Head and neck squamous cell carcinoma （HNSCC） is one of the ten most common cancers worldwide and is one of the refractory cancers with a poor prognosis in otorhinolaryngology-head and neck surgery. Cetuximab is widely used in the clinical treatment of HNSCC and has been approved by the FDA as a first-line chemotherapeutic agent. However, its efficacy varies significantly among different individuals. Therefore, exploring the resistance mechanisms of cetuximab in the treatment of HNSCC and screening for sensitive populations are essential for the precision treatment of head and neck cancer. This article summarizes the research progress on cetuximab resistance mechanisms in HNSCC, and the main aspects include: alterations in epidermal growth factor receptor （EGFR） and its ligands, changes in downstream effectors of EGFR, bypass activation and crosstalk, epithelial-mesenchymal transition, epigenetic modifications, and immunosuppression in the tumor microenvironment.
Humans ; Cetuximab/therapeutic use* ; Drug Resistance, Neoplasm ; Squamous Cell Carcinoma of Head and Neck/drug therapy* ; Head and Neck Neoplasms/drug therapy* ; ErbB Receptors/metabolism* ; Tumor Microenvironment ; Epithelial-Mesenchymal Transition ; Molecular Targeted Therapy ; Antineoplastic Agents, Immunological/therapeutic use*

Objective:The mucosa of Chronic rhinosinusitis with nasal polyps（CRSwNP） is accompanied by tissue remodeling. Epithelial-mesenchymal transition（EMT） plays an important role in tissue remodeling, but the mechanism of EMT is not yet clear. The purpose of this study is to further clarify the pathogenesis of CRSwNP and provide another idea and theoretical basis for the treatment of CRSwNP. Methods:①The expression of NLRP3 and EMT-related protein（E-cadherin, Vimentin） in the nasal mucosa of the CRSwNP group and the normal control group were detected by immunohistochemistry（IHC）. ②Primary human nasal epithelial cells（HNECs） were cultured in vitro, and HNE-intervened cells with different concentrations（0, 10, 25, 50, 100 ng/mL） were used. After stimulation for 24 h, mRNA and protein expressions of E-cadherin, Vimentin, NLRP3 were detected by qRT-PCR and western blotting. ③Cells were collected at 0, 24, 36, 48 and 72 hours later after incubation with HNE with the optimal concentration, and the mRNA and protein expressions of E-cadherin, Vimentin and NLRP3 were detected by qRT-PCR and western blotting. ④Primary human nasal epithelial cells were pretreated with NLRP3 inhibitor MCC950, then stimulated with HNE, and EMT-related proteins（E-cadherin, Vimentin） and NLRP3 expression were detected by qRT-PCR and western blotting. Results:①The expression levels of NLRP3 and Vimentin in nasal polyps of CRSwNP patients were higher than those of control group, and the expression of E-cadherin was lower（P<0.05）. The mRNA and protein expression levels of NLRP3 and Vimentin increased when HNE stimulated primary human nasal epithelial cells, while the expression of E-cadherin decreased. ②The effect was most significant when the HNE stimulated nasal mucosal epithelial cells were exposed to 50 ng/mL（P<0.05）. The primary human nasal epithelial cells were stimulated with 50 ng/ml HNE, and the effect was most significant when the duration of HNE exposure was 36 h（P<0.05）. ③Primary human nasal epithelial cells were pretreated with MCC950 and then stimulated with HNE. The mRNA and protein expression levels of E-cadherin in the NLRP3 inhibitor pretreated group were increased, while the mRNA and protein expression levels of Vimentin and NLRP3 were decreased（P<0.05）. Conclusion:ln CRSwNP, HNE promotes EMT in human nasal mucosal epithelial cells by activating NLRP3.
Humans ; Nasal Polyps/metabolism* ; Epithelial-Mesenchymal Transition ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Sinusitis/metabolism* ; Cadherins/metabolism* ; Vimentin/metabolism* ; Chronic Disease ; Nasal Mucosa/cytology* ; Rhinitis/metabolism* ; Epithelial Cells/metabolism* ; Cells, Cultured ; Rhinosinusitis

OBJECTIVES: To investigate CEACAM6 expression in nasopharyngeal carcinoma (NPC) and its regulatory effects on tumor cell proliferation, migration, and epithelial-mesenchymal transition (EMT). METHODS: CEACAM6 expression in NPC was analyzed using GEO datasets and validated by immunohistochemistry in NPC tissues and by Western blotting and RT-qPCR in NPC cell lines (HNE1, C666-1, HK1, 5-8F and CNE2Z) and normal nasopharyngeal epithelial NP69 cells. In the NPC cell lines, the effects of lentivirus-mediated CEACAM6 overexpression and knockdown on cell proliferation, migration, invasion and cytoskeletal structures were evaluated using CCK-8 assay, Edu staining, wound healing assay, Transwell assay, and phalloidin staining. Western blotting was performed to determine the expressions of EMT-related proteins (FN1, ITGA5, ITGB1, E-cadherin, N-cadherin and vimentin) in the NPC cells and the effect of FN1 overexpression on ITGA5 and ITGB1 protein expressions. RESULTS: Analysis of the data from the GEO datasets suggested that CEACAM6 was significantly downregulated in NPC, which was associated with poor patient prognosis. Immunohistochemistry also showed low expressions of CEACAM6 in clinical NPC tissues (P<0.05). In NPC cells, CEACAM6 overexpression significantly suppressed cell proliferation, migration and invasion and reduced the fluorescence intensity of actin. CEACAM6 overexpression also resulted in significant downregulation of FN1, ITGA5, ITGB1, N-cadherin and vimentin expressions and upregulation of E-cadherin expression, and FN1 overexpression obviously attenuated the inhibitory effect of CEACAM6 overexpression on ITGA5 and ITGB1 expressions. CONCLUSIONS CEACAM6 inhibits NPC cell migration and invasion by inhibiting EMT via regulating FN1, ITGA5 and ITGB1 expressions.
Humans ; Epithelial-Mesenchymal Transition ; Cell Movement ; Cell Proliferation ; Nasopharyngeal Carcinoma ; Nasopharyngeal Neoplasms/metabolism* ; Cell Line, Tumor ; Cell Adhesion Molecules/genetics* ; Antigens, CD/metabolism* ; GPI-Linked Proteins ; Integrin alpha5/metabolism* ; Integrin beta1/metabolism* ; Cadherins/metabolism* ; Fibronectins ; Integrins

OBJECTIVES: To investigate the role of DTX2 in regulating biological behaviors of oxaliplatin-resistant colorectal cancer cells (CRC/OXA cells). METHODS: CCK8 assay was used to determine the inhibition rate of oxaliplatin-treated CRC cells. A CRC/OXA cell line was constructed, in which DTX2 expression level was detected. The cells were transfected with a DTX2-shRNA plasmid or co-transfected with DTX2-shRNA and pcDNA-Notch2, and the changes in cell proliferation, migration and invasion ability were evaluated using plate cloning assay, scratch assay and Transwell invasion assay. The expression levels of Notch2, NICD and epithelial-mesenchymal transition (EMT) proteins of the transfected cells were detected with Western blotting. In a nude mouse model bearing SW620/OXA cell xenografts, the effects of DTX2 knockdown and Notch2 overexpression in the implanted cells on tumor growth and protein expressions were tested. RESULTS: The IC₅₀ of oxaliplatin was 6.00 μmol/L in SW620 cells and 8.00 μmol/L in LoVo cells. CRC/OXA cells showed a significantly increased expression of DTX2. DTX2 knockdown in CRC/OXA cells significantly inhibited cell proliferation, migration and invasion, and these effects were reversed by co-transfection of the cells with pcDNA-Notch2. DTX2 knockdown significantly reduced the expression levels of Notch2, NICD and vimentin proteins and increased E-cadherin expression in CRC/OXA cells, and co-transfection with pcDNA-Notch2 potently attenuated the changes in these proteins. In the tumor-bearing mice, DTX2 overexpression obviously promoted the growth of SW620/OXA cell xenograft, enhanced the protein expressions of Notch2, NICD and vimentin, and lowered the expression of E-cadherin. CONCLUSIONS High expression of DTX2 promotes proliferation, migration, invasion and EMT of CRC/OXA cells through the Notch2 signaling pathway, suggesting the potential of DTX2 as a target to improve the efficacy of oxaliplatin.
Epithelial-Mesenchymal Transition ; Humans ; Cell Proliferation ; Oxaliplatin ; Colorectal Neoplasms/metabolism* ; Animals ; Drug Resistance, Neoplasm ; Receptor, Notch2/metabolism* ; Cell Line, Tumor ; Mice, Nude ; Cell Movement ; Organoplatinum Compounds/pharmacology* ; Neoplasm Invasiveness ; Mice

OBJECTIVES: To investigate the regulatory effects of Aurora-A in regulating proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of cervical cancer cells and the role of actin-related protein 2/3 complex subunit 4 (ARPC4) in mediating its effects. METHODS: The plasmids pCDH-NC, pCDH-Aurora-A, and shRNA-ARPC4 were used for inducing Aurora-A overexpression or ARPC4 knockdown in HeLa cells. The cells were divided into vector group, Aurora-A overexpression group, Aurora-A overexpression+ARPC4 knockdown group, and Aurora-A overexpression+NF‑κBp65 inhibitor group and transfected with the corresponding plasmids. The proliferation, colony-forming ability, migration and invasion of the treated Hela cells was evaluated using EdU immunofluorescence assay, crystal violet staining, scratch assay, Transwell assay, and Matrigel assay. Western blotting was performed to detect the changes in cellular expressions of EMT-related proteins and expression levels of NF-κBp65 and ARPC4. RESULTS: The expression of ARPC4 was significantly decreased in HeLa cells with Aurora-A knockdown and increased in Aurora-A-overexpressing cells. Aurora-A overexpression obviously promoted proliferation, migration, and invasion abilities of HeLa cells, and these effects was significantly antagonized by ARPC4 knockdown. In Aurora-A-overexpressing cells, the phosphorylation level of NF-κBp65 and the expression level of ARPC4 were increased significantly, and application of the NF‑κBp65 inhibitor obviously lowered the expression level of ARPC4. CONCLUSIONS Aurora-A overexpression upregulates the expression of ARPC4 by activating the NF-κBp65 signaling pathway, thereby promoting migration, invasion and EMT of HeLa cells.
Humans ; Uterine Cervical Neoplasms/metabolism* ; Female ; HeLa Cells ; Epithelial-Mesenchymal Transition ; Signal Transduction ; Cell Movement ; Neoplasm Invasiveness ; Cell Proliferation ; Aurora Kinase A/metabolism* ; Transcription Factor RelA/metabolism* ; Neoplasm Metastasis

OBJECTIVES: To investigate the correlation of PRELID1 with gastric cancer (GC) progression, prognosis, and epithelial-mesenchymal transition (EMT) and the underlying mechanisms. METHODS: We analyzed the data of 115 patients undergoing radical gastrectomy for GC in our hospital between February, 2018 and March, 2023 to explore the correlation of PRELID1 expression level in GC tissues with tumor progression and patient prognosis. In cultured GC cells, the effects of lentivirus-mediated overexpression or interference of PRELID1 were observed on cell migration, invasion and EMT. RESULTS: Immunohistochemical staining revealed significantly higher PRELID1 expression in GC tissues (P<0.001), whose expression level was positively correlated with CEA ≥5 ng/mL (P=0.007), CA199 ≥37 U/mL (P=0.007), G_3-4 stages (P=0.001), T_3-4 stages (P=0.001), and N_2-3 stages (P=0.020). Univariate and Cox multifactorial analysis showed that high PRELID1 level was an independent risk factor affecting 5-year survival of GC patients (P=0.001). In cultured GC cells, PRELID1 overexpression obviously promoted cell proliferation, migration, invasion, and the expressions of MMP2 and MMP9, and interference of PRELID1 produced the opposite changes. PRELID1 overexpression also increased the expressions of N-cadherin and vimentin and reduced the expression of E-cadherin. Mechanistic analyses showed that up-regulation of PRELID1 increased the expression of p-PI3K, p-AKT, and p-mTOR in GC cells, whereas its interference caused the opposite changes; the application of 740 Y-P, a PI3K/AKT pathway activator, significantly enhanced the migration, invasion, and EMT of GC cells with PRELID1 knockdown. CONCLUSIONS PRELID1 is highly expressed in GC and affects prognosis of the patients, and its high expression promotes migration, invasion and epithelial mesenchymal transition of GC cells possibly by activating the PI3K/AKT/mTOR pathway.
Humans ; Stomach Neoplasms/metabolism* ; Epithelial-Mesenchymal Transition ; Prognosis ; Cell Movement ; Cell Line, Tumor ; Male ; Female ; Middle Aged ; Signal Transduction ; Neoplasm Invasiveness ; Phosphatidylinositol 3-Kinases/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism*

OBJECTIVES: To investigate the role of circular RNA circ_0000437 in regulating biological behaviors of breast cancer cells and the molecular mechanism. METHODS: Breast cancer MCF-7 and MDA-MB-231 cells were transfected with sh-circ_0000437, mimics, inhibitor, si-CTPS1, or their respective negative controls. qRT-PCR was used to detect the expression levels of circ_0000437, let-7b-5p, CTPS1, Notch1, Hes1, and Numb in breast cancer cell lines and tissues. RNase R digestion was used to confirm the circular structure of circ_0000437 and its subcellular localization in the breast cancer cells was determined by cellular distribution analysis. The changes in proliferation, invasion and migration of the transfected cells were assessed using CCK-8 assay, Transwell assay and scratch assay. Dual-luciferase reporter gene and RNA immunoprecipitation assays were employed to validate binding interactions among circ_0000437, let-7b-5p, and CTPS1. The cellular expressions of CTPS1, E-cadherin, N-cadherin, and vimentin proteins were detected with Western blotting. A tumor-bearing mouse model was used to verify the oncogenic mechanism of circ_0000437 and CTPS1. RESULTS: Circ_0000437 and CTPS1 were upregulated while let-7b-5p was downregulated in breast cancer tissues and cell lines. Circ_0000437 or CTPS1 knockdown obviously suppressed breast cancer cell proliferation, invasion, migration and epithelial-mesenchymal transition (EMT). Overexpression of let-7b-5p produced similar inhibitory effects, whereas inhibition of let-7b-5p significantly enhanced malignant behaviors of the cells. In the tumor-bearing mouse models, circ_0000437 knockdown significantly suppressed tumor growth, but co-transfection of the cells with pcDNA-CTPS1 accelerated tumor growth. Binding sites were identified between circ_0000437 and let-7b-5p and between let-7b-5p and CTPS1, and circ_0000437, let-7b-5p, and CTPS1 showed functional interactions in breast cancer cells. CONCLUSIONS Circ_0000437 is upregulated in breast cancer tissues and cells, and its high expression promotes proliferation, invasion, migration and EMT of breast cancer cells through the let-7b-5p/CTPS1 axis.
Humans ; Epithelial-Mesenchymal Transition ; Cell Proliferation ; MicroRNAs/metabolism* ; RNA, Circular ; Breast Neoplasms/metabolism* ; Cell Movement ; Female ; Neoplasm Invasiveness ; Cell Line, Tumor ; MCF-7 Cells ; Animals ; Mice

OBJECTIVES: To study the impact of SURF4 expression level on long-term prognosis of gastric cancer (GC) and biological behaviors of GC cells. METHODS: SURF4 expression level in GC and its association with long-term patient prognosis were analyzed using publicly available databases and in 155 GC patients with low and high SURF4 expressions detected immunohistochemically. The Cox proportional hazard model and Kaplan-Meier survival curves were used to analyze independent prognostic predictors of GC and the 5-year survival rate of the patients with different SURF4 expression levels. Informatics analyses were conducted to explore the correlation of SURF4 expression level with immune cell infiltration in GC, SURF4-related differential genes and their associated pathways. In cultured GC cell line HGC-27, the effects of SURF4 knockdown and overexpression on proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) were investigated. RESULTS: Analysis of GEPIA dataset and immunohistochemical results suggested significant SURF4 overexpression in GC (P<0.05), which was associated with shortened 5-year survival time of the patients (χ²=38.749, P<0.001). The prognosis of GC was closely related to tumor stage T3-4, N2-3, CEA≥5 μg/L and CA19-9≥37 kU/L (P<0.05). SURF4 expression level was negatively correlated with activated B cells, NK cells and CD8⁺ effector memory T cells (P<0.05) and positively correlated with CD4⁺ T cells (P<0.05). GO and KEGG enrichment analysis suggested that SUFR4 may participate in GC carcinogenesis by promoting EMT through the tight junction pathway. In HGC-27 cells, SURF4 overexpression significantly decreased E-cadherin expression, increased N-cadherin expression, inhibited ZO-1 and claudin-1 expressions, and promoted cell proliferation, migration and invasion. CONCLUSIONS SURF4 is highly expressed in GC, and its overexpression is associated with a shortened 5-year survival of the patients possibly by enhancing tumor cell proliferation, migration and invasion via inhibiting tight junction proteins and promoting EMT.
Humans ; Stomach Neoplasms/metabolism* ; Cell Proliferation ; Cell Movement ; Epithelial-Mesenchymal Transition ; Cell Line, Tumor ; Neoplasm Invasiveness ; Prognosis ; Tight Junction Proteins/metabolism* ; Membrane Proteins/metabolism* ; Female ; Male

OBJECTIVES: To investigate the effect of BRD4 inhibition on migration of esophageal squamous cell carcinoma (ESCC) cells with low acetyl-CoA carboxylase 1 (ACC1) expression. METHODS: ESCC cell lines with lentivirus-mediated ACC1 knockdown or transfected with a negative control sequence (shNC) were treated with DMSO, JQ1 (a BRD4 inhibitor), co-transfection with shNC-siBRD4 or siNC with additional DMSO or C646 (an ahistone acetyltransferase inhibitor) treatment, or JQ1combined with 3-MA (an autophagy inhibitor). BRD4 mRNA expression in the cells was detected using RT-qPCR. The changes in cell proliferation, migration, autophagy, and epithelial-mesenchymal transition (EMT) were examined with CCK8 assay, Transwell migration assay, and Western blotting. RESULTS: ACC1 knockdown did not significantly affect BRD4 expression in the cells but obviously increased their sensitivity to JQ1. JQ1 treatment at 1 and 2 μmol/L significantly inhibited ESCC cell proliferation, while JQ1 at 0.2 and 2 μmol/L promoted cell migration. The cells with ACC1 knockdown and JQ1 treatment showed increased expresisons of vimentin and Slug and decreased expression of E-cadherin. BRD4 knockdown promoted migration of ESCC cells, and co-transfection with shACC1 and siBRD4 resulted in increased vimentin and Slug expressions and decreased E-cadherin expression in the cells. C646 treatment of the co-transfected cells reduced acetylation levels, decreased vimentin and Slug expressions, and increased E-cadherin expression. Treatment with JQ1 alone obviously increased LC3A/B-II levels in the cells either with or without ACC1 knockdown. In the cells with ACC1 knockdown and JQ1 treatment, additional 3-MA treatment significantly decreased the expressions of vimentin, Slug and LC3A/B-II and increased the expression of E-cadherin. CONCLUSIONS BRD4 inhibition promotes autophagy of ESCC cells via a histone acetylation-dependent mechanism, thereby enhancing EMT and ultimately increasing cell migration driven by ACC1 deficiency.
Humans ; Cell Movement ; Transcription Factors/metabolism* ; Esophageal Neoplasms/metabolism* ; Cell Line, Tumor ; Cell Cycle Proteins ; Azepines/pharmacology* ; Epithelial-Mesenchymal Transition ; Carcinoma, Squamous Cell/metabolism* ; Esophageal Squamous Cell Carcinoma ; Triazoles/pharmacology* ; Nuclear Proteins/genetics* ; Cell Proliferation ; Acetyl-CoA Carboxylase/genetics* ; Transfection ; Autophagy ; Bromodomain Containing Proteins

OBJECTIVES: To investigate the oncogenic role of circular RNA circ_EPHB4 in glioma and its molecular mechanism. METHODS: Microarray analysis was performed to identify the differentially expressed circRNAs in glioma tissues. The effects of circ_EPHB4 on glioma cell migration, invasion and epithelial-mesenchymal transition (EMT) in vitro and tumorigenicity in vivo were assessed using scratch wound healing assay, Transwell invasion assay and nude mouse models bearing subcutaneous tumors. RNA immunoprecipitation (RIP), RNA stability assays, and gene overexpression and silencing techniques were employed to validate the synergistic regulatory effect of circ_EPHB4 and the N6-methyladenosine (m⁶A) reader protein YTHDF3 on Wnt3 expression. RESULTS: Circ_EPHB4 was significantly overexpressed by 2.3 folds (|log2FC|=1.2, P<0.01) in glioma tissues compared to the adjacent tissues, and by 2.5 folds in glioma cell line U373 compared to normal cells (P<0.001). Overexpression of circ_EPHB4 significantly enhanced migration and invasion of glioma cells, and promoted the expressions of EMT markers N-cadherin and vimentin. In the tumor-bearing mouse models, the tumor volume in circ_EPHB4 overexpression group was significantly greater than that in the control group, and the lung metastatic foci increased by 4.2 folds. Overexpression of circ_EPHB4 promoted oncogenesis by upregulating Wnt3 expression, while YTHDF3 extended the half-life of Wnt3 mRNA in an m⁶A-dependent manner. Simultaneous knockdown of circ_EPHB4 and YTHDF3 resulted in an obvious reduction of Wnt3 mRNA expression by up to 47% compared to its level following knocking down either circ_EPHB4 or YTHDF3 alone. CONCLUSIONS Circ_EPHB4 and YTHDF3 promote glioma progression by jointly targeting the Wnt3 signaling pathway, which may provide a new therapeutic strategy for gliomas.
Glioma/genetics* ; Humans ; Animals ; Cell Line, Tumor ; RNA-Binding Proteins/genetics* ; RNA, Circular ; Epithelial-Mesenchymal Transition ; Mice, Nude ; Cell Movement ; Wnt3 Protein/genetics* ; Mice ; Disease Progression ; Adenosine/metabolism* ; Brain Neoplasms/metabolism* ; Gene Expression Regulation, Neoplastic