Serum and salivary sialic acid as a biomarker in oral potentially malignant disorders and oral cancer

Clinical validation of a saliva-based matrix metalloproteinase-1 rapid strip test for detection of oral cavity cancer

BACKGROUND

We previously identified matrix metalloproteinase-1 (MMP-1) as one of the most promising salivary biomarkers for oral squamous cell carcinoma (OSCC) and developed a sensitive ELISA for MMP-1 with good performance in detection of OSCC using a cohort of 1160 saliva samples.

METHODS

A time-saving rapid strip test (RST) for MMP-1 was developed in this study and its diagnostic performance compared with ELISA using saliva samples from a new cohort of 603 subjects (171 healthy controls, 236 patients with oral potentially malignant disorders, and 196 OSCC patients).

RESULTS

Salivary MMP-1 levels measured using RST and ELISA were highly comparable and both assays could effectively distinguish between OSCC and non-cancerous groups. Similar to ELISA, receiver operating characteristic curve analysis of the MMP-1 RST was effective in identifying patients with OSCC at different oral cavity sites and stages.

CONCLUSIONS

Salivary MMP-1 can be sensitively detected using both RST and ELISA methods. Our newly developed point-of-care MMP-1 RST is a promising in vitro diagnostic device (IVD) that may serve as a novel auxiliary tool in the routine clinical detection and monitoring of OSCC.

The diagnostic effectiveness of serum sialic acid predicts both qualitative and quantitative prostate cancer in patients with prostate-specific antigen between 4 and 20 ng/mL

Introduction

This study aimed to evaluate the predictive value of the serum biochemical index, including alkaline phosphatase (AKP), lactate dehydrogenase (LDH), α-L-fucosidase (AFU), serum sialic acid (SA), and fibrinogen (FIB), for prostate cancer (PCa) and clinically significant prostate cancer (CSPCa) in patients with a prostate-specific antigen (PSA) value between 4 and 20 ng/mL.

Patients and methods

This study retrospectively examined the clinical data of 408 eligible patients who underwent prostate biopsies in our hospital between March 2015 and July 2022. CSPCa was defined as a "Gleason grade group of≥2". For analyzing the association between PCa/CSPCa and serum biochemical index, univariable logistic regression and multivariable logistic regression were conducted. Based on the multivariable logistic regression model, we constructed models and compared the area under the curve (AUC). We generated the nomogram, the ROC curve, the DCA curve, and the calibration curve for PCa.

Results

Overall, we studied 271 patients with PCa (including 155 patients with CSPCa) and 137 non-PCa patients. Patients with PCa were more likely to consume alcohol, have higher total PSA (TPSA) values, and have lower free PSA (FPSA) and free/total PSA (f/T) values. There were higher TPSA values and lower f/T values in the CSPCa group when compared with the non-CSPCa group. The univariate logistic regression analyses did not show significant results. However, AKP, AFU, SA, TPSA, and FPSA all retain significant significance when all factors are included in multifactor logistic regression analysis. This finding suggests that the exposure factor exhibited an independent effect on the outcome after controlling for other factors, including the potential confounding effects that may have been underestimated. Through ROC curves, we found that SA and TPSA levels are more powerful predictors. In contrast, there is a lack of excellent predictive value for PCA and CSPCa using Age, AFU, FIB, and FPSA.

Conclusion

In our study, serum biochemical index is a potential prediction tool for PCa and CSPCa for patients with PSA values between 4 and 20 ng/mL. Additionally, the new serum biochemical index SA is also useful when diagnosing PCa and CSPCa, as we conclude in our study.

Correlating Salivary Levels of Immunoglobin E and Human Eosinophil Cationic Protein in the Aseer Cohort with Recurrent Apthous Stomatitis

Background

Repeated Aphthous Stomatitis (RAS) is the most prevalent inflammatory disorder of the oral mucosa, characterized by recurrent emergence of single or numerous painful ulcers. RAS usually affects healthy people without systemic illnesses. There is evidence linking atopy to the progression of this illness. Immunoglobulin E (IgE) and human eosinophil cationic protein (HECP) levels in the saliva of individuals with aphthous stomatitis were assessed as allergy-related indicators.

Materials and Methods

Sixty people were assessed for this study. 30 patients with RAS were included in the patient group, while 30 healthy individuals made up for the control group. Sixty participants' non-stimulated saliva was taken and IgE and HECP were evaluated using enzyme-linked immunosorbent assay (ELISA). Data were analyzed in SPSS 20 through the Mann-Whitney test and p<0.05 was considered significant.

Results

The salivary level of HECP was significantly (p 0.05) higher among cases (0.83 0.70) compared to controls (0.170 0.15), whereas the salivary level of IgE was not significantly (p = 0.41) higher among cases (35.60 11.19) compared to controls (67.42 18.34).

Conclusion

Even though this study found a positive correlation between elevated HECP levels and RAS, additional research with larger sample sizes is required to identify the biological mechanisms responsible for the observed associations and to include salivary HECP levels in the RAS patient's evaluation.

Neu5Ac Induces Human Dental Pulp Stem Cell Osteo-/Odontoblastic Differentiation by Enhancing MAPK/ERK Pathway Activation

Dental pulp stem cells (DPSCs) must undergo odontoblastic differentiation in order to facilitate the process of dentin-pulp complex repair. Herein, we sought to explore the ability of Neu5Ac (one form of sialic acid) to influence DPSC osteo-/odontoblastic differentiation via modulating mitogen-activated protein kinase (MAPK) signaling. Methodology. DPSCs were isolated from human third permanent teeth and were grown in vitro. Fluorescent microscopy was used to detect the existence of sialic acid on the DPSC membrane. Following the treatment of different concentrations of Neu5Ac and removing sialic acid from the cell surface by neuraminidase, the osteo-/odontoblastic differentiation of these cells was evaluated via mineralization, alkaline phosphatase, and in vivo assays. In addition, the expression of genes related to osteo-/odontoblastic differentiation and MAPK signaling at different stages of this differentiation process was analyzed in the presence or absence of Neu5Ac. Results. The existence of sialic acid on the DPSC membrane was confirmed by fluorescent microscopy, and the ability of osteo-/odontoblastic differentiation was decreased after removing sialic acid by neuraminidase. Treatment of DPSCs with Neu5Ac (0.1 mM or 1 mM) significantly enhanced their mineralization ability and alkaline phosphatase activity. The expression levels of DMP1, DSPP, BSP, and RUNX2 were also increased. Treatment of nude mice with ManNAc (the prerequisite form of Neu5Ac) also enhanced DPSC mineralization activity in vivo. Furthermore, Neu5Ac treatment enhanced p-ERK expression in DPSCs, while ERK pathway inhibition disrupted the ability of Neu5Ac to enhance the osteo-/odontoblastic differentiation of these cells. Conclusions. Neu5Ac can promote DPSC osteo-/odontoblastic differentiation through a process associated with the modulation of the ERK signaling pathway activity.

Salivary diagnosis of oral cancers by salivary samples: a systematic literature review

The aim of this article is to carry out a systematic analysis of the literature concerning the diagnosis of oral cancers by salivary samples. Different biomarkers, produced by the tumor itself or by its environment, show significant variations in their concentration at the salivary level, correlated or not at the blood or tissue level. After studying 239 articles, we included 36 in this analysis. This allowed us to extract 46 potential molecules for salivary diagnostics. Only 26 demonstrated a good level of evidence. 8 clusters have also been proposed for better specificity and sensitivity. To date, the protocols of the studies carried out do not allow to affirm that one or more biomarkers are effective for a salivary diagnosis of oral cancers. Part of the results contradict or sometimes lack precision. In addition, the studies included here do not have a good methodological quality and do not always take into account other factors influencing the concentrations (systemic diseases, age, sex, tobacco, alcohol, etc.). Additional studies are still necessary, notably with larger groups of patients, representative of the general population and standardization of the protocols for the study and quantification of biomarkers.

ABO Blood Groups and Its Association with Oral Cancer, Oral Potentially Malignant Disorders and Oral Submucous Fibrosis- A Systematic Review and Meta-Analysis

Objective:

The study aimed to evaluate the association between ABO blood groups and oral cancer, other potentially malignant disorders (OPMD), and oral submucous fibrosis (OSMF).

Materials and methods:

A search was conducted in Medline, Cochrane databases, Google Scholar, Scopus, Web of Science and Directory of Open Access Journals (DOAJ) for studies evaluating ABO blood groups as risk factors for oral cancer and OPMD among cases and controls. The PRISMA guidelines were followed for the meta-analysis. Participants included patients with oral cancer, and OPMD diagnosed using histopathologic investigations. Sub-group analysis was conducted to evaluate the association between blood groups and OSMF. Quality was evaluated using the Risk of Bias Assessment tool. Fixed effects model was used to assess the odds ratio for the association.

Results:

There were 1,352, 414, and 299 cases of oral cancer, OPMD, and OSMF and 11,699, 7,382 and 7,307 controls for analysis respectively. Blood group A was significantly associated with both oral cancer (Odds ratio: 1.27 [95% CI, 1.10, 1.47], P= 0.001) and OPMD (Odds ratio: 1.33 [95% CI, 1.01, 1.47], P= 0.04). No association was noted between blood group B and AB with oral cancer, OPMD, and OSMF. Blood group O was significantly associated with lower chances of oral cancer (Odds ratio: 0.81 [95% CI, 0.71, 0.93], P= 0.002).

Conclusion:

Meta-analysis suggests blood group A has a greater risk for developing oral cancer and OPMD. Blood group O was associated with lower chances of oral cancer. No association was noted between ABO blood group system with OSMF.

Estimation of serum pyruvic acid levels in oral squamous cell carcinoma

Introduction:

Cancer cells generally exhibit increased glycolysis for adenosine triphosphate generation (the Warburg effect) due to mitochondrial respiration injury and hypoxia, which are frequently associated with resistance to therapeutic agents. Pyruvic acid is produced as an end product of glycolysis along with lactic acid. At room temperature, lactic acid converts into pyruvic acid as it is chemically unstable.

Aim:

To evaluate the serum pyruvic acid levels in patients with oral squamous cell carcinoma (OSCC).

Materials and Methods:

Thirty clinically and histopathologically confirmed cases of OSCC were included in the study. The cases were staged clinically (tumor–node–metastasis staging) and graded histopathologically (modified Broder's classification). A control group of 30 age-matched individuals with no systemic diseases were selected and the serum levels of pyruvic acid were measured and the absorbance was read using a spectrophotometer at a wavelength of 540 nm. The results were evaluated statistically and discussed.

Results:

Pair-wise comparison of clinical stages and histological grades of OSCC was done using Tukey's multiple post hoc procedure. The increase in mean serum pyruvic acid levels between any two groups and grades was found to be statistically significant respectively (P<0.05).

Conclusion:

Serum pyruvic acid levels gradually increased from individuals without OSCC to individuals with OSCC. Higher levels of serum pyruvic acid were seen with increasing clinical stage and the mean serum pyruvic acid levels were also found to be significantly increasing with advancing histopathological grades of OSCC.

Evaluation of the value of Preoperative Sialic Acid Levels in Diagnosis and Localization of Urothelial Tumors

Objective: To explore SA levels in the serum of urothelial tumor patients and their correlation with clinical pathological features and localization. Materials and Methods: Our research retrospectively collected data from 591 patients with urothelial tumors between July 2014 and April 2018. The SA levels in the serum of urothelial tumor patients and their correlation with clinical pathological features and localization were investigated. Univariate and multivariate logistic regression analyses were further performed to identify independent associations. Results: The levels of SA were significantly associated with the malignant degree (tumor grade and infiltration) of bladder cancer and tumor localization (all p < 0.05). The multivariate logistic regression model showed that SA levels were independently associated with the presence of high-grade urothelial carcinoma (BUC: HR = 1.941, UTUC: HR = 3.820, all p <0.05) and upper urinary tract urothelial carcinoma (HR = 2.047, p < 0.05). Finally, we validated the diagnosis and localization value of SA in an independent cohort from another institutions. Conclusions: Elevated serum SA levels are an independent predictor of high-grade urothelial carcinoma and upper urinary tract urothelial carcinoma, indicating that SA levels may be a potential biomarker for the diagnosis, prognosis and localization of urothelial tumors.

Ratio of Salivary Sialic Acid to Fucose as Tumor Markers in Potentially Malignant Disorders and Oral Cancer

Background:

Lack of noninvasive and economically feasible laboratory investigations in the early detection of cancer is a set-back in the prognosis of oral cancer (OC) patients.

Aims:

The aim of the study was to evaluate the ratio of sialic acid to fucose in salivary samples of OC and oral potentially malignant disorder (OPMD) patients.

Materials and Methods:

A total of 60 participants were selected and divided into three groups based on clinical and histopathological diagnosis: OC patients (n = 20), OPMD patients (n = 20), and healthy patients (n = 20). Unstimulated whole saliva of 1.5 ml was collected from the selected individuals for evaluating the salivary levels of sialic acid and fucose using the biochemical assay.

Results:

The difference in mean salivary sialic acid and fucose among the study groups was statistically significant (P = 0.001); one-way analysis of variance. The mean sialic acid to fucose ratio in the control group, OPMD group, and OC group were 0.34 mg/dl, 0.88 mg/dl, and 0.89 mg/dl, respectively. OC patients had significant elevation in the levels of salivary sialic acid, fucose, and their ratios (P = 0.001, P = 0.001, P = 0.003, respectively); Tukey's post hoc test.

Conclusions:

The ratio of salivary sialic acid to fucose is a predictable tumor marker for the diagnosis of OC. Further investigations are required to evaluate the influence of OC grading on this diagnostic marker.

Verification of Saliva Matrix Metalloproteinase-1 as a Strong Diagnostic Marker of Oral Cavity Cancer

Oral squamous cell carcinoma (OSCC) accounts for >90% of cases of oral cancer, including cancer at the lip and oral cavity and cancer at the oropharynx. Most OSCCs develop from oral potentially malignant disorders (OPMDs), which consist of heterogeneous lesions with different malignant transformation potentials that make early detection of OSCC a challenge. Using a targeted mass spectrometry-based assay to compare multiple candidate proteins, we previously identified matrix metalloproteinase-1 (MMP-1) as one of the most promising salivary OSCC biomarkers. To explore the clinical utility of MMP-1 in OSCC detection, we developed an in-house, sensitive enzyme-linked immunosorbent assay (ELISA) for measuring MMP-1 content, and tested it on saliva samples from 1160 subjects (313 healthy controls, and 578 OPMD and 269 OSCC patients) collected at two medical centers. Salivary MMP-1 levels measured by our in-house ELISA significantly discriminated OSCC patients from non-cancerous groups. A receiver operating characteristic curve analysis showed that MMP-1 was effective in separating non-cancer groups from patients with OSCCs at the oral cavity. Additionally, salivary MMP-1 levels in oral cavity cancer patients were highly correlated with tumor progression (tumor size, lymph node metastasis, and overall stage). Collectively, our results indicate that salivary MMP-1 is an effective biomarker for OSCC that can be sensitively detected using our newly developed ELISA. The newly developed MMP-1 ELISA may be used as a new adjunctive tool to aid in detecting and monitoring OSCC.

Validation of Salivary Markers, IL-1β, IL-8 and Lgals3bp for Detection of Oral Squamous Cell Carcinoma in an Indian Population

Early detection and easier follow-up of oral squamous cell carcinoma (OSCC) would significantly improve the morbidity and mortality associated with it. With newer technologies, it has become possible to validate cancer biomarkers in saliva with high sensitivity and specificity. There is however a need to further validate these biomarkers in cohorts of different ethnic groups. Our objective was to validate previously evaluated salivary biomarkers in Indian population. The study enrolled 117 patients. These were grouped into subcatergories of 31 early (TNMstage I-II) and 27 late-stage OSCC (TNM stage III-IV), 30 PMOD and 29 post-treatment patients. There were 42 control subjects. We evaluated 3 protein markers, IL-1β, IL-8 and LGALS3BP using ELISA, from unstimulated saliva samples. Statistical analysis was done to calculate p-value, ROC, AUC, sensitivity, and specificity. Protein markers IL-1β and IL-8 were significantly elevated (p < 0.05) in OSCC patients. Though the markers could not discriminate PMOD and post-treatment subjects from controls, they proved to be significantly discriminatory between OSCC and controls. Both these markers were especially strong discriminators of late stage OSCC (stage III-IV). IL-1β had the most statistically significant discriminative power (AUC = 0.9017) in late-stage OSCC followed by IL-8 (AUC = 0.7619). Although LGALS3BP was not found to be significantly elevated in late stage OSCC patients, but it was a significant discriminator of early stage OSCC (stage I-II) with p-value = 0.0008 and AUC = 0.7296. These salivary biomarkers have been discovered and validated in other ethnic groups earlier. Hence, the fact that these markers were discriminatory in Indian population too, strengthens the possibility of using these salivary biomarkers as screening tools in different ethnic cohorts. Such trials would potentiate use of a non-invasive tool, like saliva for diagnosis and follow-up of oral cancer.

Saliva and Oral Diseases

Saliva is a fascinating biological fluid which has all the features of a perfect diagnostic tool. In fact, its collection is rapid, simple, and noninvasive. Thanks to several transport mechanisms and its intimate contact with crevicular fluid, saliva contains hundreds of proteins deriving from plasma. Advances in analytical techniques have opened a new era-called "salivaomics"-that investigates the salivary proteome, transcriptome, microRNAs, metabolome, and microbiome. In recent years, researchers have tried to find salivary biomarkers for oral and systemic diseases with various protocols and technologies. The review aspires to provide an overall perspective of salivary biomarkers concerning oral diseases such as lichen planus, oral cancer, blistering diseases, and psoriasis. Saliva has proved to be a promising substrate for the early detection of oral diseases and the evaluation of therapeutic response. However, the wide variation in sampling, processing, and measuring of salivary elements still represents a limit for the application in clinical practice.

Salivary levels of IgE and ECP in patients with recurrent aphthous stomatitis

Background

Recurrent aphthous stomatitis is a common oral mucosa disease, with no specific etiology. Atopy has been implicated in the development of this disease. In this study, the salivary levels of immunoglobulin E (IgE) and eosinophil cationic protein (ECP) were measured as allergy-related biomarkers in patients with aphthous stomatitis.

Material and Methods

In this case-control study, non-stimulated saliva was collected from 85 participants and IgE and ECP were measured. Data were analyzed in SPSS 20 through the Mann-Whitney test, and p<0.05 was considered significant.

Results

The salivary levels of IgE and ECP were 1.11±0.65 Iu/ml and 26.93±6.95 ng/ml in the case group and 0.73±0/39 Iu/ml and 21.97±6.72 ng/ml in the control group. There was a significant difference between the two groups in terms of salivary levels of IgE and ECP (p=0.001).

Conclusions

The results showed that patients with oral aphthous had higher levels of salivary IgE and ECP than controls. Therefore, measurement of these biomarkers may be useful in the initial evaluation of patients with aphthous stomatitis. Key words:Recurrent aphthous stomatitis, saliva, immunoglobulin E, eosinophil cationic protein.

Salivary levels of IgE and ECP in patients with recurrent aphthous stomatitis

Background

Recurrent aphthous stomatitis is a common oral mucosa disease, with no specific etiology. Atopy has been implicated in the development of this disease. In this study, the salivary levels of immunoglobulin E (IgE) and eosinophil cationic protein (ECP) were measured as allergy-related biomarkers in patients with aphthous stomatitis.

Material and Methods

In this case-control study, non-stimulated saliva was collected from 85 participants and IgE and ECP were measured. Data were analyzed in SPSS 20 through the Mann-Whitney test, and p<0.05 was considered significant.

Results

The salivary levels of IgE and ECP were 1.11±0.65 Iu/ml and 26.93±6.95 ng/ml in the case group and 0.73±0/39 Iu/ml and 21.97±6.72 ng/ml in the control group. There was a significant difference between the two groups in terms of salivary levels of IgE and ECP (p=0.001).

Conclusions

The results showed that patients with oral aphthous had higher levels of salivary IgE and ECP than controls. Therefore, measurement of these biomarkers may be useful in the initial evaluation of patients with aphthous stomatitis.

Key words:Recurrent aphthous stomatitis, saliva, immunoglobulin E, eosinophil cationic protein.

Estimation of serum sialic acid in oral submucous fibrosis and oral squamous cell carcinoma

Background and Objectives:

Sialic acid (SA) N-acetyl neuraminic acid is a negatively charged 9-carbon monosaccharide, commonly attached to the nonreducing residues of carbohydrate chains of glycoconjugates by glycosidic linkage. SA is widely distributed in glycoproteins (GPs) of cell membrane. The alterations in GPs start at an early stage of tumorigenesis. Hence, the aim of the present study is to evaluate the levels of serum SA in normal individuals, in patients with oral submucous fibrosis (OSMF), oral squamous cell carcinoma (OSCC), and compare the levels with respect to the clinical staging and histological grading.

Materials and Methods:

A total of 90 individuals were selected for the purpose of the study. Thirty cases of clinically diagnosed and histopathologically confirmed cases of OSMF and OSCC each were included. A control group of 30 age and gender-matched individuals with no systemic diseases were selected. Serum levels of SA were measured based on the reaction between SA and ninhydrin. The absorbance was read using a spectrophotometer.

Results:

Serum SA levels were significantly increased in OSMF, OSCC patients as compared with controls. When multiple comparison was done using post hoc Tukey test, there is a statistically significant difference between clinical staging and histopathological grading of OSMF and OSCC (P < 0.05).

Conclusion:

The serum SA levels in OSMF and OSCC patients were increased as compared with controls suggesting that, it can be used as a reliable biomarker for prognostic evaluation, and also give a clue about the amount of tumor burden in the individual.

Glycoproteomic identification of novel plasma biomarkers for oral cancer

Oral cancer with high incidence rates is occurring in many countries including in India, Pakistan, Bangladesh, Sri Lanka and Taiwan. Smoking, alcoholism, and betel nut chewing are considered to be the main risk factors for oral cancer. Further, deaths from oral cancer have increased year by year. Although several oral cancer-associated biomarkers have been reported, very few useful biomarkers have been applied for early diagnosis. Therefore, the investigation of oral cancer-specific biomarkers is urgently needed. We previously investigated N-glycomes of oral cancer cells and patient plasma. We found that both mRNA levels of FUT8 and core-fucosylated glycoproteins increase in cases of oral cancer relative to normal cases. In this study we aim to discover novel core-fucosylated glycoprotein biomarkers for oral cancer diagnosis with glycoproteomic approaches. First, forty plasma samples obtained from the Human Bioinformation Bank of NCKUH were subjected to AAL (Aleuria aurantia lectin) affinity chromatography. Core-fucosylated proteins were collected and applied for LC-MS/MS followed by electrophoresis. Fourteen proteins were identified, and expression levels of proteins in plasma were verified by western blot. Expression levels of some glycoproteins were elevated in the oral cancer group, including ceruloplasmin, haptoglobin, and leucin-rich alpha-2-glycoprotein 1 (LRG1). However, levels of some glycoproteins decreased in the cancer group, including apolipoprotein A-I (apo A-I) and apolipoprotein A-IV (apo A-IV). Via ELISA analysis, we found that apo A-IV and apo A-IV/total protein ratios were decreased in plasma accompanied with cancer stages. The LRG1/total protein ratio was found to increase while plasma levels of LRG1 were not found to differ between the oral cancer plasma and normal groups. An ROC curve analysis reveals strong diagnosis performance when combining apo A-IV levels and LRG1/total protein ratios. Taken together, apo A-IV and LRG1, given their strong performance in detecting oral cancer, can serve as useful biomarkers and may be used as a useful tool for oral cancer screening and early diagnosis.

Elevated Serum Sialic Acid Levels Predict Prostate Cancer As Well As Bone Metastases

Objective: To evaluate the value of serum sialic acid (SA) in diagnosis of benign prostatic hyperplasia (BPH), prostate cancer (PCa), and bone metastases in PCa patients. Materials and Methods: Data from 540 patients who were newly diagnosed with PCa or BPH between November 2014 and March 2018 were retrospectively collected and analyzed. Pretreatment SA levels were compared across various groups, then, associations between SA levels and clinic parameters of patients were analyzed as well. Univariate and multivariate logistic regression analyses were further used to identify independent associations. Results: The mean SA levels in patients with PCa were significantly higher than with BPH (p = 0.013). Furthermore, PCa patients with bone metastases showed elevated SA levels compared with PCa without bone metastases (p < 0.001). A multivariate logistic regression model showed that: SA level > 52.35 mg/dL was identified to be independently associated with the diagnosis of PCa (HR = 1.645, p = 0.036), and SA level > 59 mg/dL was identified to be independent association with the presence of bone metastases in PCa patients (HR = 6.421, p = 0.012). Conclusions: Elevated SA level is an independent predictor of prostate cancer as well as its bone metastases. Therefore, SA level may be a promising diagnostic and prognostic biomarker for prostate cancer and bone metastases.

Potential role of nuclear magnetic resonance spectroscopy to identify salivary metabolite alterations in patients with head and neck cancer

The analysis of the salivary metabolomic profile may offer an early phase approach to assess the changes associated with a wide range of diseases including head and neck cancer. The aim of the present study was to investigate the potential of nuclear magnetic resonance (NMR) spectroscopy for detecting the salivary metabolic changes associated with head and neck squamous cell carcinoma (HNSCC). Unstimulated whole-mouth saliva samples collected from HNSCC patients (primary tumour was located either in the larynx or in the oral cavity) and healthy controls were analysed by ¹H-NMR spectroscopy. Reliably identified salivary metabolites were quantified and the determined concentration values were compared group-wise using a Mann-Whitney U-test. Multivariate discrimination function analysis (DFA) was conducted to identify such a combination of metabolites, when considered together, that gives maximum discrimination between the groups. HNSCC patients exhibited significantly increased concentrations of 1,2-propanediol (P=0.032) and fucose (P=0.003), while proline levels were significantly decreased (P=0.043). In the DFA model, the most powerful discrimination was achieved when fucose, glycine, methanol and proline were considered as combined biomarkers, resulting in a correct classification rate of 92.1%, sensitivity of 87.5% and specificity of 93.3%. To conclude, NMR spectrometric analysis was revealed to be a feasible approach to study the metabolome of saliva that is sensitive to metabolic changes in HNSCC and straightforward to collect in a non-invasive manner. Salivary fucose was of particular interest and therefore, controlled longitudinal studies are required to assess its clinical relevance as a diagnostic biomarker in HNSCC.

[Advances in salivary protein glycosylation and its relationship with systemic and oral diseases]

Protein glycosylation is one of the most important protein post-translational modifications that can affect life activities by endowing the protein with various structural and functional features. Saliva is an easy-to-obtain, noninvasive body fluid that contains components originating from serum, gingival crevicular fluid, and oropharyngeal mucosae. In recent years, understanding of saliva has been constantly updated with the developments in related research. Studies have shown that salivary proteins can be used as diagnostic markers for certain diseases, and changes of protein glycosylation in saliva are generally considered to be related to many diseases. In this review, salivary protein glycosylation and its relationship with systemic and oral diseases were discussed.

Evaluation of Total and Lipid Bound Sialic Acid in Serum in Oral Leukoplakia

INTRODUCTION

Oral cancer has become the most common cause of cancer related mortality which may be preceded by oral potentially malignant disorders. Altered glycosylation of glycoconjugates, such as sialic acid are one of the most important molecular changes accompanied during malignant transformation in precancerous lesions like Oral Leukoplakia (OL), and correlating them histopathologically with grades of epithelial dysplasia which will serve clinical significance.

AIM

The aim of this study was to evaluate the significance of serum Total Sialic Acid (TSA) and serum Lipid Bound Sialic Acid (LSA) as a prognostic serum marker in Oral Leukoplakia.

MATERIALS AND METHODS

Blood samples were collected from 30 patients diagnosed with OL and 30 healthy controls. Serum sialic acid (total and lipid bound) levels were measured using spectrophotometer. Tissue samples were histopathologically typed and were graded for epithelial dysplasia. Data were analysed using Independent t-test and Kruskal Wallis method.

RESULTS

Serum levels of both total and lipid bound sialic acids were found to be increased in OL when compared to healthy controls. The mean TSA levels among those in the OL group (45.3±4.2) were significantly greater than healthy controls (29±2.2). On multiple comparison the highest mean TSA level was found in severe OL compared to moderate and mild OL (p<0.05). The mean levels of LSA were found to be statistically non-significant between the groups.

CONCLUSION

The present study showed that the serum levels of both TSA and LSA were found to be increased in OL when compared to apparently healthy controls. We also found that with increasing grades of epithelial dysplasia TSA levels were found to be gradually increasing which was significant for this study serving as an early indicator for the detection of malignant transformation in OL.

Salivary Sialic Acid Levels in Smokeless Tobacco Users

BACKGROUND

Smokeless tobacco chewing is one of the known risk factors for oral cancer. It is consumed widely by residents of southeastern Iran.

OBJECTIVES

In this study, salivary free and total sialic acid, and total protein were compared in paan consumers and non-consumers.

PATIENTS AND METHODS

In this cross-sectional study, unstimulated saliva of 94 subjects (44 paan consumers and 50 non-consumers) who were referred to the oral medicine department of the dentistry school of Zahedan were collected. Salivary free and total sialic acid, and total protein concentration were measured by standard biochemical methods, and the obtained data were analyzed using SPSS 20 through the non-parametric Mann-Whitney test.

RESULTS

The concentration of salivary free sialic acid (23.21 ± 18.98 mg/L) was significantly increased in paan consumers. The concentration of salivary Total sialic acid (TSA) (39.57 ± 26.58 mg/L) and total protein (0.77 ± 0.81 mg/mL) showed increases in paan consumers, however, the results were not statistically significant.

CONCLUSIONS

Salivary free and total sialic acid, and total protein were higher in the paan consumers compared to non-consumers. Due to the carcinogenic effect of smokeless tobacco, measurement of these parameters in saliva may be useful in early detection of oral cancer.