Oral Squamous Cell Carcinoma Cells Research Articles

Silencing ANLN hinders the proliferation, migration, invasion, and angiogenesis of oral squamous cell carcinoma

BackgroundThe actin-binding protein anillin (ANLN) functions as an oncogene in various cancers but has not been fully studied in oral squamous cell carcinoma (OSCC). This study aimed to investigate the expression of ANLN in OSCC tissues and cell lines, to better understand its role in mediating proliferative, angiogenic, invasive, and metastatic capabilities in this type of cancer. MethodsANLN mRNA and protein levels were assessed using qPCR and western immunoblotting. The expression intensity of ANLN was evaluated using immunohistochemical (IHC) staining. Biological functional assays were employed to characterize the behavior of OSCC cells influenced by ANLN. Additionally, comprehensive bioinformatics analysis, including GO analysis and KEGG enrichment analysis, was performed on differentially expressed genes in ANLN-mediated pathways. ResultsOSCC tumors and cell lines exhibited higher ANLN expression. Silencing of ANLN significantly suppressed OSCC cell proliferation, as evidenced by a significant reduction in the Ki-67 index both in vitro and in vivo. The migration and invasive ability of OSCC cells were markedly diminished, coinciding with a decrease in epithelial-mesenchymal transition activity. ANLN was also found to promote angiogenic activity in OSCC cells, partly through synergistic effects mediated by vascular endothelial growth factor A (VEGFA). Downregulation of ANLN expression led to decreased VEGFA levels, resulting in reduced angiogenesis characterized by fewer vascular branches. ConclusionsOur findings highlight the promising role of ANLN as a biomarker for both diagnostic and prognostic in OSCC. Targeting ANLN with inhibitory strategies could impede the oncogenesis processes at the core of OSCC development, presenting significant opportunities for advancing therapeutic interventions.

Multispectral fluorescence imaging of EGFR and PD-L1 for precision detection of oral squamous cell carcinoma: a preclinical and clinical study

BackgroundEarly detection and treatment are effective methods for the management of oral squamous cell carcinoma (OSCC), which can be facilitated by the detection of tumor-specific OSCC biomarkers. The epidermal growth factor receptor (EGFR) and programmed death-ligand 1 (PD-L1) are important therapeutic targets for OSCC. Multispectral fluorescence molecular imaging (FMI) can facilitate the detection of tumor multitarget expression with high sensitivity and safety. Hence, we developed Nimotuzumab-ICG and Atezolizumab-Cy5.5 imaging probes, in combination with multispectral FMI, to sensitively and noninvasively identify EGFR and PD-L1 expression for the detection and comprehensive treatment of OSCC.MethodsThe expression of EGFR and PD-L1 was analyzed using bioinformatics data sources and specimens. Nimotuzumab-ICG and Atezolizumab-Cy5.5 imaging probes were developed and tested on preclinical OSCC cell line and orthotopic OSCC mouse model, fresh OSCC patients’ biopsied samples, and further clinical mouthwash trials were conducted in OSCC patients.ResultsEGFR and PD-L1 were specifically expressed in human OSCC cell lines and tumor xenografts. Nimotuzumab-ICG and Atezolizumab-Cy5.5 imaging probes can specifically target to the tumor sites in an in situ human OSCC mouse model with good safety. The detection sensitivity and specificity of Nimotuzumab-ICG in patients were 96.4% and 100%, and 95.2% and 88.9% for Atezolizumab-Cy5.5.ConclusionsEGFR and PD-L1 are highly expressed in OSCC, the combination of which is important for a precise prognosis of OSCC. EGFR and PD-L1 expression can be sensitively detected using the newly synthesized multispectral fluorescence imaging probes Nimotuzumab-ICG and Atezolizumab-Cy5.5, which can facilitate the sensitive and specific detection of OSCC and improve treatment outcomes.Trial registrationChinese Clinical Trial Registry, ChiCTR2100045738. Registered 23 April 2021, https://www.chictr.org.cn/bin/project/edit?pid=125220

The Investigation of Nfκb Inhibitors to Block Cell Proliferation in OSCC Cells Lines.

Oral cancers, with oral squamous cell carcinoma (OSCC) as the predominant type, have a significant impact on morbidity and mortality rates. Therefore, targeting the NFκB pathway shows promise in cancer therapy. This study investigated the impact of two NFκB inhibitors, LY2409881 and MLN4924, on cell proliferation, apoptosis susceptibility, and in vivo tumorigenesis in OSCC cell lines CAL27 and SCC15. The results revealed that both LY2409881 and MLN4924 effectively suppressed cell proliferation, induced apoptosis, and arrested the cell cycle at the G2/M phase-a phenomenon likely associated with the NFκB pathway. Furthermore, MLN4924 demonstrated potent inhibitory effects on cell proliferation at low μM concentrations, surpassing the effectiveness of LY2409881 as an inhibitor. (All results: p<0.05) Conclusion: These findings highlight the potential of LY2409881 and MLN4924 as novel therapeutic agents for OSCC, thereby offering new insights for the clinical management of this condition.

LncRNAPVT1 is Associated with Cancer-Associated Fibroblasts Proliferation Through Regulating TGF-βin Oral Squamous Cell Carcinoma

ABSTRACT Introduction Human oral squamous cell carcinoma (OSCC) is the most common type of oral cancer and has a poor survival rate. Cell-cell communication between OSCC cells and cancer-associated fibroblasts (CAFs) plays important roles in OSCC progression. We previously demonstrated that CAFs promote OSCC cell migration and invasion. However, how OSCC cells influence CAFs proliferation is unknown. Methods Knockdown of PVT1 was confirmed using lentivirus infection technique. CAFs in tissues were identified by staining the cells with α-SMA using immunohistochemical technique. CCK-8 assay was used to evaluate cell proliferation. The mRNA level of a gene was measured by qRT-PCR. Secreted TGF-β were detected using ELISA assay. Results We found that knockdown of the long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) was associated with a low density of CAFs in xenograft tumors in mice; further analysis revealed that PVT1 in OSCC cells induced CAF proliferation through transforming growth factor (TGF)-β. Discussion Our results demonstrate that lncRNA PVT1 in tumor cells participates in CAF development in OSCC by regulating TGF-β. This study revealed a new mechanism by which PVT1 regulates OSCC progression and PVT1 is a potential therapeutic target in OSCC

Extracellular vesicle-bound VEGF in oral squamous cell carcinoma and its role in resistance to Bevacizumab Therapy

BackgroundVascular endothelial growth factor (VEGF) is an important proangiogenic factor and has been considered as a key target of antiangiogenetic therapy in oral squamous cell carcinoma (OSCC). However, clinical application of bevacizumab, a specific VEGF antibody, didn’t improve the survival rate of OSCC patients. One possible explanation is that VEGF gene expresses diverse isoforms, which associate with extracellular vesicles (EVs), and EVs potentially contribute to VEGF resistance to bevacizumab. However, clear solution is lacking in addressing this issue.MethodsExpression of VEGF isoforms in OSCC cells was confirmed by reverse transcription and polymerase chain reaction (RT-PCR) and western blot. EVs isolated from OSCC cell’s conditioned medium (CM) were characterized by western blot, transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA). Flow cytometry, immunogold labeling and western blot were applied to study the VEGF on EVs. Tube formation assay and Matrigel plug angiogenesis assay were used for analyzing the angiogenesis capacity of EV-VEGF.ResultsThe most popular isoforms expressed by VEGF gene are VEGF121, VEGF165 and VEGF189. In this study, we demonstrated that all three isoforms of mRNA could be detected at varying levels in OSCC cells, while only VEGF165 and VEGF189 proteins were found. CM derived from OSCC cells, both soluble and non-soluble forms of VEGF could be detected. We further confirmed the presence of VGEF189 bound to EVs as a non-soluble form. EV-bound VEGF189 presented angiogenic activity, which could not be neutralized by bevacizumab. It was found that VEGF189 bound to EVs by heparan sulfate proteoglycans (HSPG). In addition, the angiogenic effect of EV-VEGF could be reversed by surfen, a kind of HSPG antagonist both in vitro and in vivo.ConclusionAntagonists targeting HSPG might potentially overcome the resistance of EV-VEGF to bevacizumab and serve as an alternative for anti-VEGF therapy in OSCC.

EZH2 Inhibition to Counteract Oral Cancer Progression through Wnt/β-Catenin Pathway Modulation.

Oral squamous cell carcinoma (OSCC) is one of the most common human malignancies worldwide. The molecular mechanisms of OSCC pathogenesis are still unknown; however, in recent years, several reports have focused on the role of enhancer of zeste homolog 2 (EZH2) in OSCC. Therefore, in this study we aimed to investigate the effects of GSK343, a selective EZH2 inhibitor, and its impact on the signaling pathways in OSCC, using an in vitro and in vivo orthotopic model. In the in vitro model, GSK343 (1, 10, and 25 μM) significantly decreased OSCC cell viability and cell migration through EZH2 inhibition, modulating NF-κB/IκBα pathway activation and eNOS, VEGF, and TGFβ expression, important markers of angiogenesis. In the in vivo model, GSK343 (5 mg/kg and 10 mg/kg) restored tongue tissue architecture and reduced tumor progression through EZH2 inhibition and Wnt/β-catenin signaling pathway modulation. Moreover, GSK343 reduced the expression of inflammatory mediators; eNOS and TGFβ, markers of angiogenesis; and CD31 and CD34, markers of micro vessel density, respectively. In conclusion, our data demonstrate that GSK343 counteracts oral cancer progression through EZH2/Wnt/β-catenin pathway modulation, suggesting that it could be a promising therapeutic approach for OSCC management.

The role of SEMG1 overexpression in OSCC tumorigenesis and its relation with metabolic molecules.

This study aimed to investigate the expression and biological significance of Semenogelin 1 (SEMG1), a member of the cancer-testis antigen family, in oral squamous cell carcinoma (OSCC). Further, we explored its potential association with metabolism-related molecules. SEMG1 expression levels in OSCC were determined through immunohistochemistry, flow cytometry, and Western blot analyses. To decipher the biological implications of SEMG1 in OSCC, the CAL27 OSCC cell line was either stably overexpressed with SEMG1 or subjected to SEMG1-shRNA knockdown. The relationship between clinicopathological parameters and SEMG1 expression in OSCC patients was also assessed. SEMG1 was found to be overexpressed in OSCC, though its expression was not influenced by the pathological grade. The fluorescent dihydroethidium assay indicated that SEMG1 augmented reactive oxygen species production. The mitochondrial membrane potential assay suggested a significant upregulation of mitochondrial membrane potential by SEMG1. Cell cycle assessments highlighted that SEMG1 overexpression led to a notable rise in cells entering the S-phase. Additionally, a strong correlation between SEMG1 expression and both ENO1 and PKM2 expression in OSCC was observed. The findings underscore the elevated expression of SEMG1 in OSCC and its contributory role in the tumorigenesis of OSCC patients.

MiR-185–5p rewires cisplatin resistance by restoring miR-203a-3p expression via downregulation of SOX9

Chemotherapeutic drug resistance is a challenge for the effective treatment of OSCC. There are a couple of studies on the involvement of microRNAs (miRNAs) in chemoresistance of oral squamous cell carcinoma (OSCC), but the exact molecular events in many cases are not clearly understood. In this work, we intend to track down key miRNA(s) and unveil their regulatory molecular mechanisms in imparting chemoresistance in this lethal cancer. We analyzed gene and miRNA array profiles of drug-resistant OSCC cells, predicted miRNA targets, performed enrichment analysis, and validated our findings in cisplatin-sensitive and cisplatin-resistant SCC9 and H357 OSCC cells. We evaluated the anticancer and chemosensitivity roles of selected miRNA by adopting several molecular assays like qRT-PCR, MTT assay, wound healing assay, fluorescence imaging by DCFHDA, AO/EB staining, DAPI, and γ-H2AX accumulation assay. We also validated the miRNA-target binding by qRT-PCR and luciferase reporter assay. Among the enriched miRNAs, we found miR-185–5p downregulated in cisplatin-resistant OSCC cells as a signature miRNA modulating chemoresistance. The upregulation of miR-185–5p by mimic transfection restores cisplatin sensitivity by decreasing cell viability in a dose-dependent manner and increasing ROS-induced DNA damage and apoptosis. miR-185–5p overexpression increases miR-203a-3p expression through negative regulation of SOX9. siRNA-mediated silencing of the SOX9 also shows similar results. Mechanistically, miR-185–5p dependent miR-203a-3p expression decreases cisplatin efflux and cisplatin-induced DNA damage repair by regulating ABCC1, ABCB1, RRM2, and RAN. This study will pave the way for employing this miR-185–5p as a combination therapeutic strategy to combat cisplatin resistance in oral cancer.

PRELP inhibits the progression of oral squamous cell carcinoma via inactivation of the NF-κB pathway

ObjectivesThe aim of this study was to investigate the role and molecular mechanism of proline/arginine-rich end leucine-rich repeat protein (PRELP), a secreted protein in extracellular matrix, in oral squamous cell carcinoma (OSCC) progression. DesignPRELP expression in OSCC was analyzed in the Gene Set Enrichment (GSE) 138206, GSE37991, and GSE23558 datasets as well as cell lines. Also, PRELP expression and its relationship with prognosis and immune infiltration in head and neck squamous cell carcinoma (HNSCC) were confirmed by bioinformatics analysis. The proliferation, apoptosis, invasion, epithelial-to-mesenchymal transition (EMT) and NF-κB activation were detected after alteration of PRELP expression in OSCC cells using CCK-8, EdU, flow cytometry, Transwell, real-time PCR, immunofluorescence and Western blot. Additionally, an NF-κB inhibitor PDTC was used to confirm the regulation mechanism of PRELP. ResultsThe expression of PRELP in OSCC tissues, cells and in HNSCC samples was low. HNSCC patients with higher PRELP expression was associated with longer overall survival. A positive correlation between PRELP expression and immune cell infiltration was found in HNSCC. Upregulation of PRELP inhibited, whereas PRELP silencing promoted, the proliferation, invasion and EMT of OSCC cells. Also, overexpression of PRELP promoted cell apoptosis. Mechanistically, PRELP suppressed p65 phosphorylation and nuclear translocation. And PDTC treatment partially reversed the influences of PRELP knockdown on the malignant behaviors in OSCC cells. ConclusionPRELP suppressed OSCC progression via inactivation of the NF-κB pathway. Targeting PRELP may be a potential approach for OSCC treatment.

Pituitary tumor‑transforming gene 1 regulates the senescence and apoptosis of oral squamous cell carcinoma in a p21‑dependent DNA damage response manner.

Pituitary tumor‑transforming gene 1 (PTTG1), also known as securin, is a proto‑oncogene involved in the development of various cancers by promoting cell proliferation and mobility. However, its underlying biological mechanisms in oral squamous cell carcinoma (OSCC) progression remain unclear. in the present study, it was sought to elucidate the role of PTTG1 as an oncogene in OSCC progression and was attempted to unravel the underlying mechanism and impact of PTTG1 expression on cell cycle, cell death, and cellular senescence. The effect of double strand break on PTTG1 expression was investigated in OSCC growth. To identify the role of PTTG1 in OSCC growth, the cell viability and senescence was analyzed by EdU and senescence‑associated beta‑galactosidase (SA‑β‑gal) assay, respectively. To verify the DNA damage‑induced senescence of PTTG1, the chromosomal damage in OSCC was analyzed in vitro. Finally, the effect of PTTG1 on tumor growth and gene expression related to cell viability and DNA damaged‑induced senescence was investigated in vivo. PTTG1 expression was compared between OSCC and healthy patient samples (n=32) using reverse transcription‑quantitative PCR and immunohistochemistry; and it was found that PTTG1 expression was upregulated in OSCC. Small interfering RNA‑mediated knockdown of PTTG1 in two OSCC cell lines revealed that PTTG1 downregulation significantly inhibited cell proliferation and arrested the cell cycle pathway as evidenced by changes in checkpoint genes (such as cyclin D1, E and B1). PTTG1 knockdown also increased apoptosis, as evidenced by the upregulation of apoptotic genes [such as cleaved (c‑) Caspase‑7 and c‑poly (ADP‑ribose) polymerase]. Moreover, PTTG1 downregulation promoted cellular senescence, as shown by western blotting and SA‑β‑gal staining. Finally, senescence‑induced DNA damage was observed in OSCC cells, which accelerates genomic instability, through chromosomal damage analysis. Taken together, the present findings suggested that PTTG1 acts as a proto‑oncogene; regulates cell proliferation, cell cycle, cellular senescence and DNA damage in OSCC; and may serve as a novel diagnostic biomarker and potential therapeutic target for OSCC.

DAZAP1 Phase Separation Regulates Mitochondrial Metabolism to Facilitate Invasion and Metastasis of Oral Squamous Cell Carcinoma.

Tumor invasion and metastasis are the underlying causes of the high mortality rate of oral squamous cell carcinoma (OSCC). Energy metabolism reprogramming has been identified as a crucial process mediating tumor metastasis, thus indicating an urgent need for in-depth investigation of the specific mechanisms of tumor energy metabolism. Here, we identified an RNA-binding protein, DAZ associated protein 1 (DAZAP1), as a tumor-promoting factor with an important role in OSCC progression. DAZAP1 was significantly upregulated in OSCC, which enhanced the migration and invasion of OSCC cells and induced the epithelial-mesenchymal transition (EMT). RNA-seq analysis and experimental validation demonstrated that DAZAP1 regulates mitochondrial energy metabolism in OSCC. Mechanistically, DAZAP1 underwent liquid-liquid phase separation (LLPS) to accumulate in the nucleus where it enhanced cytochrome-c oxidase 16 (COX16) expression by regulating pre-mRNA alternative splicing, thereby promoting OSCC invasion and mitochondrial respiration. In mouse OSCC models, loss of DAZAP1 suppressed EMT, downregulated COX16, and reduced tumor growth and metastasis. In OSCC patient samples, expression of DAZAP1 positively correlated with COX16, and high expression of both proteins was associated with poor patient prognosis. Together, these findings revealed a mechanism by which DAZAP1 supports mitochondrial metabolism and tumor development of OSCC, suggesting the potential of therapeutic strategies targeting DAZAP1 to block OSCC invasion and metastasis.

Circ-CDK8 regulates SLC7A11-mediated ferroptosis by inhibiting miR-615-5p to promote progression in oral squamous cell carcinomas.

Introduction: Ferroptosis is a new mode of programmed cell death distinct from necrosis, apoptosis, and autophagy, induced by iron-ion-dependent lipid peroxide accumulation. Circular RNAs are a class of endogenous non-coding RNAs that regulate the biological behavior of tumors. However, the role of circ-CDK8 in regulating ferroptosis, migration, and invasion of oral squamous cell carcinoma (OSCC) remains unknown. Methods: The effect of circ-CDK8 on OSCC cell ferroptosis, migration, and invasion was evaluated using CCK-8, wound healing, transwell, reactive oxygen species (ROS), malondialdehyde (MDA), and GSH assays and Western blotting. Bioinformatics analyses and luciferase reporter assays were performed and revealed targeted relationships between circ-CDK8 and miR-615-5p, miR-615-5p and SLC7A11. Interference with circ-CDK8 expression reduced SLC7A11 expression by sponging miR-615-5p, suppressed OSCC cell migration and invasion, and promoted ferroptosis by increasing ROS, MDA, and iron levels and decreasing GSH and GPX4 levels in OSCC cells. Furthermore, in vivo, animal experiments confirmed that circ-CDK8 interference inhibited OSCC cell proliferation and SLC7A11 expression. Results: Collectively, this study revealed a novel strategy to upregulate erastin-induced ferroptosis in OSCC cells via the circ-CDK8/miR-615-5p/SLC7A11 axis, providing new insights into OSCC and a potential therapeutic strategy for OSCC.

The efficacy and potential mechanisms of pyrotinib in targeting EGFR and HER2 in advanced oral squamous cell carcinoma

BackgroundHuman epidermal growth factor receptor 2 (HER2) plays an important role in the progression of multiple solid tumors and induces resistance to epidermal growth factor receptor (EGFR) target treatment. However, the expression status and the clinical significance of HER2 in oral squamous cell carcinoma (OSCC) is still controversial. Pyrotinib (PYR) is a promising novel EGFR/HER2 dual inhibitor, whose efficacy in OSCC has not been determined.Methods57 locally advanced de novo OSCC patients were included in this study to investigate the relationship between the HER2 expression levels and the prognosis by the tissue microarray analysis (TMA). In vitro and in vivo experiments were performed to retrieve the efficacy of PYR in OSCC. The main downstream of HER2 was evaluated by western blotting in OSCC cell lines and xenograft tumors to explore the potential mechanism of PYR.ResultsThis study revealed the primary tumor of OSCC had higher HER2 expression levels. Patients with HER2 overexpression had poor overall survival (P < 0.014) and poor disease free survival (P < 0.042). In vitro, PYR suppressed the proliferation, colony formation and migration of OSCC cells. It also promoted apoptosis of OSCC cells and induced cell cycle arrest. Furthermore, PYR was able to inhibit the occurrence and development of OSCC effectively in vivo. Western blotting revealed that PYR suppressed OSCC by inhibiting the phosphorylation of HER2, AKT and ERK.ConclusionsThis study exhibited the anti-OSCC effects of PYR in vitro and in vivo, and demonstrated PYR inhibited OSCC cells by inducing apoptosis via the HER2/ AKT and ERK pathway. The result of this study also indicated locally advanced OSCC patients might benefit from HER2 assay and EGFR/HER2 dual inhibit treatment.

CKIP-1 silencing suppresses OSCC via mitochondrial homeostasis-associated TFAM/cGAS-STING signalling axis.

Limited effective targets have challenged the treatment of oral squamous cell carcinoma (OSCC). Casein kinase 2 interacting protein 1 (CKIP-1) is a scaffold protein involved in various diseases. However, the role of CKIP-1 in OSCC remains unclear. The aim of this study was to explore the regulatory role of CKIP-1 in OSCC, as well as the involved mechanism. First, higher expression of CKIP-1 in OSCC tissues and cell lines were found. Series of gain- and loss-of-function experiments demonstrated suppressed malignant behaviours and enhanced apoptosis of OSCC cells when CKIP-1 was silenced. Also, inhibited tumour growth in CKIP-1-silenced group were proved. Further, mitochondrial transcription factor A (TFAM) downregulation, increased ROS production, decreased mitochondrial membrane potential and cGAS-STING activation in CKIP-1-silenced group were observed. The involvement of mitochondrial homeostasis-related TFAM/cGAS-STING axis in CKIP-1-silenced OSCC cells was finally demonstrated by tetramethylpyrazine (TMP) that inhibits TFAM degradation. Taken together, our study demonstrated that CKIP-1 silencing could significantly antagonize OSCC via TFAM/cGAS-STING axis, which may provide a candidate target for OSCC treatment.

PER2 binding to PDK1 enhances the cisplatin sensitivity of oral squamous cell carcinoma through inhibition of the AKT/mTOR pathway

Cisplatin (CDDP) is a cornerstone chemotherapeutic agent used to treat oral squamous cell carcinoma (OSCC) and many solid cancers. However, the mechanisms underlying tumor resistance to CDDP obscure the enhancement of its therapeutic efficacy. In this study, we unveil diminished expression of the biological clock gene PER2 in OSCC, negatively correlated with the expression of multidrug resistance protein 1 (MDR1) and multidrug resistance-associated protein 1 (MRP1). The overexpression of PER2 suppressed MDR1 and MRP1 expression and increased intracellular CDDP levels and DNA damage, thereby bolstering OSCC cell sensitivity to CDDP. In vivo tumorigenic assays corroborated that PER2 overexpression notably increased OSCC sensitivity to CDDP, augmenting the suppression of OSCC tumorigenesis. Co-immunoprecipitation, GST pull-down, and cycloheximide tracking assays revealed that PER2, via its C-terminal domain, bound to and diminishes PDK1 stability. The degradation of PDK1 was further dependent on the suppression of the AKT/mTOR pathway to enhance the sensitivity of OSCC cells to CDDP. Our study supports PER2 as a target for improving CDDP sensitivity in OSCC, and the combination of PER2 and CDDP is a novel strategy with potential clinical therapeutic value.

BCAT1 promotes cell proliferation, migration, and invasion via the PI3K-Akt signaling pathway in oral squamous cell carcinoma.

To analyze the expression, biological function of branched chain amino-acid transaminase 1 (BCAT1) in oral squamous cell carcinoma (OSCC). Real-time PCR and immunohistochemistry were used to analyze the expression of BCAT1 protein in OSCC and normal oral tissues. Based on the clinicopathological information of patients, the relationship between the expression of BCAT1 protein and other clinicopathological factors was analyzed. Real-time PCR and western blot assays were used to analyze the expression of BCAT1 gene and protein in normal human oral keratinocytes (HOK) and human OSCC cells, respectively. After BCAT1 overexpression or knockdown, the proliferation, cell cycle, migration, and invasion of human OSCC cells were analyzed by CCK8, flow cytometry, wound healing, and transwell invasion assays, respectively. After adding the BCAT1 inhibitor EGR240 to OSCC cells, the changes in cell proliferation, migration, and invasion ability in OSCC cells were analyzed. Based on the TCGA database, the involved signal pathway in BCAT1-related and BCAT1-binding genes was obtained for Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, verified by western blot assays. After inhibiting PI3K, the effect of BCAT1 on the expression of the downstream phosphorylated protein of the PI3K-Akt signaling pathway was analyzed by western blot assays. The relationship between the expression of BCAT1 and EMT-related protein of OSCC cells was also analyzed. The expression of BCAT1 gene and protein were upregulated in OSCC tissue, which positively correlated with the pathological grade of patients with OSCC. Compared with normal oral keratinocytes, BCAT1 gene and protein were upregulated in OSCC cells. BCAT1 overexpression promoted the proliferation, migration, and invasion of OSCC cells. BCAT1 knockdown or inhibition could reduce the proliferation, migration, and invasion abilities of OSCC cells. The results of bioinformatics analysis and Western bolt showed that BCAT1 could regulate the activation of PI3K-Akt signaling pathway, and promote epithelial-mesenchymal transition (EMT) of OSCC cells. BCAT1 could promote the proliferation, migration, and invasion of OSCC cells via PI3K-Akt signaling pathway, which is a potential therapeutic target for OSCC.

Knockdown of Stanniocalcin-1 inhibits growth and glycolysis in oral squamous cell carcinoma cells.

Oral squamous cell carcinoma (OSCC) is the most common malignancy among head and neck squamous cell carcinomas. Targeted therapy plays a crucial role in the treatment of OSCC. However, new and more targets are still needed to develop. Stanniocalcin-1 (STC-1) is a glycoprotein hormone that affects the progression of cancers. However, the potential role of STC-1 in OSCC progression remains to be explored. Here, we aimed to elucidate the role of STC-1 in OSCC. We revealed that STC-1 was highly expressed in OSCC tissues and is correlated with poor patient prognosis. Knockdown of STC-1 significantly suppressed the growth of OSCC cells and restrained glycolysis by reducing glucose consumption, ATP production, and lactate levels. Mechanistically, STC-1 ablation inhibited the PI3K/Akt pathway, reducing the phosphorylation levels of PI3K and Akt. In conclusion, STC-1 depletion restrained OSCC cell growth and glycolysis via PI3K/Akt pathway and has the potential to serve as a therapeutic target for OSCC.

Protein inhibitor of activated signal transducer and activator of transcription 2 is an oncoprotein in oral squamous cell carcinoma and related to cigarette smoking - An in vitro study

Background/purposeOral cancer is one of the most prevalent malignant tumors in Taiwan. Due to the heterogeneity of oral cancer cells, the five-year survival rate of patients is only 50%. Post-translational modifications contribute to protein diversity and directly influence cell functions. The protein inhibitor of activated signal transducer and activator of transcription 2 (PIAS2) is known to undergo post-translational modifications, yet its impact on oral cancer remains unclear. Materials and methodsPIAS2 expression was modulated by transfecting cells with a PIAS2 expression vector or by knocking down PIAS2 using siRNA with low and high PIAS2 expression, respectively. These cells were subjected to invasion, migration, and proliferation assays to evaluate the effects of PIAS2. Changes in genotype, such as epithelial-mesenchymal transition (EMT) markers, were also examined. Additionally, the effect of cigarette smoke condensate (CSC) on PIAS2 expression in oral squamous cell carcinoma (OSCC) cells was investigated. ResultsOverexpression of PIAS2 significantly increased the malignant behaviors of oral cancer cells. In YD38 and SAS cells with low PIAS2 expression, overexpression of PIAS2 enhanced proliferation, invasion, and migration. PIAS2 overexpression also affected EMT gene expression, suppressing E-cadherin and increasing fibronectin expression. Conversely, PIAS2 knockdown in OECM1 and SCC25 cells suppressed malignant behaviors and reversed EMT markers, increasing E-cadherin and decreasing fibronectin expression. Furthermore, a dose-dependent increase in PIAS2 expression was observed when OSCC cells were treated with CSC. ConclusionPIAS2 functions as an oncogene in oral cancer, and cigarette smoking induces PIAS2 expression. Increased PIAS2 levels lead to enhanced malignancy in oral cancer.

M6A-Mediated IRS1 Regulates the Development of Oral Squamous Cell Carcinoma through p53/Line-1 Signaling.

The importance of N6-methyladenosine (m6A) modification in tumorigenesis and progression have been highlighted. This study aimed to investigate the modification of insulin receptor substrate 1 (IRS1) by m6A and its role in oral squamous cell carcinoma (OSCC). Bioinformatics was employed to predict differential genes related to epithelial-mesenchymal transition (EMT) in OSCC. Seventeen pairs of OSCC and paracancerous tissue samples were collected. The impact of IRS1 on OSCC cell growth and EMT was evaluated. The fluctuations in IRS1 enrichment and the involvement of p53/Line-1 were investigated. IRS1 was highly expressed in OSCC. IRS1 silencing decreased OSCC cell proliferation and increased apoptosis. IRS1 silencing hindered EMT by regulating related markers. IRS1 silencing upregulated p53 and downregulated Line-1 ORF1p. The p53 inhibition reversed the effects of IRS1 silencing and induced EMT in OSCC cells. Furthermore, the m6A modification of IRS1 was increased in OSCC cells. IRS1 were positively regulated by the m6A regulators methyltransferase-like 14 (METTL14) and YTH domain-containing protein 1 (YTHDC1). IRS1 bound to YTHDC1, and YTHDC1 knockdown inhibited the IRS1 nuclear export. The obesity-associated protein (FTO) negatively regulated IRS1, and FTO overexpression reversed the IRS1-induced OSCC tumor growth. m6A methylation-mediated IRS1 regulated EMT in OSCC through p53/Line-1. These findings provide potential therapeutic strategies for managing OSCC.

A 5-ALA mediated photodynamic therapy increases natural killer cytotoxicity against oral squamous cell carcinoma cell lines.

Oral squamous cell carcinoma (OSCC) constitutes over 90% of oral cancers, known for its aggressiveness and poor prognosis. Photodynamic therapy (PDT) has emerged as a promising adjuvant therapy and is linked to immunogenic cell death, activating innate and adaptive anti-tumor responses. Natural Killer (NK) cells, key players in malignant cell elimination, have not been extensively studied in PDT. This study evaluates whether PDT increases OSCC cell lines' susceptibility to NK cell cytotoxicity. PDT, using 5-aminolevulinic acid (5-ALA) and LED irradiation, was applied to Ca1 and Luc4 cell lines. Results showed a dose-dependent viability decrease post-PDT. Gene expression analysis revealed upregulation of NK cell-activating ligands (ULBP1-4, MICA/B) and decreased MHC class I expression in Ca1, suggesting increased NK cell susceptibility. Enhanced NK cell cytotoxicity was confirmed in Ca1 but not in Luc4 cells. These findings indicate that PDT may enhance NK cell-mediated cytotoxicity in OSCC, offering potential for improved treatment strategies.