Age and risk of recurrence in oral tongue squamous cell carcinoma: Systematic review

Management of a carcinoma in situ of the tongue margin, using a Nd:YAG laser, cross-linked hyaluronic acid (xHyA) gel and a porcine pericardium resorbable membrane: a case report

BACKGROUND

Oral tongue squamous cell carcinoma is the most prevalent cancer of the oral cavity. To date, the mainstay management for carcinoma in situ of the oral cavity is the surgical radical removal of the neoplastic tis-sue. This paper describes a new approach in the management of an in situ carcinoma of the tongue margin, treated surgically by the use of Nd:YAG laser, the application of cross-liked hyaluronic acid (xHyA) gel and the placement of a resorbable porcine pericardium membrane (PPM).

CASE PRESENTATION

The case involves a 49-years old male patient with no history of smoking and alcohol use, who presented a non-homogeneous leukoplakia of the right tongue border. The biopsy revealed high-grade lichenoid dysplasia, corresponding to severe epithelial dysplasia or carcinoma in situ (Tis), characterized by full-thickness dysplasia without stromal invasion.

CONCLUSIONS

The case shows that the combined use of Neodimium laser surgery, xHyA gel and PPM is a viable option for promoting soft tissue regeneration in the oral cavity, enabling excellent clinical results in terms of healing medium-sized surgical defects. In addition, compared with other options for the reconstruction of surgical defects of the tongue, the clinical use of the association between these two materials has several biological advantages due to the absence of donor sites and high patient tolerability.

MRI in Oral Tongue Squamous Cell Carcinoma: A Radiomic Approach in the Local Recurrence Evaluation

(1) Background: Oral tongue squamous cell carcinoma (OTSCC) is a prevalent malignancy with high loco-regional recurrence. Advanced imaging biomarkers are critical for stratifying patients at a high risk of recurrence. This study aimed to develop MRI-based radiomic models to predict loco-regional recurrence in OTSCC patients undergoing surgery. (2) Methods: We retrospectively selected 92 patients with OTSCC who underwent MRI, followed by surgery and cervical lymphadenectomy. A total of 31 patients suffered from a loco-regional recurrence. Radiomic features were extracted from preoperative post-contrast high-resolution MRI and integrated with clinical and pathological data to develop predictive models, including radiomic-only and combined radiomic-clinical approaches, trained and validated with stratified data splitting. (3) Results: Textural features, such as those derived from the Gray-Level Size-Zone Matrix, Gray-Level Dependence Matrix, and Gray-Level Run-Length Matrix, showed significant associations with recurrence. The radiomic-only model achieved an accuracy of 0.79 (95% confidence interval: 0.69, 0.87) and 0.74 (95% CI: 0.54, 0.89) in the training and validation set, respectively. Combined radiomic and clinical models, incorporating features like the pathological depth of invasion and lymph node status, provided comparable diagnostic performances. (4) Conclusions: MRI-based radiomic models demonstrated the potential for predicting loco-regional recurrence, highlighting their increasingly important role in advancing precision oncology for OTSCC.

LncRNA CCAT1 knockdown suppresses tongue squamous cell carcinoma progression by inhibiting the ubiquitination of PHLPP2

Tongue squamous cell carcinoma (TSCC) is prevailing malignancy in the oral and maxillofacial region, characterized by its high frequency. LncRNA CCAT1 can promote tumorigenesis and progression in many cancers. Here, we investigated the regulatory mechanism by which CCAT1 influences growth and metastasis of TSCC. Levels of CCAT1, WTAP, TRIM46, PHLPP2, AKT, p-AKT, and Ki67 in TSCC tissues and cells were assessed utilizing qRT-PCR, Western blot and IHC. Cell proliferation, migration, and invasion were evaluated utilizing CCK8, colony formation, wound healing and transwell assays. Subcellular localization of CCAT1 was detected utilizing FISH assay. m6A level of CCAT1 was assessed using MeRIP. RNA immunoprecipitation (RIP), Co-immunoprecipitation (Co-IP) and RNA pull down elucidated binding relationship between molecules. Nude mouse tumorigenesis experiments were used to verify the TSCC regulatory function of CCAT1 in vivo. Metastatic pulmonary nodules were observed utilizing hematoxylin and eosin (HE) staining. CCAT1 silencing repressed TSCC cell proliferation, migration and invasion. Expression of CCAT1 was enhanced through N6-methyladenosine (m6A) modification of its RNA, facilitated by WTAP. Moreover, IGF2BP1 up-regulated CCAT1 expression by stabilizing its RNA transcript. CCAT1 bond to PHLPP2, inducing its ubiquitination and activating AKT signaling. CCAT1 mediated the ubiquitination and degradation of PHLPP2 by TRIM46, thereby promoting TSCC growth and metastasis. CCAT1/TRIM46/PHLPP2 axis regulated proliferation and invasion of TSCC cells, implying that CCAT1 would be a novel therapeutic target for TSCC patients.

TRAIP enhances progression of tongue squamous cell carcinoma through EMT and Wnt/β-catenin signaling by interacting with DDX39A

BACKGROUND

Tongue squamous cell carcinoma (TSCC) is one of the most common malignant tumors with high mortality and poor prognosis. Its incidence rate is increasing gradually. Tumor necrosis factor receptor-associated factor interacting protein (TRAIP), as a factor related to several tumors, reveals that its gene expression is different between normal tissue and primary tumor of head and neck squamous cell carcinoma using bioinformatics analysis.

METHOD

In our study, TCGA database, immunohistochemistry, proliferation assay, colony formation, wound healing assay, Transwell, cell cycle analysis and tumor xenografts model were used to determine the expression and functions of TRAIP in TSCC.

RESULT

We found that TRAIP may promote the proliferation, migration and invasion of TSCC. Furthermore, the results of bioinformatics analysis, mass spectrometry and co-immunoprecipitation suggested that DDX39A may be a TRAIP interacting protein. DDX39A has been proven to be an oncogene in several tumors, which may have an important effect on cell proliferation and metastasis in multiple tumors. In addition, the high expression of DDX39A implies the poor prognosis of patients. Our study demonstrated that TRAIP probably interact with DDX39A to regulate cell progression through epithelial-mesenchymal transition and Wnt/β-catenin pathway. In addition, we show that the necessary domain of DDX39A for the interaction between DDX39A and TRAIP region.

CONCLUSION

These results indicate that TRAIP is important in occurrence and development of TSCC and is expected to become the new promising therapeutic target.

Survival among treated tongue cancer patients: a single-center experience

OBJECTIVE

To describe overall survival (OS) and disease-free survival (DFS) in a cohort of tongue cancer patients, together with the corresponding demographic, tumor and surgical characteristics.

METHODS

A retrospective study was made of 205 consecutive patients with primary tongue cancer subjected to surgery and adjuvant therapy according to the stage of the disease, in Hospital Clínico Universitario Virgen de la Arrixaca (HUVA) (Murcia, Spain) during the period 2000-2020. Survival was evaluated based on the Kaplan-Meier method, and the existence of significant differences between the different study variables was analyzed using the log-rank test. Cox regression analysis was performed for the identification of risk factors.

RESULTS

In relation to overall survival, 72.6% of the patients survived for a mean time of 14.43 years [standard error (SE) = 0.74; 95% CI: 12.98-15.87], with a cumulative survival rate of 49.8 ± 3%. Survival was reduced by the presence of tumor adjacent to resection margins [hazard ratio (HR) 2.20; 95% CI 1.09-4.43] (p = 0.028) and infiltrated resection margins (HR 3.86, 95% CI 1.56-9.57) (p = 0.004). Lymphadenectomy in turn increased survival (HR 0.15; 95% CI 0.06-0.42) (p < 0.001). In relation to disease-free survival, 55.3% of the patients suffered no relapse over a mean period of 9.91 years (SE = 0.66; 95% CI: 8.61-11.2), with a cumulative survival rate of 26.6% ± 8.4%.

CONCLUSIONS

In tongue cancer patients, overall and specific survival were reduced in the presence of infiltrated resection margins. Lymphadenectomy in turn improved survival compared with patients in which this procedure was not carried out.

Foregoing elective neck dissection for elderly patients with oral cavity squamous cell carcinoma

OBJECTIVE

Elective neck dissection (END) improves outcomes among clinically node-negative patients with oral cavity squamous cell carcinoma (OCSCC). However, END is of questionable value, considering the potentially higher comorbidities and operative risks in elderly patients.

METHODS

A retrospective review of all patients older than 65 years of age who were treated for OCSCC at a tertiary care centre between 2005 and 2020 was conducted.

RESULTS

Fifty-three patients underwent primary tumour resection alone, and 71 had simultaneous END. Most primary tumours were located on the mobile tongue. The patients who did not undergo END had a higher mean age (81.2 vs. 75.1 years, P < 0.00001), significantly shorter surgeries, and shorter hospitalizations. Occult cervical metastases were found in 24% of the patients who underwent END. The two groups showed no significant differences in overall survival or recurrence rates. Similar results were shown in a subpopulation analysis of patients older than 75 years.

CONCLUSION

Foregoing END in elderly patients with no clinical evidence of neck metastases did not result in lower survival rates or higher recurrence rates.

Naringenin-induced Oral Cancer Cell Apoptosis Via ROS-mediated Bid and Bcl-xl Signaling Pathway

BACKGROUND

Oral cancer is a malignant tumor with a high impact and poor prognosis. Naringenin, a flavonoid found in citrus fruits and its anti-inflammatory and antioxidant properties offer potential therapeutic benefits. However, limited studies have been conducted on the impact of naringenin on human tongue carcinoma CAL-27 cells. This study aims to elucidate the correlation between naringenin and tongue cancer, thereby identifying a potential therapeutic candidate for drug intervention against tongue cancer.

METHODS

The effect of naringenin on the apoptosis of CAL-27 cells and its mechanism were studied by cell counting kit-8, mitochondrial membrane potential assay with JC-1, Annexin V-- FITC apoptosis detection, cell cycle, and apoptosis analysis, Reactive Oxygen Species assay and Western blot.

RESULTS

The results showed that naringenin significantly induced apoptosis in CAL-27 cells in a dose-dependent manner. Mechanistically, naringenin-induced apoptosis was mediated through the upregulation of Bid and downregulation of Bcl-xl, which led to increased generation of ROS.

CONCLUSION

The findings suggested that naringenin may represent a promising candidate for the treatment of oral cancer by inducing apoptotic cell death via modulation of the Bid and Bcl-xl signaling pathways.

Prediction of 5-year overall survival of tongue cancer based machine learning

OBJECTIVE

We aimed to develop a 5-year overall survival prediction model for patients with oral tongue squamous cell carcinoma based on machine learning methods.

SUBJECTS AND METHODS

The data were obtained from electronic medical records of 224 OTSCC patients at the PLA General Hospital. A five-year overall survival prediction model was constructed using logistic regression, Support Vector Machines, Decision Tree, Random Forest, Extreme Gradient Boosting, and Light Gradient Boosting Machine. Model performance was evaluated according to the area under the curve (AUC) of the receiver operating characteristic curve. The output of the optimal model was explained using the Python package (SHapley Additive exPlanations, SHAP).

RESULTS

After passing through the grid search and secondary modeling, the Light Gradient Boosting Machine was the best prediction model (AUC = 0.860). As explained by SHapley Additive exPlanations, N-stage, age, systemic inflammation response index, positive lymph nodes, plasma fibrinogen, lymphocyte-to-monocyte ratio, neutrophil percentage, and T-stage could perform a 5-year overall survival prediction for OTSCC. The 5-year survival rate was 42%.

CONCLUSION

The Light Gradient Boosting Machine prediction model predicted 5-year overall survival in OTSCC patients, and this predictive tool has potential prognostic implications for patients with OTSCC.

A nomogram for predicting overall survival of patients with squamous cell carcinoma of the floor of the mouth: a population-based study

BACKGROUND

Floor of mouth squamous cell carcinoma (SCCFOM) is a rare but aggressive malignancy with 5-year overall survival (OS) rates below 40% in published studies. However, the clinicopathological predictors of the prognosis of SCCFOM remain undefined. We aimed to establish a model to predict the survival outcomes of SCCFOM.

METHODS

We searched the Surveillance, Epidemiology, and End Results (SEER) database for patients diagnosed with SCCFOM between 2000 and 2017. Data on patient demographics, treatment modalities, and survival outcomes were retrieved. Risk factors for OS were evaluated by survival and Cox regression analyses. A nomogram for OS was developed based on the multivariate model and split the patients into high- and low-risk cohorts based on cutoff values.

RESULTS

Overall, 2014 SCCFOM patients were included in this population-based study. Multivariate Cox regression showed that age, married status, grade, American Joint Committee on Cancer stage, radiotherapy, chemotherapy, and surgery were significant risk factors for survival. A nomogram was established using the regression model. The C-indices, areas under the receiver operating characteristic curves, and calibration plots demonstrated the reliable performance of the nomogram. Patients assigned to the high-risk group had a significantly lower survival rate.

CONCLUSIONS

The nomogram predicting survival outcomes of SCCFOM patients based on clinical information showed good discriminative ability and prognostic accuracy. Our nomogram could be used to predict the survival probabilities for SCCFOM patients at different timepoints.

The role of radiomics in tongue cancer: A new tool for prognosis prediction

BACKGROUND

Radiomics represents an emerging field of precision-medicine. Its application in head and neck is still at the beginning.

METHODS

Retrospective study about magnetic resonance imaging (MRI) based radiomics in oral tongue squamous cell carcinoma (OTSCC) surgically treated (2010-2019; 79 patients). All preoperative MRIs include different sequences (T1, T2, DWI, ADC). Tumor volume was manually segmented and exported to radiomic-software, to perform feature extraction. Statistically significant variables were included in multivariable analysis and related to survival endpoints. Predictive models were elaborated (clinical, radiomic, clinical-radiomic models) and compared using C-index.

RESULTS

In almost all clinical-radiomic models radiomic-score maintained statistical significance. In all cases C-index was higher in clinical-radiomic models than in clinical ones. ADC provided the best fit to the models (C-index 0.98, 0.86, 0.84 in loco-regional recurrence, cause-specific mortality, overall survival, respectively).

CONCLUSION

MRI-based radiomics in OTSCC represents a promising noninvasive method of precision medicine, improving prognosis prediction before surgery.

Prognosis of the Keratinizing Squamous Cell Carcinoma of the Tongue Based on Surveillance, Epidemiology, and End Results Database

BACKGROUND

The objective of this study is to determine the prognostic factors of keratinizing squamous cell carcinoma of the tongue (KTSCC) and to establish a prognostic nomogram of KTSCC to assist clinical diagnosis and treatment.

METHODS

This study identified 3874 patients with KTSCC from the Surveillance, Epidemiology, and End Results (SEER) database, and these patients were randomly divided into the training (70%, (n = 2711) and validation (30%, n = 1163) cohorts. Cox regression was then used to filter variables. Nomograms were then constructed based on meaningful variables. Finally, the concordance index (C-index), net reclassification index (NRI), integrated discrimination improvement (IDI), calibration charts, and decision-curve analysis (DCA), were used to evaluate the discrimination, accuracy and effectiveness of the model.

RESULTS

A nomogram model was established for predicting the 3-, 5-, and 8-year overall survival (OS) probabilities of patients with KTSCC. The model indicated that age, radiotherapy sequence, SEER stage, marital status, tumor size, American Joint Committee on Cancer (AJCC) stage, radiotherapy status, race, lymph node dissection status, and sex were factors influencing the OS of patients with KTSCC. Verified by C-index, NRI, IDI, calibration curve, and DCA curve, our model has better discrimination, calibration, accuracy and net benefit compared to the AJCC system.

CONCLUSIONS

This study identified the factors that affect the survival of KTSCC patients and established a prognostic nomogram that can help clinicians predict the 3-, 5-, and 8-year survival rates of KTSCC patients.

A Novel Tongue Squamous Cell Carcinoma Cell Line Escapes from Immune Recognition due to Genetic Alterations in HLA Class I Complex

Immune checkpoint inhibitors (ICI) have made progress in the field of anticancer treatment, but a certain number of PD-L1 negative OSCC patients still have limited benefits from ICI immuno-therapy because of primary immune evasion due to immunodeficiency. However, in existing human OSCC cell lines, cell models that can be used to study immunodeficiency have not been reported. The objective of this study was to establish a PD-L1 negative OSCC cell line, profile whether the presence of mutated genes is associated with immune deficiency, and explore its influence on the immune recognition of CD8⁺ T cells in vitro. Here, we established a novel tongue SCC cell line (WU-TSC-1), which escapes from immune recognition by antigen presentation defects. This cell line was from a female patient who lacked typical causative factors. The expression of PD-L1 was negative in the WU-TSC-1 primary tumor, transplanted tumor, cultured cells and lipopolysaccharide stimulation. Whole exome sequencing (WES) revealed that WU-TSC-1 harbored missense mutations, loss of copy number and structural variations in human leukocyte antigen (HLA) class I/II genes. The tumor mutation burden (TMB) score was high at 292.28. In addition, loss of heterozygosity at beta-2-microglobulin (B2M)-a component of all HLA class I complex allotypes-was detected. Compared with the commonly used OSCC cell lines, genetic alterations in HLA class I and B2M impeded the proteins' translation and inhibited the activation and killing effect of CD8⁺ T cells. In all, the WU-TSC-1 cell line is characterized by genetic variations and functional defects of the HLA class I complex, leading to escape from recognition by CD8⁺ T cells.

Goal-Oriented Physiotherapy Protocol of a 55-Year Male With Squamous Cell Carcinoma of the Tongue: A Case Report

Although oral cancer is well-known, the occurrence rate of the disease varies greatly globally. Squamous cell carcinoma of the tongue, which frequently starts in the lateral tongue, is the most common kind of oral cancer. In this instance, a male patient was found to have squamous cell carcinoma of the tongue and had undergone surgery. Following any surgical treatment of the tongue, discomfort, septicemia, difficulty eating, and speech issues are the most common oral consequences. His chief complaints were pain and difficulty in mouth opening. He also had the inability to move his tongue, which made talking and swallowing difficult. He had a history of chewing tobacco and smoking cigarettes for the past 15 years. A physiotherapy program was advised to the patient to reduce his symptoms, which included mouth-opening exercises, swallowing exercises, etc. The case's findings indicate that, when compared to the outcome measures, all objectives were met, and the patient improved in his activities of daily living.

Identification of ferroptosis-related genes as potential biomarkers of tongue squamous cell carcinoma using an integrated bioinformatics approach

Tongue squamous cell carcinoma (TSCC) is one of the deadliest cancers of the head and neck, but the role of the ferroptosis pathway in its development is still unknown. In this study we explored the pathogenetic mechanisms associated with ferroptosis in TSCC. We identified differentially expressed genes (DEGs) of TSCC patients and used gene ontology (GO), the Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene set enrichment analysis (GSEA) to annotate, visualize, and integrate these DEGs. Receiver operating characteristic curve (ROC) analysis was performed, and the STRING database was used to construct a protein–protein interaction network to evaluate the predictive value of ferroptosis‐related DEGs. A total of 219 DEGs were identified and GO, KEGG, and GSEA showed that extracellular matrix (ECM)‐receptor interaction and interleukin (IL)‐17 signaling pathways were substantially upregulated in TSCC. Univariate Cox analysis revealed that high expression of CA9, TNFAIP3, and NRAS were predictive of a worse outcome. We then constructed a prognostic model that predicted survival in the validation cohort at 1 year and 32 months. Finally, 60 cases of tongue carcinoma and normal tissues were collected, and immunohistochemistry was used to detect the expression of CA9. We found that CA9 was strongly expressed in tongue carcinoma tissues and absent in adjacent tissues. Overall, we found that ferroptosis‐related genes may affect TSCC prognosis through the ECM‐receptor interaction and IL‐17 signaling pathways. Additionally, immunohistochemistry confirmed that CA9 was highly expressed in tongue carcinoma tissues, and a model based on ferroptosis‐related genes showed a good ability to predict overall survival in TSCC.

Oral squamous cell carcinoma outcome in adolescent/young adult: Systematic review and meta-analysis

To perform a systematic review focusing on the prognosis of oral cavity squamous cell carcinoma (OSCC) in young patients (≤40 years old) compared to older (>40 years old). Four databases were used in our search strategy. First, all titles were systematically organized using the Covidence platform online. In the second phase, 118 full texts of potentially eligible studies were analyzed by reviewers independently and in pairs. Twelve studies were considered eligible for data extraction. The relapse was higher in the young than in controls (pooled relative risk (RR) = 1.31; 95% CI [1.10-1.56]). The 5-year disease-free survival (DFS) was worse in young group (pooled hazard ratio (HR) = 0.73; 95% CI [0.63-0.85]) but the 5-year overall survival (OS) estimate was similar between the groups (pooled HR = 0.84; 95% CI [0.70-1.00]). While the 5-year OS was similar between groups, the number of relapses and 5-year DFS were worse in patients with OSCC ≤40 years old.

Assessing the effect of human dental pulp mesenchymal stem cell secretome on human oral, breast, and melanoma cancer cell lines

Background

The secretome of the dental pulp mesenchymal stem cells (DPMSCS-S) have an array of regenerative potential and could aid in the rehabilitation of cancer patients post-therapeutic interventions, although caution is required as DPMSC-S have shown to augment prostate cancer cells. Thus, it is vital to assess if these pro-carcinogenic effects extend to other cancer types.

Objective

To assess if DPMSC-S has any pro-carcinogenic effect on oral cancer, breast cancer, and melanoma cell lines.

Materials and methods

Conditioned media obtained from the isolated and characterized DPMSC (DPMSC-CM) were profiled using bead-based multiplex assay. AW13515 (oral cancer), MDA-MB-231 (breast cancer), and A-375 (melanoma) cell lines were exposed to 20%, 50%, and 100% DPMSC-CM for 24, 48, and 72 h. DPMSC-CM effect on the cancer cell properties and secretome were assessed.

Results

DPMSC-CM augmented invasion, adhesion, multi-drug resistance, DNA repair, and mitochondrial repair in AW13516 through upregulation of growth factors Ang-2, EGF, M−CSF, PDGF-AA, PDGF-BB, pro-inflammatory cytokines TNF-α, IL-2, downregulation of anti-inflammatory cytokine TGF-β1, and pro-inflammatory cytokine IL-4. In MDA-MB-231, invasion, and multi-drug resistance were augmented through upregulation of growth factors EGF, EPO, G-CSF, HGF, M−CSF, PDGF-AA, and pro-inflammatory cytokine TNF-α, CXCL10, IL-12p70. EMT, invasion, migration, and adhesion were augmented in A-375 through upregulation of growth factors Ang-2, EGF, PDGF-BB, TGF-α, pro-inflammatory cytokines TNF-α, and IL-17A.

Conclusion

DPMSC-CM can augment the carcinogenic properties of oral cancer, breast cancer, and melanoma cells, further animal model studies are required to validate our in-vitro findings.

Novel Prediction Models for Patients With Oral Squamous Cell Carcinoma at Different Anatomical Sites

PURPOSE

The individualized prediction of oral cavity squamous cell carcinoma (OC-SCC) is essential and should be as comprehensive as possible. The aim of this study was to identify new risk factors and develop nomograms comparing all anatomic sites of the oral cavity.

MATERIALS AND METHODS

We performed a retrospective cohort study using the Surveillance, Epidemiology, and End Results (SEER) database. All patients with OC-SCC diagnosed from 2004 to 2015 were selected and divided into the training cohort and the validation cohort. Age, gender, race, marital status, primary site, tumor grade, American Joint Committee on Cancer (AJCC) stage, TNM stage, surgical treatment, radiotherapy and chemotherapy were identified as predictor variables. The overall survival (OS) and disease specific survival (DSS) were identified as outcome variables. Kaplan-Meier method with log-rank test, univariate and multivariate cox regression analysis were performed. Independent prognostic factors were used to develop 3- and 5-year nomograms. Hazard ratio (HR) and corresponding 95% confidence interval (CI) showed the influence of each factor on OS or DSS. Concordance indexes (C-indexes) and calibration curves verified the nomograms internally and externally.

RESULTS

A total of 12,346 patients were included. Marital status and chemotherapy were independent prognostic factors (P < .05). Tumors occurring on the cheek mucosa had the highest risk in OS (HR, 2.0, 95% CI, 1.7-2.3) and DSS (HR, 4.7, 95% CI, 3.6-6.0), while tumors occurring on the lip had the lowest risk in OS (HR, 1.0) and DSS (HR,1.0). The C-indexes for OS in the training and validation sets were 0.767 and 0.770, respectively, and for DSS were 0.800 and 0.799, respectively.

CONCLUSION

Marital status and chemotherapy independently affect OC-SCC patients' survival. The prognosis is least favorable for tumors occurring on the cheek mucosa and most favorable for tumors occurring on the lip.

AG-9, an Elastin-Derived Peptide, Increases In Vitro Oral Tongue Carcinoma Cell Invasion, through an Increase in MMP-2 Secretion and MT1-MMP Expression, in a RPSA-Dependent Manner

Oral tongue squamous cell carcinoma is one of the most prevalent head and neck cancers. During tumor progression, elastin fragments are released in the tumor microenvironment. Among them, we previously identified a nonapeptide, AG-9, that stimulates melanoma progression in vivo in a mouse melanoma model. In the present paper, we studied AG-9 effect on tongue squamous cell carcinoma invasive properties. We demonstrated that AG-9 stimulates cell invasion in vitro in a modified Boyen chamber model. It increases MMP-2 secretion, analyzed by zymography and MT1-MMP expression, studied by Western blot. The stimulatory effect was mediated through Ribosomal Protein SA (RPSA) receptor binding as demonstrated by SiRNA experiments. The green tea-derived polyphenol, (−)-epigallocatechin-3-gallate (EGCG), was previously shown to bind RPSA. Molecular docking experiments were performed to compare the preferred areas of interaction of AG-9 and EGCG with RPSA and suggested overlapping areas. This was confirmed by competition assays. EGCG abolished AG-9-induced invasion, MMP-2 secretion, and MT1-MMP expression.