u-0126 and Mouth-Neoplasms

To explore the role of RN181 in the pathogenesis of oral squamous cell carcinoma (OSCC) cells via mediating ERK/MAPK signaling.. The expression of RN181 was detected in OSCC tissues and cells. CAL27 and SCC-15 cells were divided into Control, Empty, RN181, si-RN181, U0126 (an inhibitor of ERK/MAPK pathway) and si-RN181 + U0126 groups. MTT was used to determine cell proliferation, flow cytometry to determine cell cycle and apoptosis, Transwell assay and wound healing test to determine cell invasion and migration, respectively. Western blotting was used to measure the protein expression. Furthermore, a xenograft tumor model was established to observe the effect of RN181 on the in vivo growth of OSCC cells.. RN181 was down-regulated in OSCC tissues and cells. As compared to the Control group, CAL27 and SCC-15 cells in the RN181 group and U0126 group presented with decreases in the proliferation, invasion and migration, but increases in the cell ratio at the G0/G1 phase and apoptosis, while the p-ERK 1/2/ERK 1/2 was down-regulated. Cells in the si-RN181 group manifested the opposite changes. U0126 could reverse the positive effect of si-RN181 on the growth of OSCC cells. In vivo experiment demonstrated that the tumor growth and weight were reduced in the RN181 group, with decreased Ki67 positive expression and elevated TUNEL positive cells.. RN181 was down-regulated in OSCC, and it could inhibit the proliferation, invasion and migration, cause the G0/G1 arrest, while promote the apoptosis of OSCC cells via inhibiting ERK/MAPK pathway.

Topics: Adult; Aged; Animals; Apoptosis; Butadienes; Cell Cycle; Cell Line, Tumor; Cell Movement; Cell Proliferation; Extracellular Signal-Regulated MAP Kinases; Female; Gene Expression Profiling; Humans; Ki-67 Antigen; Male; MAP Kinase Signaling System; Mice; Mice, Nude; Middle Aged; Mouth Neoplasms; Neoplasm Transplantation; Nitriles; Signal Transduction; Squamous Cell Carcinoma of Head and Neck; Ubiquitin-Protein Ligases; Wound Healing

Cancer is the most common cause of death worldwide with approximately one third of people being diagnosed with cancer in their lifetime. Pinostilbene hydrate (PSH) A methylated derivative of resveratrol Has been reported to possess antioxidative Cardioprotective and anticancer properties. However the antimetastatic effect of pinostilbene in oral squamous cell carcinoma (OSCC) remains unknown.. In this study We investigated the effect of PSH on antimetastatic activity and the relevant signaling pathways underlying mechanisms of SCC-9 SAS and HSC-3 oral cancer cell lines by MTT assay Wound healing Transwell assay Zymography and western blot analysis.. Our findings indicated that PSH inhibits migration and invasion ability by reducing the protein activity and expression of matrix metalloproteinases-2 (MMP-2) in all three cell lines. Moreover • The phosphorylation of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinases (p38) had significant inhibitory effects in the presence of PSH in the SCC9 and SAS cell lines. A combination of ERK1/2 and p38 inhibitors with PSH also reduced the migration and activity of MMP-2 in the SCC9 and SAS cell lines.. This study demonstrated that PSH suppresses MMP-2 enzymatic activity by downregulating the p38/ERK1/2 pathway and that it might be a promising agent for preventing OSCC cell metastasis.

Topics: Butadienes; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Movement; Cell Survival; Down-Regulation; Humans; Imidazoles; Matrix Metalloproteinase 2; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mouth Neoplasms; Nitriles; p38 Mitogen-Activated Protein Kinases; Pyridines; Signal Transduction; Stilbenes

Constitutive activation of the signal transducer and activator of transcription 3 (STAT3) signaling pathway possesses confirmed oncogenic potential in oral squamous cell carcinoma (OSCC). Crosstalk with other molecular pathways contributes to STAT3 regulation in cancer. The effects of mitogen-activated protein kinases (MAPKs) and particularly extracellular signal-regulated kinase 1/2 (Erk1/2) on STAT3 signaling in OSCC have not been thoroughly investigated. The present study examined the effects of Erk1/2 modulation on STAT3 signaling and cell growth in OSCC cells. Constitutive expression levels of phosphorylated (tyrosine and serine) and total STAT3, Erk1/2 and cyclin D1 were assessed in OSCC cell lines. Erk1/2 modulation was achieved by pharmacological agents; siRNA silencing against Erk1/2 was also performed. Cell proliferation and viability were assessed. Erk1/2 inhibition with either U0126 treatment or specific siRNA silencing resulted in decreases in p-ser STAT3 and cyclin D1 levels and increases in p-tyr STAT3 in OSCC cells. Moreover, Erk1/2 inhibition resulted in a dose-dependent reduction in OSCC cell growth and viability. Erk1/2 induction had the opposite effects. Taken together, these results are supportive of an active crosstalk between the oncogenic Erk1/2 and STAT3 pathways in OSCC, the significance of which requires further investigation.

Topics: Butadienes; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclin D1; Humans; MAP Kinase Signaling System; Mouth Neoplasms; Nitriles; Phosphorylation; RNA, Small Interfering; STAT3 Transcription Factor

Granulocyte colony-stimulating factor (G-CSF) affects granulopoiesis and is important for mobilizing neutrophils into blood circulation. Due to the hematopoietic properties of G-CSF, it has been widely used to clinically treat chemotherapy-induced neutropenia. However, G-CSF can promote tumors by inhibiting innate and adaptive immunity and enhancing angiogenesis and neoplastic growth. Most G-CSF-producing tumors are associated with a poor prognosis. This indicates that G-CSF promotes cancer progression. Thus, identifying regulatory molecules involved in tumor-derived G-CSF expression may provide therapeutic targets for cancer treatment. This study identified considerable G-CSF expression in malignant breast, lung and oral cancer cells. However, G-CSF expression was barely detectable in non-invasive cell lines. Expression of G-CSF mRNA and protein increased during exposure to tumor necrosis factor-α (TNF-α). Treatment with U0126 (a mitogen-activated protein kinase inhibitor) drastically reduced basal levels of G-CSF and TNF-α-induced G-CSF in aggressive cancer cells. This study also showed that knockdown of extracellular signal-regulated kinase (ERK) 2 by shRNA was necessary and sufficient to eliminate the expression of tumor-derived G-CSF. This did not apply to ERK1. Therefore, ERK2 (but not ERK1) is responsible for the transcriptional regulation of tumor-derived G-CSF. The results indicate the pharmaceutical value of specific ERK2 inhibitors in treating patients with G-CSF-producing tumors.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Breast Neoplasms; Butadienes; Carcinoma, Squamous Cell; Cell Line, Tumor; Enzyme Inhibitors; Female; Gene Expression Regulation, Neoplastic; Granulocyte Colony-Stimulating Factor; Humans; Lung Neoplasms; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase 1; Mouth Neoplasms; Neoplasm Invasiveness; Neoplasms; Nitriles; RNA Interference; RNA, Messenger; RNA, Small Interfering; Tumor Necrosis Factor-alpha

Kaempferol has been proposed as a potential drug for cancer chemoprevention and treatment because it is a natural polyphenol contained in plant-based foods. Recent studies have demonstrated that kaempferol protects against cardiovascular disease and cancer. Based on this finding, we investigated the mechanisms by which kaempferol produces the anti-metastatic effect in human tongue squamous cell carcinoma SCC4 cells.. In this study, we provided molecular evidence associated with the anti-metastatic effect of kaempferol by demonstrating a substantial suppression of SCC4 cell migration and invasion. This effect was associated with reduced expressions of MMP-2 and TIMP-2 mRNA and protein levels. Analysis of the transcriptional regulation indicated that kaempferol inhibited MMP-2 transcription by suppressing c-Jun activity. Kaempferol also produced an inhibitory effect on the phosphorylation of ERK1/2.. These findings provide new insights into the molecular mechanisms involved in the anti-metastatic effect of kaempferol, and are valuable in the prevention of oral cancer metastasis.

Topics: Butadienes; Cell Line, Tumor; Cell Movement; Cell Survival; DNA, Neoplasm; Down-Regulation; Extracellular Signal-Regulated MAP Kinases; Gene Expression Regulation, Neoplastic; Humans; Kaempferols; Matrix Metalloproteinase 2; Matrix Metalloproteinase Inhibitors; Mouth Neoplasms; Neoplasm Invasiveness; Nitriles; Phosphorylation; Protein Binding; RNA, Messenger; Signal Transduction; Tissue Inhibitor of Metalloproteinase-2; Transcription Factor AP-1; Transcription, Genetic

The emergence of radioresistance is a significant issue in the treatment of squamous cell carcinoma. We recently demonstrated that post-radiogenic extracellular signal-regulated kinase (ERK) signaling might decrease radiosensitivity in this cancer type. To further elucidate how tumor-organizing cell types respond to irradiation and ERK pathway inhibition, we analyzed one oral squamous cell carcinoma and one lung cancer cell line (HNSCCUM-02T, A549), fibroblasts (NIH3T3), primary normal and cancer-associated fibroblasts (CAFs) in vitro. Irradiated cells treated with mitogen-activated protein kinase (MAPK) inhibitor U0126 were screened for pERK levels. Post-radiogenic cellular responses were functionally analyzed by proliferation and colony assays. We found analogous pERK expression, proliferation and survival of tumor and normal fibroblast cells. CAFs did not show any response to treatment. We hypothesized that radiation and MAPK inhibition have no dose-limiting effect on tumor-surrounding normal tissue. As CAFs are considered to influence the radioresponse of the entire tumor, but are not affected by treatment themselves, potential CAF-mediated tumor protection should be considered in further studies.

Topics: Animals; Butadienes; Carcinoma, Non-Small-Cell Lung; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Cell Survival; Extracellular Signal-Regulated MAP Kinases; Fibroblasts; Humans; Lung Neoplasms; MAP Kinase Signaling System; Mice; Mouth Neoplasms; NIH 3T3 Cells; Nitriles; Protein Kinase Inhibitors; Radiation Dosage; Radiation Tolerance; Tumor Stem Cell Assay

Oral squamous cell carcinoma (OSCC) has a striking tendency to migrate and metastasize. Cysteine-rich 61 (Cyr61), from the CCN gene family, is a secreted and matrix-associated protein, which is involved in many cellular activities such as growth and differentiation. However, the effects of Cyr61 on human OSCC cells are largely unknown. In this study, we found that Cyr61 increased the migration and the expression of matrix metalloproteinases-3 (MMP)-3 in human OSCC cells. αvβ5 or α6β1 monoclonal antibody (mAb), focal adhesion kinase (FAK) inhibitor, and mitogen-activated protein kinase (MEK) inhibitors (PD98059 and U0126) inhibited the Cyr61-induced increase of the migration and MMP-3 up-regulation of OSCC cells. Cyr61 stimulation increased the phosphorylation of FAK, MEK, and extracellular signal-regulated kinase (ERK). In addition, NF-κB inhibitors suppressed the cell migration and MMP-3 expression enhanced by Cyr61. Moreover, Cyr61 increased NF-κB luciferase activity and binding of p65 to the NF-κB element on the MMP-3 promoter. Taken together, our results indicate that Cyr61 enhances the migration of OSCC cells by increasing MMP-3 expression through the αvβ3 or α6β1 integrin receptor, FAK, MEK, ERK, and NF-κB signal transduction pathway.

Topics: Antibodies, Monoclonal; Butadienes; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Movement; Cysteine-Rich Protein 61; Extracellular Signal-Regulated MAP Kinases; Flavonoids; Focal Adhesion Protein-Tyrosine Kinases; Humans; Integrin alpha6beta1; Matrix Metalloproteinase 3; Mitogen-Activated Protein Kinases; Mouth Neoplasms; NF-kappa B; Nitriles; Phosphorylation; Promoter Regions, Genetic; Receptors, Vitronectin; Transcription Factor RelA

Protein kinase C (PKC) zeta has been implicated as a mediator of epidermal growth factor (EGF) receptor (EGFR) signaling in certain cell types. Because EGFR is ubiquitously expressed in squamous cell carcinomas of the head and neck (SCCHN) and plays a key role in tumor progression, we determined whether PKCzeta is required for tumor cell proliferation and viability. Examination of total and phosphorylated PKCzeta expression in normal oral mucosa, dysplasia, and carcinoma as well as SCCHN tumor cell lines revealed a significant increase in activated PKCzeta expression from normal to malignant tissue. PKCzeta activity is required for EGF-induced extracellular signal-regulated kinase (ERK) activation in both normal human adult epidermal keratinocytes and five of seven SCCHN cell lines. SCCHN cells express constitutively activated EGFR family receptors, and inhibition of either EGFR or mitogen-activated protein kinase (MAPK) activity suppressed DNA synthesis. Consistent with this observation, inhibition of PKCzeta using either kinase-dead PKCzeta mutant or peptide inhibitor suppressed autocrine and EGF-induced DNA synthesis. Finally, PKCzeta inhibition enhanced the effects of both MAPK/ERK kinase (U0126) and broad spectrum PKC inhibitor (chelerythrine chloride) and decreased cell proliferation in SCCHN cell lines. The results indicate that (a) PKCzeta is associated with SCCHN progression, (b) PKCzeta mediates EGF-stimulated MAPK activation in keratinocytes and SCCHN cell lines, (c) PKCzeta mediates EGFR and MAPK-dependent proliferation in SCCHN cell lines; and (d) PKCzeta inhibitors function additively with other inhibitors that target similar or complementary signaling pathways.

Topics: Alkaloids; Amino Acid Sequence; Benzophenanthridines; Butadienes; Carcinoma, Squamous Cell; Cell Growth Processes; Cell Line, Tumor; Cell Transformation, Neoplastic; DNA, Neoplasm; Enzyme Activation; Epidermal Growth Factor; ErbB Receptors; Head and Neck Neoplasms; Humans; Keratinocytes; Mitogen-Activated Protein Kinases; Molecular Sequence Data; Mouth Mucosa; Mouth Neoplasms; Nitriles; Phenanthridines; Protein Kinase C; Protein Kinase Inhibitors

In the United States, oral cancer accounts for more deaths annually than cervical cancer, leukemias, or Hodgkin's lymphoma. Studies have shown that aberrations of chromosome 18q develop with tumor progression and are associated with significantly decreased survival in head and neck cancer patients. The G-protein-coupled receptor, galanin receptor 1 (GALR1), maps to this region of chromosome 18q. Although the role of GALR1 has been well characterized in neuronal cells, little is known regarding this receptor in non-neuronal cells. In this study, the expression, mitogenic function, and signaling mechanism of GALR1 are investigated in normal and malignant oral epithelial cells. mRNA expression was determined via reverse transcriptase-PCR. Protein quantification was done via immunoblot analysis and enzyme-linked immunosorbent assay. For functional and signaling studies, an inhibitory antibody was generated to the N-terminal ligand binding domain of GALR1. GALR1 protein and mRNA expression and GAL secretion were detected at variable levels in immortalized human oral keratinocytes and human oropharyngeal squamous cell carcinoma cell lines. Upon competitive inhibition of GALR1, proliferation was up-regulated in immortalized and malignant keratinocytes. Furthermore, studies with the inhibitory antibody and U0126, the MAPK inhibitor, show that GALR1 inhibits proliferation in immortalized and malignant keratinocytes by inactivating the MAPK pathway. GALR1s inhibitory effects on proliferation in epithelial cells raises the possibility that inactivation or disregulation of this receptor can lead to uncontrolled proliferation and neoplastic transformation.

Topics: Animals; Antibodies; Antineoplastic Agents; Binding, Competitive; Butadienes; Carcinoma, Squamous Cell; Cell Proliferation; Cell Transformation, Neoplastic; Cells, Cultured; CHO Cells; Chromosomes, Human, Pair 18; Cricetinae; Culture Media, Conditioned; Enzyme Activation; Enzyme Inhibitors; Enzyme-Linked Immunosorbent Assay; Galanin; Humans; Immunoblotting; Keratinocytes; Ligands; MAP Kinase Signaling System; Models, Biological; Mouth Neoplasms; Nitriles; Protein Binding; Protein Structure, Tertiary; Receptor, Galanin, Type 1; Receptor, Galanin, Type 2; Receptor, Galanin, Type 3; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Time Factors; Transfection; Up-Regulation