Invasion Of Oral Squamous Cell Carcinoma Cells Research Articles

Sevoflurane inhibits oral squamous carcinoma progression by modulating the circ_0000857/miR-145-5p axis.

Oral squamous cell carcinoma (OSCC) is a kind of oral malignant tumor with the highest incidence. This study investigated whether sevoflurane (SEV) inhibited OSCC cell progression by regulating circular RNA_0000857 (circ_0000857). OSCC cells were anesthetized with SEV at different concentrations. The expression of circ_0000857 and microRNA-145-5p (miR-145-5p) were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability was assayed by the Cell Counting Kit-8 (CCK-8), and cell migration and invasion were examined by the wound-healing assay and transwell. Tube formation assay detected angiogenesis. Western blot was used to detect the expression of related proteins. Compared with the control group, SEV inhibited OSCC cell migration, invasion, and angiogenesis. SEV treatment significantly decreased circ_0000857 expression level, but increased miR-145-5p expression level in SCC4 and HSC3 cells. MiR-145-5p was a target of circ_0000857, and miR-145-5p inhibitor reversed the suppressing effects mediated by circ_0000857 silencing on OSCC cell migration, invasion, and angiogenesis. SEV inhibited the level of matrix metalloproteinases 2 (MMP2), MMP9, and vascular endothelial growth factor A (VEGFA) protein by regulating the circ_0000857/miR-145-5p axis. In all, SEV regulated the migration, invasion, and angiogenesis of OSCC cells through the circ_0000857/miR-145-5p axis, which provided a basis for the potential role of SEV in the treatment of OSCC.

A Method by which circUBR1 Controls the Proliferation, Migration, and Invasion of HSC3 Cells

This work investigates the effects of circUBR1 and the underlying mechanisms on the growth, migration and penetration of HSC3 cells derived from oral squamous carcinoma. The expression levels of circUBR1, miR-216a-3p and HSC3 were assessed in tissues from oral squamous cell carcinoma (OSCC) and adjacent tissues.
 Based on the transfection targets, the cells were divided into four groups: si-NC, si-circUBR1, miR-NC, miR-216a-3p, si-circUBR1+anti-miR-NC and si-circUBR1+anti-miR-216a-3p. The cell viability, scratch healing rate, MMP-2 and MMP-9 expression, number of cell clones formed, and number of invasion cells were significantly lower in the miR-216a-3p group compared to the miR-NC group (p<0.05).
 Moreover, when comparing the si-circUBR1+anti-miR-NC group to the si-circUBR1+anti-miR-216a-3p group, the cell viability, scratch healing rate, MMP-2 and MMP-9 expression, number of cell clones formed, and number of invasion cells were significantly higher in the si-circUBR1+anti-miR-216a-3p group (p<0.05). This suggests that disrupting circUBR1 expression leads to up-regulation of miR-216a-3p, resulting in reduced proliferation, clone formation, migration, and invasion of OSCC cells.

THBS1-Mediated Degradation of Collagen via the PI3K/AKT Pathway Facilitates the Metastasis and Poor Prognosis of OSCC.

Oral squamous cell carcinoma (OSCC) is a prevalent form of malignant tumor, characterized by a persistently high incidence and mortality rate. The extracellular matrix (ECM) plays a crucial role in the initiation, progression, and diverse biological behaviors of OSCC, facilitated by mechanisms such as providing structural support, promoting cell migration and invasion, regulating cell morphology, and modulating signal transduction. This study investigated the involvement of ECM-related genes, particularly THBS1, in the prognosis and cellular behavior of OSCC. The analysis of ECM-related gene data from OSCC samples identified 165 differentially expressed genes forming two clusters with distinct prognostic outcomes. Seventeen ECM-related genes showed a significant correlation with survival. Experimental methods were employed to demonstrate the impact of THBS1 on proliferation, migration, invasion, and ECM degradation in OSCC cells. A risk-prediction model utilizing four differentially prognostic genes demonstrated significant predictive value in overall survival. THBS1 exhibited enrichment of the PI3K/AKT pathway, indicating its potential role in modulating OSCC. In conclusion, this study observed and verified that ECM-related genes, particularly THBS1, have the potential to influence the prognosis, biological behavior, and immunotherapy of OSCC. These findings hold significant implications for enhancing survival outcomes and providing guidance for precise treatment of OSCC.

TRIM32 promotes oral squamous cell carcinoma progression by enhancing FBP2 ubiquitination and degradation

The aberrant expression of TRIM32, an E3 ubiquitin ligase, has been identified in multiple malignant cancer types. Nevertheless, the functional roles and detailed mechanisms of TRIM32 in oral squamous cell carcinoma (OSCC) remain to be elucidated. Here, we investigated TRIM32 expression and its functional role in OSCC. TRIM32 expression was consistently elevated in OSCC tissues, particularly in samples from patients with advanced clinical grades. Functionally, silencing TRIM32 dampened OSCC cell growth, migration and invasion. Additionally, a xenograft tumor model suggested that TRIM32 knockdown suppressed in vivo OSCC tumor growth and lung metastasis formation. Mechanistically, we discovered that TRIM32 directly bound to the FBP2 protein via mass spectrometry and co-immunoprecipitation. TRIM32 could interact with FBP2 and accelerates its degradation, eventually enhancing glycolysis in OSCC cell lines. Importantly, rescue assays demonstrated that FBP2 silencing could at least partially offset the tumor-suppressive and aerobic glycolysis inhibition effect induced by TRIM32 knockdown. Thus, our findings demonstrate that TRIM32 plays a crucial role in promoting tumor growth and enhancing glycolysis through FBP2 inhibition. Given OSCC is associated with increased glycolysis levels, our study suggests potential therapeutic targets for OSCC treatment.

A novel long noncoding RNA located on the antisense strand of MAL promotes the invasion and metastasis of oral squamous cell carcinoma

ObjectivesThis study aims to investigate the role of the long non-coding RNA-AC103563.8 (lncRNA) in promoting oral squamous cell carcinoma (OSCC) development and to conduct preliminary research on its mechanism. DesignMicroarray technology were used to screen out a lncRNA significantly upregulated in OSCC. Fluorescence in situ hybridization was used to analyze the position of lncRNA-AC103563.8 in cells. A Cal-27 cell line with knockout of the lncRNA-AC103563.8 gene was constructed. Transwell assay and tumor xenograft experiment was used to determine the metastasis and invasion of the cell. Detection of mutations in genes encoding myelin and lymphocyte proteins (MAL) by pyrosequencing. Identification of RNA-Binding Proteins by Mass Spectrometry (ChIRP-MS) experiments were carried out to enrich the proteins that directly bind to lncRNA-AC103563.8. Bioinformatics was used to analyze the target proteins. Some of the selected proteins were verified by parallel reaction monitoring (PRM) to confirm their binding to lncRNA-AC103563.8. ResultslncRNA-AC103563.8 is upregulated in OSCC tissue and the presence of lncRNA-AC103563.8 in both the nucleus and the cytoplasm. lncRNA-AC103563.8 promoted OSCC cell invasion and metastasis. Methylation occurs in MAL gene promoter. ChIRP-MS identified 330 proteins binding to lncRNA-AC103563.8, and bioinformatics analysis showed that they were involved in a variety of biological processes. PRM experiments confirmed some protein directly bound to lncRNA-AC103563.8. ConclusionlncRNA-AC103563.8 is a functional lncRNA that promotes OSCC development by acting on MAL or interacting with other tumor-related proteins. This study also indicates that this lncRNA may exert regulatory functions in OSCC and is a potential target for OSCC therapy.

CircLDLRAD3 inhibits Oral squamous cell carcinoma progression by regulating miR-558/Smad4/TGF-β.

Oral squamous cell carcinoma (OSCC) is a malignant neoplasm with high mortality and morbidity. The role of circRNA and its molecular mechanism in OSCC remains largely unknown. The study aims to explore the role of a novel circular RNA (circLDLRAD3) in OSCC and its underlying mechanism. PCR and fluorescence in situ hybridization were used to explore the expression features of circLDLRAD3 in OSCC. The effects of circLDLRAD3 on the behaviour of OSCC were investigated using CCK-8, colony formation assay, transwell and animal experiments. Bioinformatics analysis along with dual luciferase reporter assay and RIP assay were used to reveal the interaction between circLDLRAD3, miR-558 and Smad4. It was revealed that circLDLRAD3 exhibited low expression status in OSCC. CircLDLRAD3 inhibits proliferation, migration, and invasion of OSCC cells both in vitro and in vivo. Mechanistically, circLDLRAD3 could bind with miR-558 to positively regulate its target gene Smad4 expression. Rescue experiments further confirmed both miR-558 overexpression and Smad4 knockdown could reverse the influence of circLDLRAD3 on OSCC phenotypes. Moreover, circLDLRAD3 regulate the TGF-β signalling pathways to influence EMT through miR-558/Smad4 axis. Our study found that circLDLRAD3 is downregulated in OSCC and verified its tumour suppressor function and mechanism in OSCC through sponging miR-558 to regulate miR-558/Smad4/TGF-β axis. The characterization of such regulating network uncovers an important mechanism underlying OSCC progression, which could provide promising targets targeted therapy strategies for OSCC in the future.

MicroRNA-191 regulates oral squamous cell carcinoma cells growth by targeting PLCD1 via the Wnt/β-catenin signaling pathway

BackgroundStudies have shown that microRNA-191 (miR-191) is involved in the development and progression of a variety of tumors. However, the function and mechanism of miR-191 in oral squamous cell carcinoma (OSCC) have not been clarified.MethodsThe expression level of miR-191 in tumor tissues of patients with primary OSCC and OSCC cell lines were detected using real-time quantitative polymerase chain reaction (RT-qPCR) and western blot. OSCC cells were treated with miR-191 enhancers and inhibitors to investigate the effects of elevated or decreased miR-191 expression on OSCC cells proliferation, migration, cell cycle, and tumorigenesis. The target gene of miR-191 in OSCC cells were analyzed by dual-Luciferase assay, and the downstream signaling pathway of the target genes was detected using western blot assay.ResultsThe expression of miR-191 was significantly upregulated in OSCC tissues and cell lines. Upregulation of miR-191 promoted proliferation, migration, invasion, and cell cycle progression of OSCC cells, as well as tumor growth in nude mice. Meanwhile, reduced expression of miR-191 inhibited these processes. Phospholipase C delta1 (PLCD1) expression was significantly downregulated, and negatively correlated with the expression of miR-191 in OSCC tissues. Dual-Luciferase assays showed that miR-191-5p could bind to PLCD1 mRNA and regulate PLCD1 protein expression. Western blot assay showed that the miR-191 regulated the expression of β-catenin and its downstream gene through targeting PLCD1.ConclusionMicroRNA-191 regulates oral squamous cell carcinoma cells growth by targeting PLCD1 via the Wnt/β-catenin signaling pathway. Thus, miR-191 may serve as a potential target for the treatment of OSCC.

Yin Yang 1-Induced Long Noncoding RNA DUXAP9 Drives the Progression of Oral Squamous Cell Carcinoma by Blocking CDK1-Mediated EZH2 Degradation.

LncRNAs play a critical role in oral squamous cell carcinoma (OSCC) progression. However, the function and detailed molecular mechanism of most lncRNAs in OSCC are not fully understood. Here, a novel nuclear-localized lncRNA, DUXAP9 (DUXAP9), that is highly expressed in OSCC is identified. A high level of DUXAP9 is positively associated with lymph node metastasis, poor pathological differentiation, advanced clinical stage, worse overall survival, and worse disease-specific survival in OSCC patients. Overexpression of DUXAP9 significantly promotes OSCC cell proliferation, migration, invasion, and xenograft tumor growth and metastasis, and upregulates N-cadherin, Vimentin, Ki67, PCNA, and EZH2 expression and downregulates E-cadherin in vitro and in vivo, whereas knockdown of DUXAP9 remarkably suppresses OSCC cell proliferation, migration, invasion, and xenograft tumor growth in vitro and in vivo in an EZH2-dependent manner. Yin Yang 1 (YY1) is found to activate the transcriptional expression of DUXAP9 in OSCC. Furthermore, DUXAP9 physically interacts with EZH2 and inhibits EZH2 degradation via the suppression of EZH2 phosphorylation, thereby blocking EZH2 translocation from the nucleus to the cytoplasm. Thus, DUXAP9 can serve as a promising target for OSCC therapy.

FERMT2 upregulation in CAFs enhances EMT of OSCC and M2 macrophage polarization.

FERMT2 upregulation was associated with malignant tumor behaviors, including epithelial-to-mesenchymal (EMT). This study aimed to characterize the expression profile of FERMT2 in oral squamous cell carcinoma (OSCC) and to explore its involvement in the tumor microenvironment sculptured by oral cancer-associated fibroblasts (OCAFs). Previous bulk-seq (TCGA-HNSC) and single-cell RNA-seq data sets were retrieved for bioinformatic analysis. Human OSCC lines SCC15 and CAL27, primary normal oral fibroblasts (NOFs), OCAFs, and THP-1 cells were used for intro studies. FERMT2 expression was significantly higher in CAFs compared with OSCC tumor cells and normal fibroblasts. Higher FERMT2 expression might independently predict unfavorable disease-specific survival (DSS) in patients with OSCC. Knockdown of FERMT2 suppressed the expression and secretion of IGFBP7, SPARC, TIMP3, COL4A1, and IGFBP4 in OCAFs. OCAFs with FERMT2 knockdown had significantly weakened capability to induce the invasion of OSCC cells and the expression of mesenchymal markers. FERMT2 knockdown impaired the inducing effect of OCAFs on the migration of M0 macrophages and the expression of M2 macrophage markers. FERMT2 could modulate the production and secretion of IGFBP7, SPARC, COL4A1, and IGFBP4 in OCAFs, thereby inducing the EMT of OSCC and M2 macrophage polarization.

M2 Macrophages-Derived Exosomal miRNA-23a-3p Promotes the Progression of Oral Squamous Cell Carcinoma by Targeting PTEN.

Exosomes from tumor cells and immune cells regulate the tumor microenvironment through the biomolecules or microRNAs (miRNAs) they carry. This research aims to investigate the role of miRNA in exosomes derived from tumor-associated macrophages (TAMs) in the progression of oral squamous cell carcinoma (OSCC). RT-qPCR and Western blotting assays were used to determine the expression of genes and proteins in OSCC cells. CCK-8, Scratch assay and invasion-related proteins were utilized to detect the malignant progression of tumor cells. High-throughput sequencing predicted differentially expressed miRNAs in exosomes secreted by M0 and M2 macrophages. Compared with exosomes from M0 macrophages, exosomes from M2 macrophages led to enhanced proliferation and invasion of OSCC cells and inhibited their apoptosis. High-throughput sequencing results show that miR-23a-3p is differentially expressed in exosomes from M0 and M2 macrophages. MiRNA target gene database predicts that phosphatase and tensin homolog (PTEN) are target genes of miR-23a-3p. Further studies revealed that transfection of miR-23a-3p mimics inhibited PTEN expression in vivo and in vitro and promoted the malignant progression of OSCC cells, which was reversed by miR-23a-3p inhibitors. MiR-23a-3p in exosomes derived from M2 macrophages promotes malignant progression of OSCC. PTEN is a potential intracellular target of miR-23a-3p. MiR-23a-3p, an M2 macrophage-associated exosome, is a promising target for the future treatment of OSCC.

Knockdown of HMGB1 inhibits the crosstalk between oral squamous cell carcinoma cells and tumor-associated macrophages.

Tumor-associated macrophages (TAMs), the major component of the tumor microenvironment (TME), play distinctly different roles in different tumors. High mobility group box 1 (HMGB1), a nonhistone protein in the nucleus, can perform functions during inflammation and cancers. However, the role of HMGB1 in the crosstalk between oral squamous cell carcinoma (OSCC) cells and TAMs remains unclear. Here, we established a coculture system of TAMs and OSCC cells to explore the bidirectional effect and potential mechanism of HMGB1 in OSCC cell-TAM interactions. Our results showed that HMGB1 was significantly upregulated in OSCC tissues and positively associated with tumor progression, immune cell infiltration and macrophage polarization. Then, knocking down HMGB1 in OSCC cells inhibited the recruitment and polarization of cocultured TAMs. Moreover, the knockdown of HMGB1 in macrophages not only suppressed polarization, but also inhibited cocultured OSCC cell proliferation, migration and invasion in vitro and in vivo. Mechanistically, macrophages secreted higher levels of HMGB1 than OSCC cells, and dampening endogenous HMGB1 reduced HMGB1 secretion. Both OSCC cell-generated and macrophage-endogenous HMGB1 may regulate TAM polarization by promoting receptor TLR4 expression and NF-κB/p65 activation and enhancing IL-10/TGF-β expression. HMGB1 in OSCC cells may regulate macrophage recruitment via IL-6/STAT3. In addition, TAM-derived HMGB1 may affect aggressive phenotypes of cocultured OSCC cells by regulating the immunosuppressive microenvironment through the IL-6/STAT3/PD-L1 and IL-6/NF-κB/MMP-9 pathways. In conclusion, HMGB1 may regulate the crosstalk between OSCC cells and TAMs, including modulating macrophage polarization and attraction, enhancing cytokine secretion, and remodeling and creating an immunosuppressive TME to further affect OSCC progression.

Mesenchymal stem cells-derived IL-6 promotes invasion and metastasis of oral squamous cell carcinoma via JAK-STAT3 signalling.

Oral squamous cell carcinoma (OSCC) is often diagnosed with cervical lymph node metastasis. Mesenchymal stem cells (MSCs) and interleukin-6 (IL-6) signalling are considered to play important roles in promoting tumour malignancy. The detailed biological interaction of MSCs and IL-6 and the subsequent effect on OSCC metastasis remain largely unclear. This study aimed to determine the effects and molecular mechanism of MSCs-derived IL-6 on tumour invasion and metastasis. The effects of MSC-derived IL-6 and tocilizumab on the proliferation, mobility, and epithelial-mesenchymal transition (EMT) of OSCC cells and potential pathways were detected in vitro. In addition, a murine xenograft model was generated to verify the biological mechanism in vivo. The results showed that the expression of MSCs and EMT-related signals was increased in poorly differentiated OSCC tissues. MSCs released a higher level of IL-6 and promoted the proliferation, invasion, and metastasis of OSCC cells and solid neoplasms, which were activated by the downstream molecules JAK and STAT3. The results indicated that MSCs-derived IL-6-promoted tumour invasion and metastasis via JAK-STAT3 signalling. Blockade of this pathway by tocilizumab may be a potential treatment to improve the prognosis and survival rate of patients with OSCC.

MRTF-A/SRF signaling suppresses invasion of oral squamous cell carcinoma.

Serum response factor (SRF) and myocardial-associated transcription factor-A (MRTF-A) had different regulatory effects on the tumorigenesis and development in different cancers. However, the role of MRTF-A/SRF in oral squamous cell carcinoma (OSCC) remains to be determined. CCK-8 assay, cell scratch experiment, and transwell invasion assay were conducted to investigate the effects of MRTF-A/SRF on biological behavior of OSCC cells. The expression pattern and prognostic value of MRTF-A/SRF in OSCC were analyzed based on cBioPortal website and TCGA database. Protein-protein interaction network was visualized to identify protein functions. Go and KEGG pathway analyses were performed to investigate related pathways. The effect of MRTF-A/SRF on epithelial-mesenchymal transformation (EMT) of OSCC cells was explored by western blot assay. Overexpression of MRTF-A/SRF inhibited the proliferation, migration, and invasion of OSCC cells in vitro. High expression of SRF was related to better prognosis of OSCC patients on hard palate, alveolar ridge, and oral tongue. Besides, overexpression of MRTF-A/SRF inhibited the EMT of OSCC cells. SRF was closely related to the prognosis of OSCC. High expression of SRF and its co-activator MRTF-A inhibited proliferation, migration, and invasion of OSCC cells in vitro, possibly via EMT suppression.

ZNF677 inhibits oral squamous cell carcinoma growth and tumor stemness by regulating FOXO3a.

Oral squamous cell carcinoma (OSCC) is a common cancer with an increasing incidence worldwide. Zinc-finger proteins 677 (ZNF677) is involved in the progression and methylation of various cancers, but its role and mechanism in OSCC remain indeterminate. The expression of ZNF677 was analyzed by online database and immunohistochemistry, while the methylation level of ZNF677 was determined by the methylation-specific PCR. The role and mechanism of ZNF677 in the tumor cell growth, migration, invasion and stemness were addressed by cell counting kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU) incorporation, Transwell, wound-healing, sphere‑formation, and western blot assays. In addition, its function was also investigated in a xenografted mice model. The results showed that ZNF677 was lowly expressed in OSCC with a hypermethylation level, which predicted poor overall survival in patients with HNSC. Upregulation of ZNF677 reduced the cell viability, Edu positive cells, numbers of invasion cells, the migration ability, numbers of spheres formation and the expression of proliferation, migration and stemness related proteins in CAL-27 and SCC25 cells. Mechanically, the relative levels of p-AKT/AKT were decreased and the levels of p-FOXO3a/FOXO3a were increased in both cells overexpressed with ZNF677, which were reversed by the SC79 treatment. Moreover, interference of FOXO3a recovered the suppressive effects of ZNF677 overexpression on cell proliferation, migration, invasion and stemness of OSCC cells. Furthermore, overexpression of ZNF677 reduced the tumor volume and weight, and the relative protein level of p-AKT/AKT with an increased level of p-FOXO3a/FOXO3a, and improved pathological symptoms in vivo. Collectively, ZNF677 suppressed OSCC cells growth, migration, invasion and stemness through inhibiting AKT/FOXO3a pathway.

BST2 regulated by the transcription factor STAT1 can promote metastasis, invasion and proliferation of oral squamous cell carcinoma via the AKT/ERK1/2 signaling pathway.

Oral squamous cell carcinoma (OSCC) is one of the main types of head and neck squamous cell carcinoma. Although progress has been made in treating OSCC, it remains a threat to human health, and novel therapeutic strategies are needed to extend the lifespan of patients with OSCC. The present study, evaluated whether bone marrow stromal antigen2 (BST2) and STAT1 were potential therapeutic targets in OSCC. Small interfering RNA (siRNA) or overexpression plasmids were used to regulate BST2 or STAT1 expression. Western blotting and reverse transcription‑quantitative PCR were performed to assess changes in the protein and mRNA expression levels of signaling pathway components. The effects of BST2 and STAT1 expression changes on the migration, invasion and proliferation of OSCC cells were assessed using the scratch test assay, Transwell assay and colony formation assay invitro, respectively. Cell‑derived xenograft models were used to evaluate the impact of BST2 and STAT1 on the occurrence and development of OSCC invivo. Finally, it was demonstrated that BST2 expression was significantly upregulated in OSCC. Furthermore, it was demonstrated that high expression of BST2 in OSCC contributed to the metastasis, invasion and proliferation of OSCC cells. Moreover, it was demonstrated that the promoter region of BST2 was regulated by the transcription factor STAT1, and that the STAT1/BST2 axis could affect the behavior of OSCC via the AKT/ERK1/2 signaling pathway. Invivo studies also demonstrated that STAT1 downregulation inhibited OSCC growth by down‑regulating BST2 expression via the AKT/ERK1/2 signaling pathway.

Suprabasin enhances the invasion, migration, and angiogenic ability of oral squamous cell carcinoma cells under hypoxic conditions.

Suprabasin (SBSN) is a secreted protein that is isolated as a novel gene expressed in differentiated keratinocytes in mice and humans. It induces various cellular processes such as proliferation, invasion, metastasis, migration, angiogenesis, apoptosis, therapy and immune resistance. The role of SBSN was investigated in oral squamous cell carcinoma (OSCC) under hypoxic conditions using the SAS, HSC‑3, and HSC‑4 cell lines. Hypoxia induced SBSN mRNA and protein expression in OSCC cells and normal human epidermal keratinocytes (NHEKs), and this was most prominent in SAS cells. The function of SBSN in SAS cells was analyzed using 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide (MTT); 5‑bromo‑2'‑deoxyuridine (BrdU); cell cycle, caspase 3/7, invasion, migration, and tube formation assays; and gelatin zymography. Overexpression of SBSN decreased MTT activity, but the results of BrdU and cell cycle assays indicated upregulation of cell proliferation. Western blot analysis for cyclin‑related proteins indicated involvement of cyclin pathways. However, SBSN did not strongly suppress apoptosis and autophagy, as revealed by caspase 3/7 assay and western blotting for p62 and LC3. Additionally, SBSN increased cell invasion more under hypoxia than under normoxia, and this resulted from increased cell migration, not from matrix metalloprotease activity or epithelial‑mesenchymal transition. Furthermore, SBSN induced angiogenesis more strongly under hypoxia than under normoxia. Analysis using reverse transcription‑quantitative PCR showed that vascular endothelial growth factor (VEGF) mRNA was not altered by the knockdown or overexpression of SBSN VEGF, suggesting that VEGF is not located downstream of SBSN. These results demonstrated the importance of SBSN in the maintenance of survival and proliferation, invasion and angiogenesis of OSCC cells under hypoxia.

MiR-199a-5p-Regulated SMARCA4 Promotes Oral Squamous Cell Carcinoma Tumorigenesis.

SWI/SNF related, matrix associated, actin-dependent regulator of chromatin, subfamily a, member 4 (SMARCA4, also known as BRG1), an ATPase subunit of the switch/sucrose non-fermentable (SWI/SNF) chromatin remodeling complex, plays an important regulatory role in many cytogenetic and cytological processes during cancer development. However, the biological function and mechanism of SMARCA4 in oral squamous cell carcinoma (OSCC) remain unclear. The present study aimed to investigate the role of SMARCA4 in OSCC and its potential mechanism. Using a tissue microarray, SMARCA4 expression was found to be highly upregulated in OSCC tissues. In addition, SMARCA4 upregulate expression led to increased migration and invasion of OSCC cells in vitro, as well as tumor growth and invasion in vivo. These events were associated with the promotion of epithelial-mesenchymal transition (EMT). Bioinformatic analysis and luciferase reporter assay confirmed that SMARCA4 is a target gene of microRNA miR-199a-5p. Further mechanistic studies showed that the miR-199a-5p regulated SMARCA4 can promote the invasion and metastasis of tumor cells through EMT. These findings indicate that the miR-199a-5p- SMARCA4 axis plays a role in tumorigenesis by promoting OSCC cell invasion and metastasis through EMT regulation. Our findings provide insights into the role of SMARCA4 in OSCC and the mechanism involved, which may have important implications for therapeutic purposes.

Serum Response Factor-Regulated IDO1/Kyn-Ahr Pathway Promotes Tumorigenesis of Oral Squamous Cell Carcinoma

Serum response factor (SRF) regulates pro-carcinogenic genes in various cancers, but its role in oral squamous cell carcinoma (OSCC) remains unclear. SRF expression in 70 OSCC samples was detected via immunohistochemistry. Abundant SRF expressed in OSCC tissues was closely associated with tumor metastasis. SRF-overexpressing OSCC cells were constructed to evaluate how SRF affects OSCC cell tumorigenesis and epithelial-to-mesenchymal transition (EMT) in vitro and in vivo. Overexpressed SRF increased OSCC cell migration and invasion in vitro and tumor growth and invasion in vivo. This promoted EMT, characterized by decreased and increased expression of E- and N-cadherin, respectively. Furthermore, an analysis of RNA sequences of transcriptional targets of SRF showed that SRF transactivated the indoleamine 2, 3-dioxygenase 1 (IDO1)/kynurenine-aryl hydrocarbon receptor (Kyn-AhR) signaling pathway in OSCC cell lines. Direct SRF binding to the IDO1 gene promoter upregulated transcription, which was detected through chromatin immunoprecipitation and dual luciferase reporter assays. Inhibiting IDO1 or AhR impaired SRF-induced migration and invasion and prevented EMT in OSCC cells. Our results demonstrated that SRF is a critical regulator of the IDO1/Kyn-AhR signaling pathway. This in turn increases OSCC cell migration and invasion by modulating EMT, which, consequently, favors OSCC cell growth and metastasis. We revealed a novel molecular mechanism through which SRF modulates OSCC metastasis. This should provide potential targets or biomarkers for OSCC diagnosis and treatment.

Clinical significance of L1CAM expression and its biological role in the progression of oral squamous cell carcinoma.

L1 cell adhesion molecule (L1CAM) has been implicated in the progression and metastasis of numerous cancers. However, the role of L1CAM in oral squamous cell carcinoma (OSCC) is not well characterized. In the present study, the expression of L1CAM was examined in oral tongue squamous cell carcinoma (OTSCC) tissue samples by immunohistochemistry, the clinicopathological significance of L1CAM expression was evaluated by chi‑squared test, and the overall survival (OS) rate was analyzed using Kaplan‑Meier method according to the expression of L1CAM. In addition, it was aimed to elucidate the biological role of L1CAM and the underlying molecular mechanisms by which L1CAM functions in OSCC cells in relation to epithelial‑mesenchymal transition (EMT) and PI3K/AKT/ERK signaling pathways. Thus, the functions of L1CAM on the OSCC cell proliferation, migration and invasion, and the activation of EMT and PI3K/AKT/ERK signaling pathways were investigated invitro. Positive L1CAM expression was found in 32.5% of OTSCC cases and was significantly correlated with high histologic grade, greater depth of invasion, lymph node metastasis, perineural invasion, advanced stage, and survival status. Patients with positive L1CAM expression had significantly lower OS rate. Particularly in patients with early OTSCC, L1CAM expression was strongly associated with worse prognosis. Overexpression of the recombinant human L1CAM protein significantly increased cell proliferation, migration and invasion. By contrast, L1CAM knockdown using small interfering RNA significantly inhibited cell proliferation, migration, invasion and EMT. Moreover, phosphorylated (p)‑PI3K, p‑AKT and p‑ERK expression levels were significantly reduced by L1CAM knockdown. Taken together, the findings of the present study suggested that L1CAM could be a potential prognostic marker and a promising therapeutic target in OSCC.

RELA promotes the progression of oral squamous cell carcinoma via TFAP2A-Wnt/β-catenin signaling.

Oral squamous cell carcinoma (OSCC) has emerged as the most prevailing oral malignancy worldwide, characterized by cervical solid lymph node metastasis and strong local invasiveness. Overexpression of Transcription Factor AP-2 alpha (TFAP2A) is observed in a significant proportion of OSCC cases. In this study, we aimed to elucidate the function of TFAP2A in the progression of OSCC and the related molecular signaling pathways. The role of RELA was predicted using bioinformatics analysis. The mRNA abundances of RELA, TFAP2A, and β-catenin were assessed by Western blot and quantitative real-timePCR. The relationship between RELA, TFAP2A, and β-catenin and their correlation with clinicopathological characteristics of OSCC was evaluated. The target of RELA and TFAP2A was identified by the chromatin immunoprecipitation as well as luciferase reporter assay. The colony formation assay and MTS assay were performed to determine the proliferative level of OSCC cells. OSCC cell motility was determined by Transwell assay and wound-healing assay. The protein expressions of epithelial-mesenchymal transition-associated factors were evaluated by Western blot. The expressions of RELA and TFAP2A were elevated in OSCC, and their expressions displayed a positive correlation. The expression levels of RELA and TFAP2A were found to be associated with TNM staging and lymphatic metastasis of OSCC patients. RELA upregulation promoted OSCC progression, as manifested by increased levels of proliferation, invasion, and migration of OSCC cells. We also demonstrated that RELA was directly bound to the promoter of TFAP2A transcription, which activated multiple malignant and metastatic phenotypes. Furthermore, TFAP2A activated the Wnt/β-catenin signaling by targeting the promoter regions of β-catenin. The study found that RELA is critical for promoting the progression of OSCC via the RELA-TFAP2A-Wnt/β-catenin signaling pathway. The RELA-TFAP2A-Wnt/β-catenin signaling pathway is a potential target for reducing the aggressiveness of OSCC.