Lymph Node Metastasis In Oral Squamous Cell Carcinoma Research Articles

The interaction of PRDX1 with Cofilin promotes oral squamous cell carcinoma metastasis.

Peroxiredoxin 1 (PRDX1) is an important member of the peroxiredoxin family (PRDX) and is upregulated in a variety of tumors. Previous studies have found that high PRDX1 expression is closely related to the metastasis of oral squamous cell carcinoma (OSCC), but the specific molecular mechanism is elusive. To elucidate the role of PRDX1 in the metastasis process of OSCC, we evaluated the expression of PRDX1 in OSCC clinical specimens and its impact on the prognosis of OSCC patients. Then, the effect of PRDX1 on OSCC metastasis and cytoskeletal reconstruction was explored in vitro and in nude mouse tongue cancer models, and the molecular mechanisms were also investigated. PRDX1 can directly interact with the actin-binding protein Cofilin, inhibiting the phosphorylation of its Ser3 site, accelerating the depolymerization and turnover of actin, promoting OSCC cell movement, and aggravating the invasion and metastasis of OSCC. In clinical samples and mouse tongue cancer models, PRDX1 also increased lymph node metastasis of OSCC and was negatively correlated with the phosphorylation of Cofilin; PRDX1 also reduced the overall survival rate of OSCC patients. In summary, our study identified that PRDX1 may be a potential therapeutic target to inhibit OSCC metastasis.

Abstract 3795: Possible role of miR-375-3p in cervical lymph node metastasis of oral squamous cell carcinoma

Abstract Latent cervical lymph node metastasis (LNM) is the most important prognostic factor in early oral squamous cell carcinoma (OSCC). However, no clinically useful predictors of LNM in early OSCC are available. In this study, we focused on the microRNAs (miRNAs) involved in the expression of numerous genes and explored those associated with latent cervical LNM in OSCC. Microarray analysis of miRNA expression showed that the expression levels of miR-375-3p were significantly reduced in primary OSCC tissues with latent cervical LNM. Subsequently, we quantified the expression of miR-375-3p by RT-qPCR and digital PCR. Similar to the results of miRNA microarray analysis, miR-375-3p was significantly downregulated in primary OSCC tissues with latent cervical LNM. The results of digital PCR showed a more significant difference than those of RT-qPCR. When the reference value for predicting latent cervical LNM was set to less than 57.85 copies based on the receiver operating characteristic curve, the sensitivity, specificity, accuracy, and area under the curve were 80%, 100%, 90%, and 0.942, respectively. Next, we examined the effects of miR-375-3p mimics on the growth and migration of four human OSCC cell lines (SAS-L1, HSC2, HSC3, and Ca9-22) that do not express miR-375-3p. When an miR-375-3p mimic was introduced into these cells, cell proliferation and migration were significantly suppressed. Total RNA was extracted from these cells reverse-transfected with miR-375-3p mimic for 48 hours. Microarray analysis and Ingenuity Pathway Analysis (IPA) miRNA target filter showed that miR-375-3p overexpression reduced the expression of 266 genes, of which 37 genes had the target sequences of miR-375-3p in their 3’-untranslated region. Among these target genes, CEPT1 and TIMM8A knockdown significantly inhibited the migration of all human OSCC cells, similar to miR-375-3p mimics. Furthermore, IPA core analysis revealed a decrease in expression of genes involved in the activation of PI3K-AKT pathways by miR-375-3p overexpression. These results indicated that downregulating miR-375-3p expression could promote cervical LNM by enhancing cell proliferation and migration in OSCC. We also found that CEPT1 and TIMM8A as novel target genes of miR-375-3p regulated the migration of human OSCC cells. The expression levels of miR-375-3p in primary OSCC tissues appear to be a useful biomarker for predicting latent cervical LNM. Citation Format: Masato Saika, Koh-ichi Nakashiro, Norihiko Tokuzen, Hiroyuki Shirai, Daisuke Uchida. Possible role of miR-375-3p in cervical lymph node metastasis of oral squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3795.

EMT Dynamics in Lymph Node Metastasis of Oral Squamous Cell Carcinoma.

Epithelial-mesenchymal transition (EMT) enables tumor cell invasion and metastasis. Many studies have demonstrated the critical role of EMT in lymph node metastasis in oral squamous cell carcinoma (OSCC). During EMT, epithelial cancer cells lose intercellular adhesion and apical-basal polarity and acquire mesenchymal properties such as motility and invasiveness. A significant feature of EMT is cadherin switching, involving the downregulation of E-cadherin and upregulation of N-cadherin. The TGF-β/SMAD pathway can also induce EMT. We aimed to evaluate EMT markers as predictors of lymph node metastasis in OSCC. We performed genetic profiling of 159 primary OSCCs from TCGA and analyzed the expression of EMT markers, including cadherin switch genes (CDH1, CDH2), and TGF-β/SMAD pathway genes. Samples were divided into advanced (stage III-IV) and early (stage I-II) stage groups. Differential expression analysis was performed, as well as an independent validation study containing fresh OSCC samples. TGF-β/SMAD pathway genes such as SMAD6 were upregulated in advanced stage tumors. N-cadherin and SNAIL2 were overexpressed in node-positive tumors. Keratins were downregulated in these groups. Our findings demonstrate that EMT marker expression correlates with lymph node metastasis in OSCC. Developing therapies targeting regulators such as N-cadherin may prevent metastasis and improve outcomes.

FD-Net: Feature Distillation Network for Oral Squamous Cell Carcinoma Lymph Node Segmentation in Hyperspectral Imagery.

Oral squamous cell carcinoma (OSCC) has the characteristics of early regional lymph node metastasis. OSCC patients often have poor prognoses and low survival rates due to cervical lymph metastases. Therefore, it is necessary to rely on a reasonable screening method to quickly judge the cervical lymph metastastic condition of OSCC patients and develop appropriate treatment plans. In this study, the widely used pathological sections with hematoxylin-eosin (H&E) staining are taken as the target, and combined with the advantages of hyperspectral imaging technology, a novel diagnostic method for identifying OSCC lymph node metastases is proposed. The method consists of a learning stage and a decision-making stage, focusing on cancer and non-cancer nuclei, gradually completing the lesions' segmentation from coarse to fine, and achieving high accuracy. In the learning stage, the proposed feature distillation-Net (FD-Net) network is developed to segment the cancerous and non-cancerous nuclei. In the decision-making stage, the segmentation results are post-processed, and the lesions are effectively distinguished based on the prior. Experimental results demonstrate that the proposed FD-Net is very competitive in the OSCC hyperspectral medical image segmentation task. The proposed FD-Net method performs best on the seven segmentation evaluation indicators: MIoU, OA, AA, SE, CSI, GDR, and DICE. Among these seven evaluation indicators, the proposed FD-Net method is 1.75%, 1.27%, 0.35%, 1.9%, 0.88%, 4.45%, and 1.98% higher than the DeepLab V3 method, which ranks second in performance, respectively. In addition, the proposed diagnosis method of OSCC lymph node metastasis can effectively assist pathologists in disease screening and reduce the workload of pathologists.

Fibromodulin overexpression drives oral squamous cell carcinoma via activating downstream EGFR signaling

Accumulating evidence has shown that fibromodulin (FMOD) plays a pivotal role in tumorigenesis and metastasis. However, the biological function of FMOD in oral squamous cell carcinoma (OSCC) remains largely unclear to date. In this study, we confirmed that FMOD was overexpressed and showed a significant association with malignant progression and lymph node metastasis in OSCC. Depletion of FMOD inhibited OSCC proliferation and metastasis invitro and invivo. RNA sequencing, western blotting, and rescue assays verified that FMOD exerted oncogenic roles in OSCC via activation of EGFR signaling. In addition, FMOD was proved to be a putative target gene of miR-338-3p. Taken together, FMOD overexpression due to the reduced level of miR-338-3p promotes OSCC by activating EGFR signaling. Our findings provide direct evidence that targeting FMOD could be a promising therapeutic strategy for OSCC patients.

Predicting cervical lymph node metastasis in OSCC based on computed tomography imaging genomics.

To investigate the correlation between computed tomography (CT) radiomic characteristics and key genes for cervical lymph node metastasis (LNM) in oral squamous cell carcinoma (OSCC). The region of interest was annotated at the edge of the primary tumor on enhanced CT images from 140 patients with OSCC and obtained radiomic features. Ribonucleic acid (RNA) sequencing was performed on pathological sections from 20 patients. the DESeq software package was used to compare differential gene expression between groups. Weighted gene co-expression network analysis was used to construct co-expressed gene modules, and the KEGG and GO databases were used for pathway enrichment analysis of key gene modules. Finally, Pearson correlation coefficients were calculated between key genes of enriched pathways and radiomic features. Four hundred and eighty radiomic features were extracted from enhanced CT images of 140 patients; seven of these correlated significantly with cervical LNM in OSCC (p < 0.01). A total of 3527 differentially expressed RNAs were screened from RNA sequencing data of 20 cases. original_glrlm_RunVariance showed significant positive correlation with most long noncoding RNAs. OSCC cervical LNM is related to the salivary hair bump signaling pathway and biological process. Original_glrlm_RunVariance correlated with LNM and most differentially expressed long noncoding RNAs.

Lymph node metastasis in oral squamous cell carcinoma: Where we are and where we are going

AbstractBackgroundOral cancer is a common malignant tumour in the head and neck region, with over 90% of cases being oral squamous cell carcinoma (OSCC). Lymph node metastasis (LNM) is a significant adverse prognostic factor in OSCC; however, the mechanism of LNM in OSCC remains unclear, while the strategies for managing cervical lymph nodes (CLNs) in OSCC continue to evolve. At present, neck dissection is necessary for the vast majority of OSCC patients, but complications of surgery can significantly impair patients’ postoperative quality of life. A recent clinical trial discovery indicates that immunotherapy can activate anti‐tumour T cells in nearby lymph nodes, leading to vibrant discussions among clinicians about the importance of preserving lymph nodes during surgical treatment.AimThis review aims to provide an overview of where we are: the current knowledge of OSCC LNM patterns and management strategies, and where we are going: prospects for clinical and basic research on the issue of OSCC LNM in the era of cancer immunotherapy.ResultWe summarize the general patterns and management strategies of OSCC LNM. The process of LNM in OSCC encompasses four stages: Preparation, Unleash, Migration, and Planting (‘PUMP’ principle). We propose adopting the ‘PRECISE’ model, an overall workflow that includes seven elements—prevention, radiology, preoperative evaluation, chemotherapy, immunotherapy, surgery, and postoperative evaluation—for neck management in OSCC, promoting personalized precision medicine augmented by neoadjuvant therapy. We further discussed recent advances in clinical and basic research on OSCC LNM and provided an outlook on future research directions.ConclusionOver the past two centuries, our understanding and management strategies of LNM in OSCC have evolved, seeking more precise and personalized approaches to reduce patient burden and enhance survival and quality of life. Further research should explore lymph nodes’ role in cancer immunotherapy and OSCC interactions, leading to better, less invasive treatments and improved outcomes.

Increased levels of PD1 and glycolysis in CD4+ T cells are positively associated with lymph node metastasis in OSCC

BackgroundCervical lymph node metastasis is one of the poorest prognostic factors in oral squamous cell carcinoma (OSCC). Activated immune cells generally have metabolic abnormalities in the tumour microenvironment. However, it is unknown whether abnormal glycolysis in T cells could facilitate metastatic lymph nodes in OSCC patients. The aim of this study was to investigate the effects of immune checkpoints in metastatic lymph nodes and determine the correlation between glycolysis and immune checkpoint expression in CD4+ T cells.MethodsFlow cytometry and immunofluorescence staining were used to analyse the differences in CD4+ PD1+ T cells between metastatic lymph nodes (LN+) and negative lymph nodes (LN−). RT‒PCR was performed to detail the expression of immune checkpoints and glycolysis-related enzymes in LN+ and LN−.ResultsThe frequency of CD4+ T cells decreased in LN+ patients (p = 0.0019). The PD1 expression of LN+ increased markedly compared to that of LN− (p = 0.0205). Similarly, the PD1 of CD4+ T cells in LN+ increased significantly compared to that of LN−. Additionally, glycolysis-related enzyme levels in CD4+ T cells from LN+ patients were dramatically higher than those in LN− patients. PD1 and Hk2 expression in CD4+ T cells was also increased in LN+ OSCC patients with prior surgical treatment compared to those without.ConclusionsThese findings suggest that lymph node metastasis and recurrence in OSCC are associated with increases in PD1 and glycolysis in CD4+ T cells; this response may serve as a potential regulator of OSCC progression.

REMARK scoring of biomarkers predicting lymph node metastasis in oral squamous cell carcinoma – A systematic review

Background: A universal and systematic protocol is essential for accurate reporting of biomarker studies. For unity in reporting biomarker studies, many guidelines were introduced, Recommendations for Tumor Marker Prognostic Studies (REMARK) being one of them. Aim: The purpose of this review is to evaluate the quality of published articles of biomarkers that predict metastasis in lymph nodes in oral squamous cell carcinoma (OSCC) by the use of the reporting recommendations for tumor marker prognostic (REMARK) guidelines. Methods: Comprehensive search was done in MEDLINE via PubMed and Cochrane from January 2015 to December 2019 to identify manuscripts evaluating biomarkers predicting lymph node metastasis in OSCC. The significance of the univariate and multivariate analysis was assessed for each manuscript, and P < 0.05 was considered statistically significant. Results: Thirty-six results were included for the qualitative synthesis. The mean REMARK score was 11.13 (range: 5.01–17.15). Biomarkers with the highest REMARK score were phospholipase C, cyclin D, CD44+/CD133+, and matrix metalloproteinase-9 (MMP-9). While biomarkers such as LGALS1, NCOA7, and TMOD1 were associated with high risk of bias, hence its use as a biomarker predicting lymph node metastasis is questionable. Conclusions: In our review of 36 manuscripts, manuscripts examining biomarkers evaluating lymph node metastasis in OSCC need an improvement in their reporting. Biomarkers such as phospholipase C, cyclin D, CD44+/CD133+, and MMP-9 can be used as a predictor of lymph node metastasis in OSCC.

GATA6 regulates expression of annexin A10 (ANXA10) associated with epithelial–mesenchymal transition of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) can disturb oral function and quality of life and is associated with poor survival, likely due to the development of cervical lymph node metastases. Epithelial-mesenchymal transition (EMT) is a process in which cells acquire molecular alterations that facilitate cell motility and invasion, and has been associated with tumor metastasis. EMT changes also play important roles in the induction of lymph node metastasis in OSCC. GATA6 is known as the earliest marker of the primitive endoderm lineages. GATA6 inhibits de-differentiation and EMT in human pancreatic ductal adenocarcinoma cells and promotes EMT. However, in OSCC, the expression and function of GATA6 in EMT and lymph node metastasis remains unclear. Therefore, this study aimed to clarify the targets of GATA6 in OSCC cells and whether the change in GATA6 expression affects EMT in OSCC cells, as well as the association between GATA6 and lymph node metastasis. The results showed that GATA6 knockdown OSCC cells promoted EMT and increased lymph node metastasis compared with control cells, whereas the overexpression of GATA6 inhibited the induction of EMT and reduced lymph node metastasis. In addition, annexin A10 (ANXA10) which is the largest type of Ca2+-regulated phospholipid-binding protein in eukaryotic cells was detected as a target gene for GATA6 and ANXA10 suppressed Vimentin expression in EMT in OSCC. Therefore, the GATA6/ANXA10 cascade may be a potential therapeutic approach for the treatment of lymph node metastases in OSCC patients.

Evaluation of Expression Of ADAM 10 as a Predictor of Lymph Node Metastasis in Oral Squamous Cell Carcinoma-An Immunohistochemical Study.

Lymph node metastasis (LNM) is a well-known prognostic factor in Oral Squamous Cell Carcinoma(OSCC). A biological marker that predicts the Lymph Node Metastasis (LNM) in OSCC cases is the need of the hour. A Disintegrin And Metalloproteinases (ADAMs), a family of proteins that exhibit a metalloproteinase domain play a pivotal role in the pathogenesis of tumor growth and metastasis. This study aims to evaluate whether ADAM 10 can be used as a predictor of lymph node metastasis in OSCC using immunohistochemistry. A total of 90 samples that were categorized into 3 groups were included in the present study. Group I consisted of 30 samples of the normal oral mucosa, and Group II consisted of 30 samples of OSCC without lymph node metastasis. Group III consisted of 30 samples of OSCC with lymph node metastasis. Esophageal Squamous Cell Carcinoma was used as external positive control. Immunohistochemical expression of ADAM10 in their corresponding stained sections was assessed and staining intensity was calculated. ADAM10 immunoreactivity was considered positive when located in cytoplasm or membrane or both. This method is similar to that used by Bamane et al. for OSCC cases. The mean value of the Staining Index score "AxB" was highest in Group III (7.90), followed by Group II (3.13) and least in Group I (0.27). These values were statistically significant. Considering the findings of a higher percentage of ADAM10 positive cells, higher staining intensity, and higher staining index, the overexpression of ADAM10 can be used as an independent marker for OSCC patients to predict the lymph node metastasis.

Perspective of nuclear fractal dimension in diagnosis and prognosis of oral squamous cell carcinoma.

Background:Owing to the restricted predictive value of conventional prognostic factors and the inconsistent treatment strategies, several oral squamous cell carcinoma (OSCC) patients are still over-treated or under-treated. In recent years, computer-assisted nuclear fractal dimension (nFD) has emerged as an objective approach to predict the outcome of OSCC.Objective:This study is an attempt to find out the differences in nFD values of epithelial cells of normal tissue, fibroepithelial hyperplasia, verrucous carcinoma, and OSCC. Further effort to evaluate the predictive potential of nFD of tumor cells for cervical lymph node metastasis (cLNM) was also assessed.Methodology:Formalin-fixed paraffin-embedded blocks of OSCC tissues of patients treated with neck dissection were collected. Photomicrographs of H-&E-stained sections were subjected to the image analysis by ImageJ and Python programming to calculate nFD. The association of categorical variables with nFD was studied using cross-tabulation procedure and the Fisher exact test. Receiver operating curve analysis was performed to find out cutoff value of nFD. A logistic regression model was developed to test the individual and combined predictive potential of grading and nFD for cLNM.Results:A significant difference between the mean nFD of healthy cells and malignant epithelial cells was observed (P = 0.01). nFD was not found to be an independent predictor of cLNM, although nFD and grading together demonstrated significant predictive potential (P = 0.004).Conclusion:nFD combined with grading can predict lymph node metastasis in OSCC. To the best of our knowledge, this is the first study of its kind.

Platelet CLEC2-Podoplanin Axis as a Promising Target for Oral Cancer Treatment.

Cancer tissues are not just simple masses of malignant cells, but rather complex and heterogeneous collections of cellular and even non-cellular components, such as endothelial cells, stromal cells, immune cells, and collagens, referred to as tumor microenvironment (TME). These multiple players in the TME develop dynamic interactions with each other, which determines the characteristics of the tumor. Platelets are the smallest cells in the bloodstream and primarily regulate blood coagulation and hemostasis. Notably, cancer patients often show thrombocytosis, a status of an increased platelet number in the bloodstream, as well as the platelet infiltration into the tumor stroma, which contributes to cancer promotion and progression. Thus, platelets function as one of the important stromal components in the TME, emerging as a promising chemotherapeutic target. However, the use of traditional antiplatelet agents, such as aspirin, has limitations mainly due to increased bleeding complications. This requires to implement new strategies to target platelets for anti-cancer effects. In oral squamous cell carcinoma (OSCC) patients, both high platelet counts and low tumor-stromal ratio (high stroma) are strongly correlated with increased metastasis and poor prognosis. OSCC tends to invade adjacent tissues and bones and spread to the lymph nodes for distant metastasis, which is a huge hurdle for OSCC treatment in spite of relatively easy access for visual examination of precancerous lesions in the oral cavity. Therefore, locoregional control of the primary tumor is crucial for OSCC treatment. Similar to thrombocytosis, higher expression of podoplanin (PDPN) has been suggested as a predictive marker for higher frequency of lymph node metastasis of OSCC. Cumulative evidence supports that platelets can directly interact with PDPN-expressing cancer cells via C-type lectin-like receptor 2 (CLEC2), contributing to cancer cell invasion and metastasis. Thus, the platelet CLEC2-PDPN axis could be a pinpoint target to inhibit interaction between platelets and OSCC, avoiding undesirable side effects. Here, we will review the role of platelets in cancer, particularly focusing on CLEC2-PDPN interaction, and will assess their potentials as therapeutic targets for OSCC treatment.

The neuropeptide calcitonin gene-related peptide links perineural invasion with lymph node metastasis in oral squamous cell carcinoma

ObjectiveAlthough perineural invasion (PNI) is well-known to be correlated with and able to predict lymph node metastasis (LNM) in oral squamous cell carcinoma (OSCC), the clinical and molecular correlation between PNI and LNM has not been elucidated, and preoperative biomarkers for LNM prediction in OSCC are urgently needed.Materials and methodsThe correlation between PNI and LNM was retrospectively evaluated using a cohort of 218 patients diagnosed with OSCC. Candidate neuropeptides were screened based on TCGA database and verified via immunohistochemistry and Western blot analyses. ELISA was used to detect calcitonin gene-related peptide (CGRP) in patient plasma. In vitro assays were used to explore the effects of CGRP on OSCC cells.ResultsOSCC patients with PNI had a higher incidence of LNM (69.86% vs. 26.2%, P < 0.0001, n = 218). CGRP expression was upregulated in the PNI niche and in metastatic lymph nodes, and was correlated with poor overall survival of OSCC patients. Preoperative plasma CGRP levels were higher in OSCC patients (n = 70) compared to healthy donors (n = 60) (48.59 vs. 14.58 pg/ml, P < 0.0001), and were correlated with LNM (P < 0.0001) and PNI (P = 0.0002). Preoperative plasma CGRP levels alone yielded an AUC value of 0.8088 to predict LNM, and CGRP levels combined with preoperative T stage reached an AUC value of 0.8590. CGRP promoted proliferation and migration abilities of OSCC cells, which could be antagonized by either pharmacological or genetic blockade of the CGRP receptor.ConclusionsThe neuropeptide CGRP links PNI and LNM in OSCC, and preoperative plasma CGRP levels can be used to predict LNM in OSCC.

Diagnostic value of magnetic resonance imaging in cervical lymph node metastasis of oral squamous cell carcinoma

The objective of this study was to investigate the correlation between magnetic resonance imaging (MRI) characteristics of cervical lymph nodes and the pathologically confirmed status of cervical lymph node metastasis (LNM) in oral squamous cell carcinoma (OSCC) and to provide imaging evaluation parameters for the clinical diagnosis of cervical lymph node status in OSCC. In a retrospective analysis, 79 patients who were first pathologically diagnosed with OSCC were included. The MRI-derived imaging parameters of the cervical lymph nodes were evaluated and the pathological status of lymph nodes in neck dissection specimens was reviewed. The relationship between the imaging parameters and cervical LNM was analyzed. The MRI-derived imaging parameters of 4419 lymph nodes were evaluated, and the pathological status of 2463 lymph nodes was reviewed. The MRI-derived shortest axial diameter (SAD) and unclear boundary of the cervical lymph node were significantly related to LNM. The cutoff value of SAD that enabled identification of LNM was 3.6 mm, and it was 4.2 and 4.1 mm for the prediction of overall survival and disease-specific survival, respectively. The MRI-derived parameters SAD and unclear boundary of the cervical lymph node correlated with LNM in OSCC. MRI-derived SAD larger than 3 mm warrants simultaneous neck dissection at initial surgery.

Cancer Stem Cell Markers, CD44 and ALDH1, for Assessment of Cancer Risk in OPMDs and Lymph Node Metastasis in Oral Squamous Cell Carcinoma.

Tumour heterogeneity in oral cancer is attributed to the presence of cancer stem cells (CSCs). CSCs are the most migratory and metastatic cellular subpopulation within tumours. Assessment of CSC markers as significant predictors of lymph node metastasis may prove valuable in the clinical setting. Furthermore, analysis of this panel of putative stem cell markers in oral dysplasia may additionally inform of the likelihood for oral potentially malignant disorders (OPMDs) to progress to oral squamous cell carcinoma (OSCC). The present study aims to assess the significance of CSC markers in the progression of OPMDs to OSCC and assessment of lymph node metastasis in OSCC. CD44 and ALDH1 were assessed immunohistochemically in 25 normal, 30 OPMDs, and 24 OSCCs. CD44 is a membranous marker and ALDH1 is a cytoplasmic marker. The immunohistochemical expression of these markers were compared between OPMDs with and without dysplasia, as well as between low-risk and high-risk dysplasias. Similarly, expression was compared between OSCC with and without lymph node metastasis and among grades of OSCC. Positive CD44 expression was seen in all normal mucosal tissues. The expression decreased from normal epithelium to OPMDs but increased in OSCC. CD44 expression was positive in 21 cases of OSCC (87.5%) and reduced from well-differentiated to poorly differentiated OSCC. CD44 staining index was higher in OSCC without lymph node metastasis (3.59) when compared with OSCC with lymph node metastasis (1.33). There was a statistically significant difference observed in the ALDH1 staining index among three groups (p < 0.05), with highest expression seen in OSCC. Within OPMDs, the ALDH1 staining index was statistically higher in OPMDs with dysplasia as compared to OPMDs without dysplasia. Furthermore, the expression was higher in OPMDs with high-risk dysplasia when compared with low-risk dysplasia, but this was not statistically significant (p = 0.82). In conclusion, The CD44 positive population possesses properties of CSCs in head and neck carcinoma, and continuous shedding could be found after CD44 down-regulation. The present study reports differences in ALDH1 expression between OPMDs with and without dysplasia, dysplastic and non-dysplastic epithelia, and low-risk and high-risk dysplasia. These findings may suggest ALDH1 as a specific marker for dysplasia. CD44 demonstrated a difference in staining index in OSCC without lymph node metastasis versus OSCC with lymph node metastasis. These findings may suggest CD44 as a marker for lymph node metastasis. Both proteins may play key roles in the tumorigenicity of CSCs in OPMDs and OSCC.

Fatty Acid Receptor CD36 Functions as a Surrogate Parameter for Lymph Node Metastasis in Oral Squamous Cell Carcinoma

Simple SummaryThe frequent occurrence of occult cervical lymph node metastasis is still a therapeutic challenge in oral squamous cell carcinoma (OSCC) and represents a limiting factor in terms of survival. The common staging of malignancy is not precise enough to predict the development of lymph node metastases and additional prognostic factors are needed. In this study we show that CD36, a protein related to fatty acid metabolism, is expressed in OSCC and correlates with the occurrence of lymph node metastasis. CD36 may be useful as a specific parameter for lymph node metastasis and as a progression parameter for survival. Therefore, CD36 could be useful for risk stratification regarding lymph node metastasis in OSCC and, beyond that, CD36 could also be a possible therapeutic target in future.Purpose: To investigate the expression pattern of CD36 in a patient population with oral squamous cell carcinoma (OSCC) and to correlate CD36 expression with clinical and histopathological parameters. The hypothesis was that CD36 expression correlates with the occurrence of lymph node metastasis. Methods: To address the study objectives, a retrospective cohort study was conducted. Study variables included demographic, histopathological and survival data. CD36 expression patterns were assessed by immunohistochemistry on tissue microarrays (TMA). Logistic regression analysis, survival analysis and Cox proportional hazards model were performed. Results: High CD36 expression correlated significantly with a higher T-status, grading and occurrence of lymph node metastasis. The logistic regression with binary N status as a dependent variable showed that high CD36 expression increased the chance for lymph node metastasis 45-fold (OR = 44.7, 95% CI: 10.0–316). Patients with high CD36 expression had lower probabilities of progression-free survival. CD36 had a small and non-significant independent influence on progression-free survival. Conclusions: CD36 is expressed in OSCC and correlates with tumor grading, T-status, and especially the occurrence of lymph node metastasis. CD36 may be useful for risk stratification regarding lymph node metastasis in OSCC.

MicroRNA-99a-5p suppresses cell proliferation, migration, and invasion by targeting isoprenylcysteine carboxylmethyltransferase in oral squamous cell carcinoma.

BackgroundMicroRNA (miR)-99a-5p acts as a tumor suppressor in several tumors, including bladder cancer and breast cancer, but its biological function in oral squamous cell carcinoma (OSCC) is poorly understood.MethodsmiR-99a-5p expression was determined in OSCC tissues and cell lines using quantitative reverse transcription polymerase chain reaction (RT-qPCR). Cell proliferation was assessed by the Cell Counting Kit-8 assay and colony formation assay. Wound healing and Transwell assays were used to analyze migration and invasion abilities, respectively, in OSCC cells. The luciferase reporter assay, RT-qPCR, and western blotting were used to determine the relationship between miR-99a-5p and isoprenylcysteine carboxylmethyltransferase (ICMT).ResultsmiR-99a-5p expression in OSCC tissues and cell lines was significantly decreased compared with corresponding controls, and was significantly associated with clinical stage and lymph node metastasis in OSCC. Functional assays revealed that miR-99a-5p overexpression significantly inhibited the proliferation, migration, and invasion abilities of CAL-27 and TCA-8113 OSCC cells. miR-99a-5p was found to directly target ICMT, while ICMT restoration reversed the role of miR-99a-5p in OSCC cells.ConclusionsOur results indicate that miR-99a-5p-mediates the down-regulation of ICMT, which could be used as a novel potential therapeutic target for OSCC treatment.

A Combined Prediction Model for Lymph Node Metastasis Based on a Molecular Panel and Clinicopathological Factors in Oral Squamous Cell Carcinoma

ObjectiveLymph node metastasis is the most important factor influencing the prognosis of oral squamous cell carcinoma (OSCC) patients. However, there is no proper method for predicting lymph node metastasis. This study aimed to construct and validate a preoperative prediction model for lymph node metastasis and guide personalized neck management based on the gene expression profile and clinicopathological parameters of OSCC.MethodsBased on a previous study of related genes in OSCC, the mRNA expression of candidate genes was evaluated by real-time PCR in OSCC specimens. In this retrospective study, the gene expression profile and clinicopathological parameters of 112 OSCC patients were combined to construct the best prediction model for lymph node metastasis of OSCC. The model was validated with 95 OSCC samples in this study. Logistic regression analysis was used. The area under the curve (AUC) ultimately determined the diagnostic value of the prediction model.ResultsThe two genes CDKN2A + PLAU were closely related to lymph node metastasis of oral squamous cell carcinoma. The model with the combination of CDKN2A, PLAU, T stage and pathological grade was the best in predicting lymph node metastasis (AUC = 0.807, 95% CI: 0.713-0.881, P=0.0001). The prediction model had a specificity of 96% and sensitivity of 72.73% for stage T1 and T2 OSCC (AUC = 0.855, 95% CI: 0.697-0.949, P=0.0001).ConclusionsHigh expression of CDKN2A and PLAU was associated with lymph node metastasis in OSCC. The prediction model including CDKN2A, PLAU, T stage and pathological grade can be used as the best diagnostic model for lymph node metastasis in OSCC.

PKD3 promotes metastasis and growth of oral squamous cell carcinoma through positive feedback regulation with PD-L1 and activation of ERK-STAT1/3-EMT signalling

Oral squamous cell carcinoma (OSCC) has a high incidence of metastasis. Tumour immunotherapy targeting PD-L1 or PD-1 has been revolutionary; however, only a few patients with OSCC respond to this treatment. Therefore, it is essential to gain insights into the molecular mechanisms underlying the growth and metastasis of OSCC. In this study, we analysed the expression levels of protein kinase D3 (PKD3) and PD-L1 and their correlation with the expression of mesenchymal and epithelial markers. We found that the expression of PKD3 and PD-L1 in OSCC cells and tissues was significantly increased, which correlated positively with that of mesenchymal markers but negatively with that of epithelial markers. Silencing PKD3 significantly inhibited the growth, metastasis and invasion of OSCC cells, while its overexpression promoted these processes. Our further analyses revealed that there was positive feedback regulation between PKD3 and PD-L1, which could drive EMT of OSCC cells via the ERK/STAT1/3 pathway, thereby promoting tumour growth and metastasis. Furthermore, silencing PKD3 significantly inhibited the expression of PD-L1, and lymph node metastasis of OSCC was investigated with a mouse footpad xenograft model. Thus, our findings provide a theoretical basis for targeting PKD3 as an alternative method to block EMT for regulating PD-L1 expression and inhibiting OSCC growth and metastasis.