Squamous Carcinoma Cell Lines Research Articles

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.

∆Np63α inhibits Rac1 activation and cancer cell invasion through suppression of PREX1

ΔNp63α, a member of the p53 family of transcription factors, plays a critical role in maintaining the proliferative potential of stem cells in the stratified epithelium. Although ΔNp63α is considered an oncogene and is frequently overexpressed in squamous cell carcinoma, loss of ΔNp63α expression is associated with increased tumor cell invasion and metastasis. We recently identified a ΔNp63α/miR-320a/PKCγ signaling axis that regulates cancer cell invasion by inhibiting phosphorylation of the small GTPase Rac1, a master switch of cell motility that positively regulates cell invasion in multiple human cancers. In this study, we identified a novel mechanism by which ΔNp63α negatively regulates Rac1 activity, by inhibiting the expression of the Rac-specific Guanine Exchange Factor PREX1. ΔNp63α knockdown in multiple squamous cell carcinoma cell lines leads to increased Rac1 activation, which is abrogated by treatment with the Rac1 inhibitor NSC23766. Furthermore, ΔNp63α negatively regulates PREX1 transcript and protein levels. Using a Rac-GEF activation assay, we also showed that ΔNp63α reduces the levels of active PREX1. The inhibition of the PREX1-Rac1 signaling axis by ΔNp63α leads to impaired cell invasion, thus establishing the functional relevance of this link. Our results elucidated a novel molecular mechanism by which ΔNp63α negatively affects cancer cell invasion and identifies the ΔNp63α/Rac1 axis as a potential target for metastasis.

Chemopreventive Efficacy of Sulindac Sulfone as a Selective Apoptotic Antineoplastic Drug in Human Head and Neck Squamous Cell Carcinoma Cell Lines: A Systematic Review.

Sulindac sulfone, an active metabolite of sulindac, a non-steroidal anti-inflammatory drug, has good anti-inflammatory potential. The antineoplastic effect of sulindac sulfone is mediated through a cyclooxygenase inhibitory mechanism, followed by apoptosis and inhibition of cell proliferation. Mounting studies have explored the anti-neoplastic effect of sulindac sulfone in various types of cancers in a dose-dependent manner. In this backdrop, we have conducted a systematic review to evaluate the efficacy and dose of sulindac sulfone as an anti-neoplastic agent in human head and neck squamous cell carcinoma cell lines (HNSCCs). In this study, we used a systematic literature review approach, and articles were searched in PubMed, and Medline with the keywords "sulindac sulfone," "anti-neoplastic activity," "chemopreventive," and "head and neck squamous cell carcinoma". A hand-search of journals was also performed. Articles were reviewed and analyzed. The analysis reveals that, based on the in vitro studies on various tumor models, the optimum concentration of sulindac sulfone which elicits anti-neoplastic effects is 200-800 µM. The anti-neoplastic effect is mediated through inhibition of cell proliferation and apoptosis. The results of our systematic review show that the anti-neoplastic activity of pharmacologic Sulindac sulfone is part of its dose-dependent activity, which can be safely employed in the therapy for human HNSCCs and would be responsible for a beneficial outcome of the treatment.

An AI-assisted integrated, scalable, single-cell phenomic-transcriptomic platform to elucidate intratumor heterogeneity against immune response.

We present a novel framework combining single-cell phenotypic data with single-cell transcriptomic analysis to identify factors underpinning heterogeneity in antitumor immune response. We developed a pairwise, tumor-immune discretized interaction assay between natural killer (NK-92MI) cells and patient-derived head and neck squamous cell carcinoma (HNSCC) cell lines on a microfluidic cell-trapping platform. Furthermore we generated a deep-learning computer vision algorithm that is capable of automating the acquisition and analysis of a large, live-cell imaging data set (>1 million) of paired tumor-immune interactions spanning a time course of 24 h across multiple HNSCC lines (n = 10). Finally, we combined the response data measured by Kaplan-Meier survival analysis against NK-mediated killing with downstream single-cell transcriptomic analysis to interrogate molecular signatures associated with NK-effector response. As proof-of-concept for the proposed framework, we efficiently identified MHC class I-driven cytotoxic resistance as a key mechanism for immune evasion in nonresponders, while enhanced expression of cell adhesion molecules was found to be correlated with sensitivity against NK-mediated cytotoxicity. We conclude that this integrated, data-driven phenotypic approach holds tremendous promise in advancing the rapid identification of new mechanisms and therapeutic targets related to immune evasion and response.

Mitochondrial antioxidants in normal oral epithelial and oral squamous cell carcinoma cell lines

Mitochondrial antioxidants play an important role in regulation of oral cancer progression. In our study we profiled the expression levels of various mitochondrial antioxidants such as reduced glutathione, lipid peroxides, mitochondrial catalase, mitochondrial superoxide dismutase 2 (SOD2), and mitochondrial glutaredoxin 2( GLRX2) in normal oral epithelial cell line and oral squamous cell carcinoma cell (OSCC) line. Our comparative study on these cell lines using UV-Vis Spectrophotometry and Immunoblotting reveal there is an altered profile of the mitochondrial antioxidants in oral squamous cell carcinoma. While the expression levels of mitochondrial Catalase, mitochondria Lipid Peroxide, mitochondrial Superoxide Dismutase 2 and mitochondrial Glutaredoxin 2 decrease in oral squamous cell carcinoma cell line as compared to oral epithelial cell line, the levels of reduced glutathione increase. Our results indicate there is a complex interplay of mitochondrial antioxidants in regulation of oral squamous cell carcinoma.

Cell-SELEX and application research of a DNA aptamer against esophageal squamous cell carcinoma (ESCC) cell line TE-1.

Esophageal cancer is a common cancer with high morbidity and mortality that severely threatens the safety and quality of human life. The strong metastatic nature of esophageal cancer enables it to metastasize more quickly and covertly, making it difficult for current diagnostic and treatment methods to achieve efficient early screening, as well as timely and effective treatment. As a promising solution, nucleic acid aptamers, a kind of special single-stranded DNA or RNA oligonucleotide selected by the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) technology, can specifically bind with different molecular targets. In this paper, random DNA single-stranded oligonucleotides were used as the initial library. Using TE-1 cells and HEEC cells as targets, specific binding sequences were selected by 15 rounds of the cell-SELEX method, and the aptamer sequence that binds to TE-1 cells with the most specificity was obtained and named Te4. The Te4 aptamer was further validated for binding specificity, binding affinity, type of target, in vitro cytotoxicity when conjugated with DOX(Te4-DOX), and in vivo distribution. Results of in vitro validation showed that Te4 has outstanding binding specificity with a Kd value of 51.16 ± 5.52 nM, and the target type of Te4 was preliminarily identified as a membrane protein. Furthermore, the cytotoxicity experiment showed that Te4-DOX has specific cytotoxicity towards cultured TE-1 cells. Finally, the results of the in vivo distribution experiment showed that the Te4 aptamer is able to specifically target tumor regions in nude mice, showing great potential to be applied in future diagnosis and targeted therapy of esophageal cancer.

The impact of altering the concentration of coffee constituents on their anticancer effect on oral squamous cell carcinoma cell line – in vitro study

The impact of altering the concentration of coffee constituents on their anticancer effect on oral squamous cell carcinoma cell line – in vitro study

The effects of basil (Ocimum basilicum) leaf extract on Ca9-22 oral cancer cells

Basil (Ocimum basilicum), as a prominent member of the Lamiaceae family, is known to possess anti-inflammatory, anti-oxidant, and anti-cancer properties. This study investigated the inhibitory effect of basil extract on oral cancer cells. Basil leaves were dried and extracted with ethanol. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used to assess the cytotoxic effect of basil extract (12.5, 25, 50, 100, 200, 500, and 1000 ?g/mL) on Ca9- 22, a human gingival squamous carcinoma cell line, after 24, 48, and 72 h. Gene expression of cell cycle regulators (cyclin D1, cyclin-dependent kinase 4 (CDK4), p21, p53) and inflammatory markers (cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), tumor necrosis factor-alpha (TNF-?), interleukin (IL)-1? and IL-6) was analyzed using real-time polymerase chain reaction (RT-PCR). Additionally, these markers were measured in culture supernatants via enzyme-linked immunosorbent assay (ELISA). The MTT assay revealed a concentration-dependent reduction in cell viability, with IC50 values of 350 ?g/mL for Ca9-22 cells. RT-PCR analysis revealed that treated cells exhibited downregulation of cyclin D1 and CDK4, along with upregulation of p21 and p53, compared to control Ca9-22 cells, which were only exposed to nutrient medium. These changes were observed at both mRNA and protein levels. Inflammatory genes (COX-2, iNOS, TNF-?, IL-1?, IL-6) were significantly decreased at both mRNA and protein levels. Basil extract exerts cytotoxic effects on oral cancer cells by inhibiting cell cycle progression and inflammatory mediators. These findings point to the potential use of O. basilicum extract as a therapeutic agent against oral cancer.

Suppression of KLF5 basal expression in oral carcinoma-derived cells through three intact CREB1-binding sites in the silencer region

ObjectivesKrüppel-like factor (KLF)5, which is overexpressed in carcinomas such as oral cancer, inhibits epidermal differentiation. KLF5 induces dedifferentiation of carcinoma cells, which effectuates carcinoma progression; nevertheless, the regulatory mechanism affecting the transcription of the KLF5 gene remains ambiguous. MethodsTranscriptional activity of the KLF5 silencer, specifically the 425-bp region (425-region), was examined using reporter assays. An additional analysis was conducted to assess the impact of the minimal essential region (MER) of KLF5 on its basal expression. The affinity of cAMP responsive element binding protein 1 (CREB1) for three potential CREB1-binding sites in the 425-region was analyzed using DNA pull-down and quantitative chromatin immunoprecipitation assays. Reporter assays employing a human oral squamous carcinoma cell line, HSC2, transfected with small interfering RNA or complementary DNA for CREB1, were performed to investigate the effect of CREB1 binding sites on MER activity. ResultsThe 425-region exhibited no transcriptional activity and suppressed MER transcriptional activity. This region encodes three putative CREB1-binding sites, and CREB1 demonstrated equal binding affinity for all three sites. The deletion of each of these binding sites reduced CREB1 precipitation and enhanced MER activity. Endogenous CREB1 knockdown and overexpression elevated and reduced MER activity, respectively, at the intact sites. Conversely, site deletion hampered and improved MER activity upon CREB1 knockdown and overexpression, respectively. ConclusionsSuppression of KLF5 basal expression via CREB1 binding to the 425-region requires all three CREB1-binding sites to remain intact in oral carcinoma cells. Consequently, deletion of the CREB1-binding site relieves suppression of KLF5 basal expression.

OVEREXPRESSION OF CYCLIN D1 IN ORAL CANCER INCREASES TPF CHEMOTHERAPEUTIC DRUGS VIA ACTIVATING THE CASPASE-3 PATHWAY

Previous studies have indicated that induction chemotherapy can limit the possibility of early lesion eradication and lessen the severity of globally advanced tumors. This study aimed to ascertain if cyclin D1 expression in OSCC patients who were qualified for TPF induction chemotherapy might be regarded as a valid prognostic indicator for long-term outcomes. This study aimed to determine whether or not there was a connection between OSCC cell intervention and the production of cyclin D1 and chemosensitivity to TPF medicines through the apoptotic mechanism. The current work used immunohistochemistry to determine the expression of cyclin D1 in various tissues. To ascertain the survival rate of 232 people diagnosed with locally advanced oral squamous cell carcinoma (OSCC), the study utilized the log-rank test and Kaplan-Meier analysis. The participants in this historical clinical trial were observed for a mean duration of five years. Cytotoxicity assays were employed to assess the therapeutic effectiveness of TPF chemotherapy drugs. The activity of caspase-3 and PARP was evaluated in the HB96, CAL27, and HN30 cell lines following cyclin D1 inhibition, respectively. Long-term clinical outcomes were significantly better for patients with OSCC whose cancer cells expressed low amounts of cyclin D1 than those whose cells expressed high protein levels. Time to initial illness occurrence, time to initial local recurrence, time to mortality, and overall survival were among the metrics evaluated. The groups with low and high expression levels of cyclin D1 showed significantly different survival rates for disease-free survival, overall survival (OS), DMFS, local recurrence-free survival, and local recurrence-free survival (p0.001, 0.003, 0.004, and 0.001, respectively). Patients with cN2 oral squamous cell carcinoma (OSCC) with higher cyclin D1 expression had better distant metastasis-free survival (OS, P=0.024; DMFS, P=0.024) and overall survival (OS, P=0.024; DMFS, P=0.024) with TPF induction chemotherapy. However, patients with cN2 OSCC and low cyclin D1 expression did not show this survival advantage (P=0.024). Research has shown that oral squamous cell carcinoma (OSCC) is more sensitive to TPF-based chemotherapeutic drugs using caspase-3-mediated apoptosis that occurs when cyclin D1 expression rises. Based on these results, TPF induction chemotherapy may provide longer-term benefits than traditional treatment approaches for patients with cN2 OSCC and high cyclin D1 expression. Through a caspase-3-dependent mechanism, oral squamous cell carcinoma (OSCC) cell lines become more susceptible to TPF chemotherapeutic drugs when cyclin D1 is overexpressed.

Dissection of an impact of VDR and RXRA on the genomic activity of 1,25(OH)2D3 in A431 squamous cell carcinoma

BackgroundHuman skin is the natural source, place of metabolism, and target for vitamin D3. The classical active form of vitamin D3, 1,25(OH)2D3, expresses pluripotent properties and is intensively studied in cancer prevention and therapy. To define the specific role of vitamin D3 receptor (VDR) and its co-receptor retinoid X receptor alpha (RXRA) in genomic regulation, VDR or RXRA genes were silenced in the squamous cell carcinoma cell line A431 and treated with 1,25(OH)2D3 at long incubation time points 24 h/72 h. Extending the incubation time of A431 WT (wild-type) cells with 1,25(OH)2D3 resulted in a two-fold increase in DEGs (differentially expressed genes) and a change in the amount of downregulated from 37% to 53%. VDR knockout led to a complete loss of 1,25(OH)2D3-induced genome-wide gene regulation at 24 h time point, but after 72 h, 20 DEGs were found, of which 75% were downregulated, and most of them belonged to the gene ontology group “immune response”. This may indicate the existence of an alternative, secondary response to 1,25(OH)2D3. In contrast, treatment of A431 ΔRXRA cells with 1,25(OH)2D3 for 24 h only partially affected DEGs, suggesting RXRA-independent regulation. Interestingly, overexpression of classic 1,25(OH)2D3 targets, like CYP24A1 (family 24 of subfamily A of cytochrome P450 member 1) or CAMP (cathelicidin antimicrobial peptide) was found to be RXRA-independent. Also, immunofluorescence staining of A431 WT cells revealed partial VDR/RXRA colocalization after 24 h and 72 h 1,25(OH)2D3 treatment.Comparison of transcriptome changes induced by 1,25(OH)2D3 in normal keratinocytes vs. cancer cells showed high cell type specific expression pattern with only a few genes commonly regulated by 1,25(OH)2D3. Activation of the genomic pathway at least partially reversed the expression of cancer-related genes, forming a basis for anti-cancer activates of 1,25(OH)2D3. In summary, VDR or RXRA independent genomic activities of 1,25(OH)2D3 suggest the involvement of alternative factors, opening new challenges in this field.

Biological Synthesis of Silver Nanoparticles Using Lactobacillus Probiotic Bacterium and Evaluation of Their Cytotoxicity Against Oral Squamous Cell Carcinoma Cell Line: AgNPs Cytotoxicity Against Squamous Cell Carcinoma

Background: The applications of nanotechnology have greatly increased in the recent years. Nanotechnology can be used for diagnosis and treatment of many conditions in medicine and dentistry. The aim of this paper is assessment the cytotoxicity of silver nanoparticles (AGNPs) synthesized employing Lactobacillus acidophilus against human oral squamous cell carcinoma (OSCC) cell line. Materials and Methods: In this in vitro, experimental study, AgNPs were biologically synthesized by using L. acidophilus, and characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible (UV-V) spectroscopy and Fourier-transform infrared (FTIR) spectroscopy. The methyl thiazolyl tetrazolium (MTT) test was performed to assess the cytotoxic effects of AgNPs in 3.125, 6.25, 12.5, 25, 50, and 100 μg/mL concentrations within 24 hours. Results: Synthesis of AgNPs was confirmed by visual perception of dark brown color variation (from achromatic) and maximum UV-V absorption at 428 nm. TEM and SEM indicated the spherical form of AgNPs with a median size of 397 nm. FTIR spectroscopy showed the presence of functional groups from the cells involved in the reduction process. The MTT assay indicated that the biosynthesized nanoparticles made a decrease of cell livability in a concentration dependent method. Conclusion: AgNPs produced by Lactobacillus acidophilus have the potential to inhibit OSCC cell line.

Multifaceted approach toward mapping out the anticancer properties of small molecules via invitro evaluation on melanoma and nonmelanoma skin cancer cells, and in silico target fishing.

Melanoma and nonmelanoma skin cancers are among the most prevalent and most lethal forms of skin cancers. To identify new lead compounds with potential anticancer properties for further optimization, invitro assays combined with in-silico target fishing and docking have been used to identify and further map out the antiproliferative and potential mode of action of molecules from a small library of compounds previously prepared in our laboratory. From screening these compounds invitro against A375, SK-MEL-28, A431, and SCC-12 skin cancer cell lines, 35 displayed antiproliferative activities at the micromolar level, with the majority being primarily potent against the A431 and SCC-12 squamous carcinoma cell lines. The most active compounds 11 (A431: IC50 = 5.0 μM, SCC-12: IC50 = 2.9 μM, SKMEL-28: IC50 = 4.9 μM, A375: IC50 = 6.7 μM) and 13 (A431: IC50 = 5.0 μM, SCC-12: IC50 = 3.3 μM, SKMEL-28: IC50 = 13.8 μM, A375: IC50 = 17.1 μM), significantly and dose-dependently induced apoptosis of SCC-12 and SK-MEL-28 cells, as evidenced by the suppression of Bcl-2 and upregulation of Bax, cleaved caspase-3, caspase-9, and PARP protein expression levels. Both agents significantly reduced scratch wound healing, colony formation, and expression levels of deregulated cancer molecular targets including RSK/Akt/ERK1/2 and S6K1. In silico target prediction and docking studies using the SwissTargetPrediction web-based tool suggested that CDK8, CLK4, nuclear receptor ROR, tyrosine protein-kinase Fyn/LCK, ROCK1/2, and PARP, all of which are dysregulated in skin cancers, might be prospective targets for the two most active compounds. Further validation of these targets by western blot analyses, revealed that ROCK/Fyn and its associated Hedgehog (Hh) pathways were downregulated or modulated by the two lead compounds. In aggregate, these results provide a strong framework for further validation of the observed activities and the development of a more comprehensive structure-activity relationship through the preparation and biological evaluation of analogs.

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.

Targeting Fatty Acid Amide Hydrolase Counteracts the Epithelial-to-Mesenchymal Transition in Keratinocyte-Derived Tumors.

The endocannabinoid system regulates physiological processes, and the modulation of endogenous endocannabinoid (eCB) levels is an attractive tool to contrast the development of pathological skin conditions including cancers. Inhibiting FAAH (fatty acid amide hydrolase), the degradation enzyme of the endocannabinoid anandamide (AEA) leads to the increase in AEA levels, thus enhancing its biological effects. Here, we evaluated the anticancer property of the FAAH inhibitor URB597, investigating its potential to counteract epithelial-to-mesenchymal transition (EMT), a process crucially involved in tumor progression. The effects of the compound were determined in primary human keratinocytes, ex vivo skin explants, and the squamous carcinoma cell line A431. Our results demonstrate that URB597 is able to hinder the EMT process by downregulating mesenchymal markers and reducing migratory potential. These effects are associated with the dampening of the AKT/STAT3 signal pathways and reduced release of pro-inflammatory cytokines and tumorigenic lipid species. The ability of URB597 to contrast the EMT process provides insight into effective approaches that may also include the use of FAAH inhibitors for the treatment of skin cancers.

Phytochemical analysis of carotenoid profile in Mentha piperita and Artemisia vulgaris: cytotoxicity in tumoral cells and evaluation of plasmid DNA cleavage

ABSTRACT Several medicinal plants have been administered to cancer patients attributed to their anticarcinogenic and chemoprotective properties, in addition to lower toxicity compared to traditional therapies. The aim was to investigate the antioxidant properties and carotenoid composition of aqueous extracts of Mentha piperita or Artemisia vulgaris which were previously found to exert beneficial effects on human health through diet. aqueous extracts exhibited potent antioxidant activity. A diversity of carotenoids was identified in these extracts using HPLC-PDA-MS/MS. Both extracts contained predominantly all-trans-lutein as the main component within this class. In order to investigate antioxidant properties, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) techniques were used. The (3–4,5 dimethylthiazol-2, 5 diphenyl tetrazolium bromide) (MTT) and Crystal Violet assays assessed cellular cytotoxicity. Assessments of presence of reactive species were carried out following exposure of oral squamous cell carcinoma cell line (SCC-4) to various aqueous extracts of M piperita or A vulgaris utilizing dichlorofluorescein diacetate (DCFH-DA) and nitric oxide (NO) assays. Exposure to these extracts induced severe cytotoxic effects, which led to investigation of the biochemical and molecular mechanisms underlying this observed effect. Data demonstrated that both solutions induced oxidative stress and DNA damage, especially at higher concentrations using agarose gel subjected to electrophoresis. It is known that exposure to excess amounts of antioxidants results in a prooxidant effect which is beneficial in cancer therapy. Further, the extracts were found to reduce viability of SCC-4 in culture, indicating that this antitumoral activity may be of therapeutic importance and requires further study.

Abstract C122: The impact of the short-chain fatty acids on viability, motility and migration of oral squamous cell carcinoma cell line

Abstract Objectives. Oral squamous cell carcinoma (OSCC) is one of the 10 most common cancers worldwide, with a 5-year relative survival rate of 68%. Since the mechanisms of OSCC in oncogenesis are multifactorial, the development of novel targeted therapies is limited. Short-chain fatty acids (SCFA), i.e. butyrate, acetate, and propionate, are oral microbial products that can potentially inhibit cell growth, proliferation and migration of cancer cells, and may represent an alternative treatment for OSCC as it has not previously evaluated. Here, we measured the impact of SCFA treatment on viability and migration of OSCC cell lines. Methods. OSCC cells were cultured in RPMI-1640 medium supplemented with 10% fetal bovine serum. We performed a cytotoxicity assay with Alamar blue to determine the half-maximal inhibitory concentration (IC50) of the SCFA treatment. Cells were treated with butyrate, acetate, and propionate in concentrations (1:2 dilution factor) starting at 125mM, 500mM, and 125mM, respectively, for 24, 48 and 72 hours. To determine the effects of SCFA on cell migration and motility, we performed a wound-healing assay for 24 hours. OSCC were cultured to a 100% confluency and a scratch was performed in the cell monolayer to create an artificial gap, simulating the wound. Immediately after performing the wound, the cells were treated with cell culture media with SCFA IC50 determined by our cytotoxicity assay. Results. Cell viability was reduced at higher concentrations for all three SCFAs. Butyrate and propionate did not show an IC50 at 24h. However, butyrate showed an IC 50 at 48h and 72h of 4.4mM and 9.1mM, respectively. Propionate at 48h and 72h showed an IC50 of 1.95 mM and 4.4 mM, respectively. Acetate showed an average IC50 of 261 mM at 24, 48 and 72 hours. In relation to migration, OSCC cell lines treated with butyrate (5nM) show lower motility at 24h when compared to the negative control. In contrast, faster motility was observed when OSCC was treated with acetate (5mM) compared to the negative control. Conclusions. Our results suggest that butyrate reduced oncogenic phenotypes in OSCC while acetate enhanced oncogenic phenotypes. Therefore, SCFAs seem promising alternative in reducing OSCC oncogenic phenotype but require further validation.​ Future work will focus on determining the effects on cell proliferation, migration, and epithelial-mesenchymal transition. Citation Format: Ariana S Garcia, Liah Marie Roman Calderon, Angel Amaral, Jeannette Salgado, Gabriel Borges, Esther Peterson, Josue Perez. The impact of the short-chain fatty acids on viability, motility and migration of oral squamous cell carcinoma cell line [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C122.

WITHDRAWN: Detection and impact of hypoxic regions in multicellular tumor spheroid cultures formed by head and neck squamous cell carcinoma cells lines

In solid tumors like head and neck cancer (HNC), chronic and acute hypoxia have serious adverse clinical consequences including poorer overall patient prognosis, enhanced metastasis, increased genomic instability, and resistance to radiation-, chemo-, or immuno-therapies. However, cells in the two-dimensional monolayer cultures typically used for cancer drug discovery experience 20%-21% O2 levels (normoxic) which are 4-fold higher than O2 levels in normal tissues and ≥10-fold higher than in the hypoxic regions of solid tumors. The oxygen electrodes, exogenous bio-reductive markers, and increased expression of endogenous hypoxia-regulated proteins like HIF-1α generally used to mark hypoxic regions in solid tumors are impractical in large sample numbers and longitudinal studies. We used a novel homogeneous live-cell permeant HypoxiTRAK™ (HPTK) molecular probe compatible with high content imaging detection, analysis, and throughput to identify and quantify hypoxia levels in live HNC multicellular tumor spheroid (MCTS) cultures over time. Accumulation of fluorescence HPTK metabolite in live normoxic HNC MCTS cultures correlated with hypoxia detection by both pimonidazole and HIF-1α staining. In HNC MCTSs, hypoxic cytotoxicity ratios for the hypoxia activated prodrugs (HAP) evofosfamide and tirapazamine were much smaller than have been reported for uniformly hypoxic 2D monolayers in gas chambers, and many viable cells remained after HAP exposure. Cells in solid tumors and MCTSs experience three distinct O2 microenvironments dictated by their distances from blood vessels or MCTS surfaces, respectively; oxic, hypoxic, or intermediate levels of hypoxia. These studies support the application of more physiologically relevant in vitro 3D models that recapitulate the heterogeneous microenvironments of solid tumors for preclinical cancer drug discovery.

Abstract B148: Novel low-atomic cluster Ag5 induced oxidative stress and antiproliferation in Esophageal Squamous Cell Carcinoma Cells

Abstract Background: Accumulation of reactive oxygen species (ROS) intensively activates cellular stress responses leading to cell death, thus ROS levels are strictly controlled by various antioxidants in normal cells. Esophageal cancer (ESCA), the sixth most common cause of cancer deaths, highly accumulates ROS under uncontrolled redox balances to activate oxidative-stress response pathways. Arjuna Therapeutics has developed a novel low-atomic cluster Ag5 as a ROS inducer, which strongly inhibits antioxidant pathways of glutathione and thioredoxin. In this study, we pharmacologically evaluate Ag5 on its therapeutic potential in preclinical ESCA models. Materials and Methods: Gene enrichment analyses were performed with 6,327 RNA-seq data of 14 cancer types in TCGA database. Cell panel studies of ATP-based cell viability was performed in vehicle control, Ag5 (3 uM), N-acetylcysteine (NAC, 5mM), and combination treatments in 31 esophageal squamous cell carcinoma (ESCC) cell lines and 5 non-ESCC cell lines. NAC) treatment was used as a rescue control of an antioxidant. We also conducted time-lapse imaging analysis with DCFDA (ROS indicator) and SYTOX (cell death marker). The morphology of mitochondria and ER were determined by electron microscope (EM). Results: Gene enrichment analyses revealed ROS-related genes were upregulated in ESCA compared to other cancer types. In the cell panel studies, Ag5 also exhibited potent antiproliferation in large numbers of ESCC cell lines, and NAC profoundly attenuated its antiproliferative activity. Time-lapse microscopy in ESCC cell line KYSE190 demonstrated that Ag5 increased DCFDA in 20 min and SYTOX in 60 min after the treatment, respectively, while combination treatment with NAC less detected these markers. Ag5-treated KYSE190 also exhibited necrosis-like morphology of swollen- and round-shape cells. In EM, damaged mitochondria and expanded endoplasmic reticulum were frequently observed in Ag5-treated KYSE190 cells. These data indicated that Ag5 induced ROS-mediated antiproliferation in ESCC cell lines. Conclusions: Ag5 exhibited ROS-mediated antiproliferative activities in large numbers of ESCC cell lines. Our preclinical results suggest the therapeutic potential of Ag5 as a novel cancer drug candidate for ESCC. Conflict of interest disclosure: AO is a part-time employee of Astellas Pharma Inc. from 2023 as a cross-appointment system. AO was an employee of Takeda Pharmaceutical Company, Ltd. AO reported paid consulting or advisory roles for Ono Pharmaceutical Company Ltd., Craif Inc., and GEXVal Inc. out of this study. AO receives research fundings from Astellas Pharma Inc., Astellas Pharma Global Development Inc., and Daiichi Sankyo Company, Ltd. out of this study. RB and MT are board members of Arjuna Therapeutics. Citation Format: Ryo Kamata, Toyohiro Yamauchi, Yuta Sakae, Ross Breckenridge, Martin Treder, Akihiro Ohashi. Novel low-atomic cluster Ag5 induced oxidative stress and antiproliferation in Esophageal Squamous Cell Carcinoma Cells [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr B148.

Proton Compared to X-Irradiation Induces Different Protein Profiles in Oral Cancer Cells and Their Derived Extracellular Vesicles

Extracellular vesicles (EVs) are membrane-bound particles released from cells, and their cargo can alter the function of recipient cells. EVs from X-irradiated cells have been shown to play a likely role in non-targeted effects. However, EVs derived from proton irradiated cells have not yet been studied. We aimed to investigate the proteome of EVs and their cell of origin after proton or X-irradiation. The EVs were derived from a human oral squamous cell carcinoma (OSCC) cell line exposed to 0, 4, or 8 Gy from either protons or X-rays. The EVs and irradiated OSCC cells underwent liquid chromatography–mass spectrometry for protein identification. Interestingly, we found different protein profiles both in the EVs and in the OSCC cells after proton irradiation compared to X-irradiation. In the EVs, we found that protons cause a downregulation of proteins involved in cell growth and DNA damage response compared to X-rays. In the OSCC cells, proton and X-irradiation induced dissimilar cell death pathways and distinct DNA damage repair systems. These results are of potential importance for understanding how non-targeted effects in normal tissue can be limited and for future implementation of proton therapy in the clinic.