Salivary RNA signatures in oral cancer detection

Polyamines in Dysbiotic Oral Conditions of Older Adults: A Scoping Review

Polyamines modulate cellular proliferation and function. Their dysregulation results in inflammatory and oncological repercussions. This study aims to map the current literature and provide an overview of polyamines in dysbiotic oral conditions among older adults. English publications indexed in MEDLINE, Scopus, and Web of Science from January 2000 to May 2024 were screened. Eligibility criteria included clinical and laboratory studies using samples from adults aged 65 or above. This scoping review identified 2725 publications and included 19 publications. Ten studies detected that older adults with oral carcinoma had increased levels of polyamines such as spermidine in saliva and tumour-affected tissues. Eight studies reported older adults suffering from periodontal infection had increased levels of polyamines such as putrescine in saliva, gingival crevicular fluid, and biofilm from the gingival crevice. Two studies showed polyamine levels could reflect the success of periodontal therapy. Three studies found older adults with halitosis had increased levels of polyamines such as cadaverine in saliva and tongue biofilm. Polyamines were suggested as biomarkers for these oral conditions. In conclusion, certain polyamine levels are elevated in older adults with oral cancer, periodontal infections, and halitosis. Polyamines may be used as a simple and non-invasive tool to detect dysbiotic oral conditions and monitor treatment progress in older adults (Open Science Framework registration).

Exosomal miR-151-3p in saliva: A potential non-invasive marker for gastric cancer diagnosis and prognosis modulated by Sijunzi decoction (SJZD) in mice

Gastric cancer (GC) is one of the most prominent malignancies that originate in the epithelial cells of the gastric mucosa and is one of the main causes of cancer-related mortality worldwide. New circulating biomarkers of exosomal RNA might have great potential for non-invasive early prognosis of GC. Sijunzi Decoction (SJZD) is a typical representative formula of the method of benefiting Qi and strengthening the spleen in Traditional Chinese Medicine (TCM). However, the effects and mechanism of SJZD in treating GC remain unclear. This study looked for biomarkers of exosomal RNA for early prognosis of GC, and explored the mechanism of SJZD in treating GC. A gastric cancer model with spleen deficiency syndrome was established in nude mice, and the curative effects of SJZD were investigated. Differentially expressed miRNAs in plasma and saliva exosomes were sequenced and analyzed. Potential target genes of these miRNAs were predicted and applied for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway enrichment annotation. Overlapping miRNAs in saliva and plasma samples were analyzed, and qRT-PCR was performed for verification. miR-151a-3p was selected, and qRT-PCR further determined that miR-151a-3p was downregulated in saliva and plasma exosomes from the SJZD group. The intersected miR-151a-3p target genes were predicted and enriched in the extrinsic apoptotic signaling pathways. SJZD significantly ameliorates gastric cancer with spleen deficiency syndrome in mouse models, and exosomal miRNAs, particularly miR-151-3p, might be modulated by SJZD in plasma and saliva. The exosomal miR-151-3p in saliva may serve as a non-invasive potential marker for gastric cancer diagnosis and prognosis.

Review Insights on Salivary Proteomics Biomarkers in Oral Cancer Detection and Diagnosis

Early detection is crucial for the treatment and prognosis of oral cancer, a potentially lethal condition. Tumor markers are abnormal biological byproducts produced by malignant cells that may be found and analyzed in a variety of bodily fluids, including saliva. Early detection and appropriate treatment can increase cure rates to 80-90% and considerably improve quality of life by reducing the need for costly, incapacitating medicines. Salivary diagnostics has drawn the interest of many researchers and has been proven to be an effective tool for both medication monitoring and the diagnosis of several systemic diseases. Since researchers are now searching for biomarkers in saliva, an accessible bodily fluid, for noninvasive diagnosis of oral cancer, measuring tumor markers in saliva is an interesting alternative to blood testing for early identification, post-treatment monitoring, and monitoring high-risk lesions. New molecular markers for oral cancer detection, treatment, and prognosis have been found as a result of developments in the fields of molecular biology and salivary proteomics. The numerous salivary tumor biomarkers and how they relate to oral cancer and pre-cancer are covered in this article. We are optimistic that salivary protein biomarkers may one day be discovered for the clinical detection of oral cancer because of the rapid advancement of proteomic technology.

Advances in the Diagnosis, Monitoring, and Progression of Oral Cancer through Saliva: An Update

The early detection of cancer, and in particular oral cancer, has been a priority objective of study in recent years. Saliva has been proposed as an easy-to-obtain means of providing the necessary information to diagnose malignant lesions in the oral cavity, since it can be obtained very easily and completely noninvasively. There are a number of molecules, known as biomarkers, which may be involved in the malignant transformation of oral lesions, and which have different natures. The involvement of proteins (“proteomics”), metabolites (“metabolomics”), and even certain genes in the structural changes of altered tissue has been investigated in order to establish validated parameters for the early diagnosis of oral cancer. In addition, the development of new analytical assay methods that can reduce costs and obtain better results in terms of sensitivity and specificity has been a key point in recent research in this field. Even though there are numerous biomarkers with results showing high sensitivity and specificity, there is still a need for more studies, with a larger sample and with analytical methods that can constitute a real advance in time and cost. Although salivary biomarkers are a promising new diagnostic tool for oral cancer, for the moment they do not replace biopsy as the “gold standard”.

The New Era of Salivaomics in Dentistry: Frontiers and Facts in the Early Diagnosis and Prevention of Oral Diseases and Cancer

Nowadays, with the development of new and highly sensitive, blood is not the only medium of choice for the diagnosis of several diseases and pathological conditions. Saliva is now considered a safe and non-invasive sample to study oral and systemic diseases, showing great diagnostic potential. According to several recent studies, saliva has emerged as an emerging biofluid for the early diagnosis of several diseases, indicated as a mirror of oral and systemic health and a valuable source of clinically relevant information. Indeed, several studies have observed that saliva is useful for detecting and diagnosing malignant tumours, human immunodeficiency virus, heart disease, and autoimmune diseases. The growing realisation that saliva is an inexhaustible source of information has led to the coining of the term ‘Salivaomics’, which includes five “omics” in connection with the main constituents of saliva: genome and epigenome, transcriptomics, metabolomics, lipidomics, proteomics and microbiota. All those may be changed by disease state, so they offer significant advantages in the early diagnosis and prognosis of oral diseases. The aim of the present review isto update and highlight the new frontiers of salivaomics in diagnosing and managing oral disorders, such as periodontitis, premalignant disorders, and oral squamous cell carcinoma (OSCC).

Diagnostic Accuracy of Salivary Biomarkers in Detecting Early Oral Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

BACKGROUND

Biopsy is the gold standard for oral squamous cell carcinoma (OSCC) diagnosis. Salivary biomarkers provide promising complementary alternative diagnostic adjunct for its simple non- invasive collection and technique and to screen large population.

OBJECTIVE

To summarize and compare the existing evidence on diagnostic accuracy of salivary biomarkers with their estimation method in detecting early oral squamous cell carcinoma.

METHODS

The review protocol is registered under PROSPERO(CRD42021225704). PubMed, Google Scholar, EBSCOhost were searched from 2000 to 2020 to identify the screening potential of eight salivary biomarkers: mRNA, miRNA, DUSP100, s100P, IL-8, IL-1B, TNF-a and MMP-9. True-positive, false-positive, true-negative, false-negative, sensitivity, specificity values were extracted or calculated if not present for each study. Quality of selected studies was evaluated based on QUADAS 2 tool. Meta-analysis was performed using a bivariate model parameter for the sensitivity and specificity and summary points, summary receiver operating curve (SROC), confidence region, and prediction region were calculated.

RESULTS

Eighteen studies were included for qualitative synthesis and out of that 13 for meta-analysis. Sensitivity and specificity were calculated with AUC. For mRNA it was 91% and 90% with 0.96 AUC, miRNA had 91% and 91% with 0.95 AUC for PCR. IL-1B had 46% and 60% with 0.61 AUC, S100p had 45% and 90% with 0.57 AUC for ELISA. IL-8 had 54% and 74% for ELISA and 89% and 90% for PCR with 0.79 AUC and DUSP1 had 32% and 87% for ELISA and 76% and 83% for PCR with 0.83 AUC respectively.

CONCLUSION

Early detection of OSCC was best achieved by screening for salivary mRNA and miRNA estimated by PCR. Further investigation is required into salivary RNA as novel biomarkers and these salivary biomarkers may be potentially used for non-invasive diagnosis of early OSCC.

Application of liquid biopsy as multi-functional biomarkers in head and neck cancer

Head and neck squamous cell carcinoma (HNSCC) is a molecularly heterogeneous disease, with a 5-year survival rate that still hovers at ~60% despite recent advancements. The advanced stage upon diagnosis, limited success with effective targeted therapy and lack of reliable biomarkers are among the key factors underlying the marginally improved survival rates over the decades. Prevention, early detection and biomarker-driven treatment adaptation are crucial for timely interventions and improved clinical outcomes. Liquid biopsy, analysis of tumour-specific biomarkers circulating in bodily fluids, is a rapidly evolving field that may play a striking role in optimising patient care. In recent years, significant progress has been made towards advancing liquid biopsies for non-invasive early cancer detection, prognosis, treatment adaptation, monitoring of residual disease and surveillance of recurrence. While these emerging technologies have immense potential to improve patient survival, numerous methodological and biological limitations must be overcome before their implementation into clinical practice. This review outlines the current state of knowledge on various types of liquid biopsies in HNSCC, and their potential applications for diagnosis, prognosis, grading treatment response and post-treatment surveillance. It also discusses challenges associated with the clinical applicability of liquid biopsies and prospects of the optimised approaches in the management of HNSCC.

Salivaomics for Oral Cancer Detection: An Insight

Early detection is very crucial for successful management of oral cancer or any disease as such. Oral squamous cell carcinoma (OSCC) accounts for nearly 90% of malignancy of oral cavity. In the field of cancer research, there is always an ongoing quest for newer methods to lower the morbidity and mortality associated with OSCC. Saliva, a readily available noninvasive biofluid with constant contact with oral cancer lesion, offers an appealing alternative to serum and tissue testing. This review throws light on incorporation of newer technologies for harnessing the saliva to its fullest potential with increased specificity and sensitivity toward identification of cancer-specific molecular signatures for the development of point-of-care applications that could be used at the clinical setting.

Salivary miR-30c-5p as Potential Biomarker for Detection of Oral Squamous Cell Carcinoma

The levels of different classes of extracellular RNAs (exRNAs) remain stable in bodily fluids. The detection of either enriched or depleted specific subsets of salivary microRNAs (miRNAs) has the potential to serve as a non-invasive approach for biomarker development. Thus, salivary miRNAs have emerged as a promising molecular tool for early diagnosis and screening of oral squamous cell carcinoma (OSCC). Total RNA was extracted from saliva supernatant of 33 OSCC patients and 12 controls (discovery set), and the differential expression of 8 cancer-related miRNAs was detected by TaqMan assay. Among the screened miRNAs, miR-30c-5p (p < 0.04) was significantly decreased in OSCC saliva. The same transcriptional behavior of miR30c-5p was observed in an additional validation set. miR-30c-5p showed a significant statistical difference between cases and controls with areas under the curve (AUC) of 0.82 (95% CI: 0.71–0.89). The sensitivity and the specificity of miR-30c-5p were 86% and 74%, respectively. The target identification analysis revealed enrichment of miR-30c-5p targets in p53 and Wnt signaling pathways in OSCC. Additionally, the miR-30c-5p targets had clinical significance related to overall survival. In conclusion, these findings show that downregulated miR-30c-5p has the potential to serve as a novel, non-invasive biomarker for early OSCC detection.

Comparative analysis of nucleomorphometric parameters in methyl green-pyronin-stained sections of oral epithelial dysplasia, oral submucous fibrosis and oral squamous cell carcinoma

Context:

The diagnosis and grading of epithelial dysplasia is based on a combination of architectural and cytological changes. A gradual increase in quantitative DNA aberrations has been found to correlate with increasing degree of dysplasia in oral mucous membranes.

Aims:

The aim of this study is to assess nuclear parameters in potentially malignant and malignant lesions of the oral cavity and to assess cytomorphometric changes in the nucleus and nucleolus in oral epithelial dysplasia (OED), oral submucous fibrosis (OSMF), oral squamous cell carcinoma (OSCC) and normal oral mucosa using methyl green-pyronin staining to determine its suitability for detecting potentially malignant lesions and the stage of carcinogenesis.

Methods:

Forty-five archival sections of OED, OSMF and OSCC and 5 cases of normal oral mucosa as the control group were stained according to methyl green-pyronin-staining protocol. Cytomorphometric parameters such as nuclear diameter, nucleolar diameter, number of nucleoli and cytoplasmic RNA were assessed.

Statistical Analysis Used:

The study was subjected to statistical analysis to evaluate the association between morphometric parameters using analysis of variance test, followed by Bonferroni's post hoc analysis.

Results:

A progressive increase in the nuclear parameters as well as cytoplasmic RNA content was observed between normal mucosa through dysplasia and OSMF to OSCC.

Conclusion:

This study serves as an effective diagnostic aid in assessing nuclear parameters in potentially malignant and malignant epithelial lesions affecting oral cavity.

A Clinical Study on Detection of Dysplastic Cells Through Saliva

Saliva is an ideal tool for liquid biopsy as it is noninvasive, easily collected, and easily transported. Saliva is used to detect various biomarkers in oral cancer patients, but none used for detecting salivary dysplastic cells in potentially malignant and malignant disorders. To detect dysplastic cells from saliva in oral cancer and potentially malignant patients and compare with wedge biopsy. All potentially malignant and malignant cases of oral cavity were included in this study. In these patients, unstimulated saliva was collected and centrifuged. The concentrated salivary substrate was stained by Haematoxylin and Eosin (H&E) stain, PAP (Papanicolaou) method and May Grunwald Giemsa stain (MGG) and analyzed. Wedge biopsy was performed from the representative area in the oral cavity and compared with salivary cells. In our study, out of 24 patients, 16 cases were malignant, and 8 were potentially malignant. 12 patients were found to be positive for atypical cells, 10 patients were found to be positive for dysplastic cells and atypical cells, and two patients were negative for atypical cells/dysplastic cells. In 10 patients who were positive for dysplastic cells, all were diagnosed histologically as malignancies (P = 0.001). The two patients who were negative for atypical cells/dysplastic cells showed precursor epithelial lesion with hyperplasia in the biopsy. Few neutrophils were found in 15 patients and increased in 9 patients (P = 0.039). Saliva is readily available, and can be collected noninvasively for detecting dysplastic cells.

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.

The expression of melanoma-associated antigen A (MAGE-A) in oral squamous cell carcinoma: an evaluation of the significance for tumor prognosis

OBJECTIVES

Melanoma-associated antigens A had been detected repeatedly in oral squamous cell carcinoma, but not in healthy mucosa. Additionally, patients with MAGE-A expressing cancers are regarded to have a worse survival prognosis, so that MAGE-A are supposed to be part of carcinogenesis. Which role these antigens fulfill within OSCC is still, up today, largely unknown. This study examines the hypothesis that MAGE-A is being produced in OSCC but not in mucosa tissue and if MAGE-A has any correlation to clinical patient's parameters like tumor size, lymph node metastasis, distant metastasis, overall survival, and recurrence.

MATERIALS AND METHODS

For this purpose, 50 tumor samples and 39 mucosa samples were analyzed by means of PCR and immunohistochemical staining with the antibody 6C1.

RESULTS

Forty of 41 stained tumor samples showed a positive antibody reaction with a maximum staining rate of 53%. Sixteen mucosa samples showed a mild positive reaction. The PCR revealed a linear expression pattern of MAGE-A in which the genes are proportionally expressed in OSCC. We did not find any relationship between MAGE-A and tumor size, overall survival, or recurrence. There was also no connection between MAGE-A and tumor parameters Hif-1 and LDH. Their expression was detected tendentially in tumors with higher staging, advanced lymph node metastasis, and rising age of the patients. The genes MAGE-A3+6 and MAGE-A4 had a statistically significant correlation with lymph node metastasis (p = 0.007 and p = 0.004). Patients got distant metastasis and influence of MAGE-A on metastatic behavior could not be verified. The genes MAGE-A3 and -A4 are consequently qualified as tumor markers in the field of diagnosis and follow-up of OSCC.

CONCLUSIONS AND CLINICAL RELEVANCE

Two genes have great potential as target proteins in immunotherapy. The genes MAGE-A3+6 and MAGE-A4 had a statistically significant correlation with lymph node metastasis.

Nanoparticle-based assay for detection of S100P mRNA using surface-enhanced Raman spectroscopy

The focus of this work is toward the development of a point-of-care (POC) handheld technology for the noninvasive early detection of salivary biomarkers. The initial of focus was the detection and quantification of S100 calcium-binding protein P (S100P) mRNA found in whole saliva for use as a potential biomarker for oral cancer. Specifically, a surface-enhanced Raman spectroscopy (SERS)-based approach and assay were designed, developed, and tested for sensitive and rapid detection of S100P mRNA. Gold nanoparticles (AuNPs) were conjugated with oligonucleotides and malachite green isothiocyanate was then used as a Raman reporter molecule. The hybridization of S100P target to DNA-conjugated AuNPs in sandwich assay format in both free solution and a vertical flow chip (VFC) was confirmed using a handheld SERS system. The detection limit of the SERS-based assay in free solution was determined to be 1.1 nM, whereas on the VFC the detection limit was observed to be 10 nM. SERS-based VFCs were also used to quantify the S100P mRNA from saliva samples of oral cancer patients and a healthy group. The result indicated that the amount of S100P mRNA detected for the oral cancer patients is three times higher than that of a healthy group.

Dysregulated Phosphate Metabolism, Periodontal Disease, and Cancer: Possible Global Health Implications

An association between periodontal disease and cancer has been established in recent studies, but no common etiology has been identified in the hopes of reducing the global burden of these non-communicable diseases. This perspective article hypothesizes that the determinant mediating the association of periodontal disease with cancer is dysregulated phosphate metabolism. Phosphate, an essential dietary micronutrient, is dysregulated in chronic kidney disease, and both cancer and periodontal disease are associated with chronic kidney disease. Reviewed evidence includes the association between phosphate toxicity and cancer development, and the association between periodontal disease and chronic kidney disease-mineral and bone disorder includes conditions such as ectopic calcification and bone resorption, which may be indirectly related to periodontal disease. Dental calculus in periodontal disease contains calcium phosphate crystals that are deposited from excess calcium and phosphate in saliva. Alveolar bone resorption may be linked systemically to release of parathyroid hormone in response to hypocalcemia induced by hyperphosphatemia. More research is needed to examine the role of dysregulated phosphate metabolism in periodontal disease.

Uncovering the potential of CD44v/SYNE1/miR34a axis in salivary fluids of oral cancer patients

OBJECTIVES

Late-stage diagnosis is one of the major confounders for poor prognosis of patients with oral cancer owing to lack of a biomarker to diagnose this disease at an early stage. Moreover, till date, invasive biopsies are the only option to assess disease occurrence and progression in this malignancy. Thus, this study aims to identify and assess potential salivary markers in OSCC patients in order to open newer avenues in the field of non-invasive biopsies.

METHODOLOGY

Bioinformatic-based analysis was performed to identify potential biomarkers that could be assessed in OSCC patients. The expression patterns of CD44v and its genetic and epigenetic modulators were assessed in saliva of OSCC patients, leukoplakia, and controls using real-time and methylation-specific PCR. Statistical analysis was conducted to understand the significance of these markers in terms of their clinical relevance.

RESULTS

CD44v/SYNE1/miR34a axis was identified using bioinformatic analysis, and the expression profile of these markers was assessed in saliva of OSCC patients. CD44v6 and CD44v10 demonstrated a significantly increased expression, whereas SYNE1 and miR34a depicted a significantly decreased expression in OSCC patients. Statistical analysis suggested a probable role of CD44v6, SYNE1, and miR34a in early stages of the malignancy, whereas a strong association was observed between CD44v6, CD44v10, and miR34a expression with locoregional aggressiveness and histopathological conditions.

CONCLUSION

Collectively, these findings suggested a plausible role of CD44v/SYNE1/miR34a axis as non-invasive salivary biomarkers to diagnose this disease at an early stage and predict the early onset of metastasis.