Salivary inflammatory proteins in patients with oral potentially malignant disorders

Expression of salivary levels of S100A7 in oral submucous fibrosis and oral leukoplakia

Aim

The aim of the study is to evaluate the expression of S100A7 levels in saliva of oral sub-mucous fibrosis, oral leukoplakia patients, and healthy control.

Materials and Methods

The study comprised of saliva samples from 15 patients each with clinically diagnosed oral sub-mucous fibrosis, oral leukoplakia, and healthy control. Salivary S100A7 levels were estimated using Enzyme-Linked Immunosorbent Assay. Statistical analysis was performed using SPSS. The significance level is fixed at 5% (α = 0.05). To compare the mean values of concentration between the disease group oral leukoplakia (OL) and oral submucous fibrosis (OSMF) and control, one-way analysis of variance was used followed by a post hoc test for multiple pairwise comparisons.

Results

The results of the study indicated a statistically significant increase in the salivary S100A7 level among the OSMF and OL when compared with the control group. When a pairwise comparison was done between OSMF with a control group and leukoplakia with a control group, a statistically significant difference was observed, subsequently while comparing OSMF with leukoplakia, and no statistically significant difference was observed.

Conclusion

Results from this study demonstrated increased S100A7 levels in OSMF and OL when compared with control group. This indicated that salivary S100A7 can be used as an adjunctive marker to identify patients at risk of progression into oral squamous cell carcinoma (OSCC).

Associations between salivary cytokines and oral health, age, and sex in healthy children

Human saliva is a complex fluid containing proteins such as salivary cytokines, which can be used for diagnostic purposes, particularly among the pediatric population. This study aimed to assess the concentrations of salivary cytokines in healthy children and adolescents and determine their associations with age, sex, and oral and dental findings. Healthy children and adolescents aged 4–18 years were enrolled in this cross-sectional study. The concentrations of the following salivary cytokines were measured by Luminex technology: IFN-γ, IL-1α, IL-1β, IL-4, IL-5, IL-6, IL-8, IL-10, IL-13, IP-10, TNF-α, and VEGF-A. Additionally, oral and dental parameters were recorded using a standardized protocol. A total of 128 participants (mean age, 10.7 years; males, 50.8%) were enrolled. The levels of 1β, IL-6, IL-8, and IL-10 were significantly higher in those with gingivitis. Increased salivary flow rates were negatively correlated with IL-1α, IL-1β, IL-6, IL-8, IL-10, TNF-α, and VEGF-A concentrations. The findings of this study showed that the concentrations of most of the salivary cytokines were positively correlated with age and the presence of oral pathologies (such as gingivitis and caries) and negatively correlated with salivary flow rate.

Probiotics as Potential Biological Immunomodulators in the Management of Oral Lichen Planus: What's New?

Oral lichen planus (OLP) is a T cell-mediated chronic inflammatory disorder with multifactorial aetiology and malignant transformation potential. Despite the treatments so far identified, new tailored and safe specific measures are needed. Recently, human microbiota imbalance has been linked to several immune-mediated diseases, opening new therapeutic perspectives for probiotics; besides their ability to directly interact with the host microbiota, they also display a strain-specific immune-modulatory effect. Thus, this non-systematic review aims to elucidate the molecular pathways underlying probiotic activity, mainly those of Lactobacilli and Bifidobacteria and their metabolites in OLP pathogenesis and malignant transformation, focusing on the most recent in vitro and in vivo research evidence. Findings related to their activity in other immune-mediated diseases are here included, suggesting a probiotic translational use in OLP. Probiotics show immune-modulatory and microbiota-balancing activities; they protect the host from pathogens, hamper an excessive effector T cell response, reduce nuclear factor-kappa B (NF-kB) signalling and basal keratinocytes abnormal apoptosis, shifting the mucosal response towards the production of anti-inflammatory cytokines, thus preventing uncontrolled damage. Therefore, probiotics could be a highly encouraging prevention and immunotherapeutic approach for a safer and more sustainable OLP management.

[Research Updates: The Role of Interaction between Oral Microbiota, Immune Cells, and Epithelial Barrier in Oral Mucosal Homeostasis and Pathogenesis]

In a healthy state, the interaction between the oral microorganisms, mucosal immune cells and epithelial barrier can maintain the oral microecological stability. However, the oral microecology is disrupted under a diseased state and various pathogenic bacteria and their virulence factors and metabolites irritate the immune system, which causes direct or indirect damage to the epithelial barrier, promotes the pathogenesis and progression of oral mucosal diseases, and triggers immune inflammatory response or the irreversible transformation from inflammation into cancer. We herein reviewed the interaction between oral microorganisms, immune cells and epithelial barrier from two perspectives, the maintenance of the oral homeostasis and the pathogenesis of oral mucosal diseases. We intended to gain further understanding of the oral mucosal homeostasis and the mechanism of action of the pathogenesis and progression of oral mucosal diseases, and to provide thereby ideas and scientific and theoretical basis for developing new strategies for the diagnosis and treatment of oral mucosal diseases through re-establishing mucosal homeostasis.

Inflammatory Mediators in Oral Cancer: Pathogenic Mechanisms and Diagnostic Potential

Approximately 15% of cancers are attributable to the inflammatory process, and growing evidence supports an association between oral squamous cell carcinoma (OSCC) and chronic inflammation. Different oral inflammatory conditions, such as oral lichen planus (OLP), submucous fibrosis, and oral discoid lupus, are all predisposing for the development of OSCC. The microenvironment of these conditions contains various transcription factors and inflammatory mediators with the ability to induce proliferation, epithelial-to-mesenchymal transition (EMT), and invasion of genetically predisposed lesions, thereby promoting tumor development. In this review, we will focus on the main inflammatory molecules and transcription factors activated in OSCC, with emphasis on their translational potential.

Crosstalk between the oral microbiota, mucosal immunity, and the epithelial barrier regulates oral mucosal disease pathogenesis

Oral mucosal disease (OMD), which is also called soft tissue oral disease, is described as a series of disorders or conditions affecting the mucosa and soft tissue in the oral cavity. Its etiology is unclear, but emerging evidence has implicated the influence of the composition of the oral mucosa and saliva-resident microbiota. In turn, this dysbiosis effects the immune response balance and epithelial barrier function, followed by the occurrence and progression of OMD. In addition, oral microbial dysbiosis is diverse in different types of diseases and different disease progressions, suggesting that key causal pathogens may exist in various oral pathologies. This narrative literature review primarily discusses the most recent findings focusing on how microbial dysbiosis communicates with mucosal adaptive immune cells and the epithelial barrier in the context of five representative OMDs, including oral candidiasis (OC), oral lichen planus (OLP), recurrent aphthous ulcer (RAU), oral leukoplakia (OLK), and oral squamous cell carcinoma (OSCC), to provide new insight into the pathogenetic mechanisms of OMDs.

GP88/PGRN Serum Levels Are Associated with Prognosis for Oral Squamous Cell Carcinoma Patients

Simple Summary

An oral squamous cell carcinoma (OSCC) is a tumor of the oral cavity that has a five-year survival rate of only around 50%. As this rate has not increased in recent decades, despite improvements in diagnosis and therapy, novel, easily accessible biomarkers for prognosis assessment are still needed. In our study, we measured the growth factor protein progranulin/GP88 in the serum of OSCC patients and demonstrated that an increased serum GP88 level is associated with a better prognosis for the OSCC patients in our study group. Furthermore, serum GP88 levels were not significantly associated with age, sex, or the tumor’s histological features, indicating that serum GP88 levels may be an independent predictor of an individual OSCC patient’s prognosis. These findings may help to improve therapy management of an OSCC in personalized medicine.

Abstract

Progranulin (PGRN)/GP88 is a growth factor that is expressed in a wide range of tumor tissues. The secreted form is involved in various biological processes including proliferation and inflammation. In several tumor types, the serum GP88 level is associated with a patient’s prognosis; however, data for oral squamous cell carcinomas (OSCCs) have not yet been reported. We measured the serum GP88 levels in 96 OSCC patients by an enzyme immunosorbent assay (EIA) and correlated these data with clinicopathological parameters and patient outcomes. The GP88 levels in the serum of OSCC patients and healthy volunteers were comparable. In OSCC patients, the levels did not correlate with age, sex, or TNM status. In a Kaplan–Meier survival analysis, a serum GP88 level < 68 ng/mL was significantly associated with worsened survival (p = 0.0005, log-rank-test) as well as in uni- and multivariate Cox regression analyses (RR = 4.6 [1.6–12.9], p = 0.004 and RR = 4.2 [1.2–12.0], p = 0.008). This effect was predominant in OSCC patients older than 60.5 years (p = 0.027), while in younger patients no significant association between serum GP88 levels and prognosis could be observed. Altogether, lower serum GP88 levels are significantly associated with a worsened outcome for an OSCC and may be an interesting candidate for risk stratification during OSCC therapy.

Potential Non-Invasive Biomarkers for Early Diagnosis of Oral Squamous Cell Carcinoma

This study aimed to investigate the role of a panel of salivary cytokines as biomarkers for early detection oral squamous cell carcinoma (OSCC), comparing their levels among healthy individuals, patients with oral leukoplakia (OL), and malignant lesions. Cytokine profiling analysis performed in a minimally invasive sample was correlated with clinicopathological variables in our patient cohorts. Unstimulated saliva was obtained from subjects with OSCC at early (n = 33) and advanced (n = 33) disease, OL with homogeneous (n = 33) and proliferative verrucous (n = 33) clinical presentations, and healthy controls (n = 25). Salivary IL-1α, IL-6, IL-8, IP-10, MCP-1, TNF-α, HCC-1, and PF-4 levels were analyzed by a sensitive bead-based multiplex immunoassay. Mean levels of IL-6, IL-8, TNF-α, HCC-1, MCP-1, and PF-4 differed significantly between OSCC, OL, and control saliva (p < 0.05). We found notably higher IL-6 and TNF-α in advanced compared to early OSCC stages. The area under the curve (AUC) for OSCC vs. control was greater than 0.8 for IL-6, IL-8, TNF-α, and HCC-1, and greater than 0.7 for PF-4. The presence of neck metastases (NM) was associated with increased IL-6 and TNF-α levels. Our findings suggest that salivary IL-6, IL-8, TNF-α, HCC-1, and PF-4 may discriminate between OSCC, OL, and healthy controls. IL-6 and TNF-α may indicate OSCC progression, being distinctive in the presence of NM.

The association of Candida and antifungal therapy with pro-inflammatory cytokines in oral leukoplakia

OBJECTIVES

To study the association of Candida and antifungal therapy with pro-inflammatory cytokines (PIC) in oral leukoplakia (OL).

MATERIALS AND METHODS

A prospective observational study where immunocompetent adult subjects with OL (30 homogenous (HL), 30 non-homogenous (NHL)) and 30 age and sex-matched healthy controls (C) with no predisposing factors for oral Candida infection were recruited. Sterile cotton swabs and ophthalmic sponges were used to sample the lesion surface in OL and buccal mucosa in C, for direct microscopy and culture for Candida and to determine levels of PIC (IL-6, IL-8. IL-17, TNF-α) by ELISA, respectively. Sampling for PIC was repeated at same sites in OL, 2 weeks after antifungal therapy.

RESULTS

Candida was associated with 55.3% of NHL, 23.3% of HL and 13.3% of C. The oral secretary levels of PIC were raised in NHL as compared to HL and C. The levels of IL-6, IL-8, TNF-α (p<0.001) and IL-17 (p<0.01) were significantly raised in Candida positive NHL while IL-6 (p<0.05) and TNF-α (p<0.01) were significantly raised in Candida positive HL before antifungal treatment. After antifungal treatment, there was significant reduction in PIC in Candida positive NHL and HL.

CONCLUSIONS

Candida infection contributes to the inflammatory milieu in Candida associated OL which increases the risk of carcinogenesis. Antifungal therapy reduces the PIC in Candida associated OL.

CLINICAL RELEVANCE

Identification and elimination of predisposing factors for Candida infection, like cessation of harmful habits, maintenance of oral/denture hygiene, surveillance for Candida and antifungal therapy at intervals, are recommended in OL.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04712929.

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.

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

Salivary IL-6 mRNA was previously identified as a promising biomarker of oral squamous cell carcinoma (OSCC). We performed a multi-center investigation covering all geographic areas of Hungary. Saliva from 95 patients with OSCC and 80 controls, all Caucasian, were collected together with demographic and clinicopathological data. Salivary IL-6 mRNA was quantified by real-time quantitative PCR. Salivary IL-6 protein concentration was measured by enzyme-linked immune-sorbent assay. IL-6 protein expression in tumor samples was investigated by immunohistochemistry. Normalized salivary IL-6 mRNA expression values were significantly higher (p < 0.001) in patients with OSCC (mean ± SE: 3.301 ± 0.885) vs. controls (mean ± SE: 0.037 ± 0.012). Differences remained significant regardless of tumor stage and grade. AUC of the ROC curve was 0.9379 (p < 0.001; 95% confidence interval: 0.8973–0.9795; sensitivity: 0.945; specificity: 0.819). Salivary IL-6 protein levels were significantly higher (p < 0.001) in patients (mean ± SE: 70.98 ± 14.06 pg/mL), than in controls (mean ± SE: 12.45 ± 3.29). Specificity and sensitivity of IL-6 protein were less favorable than that of IL-6 mRNA. Salivary IL-6 mRNA expression was significantly associated with age and dental status. IL-6 manifestation was detected in tumor cells and tumor-infiltrating leukocytes, suggesting the presence of a paracrine loop of stimulation. Salivary IL-6 mRNA is one of the best performing and clinically relevant biomarkers of OSCC.