Growth Of Oral Cancer Cells Research Articles

Upregulation of ENAH by a PI3K/AKT/β-catenin cascade promotes oral cancer cell migration and growth via an ITGB5/Src axis

BackgroundOral cancer accounts for 2% of cancer-related deaths globally, with over 90% of cases being oral cavity squamous cell carcinomas (OSCCs). Approximately 50% of patients with OSCC succumb to the disease within 5 years, primarily due to the advanced stage at which it is typically diagnosed. This underscores an urgent need to identify proteins related to OSCC progression to develop effective diagnostic and therapeutic strategies.MethodsTo identify OSCC progression-related proteins, we conducted integrated proteome and transcriptome analyses on cancer tissues from patients and patient-derived xenograft (PDX) model mice. We investigated the role of protein-enabled homolog (ENAH), identified as an OSCC progression-associated protein, through proliferation, transwell migration, and invasion assays in OSCC cells. The mechanisms underlying ENAH-mediated functions were elucidated using gene knockdown and ectopic expression techniques in OSCC cells.ResultsENAH was identified as a candidate associated with OSCC progression based on integrated analyses, which showed increased ENAH levels in primary OSCC tissues compared with adjacent noncancerous counterparts, and sustained overexpression in the cancer tissues of PDX models. We confirmed that level of ENAH is increased in OSCC tissues and that its elevated expression correlates with poorer survival rates in patients with OSCC. Furthermore, the upregulation of ENAH in OSCC cells results from the activation of the GSK3β/β-catenin axis by the EGFR/PI3K/AKT cascade. ENAH expression enhances cell proliferation and mobility by upregulating integrin β5 in oral cancer cells.ConclusionsThe upregulation of ENAH through a PI3K/AKT/β-catenin signaling cascade enhances oral cancer cell migration and growth via the ITGB5/Src axis. These findings offer a new interpretation of the ENAH function in the OSCC progression and provide crucial information for developing new OSCC treatment strategies.

Natural compounds targeting miRNAs: a novel approach in oral cancer therapy.

Oral cancer (OC) is a significant global health issue, with high rates of both mortality and morbidity. Conventional treatments, including surgery, radiation, and chemotherapy, are commonly used, but they often come with serious side effects and may not fully eliminate cancer cells, resulting in recurrence and resistance to treatment. In recent years, natural products derived from plants and other biological sources have gained attention for their potential anticancer properties. These compounds offer advantages such as lower toxicity compared to traditional chemotherapy. Notable natural compounds like quercetin, berberine, curcumin, andrographolide, nimbolide, ovatodiolide, and cucurbitacin B have demonstrated effectiveness in inhibiting OC cell growth by targeting various signaling pathways involved in cancer progression. Recent breakthroughs in molecular biology have highlighted the crucial role of microRNAs (miRNAs) in the development of OC. Targeting dysregulated miRNAs with natural products offers a promising strategy for treating the disease. Natural compounds exert anticancer effects by influencing both altered cellular signaling pathways and miRNA expression profiles. This study aims to explore the role of miRNAs as potential molecular targets in OC and to investigate how natural products may regulate these miRNAs. Additionally, this review will shed light on the therapeutic potential of phytochemicals in modulating miRNA expression and their significance in OC treatment.

Anti-Oxidant and Anti-Cancerous Properties of Pyrus pashia (Buch. -Ham.Ex D.Don) Against KB-3-1 Cancer Cell Lines In Vitro

Background: Oral cancer is the fastest-growing cancer in men. Many medicinal approaches are tried step-wise for cancers. Homeopathy and Ayurveda are contributing much to cure cancers without side effects. Plants having antioxidant properties are now being utilized with different solvents to extract different chemical compounds to cure cancer. Objective: The current study aimed to examine the anti-cancer and antioxidant properties of acetone extract of Pyrus pashia (PP-AE) fruit against KB-3-1 cancer cell lines. Materials and Methods: The extract's total phenolic content was determined using a folin-ciocalteu reagent. The DPPH, ABTS, and H2O2 assay were used to measure the free radical scavenging activity of the PP-AE. The MTT assay was used to evaluate the cytotoxic efficacy of the PP-AE against KB-3-1 cancer cell lines at various concentrations. Results: Based on the observations, the total phenolic content was present in the PP-AE of fruit and all free radical scavenging assays have shown remarkable IC50 values. Conclusion: According to the current study, acetone extract of Pyrus pashia fruit significantly possesses antioxidant and anti-cancer properties against oral (KB-3-1) cancer cell lines. This effect may be used in the future to analyze particular chemical compounds in extract, capable of minimizing the growth of oral cancer cells.

Enhanced Therapeutic Efficacy of Gold Nanoparticle-Enhanced Laser Therapy for Oral Cancer: A Promising Photothermal Approach.

Introduction: Laser therapy employs a concentrated and slender light beam to eliminate or eradicate cancerous cells and pre-cancerous abnormalities. The specific wavelength of 808 nm light is preferentially absorbed by tumor cells compared to healthy cells. This study aimed to assess the combined therapeutic impact of laser and gold, given that gold exhibits photothermal properties when exposed to laser radiation. Methods: In this in vitro study, two cell lines, namely healthy HuGu cells (human gingival fibroblast cells) and head and neck cancer cells (HN-5), were obtained from the Pasteur Institute. The effect of the laser diode with a density of 3 J/cm2 and wavelength of 808 nm on the proliferation and the survival rate of oral squamous cell carcinoma (HN-5) and human gingival fibroblast (HUGU) was assessed in 60seconds. MTT assay, DAPI test, and trypan blue staining were used to determine the growth and proliferation of HN-5 and HUGU cell lines. Results: Findings showed that the laser diode along with gold decreased the rate of proliferation and survival cells in HN-5 compared to healthy cells. The changes in the cell population treated with gold and laser diode 808 were insignificant. Conclusion: Findings reveal that using a low-power laser can effectively inhibit the growth of oral cancer cells. It seems that photothermal therapy is a novel approach to oral cancer therapy.

Let-7 reduces the proliferation and migration of oral cancer cells via PI3K/AKT signaling pathway.

The involvement of let-7 in the occurrence and progression of various cancers has been well-documented. However, the precise molecular mechanisms underlying its impact on oral cancer development remain unclear. In this study, we aimed to elucidate the role of let-7 in oral cancer progression and investigate its underlying molecular mechanisms. The expression of let-7 and high mobility group A2 (HMGA2) mRNA was assessed using the quantitative reverse transcription polymerase chain reaction. Western blot analysis was employed to detect the expression of key proteins in the PI3K/AKT signaling pathway as well as HMGA2 protein levels. The targeting relationship between let-7 and HMGA2 was predicted through bioinformatics methods and confirmed via luciferase reporter gene assay. The effects of let-7 and HMGA2 on the functionality of oral cancer cells were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, colony formation assay, Transwell assay, wound healing assay, and Annexin V/PI apoptosis assay. Additionally, the impact of let-7 on the growth of oral cancer cells in vivo was investigated by inducing subcutaneous tumor formation in nude mice. Let-7 effectively suppresses the proliferation, migration, and invasion of oral cancer cells by inhibiting the activation of the PI3K/AKT signaling pathway. HMGA2, a downstream target gene of let-7, exhibits high expression in oral cancer. However, overexpression of HMGA2 diminishes the inhibitory effects induced by let-7 overexpression on the proliferation, migration, and invasion of oral cancer cells. The occurrence and progression of oral cancer cells are inhibited by Let-7 through the downregulation of HMGA2, potentially mediated by the inhibition of PI3K/AKT signaling pathway activation.

The Role of Medicinal Plants in the Treatment of Oral Cancers in vitro: A Systematic Review

Introduction: The use of medicinal plant compounds for cancer treatment has been considered since ancient times. This systematic study aimed to conduct a review on the effects of medicinal plant extracts on oral cancer cell lines in vitro. Methods: In this systematic study, articles were searched in databases, including PubMed, Google Scholar, ScienceDirect, Web of Science, and Scopus, using keywords as "herbal drugs", "medicinal plants", "extract", "essence", "oral cancer", "in vitro", and "clinical trials". Results: After searching the articles according to inclusion and exclusion criteria, removing duplicates, and reviewing full-text articles, the researchers entered the data of all the collected articles into Endnote X9. Initially, 14,650 studies were identified, but after applying the inclusion/ exclusion criteria, 21 studies were selected. Conclusion: According to the inclusion and exclusion criteria, 21 studies have been selected. The study's findings have revealed that medicinal plants have the potential to inhibit the growth of oral cancer cells, making them a promising candidate for further research on cancer treatment.

Chaga mushroom extract suppresses oral cancer cell growth via inhibition of energy metabolism

Oral cancer stands as a prevalent maligancy worldwide; however, its therapeutic potential is limited by undesired effects and complications. As a medicinal edible fungus, Chaga mushroom (Inonotus obliquus) exhibits anticancer effects across diverse cancers. Yet, the precise mechanisms underlying its efficacy remain unclear. We explored the detailed mechanisms underlying the anticancer action of Chaga mushroom extract in oral cancer cells (HSC-4). Following treatment with Chaga mushroom extracts, we analyzed cell viability, proliferation capacity, glycolysis, mitochondrial respiration, and apoptosis. Our findings revealed that the extract reduced cell viability and proliferation of HSC-4 cells while arresting their cell cycle via suppression of STAT3 activity. Regarding energy metabolism, Chaga mushroom extract inhibited glycolysis and mitochondrial membrane potential in HSC-4 cells, thereby triggering autophagy-mediated apoptotic cell death through activation of the p38 MAPK and NF-κB signaling pathways. Our results indicate that Chaga mushroom extract impedes oral cancer cell progression, by inhibiting cell cycle and proliferation, suppressing cancer cell energy metabolism, and promoting autophagy-mediated apoptotic cell death. These findings suggest that this extract is a promising supplementary medicine for the treatment of patients with oral cancer.

Hesperidin Inhibits Oral Cancer Cell Growth via Apoptosis and Inflammatory Signaling-Mediated Mechanisms: Evidence From In Vitro and In Silico Analyses.

Background Oral carcinoma presents a significant health challenge, prompting the need for innovative therapeutic approaches. Elevation of inflammatory mediators, including tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), has promoted cellular proliferation, inhibited apoptosis, and fostered oral cancer progression through complex signaling pathways. Hesperidin, a flavanone glycoside found in citrus fruits, is of keen interest in this study as it has been proven to have multiple health benefits through in vivo and in vitro studies. However, the mechanism behind the anticancer activity of hesperidin in oral carcinoma remains obscure. Aim The study aimed to explore the anticancer potential of hesperidin on human oral cancer cells (KB cells) by modulating pro-inflammatory and apoptotic signaling mechanisms. Methods Cancer cell growth inhibitory activity was assessed using the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay. Gene expression analysis was performed using real-time RT-PCR analysis. In addition, in silico docking analysis was conducted to confirm the binding affinity of hesperidin with pro-inflammatory and apoptosis signaling molecules. The data were analyzed using one-way ANOVA and the "t" test. Results Utilizing the MTT assay, a dose-dependent cytotoxic effect of hesperidin was unveiled, with a remarkable IC50 value indicative of its potent inhibition of cell proliferation. Complementing these findings (p<0.05), qRT-PCR analysis demonstrated hesperidin's regulatory influence on key molecular targets within the KB cell line. Hesperidin treatment resulted in a noteworthy reduction in TNF-α, interleukin-1 beta (IL-1-β), IL-6, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and B-cell lymphoma 2 (Bcl-2) mRNA expression levels (p<0.05), highlighting its inhibitory role in cell proliferation, migration, and inflammation processes. Simultaneously, hesperidin promoted the expression of BAX mRNA (p<0.05), indicating an enhancement in cell death. Molecular docking simulations further revealed robust binding affinities between hesperidin and target proteins, suggesting its potential to disrupt cellular functions and inflammatory signaling pathways in oral cancer cells. Conclusion The cytotoxic effects on the KB cell line and its anti-inflammatory properties position hesperidin as a compelling candidate for further exploration in the quest for effective oral carcinoma treatments. These findings shed light on the intricate molecular mechanisms underlying hesperidin's promise as a therapeutic agent against oral carcinoma.

Unveiling the anti-cancer mechanisms of calotropin: Insights into cell growth inhibition, cell cycle arrest, and metabolic regulation in human oral squamous carcinoma cells (HSC-3)

BackgroundCalotropin, a cardiac glycoside obtained from the plant Calotropis gigantea, has demonstrated promising potential as an anti-tumorigenesis compound. ObjectiveThe main objective of this study was to investigate the potential anti-cancer properties of calotropin against HSC-3 oral squamous cancer cells and to elucidate the underlying mechanisms involved in its action. Material and methodCalotropin were treated in HSC-3 to evaluate cell viability by MTT assay. Flow cytometry analysis divulged that calotropin G0/G1 phase cell cycle arrest and apoptosis in HSC-3 cells. Calotropin displayed inhibitory properties against aerobic glycolysis, a metabolic alteration using glucose uptaken, lactose production and LDHA activity assays. Furthermore, migration and invasion assays help that calotropin has ability to reduce the migratory and invasive of HSC-3 cells, using transwell and Matrigel assay. Validation of mRNA expression through RT-PCR. Molecular docking was implemented to validate the binding association of calotropin with apoptosis and metastatic regulating targets. ResultThe results exemplify that increasing doses of calotropin effectively hold back the HSC-3 cell progression. Migration and invasion assays help that calotropin has ability to reduce the migratory and invasive of HSC-3 cells, indicating its potential to inhibit cancer metastasis. These results imply that calotropin may influence genes linked to metastasis and apoptosis in order to achieve its beneficial effects on cancer. Docking results provided further support, showing a high binding energy between calotropin and metastasis-mediated pathways. ConclusionOverall, our findings shed an experimental evidence on how calotropin inhibits the HSC-3 oral squamous cancer cell growth, highlighting the drug's potential as a treatment for oral cancer. Further, investigation on in-vivo experiment is warranted to explore its potential mechanism of action and to develop a novel drug towards clinical trial.

Overexpression of long non-coding RNA GASL1 induces apoptosis and G0/G1 cell cycle arrest in human oral cancer cells

Oral cancer is one of the commonly reported malignancies of the human oral cavity and pharynx. It accounts for a significant level of cancer-based mortality across the globe. Long non-coding RNAs (lncRNAs) are emerging as important study targets in cancer therapy. The present study aimed to characterize the role of lncRNA GASL1 in regulating the growth, migration, and invasion of human oral cancer cells. The qRT-PCR showed significant (P&lt;0.05) upregulation of GASL1 in oral cancer cells. Overexpression of GASL1 led to the loss of viability of HN6 oral cancer cells by inducing apoptosis which was associated with upregulation of Bax and downregulation of Bcl-2. The apoptotic cell percentage increased from 2. 81% in control to 25.89% upon GASL1 overexpression. Cell cycle analysis showed that overexpression of GASL1 increased the G1 cells from 35.19% in control to 84.52% upon GASL1 overexpression indicative of G0/G1 cell cycle arrest. Cell cycle arrest was also accompanied by inhibition of cyclin D1 and CDK4 protein expression. Wound healing and transwell assays showed that overexpression of GASL1 significantly (P&lt;0.05) inhibited the migration and invasion of HN6 oral cancer cells. The invasion of the HN6 oral cancer cells was found to be decreased by more than 70%. Finally, the results of in vivo study revealed that GASL1 overexpression inhibits the xenografted tumor growth in vivo. Thus, the results are thus suggestive of the tumor-suppressive molecular role of GASL1 in oral cancer cells.

Pomegranate extract mechanism in inhibiting the development of oral cancer: A review

Background: Oral cancer is one of the most aggressive and invasive cancers with high metastatic potential. Oral cancer is cancer with the 11th highest number of cases in the world. Oral cancer is treated with chemotherapy and radiotherapy. However, this therapy causes side effects in the form of damage to normal cells in the surrounding tissue. Pomegranate extract contains polyphenols which may be great for inhibiting the development of oral cancer. Purpose: This article presents a systematic and comprehensive review of the potential of pomegranate extract as a natural product to inhibit the development of oral cancer. Review: Pomegranate extract was obtained by ethanol extraction using maceration method. The main content of pomegranate is polyphenolic compounds such as punicalagin, tannins, flavonoids, and ellagic acid. This compound reduces ATP formation, shortens the subG1 phase, and increases apoptosis. At the microcellular level, pomegranate extract can inhibit the activity of MMP-2 or MMP-9 to produce anti-proliferative, anti-angiogenesis and pro-apoptotic processes of cancer cells at concentrations of 25 and 50 μg/ml. Anti-proliferative and pro-apoptotic effects are produced through mitochondrial damage mechanisms. Exposure after 72 hours can reduce oral cell viability greater than exposure after 24 hours. Conclusion: Pomegranate extract is likely has four mechanisms to oral cancer: inhibiting the invasion, migration and growth of oral cancer cells, increasing oral cancer cell apoptosis and regulating antioxidant genes. So that this material can be used as a candidate for oral cancer therapy.

Rhein Induces Oral Cancer Cell Apoptosis and ROS via Suppresse AKT/mTOR Signaling Pathway In Vitro and In Vivo.

Oral cancer remains the leading cause of death worldwide. Rhein is a natural compound extracted from the traditional Chinese herbal medicine rhubarb, which has demonstrated therapeutic effects in various cancers. However, the specific effects of rhein on oral cancer are still unclear. This study aimed to investigate the potential anticancer activity and underlying mechanisms of rhein in oral cancer cells. The antigrowth effect of rhein in oral cancer cells was estimated by cell proliferation, soft agar colony formation, migration, and invasion assay. The cell cycle and apoptosis were detected by flow cytometry. The underlying mechanism of rhein in oral cancer cells was explored by immunoblotting. The in vivo anticancer effect was evaluated by oral cancer xenografts. Rhein significantly inhibited oral cancer cell growth by inducing apoptosis and S-phase cell cycle arrest. Rhein inhibited oral cancer cell migration and invasion through the regulation of epithelial-mesenchymal transition-related proteins. Rhein induced reactive oxygen species (ROS) accumulation in oral cancer cells to inhibit the AKT/mTOR signaling pathway. Rhein exerted anticancer activity in vitro and in vivo by inducing oral cancer cell apoptosis and ROS via the AKT/mTOR signaling pathway in oral cancer. Rhein is a potential therapeutic drug for oral cancer treatment.

Synergistic Effect of Anethole and Platinum Drug Cisplatin against Oral Cancer Cell Growth and Migration by Inhibiting MAPKase, Beta-Catenin, and NF-κB Pathways.

Cisplatin is a common drug used to treat patients with oral squamous cell carcinoma. However, cisplatin-induced chemoresistance poses a major challenge to its clinical application. Our recent study has shown that anethole possesses an anti-oral cancer effect. In this study, we examined the combined effect of anethole and cisplatin on oral cancer therapy. Gingival cancer cells Ca9-22 were cultured in the presence of various concentrations of cisplatin with or without anethole. The cell viability/proliferation and cytotoxicity were evaluated, respectively, by MTT, Hoechst staining, and LDH assay, while colony formation was measured by crystal violet. Oral cancer cell migration was evaluated by the scratch method. Apoptosis, caspase activity, oxidative stress, MitoSOX, and mitochondrial membrane potential (ΔΨm) levels were evaluated by flow cytometry, and the inhibition of signaling pathways was investigated by Western blot. Our results show that anethole (3 µM) potentiates cisplatin-induced inhibition of cell proliferation and decreases the ΔΨm on Ca9-22 cells. Furthermore, drug combination was found to inhibit cell migration and enhanced cisplatin cytotoxicity. The combination of anethole and cisplatin potentiates cisplatin-induced oral cancer cell apoptosis through the activation of caspase, while we also found anethole and cisplatin to enhance the cisplatin-induced generation of reactive oxygen species (ROS) and mitochondrial stress. In addition, major cancer signaling pathways were inhibited by the combination of anethole and cisplatin such as MAPKase, beta-catenin, and NF-κB pathways. This study reports that the combination of anethole and cisplatin might provide a beneficial effect in enhancing the cisplatin cancer cell-killing effect, thus lowering the associated side effects.

Abstract 6302: Identification of OASEP1 as a biomarker and therapeutic target for oral cancer

Abstract This study aims to identify new biomarkers and therapeutic targets for oral cancer. Our strategies are as follows: i) Identification of overexpressed genes in oral cancers by gene expression array analysis, ii) Validation of clinicopathologic significance of their protein expression by tissue microarray, iii) Examination of their growth effect on cancer cell by siRNAs. We identified a secreted protein, OASEP1 (oral cancer-associated serum protein 1) as a candidate. Immunohistochemical staining showed that OASEP1 protein expression was observed in 120 (75.4%) of 159 oral cancers that had undergone curative surgery. High level of OASEP1 expression was associated with poor prognosis for oral cancer patients (P = 0.0054, by log-rank test). Multivariate analysis revealed that strong OASEP1 expression was an independent prognostic factor. Suppression of OASEP1 expression by siRNA significantly inhibited the growth of oral cancer cell lines through apoptosis as detected by apoptosis assays and time lapse imaging. Transient OASEP1 overexpression significantly enhanced the growth of oral cancer cells. In addition, knock down of OASEP1 receptor by siRNAs also significantly inhibited the growth of oral cancer cells. Addition of OASEP1 protein significantly increased the growth of oral cancer cells in a dose dependent manner, suggesting that the interaction between OASEP1 and its receptor regulated the growth of oral cancer cells. Microarray analysis coupled with siRNAs for OASEP1 demonstrated various OASEP1-related oncogenic pathways in oral cancer cells. Our data suggest that OASEP1 is a possible prognostic biomarker and therapeutic target for oral cancer. Citation Format: Atsushi Takano, Yoshihiro Yoshitake, Masahiro Shinohara, Yataro Daigo. Identification of OASEP1 as a biomarker and therapeutic target for 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 6302.

Dual Axl/MerTK inhibitor INCB081776 creates a proinflammatory tumor immune microenvironment and enhances anti-PDL1 efficacy in head and neck cancer.

The tyrosine kinase receptors Axl and MerTK are highly overexpressed in head and neck cancer (HNC) cells, where they are critical drivers of survival, proliferation, metastasis, and therapeutic resistance. We investigated the role of Axl and MerTK in creating an immunologically "cold" tumor immune microenvironment (TIME) by targeting both receptors simultaneously with a small molecule inhibitor of Axl and MerTK (INCB081776). Effects of INCB081776 and/or anti-PDL1 on mouse oral cancer (MOC) cell growth and on the TIME were evaluated. Targeting Axl and MerTK can reduce M2 and induce M1 macrophage polarization. In vivo, INCB081776 treatment alone or with anti-PDL1 appears to slow MOC tumor growth, increase proinflammatory immune infiltration, and decrease anti-inflammatory immune infiltration. This data indicates that simultaneous targeting of Axl and MerTK with INCB081776, either alone or in combination with anti-PDL1, slows tumor growth and creates a proinflammatory TIME in mouse models of HNC.

Silibinin induces oral cancer cell apoptosis and reactive oxygen species generation by activating the JNK/c-Jun pathway.

Background: Oral cancer is one of the most prevalent malignant tumors worldwide. Silibinin has been reported to exert therapeutic effects in various cancer models. However, its mechanism of action in oral cancer remains unclear. We aimed to examine the molecular processes underlying the effects of silibinin in oral cancer in vitro and in vivo as well as its potential anticancer effects. Next, we investigated the molecular processes underlying both in vitro and in vivo outcomes of silibinin treatment on oral cancer. Methods: To investigate the effects of silibinin on the growth of oral cancer cells, cell proliferation and anchorage-independent colony formation tests were conducted on YD10B and Ca9-22 oral cancer cells. The effects of silibinin on the migration and invasion of oral cancer cells were evaluated using transwell assays. Flow cytometry was used to examine apoptosis, cell cycle distribution, and accumulation of reactive oxygen species (ROS). The molecular mechanism underlying the anticancer effects of silibinin was explored using immunoblotting. The in vivo effects of silibinin were evaluated using a Ca9-22 xenograft mouse model. Results: Silibinin effectively suppressed YD10B and Ca9-22 cell proliferation and colony formation in a dose-dependent manner. Moreover, it induced cell cycle arrest in the G0/G1 phase, apoptosis, and ROS generation in these cells. Furthermore, silibinin inhibited the migration and invasion abilities of YD10B and Ca9-22 cells by regulating the expression of proteins involved in the epithelial-mesenchymal transition. Western blotting revealed that silibinin downregulated SOD1 and SOD2 and triggered the JNK/c-Jun pathway in oral cancer cells. Silibinin significantly inhibited xenograft tumor growth in nude mice, with no obvious toxicity. Conclusions: Silibinin considerably reduced the development of oral cancer cells by inducing apoptosis, G0/G1 arrest, ROS generation, and activation of the JNK/c-Jun pathway. Importantly, silibinin effectively suppressed xenograft tumor growth in nude mice. Our findings indicate that silibinin may be a promising option for the prevention or treatment of oral cancer.

Resveratrol Inhibits Proliferation and Induces Autophagy by Blocking SREBP1 Expression in Oral Cancer Cells

Resveratrol is a polyphenolic antioxidant found in grapes, red wine, and peanuts and has been reported to have anti-neoplastic effects on various cancer types. However, the exact mechanism of its anti-cancer effects in oral cancer is not fully understood and remains controversial. Resveratrol exhibits strong hypolipidemic effects; therefore, we examined its effect on lipid metabolism in oral cancer. Resveratrol significantly reduced cell viability and induced autophagic cell death in oral cancer cells but not in normal cells. This selective effect was accompanied by significantly reduced lipogenesis, which is caused by downregulation of the transcription factor sterol regulatory element-binding protein 1 (SREBP1) gene, followed by downregulation of the epidermal fatty acid-binding protein (E-FABP). It was strongly suggested that resveratrol-induced autophagy resulted from the inhibition of SREBP1-mediated cell survival signaling. Luciferase reporter assay further indicated that resveratrol has a potent and specific inhibitory effect on SREBP1-dependent transactivation. Importantly, resveratrol markedly suppressed the growth of oral cancer cells in an animal xenograft model, without exhibiting apparent cytotoxicity. In conclusion, resveratrol induces autophagy in oral cancer cells by suppressing lipid metabolism through the regulation of SREBP1 expression, which highlights a novel mechanism of the anti-cancer effect of resveratrol.

Erianin inhibits oral cancer cell growth, migration, and invasion via the Nrf2/HO-1/ GPX4 pathway

Objective: To evaluate the effect of erianin on the viability, migration, and invasion of KB cells and elucidate its underlying mechanisms. Methods: Cell Counting Kit-8, colony formation, wound healing, and Transwell assays were used to determine the proliferation, migration, and invasion of oral cancer KB cells. Furthermore, malondialdehyde (MDA) and glutathione (GSH) levels were determined. Fluorescent probes were used to detect changes in intracellular reactive oxygen species and iron ions. Additionally, the expressions of ferroptosis-related proteins, NF-E2-related factor 2 (Nrf2), ferritin heavy chain 1 (FTH1), heme oxygenase 1 (HO-1), and glutathione peroxidase 4 (GPX4) were analyzed by Western blotting assays. Results: Erianin induced ferroptosis and inhibited the proliferation, migration, and invasion of KB cells. Moreover, erianin decreased GSH level, increased MDA level, elevated intracellular ROS and Fe2+ contents, and downregulated the expression of the ferroptosis-related proteins Nrf2, HO-1, GPX4, and FTH1 in KB cells. These effects of erianin were effectively reversed by a ferroptosis inhibitor, ferrostatin-1. Conclusions: Erianin inhibits the proliferation, migration, and invasion of oral cancer cells and induces ferroptosis via the Nrf2/HO-1/GPX4 signaling pathway. Therefore, erianin may be a potential candidate for the treatment of oral cancer.

Rapamycin inhibits oral cancer cell growth by promoting oxidative stress and suppressing ERK1/2, NF-κB and beta-catenin pathways.

Treatment of oral cancer is based exclusively on surgery combined with or without chemotherapy. However, it has several side effects. Targeting a new, more effective therapy has become an urgent matter. The purpose of this study was to evaluate the anti-tumor activity of rapamycin in oral cancer and its mechanism of action. Human gingival carcinoma cells were stimulated with different concentrations of rapamycin to assess proliferation, colony formation, cell migration, as well as apoptosis, and autophagy. The expression of proteins involved in the cell cycle (cyclin D1, p15, p21, p27) and autophagy, as well as that of oncogenes and tumor suppressor genes, were determined by quantitative PCR. The signaling pathways were evaluated by Western blotting. Our results show that rapamycin has a selective effect at a low dose on cancer cell growth/survival. This was confirmed by low colony formation and the inhibition of cell migration, while increasing cell apoptosis by activating caspase-9 and -3. Rapamycin promoted cell autophagy and increased mitochondrial oxidative stress by being involved in DNA damage in the exposed cells. Finally, rapamycin exhibits potent anti-oral cancer properties through inhibition of several cancer-promoting pathways (MAPK, NF-κB, and Wnt/beta-catenin). These results indicate that rapamycin could be a potential agent for the treatment of oral cancer and for a prevention strategy.

MAP3K11 facilitates autophagy activity and is correlated with malignancy of oral squamous cell carcinoma.

Autophagy-related 4B (ATG4B) is a protease required for core machinery of autophagy. Phosphorylation of ATG4B promotes autophagy and is correlated with poor outcome of cancer. However, little is known about the upstream kinases for ATG4B phosphorylation and their association with clinical outcomes of cancer patients.Through siRNA library screening, MAP3K11 was identified as a potential kinase that phosphorylates ATG4B and increases its proteolytic activity. Ablation of MAP3K11 attenuated pS383/392-ATG4B protein levels and autophagic flux in oral cancer cells. Moreover, loss of MAP3K11 inhibited oral cancer cell growth, migration/invasion, and synergized starvation-reduced cell viability. MAP3K11knock-out cancer cells also showed growth inhibition in vivo. Furthermore, the protein level of MAP3K11 was higher in tumor tissues than that in adjacent normal tissues in patients with oral squamous cell carcinoma (OSCC), comprising 179 buccal mucosa squamous cell carcinoma (BMSCC) and 249 tongue squamous cell carcinoma (TSCC). MAP3K11 protein levels were positively correlated with ATG4B and pS383/392-ATG4B levels in patients with OSCC, particularly in TSCC. In addition, high coexpression of MAP3K11 and ATG4B was associated with poor disease-specific survival in BMSCC and TSCC, while high coexpression of MAP3K11 and pS383/392-ATG4B was associated with unfavorable disease-free survival in BMSCC and TSCC. Taken together, our results indicated that MAP3K11 stimulated activity of ATG4B and autophagy, which may confer to malignancy of cancer cells. The expression of MAP3K11 and ATG4B was further associated with poor survival of OSCC, suggesting MAP3K11 could serve as a theranostic target of patients with OSCC.