Water-soluble 4-(dimethylaminomethyl)heliomycin exerts greater antitumor effects than parental heliomycin by targeting the tNOX-SIRT1 axis and apoptosis in oral cancer cells.

The antibiotic heliomycin (resistomycin), which is generated from Streptomyces resistomycificus, has multiple activities, including anticancer effects. Heliomycin was first described in the 1960s, but its clinical applications have been hindered by extremely low solubility. A series of 4-aminomethyl derivatives of heliomycin were synthesized to increase water solubility; studies showed that they had anti-proliferative effects, but the drug targets remained unknown. In this study, we conducted cellular thermal shift assays (CETSA) and molecular docking simulations to identify and validate that heliomycin and its water-soluble derivative, 4-(dimethylaminomethyl)heliomycin (designated compound 4-dmH) engaged and targeted with sirtuin-1 (SIRT1) in p53-functional SAS and p53-mutated HSC-3 oral cancer cells. We further addressed the cellular outcome of SIRT1 inhibition by these compounds and found that, in addition to SIRT1, the water-soluble 4-dmH preferentially targeted a tumor-associated NADH oxidase (tNOX, ENOX2). The direct binding of 4-dmH to tNOX decreased the oxidation of NADH to NAD+ which diminished NAD+-dependent SIRT1 deacetylase activity, ultimately inducing apoptosis and significant cytotoxicity in both cell types, as opposed to the parental heliomycin-induced autophagy. We also observed that tNOX and SIRT1 were both upregulated in tumor tissues of oral cancer patients compared to adjacent normal tissues, suggesting their clinical relevance. Finally, the better therapeutic efficacy of 4-dmH was confirmed in tumor-bearing mice, which showed greater tNOX and SIRT1 downregulation and tumor volume reduction when treated with 4-dmH compared to heliomycin. Taken together, our in vitro and in vivo findings suggest that the multifaceted properties of water-soluble 4-dmH enable it to offer superior antitumor value compared to parental heliomycin, and indicated that it functions through targeting the tNOX-NAD+-SIRT1 axis to induce apoptosis in oral cancer cells.

The neddylation inhibitor MLN4924 inhibits proliferation and triggers apoptosis of oral cancer cells but not for normal cells.

Increased neddylation benefits the survival of several types of cancer cells. The inhibition of neddylation has the potential to exert anticancer effects but is rarely assessed in oral cancer cells. This study aimed to investigate the antiproliferation potential of a neddylation inhibitor MLN4924 (pevonedistat) for oral cancer cells. MLN4924 inhibited the cell viability of oral cancer cells more than that of normal oral cells (HGF-1) with 100% viability, that is, IC50 values of oral cancer cells (CAL 27, OC-2, and Ca9-22) are 1.8, 1.4, and 1.9 µM. MLN4924 caused apoptotic changes such as the subG1 accumulation, activation of annexin V, pancaspase, and caspases 3/8/9 of oral cancer cells at a greater rate than in normal oral cells. MLN4924 induced greater oxidative stress in oral cancer cells compared to normal cells by upregulating reactive oxygen species and mitochondrial superoxide and depleting the mitochondrial membrane potential and glutathione. In oral cancer cells, preferential inductions also occurred for DNA damage (γH2AX and 8-oxo-2'-deoxyguanosine). Therefore, this investigation demonstrates that MLN4924 is a potential anti-oral-cancer agent showing preferential inhibition of apoptosis and promotion of DNA damage with fewer cytotoxic effects on normal cells.

Transcriptome of Oral Cancer Cells Adapted to Suspension Culture Is Potentially Related to Cancer Progressive Phenotypes.

BACKGROUND/AIM: Cervical lymph node metastasis worsens oral cancer prognosis. Cancer cells with high metastatic ability can delay or resist apoptosis and survive in the floating condition during circulation. The involved genes and pathways in this process remain largely unknown. This study aimed to establish an oral cancer cell line adapted to suspension culture by in vitro selection and perform gene expression analysis. MATERIALS AND METHODS: The oral cancer cell subline adapted to suspension culture was isolated by in vitro selection from the oral cancer cell line, HSC-3. The transcriptome profiles of HSC-3 and its subline were compared using gene expression microarrays. Gene Ontology (GO) enrichment analysis, Gene Set Enrichment Analysis (GSEA), and Ingenuity Pathway Analysis (IPA) were performed to predict the involved pathways and molecules in cancer progression. RESULTS: The subline was designated as HSC-3S5 The cellular viability of HSC-3S5 cells at the suspension culture was higher than that of HSC-3 cells. A total of 961 genes were differentially expressed between HSC-3 and HSC-3S5 cells under the threshold cut-off (FDR-adjusted p-value of <0.05 and absolute fold change of >1.5). GO terms, such as growth regulation, were enriched in the DEGs. GSEA revealed the association between the DEGs and significant gene sets, including metastasis and stemness. IPA predicted that the proliferation-related pathways were enhanced while the apoptotic pathway was inhibited in HSC-3S5 cells compared to HSC-3 cells. CONCLUSION: Our transcriptome analysis revealed several potentially activated pathways and molecules in the floating-adapted oral cancer cells and indicated molecular implications for cancer progression.

Exploring stage­specific embryonic antigen 3 involvement in oral cancer progression and as a potential target for taxane­based chemotherapy.

Despite significant advancements in therapeutic approaches, oral neoplasms remain formidable and life­threatening conditions that affect a substantial number of individuals worldwide. Within oral malignancies, a subset of cancer stem cells (CSCs) represent a crucial population responsible for tumor initiation and progression. The identification of reliable markers for the detection and characterization of CSCs in solid tumors, particularly in the context of oral cancers, remains an ongoing challenge. Stage­specific embryonic antigen 3 (SSEA3), previously associated with mesenchymal stem cells and linked to the progression of breast neoplasms and poor prognosis, has yet to be comprehensively elucidated in the context of oral malignancies. The present study aimed to investigate the expression and properties of SSEA3 in 16 distinct subsets of human oral neoplastic cell lines, classified as either CD44 positive (+) or CD44 negative (­). For the first time, SSEA3 was examined as an indicator of tumorigenicity and resistance to taxane­derived chemotherapeutic agents. In the majority of oral neoplastic cell lines analyzed, SSEA3 was expressed in a small population of CD44(+) cells. Significantly, SSEA3(+) cells exhibited heightened proliferative activity and upregulated expression of genes associated with stem cells compared with SSEA3(­) cells. The aforementioned findings suggested that SSEA3 may contribute to the evolution and progression of oral malignancies by fostering tumor growth. Furthermore, SSEA3(+) cells displayed increased sensitivity to taxane­based pharmaceuticals, indicating the potential for SSEA3 to be a viable target in the treatment schema for oral cavity neoplasms. In conclusion, the present study provides novel insight into the role of SSEA3 in the progression and management of oral neoplasms, potentially paving the way for more effective therapeutic approaches.

Action of econazole on Ca2+ levels and cytotoxicity in OC2 human oral cancer cells.

Background/purpose: Econazole is an antifungal drug. Antifungal activity of econazole against non-dermatophyte molds was reported. Econazole inhibited Ca2+ channels and stimulated cytotoxicity in lymphoma and leukemia cells. Ca2+ cations are crucial second envoy that triggers various processes. This research was aimed to investigate action of econazole on Ca2+ levels and cytotoxicity in OC2 human oral cancer cells. Materials and methods: Cytosolic Ca2+ levels ([Ca2+]i) were detected employing fura-2 as a probe in a RF-5301PC spectrofluorophotometer (Shimadzu). Cytotoxicity was determined using 4-[3-[4-lodophenyl]-2-4(4-nitrophenyl)-2H-5-tetrazolio-1,3-benzene disulfonate] (WST-1) to detect fluorescence changes. Results: Econazole at 10-50 µmol/L provoked [Ca2+]i raises. Forty % of 50 µml//L econazole-induced signal was diminished when external Ca2+ was eliminated. The Ca2+ influx provoked by econazole was suppressed by different degrees by store-induced Ca2+ influx suppressors SKF96365 and nifedipine; GF109203X (a protein C [PKC] inhibitor); an extracellular signaling pathway (ERK) 1/2 blocker PD98059, and phospholipase A2 suppressor aristolochic acid, but was enhanced by phorbol 12-myristate 13 acetate (PMA; a PKC activator) by 18%. Without external Ca2+, econazole-caused [Ca2+]i raises were abolished by thapsigargin. In contrast, econazole partially suppressed the [Ca2+]i raises caused by thapsigargin. U73122 fell short to change econazole-caused [Ca2+]i responses. Econazole (10-70 µmol/L) elicited cytotoxicity in a dose-dependent fashion. Blockade of 50 µmol/L econazole-induced [Ca2+] rises with BAPTA/AM enhanced econazole-induced cytotoxicity by 72%. Conclusion: Econazole evoked [Ca2+]i raises and provoked cytotoxicity in a concentration-dependent manner in OC2 human oral cancer cells. In Ca2+-containing solution, BAPTA/AM enhanced 50 µmol/L econozole-induced cytotoxicity.

Green Fabrication of silver nanoparticles by leaf extract of Byttneria Herbacea Roxb and their promising therapeutic applications and its interesting insightful observations in oral cancer.

The present research was carried out to look into therapeutic insight of biosynthesized silver nanoparticles (AgNPs) by leaf extract of Byttneria herbacea Roxb (BH). The analysis of biosynthesized BH-AgNPs by UV-visible spectroscopy shows an intense surface plasmon resonance (SPR) peak at 422 nm initially and 437 nm after 30 min which certainly reveals the formation of BH-AgNPs. Fourier Infra-red Spectroscopy (FT-IR) reveals that BH-AgNPs are biosynthesized by using different bioactive compounds like O-H stretch of free hydroxyl alcohol and phenols, N-H bond of primary amines present in the leaf extract. Transmission Electron Microscope (TEM) analysis revealed that BH-AgNPs are almost spherical in nature with an average size range from of 2 nm to 12 nm. The particle size analysis by Dynamic Light Scattering (DLS) reveals that the BH-AgNPs are poly-dispersed in nature with an average size of 8 nm ± 2 nm, with a negative zeta potential value of -21 mV which reveals the biosynthesized BH-AgNPs are very stable. The BH-AgNPs (Byttneria herbacea -AgNPs) revealed excellent free radical scavenging activity and exceptional antimicrobial activity. The anti-proliferative and cytotoxic studies in KB oral cancer cells revealed biosynthesized BH-AgNPs can employ as future novel therapeutic agents in cancer treatment and other biomedical applications.

Sodium arsenite and dimethylarsenic acid induces apoptosis in OC3 oral cavity cancer cells.

Although arsenic is an environmental toxicant, arsenic trioxide (ATO) is used to treat acute promyelocytic leukemia (APL) with anticancer effects. Studies have demonstrated oral cancer is in the top 10 cancers in Taiwan. High rate of oral cancers is linked to various behaviors, such as excessive alcohol consumption and tobacco use. Similarly, betel chewing is a strong risk factor in oral cancer. In the present study, oral squamous carcinoma OC3 cells were investigated with the treatments of sodium arsenite (NaAsO2) and dimethylarsenic acid (DMA), respectively, to examine if arsenic compounds have anti­cancer efforts. It was found that 1 µM NaAsO2 and 1 mM DMA for 24 h induced rounded contours with membrane blebbing phenomena in OC3 cells, revealing cell apoptotic characteristics. In addition, NaAsO2 (10­100 µM) and DMA (1­100 mM) significantly decreased OC3 cell survival. In cell cycle regulation detected by flow cytometry, NaAsO2 and DMA significantly augmented percentage of subG1 and G2/M phases in OC3 cells, respectively. Annexin V/PI double staining assay was further used to confirm NaAsO2 and DMA did induce OC3 cell apoptosis. In mechanism investigation, western blotting assay was applied and the results showed that NaAsO2 and DMA significantly induced phosphorylation of JNK, ERK1/2 and p38 and then the cleavages of caspase­8, ­9, ­3 and poly ADP­ribose polymerase (PARP) in OC3 cells, dynamically. In conclusion, NaAsO2 and DMA activated MAPK pathways and then apoptotic pathways to induce OC3 oral cancer cell apoptosis.

Bis(chloroacetamidino)-Derived Heteroarene-Fused Anthraquinones Bind to and Cause Proteasomal Degradation of tNOX, Leading to c-Flip Downregulation and Apoptosis in Oral Cancer Cells.

Anthraquinone-based intercalating compounds, namely doxorubicin and mitoxantrone, have been used clinically based on their capacity to bind DNA and induce DNA damage. However, their applications have been limited by side effects and drug resistance. New-generation anthraquinone derivatives fused with different heterocycles have been chemically synthesized and screened for higher anticancer potency. Among the compounds reported in our previous study, 4,11-bis(2-(2-chloroacetamidine)ethylamino)anthra[2,3-b]thiophene-5,10-dione dihydrochloride (designated 2c) was found to be apoptotic, but the direct cellular target responsible for the cytotoxicity remained unknown. Here, we report the synthesis and anticancer properties of two other derivatives, 4,11-bis(2-(2-chloroacetamidine)ethylamino)naphtho[2,3-f]indole-5,10-dione dihydrochloride (2a) and 4,11-bis(2-(2-chloroacetamidine)ethylamino)-2-methylanthra[2,3-b]furan-5,10-dione dihydrochloride (2b). We sought to identify and validate the protein target(s) of these derivatives in oral cancer cells, using molecular docking simulations and cellular thermal shift assays (CETSA). Our CETSA results illustrate that these derivatives targeted the tumor-associated NADH oxidase (tNOX, ENOX2), and their direct binding downregulated tNOX in p53-functional SAS and p53-mutated HSC-3 cells. Interestingly, the compounds targeted and downregulated tNOX to reduce SIRT1 deacetylase activity and increase Ku70 acetylation, which triggers c-Flip ubiquitination and induces apoptosis in oral cancer cells. Together, our data highlight the potential value of these heteroarene-fused anthraquinones in managing cancer by targeting tNOX and augmenting apoptosis.

Antioral Cancer Effects by the Nitrated [6,6,6]Tricycles Compound (SK1) In Vitro.

A novel nitrated [6,6,6]tricycles-derived compound containing nitro, methoxy, and ispropyloxy groups, namely SK1, was developed in our previous report. However, the anticancer effects of SK1 were not assessed. Moreover, SK1 contains two nitro groups (NO2) and one nitrogen-oxygen (N-O) bond exhibiting the potential for oxidative stress generation, but this was not examined. The present study aimed to evaluate the antiproliferation effects and oxidative stress and its associated responses between oral cancer and normal cells. Based on the MTS assay, SK1 demonstrated more antiproliferation ability in oral cancer cells than normal cells, reversed by N-acetylcysteine. This suggests that SK1 causes antiproliferation effects preferentially in an oxidative stress-dependent manner. The oxidative stress-associated responses were further validated, showing higher ROS/MitoSOX burst, MMP, and GSH depletion in oral cancer cells than in normal cells. Meanwhile, SK1 caused oxidative stress-causing apoptosis, such as caspases 3/8/9, and DNA damages, such as γH2AX and 8-OHdG, to a greater extent in oral cancer cells than in normal cells. Siilar to cell viability, these oxidative stress responses were partially diminished by NAC, indicating that SK1 promoted oxidative stress-dependent responses. In conclusion, SK1 exerts oxidative stress, apoptosis, and DNA damage to a greater extent to oral cancer cells than in normal cells.

Z-Ligustilide Induces c-Myc-Dependent Apoptosis via Activation of ER-Stress Signaling in Hypoxic Oral Cancer Cells.

Z-ligustilide (or ligustilide) is found in Angelica sinensis (Oliv.) Diels and may exert potential benefits in cancer treatment. Previous research has reported that ligustilide has anti-cancer effects on several types of cancer cells. However, studies of ligustilide on oral cancer cells have not been reported, especially under hypoxic conditions. This study focuses on the molecular mechanism of ligustilide-induced apoptosis in hypoxic oral cancer cells. We found that in hypoxic TW2.6 cells, ligustilide inhibited cell migration and induced caspase-dependent apoptosis. Accumulation of c-Myc accompanied by BH3-only members suggests that ligustilide may induce c-Myc-dependent apoptosis. In addition, we reported that ligustilide has an effect on ER-stress signaling. By using inhibitors of c-Myc, IRE1α, and ER-stress inhibitors, we found that cell morphologies or cell viability were rescued to some degree. Moreover, ligustilide is able to increase the expression of γ-H2AX and enhance the occurrence of DNA damage in oral cancer cells after radiation treatment. This result suggests that ligustilide has potential as a radiation sensitizer. Altogether, we propose that ligustilide may induce c-Myc-dependent apoptosis via ER-stress signaling in hypoxic oral cancer cells.

Oral cancer cells affect pancreatic ß-cell function through transmissible endoplasmic reticulum stress.

OBJECTIVES: In this study, we aimed to investigate whether oral cancer cells affect pancreatic ß-cells function through transmissible endoplasmic reticulum stress (TERS). METHODS: Tunicamycin (TM) was selected as the endoplasmic reticulum stress (ERS) inducer. The human oral cancer cell lines CAl-27 and SCC-25 were selected as the donor cells, and mouse insulinoma 6 (MIN6) cell lines were chosen as the recipient cells. Quantitative real-time polymerase chain reaction (qPCR) and Western blot (WB) analysis were used to detect ERS markers and insulin expression. The TdT-mediated dUTP nick-end labeling (TUNEL) method was applied to detect apoptosis levels. The clone formation method was utilized to detect cell proliferation capability. The secretory function of pancreatic ß-cells was detected with an enzyme linked immunosorbent assay (ELISA) kit and a bicinchoninic acid (BCA) kit. RESULTS: The MIN6 cells were subjected to TM stimulation. qPCR and WB analysis revealed that ERS markers were upregulated. This result implied that the MIN6 cells can induce ERS. The supernatant of oral cancer cells under ERS was added to the MIN6 cells. qPCR and WB analysis showed that the oral cancer cells that had been subjected to ERS could induce ERS in the MIN6 cells, that is, the phenomenon of TERS occurred. The TUNEL assay indicated that the apoptosis of the MIN6 cells increased under TERS. The clone formation assay demonstrated that the proliferation capability of the MIN6 cells decreased under TERS. qPCR and WB analysis revealed that under TERS, insulin synthesis by the MIN6 cells decreased and insulin synthesis was inhibited at the translation level. The ELISA and BCA kits demonstrated that insulin secretion by the MIN6 cells was reduced under TERS. CONCLUSIONS: Oral cancer cells can affect pancreatic ß-cells through TERS, resulting in increased apoptosis, decreased viability, and reduced insulin secretion and synthesis capability.

ISG20 is overexpressed in clinically relevant radioresistant oral cancer cells.

Global standard fractionated radiotherapy (RT) for the treatment of malignancies consists of X-ray irradiation with 2-Gy/day, 5 days a week for 5-7 weeks. Recently, clinically relevant radioresistant (CRR) cells were first defined as cells that can continue to grow even after exposure to daily 2-Gy of X-rays for more than 30 days in vitro. To analyze the characteristics of radioresistant cancer cells, CRR oral cancer cells (CRR-OCCs) were established, and the expression level of interferon-stimulated exonuclease gene 20 (ISG20) was evaluated with qRT-PCR and immunohistochemical analysis. Our result revealed that the expression level of both ISG20 mRNA and its protein in CRR-OCCs were higher than those of corresponding parental cells. We concluded that ISG20 was statistically overexpressed in CRR-OCCs. ISG20 overexpression may be necessary for the radioresistant phenotype in CRR-OCCs, and targeting ISG20 of human cancer cells may lead to more efficient RT or chemoradiotherapy for eliminating cancer.

Asparaginase induces selective dose- and time-dependent cytotoxicity, apoptosis, and reduction of NFκB expression in oral cancer cells.

Asparaginase is fundamental to the treatment of haematological malignancies. However, little has been studied on the effects that asparaginase could exert on solid tumours. Thus, this study aimed to evaluate the effects of asparaginase on an oral carcinoma cell line. The cytotoxicity of asparaginase in SCC-9 (tongue squamous cell carcinoma) and HaCaT (human keratinocyte) cell lines was evaluated with MTT cell viability assay. The cells were treated with asparaginase at 0.04, 0.16, 0.63, 1.0, 1.5, 2.5, and 5.0 IU/mL. Dose-response curves and IC50 values were obtained and the Tumour Selectivity Index (TSI) was calculated. The effect of asparaginase on procaspase-3 and nuclear factor κB (NFκB) expression was evaluated with western blot because it was reported that the overexpression of NFκB has been shown to contribute to tumour cell survival, proliferation, and migration. Caspase 3/7 staining was performed to identify cell death using flow cytometry. Effective asparaginase concentrations were lower for SCC-9 cells when compared to HaCaT cells. The cytotoxicity results at 48 and 72 hours were significantly different for SCC-9 cells. The TSI indicated that asparaginase was selective for the tumour cells. A decrease in procaspase-3 and NFκB protein levels was observed in SCC-9 cells. Furthermore, asparaginase resulted in significant apoptosis after 48 and 72 hours. Based on these results, asparaginase was cytotoxic in a dose- and time-dependent manner, induces apoptosis, and reduces NFκB expression in oral cancer cells. These results encourage further studies on the effectiveness of this enzyme as a treatment for solid tumours, especially head and neck cancer.

Gefitinib and curcumin-loaded nanoparticles enhance cell apoptosis in human oral cancer SAS cells in vitro and inhibit SAS cell xenografted tumor in vivo.

Curcumin (Cur), a natural product, has been shown to have anti-tumor activities in many human cancer cells. Gefitinib (Gef) is a clinical drug for cancer patients. However, there is no available information to show whether Gef/Cur nanoparticles (NPs) increased cell apoptosis and anti-tumor effects on xenograft mice model in vivo. In this study, γ-polyglutamic acid-coated nanoparticles loaded with Gef and Cur (γ-PGA-Gef/Cur NPs) were developed and its physicochemical properties and antitumor effects were investigated in vitro and in vivo. The γ-PGA-Gef/Cur NPs showed 548.5 ±â€¯93.7 nm in diameter and -40.3 ±â€¯3.87 mV on surface charge. The loading efficiencies of Gef and Cur were 89.5 and 100%, respectively. γ-PGA-Gef/Cur NPs could be internalized into SAS cells and significantly decreased total cell viability of SAS cells. Western blotting results indicated that both free Gef/Cur and γ-PGA-Gef/Cur NPs induced apoptotic cell death via caspase- and mitochondria-dependent pathways. In vivo studies indicated that treatments of PLGA NPs, free Gef/Cur, and γ-PGA-Gef/Cur NPs did not significantly affect appearances and bodyweights of mice. But the γ-PGA-Gef/Cur NPs significantly suppressed tumor size when comparing to free Gef/Cur-treated group. The nanoparticles developed in this study may be used as a potential therapy for oral cancer.

Action of chlorzoxazone on Ca2+movement and viability in human oral cancer cells.

Chlorzoxazone is a skeletal muscle relaxant. However, the effect of chlorzoxazone on intracellular Ca2+ concentrations ([Ca2+]i) in oral cancer cells is unclear. This study examined whether chlorzoxazone altered Ca2+ signaling and cell viability in OC2 human oral cancer cells. [Ca2+]iin suspended cells was measured using the fluorescent Ca2+-sensitive dye fura-2. Cell viability was examined by water-soluble tetrazolium-1 assay. Chlorzoxazone (250-1000 µM) induced [Ca2+]irises in a concentration-dependent manner. Ca2+ removal reduced the signal by approximately 50%. Mn2+ has been shown to enter cells through similar mechanisms as Ca2+ but quenches fura-2 fluorescence at all excitation wavelengths. Chlorzoxazone (1000 µM) induced Mn2+ influx, suggesting that Ca2+ entry occurred. Chlorzoxazone-induced Ca2+ entry was inhibited by 20% by inhibitors of store-operated Ca2+ channels and protein kinase C (PKC) modulators. In Ca2+-free medium, treatment with the endoplasmic reticulum Ca2+ pump inhibitor thapsigargin (TG) inhibited chlorzoxazone-evoked [Ca2+]irises by 88%. Conversely, treatment with chlorzoxazone-suppressed TG-evoked [Ca2+]irises 75%. Chlorzoxazone induced [Ca2+]irises by exclusively releasing Ca2+ from the endoplasmic reticulum. Inhibition of phospholipase C (PLC) with U73122 did not alter chlorzoxazone-induced [Ca2+]irises. PLC activity was not involved in chlorzoxazone-evoked [Ca2+]irises. Chlorzoxazone at 200-700 µM decreased cell viability, which was not reversed by pretreatment with Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid/acetoxy methyl. In sum, in OC2 cells, chlorzoxazone induced [Ca2+]irises by evoking PLC-independent Ca2+ release from the endoplasmic reticulum and Ca2+ entry via PKC-sensitive store-operated Ca2+ entry. Chlorzoxazone also caused Ca2+-independent cell death. Since [Ca2+]irises play a triggering or modulatory role in numerous cellular phenomena, the effect of chlorzoxazone on [Ca2+]iand cell viability should be taken into account in other in vitro studies.

Cis-3-O-p-hydroxycinnamoyl Ursolic Acid Induced ROS-Dependent p53-Mediated Mitochondrial Apoptosis in Oral Cancer Cells.

Cis-3-O-p-hydroxycinnamoyl ursolic acid (HCUA), a triterpenoid compound, was purified from Elaeagnus oldhamii Maxim. This traditional medicinal plant has been used for treating rheumatoid arthritis and lung disorders as well as for its anti-inflammation and anticancer activities. This study aimed to investigate the anti-proliferative and apoptotic-inducing activities of HCUA in oral cancer cells. HCUA exhibited anti-proliferative activity in oral cancer cell lines (Ca9-22 and SAS cells), but not in normal oral fibroblasts. The inhibitory concentration of HCUA that resulted in 50% viability was 24.0 µM and 17.8 µM for Ca9-22 and SAS cells, respectively. Moreover, HCUA increased the number of cells in the sub-G1 arrest phase and apoptosis in a concentration-dependent manner in both oral cancer cell lines, but not in normal oral fibroblasts. Importantly, HCUA induced p53-mediated transcriptional regulation of pro-apoptotic proteins (Bax, Bak, Bim, Noxa, and PUMA), which are associated with mitochondrial apoptosis in oral cancer cells via the loss of mitochondrial membrane potential. HCUA triggered the production of intracellular reactive oxygen species (ROS) that was ascertained to be involved in HCUA-induced apoptosis by the ROS inhibitors YCG063 and N-acetyl-L-cysteine. As a result, HCUA had potential antitumor activity to oral cancer cells through eliciting ROS-dependent and p53-mediated mitochondrial apoptosis. Overall, HCUA could be applicable for the development of anticancer agents against human oral cancer.

Cis-3-O-p-hydroxycinnamoyl Ursolic Acid Induced ROS-Dependent p53-Mediated Mitochondrial Apoptosis in Oral Cancer Cells

Cis-3-O-p-hydroxycinnamoyl ursolic acid (HCUA), a triterpenoid compound, was purified from Elaeagnus oldhamii Maxim. This traditional medicinal plant has been used for treating rheumatoid arthritis and lung disorders as well as for its anti-inflammation and anticancer activities. This study aimed to investigate the anti-proliferative and apoptotic-inducing activities of HCUA in oral cancer cells. HCUA exhibited anti-proliferative activity in oral cancer cell lines (Ca9-22 and SAS cells), but not in normal oral fibroblasts. The inhibitory concentration of HCUA that resulted in 50% viability was 24.0 µM and 17.8 µM for Ca9-22 and SAS cells, respectively. Moreover, HCUA increased the number of cells in the sub-G1 arrest phase and apoptosis in a concentration-dependent manner in both oral cancer cell lines, but not in normal oral fibroblasts. Importantly, HCUA induced p53-mediated transcriptional regulation of pro-apoptotic proteins (Bax, Bak, Bim, Noxa, and PUMA), which are associated with mitochondrial apoptosis in oral cancer cells via the loss of mitochondrial membrane potential. HCUA triggered the production of intracellular reactive oxygen species (ROS) that was ascertained to be involved in HCUA-induced apoptosis by the ROS inhibitors YCG063 and N-acetyl-L-cysteine. As a result, HCUA had potential antitumor activity to oral cancer cells through eliciting ROS-dependent and p53-mediated mitochondrial apoptosis. Overall, HCUA could be applicable for the development of anticancer agents against human oral cancer.

Fermented Lingonberry Juice Inhibits Oral Tongue Squamous Cell Carcinoma Invasion In Vitro Similarly to Curcumin.

BACKGROUND: Oral tongue squamous cell carcinoma (OTSCC) cells are highly proliferative and invasive. Lingonberry contains several polyphenolic compounds similar to curcumin. We hypothesize that fermented lingonberry juice (FLJ) has an anti-invasive and anti-proliferative effect on OTSCC cells similarly to curcumin, which is known to be anti-carcinogenic. MATERIALS AND METHODS: FLJ, curcumin dissolved in ethanol, or curcumin loaded in Candida extracellular vesicles (EVs) were added to more (HSC-3) and less aggressive (SCC-25) OTSCC cells. Cell proliferation was measured with a 5-bromo-2'-deoxyuridine kit and invasion in the three-dimensional Myogel spheroid assay. Statistical analyses were completed with one-way ANOVA and Bonferroni post-hoc testing. RESULTS: Both FLJ and curcumin significantly reduced the proliferation and invasion of HSC-3 and SCC-25 cells. The effects of curcumin were not improved when cells were treated with curcumin loaded within EVs. CONCLUSION: Our results suggest that FLJ, like curcumin, has an anti-carcinogenic effect on aggressive OTSCC cells in vitro.

Antioxidant Properties of Fractions for Unripe Fruits of Capsicum annuum L. var. Conoides.

BACKGROUND: Capsicum plant, especially for C. annuum, is an abundant resource for bioactive antioxidants, but few studies have examined the unripe fruit part of the Capsicum plant. OBJECTIVE: MeOH extract of unripe fruits of C. annuum L. var. conoides (UFCA) was chromatographed over a silica gel column using a gradient of CH2Cl2/MeOH as eluent to produce 9 fractions. Antioxidant activities are evaluated along with cell viabilities of 9 fractions of UFCA. METHOD: The antioxidant properties were analyzed in terms of total phenol content (TPC), total flavonoid content (TFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, 2,2-azinobis (3-ethyl-benzothiazoline-6- sulfonic acid) (ABTS) radical scavenging, ferric reducing, and ferrous ion-chelating ability. The cell viability of human oral cancer cells (Ca9-22) was measured by 3-(4,5-dimethylthiazol-2-yl)-(3-carboxymethoxyphenyl)-2- (4-sulphophenyl)-2H-tetrazolium (MTS) assay. RESULTS: Except for TFC, fractions (Frs.) 1 and 2 showed the lowest level of these antioxidant properties. Frs. 3 to 9 showed dose-responsive induction for antioxidant effects. Fr. 8 and Fr. 5 respectively showed the highest levels of TPC and TFC for 1162 ± 11 gallic acid equivalents (GAE) (mg)/UFCA (g) and 1295 ± 32 quercetin equivalents (QCE) (mg)/UFCA (g). The cell viability of Fr. 3 was moderately decreased (78.2%) while those of Frs. 4, 5, and 9 were dramatically decreased (55.6, 57.8, and 46.8%, respectively) in oral cancer Ca9-22 cells. UFCA-derived 14 compounds/mixtures derived from Frs. 1, 2, 3, 4, and 8 displayed differential antioxidant performance for these analyses. CONCLUSION: Taken together, fractions of UFCA displayed diverse antioxidant and anticancer effects for oral cancer cells. Some fractions of UFCA may be potent natural antioxidant supplements for antioral cancer cell treatment.

Casticin impairs cell growth and induces cell apoptosis via cell cycle arrest in human oral cancer SCC-4 cells.

Casticin, a polymethoxyflavone, present in natural plants, has been shown to have biological activities including anti-cancer activities. Herein, we investigated the anti-oral cancer activity of casticin on SCC-4 cells in vitro. Viable cells, cell cycle distribution, apoptotic cell death, reactive oxygen species (ROS) production, and Ca2+ production, levels of ΔΨm and caspase activity were measured by flow cytometric assay. Cell apoptosis associated protein expressions were examined by Western blotting and confocal laser microscopy. Results indicated that casticin induced cell morphological changes, DNA condensation and damage, decreased the total viable cells, induced G2 /M phase arrest in SCC-4 cells. Casticin promoted ROS and Ca2+ productions, decreases the levels of ΔΨm , promoted caspase-3, -8, and -9 activities in SCC-4 cells. Western blotting assay demonstrated that casticin affect protein level associated with G2/M phase arrest and apoptosis. Confocal laser microscopy also confirmed that casticin increased the translocation of AIF and cytochrome c in SCC-4 cells. In conclusion, casticin decreased cell number through G2 /M phase arrest and the induction of cell apoptosis through caspase- and mitochondria-dependent pathways in SCC-4 cells.