Wei-En Yang

Kaempferol reduces matrix metalloproteinase-2 expression by down-regulating ERK1/2 and the activator protein-1 signaling pathways in oral cancer cells.

Background 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. Methodology/Principal Findings 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. Conclusions 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.

The urokinase-type plasminogen activator (uPA) system as a biomarker and therapeutic target in human malignancies

ABSTRACT Introduction: The urokinase plasminogen activator (uPA) system, comprising the serine protease uPA, its cognate receptor, uPAR, and two endogenous inhibitors, plasminogen activator inhibitor-1 (PAI-1) and plasminogen activator inhibitor-2 (PAI-2), is a key player in the break-down of extracellular matrix (ECM) and basement membrane. Elevated expression of uPA and uPAR is observed in numerous cancer types and associated with poor prognosis. Areas covered: In addition to the aberrant expression during tumor development, the components of uPA system are functionally involved in various processes that are prerequisite for cancer progression. These processes include, but not limited to, ECM degradation, angiogenesis, cell proliferation, adhesion, migration and epithelial–mesenchymal transition. All of these findings implicate uPA system as a target for cancer treatment. Thus, therapeutic agents and approaches to targeting the constituents of uPA system, mainly at their expression level and biological activities, have been extensively used in antineoplastic investigations. Expert opinion: Because of promising results obtained from previous preclinical studies, several clinical trials aimed at inhibiting the expression or function of uPA/uPAR have been completed or are ongoing. In these trials, favorable outcomes in reducing metastatic spread and extending the lifespan of cancer patients have been reported, and no severe adverse events were observed.

Melatonin inhibits TPA-induced oral cancer cell migration by suppressing matrix metalloproteinase-9 activation through the histone acetylation.

Melatonin exerts antimetastatic effects on liver and breast cancer and also inhibits matrix metalloproteinase (MMP) activity. However, the detailed impacts and underlying mechanisms of melatonin on oral cancer cell metastasis are still unclear. This study showed that melatonin attenuated the 12-O-tetradecanoylphorbol-13-acetate-induced migration of oral cancer cell lines, HSC-3 and OECM-1. Zymography, quantitative real-time PCR, and Western blotting analyses revealed that melatonin lessened MMP-9 enzyme activity as well as the expression of MMP-9 mRNA and protein. Furthermore, melatonin suppressed the phosphorylation of the ERK1/2 signalling pathway, which dampened MMP-9 gene transcription by affecting the expression of transcriptional coactivators, such as CREB-binding protein (CREBBP) and E1A binding protein p300 (EP300), and decreasing histone acetylation in HSC-3 and OECM-1 cells. Examinations on clinical samples exhibited that MMP-9, CREBBP, and EP300 were significantly increased in oral cancer tissues. Moreover, the relative level of CREBBP was positively correlated with the expression of MMP-9 and EP300. In conclusion, we demonstrated that melatonin inhibits the motility of HSC-3 and OECM-1 cells in vitro through a molecular mechanism that involves attenuation of MMP-9 expression and activity mediated by decreased histone acetylation.

Pterostilbene suppresses oral cancer cell invasion by inhibiting MMP-2 expression

Objective: Polyphenol compounds, present in a wide variety of natural plants, exhibit antioxidant and free radical scavenging ability and induce apoptosis in various cancer cells. However, the effect of pterostilbene on oral cancer cell metastasis has not been clarified. Research design and methods: The present study aimed to examine the anti-metastatic properties of pterostilbene in human oral squamous cell carcinoma (SCC)-9 cells. Results: In this study, pterostilbene treatment significantly inhibited migration/invasion capacities of SCC-9 cells in vitro. The results of zymography and western blotting revealed that the activities and protein levels of the MMP-2 and urokinase-type plasminogen activator (u-PA) was inhibited by pterostilbene. Western blot analysis also showed that pterostilbene inhibits the phosphorylation of Akt, extracellular signal-regulated kinase 1/2 and p38. Determinations of the mRNA levels, real-time polymerase chain reaction and promoter assays were conducted to evaluate the inhibitory effects of pterostilbene on MMP-2 and u-PA expression in SCC-9 cells. Such inhibitory effects were associated with the upregulation of tissue inhibitor of metalloproteinase-2, plasminogen activator inhibitor-1 and the downregulation of the transcription factors of NF-κB, SP-1 and CREB signaling pathways. Conclusions: Pterostilbene may have potential use as a chemopreventive agent against oral cancer metastasis.

Exome Sequencing of Oral Squamous Cell Carcinoma Reveals Molecular Subgroups and Novel Therapeutic Opportunities

Oral squamous cell carcinoma (OSCC), an epithelial malignancy affecting a variety of subsites in the oral cavity, is prevalent in Asia. The survival rate of OSCC patients has not improved over the past decades due to its heterogeneous etiology, genetic aberrations, and treatment outcomes. Improvement in therapeutic strategies and tailored treatment options is an unmet need. To unveil the mutational spectrum, whole-exome sequencing of 120 OSCC from male individuals in Taiwan was conducted. Analyzing the contributions of the five mutational signatures extracted from the dataset of somatic variations identified four groups of tumors that were significantly associated with demographic and clinical features. In addition, known (TP53, FAT1, EPHA2, CDKN2A, NOTCH1, CASP8, HRAS, RASA1, and PIK3CA) and novel (CHUK and ELAVL1) genes that were significantly and frequently mutated in OSCC were discovered. Further analyses of gene alteration status with clinical parameters revealed that the tumors of the tongue were enriched with copy-number alterations in several gene clusters containing CCND1 and MAP4K2. Through defining the catalog of targetable genomic alterations, 58% of the tumors were found to carry at least one aberrant event potentially targeted by US Food and Drug Administration (FDA)-approved agents. Strikingly, if targeting the p53-cell cycle pathway (TP53 and CCND1) by the drugs studied in phase I-III clinical trials, those possibly actionable tumors are predominantly located in the tongue, suggesting a better prediction of sensitivity to current targeted therapies. Our work revealed molecular OSCC subgroups that reflect etiological and prognostic correlation as well as defined the landscape of major altered events in the coding regions of OSCC genomes. These findings provide clues for the design of clinical trials for targeted therapies and stratification of OSCC patients with differential therapeutic efficacy.

Dehydroandrographolide inhibits oral cancer cell migration and invasion through NF-κB-, AP-1-, and SP-1-modulated matrix metalloproteinase-2 inhibition

Graphical abstract Figure. No Caption available. Background and purpose: Oral cancer is a type of head and neck cancer that is characterized by cancerous tissue growth in the oral cavity. Andrographolide and dehydroandrographolide (DA) are the two principal components of Andrographis paniculata (Burm.f.) Nees and are the main contributors to its therapeutic properties. However, the pharmacological activities of DA remain unclear. Experimental approach: In this study, we used wound closure assay and Boyden chamber assay to determine the effects of DA on oral cancer cell migration and invasion. Key results: DA treatment significantly inhibited the migration and invasion abilities of SCC9 cells in vitro. Gelatin zymography and Western blotting results revealed that DA inhibited MMP‐2 activity and reduced its protein levels. DA inhibited the phosphorylation of ERK1/2, p38, and JNK 1/2 in SCC9 cells. According to the mRNA levels detected using real‐time PCR, DA inhibited MMP‐2 expression in SCC9 cells. This inhibitory effect was associated with the upregulation of the TIMP‐2 and downregulation of NF‐&kgr;B, AP‐1, and SP‐1 expression. In addition, DA suppressed carcinoma‐associated epithelial–mesenchymal transition in SCC9 cells. Finally, DA administration effectively suppressed MMP‐2 expression and tumor metastases in the oral carcinoma xenograft mouse model in vivo. Conclusions & implications: DA inhibits the invasion of human oral cancer cells and is a potential chemopreventive agent against oral cancer metastasis.

Cathepsin B Expression and the Correlation with Clinical Aspects of Oral Squamous Cell Carcinoma

Background Cathepsin B (CTSB), a member of the cathepsin family, is a cysteine protease that is widely distributed in the lysosomes of cells in various tissues. It is overexpressed in several human cancers and may be related to tumorigenesis. The main purpose of this study was to analyze CTSB expression in oral squamous cell carcinoma (OSCC) and its correlation with patient prognosis. Methodology/Principal Findings Tissue microarrays were used to detect CTSB expression in 280 patients and to examine the association between CTSB expression and clinicopathological parameters. In addition, the metastatic effects of the CTSB knockdown on two oral cancer cell lines were investigated by transwell migration assay. Cytoplasmic CTSB expression was detected in 34.6% (97/280) of patients. CTSB expression was correlated with positive lymph node metastasis (p = 0.007) and higher tumor grade (p = 0.008) but not with tumor size and distant metastasis. In addition, multivariate analysis using a Cox proportional hazards model revealed a higher hazard ratio, demonstrating that CTSB expression was an independent unfavorable prognostic factor in buccal mucosa carcinoma patients. Furthermore, the Kaplan–Meier curve revealed that buccal mucosa OSCC patients with positive CTSB expression had significantly shorter overall survival. Moreover, treatment with the CTSB siRNA exerted an inhibitory effect on migration in OC2 and CAL27 oral cancer cells. Conclusions We conclude that CTSB expression may be useful for determining OSCC prognosis, particularly for patients with lymph node metastasis, and may function as a biomarker of the survival of OSCC patients in Taiwan.

Andrographolide suppresses the migratory ability of human glioblastoma multiforme cells by targeting ERK1/2-mediated matrix metalloproteinase-2 expression

Glioblastoma multiforme (GBM) can be a fatal tumor because of difficulties in treating the related metastasis. Andrographolide is the bioactive component of the Andrographis paniculata. Andrographolide possesses the anti-inflammatory activity and inhibits the growth of various cancers; however, its effect on GBM cancer motility remains largely unknown. In this study, we examined the antimetastatic properties of andrographolide in human GBM cells. Our results revealed that andrographolide inhibited the invasion and migration abilities of GBM8401 and U251 cells. Furthermore, andrographolide inhibited matrix metalloproteinase (MMP)-2 activity and expression. Real-time PCR and promoter activity assays indicated that andrographolide inhibited MMP-2 expression at the transcriptional level. Such inhibitory effects were associated with the suppression of CREB DNA-binding activity and CREB expression. Mechanistically, andrographolide inhibited the cell motility of GBM8401 cells through the extracellular-regulated kinase (ERK) 1/2 pathway, and the blocking of the ERK 1/2 pathway could reverse MMP-2-mediated cell motility. In conclusion, CREB is a crucial target of andrographolide for suppressing MMP-2-mediated cell motility in GBM cells. Therefore, a combination of andrographolide and an ERK inhibitor might be a good strategy for preventing GBM metastasis.

High Level of Plasma EGFL6 Is Associated with Clinicopathological Characteristics in Patients with Oral Squamous Cell Carcinoma

EGF-like domain 6 (EGFL6), a member of the epidermal growth factor (EGF) repeat protein superfamily, is a secreted protein that promotes endothelial cell migration and angiogenesis. The current study investigated the association between the clinicopathological characteristics and plasma level of EGFL6 in patients with oral squamous cell carcinoma (OSCC). We measured the plasma EGFL6 levels of 392 OSCC patients by using a commercial enzyme-linked immunosorbent assay. We also analyzed EGFL6 mRNA levels of 328 OSCC patients from The Cancer Genome Atlas (TCGA) dataset. The results showed that plasma EGFL6 levels were significantly higher in patients with OSCC than in healthy controls (p < 0.001). Similar results were observed for the TCGA bioinformatics database. Moreover, plasma EGFL6 levels were significantly higher in the patients with advanced T status (p = 0.002), distant metastasis (p = 0.001), and higher TNM stage (p=0.033). In conclusion, our results suggest that plasma level of EGFL6 may be useful to assess disease progression, and especially advanced T status and higher TNM stage in patients with OSCC.

Plasma Levels of Endothelial Cell-Specific Molecule-1 as a Potential Biomarker of Oral Cancer Progression

In Taiwan, oral cancer is the fourth most common cancer and the most common malignancy with a poor prognosis. Endothelial cell-specific molecule-1 (ESM-1) is secreted by vascular endothelial cells in the liver, lungs, kidneys, and gastrointestinal tract. ESM-1 expression is associated with tumor prognosis, metastasis, and angiogenesis in many cancers. However, few studies have examined the association of plasma ESM-1 levels with oral squamous cell carcinoma (OSCC) progression. We measured the plasma ESM-1 levels of 438 male OSCC patients through a commercial enzyme-linked immunosorbent assay. The Cancer Genome Atlas (TCGA) dataset was also used to analyze the ESM-1 levels in 328 OSCC patients and 33 normal tissues. Our results revealed that the plasma levels of ESM-1 in OSCC patients were significantly associated with the tumor (T) status but not with the lymph node status, metastasis, and cell differentiation. TCGA bioinformatics database analysis revealed that ESM-1 expression was significantly higher in OSCC patients than in normal individuals (p < 0.05). In addition, the examination revealed similar results for the ESM-1 expression levels and pathological stage in OSCC. In conclusion, plasma ESM-1 is a novel biomarker for predicting the T status in OSCC patients.