Oral Cancer Cells Research Articles

Anti-Cancer Activities of Nano Amorphous Calcium Phosphates toward Premalignant and Oral Cancer Cells.

Despite advancements in treatment, the squamous cell carcinoma (OSCC) patient survival rate remains stagnant. Conventional therapies have limited effectiveness, necessitating novel agents. Our study aims to synthesize and characterize amorphous calcium phosphate nanoparticles (nACPs), assess their potential cytotoxic effects on premalignant and malignant OSCC cells, and investigate possible mechanisms of action. The morphological features of nACP were investigated by field emission scanning coupled with energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), and particle size distribution (PSD). Then, we examined the effect of nACPs on nanoparticle uptake, cell adhesion, viability, invasion ability, cell cycle, and gene expression. nACP uptake was dose-dependent, induced limited selectivity in cytotoxicity between healthy and malignant cells, and affected cellular adhesion and invasion. Early apoptosis was the predominant type of cell death. The nACP effect on viability was verified by alterations in the genes associated with apoptosis and proliferation. A high concentration of nACP was shown to arrest the cell cycle progression in the G0/G1 phase of both malignant and premalignant cells. This type of nACP justifies the development of a strategy for its potential use as an anti-cancer agent and/or anti-cancer active carrier for various drugs in oral cancer treatments.

Studies on In Vitro Antimicrobial, Anticancer, and Anti-oxidative Inflammatory Response of Methanolic Tuber Extracts Derived From Terminalia chebula.

Aim This study aims to investigate the antibacterial, antifungal, and phytochemical properties of methanolic tuber extracts from Terminalia chebula. Additionally, the study seeks to assess the in vitro anticancer effects of these extracts on an oral cancer cell line, as well as their antioxidant and anti-inflammatory activities. Materials and methods The research involves examining the antibacterial and antifungal properties of methanolic tuber extracts from Terminalia chebula. The phytochemical composition will be analyzed using standard techniques. The in vitro anticancer effects will be tested on an oral cancer cell line, while antioxidant and anti-inflammatory activities will be evaluated through appropriate assays. Results The study demonstrated that Terminalia chebula methanolic tuber extracts exhibit cytotoxic effects on the oral cancer cell line (KB-1), reducing cell viability as evidenced by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. A concentration of 30 µg/mL induced notable morphological changes observed under an inverted fluorescence microscope. Antioxidant assays showed a maximum absorption of 85.3% with 50 µL of the extract, while anti-inflammatory tests revealed a 76.0% absorption. Antimicrobial activity, assessed via agar-well diffusion, indicated significant antibacterial effects, especially against Streptococcus mutans and Candida albicans at higher concentrations. The findings suggest promising therapeutic potential for Terminalia chebula extracts. Conclusion Terminalia chebula tuber extracts may treat diseases caused by studied organisms. The study suggests that methanolic extracts from Terminalia chebula tubers have potential commercial value due to their anti-inflammatory, antioxidant, and cytotoxic properties. The extracts induced apoptosis in an oral cancer cell line at 30 µg/mL after 24 hours. Further research is needed to understand the active components and underlying molecular mechanisms.

تحضير ودراسة اللايكوبين الطبيعي والنانوي في تثبيط نمو الخلايا السرطانية خارج الجسم الحي In vitro

The effectiveness of both natural and nano-lycopene extracted from tomato waste powder in affecting the growth of cancer cells outside the body was studied. The study included the preparation of natural lycopene extract, using the triple mixture of hexane, acetone, and ethanol in proportions 2:1:1 and drying it, then preparing the nanocomposite using the high-energy mechanical grinding technique, and its dimensions were estimated using a Scanning Electron Microscope (SEM) and which was 78nm, and the effectiveness of the two preparations was tested in Inhibition of cancer cell lines of the human mouth and skin, during three periods of time 12, 24, 72 h and at concentrations of both natural and nano-lycopene 0.0,150, 300, 600, 1200, 2400 micrograms/ml, the results of the study showed There was a significant inhibitory effect p≤0.05. for both natural and nano-lycopene in the growth of cancer cells, and nano-lycopene was significantly superior to natural lycopene for skin and mouth models, and the inhibition effect of cancer cells increased for both natural and nano-lycopene with increasing concentration and period, and the highest percentage of inhibition for natural lycopene was 71% and 79.8% While the highest percentage of inhibition for nanoscale icon was 85.2% and 93.1% at a concentration of 2400 µg/ml for 72 h and for skin and oral cancer cell lines, respectively.

The Phytochemical Quantification and Pharmaceutical Potential Evaluation of Different Solvent Extracts of Sesbania aculeate

The present study aims for screening phytochemical content and exploring antibacterial, antioxidant and anticancer potential of different solvent extracts of different parts of Sesbania aculeata. The highest extract yield obtained for the ethanolic extract with the highest amount of the phytochemicals (alkaloids, saponins, tannins, phenols and flavonoids) tested. Ethanolic extracts (20.8-31.1 mm zone of inhibition) showed best antibacterial activity against the tested bacteria and also the highest antioxidant activity tested by the 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity and ferric reducing activity. The anticancer activity of ethanolic extracts tested against human oral cancer cell line SSC-29B and human kidney cancer cell line 786-O, where only seed coat extract which showed anticancer potential while other extracts showed negligible activity.

Enhanced applications in dentistry through autoclave-assisted sonochemical synthesis of Pb/Ag/Cu trimetallic nanocomposites

In recent years, researchers have increasingly focused on the development of multiphase trimetallic nanocomposites (TMNC) incorporating ternary metals or metal oxides, which hold significant potential as alternatives for combatting biofilms and bacterial infections. Enhanced oral health is ensured by the innovative techniques used to effectively prevent bacterial adherence and formation of biofilm on dental sutures. In this investigation, TMNC, which consists of Pb, Ag, and Cu, was synthesized using an autoclave-assisted sonochemical technique. Following synthesis, TMNC were characterized using FTIR, XRD, BET, XPS, TGA, and Raman spectroscopy to analyze their shape and microstructure. Subsequent evaluations, including MTT assay, antibacterial activity testing, and biofilm formation analysis, were conducted to assess the efficiency of the synthesized TMNC. Cytotoxicity and anti-human oral squamous cell carcinoma activities of TMNC were evaluated using the Human Oral Cancer cell line (KB) cell line through MTT assay, demonstrating a dose-dependent increase in anti-human oral squamous cell carcinoma activity against the KB cell line compared to the normal cell line, resulting in notably high cell viability. Furthermore, an ultrasonic probe was employed to incorporate TMNC onto dental suturing threads, with different concentrations of TMNC, ultrasonic power levels, and durations considered to determine optimal embedding conditions that result in the highest antibacterial activity. The inhibitory effects of TMNC, both in well diffusion assays and when incorporated into dental suturing threads, against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria on Mueller-Hinton agar (MHA) were assessed using various concentrations of TMNC. The results of the study indicated that the efficacy of TMNC in inhibiting bacterial growth on dental suturing threads remained impressive, even at low concentrations. Moreover, an evaluation of their potential to destabilize biofilms formed by S. aureus and E. coli, the two pathogens in humans, indicated that TMNC would be a promising anti-biofilm agent.

Bioinspired green synthesis of ZnO nanoparticles by marine-derived Streptomyces plicatus and its multifaceted biomedicinal properties

The present study explores the bioinspired green synthesis of zinc oxide nanoparticles (ZnONPs) using marine Streptomyces plicatus and its potent antibacterial, antibiofilm activity against dental caries forming Streptococcus mutans MTCC and S. mutans clinical isolate (CI), cytotoxicity against oral KB cancer cells, hemolysis against blood erythrocytes and artemia toxicity. The bioinspired ZnONPs showed a distinctive absorption peak at 375 nm in UV–Vis spectra, the FT-IR spectra divulged the active functional groups, and XRD confirmed the crystalline nature of the nanoparticles with an average grain size of 41.76 nm. SEM analysis evidenced hexagonal morphology, and EDX spectra affirmed the presence of zinc. The ZnONPs exerted higher antagonistic activity against S. mutans MTCC (Inhibitory zone: 19 mm; MIC: 75 μg/ml) than S. mutans CI (Inhibitory zone: 17 mm; MIC: 100 μg/ml). Results of biofilm inhibitory activity showed a concentration-dependent reduction with S. mutans MTCC (15 %–95 %) more sensitive than S. mutans CI (13 %–89 %). The 50 % biofilm inhibitory concentration (BIC50) of ZnONPs against S. mutans MTCC was considerably lower (71.76 μg/ml) than S. mutans CI (78.13 μg/ml). Confocal Laser Scanning Microscopic visuals clearly implied that ZnONPs effectively distorted the biofilm architecture of both S. mutans MTCC and S. mutans CI. This was further bolstered by a remarkable rise in protein leakage (19 %–85 %; 15 %–77 %) and a fall in exopolysaccharide production (34 mg–7 mg; 49 mg–12 mg). MTT cytotoxicity of ZnONPs recorded an IC50 value of 22.06 μg/ml against KB cells. Acridine orange/ethidium bromide staining showed an increasing incidence of apoptosis in KB cells. Brine shrimp cytotoxicity using Artemia salina larvae recorded an LC50 value of 78.41 μg/ml. Hemolysis assay substantiated the biocompatibility of the ZnONPs. This study underscores the multifaceted application of bioinspired ZnONPs in dentistry.

Nuclear translocation of β-catenin and migration of arecoline-induced oral cancer cells reduced by Taiwanin E via p-GSK3β downregulation

Nuclear translocation of β-catenin and migration of arecoline-induced oral cancer cells reduced by Taiwanin E via p-GSK3β downregulation

Antitumor activity of afatinib in EGFR T790M-negative human oral cancer therapeutically targets mTOR/Mcl-1 signaling axis.

This study investigates the role and effectiveness of the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) in oral cancer, focusing on the clinical relevance of EGFR and myeloid cell leukemia-1 (Mcl-1) in head and neck cancers (HNCs). It aims to explore the molecular mechanism of afatinib, a TKI, in treating human oral cancer. We conducted an in silico analysis using databases like The Cancer Genome Atlas, Gene Expression Omnibus, and Clinical Proteomic Tumor Analysis Consortium, along with immunohistochemistry staining, to study EGFR and Mcl-1 expression in HNCs. For investigating afatinib's anticancer properties, we performed various in vitro and in vivo analyses, including trypan blue exclusion assay, Western blotting, 4'-6-diamidino-2-phenylindole staining, flow cytometry, quantitative real-time PCR, Mitochondrial membrane potential assay, overexpression vector construction, transient transfection, and a tumor xenograft model. Higher expression levels of EGFR and Mcl-1 were observed in HNC patient tissues compared to normal tissues, with their co-expression significantly linked to poor prognosis. There was a strong correlation between EGFR and Mcl-1 expressions in oral cancer patients. Afatinib treatment induced apoptosis and suppressed Mcl-1 in oral cancer cell lines without the EGFR T790M mutation. The mechanism of afatinib-induced apoptosis involved the EGFR/mTOR/Mcl-1 axis, as shown by the effects of mTOR activator MHY1485 and inhibitor rapamycin. Afatinib also increased Bim expression, mitochondrial membrane permeabilization, and cytochrome c release. It significantly lowered tumor volume without affecting body, liver, and kidney weights. Afatinib, targeting the EGFR/mTOR/Mcl-1 axis, shows promise as a therapeutic strategy for oral cancer, especially in patients with high EGFR and Mcl-1 expressions.

Comparative study on the extraction methods, characterization, and bioactivity of crude fucoidan, a polysaccharide derived from Sargassum ilicifolium

Fucoidan, a sulfated polysaccharide known for its anticancer, immunomodulant, antioxidant and antimicrobial activity is abundant in brown seaweeds. Sargassum ilicifolium, a brown alga, was not extensively explored for fucoidan extraction using different methods and assessments of their impact on its structural and therapeutic characteristics. This study aimed to compare the structural features, biological activity, solubility, and emulsification characteristics of fucoidan extracted from Sargassum ilicifolium using conventional and ultrasonic bath extraction. The ultrasonic bath extraction method was 2.5 times higher than the conventional method to extract fucoidan. The structural integrity of fucoidan obtained by both methods was compared using FTIR, 1HNMR, XRD, FESEM, EDX, and DSC. The monosaccharide composition of fucoidan was determined by TLC. The IC50 values for antioxidant, anti-inflammatory and antitumor effects on oral cancer cells were found to be significantly lesser for crude fucoidan of S. ilicifolium obtained by ultrasonic bath method than for conventional extraction. Furthermore, fucoidan from the alga has emulsifying and water-holding characteristics which supports its potential use in the food processing industries.

Recent development in fibrin nanoparticles (F-NPs) and in vitro study targeting of oral cancer

Fibrin is limited by some factors that limit its clinical applicability, such as rapid degradation, poor water solubility, and low oral bioavailability. However, they can be applied clinically when they are included in the development of biocompatible fibrin nanoparticles (F-NPs). In this present study, F-NPs were prepared using co-precipitation techniques and In vitro studies using oral cancer cell lines also proved the anticancer activity of F-NPs. The study devised a technology for converting slaughterhouse waste into a value-added material such as anti-cancer F-NPs.

Effect of 5-Aminolevulinic Acid (5-ALA) in "ALADENT" Gel Formulation and Photodynamic Therapy (PDT) against Human Oral and Pancreatic Cancers.

Oral squamous-cell and pancreatic carcinomas are aggressive cancers with a poor outcome. Photodynamic therapy (PDT) consists of the use of photosensitizer-induced cell and tissue damage that is activated by exposure to visible light. PDT selectively acts on cancer cells, which have an accumulation of photosensitizer superior to that of the normal surrounding tissues. 5-aminolevulinic acid (5-ALA) induces the production of protoporphyrin IX (PpIX), an endogenous photosensitizer activated in PDT. This study aimed to test the effect of a new gel containing 5% v/v 5-ALA (ALAD-PDT) on human oral CAL-27 and pancreatic CAPAN-2 cancer cell lines. The cell lines were incubated in low concentrations of ALAD-PDT (0.05%, 0.10%, 0.20%, 0.40%, 0.75%, 1.0%) for 4 h or 8 h, and then irradiated for 7 min with 630 nm RED light. The cytotoxic effects of ALAD-PDT were measured using the MTS assay. Apoptosis, cell cycle, and ROS assays were performed using flow cytometry. PpIX accumulation was measured using a spectrofluorometer after 10 min and 24 and 48 h of treatment. The viability was extremely reduced at all concentrations, at 4 h for CAPAN-2 and at 8 h for CAL-27. ALAD-PDT induced marked apoptosis rates in both oral and pancreatic cancer cells. Elevated ROS production and appreciable levels of PpIX were detected in both cell lines. The use of ALA-PDT as a topical or intralesional therapy would permit the use of very low doses to achieve effective results and minimize side effects. ALAD-PDT has the potential to play a significant role in complex oral and pancreatic anticancer therapies.

Revitalizing oral cancer research: Crispr-Cas9 technology the promise of genetic editing.

This review presents an in-depth analysis of the immense potential of CRISPR-Cas9 technology in revolutionizing oral cancer research. It underscores the inherent limitations of conventional treatments while emphasizing the pressing need for groundbreaking approaches. The unparalleled capability of CRISPR-Cas9 to precisely target and modify specific genes involved in cancer progression heralds a new era in therapeutic intervention. Employing genome-wide CRISPR screens, vulnerabilities in oral cancer cells can be identified, thereby unravelling promising targets for therapeutic interventions. In the realm of oral cancer, the disruptive power of CRISPR-Cas9 manifests through its capacity to perturb genes that are intricately associated with drug resistance, consequently augmenting the efficacy of chemotherapy. To address the challenges that arise, this review diligently examines pertinent issues such as off-target effects, efficient delivery mechanisms, and the ethical considerations surrounding germline editing. Through precise gene editing, facilitated by CRISPR/Cas9, it becomes possible to overcome drug resistance by rectifying mutations, thereby enhancing the efficacy of personalized treatment strategies. This review delves into the prospects of CRISPR-Cas9, illuminating its potential applications in the domains of medicine, agriculture, and biotechnology. It is paramount to emphasize the necessity of ongoing research endeavors and the imperative to develop targeted therapies tailored specifically for oral cancer. By embracing this comprehensive overview, we can pave the way for ground-breaking treatments that instill renewed hope for enhanced outcomes in individuals afflicted by oral cancer.

Downstream Target Analysis for miR-365 among Oral Squamous Cell Carcinomas Reveals Differential Associations with Chemoresistance.

Expression of microRNAs, such as miR-365, is known to be dysregulated in many tumors, including oral cancers, although little is known about their role or functions. The objective of this project is to evaluate the downstream targets of miR-365 to determine any potential pathways or effects. Downstream targets for miR-365 (miRdatabase target scores > 90) were used for qPCR screening of oral cancer cell lines (SCC4, SCC9, SCC15, SCC25, CAL27). Each oral cancer cell line expressed miR-365 downstream targets molybdenum cofactor synthesis-2 (MOCS2), erythropoietin receptor (EPOR), IQ motif containing-K (IQCK), carboxypeptidase A3 (CPA3), solute carrier family 24 member-3 (SLC24A3), and coiled-coil domain containing 47 (CCDC47)-although the expression levels varied somewhat. However, differential results were observed with ubiquitin protein ligase E3 component n-recognin-3 (UBR3), nudix hydrolase-12 (NUDT12), zinc finger CCHC-type containing-14 (ZCCHC14), and homeobox and leucine zipper encoding (HOMEZ). These data suggest that many of the miR-365 targets are expressed in the oral cancers screened, with the differential expression of UBR3, ZCCHC14, HOMEZ, and NUDT12, which may be correlated with chemoresistance among two specific oral cancer cell lines (SCC25, SCC9). These results suggest this differential expression may signal potential targets for patient treatment with tumors exhibiting miR-365 and chemotherapeutic resistance.

Naringenin-induced Oral Cancer Cell Apoptosis Via ROS-mediated Bid and Bcl-xl Signaling Pathway.

Oral cancer is a malignant tumor with a high impact and poor prognosis. Naringenin, a flavonoid found in citrus fruits and its anti-inflammatory and antioxidant properties offer potential therapeutic benefits. However, limited studies have been conducted on the impact of naringenin on human tongue carcinoma CAL-27 cells. This study aims to elucidate the correlation between naringenin and tongue cancer, thereby identifying a potential therapeutic candidate for drug intervention against tongue cancer. The effect of naringenin on the apoptosis of CAL-27 cells and its mechanism were studied by cell counting kit-8, mitochondrial membrane potential assay with JC-1, Annexin V-- FITC apoptosis detection, cell cycle, and apoptosis analysis, Reactive Oxygen Species assay and Western blot. The results showed that naringenin significantly induced apoptosis in CAL-27 cells in a dose-dependent manner. Mechanistically, naringenin-induced apoptosis was mediated through the upregulation of Bid and downregulation of Bcl-xl, which led to increased generation of ROS. The findings suggested that naringenin may represent a promising candidate for the treatment of oral cancer by inducing apoptotic cell death via modulation of the Bid and Bcl-xl signaling pathways.

Antiretroviral Therapy and Cancers: Dolutegravir, Ritonavir and Zidovudine Have Toxic Effects on the Viability of Cal-27 Cancer Cell Line

Introduction: Effective HIV management through Highly Active Antiretroviral Therapy (HAART) is a crucial step in managing AIDSrelated Kaposi sarcoma, as emphasized by Kat [1]. Treatment for non-small cell lung cancer (NSCLC) in HIV patients significantly improves clinical outcomes Rengan et al. [2]. According to the American Cancer Society (2019), NSCLC encompasses squamous cell carcinoma, adenocarcinoma, and large cell carcinoma, constituting about 85% of lung cancer cases. Methods: This study addressed the question of whether both DTG and RTV have the ability to inhibit mitosis of CAL-27 cell line when compared to zidovudine. Results: A review of the dose response pattern versus efficacy against cancer cell viability of the selected ARDS revealed that these drugs have anti-mitotic properties. and may relieve patients of not only HIV infection, but also the additional burden of HIV-cancer. One-way Analysis of Variance (ANOVA) was used to compare the efficacies of the drugs, at 0.05 significance level (p ≤ 0.05). Conclusion: The antiretroviral compounds, (Zidovudine, Dolutegravir and Ritonavir) significantly suppress the viability of Cal-27 oral cancer cells, when compared to the control groups.

Coupling Kinesin Spindle Protein and Aurora B Inhibition with Apoptosis Induction Enhances Oral Cancer Cell Killing.

Many proteins regulating mitosis have emerged as targets for cancer therapy, including the kinesin spindle protein (KSP) and Aurora kinase B (AurB). KSP is crucial for proper spindle pole separation during mitosis, while AurB plays roles in chromosome segregation and cytokinesis. Agents targeting KSP and AurB selectively affect dividing cells and have shown significant activity in vitro. However, these drugs, despite advancing to clinical trials, often yield unsatisfactory outcomes as monotherapy, likely due to variable responses driven by cyclin B degradation and apoptosis signal accumulation networks. Accumulated data suggest that combining emerging antimitotics with various cytostatic drugs can enhance tumor-killing effects compared to monotherapy. Here, we investigated the impact of inhibiting anti-apoptotic signals with the BH3-mimetic Navitoclax in oral cancer cells treated with the selective KSP inhibitor, Ispinesib, or AurB inhibitor, Barasertib, aiming to potentiate cell death. The combination of BH3-mimetics with both KSP and AurB inhibitors synergistically induced substantial cell death, primarily through apoptosis. A mechanistic analysis underlying this synergistic activity, undertaken by live-cell imaging, is presented. Our data underscore the importance of combining BH3-mimetics with antimitotics in clinical trials to maximize their effectiveness.

Natural Prenylflavones from the Stem Bark of Artocarpus altilis: Promising Anticancer Agents for Oral Squamous Cell Carcinoma Targeting the Akt/mTOR/STAT-3 Signaling Pathway.

Artonin E (AA2) and artobiloxanthone (AA3) were extracted and purified from the acetone extract of the stem bark of Artocarpus altilis (Parkinson) Fosberg. Preliminary investigations of both candidates revealed promising cytotoxic effects in oral cancer cells. Moreover, these candidates modulated the expression of pivotal proteins linked to oral cancer progression, eliciting apoptosis through caspase-3 and caspase-9 activation. Additionally, our results showed that AA2 and AA3 suppressed several proteins linked with oral cancer, such as Bcl-2, COX-2, VEGF, and MMP-9, and modulated the cell signaling pathways, such as Akt/mTOR and STAT-3, offering valuable insights into the underlying mechanism of action of these compounds. These findings were robustly validated in silico using molecular docking and molecular dynamic simulations. To our knowledge, these findings have not been previously reported, and the continued exploration and development of these natural products may offer a potential avenue for the effective management of this malignancy.

7-amino carboxycoumarin 2inhibits lactate induced epithelial-to-mesenchymal transition via MPC1 in oral and breast cancer cells.

Lactate is an oncometabolite that play important role in tumor aggressiveness. Lactate from the tumor microenvironment (TME) is taken up by cancer cells as an energy resource via mitochondrial oxidative phosphorylation (or OXPHOS). In the present study, by using an online meta-analysis tool we demonstrated that in oral squamous cancer cells (OSCCs) glycolytic and OXPHOS governing genes are overexpressed, like in breast cancer. For experimental demonstration, we treated the OSCC cell line (SCC4) and breast cancer cells(MDA-MB-231) with sodium L-lactateand analyzed its effects on changes in EMT and migration. For the therapeutic intervention of lactate metabolism, we used AZD3965 (an MCT1 inhibitor), and 7ACC2 (an MPC inhibitor). Like breast cancer, oral cancer tissues showed increased transcripts of 12 genes that were previously shown to be associated with glycolysis and OXPHOS. We experimentally demonstrated that L-lactatetreatment induced mesenchymal markers and migration of cancer cells, which was significantly neutralized by MPC inhibitor that is, 7ACC2. Such an effect on EMT status was not observed with AZD3965. Furthermore, we showed that lactate treatment increases the MPC1 expression in both cancer cells, and this might be the reason why cancer cells in the high lactate environment are more sensitive to 7ACC2. Overall, our present findings demonstrate that extracellular lactate positively regulates the MPC1 protein expression in cancer cells, thereby putting forward the notion of using 7ACC2 as a potential therapeutic alternative to inhibit malignant oxidative cancers. Future preclinical studies are warranted to validate the present findings.

Isolation and phenotypic characterization of cancer stem cells from metastatic oral cancer cells.

To isolate cancer stem cells (CSC) from a metastatic oral squamous cell carcinoma (OSCC) cell line and investigate their invitro and invivo phenotypic characteristics. Subpopulations with individual staining intensities for CD44 and CD326 were isolated from the OSCC cell line LN-1A by FACS: CD44Low/CD326- (CSC-M1), CD44Low/CD326High (CSC-E), and CD44High/CD326- (CSC-M2). Proliferation, clonogenic potential, adhesion, migration, epithelial-mesenchymal transition markers, and sensitivity to cisplatin and TVB-3166 were analyzed invitro. Tumor formation and metastasis were assessed by subcutaneous and orthotopic inoculations into BALB/c mice. E-cadherin levels were higher in CSC-E cells while vimentin and Slug more produced by CSC-M2 cells. CSC-M1 and CSC-M2 subpopulations showed higher proliferation, produced more colonies, and have stronger adhesion to the extracellular matrix. All cell lines established tumors; however, CSC-E and CSC-M2 formed larger masses and produced more metastases. The CSC subpopulations here described show increased cancer capabilities invitro, tumorigenic and metastatic potential invivo, and may be exploited in the search for novel therapeutic targets for OSCC.

DNMT1-targeting remodeling global DNA hypomethylation for enhanced tumor suppression and circumvented toxicity in oral squamous cell carcinoma

BackgroundThe faithful maintenance of DNA methylation homeostasis indispensably requires DNA methyltransferase 1 (DNMT1) in cancer progression. We previously identified DNMT1 as a potential candidate target for oral squamous cell carcinoma (OSCC). However, how the DNMT1- associated global DNA methylation is exploited to regulate OSCC remains unclear.MethodsThe shRNA-specific DNMT1 knockdown was employed to target DNMT1 on oral cancer cells in vitro, as was the use of DNMT1 inhibitors. A xenografted OSCC mouse model was established to determine the effect on tumor suppression. High-throughput microarrays of DNA methylation, bulk and single-cell RNA sequencing analysis, multiplex immunohistochemistry, functional sphere formation and protein immunoblotting were utilized to explore the molecular mechanism involved. Analysis of human samples revealed associations between DNMT1 expression, global DNA methylation and collaborative molecular signaling with oral malignant transformation.ResultsWe investigated DNMT1 expression boosted steadily during oral malignant transformation in human samples, and its inhibition considerably minimized the tumorigenicity in vitro and in a xenografted OSCC model. DNMT1 overexpression was accompanied by the accumulation of cancer-specific DNA hypomethylation during oral carcinogenesis; conversely, DNMT1 knockdown caused atypically extensive genome-wide DNA hypomethylation in cancer cells and xenografted tumors. This novel DNMT1-remodeled DNA hypomethylation pattern hampered the dual activation of PI3K-AKT and CDK2-Rb and inactivated GSK3β collaboratively. When treating OSCC mice, targeting DNMT1 achieved greater anticancer efficacy than the PI3K inhibitor, and reduced the toxicity of blood glucose changes caused by the PI3K inhibitor or combination of PI3K and CDK inhibitors as well as adverse insulin feedback.ConclusionsTargeting DNMT1 remodels a novel global DNA hypomethylation pattern to facilitate anticancer efficacy and minimize potential toxic effects via balanced signaling synergia. Our study suggests DNMT1 is a crucial gatekeeper regarding OSCC destiny and treatment outcome.