Improving accuracy of RNA-based diagnosis and prognosis of oral cancer by using noninvasive methods

Salivary miRNAs as auxiliary liquid biopsy biomarkers for diagnosis in patients with oropharyngeal squamous cell carcinoma: a systematic review and meta-analysis

Objective: The healthcare system needs a novel approach to improve and diagnose early oropharyngeal squamous cell carcinoma against its low survival rate. We conduct a systematic review and a comprehensive meta-analysis for the diagnostic role of blood and salivary microRNAs (miRNAs). Methods: An unbiased and thorough literature search in PubMed yielded appropriate data from qualified articles regarding different miRNA biomarkers, method of extraction, research location, and year of publication. Stata was used to calculate the sensitivity, specificity, diagnostic odds ratio, and summary receiver operating characteristic curve. Results: We included 9 studies with 399 qualified oropharyngeal squamous cell carcinoma patients, which yielded a high diagnostic accuracy of blood miRNAs in combination with salivary miRNAs with a sensitivity of 0.70 (p < 0.001), specificity of 0.75 (p = 0.26), diagnostic odds ratio of 7, and an area under the curve of 0.78. Conclusion: Combined blood- and saliva-derived miRNAs demonstrated a high diagnostic accuracy in detecting oropharyngeal squamous cell carcinoma. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024509424.

MiRNAs as non-invasive biomarkers in the serum of Oral Squamous Cell Carcinoma (OSCC) and Oral Potentially Malignant Disorder (OPMD) patients

OBJECTIVE

Cell-free microRNAs have shown differential levels in the serum of individuals under disease conditions suggesting its potential to act as biomarkers. A population specific miRNA signature in oral cancer is reported in different studies. We aim to identify a set of serum specific miRNAs that may differentiate oral cancer, oral pre-malignant conditions from the healthy individuals.

DESIGN

We investigated the levels of 24 miRNAs in the serum of 47 Oral squamous cell carcinoma (OSCC) patients, 20 patients with Oral potentially malignant disorders (OPMD) and 42 healthy controls from Eastern India. Small RNAs were isolated from serum samples followed by cDNA synthesis. Levels of miRNAs were determined using qRT-PCR. The sources of serum specific miRNAs were evaluated using GTEx-RNAseq and TCGA-HNSCC database.

RESULTS

Five miRNAs, miR-483-5p, miR-31-5p, Let-7b-5p, miR-486-5p and miR-30e-5p showed significant elevation in OSCC patients. An Elastic-Net model with 4 miRNAs classified OSCC from healthy controls with 80 % sensitivity, 64.3 % specificity, and 72.4 % accuracy. Mir-483-5p and miR-31-5p was significantly overexpressed in OSCC tissues as well as significantly higher in the serum of Leukoplakia and Verrucous carcinoma patients suggesting their potential as early disease markers. MiR-483-5p showed a consistent elevated level in the serum/plasma of oral cancer patients across different population and was found to be tumour specific while, the rest of the miRNAs showed variable results across different studies.

CONCLUSIONS

Our study suggested that the serum miRNAs in oral cancer and pre-malignant disorder conditions can be used as a non-invasive marker for screening of these oral conditions.

Transcriptomic analysis predicts the risk of progression of premalignant lesions in human tongue

The 5-year survival rate for patients with oral squamous cell carcinomas (SCC), including tongue SCC, has not significantly improved over the last several decades. Oral potentially malignant disorders (OPMD), including oral dysplasias, are oral epithelial disorders that can develop into oral SCCs. To identify molecular characteristics that might predict conversion of OPMDs to SCCs and guide treatment plans, we performed global transcriptomic analysis of human tongue OPMD (n = 9) and tongue SCC (n = 11) samples with paired normal margin tissue from patients treated at Weill Cornell Medicine. Compared to margin tissue, SCCs showed more transcript changes than OPMDs. OPMDs and SCCs shared some altered transcripts, but these changes were generally greater in SCCs than OPMDs. Both OPMDs and SCCs showed altered signaling pathways related to cell migration, basement membrane disruption, and metastasis. We suggest that OPMDs are on the path toward malignant transformation. Based on patterns of gene expression, both OPMD and tongue SCC samples can be categorized into subclasses (mesenchymal, classical, basal, and atypical) similar to those seen in human head and neck SCC (HNSCC). These subclasses of OPMDs have the potential to be used to stratify patient prognoses and therapeutic options for tongue OPMDs. Lastly, we identified a gene set (ELF5; RPTN; IGSF10; CRMP1; HTR3A) whose transcript changes have the power to classify OPMDs and SCCs and developed a Firth logistic regression model using the changes in these transcripts relative to paired normal tissue to validate pathological diagnosis and potentially predict the likelihood of an OPMD developing into SCC, as data sets become available.

Status and Determinants of Early Detection of Oral Premalignant and Malignant Lesions in India

It has been over four decades since the launch of the National Cancer Control Programme in India, yet the cancer screening rates for oral cancer remain unremarkable. Moreover, India is bracing a large burden of oral cancer with poor survival rates. An effective public health programme implementation relies on a multitude of factors related to cost-effective evidence-based interventions, the healthcare delivery system, public health human resource management, community behaviour, partnership with stakeholders, identifying opportunities and political commitment. In this context, we discuss the various challenges in the early detection of oral premalignant and malignant lesions and potential solutions.

Multiple microRNA signature panel as promising potential for diagnosis and prognosis of head and neck cancer

MicroRNAs are small non-coding RNA that regulate gene expressions of human body. To date, numerous studies have reported that microRNAs possess great diagnostic and prognostic power in head and neck cancer and had governed a lot of attention. The factor for the successfulness of miRNAs in these aspects is due to cancer being fundamentally tied to genetic changes, which are regulated by these miRNAs. Head and neck cancer, leading the world record for cancer as number sixth, is caused by multiple risk factors such as tobacco consumption, alcohol consumption, dietary factors, ethnicity, family history, and human papilloma virus. It derives at locations such as oral cavity, pharynx, larynx, paranasal sinus and salivary gland and have high rate of mortality with high recurrence rate. Besides, head and neck cancer is also usually having poor prognosis due to its asymptomatic nature. However, this diagnostic and prognostic power can be further improved by using multiple panels of miRNA as a signature or even combined with TNM staging system to obtain even more remarkable results. This is due to multiple factors such as tumour heterogeneity and components of the tumour which may affect the composition of miRNAs. This review covers the examples of such miRNA signatures, compare their diagnostic and prognostic powers, discuss some controversial roles of unreported miRNAs, and the molecular mechanisms of the miRNAs in gene targeting and pathways.

Gut/Oral Bacteria Variability May Explain the High Efficacy of Green Tea in Rodent Tumor Inhibition and Its Absence in Humans

Consumption of green tea (GT) and GT polyphenols has prevented a range of cancers in rodents but has had mixed results in humans. Human subjects who drank GT for weeks showed changes in oral microbiome. However, GT-induced changes in RNA in oral epithelium were subject-specific, suggesting GT-induced changes of the oral epithelium occurred but differed across individuals. In contrast, studies in rodents consuming GT polyphenols revealed obvious changes in epithelial gene expression. GT polyphenols are poorly absorbed by digestive tract epithelium. Their metabolism by gut/oral microbial enzymes occurs and can alter absorption and function of these molecules and thus their bioactivity. This might explain the overall lack of consistency in oral epithelium RNA expression changes seen in human subjects who consumed GT. Each human has different gut/oral microbiomes, so they may have different levels of polyphenol-metabolizing bacteria. We speculate the similar gut/oral microbiomes in, for example, mice housed together are responsible for the minimal variance observed in tissue GT responses within a study. The consistency of the tissue response to GT within a rodent study eases the selection of a dose level that affects tumor rates. This leads to the theory that determination of optimal GT doses in a human requires knowledge about the gut/oral microbiome in that human.

Functional Landscape of Dysregulated MicroRNAs in Oral Squamous Cell Carcinoma: Clinical Implications

MicroRNA (miRNA) dysregulation is associated with the pathogenesis of oral squamous cell carcinoma (OSCC), and its elucidation could potentially provide information on patient outcome. A growing body of translational research on miRNA biology is focusing on precision oncology, aiming to decode the miRNA regulatory network in the development and progression of cancer. Tissue-specific expression and stable presence in all body fluids are unique features of miRNAs, which could be potentially exploited in the clinical setting. Recent understanding of miRNA properties has led them to be useful, attractive, and potential tools either as biomarkers (distinct miRNA expression signature) for diagnosis and prognostic outcomes or as targets for novel therapeutic entities, enabling personalized treatment for OSCC. In this review, we discuss recent research on different aspects of alterations in miRNA profiles along with their clinical significance and strive to identify probable potential miRNA biomarkers for diagnosis and prognosis of OSCC. We also discuss the current understanding and scope of development of miRNA-based therapeutics against OSCC.

CD44 and associated markers in oral rinses and tissues from oral and oropharyngeal cancer patients

OBJECTIVES

Oral and oropharyngeal squamous cell carcinoma (OOPSCC) is a debilitating disease. Salivary rinses contain soluble tumor markers including CD44 (solCD44) and total protein (TP) that may aid detection and prognosis of these aggressive tumors. Here we aim to examine the relationship between these salivary biomarkers and tissue markers p16 and CD44 and determine whether these markers can predict progression-free survival (PFS) and overall survival (OS).

MATERIALS AND METHODS

Prospective study to update biomarkers using oral rinses and tissues from OOPSC patients enrolled between 2007 and 2012 at an academic tertiary referral center. 64 cases from a 300-subject case-control study with archived tissue for immunohistochemistry were included.

RESULTS

82.8% were male, 84.4% were ever smokers, 70.3% had disease stage T3-T4, and 57.8% presented with nodal disease. Nineteen patients (25%) were p16 positive. The group with strong tissue CD44 expression in membrane and cytoplasm had higher levels of solCD44 (mean 10.73 ng/ml) than other groups (5.47 ng/ml) (p = 0.033). TP levels were significantly reduced in oral rinses from subjects with p16 universal gross tumor tissue staining (mean 0.80 vs. 1.08 mg/ml; p = 0.039). On multivariate analysis, universal CD44 gross tissue staining and TP levels ≥ 1 mg/ml demonstrated poorer PFS, with the latter also affecting OS. Poorer survival was associated with soluble CD44 ≥ 5.33 ng/ml and TP ≥ 1 mg/ml.

CONCLUSIONS

Direct associations were found between high solCD44 levels and strong membrane and cytoplasmic CD44 expression, and between high TP levels and peripheral/mixed p16 gross staining. Poorer PFS and OS are significantly associated with higher levels of solCD44 and protein in oral rinses.

Changes of serum miR-223-3p in patients with oral cancer treated with TPF regimen and the prognosis

Changes of serum miR-223-3p in patients with oral cancer treated with TPF regimen and the prognosis were investigated. Fifty patients with oral cancer treated in the Affiliated Stomatological Hospital of Jiamusi University from March 2014 to January 2016 were enrolled in the study group, while 50 healthy subjects receiving physical examinations during the same period were enrolled in the control group. Serum expression of miR-223-3p was quantified by RT-qPCR. The diagnostic value of miR-223-3p in oral cancer was analyzed by the receiver operating characteristic (ROC) curve. Expression of miR-223-3p before and after treatment was compared. The study group was divided into the remission and the non-remission group based on the treatment outcome to analyze the predictive value of miR-223-3p. Patients were followed up for 3 years. Cox regression analysis was performed to analyze the independent prognostic factors. The relative serum miR-223-3p level was lower in the study than in the control group (P<0.001). Expression of miR-223-3p was significantly higher after treatment than before (P<0.05). Spearman's correlation analysis indicated that miR-223-3p expression before treatment gradually increased with the improvement of treatment outcome (r=0.617, P<0.001). The miR-223-3p level was markedly higher in the remission than in the non-remission group (P<0.05). The area under the ROC curve of miR-223-3p was 0.797. Multivariate Cox regression analysis demonstrated that the degree of differentiation [HR: 11.862 (95% CI: 2.730-51.547)] and miR-223-3p [HR: 3.489 (95% CI: 1.447-8.413)] were independent prognostic factors. The 3-year survival of patients with high differentiation and high miR-223-3p expression was significantly higher than that of patients with poor differentiation and low miR-223-3p expression (P<0.05). In conclusion, miR-223-3p expression is low in oral cancer, and it shows potential for predicting the efficacy and prognosis of patients with oral squamous cell carcinoma (OSCC) after TPF regimen.

Effective early detection of oral cancer using a simple and inexpensive point of care device in oral rinses

INTRODUCTION

Head and neck cancer remains a challenging disease that is increasing in incidence with the majority of patients diagnosed at an advanced stage where 5-year survival is approximately 50%. Current approaches including oral-brush biopsies, fluorescence-based technologies,  and salivary molecular profiling have demonstrated some success; however, cost, ease of use, and accuracy remain limiting factors. Areas covered: This is a profile of a novel, easy to use oral rinse point-of-care (POC) test to aid in the diagnosis of oral and oropharyngeal cancer. Background science related to the challenge of oral and oropharyngeal cancer and natural history of diagnostic aids for this disease are provided. Results of studies performed for validation of a POC and laboratory test are also discussed. Expert commentary: The POC test has been validated through a case : control clinical study and a prospective European trial, using version 1.0 (v1.0), which have demonstrated consistent performance including a > 90% negative predictive value, with a sensitivity of 80%. The assay was designed to identify malignant lesions in the oral cavity and oropharynx by improving upon standard clinical assessment.

Biomarkers: paving stones on the road towards the personalized precision medicine for oral squamous cell carcinoma

Traditional therapeutics have encountered a bottleneck caused by diagnosis delay and subjective and unreliable assessment. Biomarkers can overcome this bottleneck and guide us toward personalized precision medicine for oral squamous cell carcinoma. To achieve this, it is important to efficiently and accurately screen out specific biomarkers from among the huge number of molecules. Progress in omics-based high-throughput technology has laid a solid foundation for biomarker discovery. With credible and systemic biomarker models, more precise and personalized diagnosis and assessment would be achieved and patients would be more likely to be cured and have a higher quality of life. However, this is not straightforward owing to the complexity of molecules involved in tumorigenesis. In this context, there is a need to focus on tumor heterogeneity and homogeneity, which are discussed in detail. In this review, we aim to provide an understanding of biomarker discovery and application for precision medicine of oral squamous cell carcinoma, and have a strong belief that biomarker will pave the road toward future precision medicine.

MicroRNA-196a-5p is a potential prognostic marker of delayed lymph node metastasis in early-stage tongue squamous cell carcinoma

MicroRNAs (miRs) are expected to serve as prognostic tools for cancer. However, many miRs have been reported as prognostic markers of recurrence or metastasis in oral squamous cell carcinoma patients. We aimed to determine the prognostic markers in early-stage tongue squamous cell carcinoma (TSCC). Based on previous studies, we hypothesized that miR-10a, 10b, 196a-5p, 196a-3p, and 196b were prognostic markers and we retrospectively performed miR expression analyses using formalin-fixed paraffin-embedded sections of surgical specimens. Total RNA was isolated from cancer tissues and adjacent normal tissue as control, and samples were collected by laser-capture microdissection. After cDNA synthesis, reverse transcription-quantitative polymerase chain reaction was performed. Statistical analyses for patient clinicopathological characteristics, recurrence/metastasis, and survival rates were performed to discern their relationships with miR expression levels, and the 2^−ΔΔCq method was used. miR-196a-5p levels were significantly upregulated in early-stage TSCC, particularly in the lymph node metastasis (LNM) group. The LNM-free survival rate in the low miR-196a-5p ΔΔCq value regulation group was found to be lower than that in the high ΔΔCq value regulation group (P=0.0079). Receiver operating characteristic analysis of ΔΔCq values revealed that miR-196a-5p had a P-value=0.0025, area under the curve=0.740, and a cut-off value=−0.875 for distinguishing LNM. To our knowledge, this is the first study to examine LNM-related miRs in early-stage TSCC as well as miRs and ‘delayed LNM’ in head and neck cancer. miR-196a-5p upregulation may predict delayed LNM. Our data serve as a foundation for future studies to evaluate miR levels and facilitate the prediction of delayed LNM during early-stage TSCC, which prevent metastasis when combined with close follow-up and aggressive adjuvant therapy or elective neck dissection. Moreover, our data will serve as a foundation for future studies to evaluate whether miR-196a-5p can serve as a therapeutic marker for preventing metastasis.