stilbenes and Tongue-Neoplasms

Preventive measures against oral carcinogenesis are urgently warranted to lower the high morbidity and mortality associated with this malignancy worldwide. Here, we investigated the chemopreventive efficacy of grape seed extract (GSE) and resveratrol (Res) in 4-nitroquinoline-1-oxide (4NQO)-induced tongue tumorigenesis in C57BL/6 mice. Following 8 weeks of 4NQO exposure (100 µg/ml in drinking water), mice were fed with either control AIN-76A diet or diet containing 0.2% GSE (w/w) or 0.25% Res (w/w) for 8 subsequent weeks, while continued on 4NQO. Upon termination of the study at 16 weeks, tongue tissues were histologically evaluated for hyperplasia, dysplasia, and papillary lesions, and then analyzed for molecular targets by immunohistochemistry. GSE and Res feeding for 8 weeks, moderately decreased the incidence, but significantly prevented the multiplicity and severity of 4NQO-induced preneoplastic and neoplastic lesions, without any apparent toxicity. In tongue tissues, both 4NQO + GSE and 4NQO + Res treatment correlated with a decreased proliferation (BrdU labeling index) but increased apoptotic death (TUNEL-positive cells) as compared to the 4NQO group. Furthermore, tongue tissues from both the 4NQO + GSE and 4NQO + Res groups showed an increase in activated metabolic regulator phospho-AMPK (Thr172) and decreased autophagy flux marker p62. Together, these findings suggest that GSE and Res could effectively prevent 4NQO-induced oral tumorigenesis through modulating AMPK activation, and thereby, inhibiting proliferation and inducing apoptosis and autophagy, as mechanisms of their efficacy.

Topics: 4-Nitroquinoline-1-oxide; AMP-Activated Protein Kinases; Animals; Anticarcinogenic Agents; Apoptosis; Carcinogenesis; Carcinogens; Carcinoma, Squamous Cell; Female; Grape Seed Extract; In Situ Nick-End Labeling; Mice; Mice, Inbred C57BL; Resveratrol; Stilbenes; Tongue; Tongue Neoplasms

Naturally occurring agents, such as resveratrol, have been determined to benefit health. Numerous studies have demonstrated that resveratrol has antioxidative, cardioprotective, and neuroprotective properties. However, the effect of resveratrol exerts on the metastasis of oral cancer cells remains unclear. In this study, we investigated the effect the anti-invasive activity of resveratrol on a human oral cancer cell line (SCC-9) in vitro and the underlying mechanisms.. Cell viability was examined by MTT assay, whereas cell motility was measured by migration and wound-healing assays. Zymography, reverse-transcriptase polymerase chain reaction (PCR), and promoter assays confirmed the inhibitory effects of resveratrol on matrix metalloproteinase-9 (MMP-9) expression in oral cancer cells.. We established that various concentrations (0-100 μM) of resveratrol inhibited the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced migration capacities of SCC-9 cells and caused no cytotoxic effects. Zymography and Western blot analyses suggested that resveratrol inhibited TPA-induced MMP-9 gelatinolytic activity and protein expression. In addition, the results indicated that resveratrol inhibited the phosphorylation of c-Jun N-terminal kinase (JNK)1/2 and extracellular-signal-regulated kinase (ERK)1/2 involved in downregulating protein expression and the transcription of MMP-9.. In summary, resveratrol inhibited MMP-9 expression and oral cancer cell metastasis by downregulating JNK1/2 and ERK1/2 signals pathways and, thus, exerts beneficial effects in chemoprevention.

Topics: Antineoplastic Agents, Phytogenic; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Movement; Cell Survival; Down-Regulation; Enzyme Activation; Head and Neck Neoplasms; Humans; JNK Mitogen-Activated Protein Kinases; Matrix Metalloproteinase 9; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mouth Neoplasms; Neoplasm Invasiveness; Neoplasm Metastasis; Resveratrol; Signal Transduction; Squamous Cell Carcinoma of Head and Neck; Stilbenes; Tetradecanoylphorbol Acetate; Tongue Neoplasms

Hypoxia-inducible factor-1alpha (HIF-1alpha) is overexpressed in many human tumors and their metastases, and is closely associated with a more aggressive tumor phenotype. In this study, we investigated the effect of resveratrol, a natural product commonly found in grapes and various other fruits, on hypoxia-induced HIF-1alpha protein accumulation and vascular endothelial growth factor (VEGF) expression in human tongue squamous cell carcinomas and hepatoma cells. Our results showed that resveratrol significantly inhibited both basal level and hypoxia-induced HIF-1alpha protein accumulation in cancer cells, but did not affect HIF-1alpha mRNA levels. Pretreatment of cells with resveratrol significantly reduced hypoxia-induced VEGF promoter activities and VEGF expression at both mRNA and protein levels. The mechanism of resveratrol inhibition of hypoxia-induced HIF-1alpha accumulation seems to involve a gradually shortened half-life of HIF-1alpha protein caused by an enhanced protein degradation through the 26S proteasome system. In addition, resveratrol remarkably inhibited hypoxia-mediated activation of extracellular signal-regulated kinase 1/2 and Akt, leading to a marked decrease in hypoxia-induced HIF-1alpha protein accumulation and VEGF transcriptional activation. Functionally, we observed that resveratrol also significantly inhibited the hypoxia-stimulated invasiveness of cancer cells. These data suggested that HIF-1alpha/VEGF could be a promising drug target for resveratrol in the development of an effective chemopreventive and anticancer therapy in human cancers.

Topics: Antineoplastic Agents, Phytogenic; Carcinoma, Hepatocellular; Carcinoma, Squamous Cell; Cell Hypoxia; Cell Line, Tumor; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Liver Neoplasms; MAP Kinase Signaling System; Mitogen-Activated Protein Kinases; Neoplasm Invasiveness; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Resveratrol; RNA, Messenger; Stilbenes; Tongue Neoplasms; Transcriptional Activation; Vascular Endothelial Growth Factors

WST-1 (mitochondrial dehydrogenase activities). Arrest of cell growth, due to inhibition of DNA synthesis, may explain the leveling of toxicity between day 2 and 3 for a 3-day continuous exposure to resveratrol. Irreversible damage to cell proliferation was noted in S-G cells exposed to 75-150 microM resveratrol for 2 days and then subsequently maintained for another 3 days in resveratrol-free medium. The cytotoxicity of resveratrol was neither potentiated nor ameliorated in the presence of an hepatic S9 microsomal fraction. The cytotoxicity of hydrogen peroxide to S-G cells was lessened by N-acetyl-L-cysteine and quercetin, but not by resveratrol. For nitric oxide, only N-acetyl-L-cysteine reduced toxicity. The ability of resveratrol to function as an antioxidant was, therefore, not noted under these test conditions.

Topics: Antineoplastic Agents, Alkylating; Antineoplastic Agents, Phytogenic; Antioxidants; Bromodeoxyuridine; Carcinoma, Squamous Cell; Cell Count; Cell Division; Cell Line; Cell Survival; Coloring Agents; Cyclophosphamide; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Epithelial Cells; Fibroblasts; Gingiva; Humans; Indicators and Reagents; Keratinocytes; Neutral Red; Oxazines; Resveratrol; Stilbenes; Tongue Neoplasms; Xanthenes

Resveratrol and quercetin are polyphenols which have been detected in significant amounts in green vegetables, citrus fruits and red grape wines. Beneficial effects attributed to these compounds include anti-inflammatory, antiviral and antitumor properties. The effect of resveratrol and quercetin on growth of human oral cancer cells is unknown. Resveratrol and quercetin, in concentrations of 1 to 100 microM, were incubated in triplicates with human oral squamous carcinoma cells SCC-25 in DMEM-HAM's F-12 supplemented with fetal calf serum and antibiotics in an atmosphere of 5% CO2 in air at 37 degrees C for 72 h. Cell growth was determined by counting the number of viable cells with a hemocytometer. Cell proliferation was measured by means of incorporation of [3H]thymidine in nuclear DNA. Resveratrol at 10 and 100 microM induced significant dose-dependent inhibition in cell growth as well as in DNA synthesis. Quercetin exhibited a biphasic effect, stimulation at 1 and 10 microM, and minimal inhibition at 100 microM in cell growth and DNA synthesis. Combining 50 microM of resveratrol with 10, 25 and 50 microM of quercetin resulted in a gradual and significant increase in the inhibitory effect of quercetin on cell growth and DNA synthesis. We conclude that resveratrol or a combination of resveratrol and quercetin, in concentrations equivalent to that present in red wines, are effective inhibitors of oral squamous carcinoma cell (SCC-25) growth and proliferation, and warrant further investigation as cancer chemopreventive agents.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Antineoplastic Agents, Phytogenic; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Squamous Cell; Cell Division; Cisplatin; DNA, Neoplasm; Dose-Response Relationship, Drug; Humans; Indomethacin; Quercetin; Resveratrol; Stilbenes; Tongue Neoplasms; Tumor Cells, Cultured