI-1 reduced YTHDF2 protein stability (P<0.01) and enhanced ubiquitination, while Thiamet G exerted opposite effects (P<0.001). Thiamet G reversed the proliferation-suppressive effects of YTHDF2 knockdown, promoting cell proliferation (P<0.01) and upregulating PCNA, MCM2, and CyclinD1 (all P<0.05). Mechanistically, YTHDF2 targeted PER1 via m⁶A recognition, promoting PER1 mRNA degradation. Rescue experiments showed that PER1 knockdown reversed the inhibitory effect of YTHDF2 knockdown on cell proliferation, upregulated PCNA, MCM2, and Cyclin D1 (all P<0.05), and promoted bladder cancer cell proliferation (P<0.001). CONCLUSIONS O-GlcNAc modification YTHDF2 promotes bladder cancer development by downregulating the tumor suppressor gene PER1 through m⁶A-mediated post-transcriptional regulation.
Humans ; Urinary Bladder Neoplasms/metabolism* ; RNA-Binding Proteins/genetics* ; Cell Proliferation ; Cell Line, Tumor ; Disease Progression ; Acetylglucosamine/metabolism* ; Adenosine/metabolism* ; Gene Expression Regulation, Neoplastic ; Genes, Tumor Suppressor

Objective:To investigate the expression of EIF3B and its role in the development of laryngeal carcinoma. Methods:Immunohistochemistry, cell culture, cell transfection, qRT-PCR, Western Blot and other techniques were used to determine the expression difference of EIF3B in laryngeal cancer and adjacent tissues, and analyze the relationship between EIF3B and the size and TNM stage of laryngeal cancer. By constructing a laryngeal carcinoma cell model with EIF3B knocked down, the cell function was studied, and the regulatory effect of EIF3B on laryngeal carcinoma cells was proved in vitro. Finally, the effect of EIF3B on laryngeal carcinoma growth in vivo was studied by subcutaneous xenograft tumor model in nude mice. Results:The signal intensity of EIF3B in laryngeal carcinoma tissues was significantly stronger than that in adjacent tissues, and the expression level of EIF3B was positively correlated with patient age, TNM stage, lymph node metastasis, tumor size and clinical stage. Knocking down EIF3B can significantly inhibit the proliferation, migration and aggregation of cancer cells, and promote apoptosis. In vivo experiments with nude mice also showed that down-regulating EIF3B expression could inhibit tumor formation in vivo. Conclusion:The expression of EIF3B in laryngeal cancer is significantly increased, and it is closely related to the pathological characteristics of laryngeal cancer, which can be used as a diagnostic index of laryngeal cancer. In terms of function, EIF3B knockdown can inhibit the proliferation, migration and tumor formation of laryngeal cancer cells in vitro and in vivo, and may become a candidate target for targeted therapy of laryngeal cancer in the future.
Laryngeal Neoplasms/pathology* ; Humans ; Eukaryotic Initiation Factor-3/metabolism* ; Animals ; Mice, Nude ; Mice ; Cell Line, Tumor ; Cell Proliferation ; Apoptosis ; Cell Movement ; Neoplasm Staging ; Male ; Transfection ; Female ; Middle Aged ; Gene Expression Regulation, Neoplastic

The circadian clock is a highly conserved timekeeping system in organisms, which maintains physiological homeostasis by precisely regulating periodic fluctuations in gene expression. Substantial clinical and experimental evidence has established a close association between circadian rhythm disruption and the development of various malignancies. Research has revealed characteristic alterations in the circadian gene expression profiles in tumor tissues, primarily manifested as a dysfunction of core clock components (particularly circadian locomotor output cycles kaput (CLOCK) and brain and muscle ARNT-like 1 (BMAL1)) and the widespread dysregulation of their downstream target genes. Notably, CLOCK demonstrates non-canonical oncogenic functions, including epigenetic regulation via histone acetyltransferase activity and the circadian-independent modulation of cancer pathways. This review systematically elaborates on the oncogenic mechanisms mediated by CLOCK/BMAL1, encompassing multidimensional effects such as cell cycle control, DNA damage response, metabolic reprogramming, and tumor microenvironment (TME) remodeling. Regarding the therapeutic strategies, we focus on cutting-edge approaches such as chrononutritional interventions, chronopharmacological modulation, and treatment regimen optimization, along with a discussion of future perspectives. The research breakthroughs highlighted in this work not only deepen our understanding of the crucial role of circadian regulation in cancer biology but also provide novel insights for the development of chronotherapeutic oncology, particularly through targeting the non-canonical functions of circadian proteins to develop innovative anti-cancer strategies.
Humans ; ARNTL Transcription Factors/physiology* ; Neoplasms/therapy* ; CLOCK Proteins/physiology* ; Circadian Clocks/genetics* ; Animals ; Circadian Rhythm/genetics* ; Tumor Microenvironment ; Epigenesis, Genetic ; Gene Expression Regulation, Neoplastic

OBJECTIVES: To analyze the association of CHMP2B expression level of with clinicopathological characteristics and prognosis of clear cell renal cell carcinoma (CRCC) and the possible role of CHMP2B in tumorigenesis and progression of CRCC. METHODS: RNAseq data of CRCC were downloaded from the TCGA database for analysis of CHMP2B expression levels in tumor and adjacent tissues and their correlation with clinicopathological characteristics of the patients. Survival outcomes of the patients with high and low CHMP2B expressions were analyzed using the Kaplan-Meier model, and the COX risk regression model was used for identifying the prognostic factors of the patients. The correlation between CHMP2B expression and immune infiltration, its co-expressed genes, and the effect of CHMP2B gene mutations on immunotherapy responses, and its immunohistochemical expression in CRCC and normal tissues were analyzed. Clinical samples of CRCC were collected to examine CHMP2B expressions using RT-PCR, and cell experiment was carried out to test the effect of CHMP2B overexpression on biological behaviors of CRCC cells. RESULTS: CHMP2B was significantly under-expressed in renal cancer tissues, and its overexpression obviously inhibited the proliferation of CRCC cells in vitro. CHMP2B expression level was significantly correlated with age, gender, lymph node metastasis, and tumor stage, and the patients with low CHMP2B expression had poor survival outcomes. Enrichment and co-expression gene analyses suggested that CHMP2B was mainly involved in viral outgrowth, necrotic apoptosis, endocytosis, and immune-regulatory processes in kidney cancer. CONCLUSIONS CHMP2B is lowly expressed in renal cancer tissues to affect tumor progression and tumor immune processes, and may serve as a prognostic biomarker and therapeutic target for CRCC.
Humans ; Carcinoma, Renal Cell/metabolism* ; Kidney Neoplasms/metabolism* ; Cell Proliferation ; Prognosis ; Cell Line, Tumor ; Male ; Female ; Gene Expression Regulation, Neoplastic

OBJECTIVES: To investigate the association of NUF2 expression with tumor prognosis and its regulatory role in tumor microenvironment. METHODS: We analyzed NUF2 expression, its prognostic value, and is immune-related functions across different cancer types using datasets from the Human Protein Atlas (HPA), TCGA, GTEx, CCLE, and TIMER. RT-qPCR, Western blotting, and immunohistochemistry were used to detect NUF2 expression in liver cancer cell lines and tissue and blood samples from patients with liver cancer. GO, KEGG, and GSEA analyses were conducted to explore the molecular mechanisms of NUF2 and its related genes, and a competitive endogenous RNA (ceRNA) network for NUF2 in liver cancer was constructed. RESULTS: NUF2 expression was upregulated in the tumor tissues of 27 cancers and was associated with clinical stages in several cancers. High NUF2 expressions were correlated with poor overall survival, disease-specific survival, progression-free survival, and disease-free survival of cancer patients. NUF2 expression levels were positively correlated with tumor mutational burden, microsatellite instability, infiltrating immune cells, immune cell marker genes and immune checkpoint genes in different cancers. RT-qPCR, Western blotting, and immunohistochemistry confirmed that NUF2 expression was upregulated in liver cancer cell lines and tumor tissues and blood samples of liver cancer patients, and was decreased significantly after operation. GO, KEGG and GSEA analyses indicated that NUF2 was involved in chromosome segregation and cell cycle and was associated with glycine, serine and threonine metabolism. CONCLUSIONS NUF2 expression is upregulated in 27 cancers and is associated with clinical stage and poor prognosis in some malignancies. NUF2 expression is closely correlated with immune cell infiltration in different cancers, suggesting its potential value for predicting immunotherapy response in these cancers.
Humans ; Prognosis ; Immunotherapy ; Tumor Microenvironment ; Liver Neoplasms/metabolism* ; Cell Line, Tumor ; Neoplasms/genetics* ; Gene Expression Regulation, Neoplastic ; Biomarkers, Tumor/genetics*

OBJECTIVES: To explore the association of the expression of WW domain-containing ubiquitin E3 ligase 1 (WWP1) with immune infiltration in tumor microenvironment (TME) of ovarian cancer. METHODS: Ovarian cancer patient data from The Cancer Genome Atlas (TCGA) were used to analyze the association of WWP1 expression with patient prognosis. TISCH2 was utilized to analyze the changes in immune cell subtypes in TME of metastatic tumor and after chemotherapy. The impact of WWP1 on immune cell infiltration, somatic copy number alterations of WWP1 and evolution of immune cell subtypes was evaluated using TIMER and TIGER pseudo-time analysis. A deep learning model was used to analyze TCGA pathological images to investigate the effect of WWP1 on TME of ovarian cancer. RNA-seq analysis was conducted to identify the differentially expressed genes in WWP1-overexpressing SKOV3 cells and validate immune infiltration. Multicolor immunofluorescence assay was used to analyze the immune markers in SKOV3 and SKOV3/DDP cell xenografts in nude mice. RESULTS: The patients with high WWP1 expression levels had significantly lower overall survival rate (P=0.0012). High WWP1 expression levels and Stage IV disease were both associated with a poor prognosis (P<0.05). In metastatic ovarian cancer or after chemotherapy, the percentages of malignant tumor cells and tumor-associated fibroblasts increased in the TME, accompanied by elevated WWP1 levels. WWP1 expression level was positively correlated with pro-tumorigenic immunosuppressive cells (r=0.1323-0.3955, P<0.05) and negatively with tumor-inhibiting immune cells (r=-0.1949- -0.1333, P<0.05). Specific copy number alterations of WWP1 also influenced CD8⁺ T cell percentage and neutrophil infiltration levels in the TME. RNA-seq analysis of WWP1-overexpressing SKOV3 cells and immunofluorescence assay of the tumor-bearing mice yielded findings consistent with those of bioinformatics analysis. CONCLUSIONS WWP1 may serve as a prognostic biomarker and a potential target for immune regulation in the TME of ovarian cancer.
Female ; Ovarian Neoplasms/genetics* ; Humans ; Ubiquitin-Protein Ligases/metabolism* ; Tumor Microenvironment/immunology* ; Animals ; Mice ; Cell Line, Tumor ; Mice, Nude ; Prognosis ; Gene Expression Regulation, Neoplastic

OBJECTIVES: To explore the molecular mechanism by which lncRNA SNHG15 regulates proliferation, invasion and migration of lung adenocarcinoma cells. METHODS: The lncRNA microarray chip dataset GSE196584 and LncBase were used to predict the lncRNAs that interact with miR-30b-3p, and their association with patient prognosis were investigated using online databases, after which lncRNA nucleolar RNA host gene 15 (SNHG15) was selected for further analysis. The subcellular localization of lncRNA SNHG15 and its expression levels in normal human lung epithelial cells and lung adenocarcinoma cell lines were detected using fluorescence in situ hybridization and qRT-PCR. In cultured A549 cells, the changes in cell proliferation, migration, and invasion following transfection with a SNHG15 knockdown plasmid (sh-SNHG15), a miR-30b-3p inhibitor, or their co-transfection were assessed with EdU, wound healing, and Transwell assays. Bioinformatics analyses were used to predict the regulatory relationship between lncRNA SNHG15 and COX6B1, and the results were verified using Western blotting and rescue experiments in A549 cells transfected with sh-SNHG15, a COX6B1-overexpressing plasmid, or both. RESULTS: LncRNA SNHG15 was shown to target miR-30b-3p, and the former was highly expressed in lung adenocarcinoma, and associated with a poor patient prognosis. LncRNA SNHG15 was localized in the cytoplasm and expressed at higher levels in A549 and NCI-H1299 cells than in BEAS-2B cells. In A549 cells, lncRNA SNHG15 knockdown significantly inhibited cell migration, invasion and proliferation, and these changes were reversed by miR-30b-3p inhibitor. A regulatory relationship was found between lncRNA SNHG15 and COX6B1, and their expression levels were positively correlated (r=0.128, P=0.003). MiR-30b-3p knockdown obviously decreased COX6B1 expression in A549 cells, and COX6B1 overexpression rescued the cells from the inhibitory effects of lncRNA-SNHG15 knockdown. CONCLUSIONS LncRNA SNHG15 may compete with COX6B1 to bind miR-30b-3p through a ceRNA mechanism to affect proliferation, migration, and invasion of lung adenocarcinoma cells.
Humans ; MicroRNAs/metabolism* ; RNA, Long Noncoding/genetics* ; Cell Proliferation ; Cell Movement ; Lung Neoplasms/genetics* ; Adenocarcinoma of Lung ; Neoplasm Invasiveness ; A549 Cells ; Adenocarcinoma/genetics* ; Gene Expression Regulation, Neoplastic ; Cell Line, Tumor

OBJECTIVES: To explore the correlation of ELFN1 expression level with prognosis of colorectal cancer and its regulatory role in colorectal cancer cell proliferation and metastasis. METHODS: We analyzed the expression levels of ELFN1 across 33 cancer types using publicly available databases and identified differential genes related to ELFN1 in colorectal cancer. Gene function annotation and enrichment analysis were used to identify the involved signaling pathways. Logistic analysis, Kaplan-Meier analysis and Cox regression analysis were performed to evaluate the correlation between ELFN1 expression and clinicopathological parameters and survival of colorectal cancer patients. qPCR and Western blotting were used to validate the expression levels of ELFN1 in different colorectal cancer cell lines and tissues, and Transwell and EDU experiments were carried out to assess the effect of ELFN1 knockdown on biological behaviors of SW480 cells. RESULTS: ELFN1 was highly expressed in 14 cancers, and its expression was significantly higher in colon cancer tissues than in adjacent tissues. A high expression of ELFN1 mRNA was associated with a poorer overall survival of colorectal cancer patients. Cox regression analysis indicated that ELFN1 expression was an independent prognostic factor for overall survival of the patients. ELFN1 was significantly enriched in tumor metastasis and proliferation and participated in several tumor signaling pathways. The colon cancer cell lines showed significantly higher expression levels of ELFN1 than normal cells, ELFN1 knockdown obviously inhibited proliferation and migration of SW480 cells in vitro. CONCLUSIONS ELFN1 is overexpressed in colorectal cancer and is associated with poor clinical prognosis of the patients. A high ELFN1 expression is associated with malignant phenotypes of colorectal cancer and promotes cancer cell proliferation and metastasis, suggesting its potential as a prognostic biomarker for colorectal cancer.
Humans ; Colorectal Neoplasms/diagnosis* ; Cell Proliferation ; Prognosis ; Cell Line, Tumor ; Biomarkers, Tumor/metabolism* ; Neoplasm Metastasis ; Gene Expression Regulation, Neoplastic ; Nerve Tissue Proteins/metabolism* ; Female ; Male