Oral Cancer Metastasis Research Articles

CCL18-NIR1 promotes oral cancer cell growth and metastasis by activating the JAK2/STAT3 signaling pathway

BackgroundChemokine (C-C motif) ligand 18 (CCL18) affects the malignant progression of varying cancers by activating chemokine receptors. Our previous work has shown that CCL18 promotes hyperplasia and invasiveness of oral cancer cells; however, the cognate receptors of CCL18 involved in the pathogenesis of oral squamous cell carcinoma (OSCC) have not yet been identified. This study aimed to investigate the molecular mechanisms which underlie promotive effects of CCL18 on OSCC progression by binding to functional receptors.MethodsThe expression of CCL18 receptor-NIR1 in OSCC was determined by conducting western blot, immunofluorescence, and immunocytochemistry assays. Chi square test was applied to analyze the relationship between expression levels of NIR1 and clinicopathological variables. Recombinant CCL18 (rCCL18), receptor siRNA and JAK specific inhibitor (AG490) were used in experiments investigating the effects of the CCL18-NIR1 axis on growth of cancer cells (i.e., proliferation, and metastasis), epithelial-mesenchymal transition (EMT) and the activation of the JAK2/STAT3 signaling pathway.ResultsNIR1 as functional receptor of CCL18 in OSCC, was found to be significantly upregulated in OSCC and positively related to the TNM stage of OSCC patients. rCCL18 induced the phenotypical alterations in oral cancer cells including cell growth, metastasis and EMT. The JAK2/STAT3 signaling pathway was confirmed to be a downstream pathway mediating the effects of CCL18 in OSCC. AG490 and knockdown of NIR1 could block the effects of rCCL18-induced OSCC.ConclusionCCL18 can promote the progression of OSCC by binding NIR1, and the CCL18-NIR1 axis can activate JAK2/STAT3 signaling pathway. The identification of the mechanisms underlying CCL18-mediated promotion of OSCC progression could highlight potential therapeutic targets for treating oral cancer.

Effects of DSPP and MMP20 Silencing on Adhesion, Metastasis, Angiogenesis, and Epithelial-Mesenchymal Transition Proteins in Oral Squamous Cell Carcinoma Cells.

Recent reports highlight the potential tumorigenic role of Dentin Sialophosphoprotein (DSPP) and its cognate partner Matrix Metalloproteinase 20 (MMP-20) in Oral Squamous Cell Carcinomas (OSCCs). However, the function/mechanism of these roles is yet to be fully established. The present study aimed to investigate the effects of DSPP and MMP20 silencing on specific proteins involved in oral cancer cell adhesion, angiogenesis, metastasis, and epithelial-mesenchymal transition (EMT). Stable lines of DSPP/MMP20 silenced OSCC cell line (OSC2), previously established via lentiviral-mediated shRNA transduction, were analyzed for the effects of DSPP, MMP20, and combined DSPP–MMP20 silencing on MMP2, MMP9, integrins αvβ3 and αvβ6, VEGF, Kallikerin- 4,-5,-8,-10, E-cadherin, N-cadherin, Vimentin, met, src, snail, and Twist by Western blot. Results show a significant decrease (p < 0.05) in the expression of MMP2, MMP9, integrin αvβ3, αvβ6, VEGF, Kallikerins -4, -5, -8, -10, N-cadherin, vimentin met, src, snail and twist following DSPP and MMP20 silencing, individually and in combination. On the other hand, the expression of E-cadherin was found to be significantly increased (p < 0.05). These results suggest that the tumorigenic effect of DSPP and MMP20 on OSC2 cells is mediated via the upregulation of the genes involved in invasion, metastasis, angiogenesis, and epithelial-mesenchymal transition (EMT).

Analyzing the factors that influence occult metastasis in oral tongue cancer.

ObjectivesWe accessed the various clinico-histopathological factors, and their association with occult metastasis (OM) in oral tongue squamous cell carcinoma (OTSCC).Materials and MethodsOne hundred-nine patients with OTSCC were divided into the elective neck dissection (END) group and the watchful waiting (WW) group. Age, sex, T-stage, depth of invasion and differentiation were evaluated to determine the correlation between clinico-histopathological factors and OM. For immunohistochemical analysis, paraffin-embedded blocks of 41 OTSCC specimens were examined with antibodies (VEGF-c, c-Met, and ROR1).ResultsThe group with tumor thickness of oral tongue cancer ≥3 mm had higher incidence of OM than those with a thickness of <3 mm. The depth of invasion was statistically correlated with OM (P=0.022). Immunohistochemical analysis showed that high expression of VEGF-c (P=0.043), c-Met (P=0.009), and ROR-1 (P=0.003) were statistically correlated with OM.ConclusionThe analysis of these clinico-histopathological and immunohistochemical factors can help to determine neck dissection in clinically negative (cN0) patients.

NDRG1 deficiency is associated with regional metastasis in oral cancer by inducing epithelial-mesenchymal transition.

Regional metastasis is the single most important prognostic factor in oral squamous cell carcinoma (OSCC). Abnormal expression of N-myc downstream-regulated genes (NDRGs) has been identified to occur in several tumor types and to predict poor prognosis. In OSCC, the clinical significance of deregulated NDRG expression has not been fully established. In this study, NDRG1 relevance was assessed at gene and protein levels in 100 OSCC patients followed up by at least 10 years. Survival outcome was analyzed using a multivariable analysis. Tumor progression and metastasis was investigated in preclinical model using oral cancer cell lines (HSC3 and SCC25) treated with epidermal growth factor (EGF) and orthotopic mouse model of metastatic murine OSCC (AT84). We identified NDRG1 expression levels to be significantly lower in patients with metastatic tumors compared with patients with local disease only (P = 0.001). NDRG1 expression was associated with MMP-2, -9, -10 (P = 0.022, P = 0.002, P = 0.042, respectively) and BCL2 (P = 0.035). NDRG1 lower expression was able to predict recurrence and metastasis (log-rank test, P = 0.001). In multivariable analysis, the expression of NDRG1 was an independent prognostic factor (Cox regression, P = 0.013). In invasive OSCC cells, NDRG1 expression is diminished in response to EGF and this was associated with a potent induction of epithelial-mesenchymal transition phenotype. This result was further confirmed in an orthotopic OSCC mouse model. Together, this data support that NDRG1 downregulation is a potential predictor of metastasis and approaches aimed at NDRG1 signaling rescue can serve as potential therapeutic strategy to prevent oral cancer progression to metastasis.

Silencing of FOXA2 decreases E-cadherin expression and is associated with lymph node metastasis in oral cancer.

FOXA2 gene methylation links to the progression of cancers, but has not been documented in oral cancer. Herein, we explore the role of FOXA2 in the migration of oral cancer cells. Methylation-specific PCR was applied for gene methylation. Wound healing and transwell experiments were tested for cell migration. FOXA2 expression in oral cancer tissues was addressed by immunohistochemistry, followed by statistical analysis of its association with clinical manifestations and patient survival. FOXA2 bound to the promoter of CDH1 and enhanced the expression of its gene product E-cadherin, and decreased the cancer cell migration activity. High FOXA2 expression in oral cancer tissues was associated with high E-cadherin expression, decreased lymph node metastasis, and increased patient survival. FOXA2-E-cadherin link is involved in regulation of oral cancer cell metastasis and provides a new insight for the tumor suppressor activity of FOXA2 in oral cancer.

"Aberrant sialylation plays a significant role in oral squamous cell carcinoma progression".

Aberrant glycosylation, mainly sialylation and fucosylation, is recently considered as a major hallmark of cancer. Aberrant sialylation has long been associated with various neoplastic diseases. However, role of aberrant sialylation in oral cancer is still in its infancy. The present study aimed to examine mRNA expressions of α-2, 3, α-2, 6 sialyltransferase (ST) families and sialidase in 160 human oral cancer tissues. mRNA expression of ST3GAL1, ST3GAL2, ST3GAL3, ST3GAL4, ST3GAL6, ST6GAL1, and neuraminidase 3 (NEU3) was analyzed by RT-qPCR in 80 paired malignant and adjacent normal tissues from oral cancer patients. The results indicated significant (P≤.05) down-regulation of various STs (ST3GAL1, ST3GAL2, ST3GAL3, ST3GAL4, ST3GAL6, and ST6GAL1) and sialidases (NEU3) in malignant tissues as compared to adjacent normal tissues. Higher mRNA levels of ST3GAL2 and ST3GAL3 were significantly associated with advanced stage of the disease, lymph node involvement, and perineural invasion, which denote their role in progression and metastasis of oral cancer. Present study also revealed altered sialylation patterns according to anatomical site of the disease and tobacco habit. The study demonstrated significant role of elevated mRNA levels of ST3GAL2 and ST3GAL3 in disease progression and metastasis of oral carcinoma.

Vascular Endothelial Growth Factor-C as a Predictive Marker for Lymph Node Metastasis in Oral Cancer

Vascular Endothelial Growth Factor-C as a Predictive Marker for Lymph Node Metastasis in Oral Cancer

Development of clinico-histopathological predictive model for the assessment of metastatic risk of oral squamous cell carcinoma.

CONTEXT:Oral cancer metastasis is the leading cause of death globally. The decision-making on the mode of surgical treatment in clinically negative lymph nodes is challenging.AIM:The aim of this study was to develop a predictive model using clinical and histopathologic parameters that may help in the assessment of the metastatic risk of oral squamous cell carcinoma (OSCC).SETTINGS AND DESIGN:Clinical data of histopathologically confirmed primary OSCC from 2014 to 2017 were retrieved from the archives. Histopathological parameters for metastasis that were considered for evaluation in the study were tumor buds, cytoplasmic pseudofragments, tumor grade, depth of invasion, invasive tumor front (ITF) pattern, and lymphovascular invasion (LVI).METHODS:Hematoxylin and eosin and pan-cytokeratin immunostained sections of metastatic and nonmetastatic OSCC were assessed for histopathological features and correlated with clinical parameters.STATISTICAL ANALYSIS USED:SPSS software (Statistical Package for Social Sciences for Windows, Version 22.0 (2013) (IBM Corp., Armonk, NY, USA)) was used for the statistical analysis. Pearson's Chi-square test was done to assess the grades of histopathological and clinical parameters between the study groups. Univariate analysis was performed to develop a clinicopathologic predictive model.RESULTS:The clinicopathologic model signifies that OSCC with clinical Stage IV, high grades of tumor buds and cytoplasmic pseudofragments, Type V ITF pattern, positive LVI, deeply invasive tumors, and poorly differentiated grades of OSCC have a high risk of developing nodal metastasis. These parameters may be used as early predictors for metastasis of OSCC both in incisional and excisional biopsy specimens.CONCLUSIONS:The proposed predictive model is simple, cost-effective, and user-friendly for the early assessment of nodal metastatic risk in clinically negative lymph nodes.

Computational Analysis of Oral Cancer Gene Expression Profile and Identification of MiRNAs and their Regulatory Hub Genes

Oral cancer is one of the major cancers causing death worldwide. Micro RNAs (miRNAs) are small RNA molecules, each capable of coding several genes. In oral cancer, many miRNAs were proven to be expressed in higher level in tumor samples when compared to normal. Iin this work, the miRNAs commonly expressed In oral cancer patients were analysed. The miRNAs hsa-miR-6514-3p’, ‘hsa-miR-34b-3p’, ‘hsa-miR-142-3p’, ‘hsa-miR-146b-5p’, ‘hsa-miR-451b’, ‘hsa-miR-519e’ and ‘hsa-miR-3591-3p were up-regulated in oral cancer patients. They coded for the genes AMN1, CUL1 and CDC14. The expression of these genes were related to oral cancer growth, progression and metastasis. Hence identifying drugs that could target these genes could help in reducing the oral cancer mortality by improving progression of patients.

A Review on Salivary Proteomics for Oral Cancer Screening.

Oral cancer has emerged as a global health problem due to its relatively high incidence and mortality. Human saliva as a diagnostic fluid can offer an easy, inexpensive, safe and non-invasive approach for disease detection. Direct contact between saliva and oral cancer lesions make detection of salivary biomarkers for oral cancer especially attractive. Proteins are important molecules involved in pathological processes of oral cancer growth, apoptosis and metastasis. Proteins such as hormones, antibodies, enzymes and cytokines in saliva secreted by oral cancer cells or by host cells not only provide comprehensive pathological information of oral cancer but also are considered potential targets for non-invasive screening of oral cancer. This article provides a review of potential salivary proteomic biomarkers in oral cancer screening.

Epithelial-mesenchymal transition in oral squamous cell carcinoma: An insight into molecular mechanisms and clinical implications.

Epithelial–mesenchymal transition (EMT) is an important event in embryonic development, fibrosis and cancer invasion. During cancer progression, the activation of EMT permits cancer cells to acquire migratory, invasive and stem-like properties. Despite recent advances in treatment, there is no improvement in the 5-year overall survival rate of oral squamous cell carcinoma (OSCC). Local recurrence and lymph node metastasis are considered to be mainly responsible for the low survival rate in OSCC. EMT plays a major role in local recurrence and lymph node metastasis of oral cancer. This review article addresses the clinical implications of EMT in OSCC and explains the molecular mechanisms of EMT, highlighting the cadherin switching and signaling pathways involved.

Management of retropharyngeal lymph node metastasis in oral cancer

ObjectivesRetropharyngeal lymph node (RPLN) metastasis is extremely rare, and prognosis is significantly poor in oral cancer. We retrospectively examined the management of RPLN metastases in oral cancer. Materials and methodsA total of 1247 patients with oral cancer were treated at our department from January 2002 and December 2016. Among these patients, 374 (30%) had histologically positive lymph node metastases. Of these, 15 patients (1.2%) were diagnosed with RPLN metastases. We evaluated the diagnostic period, size, recurrence pattern, laterality, treatment, and therapeutic outcomes. The Kaplan–Meier method was used to determine overall survival (OS) among the RPLN metastasis group, cervical lymph node (CLN) metastases group, and treatment methods group for RPLN metastases. ResultsOne patient had RPLN involvement at the initial treatment, and RPLN involvement in other patients was found subsequently. The mean duration in confirming RPLN metastases was 228 days (range, 50–867 days). Surgical therapy was performed in 5 patients, chemoradiotherapy in 7 patients, and best supported care (BSC) in 3 patients. The cumulative 5-year OS rate for the RPLN metastasis group (n = 15) was 38.1%, compared with the rate of 71.3% for the CLN group (n = 359). Regarding the therapeutic approach for RPLN metastases, OS rates were 80.0% (n = 5) in the surgical therapy group, 28.6% (n = 7) in the chemoradiotherapy group, and 0% (n = 3) in the BSC group. ConclusionEarly detection and surgical treatment of RPLN metastases are associated with increased survival rate in oral cancer.

Loss of TIMP3 by promoter methylation of Sp1 binding site promotes oral cancer metastasis

The tissue inhibitor of metalloproteinase-3 (TIMP3) is the only member of the TIMP family that binds to the extracellular matrix and suppresses cancer cell growth, angiogenesis, migration, and invasion. However, whether the abnormal expression and promoter methylation of TIMP3 facilitates oral cancer metastasis remain unclear. In this study, the DNA methylation levels of TIMP3 CpG islands were assessed through pyrosequencing. Artificial modulation of TIMP3 was performed to explore the role of TIMP3 in tumor metastasis in vitro and in vivo. Our results showed that the suppression of TIMP3 transcription by DNA methylation involves the inhibition of the binding of the transcription factor Sp1 to the TIMP3 promoter as well as the upregulation of DNMT1 and DNMT3B. Functional analyses revealed that TIMP3 overexpression reduced migration and invasion abilities in oral cancer cells and inhibited lymph node metastasis in vivo. Moreover, TIMP3 regulated epithelial–mesenchymal transition by increasing the expression of the epithelial markers and reducing the expression of the mesenchymal markers. In conclusion, our findings suggested that the suppression of TIMP3 by DNA methylation contributes to oral cancer metastasis.

UNC13C Suppress Tumor Progression via Inhibiting EMT Pathway and Improves Survival in Oral Squamous Cell Carcinoma.

Potential function of UNC13C in variety of cancers including, oral squamous cell carcinoma (OSCC) remains obscure. In the present study, immunohistochemical staining in tissue microarrays containing 268 OSCC samples showed that UNC13C protein levels were inversely correlated with AJCC Stage III and IV (P = 0.002) and death (P = 0.0134). Patients with lower UNC13C expression had a significantly shorter survival (P = 0.0231) than those with higher UNC13C expression. We also identified decreased overall UNC13C expression in oral cancer cell lines. In addition, our functional analysis of UNC13C shows that overexpression of UNC13C inhibited migration and invasion capacities of SCC-9 and SAS cells compared with the empty plasmid transfected cells. Further experiments suggested that transcription factors (Slug, Snail, Twist, and ZEB1) and mesenchymal marker (Vimentin) were down regulated and Tight Junction Protein (Claudin1) was up regulated after UNC13C overexpression in SCC9 and SAS cells. The novel role of UNC13C is revealed for the first time in OSCC. In summary, these results suggest that UNC13C as a novel tumor suppressor and an essential regulator of EMT signaling pathway during OSCC progression, and thus it could be used as a target for preventing oral cancer metastasis.

Abstract 4542: The use of saliva proteins as biomarkers to predict the risk of lymph node metastasis in oral cancer

Abstract Background. The most common oral cancer in the world is squamous cell carcinoma (OSCC), accounting for more than 90% of all cases of cancer in the oral cavity. Thus, the research on molecular markers associated with the development and progress of human diseases has been the subject of intense research. The findings that saliva has molecular profiles indicating systemic diseases urge the study of non-invasive diagnosis using saliva as source of potential diagnosis, prognosis and predictive based on proteomics. Methods. 204 proteotypic peptides were selected previously based on DDA data from our own studies or retrieved from the SRMAtlas. Heavy labeled synthetic peptides were synthetized and SRM method was developed using Skyline v3.6. Saliva samples were collected from patients with lymph node metastasis (n=26) and without lymph node metastasis (n=14). Saliva proteins were digested with trypsin. Samples were randomized in R environment and analyzed in a triple-quadrupole mass spectrometer (Xevo TQ-XS, Waters). A Peptide Retention Time Calibration Mixture was spiked into the samples. Data comparison between groups was performed using Wilcoxon Mann Whitney test in R environment. Results. In the SRM method, we monitored 68 proteins and 24 of them were found decreased in patients with lymph node metastasis in comparison with patients without lymph node metastasis. The data analysis showed that at least one protein has, by itself, a higher relative risk in the development of lymph node metastasis in patients with OSCC. Two other panel of proteins presented the same relative risk described before. Conclusions. This study indicates a panel of potential OSCC marker proteins, which can contribute to the prognostic evaluation, the patient's risk profile and the possibility of recurrence, and guide therapeutic intervention strategies. Note: This abstract was not presented at the meeting. Citation Format: Tatiane De Rossi, Daniela Campos Granato, Ana Carolina Ribeiro, César Rivera, Henry Heberle, Guilherme Pimentel Telles, Carolina Moretto Carnielli, Thais Bianca Brandão, Alan Roger Santos-Silva, Márcio Ajudarte Lopes, Adriana Franco Paes Leme. The use of saliva proteins as biomarkers to predict the risk of lymph node metastasis in oral cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4542.

Abstract 176: Tetraspanins in oral squamous cell carcinoma

Abstract Objectives: To (1) investigate the expression levels of several tetraspanins in oral cancer cells and tissues; (2) characterize the subpopulation of oral cancer cells with elevated CD82; and (3) investigate roles of the tetraspanins in oral cancer migration, invasion, and metastasis. Methods: The protein expression levels of tetraspanins CD82(KAI1), CD9, CD81(TAPA), and their associate protein EWI-2(IGSF8) were quantified in normal human gingival epithelial cells (SG) and oral cancer cells (CAL27 and SCC-25 cells) using western blotting and immunofluorescence staining and imaging. CAL27 CD82 knockout cells (CD82KO) were created by CRISPR/CAS-9, sorted by Fluorescent Activated Cell Sorting, and validated by western blotting. A wound healing assay was used to study the role of CD82 in oral cancer cell migration. CD82 perturbation of the CAL27 genome and proteome were evaluated using Microarray (Affymetrix) and TRAQ/TMT Based Differential Protein Expression Analysis (Thermo, mass spectrometer). Results: So far, we have found (1) CD82 is highly expressed in CAL27 cancer cells, but its expression is low in SG and SCC-25 cells; (2) CD82 is highly expressed in human tongue cancer tissues; (3) CD9 is highly expressed in CAL27 cells; (4) The expression levels of CD81 and IGSF8 are comparable in the three cancer cell lines; (5) CAL27 cancer cells migrate faster than normal SG cells; (6) Knockout of CD82 significantly decreases the migration rate of CAL27 cells, suggesting that CD82 promotes migration of these cancer cells. Conclusions: CD82 has varied expression in different oral cancer cell lines. Its expression is very high in CAL27 cancer cells. Knockout of CD82 in CAL27 cells significantly inhibits migration of these cells. Our study suggests that CD82 might be used as a biomarker for a subpopulation of oral cancer cells and that CD82 could be a target for therapeutic interventions. Acknowledgements: Supported in part by the 2017 UTHSC CORNET Award. Supported in part by the UTHSC College of Dentistry Alumni Endowment Fund and the Tennessee Dental Association Foundation. Citation Format: Kiran K. Reddi, Kenneth M. Anderson, Franklin Garcia-Godoy, Yanhui H. Zhang. Tetraspanins in oral squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 176.

Abstract 2774: Pain signals oral cavity cancer metastasis

Abstract Metastasis to the cervical (neck) lymph nodes is the primary determinant of survival for patients diagnosed with oral cavity cancer. Imaging (MRI, PET, CT) and clinical examination lack sensitivity to accurately detect cervical metastasis. Therefore most clinically node negative patients receive surgery to remove the cervical lymph nodes (elective neck dissection) at the time of surgical tumor removal. Half of these patients do not benefit from this additional surgery, highlighting the need for improved preoperative assessment in predicting metastatic risk. Oral cancer patients suffer severe chronic and mechanically-induced pain at the site of the cancer. We asked whether patient reported pain measured prior to surgery by a validated instrument, the University of California San Francisco Oral Cancer Pain Questionnaire (UCSFOCPQ), was an indicator of risk for lymph node metastasis. Seventy-two oral cancer patients were consented and enrolled, patients rated their pain using the UCSFOCPQ. Clinical and pathological characteristics of the patient cohorts were collected from pathology reports and medical records. Inclusion criteria included diagnosis of an oral squamous cell carcinoma, planned curative resection of the cancer and completion of the UCSFOCPQ within six weeks of surgery. Exclusion criteria included prior chemo- or radiation therapy for cancer, failure to complete or understand the UCSFOCPQ and less than one year post surgery follow-up. Sixty-six patients met the inclusion/exclusion criteria (35 node negative and 31 node positive). Patients with metastasis reported higher pain scores prior to surgery. Low pain score and depth of invasion each predicted low metastatic risk with high sensitivity and negative predictive values. Amongst patients who were clinically staged N0 by current standard of care imaging and physical exam prior to surgery, low pain scores correctly identified patients determined by pathology to be N0. Conclusions: Low pain scores assessed prior to surgery could identify patients at low risk for metastases who would not benefit from neck dissection. Pain score might be added to the standard of care preoperative assessments and decision making processes for determining whether to recommend an elective neck dissection. Citation Format: Aditi Bhattacharya, Malvin N. Janal, Hyesung Kim, Susanna Wang, Angie K. Wu, Mari Hagiwara, Alexander R. Kerr, Brian L. Schmidt, Donna G. Albertson. Pain signals oral cavity cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2774.

Pinosylvin reduced migration and invasion of oral cancer carcinoma by regulating matrix metalloproteinase-2 expression and extracellular signal-regulated kinase pathway

BackgroundPinosylvin possesses several biological properties, including anti-inflammatory, antitumor, and antioxidant characteristics. However, the effects of pinosylvin on the migration and invasion of human oral cancer cells and the underlying mechanisms remain unclear. Hypothesis/purposeIn this research, we investigated the outcome of different concentrations of pinosylvin (0–80 μM) on the metastatic and invasive abilities of SAS, SCC-9, and HSC-3 cells. Methods and resultsWestern blotting assay and Gelatin zymography assay indicated that pinosylvin inhibited the enzymatic activity of matrix metalloproteinase-2 (MMP-2) and reduced its protein level but increased the expression of tissue inhibitor of metalloproteinase-2 (TIMP-2). Additionally, the wound healing assay and Transwell method showed that pinosylvin reduced the migration of SAS, SCC-9 and HSC-3 oral cancer cells. Besides, pinosylvin decreased the phosphorylation of ERK1/2 protein experssion in both SAS and SCC-9 cells. ConclusionThese results indicate that pinosylvin is a potential anticancer agent for preventing oral cancer metastasis.

Nicotine promotes cervical metastasis of oral cancer by regulating peroxiredoxin 1 and epithelial-mesenchymal transition in mice.

BackgroundTobacco is a major risk factor for oral squamous cell carcinoma (OSCC). However, the role of nicotine in OSCC is not completely understood.Materials and methodsTo analyze the mechanisms of nicotine-induced cervical metastasis, we investigated whether nicotine induced invasion, migration, and epithelial–mesenchymal transition (EMT) via regulating peroxiredoxin 1 (Prx1) in CAL 27 cells. In addition, we established a mouse model to confirm the roles of nicotine in regulating Ets1/Prx1/EMT signaling in OSCC metastasis.ResultsWe showed that nicotine induced CAL 27 cell invasion, migration, EMT, and Prx1 and Ets1 expression. Prx1 knockdown inhibited cell invasion, migration, and EMT. Ets1 silencing downregulated Prx1 expression and EMT. Prx1 and Ets1 were shown to interact in CAL 27 cells treated with nicotine, and nicotine could significantly upregulate the binding of the transcription factor Ets1 to the Prx1 gene promoter region. Additionally, an in vivo study showed that nicotine induced tumor metastasis and EMT. Prx1 knockdown inhibited cervical metastasis rates and EMT progression. No significant differences in metastasis rates and EMT-related marker expression levels were observed between vehicle- and nicotine-treated mice.ConclusionThe results indicate that nicotine promotes cervical lymph node metastasis through regulating Ets1/Prx1/EMT signaling during OSCC pathogenesis; consequently, Prx1 may represent a potential target for the prevention and treatment of OSCC.

Lymph node metastasis in oral cancer is strongly associated with chromosomal instability and DNA repair defects.

Oral squamous cell carcinoma (OSCC) is highly prevalent in south and southeast Asia. Many (30-50%) OSCC patients develop lymph node metastasis (LNM), which is the most important prognostic factor in OSCC. To identify genomic correlates of LNM, we compared exome sequences and copy number variation data of blood and tumor DNA from highly contrasting subgroups of patients to reduce false inferences-(i) patients with LNM and (ii) patients with late stage disease but without LNM. We found that LNM is associated with (i) specific hotspot somatic mutations in TP53 and CASP8; (ii) rare nonsilent germline mutations in BRCA2 and FAT1; (iii) mutations in mito-G2/M and nonhomologous end joining (NHEJ) pathways; (iv) recurrent deletion of genes for DNA repair by homologous recombination; and (v) chromosomal instability. LN+ patients with NHEJ pathway mutations have longer disease-free survival. Five genomic features have a high predictive value of LNM.