Tongue Squamous Carcinoma Cell Line Research Articles

Antibacterial profile and antiproliferative activities over human tumor cells of new silver(I) complexes containing two distinct trifluoromethyl uracil isomers

New silver(I) complexes of 5-(trifluoromethyl)uracil (5TFMU) and 6-(trifluoromethyl)uracil (6TFMU) isomers were synthesized, characterized, and evaluated as antibacterial and antiproliferative agents. Based on elemental and thermogravimetric analyses, the Ag-5TFMU and Ag-6TFMU species are formulated as AgC5H2F3N2O2 and Ag2C5HF3N2O2, respectively. Infrared and 13C solid-state nuclear magnetic resonance spectroscopies suggest coordination of the trifluoromethyluracil isomers to silver by both nitrogen and oxygen atoms. Confirmation of their structure and connectivity was achieved, in the absence of single crystals of suitable quality, by state-of-the-art structural powder diffraction methods. In Ag-5TFMU, the organic ligand is tridentate and two distinct metal coordination environments are found (linear AgN2 as well as C2v AgO4 geometries), whereas Ag-6TFMU contains a complex polymeric structure with tetradentate dianionic 6TFMU moieties and five distinct AgX2 (X = N, O) fragments, further stabilized by ancillary (longer) Ag…O contacts. These species presented modest activity over Gram-positive and Gram-negative bacterial strains, whereas Ag-6TFMU was active over a set of tumor cells, with the best activity over prostate (PC-3) and kidney cell lines and selectivity indices of 4.6 and 1.3, respectively. On the other hand, Ag-5TFMU was active over all considered tumor cells except MCF-7 (breast cancer). The best activity was found for PC-3 cells, but no selectivity was observed. The Ag-5TFMU and Ag-6TFMU species also reduced the proliferation of tongue squamous cell carcinoma cell lines SCC − 4 and SCC-15. Preliminary biophysical assays by circular dichroism suggest that the Ag-5TFMU complex interacts with DNA by intercalation, an effect not seen in Ag-6TFMU.

Antihypertensive agent losartan promotes tongue squamous cell carcinoma cell proliferation via EGFR/ERK1/2/cyclin D1 signaling axis

ObjectiveTo study the effects of losartan, an angiotensin II receptor blocker, in the SCC4 and SCC25 human tongue squamous cell carcinoma cell lines. MethodsCell proliferation was measured by MTS/PMS activity and trypan blue exclusion assays. The levels of the cell proliferation marker, cyclin D1, were analyzed by western blotting. Apoptosis was assessed by caspase-3 activation and Annexin V-FITC/propidium iodide double staining. Activation of epidermal growth factor receptor (EGFR) and ERK1/2 was validated by western blotting. ResultsModerate concentrations of losartan enhanced the proliferation of SCC4 and SCC25 cells. However, high losartan concentrations induced apoptosis in SCC4 cells. Losartan activated the EGFR/ERK1/2/cyclin D1 signaling axis, which in turn promoted cell proliferation. Afatinib (EGFR inhibitor) and U0126 (ERK1/2 inhibitor) abolished losartan-induced cell proliferation. In contrast, UC2288 (p21 inhibitor) enhanced it. ConclusionsLosartan exhibited dual effects on tongue squamous cell carcinoma cells. Moderate losartan concentrations facilitated cell proliferation, whereas high concentrations induced cytotoxicity in tongue carcinoma cells.

Piperine Enhances the Anticancer Effects of Cisplatin on Tongue Squamous Cell Carcinoma Cell Line by Inducing Cell Apoptosis.

Oral squamous cell carcinoma is ranked as the predominant type of head and neck squamous cell carcinoma, comprising roughly 90% of all oral cancer cases. Natural products have proven to be highly valuable as complementary, or adjunctive in the treatment of cancer. Piperine, a natural compound derived from Piper nigrum, demonstrates anti-proliferative and anti-neoplastic effects across various types of cancer. This study focused on assessing the cytotoxic effect of piperine in conjunction with cisplatin within the OSCC cell line. In this in-vitro study, cultured OSCC cells were divided into four groups: a control group (untreated), a group exposed solely to piperine, a group exposed solely to cisplatin, and a group receiving both piperine and cisplatin. Cell viability was determined by the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide (MTT) assay technique. Additionally, flow cytometric analysis was employed to examine cell cycle progression and apoptosis. Assessment of reactive oxygen species activity, morphological changes, and nuclear area factor measurements were carried out. Expression of the apoptotic regulator Bax was assessed through western blotting analysis. Piperine has cytotoxic and apoptotic effects in a concentration-dependent manner. Piperine in combination with cisplatin exhibited a synergistic effect, resulting in more pronounced inhibition of cell viability in OSCC cells compared to using piperine and cisplatin alone. Piperine and cisplatin for 24 h induced apoptosis strongly by increasing Bax protein and ROS activity. Combining piperine with cisplatin demonstrated a greater effectiveness in triggering apoptosis in OSCC cells compared to using cisplatin alone, allowing for a reduction.

A novel bispecific peptide targeting PD-1 and PD-L1 with combined antitumor activity of T-cells derived from the patients with TSCC

Programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) are key immune checkpoints (ICs) that critically influence immunotherapy. Tumor resistance to single IC-targeting drugs has increased interest in dual-target drugs, which have shown feasibility for cancer treatment. In this study, we aimed to develop dual-target peptide drugs targeting the PD-1/PD-L1 pathway and to evaluate their efficacy compared to functional antibodies in enhancing the cytotoxicity of human T cells against tongue squamous carcinoma cell lines. Through sequence analysis and peptide truncation, we modified a pre-existing peptide named nABPD-1 targeting PD-1. Subsequently, we obtained two novel peptides named nABPD-2 and nABPD-3, with nABPD-2 showing an enhanced affinity for human PD-1 protein compared to nABPD-1. Importantly, nABPD-2 exhibited dual-targeting capability, possessing a high affinity for both PD-L1 and PD-1. Furthermore, nABPD-2 effectively promoted the cytotoxicity of human T cells against tongue squamous carcinoma cell lines, surpassing the efficacy of anti-PD-1 or anti-PD-L1 functional antibodies alone. Considering that nABPD-2 has lower production costs and dose requirements, it can potentially be used in therapeutic applications.

In Vitro Assessment of the Cytotoxic Effect of 5-Fluorouracil, Thymoquinone and their Combination on Tongue Squamous Cell Carcinoma Cell Line.

Tongue cancer is the most prevalent type of oral cancer. Recently, natural compounds have been considered important resources for several anticancer drugs. Thymoquinone (TQ) exhibits a potent anti-cancer effect. 5-Fluorouracil (5-FU) is a chemotherapeutic drug that has been utilized in the treatment of cancer. Recently, combination therapy has gained popularity as a treatment option for patients with cancer. The present study was carried out to assess the cytotoxic effect of 5-Fluorouracil (5-FU), Thymoquinone (TQ), and their combination on tongue squamous cell carcinoma cell line (HNO-97). Tongue carcinoma cell line (HNO-97) was maintained in cultured flasks and the cells were divided into four groups; group Ι: control untreated group, group ΙΙ: HNO-97-treated cells with different concentrations of 5-FU from 0.5 µM/ml to 3µM/ml, group ΙIΙ: HNO-97-treated cells with different concentrations of TQ from 7.25µM/ml to 23.05µM/ml, and group ΙV: HNO-97-treated cells with both 5-FU and TQ in serial concentrations till (IC50) in a dose of 27.44 µM/ml. Determination of the cytotoxic effect of the tested agents on the HNO-97 cell line was done using methyl thiazole tetrazolium assay, nuclear morphometric analysis, microscopic examination, and annexin-v/ propidium iodide staining assay. The findings revealed that the cytotoxic effect of 5-FU, TQ, and their combination on tongue squamous cell carcinoma cell line (HNO-97) was dose-dependent. The microscopic examination revealed that 5-FU, TQ alone, or their combination induced apoptotic cell death. P-value < 0.05 was statistically significant. The combination of 5-FU and TQ produced a marked cytotoxic effect on HNO-97 cells.

CD44 positive cancer stem cells express invasion and metastasis markers: Analysis of three tongue squamous cell carcinoma cell lines

CD44 positive cancer stem cells express invasion and metastasis markers: Analysis of three tongue squamous cell carcinoma cell lines

Evaluation of the Anti-Cancer Effect of Camel Milk on Tongue Squamous Cell Carcinoma Cell Line Using Flow Cytometric Analysis, Nuclear Morphometric Assay, and Western Blotting Technique: An In-Vitro Study

Evaluation of the Anti-Cancer Effect of Camel Milk on Tongue Squamous Cell Carcinoma Cell Line Using Flow Cytometric Analysis, Nuclear Morphometric Assay, and Western Blotting Technique: An In-Vitro Study

In vitro antimetastatic potential of pseudolaric acid B in HSC-3 human tongue squamous carcinoma cell line

ObjectivePseudolaric acid B (PAB) is a novel diterpenoid derived from the traditional Chinese medicinal herb Cortex pseudolaricis that exerts anticancer, anti-inflammatory, and immunomodulatory properties. While the anticancer potential of PAB has been studied, its effects on metastasis have not been well-studied. This study aims to determine the inhibitory effects of PAB on HSC-3 human tongue squamous cell carcinoma (TSCC) cell line. DesignCell viability and soft agar colony formation assays were conducted to assess cellular proliferation and in vitro tumorigenic capacity of TSCC cells, respectively. Additionally, wound healing, transwell migration, and invasion assays were conducted to monitor the aggressive behavior of TSCC cells. Furthermore, Western blotting analysis was conducted to reveal the signaling pathways involved in the modulation of epithelial-mesenchymal transition (EMT). ResultsThe migratory and invasive capacities of HSC-3 cells were suppressed by PAB irrespective of their proliferation states. PAB’s effects on EMT involved upregulation of E-cadherin expression and downregulation of Twist; these were concomitantly accompanied by downregulated phosphorylation of epidermal growth factor receptor (EGFR). ConclusionsPAB suppresses human TSCC in vitro by regulating Twist/E-cadherin through the EGFR signaling pathway. PAB may have potential as a candidate antimetastatic drug for TSCC treatment.

Regulating Lipid Metabolism via Mitochondrial Dynamics in Tongue Squamous Cell Carcinoma Cancer Stem Cells.

Cancer stem cells (CSCs) are a sub-population of cancer cells present in many kinds of malignant tumors that have the potential for self-proliferation and differentiation. These cells have been demonstrated as the main cause of tumor recurrence and metastasis. Strong evidence indicates that CSCs prefer reprogrammed fatty acid β-oxidation over oxidative phosphorylation for sustaining energy supply. Although mitochondrial dynamics participate in the regulation of cancer stemness, the correlation between the inhibition of mitochondrial fission and the regulation of lipid metabolism in CSCs remains poorly understood. The human tongue squamous cell carcinoma (TSCC) cell lines CAL27 and SAS were used to obtain the CSCs by 3D Spheroid Culture. Then,western blot methods, RT-PCR and flow cytometry analysis were used to identify the TSCC CSCs. Next, Immunofluorescence method, transmission electron microscopy detection and western blot methods were used to evaluate the mitochondrial morphology and the quantity of lipid droplets (LDs). Lastly, lipidomic analysis was applied to explored the lipidomic alterations of TSCC CSCs with different mitochondrial morphology. Here, we show that the quantity of lipid droplets containing intracellular triglyceride (TG) can be decreased by regulating mitochondrial morphology. Lipidomic analysis using ultraperformance liquid chromatography-mass spectrometry (UPLC-MS) also compared alterations in lipid metabolites in tongue squamous cell carcinoma (TSCC) CSCs, TSCC cells (non-CSCs), and CSCs with different mitochondrial morphology. Discriminant lipids of statistical significance were successfully annotated, including phosphatidylcholines (PCs), phosphatidylethanolamines (PEs), sphingomyelins (SMs), triacylglycerols (TGs), phosphatidylglycerols (PGs), phosphatidylserines (PSs), lysophosphatidylcholines (LPCs), and lysophosphatidylethanolamines (LPEs). This study provides a deeper insight into the alterations of lipid metabolism associated with TSCC CSCs, non-CSCs and CSCs regulated by mitochondrial dynamics and thus serves as a guide toward novel targeted therapies.

SOX2 promotes a cancer stem cell-like phenotype and local spreading in oral squamous cell carcinoma

Emerging evidence shows that oral squamous cell carcinoma (OSCC) invasiveness can be attributed to a small subpopulation of cancer stem cells (CSCs) in the bulk of the tumor. However, the presence of CSCs in the OSCC close resection margins is still poorly unexplored. Here, we found that BMI1, CD44, SOX2, OCT4, UBE2C, CXCR4 CSCs marker genes are significantly upregulated, while IGF1-R, KLF4, ALDH1A1, CD133, FAM3C are downregulated in the tumor core vs healthy mucosa of 24 patients with OSCC. Among these, SOX2 appears also upregulated in the tumor close margin vs healthy mucosa and this significantly correlates with tumor size and lymph node compromise. In vitro analyses in CAL27 and SCC15 tongue squamous cell carcinoma cell lines, show that SOX2 transient knockdown i) promotes the mesenchymal-to-epithelial transition, ii) smooths the invasiveness, iii) attenuates the 3D tumor sphere-forming capacity, and iv) partially increases the sensitivity to cisplatin treatment. Overall, our study highlights that the OSCC close margins can retain CSC-specific markers. Notably, SOX2 may represent a useful CSCs marker to predict a more aggressive phenotype and a suitable target to prevent local invasiveness.

The Synergistic Cytotoxic Effect of Low-Level Laser Therapy and 5-Aminolevulinic Acid-Mediated Photodynamic Therapy on Tongue Squamous Cell Carcinoma Cell Line

The Synergistic Cytotoxic Effect of Low-Level Laser Therapy and 5-Aminolevulinic Acid-Mediated Photodynamic Therapy on Tongue Squamous Cell Carcinoma Cell Line

MiR-3529-3p from PDGF-BB-induced cancer-associated fibroblast-derived exosomes promotes the malignancy of oral squamous cell carcinoma

AimsThis study aims to explore the role of exosomes from cancer-associated fibroblasts (CAFs) induced by PDGF-BB in promoting the malignancy of oral squamous cell carcinoma (OSCC) and provide new insight into the mechanism of OSCC progression and its treatment.Main methodsExosomes were extracted from human oral mucosa fibroblasts (hOMFs) and CAFs. Differentially expressed miRNAs of exosomes between hOMFs and CAFs were analysed using high-throughput sequencing and self-programmed R software. Cal-27, a human tongue squamous carcinoma cell line, was treated with exosomes. Differentially expressed miRNAs between clinical cancer tissues and adjacent tissues and between hOMF and CAF exosomes were verified by qRT‒PCR. The effect of miR-3529-3p on Cal-27 cells was clarified by overexpressing or knocking down miR-3529-3p in Cal-27 cells. Sample expression and differentially expressed miRNA expression were compared between cancer and paracarcinoma tissues.Key findingsWe found that exosomes from CAFs (CAF-Exos) were internalized by tongue squamous carcinoma cells and promoted their proliferation, migration, invasion, and antiapoptotic effects. MiR-3529-3p was a significant differentially expressed miRNA between CAF-Exos and exosomes from hOMFs (hOMF-Exos). The overexpression of miR-3529-3p promoted proliferation, migration, and invasion and inhibited apoptosis of Cal-27 cells.SignificanceThis study explores the role of PDGF-BB-induced CAFs in promoting malignancy in OSCC. This study will provide new insight into the mechanism of OSCC progression and its treatment.

Novel tetrahydrocurcumin integrated mucoadhesive nanocomposite κ-carrageenan/xanthan gum sponges: a strategy for effective local treatment of oral cancerous and precancerous lesions

Oral cancer is one of the leading causes of death worldwide. Oral precancerous lesions (OPL) are the precursors of oral cancer, with varying degrees of progression. Tetrahydrocurcumin (THC) is a major metabolite of curcumin with superior anticancer properties against various types of cancer. However, THC’s clinical outcome is limited by its poor aqueous solubility. Herein, we developed novel mucoadhesive biopolymer-based composite sponges for buccal delivery of THC, exploiting nanotechnology and mucoadhesion for efficient prevention and treatment of oral cancer. Firstly, THC-nanocrystals (THC-NC) were formulated and characterized for subsequent loading into mucoadhesive composite sponges. The anticancer activity of THC-NC was assessed on a human tongue squamous carcinoma cell line (SCC-4). Finally, the chemopreventive activity of THC-NC loaded sponges (THC-NC-S) was examined in DMBA-induced hamster OPL. The selected THC-NC exhibited a particle size of 532.68 ± 13.20 nm and a zeta potential of −46.08 ± 1.12 mV. Moreover, THC-NC enhanced the anticancer effect against SCC-4 with an IC50 value of 80 µg/mL. THC-NC-S exhibited good mucoadhesion properties (0.24 ± 0.02 N) with sustained drug release, where 90% of THC was released over 4 days. Furthermore, THC-NC-S had a magnificent potential for maintaining high chemopreventive activity, as demonstrated by significant regression in the dysplasia degree and a decline in cyclin D1 (control: 40.4 ± 12.5, THC-NC-S: 12.07 ± 5.2), culminating in significant amelioration after 25 days of treatment. Conclusively, novel THC-NC-S represent a promising platform for local therapy of OPL, preventing their malignant transformation into cancer.

Novel human lymph node-derived matrix supports the adhesion of metastatic oral carcinoma cells

Background3D culture is increasingly used in cancer research, as it allows the growth of cells in an environment that mimics in vivo conditions. Metastases are the primary cause of morbidity and mortality in cancer patients, and solid tumour metastases are mostly located in lymph nodes. Currently, there are no techniques that model the pre-metastatic lymph node microenvironment in vitro. In this study, we prepared a novel extracellular matrix, Lymphogel, which is derived from lymph nodes, mimicking the tumour microenvironment (TME) of metastatic carcinoma cells. We tested the suitability of the new matrix in various functional experiments and compared the results with those obtained using existing matrices.MethodsWe used both commercial and patient-derived primary and metastatic oral tongue squamous cell carcinoma (OTSCC) cell lines. We characterized the functional differences of these cells using three different matrices (human uterine leiomyoma-derived Myogel, human pre-metastatic neck lymph node-derived Lymphogel (h-LG), porcine normal neck lymph node-derived Lymphogel (p-LG) in proliferation, adhesion, migration and invasion assays. We also performed proteomic analyses to compare the different matrices in relation to their functional properties.ResultsOTSCC cells exhibited different adhesion and invasion patterns depending on the matrix. Metastatic cell lines showed improved ability to adhere to h-LG, but the effects of the matrices on cell invasion fluctuated non-significantly between the cell lines. Proteomic analyses showed that the protein composition between matrices was highly variable; Myogel contained 618, p-LG 1823 and h-LG 1520 different proteins. The comparison of all three matrices revealed only 120 common proteins. Analysis of cellular pathways and processes associated with proteomes of each matrix revealed similarities of Myogel with h-LG but less with p-LG. Similarly, p-LG contained the least adhesion-related proteins compared with Myogel and h-LG. The highest number of unique adhesion-related proteins was present in h-LG.ConclusionsWe demonstrated that human pre-metastatic neck lymph node-derived matrix is suitable for studying metastatic OTSCC cells. As a whole-protein extract, h-LG provides new opportunities for in vitro carcinoma cell culture experiments.

Hyaluronic acid/chitosan-coated poly (lactic-co-glycolic acid) nanoparticles to deliver single and co-loaded paclitaxel and temozolomide for CD44+oral cancer cells

Oral cancer has a poor survival rate despite comprehensive therapy. Current treatments result in acute side effects and fail to eliminate an aggressive group of cells overexpressing CD44. Such cells are capable of tumour initiating, self-renewal, invasion and metastasis, resulting in tumour relapse and resistance. This study aims to synthesise and characterise hyaluronic acid/chitosan-coated poly (lactic-co-glycolic acid) nanoparticles and assess their effectiveness in delivering Paclitaxel and Temozolomide to human tongue squamous cell carcinoma cell line that expresses high CD44 levels, in terms of cell cytotoxicity and apoptosis. This study also assesses the coordinated administration of Paclitaxel and Temozolomide and whether they exhibit significant synergistic cell inhibition effects with reduced introduced drug concentration if co-delivered simultaneously. Nanoparticles were synthesised with solvent evaporation method and characterised to assess their size, homogeneity, and zeta potential. Cell viability assay and real-time cell analysis were performed to examine the cell inhibitory effect of the drug-loaded nanoparticles. Cell apoptosis and cell cycle alteration were detected, and reactive oxygen species induction, mitochondrial membrane potential, and expressed genes associated with cell inhibition and death were evaluated. The synthesised nanoparticles had a nano-sized diameter of 260.40±11.54 nm, a positive zeta potential of +14.31±1.37 mV and a low polydispersity index value of 0.15±0.03. Paclitaxel, Temozolomide, and their combination have inhibited cell proliferation with half maximal inhibitory concentrations of 4 nM, 1000 μM and 2nM:300 μM, respectively. Compared to free drugs, the single-loaded and co-loaded drugs induced more cytotoxicity. Paclitaxel and Temozolomide showed a considerable synergistic inhibitory effect which was discovered to be more significant when the drugs were loaded in the nanoparticles. Drug-loaded nanoparticles were verified to induce higher cell apoptosis rates, cell proportion arrested at the S-phase of the cell cycle, reactive oxygen species generation, mitochondrial collapse and expression of genes associated with cellular inhibition and death than free drugs. These results demonstrate that the established nanoparticles could be a potential candidate for oral cancer therapy since they could deliver and improve the efficacy of single and dual drugs against oral cancer cells.

In vitro evaluation of photon and carbon ion radiotherapy in combination with cisplatin in head and neck squamous cell carcinoma cell lines.

Heavy ion radiotherapy, such as carbon ion radiotherapy (CIRT), has multiple advantages over conventional photon therapy. Cisplatin, as a classic anti-tumor drugs, has been tested and discovered as a photon radiosensitizer in several cell lines, including head and neck squamous cell carcinoma (HNSCC). Hence, the aim of our study is to evaluate whether cisplatin can sensitize CIRT towards HNSCC cell lines in vitro. Human nasopharyngeal carcinoma cell line CNE-2, human tongue squamous carcinoma cell line TCA 8113 and human hypopharynx squamous carcinoma cell line FADU were all irradiated with photon beam of 2, 4, 6, 8 Gy (physical dose) and carbon ion beam of 1, 2, 3, 4 Gy (physical dose) and treated with cisplatin. Cell survival was assessed by clonogenic survival assay. CIRT showed significantly stronger cytotoxic effect than standard photon radiotherapy. The relative biological effectiveness (RBE) of carbon ion beam at 10% survival ( ) was calculated 3.07 for CNE-2, 2.33 for TCA 8113 and 2.36 for FADU. Chemoradiotherapy (both photon radiotherapy and CIRT) was more effective than radiotherapy alone. In vitro sensitizer enhancement ratios (SERs) of cisplatin in CNE-2, TCA 8113 and FA DU cell lines after photon irradiation were 1.33, 1.14 and 1.21, while after carbon ion irradiation were 1.02, 1.00 and 0.96, showed that cisplatin sensitized photon irradiation but showed no sensitization effect in carbon ion irradiation in all tested cell lines. In conclusion, high linear energy transfer (LET) CIRT was more effective than photon irradiation to prevent the proliferation of HNSCC cell lines. Additional treatment with cisplatin could sensitize photon irradiation but showed no effect on carbon ion irradiation.

Abstract 4835: EP4 increases the mitochondrial respiration and promotes cell migration in oral cancer

Abstract Introduction: EP4 is one of the prostaglandin E2 (PGE2) receptors. We previously reported that EP4 promoted cell migration via Ca2+ signaling, however the underlying mechanism has remained unclear. In Ca2+ signaling, Store-operated Ca2+entry (SOCE) is a major mechanism of Ca2+ import from the extracellular to the intracellular space. Orai1, one of the selective Ca2+ channels, plays an important role in SOCE. We focused on the correlation with EP4 and Orai1. Additionally, we found that EP4 promoted the phosphorylation of calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) and AMP-activated protein kinase (AMPK) located downstream of CaMKK2, i.e., cell energy regulators. AMPK activation can control positively or negatively the cellular adenosine triphosphate (ATP) supply. Therefore, we investigated how EP4 regulated the mitochondrial function via Ca2+ and promoted the cell migration in oral cancer cells. Materials and Methods: HSC-3, human tongue squamous cell carcinoma cell line was used. ONO-AE1-437 was used as EP4 agonist. HSC-3 cells were transduced with Orai1 shRNA, and control shRNA using lentivirus. The migration ability was evaluated by scratch assay. Measurement of intracellular Ca2+ concentration was measured using Fura-2. Immunoprecipitation was performed to evaluate the interaction between EP4 and Orai1. XF Cell Mito Stress Test and XF Real-Time ATP Rate Assay were performed to evaluate the mitochondrial aspiration and the ATP production using Extracellular Flux Analyzer. Results: Scratch assay showed EP4 promoted cell migration in oral cancer cells (n=4, p&amp;lt;0.05). In contrast, Orai1 knockdown negated EP4-induced cell migration. EP4 rapidly increased the intracellular Ca2+ concentration, while Orai1 knockdown negated EP4-indued Ca2+ increase (n=4, p&amp;lt;0.05). Immunoprecipitation showed that EP4 was colocalized and formed complexes with Orai1 (n=4, p&amp;lt;0.05). These results indicated that EP4 promoted the cell migration via Ca2+ signaling through Orai1. EP4 increased the maximal respiration 3h after the stimulation (n=6, p&amp;lt;0.05). ATP production rate shifted mitoATP dominant. These data indicated that EP4 increased the mitochondrial function and the respiratory capacity, potentially regulating its energy supply. These results demonstrated that EP4 promoted mitochondria respiration and then increased the energy production from mitochondria in oral cancer cells. Conclusion: We concluded that EP4 regulated the mitochondrial function via Ca2+ through Orai1 and promoted the cell migration in oral cancer cells. Citation Format: Rina Nakakaji, Masanari Umemura, Kohei Osawa, Soichiro Ishikawa, Kenji Mitsudo, Yoshihiro Ishikawa. EP4 increases the mitochondrial respiration and promotes cell migration in oral cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4835.

Cholesterol depletion affects caveolin-1 expression, migration and invasion of oral tongue squamous cell carcinoma cell lines

IntroductionCholesterol is a key lipid molecule within cell membranes. This is especially true in cavelolas, invaginated membrane nanodomains, which present the protein caveolin-1 (CAV-1). It is important to note that this structure is involved in many cell signalling pathways. Additionally, high cholesterol is seen in different tumor types but little is known in regards to oral tongue squamous cell carcinoma (OTSCC). The aim of this study was to evaluate the influence of cholesterol depletion on primary (SCC-25) and metastatic (HSC-3) OTSCC cell lines. Materials and methodsCell membrane fluidity, cell viability, gene and protein expression of CAV-1 and of epithelial-mesenchymal transition (EMT) markers, cell migration in Myogel and invasion-myoma assay were evaluated after cholesterol depletion with methyl-β-cyclodextrin (MβCD - 7.5, 10 or 15 mM) ResultsDecreased cell viability and increased membrane fluidity of SCC-25 cells was seen with cholesterol depletion but cell viability was less affected and there was no effect on membrane fluidity in HSC-3. Cholesterol depletion also decreased CAV-1 at 6 h but increased it after 24 h.; both epithelial and mesenchymal EMT genes were upregulated after 6 h, followed by downregulation at 24 h in SCC-25. In HSC-3, CAV-1 was downregulated, and E-cadherin gene (ECAD) was upregulated at 6 h. Only the protein β-catenin in SCC-25 was affected, and cell migration of both cell lines was decreased, affecting SCC-25 more intensely. The invasive capacity within human myoma organotypic model was increased in SCC-25 and decreased in HSC-3. ConclusionCholesterol depletion affects CAV-1 and ECAD inversely. This affect also depends on cell type since the invasive capacity was augmented in primary cells while decreased in metastatic cells.

Evaluation of the cytotoxic, anti-proliferative, anti-metastatic and pro-apoptotic effect of aqueous leaf extract of Annona muricata on oral tongue squamous cell carcinoma cell line (SCC-15): An in vitro study.

Oral cancer still represents the leading cause of mortality in India. Due to the drawbacks of current treatment options, a safe, low-cost therapy is the need of the hour. Recently, novel plant extracts with anti-cancer properties have gained greater attention. One among them is Annona muricata and its leaf extract, which has been studied for its anti-cancer effect against various cancers. However, studies on oral cancer cells are very much limited and hence the study. To evaluate the cytotoxic, anti-proliferative, anti-metastatic and pro-apoptotic effect of aqueous leaf extract of Annona muricata (ALEAM) against SCC-15 cell lines through in vitro assays. In vitro assays such as MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide], colony formation and wound healing assays were performed. Furthermore, to evaluate the underlying mechanism, gene and protein expression analysis of apoptotic/anti-apoptotic marker genes Bax, P53 and Bcl2, were done using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analysis. Student's t-test has been performed for analysis of experimental data. The results showed that ALEAM exhibited significant cytotoxic activity in a dose-dependent manner as well as inhibited colony formation and cell migration. The pro-apoptotic properties were affirmed by a highly significant drop in Bcl-2 gene expression and a highly significant rise in P53 and Bax genes in the study group compared to the control (P < 0.05). The current study provides evidence that ALEAM has the potential to be developed as a novel anti-cancer drug for the treatment of SCC after further clinical studies.

A Novel Tongue Squamous Cell Carcinoma Cell Line Escapes from Immune Recognition due to Genetic Alterations in HLA Class I Complex.

Immune checkpoint inhibitors (ICI) have made progress in the field of anticancer treatment, but a certain number of PD-L1 negative OSCC patients still have limited benefits from ICI immuno-therapy because of primary immune evasion due to immunodeficiency. However, in existing human OSCC cell lines, cell models that can be used to study immunodeficiency have not been reported. The objective of this study was to establish a PD-L1 negative OSCC cell line, profile whether the presence of mutated genes is associated with immune deficiency, and explore its influence on the immune recognition of CD8+ T cells in vitro. Here, we established a novel tongue SCC cell line (WU-TSC-1), which escapes from immune recognition by antigen presentation defects. This cell line was from a female patient who lacked typical causative factors. The expression of PD-L1 was negative in the WU-TSC-1 primary tumor, transplanted tumor, cultured cells and lipopolysaccharide stimulation. Whole exome sequencing (WES) revealed that WU-TSC-1 harbored missense mutations, loss of copy number and structural variations in human leukocyte antigen (HLA) class I/II genes. The tumor mutation burden (TMB) score was high at 292.28. In addition, loss of heterozygosity at beta-2-microglobulin (B2M)-a component of all HLA class I complex allotypes-was detected. Compared with the commonly used OSCC cell lines, genetic alterations in HLA class I and B2M impeded the proteins' translation and inhibited the activation and killing effect of CD8+ T cells. In all, the WU-TSC-1 cell line is characterized by genetic variations and functional defects of the HLA class I complex, leading to escape from recognition by CD8+ T cells.