Salivary IL-6 mRNA is a Robust Biomarker in Oral Squamous Cell Carcinoma

Longitudinal study on salivary IL-6 trajectories in postoperative OSCC patients after chemotherapy and radiotherapy

BACKGROUND

Oral squamous cell carcinoma (OSCC) poses a significant healthcare challenge globally, necessitating precise biomarkers for effective management. Interleukin-6 (IL-6) in saliva has emerged as a potential biomarker, yet its dynamics post-chemotherapy and radiotherapy remain underexplored.

AIM

The aim of our study is to investigate the longitudinal dynamics of salivary interleukin-6 (IL-6) expression in postoperative OSCC patients over a one-year follow-up period after chemotherapy and radiotherapy.

METHODS

This longitudinal study enrolled 60 participants, including postoperative OSCC patients and controls, collecting saliva samples over one year. RT-PCR and ELISA techniques measured IL-6 expression. Statistical analyses, including repeated measures ANOVA and univariate tests, evaluated IL-6 dynamics.

RESULTS

Pre-treatment, OSCC patients exhibited elevated IL-6 levels compared to controls. Post-therapy, IL-6 levels decreased significantly with p < .0001, indicating treatment response and further result to baseline normalizing at 6-month follow-up. Significant differences were observed across treatment stages, supporting IL-6 as a diagnostic and prognostic marker for OSCC. RT-PCR and ELISA results showed the statistical significance of IL-6's role as a predictive marker.

CONCLUSION

Salivary IL-6 emerges as a promising biomarker in OSCC management, necessitating further research to harness its diagnostic and therapeutic potential. By understanding IL-6 dynamics, personalized treatment approaches can be developed to improve patient outcomes. Longitudinal studies with larger cohorts and multi-omics approaches are warranted to validate findings and identify novel therapeutic targets.

Shaping the future of oral cancer diagnosis: advances in salivary proteomics

INTRODUCTION

Saliva has gained increasing attention in the quest for disease biomarkers. Because it is a biological fluid that can be collected is an easy, painless, and safe way, it has been increasingly studied for the identification of oral cancer biomarkers. This is particularly important because oral cancer is often diagnosed at late stages with a poor prognosis.

AREAS COVERED

The review addresses the evolution of the experimental approaches used in salivary proteomics studies of oral cancer over the years and outlines advantages and pitfalls related to each one. In addition, examines the current landscape of oral cancer biomarker discovery and translation focusing on salivary proteomic studies. This discussion is based on an extensive literature search (PubMed, Scopus and Google Scholar).

EXPERT OPINION

The introduction of mass spectrometry has revolutionized the study of salivary proteomics. In the future, the focus will be on refining existing methods and introducing powerful experimental techniques such as mass spectrometry with selected reaction monitoring, which, despite their effectiveness, are still underutilized due to their high cost. In addition, conducting studies with larger cohorts and establishing standardized protocols for salivary proteomics are key challenges that need to be addressed in the coming years.

Chemerin promotes invasion of oral squamous cell carcinoma by stimulating IL-6 and TNF-α production via STAT3 activation

AIMS

Elevated levels of adipokine chemerin have been identified in oral squamous cell carcinoma (OSCC) and found to be associated with metastasis to the cervical lymph nodes. The underlying mechanism through which chemerin affects OSCC progression is unclear. The aims of this study were firstly to determine chemerin levels and cytokine concentrations in serum from patients with OSCC and in OSCC cell cultures, and secondly to observe chemerin effects on OSCC cell cytokine secretion, migration, and invasion in vitro.

METHODS

Serum samples were collected from 20 patients diagnosed with OSCC, including groups with (LN+) and without (LN-) cervical lymph node metastasis. A Luminex liquid suspension assay was used to quantify serum concentrations of 27 types of cytokines. Correlations between chemerin and cytokines (i.e., IL-6, IL-15, GM-CSF, RANTES, TNF-α, and VEGF) were analyzed. ELISAs (enzyme-linked immunosorbent assays) were used to determine concentrations of chemerin and selected cytokines in serum and in supernatants of OSCC cell cultures (SCC9 and SCC25 cell lines). OSCC cells were stimulated with human recombinant chemerin, STAT3 inhibitor, or IL-6 together with TNF-α neutralizing antibodies. Phosphorylated STAT3 protein levels were measured with western blot analysis. OSCC cell migration and invasion were investigated with Transwell assays.

RESULTS

Compared to the LN- group, OSCC patients with cervical lymph node metastasis had higher levels of IL-6 (P = 0.006), IL-15 (P = 0.020), GM-CSF (P = 0.036), RANTES (P = 0.032), TNF-α (P = 0.005), VEGF (P = 0.006), and chemerin (P = 0.001). Patients' serum chemerin levels correlated directly with IL-6, GM-CSF, TNF-α, and VEGF levels in OSCC patients. Exogenous recombinant chemerin treatment promoted secretion of IL-6 and TNF-α via activation of STAT3 in OSCC cells. Chemerin induced OSCC-cell migration and invasion, and these effects were reduced by IL-6 and TNF-α neutralizing antibodies.

CONCLUSION

Our findings indicate that chemerin may play a role in advancing OSCC progression by increasing production of IL-6 and TNF-α, perhaps via a mechanism involving STAT3 signaling.

Salivary Chemical Barrier Proteins in Oral Squamous Cell Carcinoma-Alterations in the Defense Mechanism of the Oral Cavity

Oral squamous cell carcinoma (OSCC) is one of the most frequent types of head and neck cancer. Despite the genetic and environmental risk factors, OSCC is also associated with microbial infections and/or dysbiosis. The secreted saliva serves as the chemical barrier of the oral cavity and, since OSCC can alter the protein composition of saliva, our aim was to analyze the effect of OSCC on the salivary chemical barrier proteins. Publicly available datasets regarding the analysis of salivary proteins from patients with OSCC and controls were collected and examined in order to identify differentially expressed chemical barrier proteins. Network analysis and gene ontology (GO) classification of the differentially expressed chemical barrier proteins were performed as well. One hundred and twenty-seven proteins showing different expression pattern between the OSCC and control groups were found. Protein-protein interaction networks of up- and down-regulated proteins were constructed and analyzed. The main hub proteins (IL-6, IL-1B, IL-8, TNF, APOA1, APOA2, APOB, APOC3, APOE, and HP) were identified and the enriched GO terms were examined. Our study highlighted the importance of the chemical barrier of saliva in the development of OSCC.

The role of p21-activated kinase 4 in the progression of oral squamous cell carcinoma by targeting PI3K-AKT signaling pathway

BACKGROUND

Oral squamous carcinoma (OSCC), the most common head and neck malignancy, has a strong propensity for malignant proliferation and metastasis, which will decrease the survival of patients. P21-activated kinase 4 (PAK4), a classical serine/threonine protein kinase with multiple cellular functions, has an essential role in cancer cell migration and invasion. Here, we elucidated the function and possible molecular mechanisms of the effect of PAK4 on the biological behaviors of OSCC.

METHODS

The expression of genes and protein was detected by real-time PCR and western blotting. We used oral squamous carcinoma cell lines, Tca8117, Cal 27, SCC 4, and SCC 9 for validation of our cell function data. Flow cytometry, 3D cultures, and clone formation assay were used to detect proliferation of cells. RNA sequencing and bioinformatic analysis was performed to determine the potential function of PAK4.

RESULTS

Immunohistochemistry, western blotting and real-time PCR demonstrated that PAK4 expression was up-regulated in OSCC tissues. Overexpression of PAK4 promoted the proliferation, migration and invasion of OSCC cell lines. RNA sequencing (RNA-seq) for the transcriptome-wide analysis of differential gene expression followed by bioinformatic analysis was performed to determine the potential function of PAK4. Based on the KEGG enrichment analysis and GO analysis of differential expression genes (DEGs) we found that PAK4 promotes the cell-cycle machinery, which associated with 44 regulated genes, thereby promoting cancer cell differentiation.

CONCLUSIONS

This study demonstrates that the PAK4 regulates the biological behaviors of OSCC by PI3K-AKT signaling pathway, and these findings might provide a novel strategy for OSCC treatment.

Salivary Interleukin Levels in Oral Squamous Cell Carcinoma and Oral Epithelial Dysplasia: Findings from a Sri Lankan Study

The incidence of oral squamous cell carcinoma (OSCC), and its precursor, oral epithelial dysplasia (OED), is on the rise, especially in South Asia. OSCC is the leading cancer in males in Sri Lanka, with >80% diagnosed at advanced clinical stages. Early detection is paramount to improve patient outcome, and saliva testing is a promising non-invasive tool. The aim of this study was to assess salivary interleukins (lL1β, IL6, and IL8) in OSCC, OED and disease-free controls in a Sri Lankan study cohort. A case-control study with OSCC (n = 37), OED (n = 30) patients and disease-free controls (n = 30) was conducted. Salivary lL1β, IL6, and IL8 were quantified using enzyme-linked immuno-sorbent assay. Comparisons between different diagnostic groups and potential correlations to risk factors were assessed. Salivary levels for the three tested interleukins increased from disease-free controls through OED, and were highest in OSCC samples. Furthermore, the levels of IL1β, IL6, and IL8 increased progressively with OED grade. The discrimination between patients (OSCC and OED) and controls, as assessed by AUC of receiver operating characteristic curves, was 0.9 for IL8 (p = 0.0001) and 0.8 for IL6 (p = 0.0001), while IL1β differentiated OSCC from controls (AUC 0.7, p = 0.006). No significant associations were found between salivary interleukin levels and smoking, alcohol, and betel quid risk factors. Our findings suggest that salivary IL1β, IL6, and IL8 are associated with disease severity of OED, and are potential biomarkers for predicting disease progression in OED, and the screening of OSCC.

Saliva - a new opportunity for fluid biopsy

Saliva is a complex biological fluid with a variety of biomolecules, such as DNA, RNA, proteins, metabolites and microbiota, which can be used for the screening and diagnosis of many diseases. In addition, saliva has the characteristics of simple collection, non-invasive and convenient storage, which gives it the potential to replace blood as a new main body of fluid biopsy, and it is an excellent biological diagnostic fluid. This review integrates recent studies and summarizes the research contents of salivaomics and the research progress of saliva in early diagnosis of oral and systemic diseases. This review aims to explore the value and prospect of saliva diagnosis in clinical application.

MAPK Signaling Pathway in Oral Squamous Cell Carcinoma: Biological Function and Targeted Therapy

Oral squamous cell carcinoma accounts for 95% of human head and neck squamous cell carcinoma cases. It is highly malignant and aggressive, with a poor prognosis and a 5-year survival rate of <50%. In recent years, basic and clinical studies have been performed on the role of the mitogen-activated protein kinase (MAPK) signaling pathway in oral cancer. The MAPK signaling pathway is activated in over 50% of human oral cancer cases. Herein, we review research progress on the MAPK signaling pathway and its potential therapeutic mechanisms and discuss its molecular targeting to explore its potential as a therapeutic strategy for oral squamous cell carcinoma.

Interleukin-6 mediated inflammasome activation promotes oral squamous cell carcinoma progression via JAK2/STAT3/Sox4/NLRP3 signaling pathway

Background

Interleukin-6 (IL-6) has been reported to be critical in oral squamous cell carcinoma (OSCC). However, the set of pathways that IL-6 might activate in OSCC are not fully understood.

Methods

IL-6 and Sox4 expressions were first determined with RT-qPCR, ELISA, Western blot, or immunohistochemistry in OSCC tissues, and correlations between IL-6 and Sox4 expression and patient pathological characteristics were examined, and Kaplan–Meier approach was employed for evaluating the prognostic utility in OSCC patients. CCK-8, EdU stain and colony formation assays were utilized to test cell proliferation in vitro. Mechanistically, downstream regulatory proteins of IL-6 were verified through chromatin immunoprecipitation, luciferase reporter, pull-down, and the rescued experiments. Western blot was used for detecting protein expression. A nude mouse tumorigenicity assay was used to confirm the role of IL-6 and Sox4 in vivo.

Results

IL-6 was upregulated in OSCC tissues, and Sox4 expression was positively correlated with IL-6 expression. High IL-6 and Sox4 expression was closely related to tumor size, TNM stage, and a poorer overall survival. Besides, IL-6 could accelerate OSCC cell proliferation by activating inflammasome via JAK2/STAT3/Sox4/NLRP3 pathways in vitro and in vivo. Furthermore, STAT3 played as a transcription factor which positively regulated Sox4, and IL-6 promotes Sox4 expression by activating JAK2/STAT3 pathway. Moreover, through the rescue experiments, we further confirmed that IL-6 could promote proliferation and NLRP3 inflammasome activation via JAK2/STAT3/Sox4 pathway in OSCC cells. Finally, knockdown of Sox4 suppressed OSCC growth in vivo, and antagonized the acceleration of IL-6 on tumor growth.

Conclusions

We confirmed that IL-6 plays an oncogenic role in OSCC progression by activating JAK2/STAT3/Sox4/NLRP3 pathway, which might be the therapeutic targets for OSCC remedy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02376-4.

Fadu head and neck squamous cell carcinoma induces hyperexcitability of primary sensory neurons in an in vitro coculture model

Supplemental Digital Content is Available in the Text.

Squamouscell carcinoma cells promoted an inflammatory microenvironment and induced sensitization of both human and rat dorsal root ganglion neurons in patch clamp electrophysiology recordings.

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IL-6 Promoter Hypomethylation Acts As a Diagnostic Biomarker in Hepatitis B Virus-Associated Hepatocellular Carcinoma

Background

New biomarkers are needed to detect hepatocellular carcinoma at an earlier stage and to individualize treatment strategies. IL-6 has been proven to be associated with liver cancer in numerous studies.

Aim

To evaluate the value of the IL-6 promoter methylation level as a noninvasive biomarker for the diagnosis of liver cancer.

Methods

A retrospective analysis of 165 patients with HBV-associated hepatocellular carcinoma (HCC), 198 patients with chronic hepatitis B (CHB) and 31 healthy controls were involved. The methylight was detected the methylation level of the IL-6 promoter in peripheral blood mononuclear cells (PBMCs), clinical and laboratory parameters were obtained.

Results

IL-6 promoter methylation levels were significantly lower in patients with HCC (median 53.59%, interquartile range 52.01–54.75%) than in those with CHB (median 56.05%, interquartile range 54.65–57.67%; P<0.001). The level of IL-6 mRNA in patients with HCC (median 0.371, interquartile range 0.173-0.671) was significantly higher than that in patients with CHB (median 0.203, interquartile range 0.108-0.354; P<0.001) and HCs (median 0.189, interquartile range 0.140-0.262; P=0.001). Meanwhile, the PMR value of IL-6 was notably negatively correlated with the mRNA expression level (Spearman’s R=-0.201, P<0.001). The IL-6 PMR value of HCC patients in age (Spearman’s R=0.193, P=0.026) and TBIL (Spearman’s R=0.186, P=0.032) were very weak correlated. At the same time, the level of IL-6 promoter methylation was also an independent factor in the development of liver cancer. When the IL-6 promoter methylation level was used to diagnose HCC, its detective value was superior to AFP [area under the receiver operating characteristic curve (AUC) 0.773 vs. 0.686, P=0.027], And the combined use of AFP and IL-6 methylation level can improve the area under the receiver operating characteristic curve (p=0.011).

Conclusion

IL-6 promoter hypomethylation is present in hepatocellular carcinoma, and it may be used as a noninvasive biomarker to detect early liver cancer.

Salivary miR-31-5p, miR-345-3p, and miR-424-3p Are Reliable Biomarkers in Patients with Oral Squamous Cell Carcinoma

If not detected early, oral squamous cell carcinoma (OSCC) has very poor prognosis, emphasizing the need for reliable early diagnostics. Saliva is considered a promising surrogate biosample for OSCC detection, because it comes into contact with many cells of the tumor mass, providing a comprehensive sampling of tumor-specific biomolecules. Although several protein- and RNA-based salivary biomarkers have been proposed for the detection of OSCC, the results of the studies show large differences. Our goal was to clarify which salivary microRNAs (miRNA) show reliably high expression in the saliva of OSCC patients, to be used as cancer-specific biomarkers, and potentially as early diagnostic biomarkers. Based on a detailed literature search, we selected six miRNAs commonly overexpressed in OSCC, and analyzed their expression in saliva samples of cancer patients and controls by real-time quantitative PCR. Our results suggest that miR-345 and miR-31-5p are consistently upregulated salivary biomarkers for OSCC, and a three-miRNA panel of miR-345, miR-31-5p, and miR-424-3p can distinguish cancer and control patients with high sensitivity.

Usefulness of protein-based salivary markers in the diagnosis of oral potentially malignant disorders: A systematic review and meta-analysis

By using a meta-analytical approach, this study aimed to analyse the diagnostic capacity of protein-based biomarkers in saliva for the differential diagnosis of oral potentially malignant disorders (OPMDs) and oral squamous cell carcinoma (OSCC) from healthy individuals as control group (HCG).Articles on protein-based biomarkers in saliva, which provided quantitative expression in individuals with clinical and histopathological diagnosis of OPMD or oral leukoplakia (OL) were considered eligible. Searches were conducted in eight electronic databases. The methodological quality was assessed using the Quality Assessment of Diagnostic Studies tool (QUADAS-2). Functional analysis was also performed. Meta-analyses were performed using the OpenMeta tool (Analyst).Meta-analysis was possible for 4 of the 11 biomarkers studied. Only the carcinoembryonic antigen (CEA) and the soluble fragment of cytokeratin 19 (CYFRA21) were significant for the OSCC/OPMD subgroup, both with a very low heterogeneity. CEA had an OE = 25.854 (CI95%: 13.215-38.492, p< 0.001, I2 = 0) and CYFRA21 had an OE = 9.317 (CI95%: 9.014-9.619, p< 0.001, I2 = 0). For the OPMD/HCG subgroup, only CYFRA21 was significant, with an OE = 3.679 (CI95%: 0.663-6.696, p= 0.017) although with high heterogeneity (I2 = 91.24).The CEA and CYFRA21 markers proved very useful when differentiating OSCC from OPMD. The CYFRA21 was the only protein that was capable of distinguishing between OPMD and healthy controls.

Diagnostic salivary biomarkers in oral cancer and oral potentially malignant disorders and their relationships to risk factors - A systematic review

INTRODUCTION

Oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMD) are a significant health burden globally. Smoking, alcohol, and betel quid are the main risk factors. Lack of screening methods has been highlighted as a significant challenge in management. Salivary biomarkers are proposed as noninvasive diagnostic tools. The aim of this systematic review was to study salivary biomarkers reported in OSCC and OPMD. Specific objectives were to select a salivary biomarker panel suitable for early detection of OSCC and OPMD and to assess relationships between salivary biomarkers and risk factors.

METHODS

Electronic literature search was conducted in academic databases (Scopus, Medline, Embase and Web of Science) without any restrictions. Following calibration, two blinded reviewers screened the studies and extracted data. A risk of bias assessment was conducted using Newcastle Ottawa scale. 295 studies were included with descriptive data analysis.

EXPERT OPINION

A salivary biomarker panel including Interleukin (IL) 1β, IL6, and IL8 was selected for OSCC and OPMD. Reported relationships between salivary biomarkers and risk factors are discussed and research gaps are highlighted. Future research should be directed to assess potential salivary biomarkers and their relationships to risk factors in order to understand the biomarker's role in disease initiation.

Examination of Oral Squamous Cell Carcinoma and Precancerous Lesions Using Proximity Extension Assay and Salivary RNA Quantification

Saliva is an easy-to access body fluid with high diagnostic potential. The utilization of saliva for oral cancer diagnosis can be an attractive possibility. Besides the oral cancer, it is important to better understand the precancerous lesions such as oral lichen planus (OLP) and leukoplakia (OLK). In order to examine the changes of salivary proteins in controls, patients with oral cancer, and patients with precancerous conditions, proximity extension assay was utilized. Some proteins and functions were characteristic to the examined groups and can serve as a starting point for further biomarker studies. The different nature of OLK and OLP was demonstrated, showing the malignant transformation and the inflammation as the prominent biological processes in the OLK and OLP, respectively. The salivary level of IL6 was verified using quantitative ELISA and the mRNA level was also studied. Elevated IL6 levels could be detected in precancerous groups compared to controls.

Anti-Proliferative Effect of Statins Is Mediated by DNMT1 Inhibition and p21 Expression in OSCC Cells

Statins, also known as HMG-CoA reductase inhibitors, are a class of cholesterol-lowering drugs and their anti-cancer effects have been studied in different types of malignant diseases. In the present study, we investigated the anti-proliferative effects of statins, including cerivastatin and simvastatin, on oral squamous cell carcinoma (OSCC) cells. Our data showed that statins inhibited the proliferation of three OSCC cell lines in a dose-dependent manner and this growth inhibition was confirmed through G₀/G₁ cell cycle arrest. Accordingly, we found the upregulation of p21 and downregulation of cyclin-dependent kinases, including CDK2, CDK4, and CDK6, in the statin-treated cells. Importantly, we clearly showed that statins were able to inhibit the expression of DNA methyltransferase 1 (DNMT1) and further promote the expression of p21. Taken together, our data demonstrated that the anti-proliferative effect of statins is mediated by suppressing DNMT1 expression, thus promoting p21 expression and leading to G₀/G₁ cell cycle arrest in OSCC cells.

Sushi Repeat Containing Protein X-linked 2 Is a Downstream Signal of LEM Domain Containing 1 and Acts as a Tumor-Promoting Factor in Oral Squamous Cell Carcinoma

Because oral squamous cell carcinomas (OSCCs) have a high potential for locoregional invasion and nodal metastasis, early detection and treatment are essential. A LAP2, emerin, MAN1 (LEM) domain containing 1 (LEMD1) is associated with local progression, clinical stage, nodal metastasis, poor prognosis, angiogenesis, and lymphangiogenesis in OSCC. Although LEMD is a cancer-testis antigen, the cancer-related signals related to LEMD1 remain unknown. In this study, we used a microarray analysis of OSCC cells to identify sushi repeat containing protein X-linked 2 (SRPX2) as a LEMD1-related downstream signal. LEMD1 expression was correlated with lymph node metastasis of OSCC according to the immunohistochemistry analysis. Furthermore, patients expressing SRPX2 had a significantly worse prognosis than those without SRPX2 expression. The concentration of SRPX2 in OSCC was positively correlated with the concentrations of LEMD1, urokinase plasminogen activator receptor (uPAR), and hepatocyte growth factor (HGF). In OSCC cells, SRPX2 secretion levels were elevated by interactions with uPAR and HGF. We also found that SRPX2 promotes endothelial cell proliferation and adhesion between endothelial cells and OSCC cells. These results suggest that SRPX2 might be a useful tumor marker for OSCC.