Circulating miR-21 as a prognostic and predictive biomarker in oral squamous cell carcinoma

Impact of Human Papillomavirus on microRNA-21 Expression in Oral and Oropharyngeal Cancer-A Systematic Review

Recently, microRNAs (miR) were identified to have potential links with oral squamous cell carcinoma (OSCC) and oropharyngeal squamous cell carcinoma (OPSCC) oncogenesis, specifically miR-21. Since HPV is a major risk factor for the development of these diseases, we aimed to search the literature regarding miR-21 expression in both HPV-positive and HPV-negative OSCC/OPSCC. The search was performed in the PubMed (MEDLINE), Scopus, Web of Science, and Cochrane electronic databases. The research question was as follows: Is there a difference in the tissue expression of miR-21 between patients with HPV-positive and those with HPV-negative OSCC/OPSCC? After conducting a meticulous search strategy, four studies were included, and they had a pooled sample size of 621 subjects with OSCC and/or OPSCC. Three studies did not find any significant difference in miR-21 expression between HPV-positive and HPV-negative OSCC/OPSCC. The findings of this systematic review showed that there are no differences in miR-21 expression between HPV-positive and HPV-negative OSCC/OPSCC. Nevertheless, it is worth noting that there are still insufficient studies regarding this important subject, because understanding how HPV influences miR-21 expression and its downstream effects can provide insights into the molecular mechanisms underlying OSCC/OPSCC development and progression.

A PRISMA meta-analysis for diagnostic value of microRNA-21 in head and neck squamous cell carcinoma along with bioinformatics research

OBJECTIVES

The use of miR-21 expression remains vague in diagnosis of head and neck squamous cell carcinoma (HNSCC). This study aimed to systematically evaluate the diagnostic potential of the miR-21 expression in patients with HNSCCs through investigating and summarizing the results reported in the literature.

METHODS

Extant medical databases were examined for articles of clinical study assessing the miR-21 expression in HNSCC cases, published in the past 20 years. Bioinformatics research was also performed for finding miR-21 targets differentially expressed in HNSCC so as to present their biological behaviors.

RESULTS

Our meta-analysis comprised 11 studies including 622/450 cases in HNSCC/control group. Forest plots displayed miR-21 which possessed significantly good specificity (0.76, p < 0.001) and sensitivity (0.80, p < 0.001). Diagnostic odds ratio was 2.46 (95% CI 1.87-3.24). Positive and negative likelihood ratio was 3.40 (95% CI 1.94-5.97) and 0.26 (95% CI 0.18-0.38), respectively. Area under the receiver operating characteristic curve was 0.85.

CONCLUSION

This study is the highest level of evidence presently available in diagnosing HNSCC. This PRISMA meta-analysis indicated that the pooled results were robust, confirming the oncogenic potential of miR-21 that could be used successfully as a screening biomarker in HNSCC patients. Specifically, the overexpression of miR-21 in these patients presents a worse survival outcome.

Unraveling the role of miRNAs in the diagnosis, progression, and drug resistance of oral cancer

Oral cancer (OC) is a widely observed neoplasm on a global scale. Over time, there has been an increase in both its fatality and incidence rates. Oral cancer metastasis is a complex process that involves a number of cellular mechanisms, including invasion, migration, proliferation, and escaping from malignant tissue through either lymphatic or vascular channels. MicroRNAs (miRNAs) are a crucial class of short non-coding RNAs recognized as significant modulators of diverse cellular processes and exert a pivotal influence on the carcinogenesis pathway, functioning either as tumor suppressors or as oncogenes. It has been shown that microRNAs (miRNAs) have a role in metastasis at several stages, including epithelial-mesenchymal transition, migration, invasion, and colonization. This regulation is achieved by targeting key genes involved in these pathways by miRNAs. This paper aims to give a contemporary analysis of OC, focusing on its molecular genetics. The current literature and emerging advancements in miRNA dysregulation in OC are thoroughly examined. This project would advance OC diagnosis, prognosis, therapy, and therapeutic implications.

Differential Expression Profile of Salivary oncomiRNAs among Smokeless Tobacco Users

OBJECTIVE

 The aim of this study was to evaluate the expression of selected salivary oncomiRNAs among smokeless tobacco users and nonsmokers.

MATERIALS AND METHODS

 Twenty-five subjects with chronic smokeless tobacco habit (> 1 year) and 25 nonsmokers were selected for this study. MicroRNA was extracted from saliva samples using the miRNeasy Kit (Qiagen, Hilden, Germany). The forward primers used in the reactions include hsa-miR-21-5p, hsa-miR-146a-3p, hsa-miR-155-3p, and hsa-miR-199a-3p. Relative expression of miRNAs was calculated using the 2-ΔΔCt method. Fold change is calculated by raising 2 to the power of the negative ΔΔCT value.

STATISTICAL ANALYSIS

 Statistical analysis was carried out using GraphPad Prism 5 software. A p-value less than 0.05 was considered statistically significant.

RESULTS

 The four tested miRNAs were found overexpressed in saliva of subjects with smokeless tobacco habit when compared with saliva from nontobacco users. miR-21 expression was 3.74 ± 2.26 folds higher among subjects with smokeless tobacco habit compared to nontobacco users (p < 0.01). The expression for miR-146a (5.56 ± 8.3 folds; p < 0.05), miR-155 (8.06 ± 23.4 folds; p < 0.0001) and miR-199a (14.39 ± 30.3 folds; p < 0.05) was significantly higher among subjects with smokeless tobacco habit.

CONCLUSION

 Smokeless tobacco leads to salivary overexpression of the miRs 21, 146a, 155, and 199a. Monitoring the levels of these four oncomiRs may provide insight about the future development of oral squamous cell carcinoma, especially in patients with smokeless tobacco habits.

Exploring Possible Diagnostic Precancerous Biomarkers for Oral Submucous Fibrosis: A Narrative Review

Oral submucous fibrosis (OSF) stands as a progressive oral ailment, designated as a potentially malignant disorder. OSF has gained widespread recognition as a significant precursor to malignant transformation. In the pursuit of dependable, straightforward, and non-invasive diagnostic measures for the early detection of oral malignant progression, research has delved into potential diagnostic biomarkers of OSF. This comprehensive review delves into current investigations that explore the correlation between various biomarkers and OSF. The molecular biomarkers of OSF are categorized based on cytology and sampling methods. Moreover, this review encompasses pertinent studies detailing how these biomarkers are acquired and processed. Within this scope, we scrutinize four potential biomarkers that hold the promise of facilitating the development of diagnostic tools for detecting early-stage OSF.

Mir-21 and Mir-125b as theranostic biomarkers for epithelial ovarian cancer in Tunisian women

Background

Ovarian cancer (OC) is the third most common cancer in women and the leading cause of death associated with gynecologic tumors. Because this disease is asymptomatic in the early stages, most patients are not diagnosed until the late stages. This highlights the need for the development of diagnostic biomarkers. MicroRNAs (miRNAs), small non-coding RNAs, are currently being explored as potential biomarkers for the early detection of various malignancies in humans. However, their expression and diagnostic value in OC have not been well studied.

Materials and Methods

the plasma levels of miR-21, miR-200a, miR-200b, miR-200c, miR-205 and miR-125b were determined in epithelial ovarian cancer (EOC) patients and healthy controls by Reverse Transcription Quantitative Realtime Polymerase Chain Reaction (RT-qPCR). The expression levels of the deregulated microRNAs were analysed according to clinical characteristics.

Results

It was found that miR-21 and miR-125b were upregulated in EOC compared with healthy controls. Moreover, decreased miR-125b was associated with resistance to platinum-based chemotherapy.

Conclusions

Our data suggest that miR-21 and miR-125b in plasma may serve as potential circulating biomarkers for the early detection of EOC. MiR-125b may also be useful for predicting chemosensitivity in EOC patients.

Relevance of micro-RNAs and their targets as a diagnostic and prognostic marker in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) ranks sixth among all cancers in the world, affecting various sites of the oral cavity with associated several risk factors. High mortality has been associated with the presence of metastasis during the time of diagnosis and an increase in therapeutic relapses. Micro-RNAs (miRNAs) are a group of small non-coding RNAs with salient roles in the initiation and progression of cancer. The tumorigenesis of OSCC is associated with the dysregulation of several miRNAs. MicroRNAs are an area of recent interest, and numerous studies have been reported and are being undertaken to identify their role in diagnostic and prognostic value for oral cancers. Most of the miRNA processing machinery is considered to be either up-/down-regulated in OSCC, but the underlying mechanism of miRNA dysregulation and their activity as either a tumour suppressor or an oncogene in oral carcinogenesis is not yet clear. The article presents a concise review of the available current literature regarding the various miRNAs' signatures in OSCC and their role as diagnostic/prognostic biomarkers.

Circulating miRNA as a Biomarker in Oral Cancer Liquid Biopsy

Oral cancer is currently challenging the healthcare system, with a high incidence among the population and a poor survival rate. One of the main focuses related to this malignancy is the urge to implement a viable approach for improving its early diagnosis. By introducing the use of liquid biopsy and the identification of potential biomarkers, aiming for a noninvasive approach, new advancements offer promising perspectives in the diagnosis of oral cancer. The present review discusses the potential of circulating miRNAs as oral cancer biomarkers identified in body fluids such as serum, plasma, and saliva samples of oral cancer patients. Existing results reveal an important implication of different miRNA expressions involved in the initiation, development, progression, and metastasis rate of oral malignancy. Liquid biomarkers can play a crucial role in the development of the concept of personalized medicine, providing a wide range of clinical applications and future targeted therapies.

Zinc-alpha 2 glycoprotein a diagnostic Biomarker for early stage oral Squamous Cell Carcinoma

Objectives

In this study, we investigated the expression of zinc alpha-2 glycoprotein in oral squamous cell carcinoma tissue samples. Additionally, ascertained its association to the oral cancer stage and subscale parameters (TNM).

Methods

This observational study was conducted at Ziauddin University from January to December 2020. Using the Open-Epi software, the sample size of 120 oral squamous cell carcinomas was calculated at 95% confidence interval and a 5% margin of error. Ethical approval was taken from the Institutional Ethical Review Committee. Histologically diagnosed cases of oral squamous cell carcinoma were obtained from the Histopathology Department of Ziauddin University, Karachi. Study data was analyzed through SPSS version-20 and p-value ≤0.05 considered as significant. One-way ANOVA and Multiple linear regression were applied for analysis of data.

Result

In the study, none of the oral squamous cell carcinoma tissue samples from the later stages were stained for ZAG. However 71% (35/49) of the early stage OSCC samples showed positive IHC results for ZAG expression in the cytoplasm. One-way ANOVA indicates that high ZAG expression was significantly associated with smaller tumor size (p<0.001), lymph node involvement (p=0.002), early stages of OSCC (p<0.001) and less differentiated tumor (p=0.001). The site of the tumor was also significantly associated with ZAG staining (p<0.001).

Conclusion

Zinc alpha-2 glycoprotein expressed in the early stages of oral cancer development so that effective treatment modalities can be planned as per the patient's status. This may also assist a clinician to achieve tumor-free surgical margins and monitor the post treatment outcomes.

The clinical implications of circulating microRNAs as potential biomarkers in screening oral squamous cell carcinoma

Background

Recent studies have highlighted the biomarker role of circulating miRNAs in oral squamous cell carcinoma (OSCC), indicating their potential application as early diagnostic markers for OSCC. However, the diagnostic results have proven inconclusive. This study was conducted to evaluate the diagnostic value of circulating miRNAs for OSCC diagnosis.

Methods

Eligible published studies were identified by a literature search carried out in several databases by using combinations of keywords associated with OSCC, circulating miRNAs, and diagnosis. The bivariate meta-analysis model was adopted to summarize the pooled parameters. Afterwards, we thoroughly explored the sources of heterogeneity after evaluating the risk of bias.

Results

A total of 60 studies focusing on 41 circulating miRNAs were included. The pooled sensitivity, specificity, and AUC were 0.75 (95%CI: 0.69-0.80), 0.76 (0.70-0.81), 0.82 (0.79-0.85), respectively. Subgroup analyses showed that miRNA combinations were more accurate than single miRNAs. Additionally, plasma may be a better matrix for miRNAs assays in OSCC diagnosis as the plasma-based miRNA assay had a higher level of diagnostic accuracy than serum-based miRNA assay. Subgroup analyses also suggested that using circulating miRNAs for OSCC diagnosis is more effective in Caucasians than in Asian ethnic groups. Finally, circulating miRNA assays based on large sample sizes have superior diagnostic accuracy than small sample sizes.

Conclusion

Circulating miRNAs might be applied as effective surrogate biomarkers for early diagnosis of OSCC. Nevertheless, future larger-scale prospective studies should be performed to enhance the diagnostic efficiency and investigate the miRNA combinations with more pronounced accuracy.

Liquid biopsy in the assessment of microRNAs in oral squamous cell carcinoma: A systematic review

Background

The identification of non-invasive biomarkers from biological fluids collected by liquid biopsy provides new horizons for individualized therapeutic strategies and improves clinical decision-making in OSCC patients. Circulating microRNAs have emerged as biomarkers that may reflect not only the existence of cancer, but also the dynamic, malignant potential, and drug resistance of tumors. The aim of the systematic review is to evaluate and summarize the results of the published studies regarding the use of microRNAs as biomarkers for OSCC.

Material and Methods

A literature search was conducted on PubMed, Scopus, Web of Science, and Cochrane databases till November 2020. A total of 34 studies met the inclusion criteria and were therefore subjected to quality assessment. Each study was subjected to data extraction including; patient characteristics, type of fluid sample (whole blood, plasma, serum, or saliva), molecular analysis method, specific dysregulated microRNA, and microRNA expression pattern.

Results

The analysis showed that 57 microRNAs of liquid biopsy samples of four different fluids (whole blood, serum, plasma, and saliva) were analyzed. The prognostic and therapeutic significance of these microRNAs were suggested by several studies; where 41 microRNAs were upregulated while 16 were downregulated.

Conclusions

Scientific evidence supports the interest in the use of microRNAs in the diagnosis and prognosis in OSCC patients; however, further studies in a larger cohort of patients are mandatory to introduce liquid biopsy in the routine clinical practice for the OSCC management. Key words:Biomarkers, liquid biopsy, microRNA, oral squamous cell carcinoma, systematic review.

Epigenetic Regulations of Perineural Invasion in Head and Neck Squamous Cell Carcinoma

Carcinomas of the oral cavity and oropharynx belong among the ten most common malignancies in the human population. The prognosis of head and neck squamous cell carcinoma (HNSCC) is determined by the degree of invasiveness of the primary tumor and by the extent of metastatic spread into regional and distant lymph nodes. Moreover, the level of the perineural invasion itself associates with tumor localization, invasion's extent, and the presence of nodal metastases. Here, we summarize the current knowledge about different aspects of epigenetic changes, which can be associated with HNSCC while focusing on perineural invasion (PNI). We review epigenetic modifications of the genes involved in the PNI process in HNSCC from the omics perspective and specific epigenetic modifications in OSCC or other neurotropic cancers associated with perineural invasion. Moreover, we summarize DNA methylation status of tumor-suppressor genes, methylation and demethylation enzymes and histone post-translational modifications associated with PNI. The influence of other epigenetic factors on the HNSCC incidence and perineural invasion such as tobacco, alcohol and oral microbiome is overviewed and HPV infection is discussed as an epigenetic factor associated with OSCC and related perineural invasion. Understanding epigenetic regulations of axon growth that lead to tumorous spread or uncovering the molecular control of axon interaction with cancer tissue can help to discover new therapeutic targets for these tumors.

The Connection between MicroRNAs and Oral Cancer Pathogenesis: Emerging Biomarkers in Oral Cancer Management

Oral cancer is a common human malignancy that still maintains an elevated mortality rate despite scientific progress. Tumorigenesis is driven by altered gene expression patterns of proto-oncogenes and tumor-suppressor genes. MicroRNAs, a class of short non-coding RNAs involved in gene regulation, seem to play important roles in oral cancer development, progression, and tumor microenvironment modulation. As properties of microRNAs render them stable in diverse liquid biopsies, together with their differential expression signature in cancer cells, these features place microRNAs at the top of promising biomarkers for diagnostic and prognostic values. In this review, we highlight eight expression levels and functions of the most relevant microRNAs involved in oral cancer development, progression, and microenvironment sustainability. Furthermore, we emphasize the potential of using these small RNA species as non-invasive biomarkers for the early detection of oral cancerous lesions. Conclusively, we highlight the perspectives and limitations of microRNAs as novel diagnostic tools, as well as therapeutic models.

MicroRNA31 and MMP-1 contribute to the differentiated pathway of invasion -with enhanced epithelial-to-mesenchymal transition- in squamous cell carcinoma of the skin

Epithelial to mesenchymal transition (EMT) is an important mechanism of invasion in cutaneous squamous cell carcinomas (cSCCs) and has been found to be enhanced in tumors originated from actinic keratosis with transformation limited to the basal epithelial layer -differentiated pathway-, compared to cases with invasion subsequent to complete epidermal transformation -classical pathway-. Several microRNAs and proteins can contribute to EMT modulation in cSCCs. MicroRNA21 and microRNA31 are involved in posttranscriptional regulation of protein expression and could play a relevant role in EMT and cSCC progression. Throughout the EMT process upregulation of matrix metalloproteinases (MMPs) enhances invasiveness and MMP-1 and MMP-3 contribute to local invasion, angiogenesis and metastasis in cSCCs. Additionally, cSCC development is associated with PTEN loss and NF-κB, NOTCH-1 and p63 activation. The aim of this work is to identify differences in the expression of those molecules between both pathways of cSCCs development. Eight tissue microarrays from 80 consecutive cSCCs were analyzed using LNA-based miRNA in situ hybridization for miRNA21 and miRNA31 evaluation, and immunohistochemistry for MMP-1, MMP-3, PTEN, NOTCH-1, NF-κB, p63 and CD31. Significantly higher expression of miRNA31 (p < 0.0001) and MMP-1 (p = 0.0072) and angiogenesis (p = 0.0199) were found in the differentiated pathway, whereas PTEN loss (p = 0.0430) was more marked in the classical pathway. No significant differences were found for the other markers. Our findings support a contribution of miRNA31 and MMP-1 in the differentiated pathway, associated to EMT and increased microvascularization. The greater PTEN loss in the classical pathway indicate that its relevance in cSCC is not EMT-related.

Expression of microRNA-21 in saliva and tumor tissue of patients with oral squamous cell carcinoma: a predictor of cervical lymph node metastasis

OBJECTIVE

Evaluation of diagnostic accuracy of microRNA-21 (miR-21) in saliva and tumor tissue for presurgical assessment of lymph node metastasis in patients with oral squamous cell carcinoma (OSCC).

STUDY DESIGN

Unstimulated whole saliva and tumor tissue was obtained from clinically suspected patients with OSCC. A total of 130 patients diagnosed with OSCC were included as study participants. The assessment of cervical lymph node metastasis was done before surgery using imaging scans and post surgically confirmed by histopathologic examination of excised lymph nodes. miR-21 expression was evaluated using real-time polymerase chain reaction. The data was statistically analyzed for correlation analysis, cutoff values, sensitivity, and specificity. The κ statistic was applied to assess the degree of agreement between the lymph node metastasis and miR-21 expression.

RESULTS

miR-21 expression showed a statistically significant correlation with cervical lymph node metastasis with a diagnostic accuracy of 65% to 71.54% in saliva and 69% to 81.54% in tumor tissue. Very good agreement was observed between tumor tissue miR-21-3p and cervical lymph node metastasis with a specificity of 80.60% and a sensitivity of 82.40%.

CONCLUSIONS

miR-21 expression in saliva and tumor tissue of patients with OSCC showed high diagnostic accuracy for assessment of cervical lymph node metastasis. It can be used as an alternative for assessment of cervical lymph node metastasis before surgery.

Systematic review and meta-analysis of prognostic microRNA biomarkers for survival outcome in laryngeal squamous cell cancer

Background

Laryngeal carcinoma is a primary malignant tumor originating from the laryngeal mucosa, and its pathogenesis is not fully understood. It is a rare type of cancer that shows a downward trend in the 5-year survival rate. In clinical practice, dysregulated microRNAs are often observed in patients with laryngeal cancer. In recent years, an increasing number of studies have confirmed that the strong biomarker potential of microRNAs. We conducted a systematic review and meta-analysis to identify and highlight multiple microRNAs as biomarkers for disease prognosis in patients with laryngeal cancer.

Methods

We actively searched the systematic reviews in PubMed, Embase, Web of Science and The Cochrane Library to select the studies that met the proposed guidelines. A total of 5307 patients with laryngeal cancer were included in this study to evaluate the association between microRNAs expression levels and patient outcomes. For overall survival in the clinical stage, a hazard ratio (HR) and corresponding 95% confidence interval (CI) are calculated to assess the effect of survival.

Results

A total of 36 studies on microRNAs and laryngeal cancer recovery were included in this meta-analysis. The selected endpoints for these studies included overall survival (OS) and disease-free survival (DFS).The comorbidities of overexpression and underexpression of microRNAs were 1.13 (95% CI 1.06–1.20, P < 0.05) and 1.10 (95% CI 1.00–1.20, P < 0.05), respectively.

Conclusion

MiRNA-100, miRNA-155, miRNA-21, miRNA-34a, miRNA-195 and miR-let-7 are expected to be potential noninvasive and simple markers for laryngeal cancer.

MicroRNAs as Modulators of Oral Tumorigenesis-A Focused Review

Oral cancers constitute the majority of head and neck tumors, with a relatively high incidence and poor survival rate in developing countries. While the five-year survival rates of the oral cancer patients have increased to 65%, the overall survival for advanced stages has been at 27% for the past ten years, emphasizing the necessity for further understanding the etiology of the disease, diagnosis, and formulating possible novel treatment regimens. MicroRNAs (miRNAs), a family of small non-coding RNA, have emerged as master modulators of gene expression in various cellular and biological process. Aberrant expression of these dynamic molecules has been associated with many human diseases, including oral cancers. The deregulated miRNAs have been shown to control various oncogenic processes, including sustaining proliferative signaling, evading growth suppressors, resisting cell death activating invasion and metastasis, and inducing angiogenesis. Hence, the aberrant expression of miRNAs associated with oral cancers, makes them potential candidates for the investigation of functional markers, which will aid in the differential diagnosis, prognosis, and development of novel therapeutic regimens. This review presents a holistic insight into our understanding of the role of miRNAs in regulating various hallmarks of oral tumorigenesis.

miRNA for the assessment of lymph node metastasis in patients with oral squamous cell carcinoma: Systematic review and metanalysis

BACKGROUND

miRNA is one of the advanced epigenetic molecular markers correlating with lymph node metastasis in patients with Oral squamous cell carcinoma (OSCC). Numerous published papers are showing correlation of miRNA with metastasis. There is a need to analyze and validate such correlation.

METHOD

English language literature in major databases from the last 20 years was searched using controlled vocabulary and keywords. Strict inclusion and exclusion criteria were followed for selection of studies. The quality assessment was done as per the QUADAS tool 2 by three independent reviewers. The metanalysis was performed by using random effect model. Standardized mean difference (SMD) was considered as the effect measure. Statistical software used was STATA version 13.1.

RESULTS

With all inclusion and exclusion criteria, eight studies could qualify for metanalysis. The pooled estimate is found to be 0.13 (-0.35, 0.62), P = .585, which is statistically not significant. This indicates that there is a no significant difference in the fold change between metastasis and no metastasis groups. P-value of chi-square statistic for heterogeneity is <.001 (significant), and I-squared statistic is 87.2%, which indicates that heterogeneity is present to a considerable extent. Egger's test shows there is no publication bias involved (P = .819).

CONCLUSION

The metanalysis showed no significant difference in the fold change of miRNA expression between metastasis and non-metastasis OSCC patients. Future studies can be directed to eliminate the heterogeneity among the studies noted in this analysis to confirm the role of miRNA for assessment of regional metastasis with special focus on tongue squamous cell carcinoma.

LncRNA LINC00689 Promotes the Progression of Gastric Cancer Through Upregulation of ADAM9 by Sponging miR-526b-3p

Introduction

Increasing studies have demonstrated that noncoding RNAs, including miRNAs and lncRNAs, have vital roles in mediating cancer progression. However, the expression features and biological functions of LINC00689 in gastric cancer (GC) remain largely unknown. This study was designed to investigate the functions of LINC00689, miR-526b-3p and ADAM9 as well as their interactions in GC.

Methods

Real time PCR(RT-PCR) was used to detect the expression of LINC0068, miR-526b-3p and ADAM9 in both GC tissues or cell lines. Gain- and loss- of functions of assays were conducted to verify the role of LINC0068, miR-526b-3p and ADAM9 in GC development. Cell proliferation were determined by CCK8 assay and transwell assay and scratch wound-healing assay were used to test cell invasion and migration. Further, the relationships between LINC00689 and miR-526b-3p, miR-526b-3p and ADAM9 were predicted by bioinformatics analysis and then proved by Luciferase reporter assay and RNA Immunoprecipitation(RIP) assay.

Results

We found that LINC00689 was upregulated in GC tissues and positively correlated with advanced tumor stage and tumor size, while miR-526b-3p was downregulated. Furthermore, gain- and loss-of-function experiments revealed that LINC00689 promoted the proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) of GC cells, while miR-526b-3p had the opposite effects. The underlying mechanisms indicated that LINC00689 functioned as a competing endogenous RNA (ceRNA) by sponging miR-526b-3p in GC cells. Further investigations confirmed that ADAM9 was a direct target of miR-526b-3p and positively modulated the progression of GC.

Conclusion

Our study suggests that LINC00689 functions as a novel oncogenic lncRNA in the development of GC by promoting ADAM9 expression through suppression of miR-526b-3p.

Circulating miR-21 as a Potential Biomarker for the Diagnosis of Oral Cancer: A Systematic Review with Meta-Analysis

Head and neck squamous cell carcinoma (HNSCC) is one of the main neoformations of the head-neck region and is characterized by the presence of squamous carcinomatous cells of the multi-layered epithelium lining the oral cavity, larynx, and pharynx. The annual incidence of squamous cell carcinoma of the head and neck (HNSCC) comprises approximately 600,000 new cases globally. Currently, the 5-year survival from HNSCC is less than 50%. Surgical, radiotherapy, and chemotherapy treatments strongly compromise patient quality of life. MicroRNAs (miRNAs) are a family of small noncoding endogenous RNAs that function in regulating gene expression by regulating several biological processes, including carcinogenesis. The main upregulated microRNAs associated with oral carcinoma are miR-21, miR-455-5p, miR-155-5p, miR-372, miR-373, miR-29b, miR-1246, miR-196a, and miR-181, while the main downregulated miRNAs are miR-204, miR-101, miR-32, miR-20a, miR-16, miR-17, and miR-125b. miR-21 represents one of the first oncomirs studied. The present systematic review work was performed based on the preferred reporting items for systematic review and meta-analysis (PRISMA) protocol. A search was carried out in the PubMed and Scopus databases with the use of keywords. This search produced 628 records which, after the elimination of duplicates and the application of the inclusion and exclusion criteria, led to 7 included articles. The heterogeneity of the studies according to the odds ratio was high, with a Q value of 26.616 (p < 0.001), and the I² was 77.457% for specificity. The heterogeneity was high, with a Q value of 25.243 (p < 0.001) and the I² was 76.231% for sensitivity. The heterogeneity of data showed a Q value of 27.815 (p < 0.001) and the I² was 78.429%. Therefore, the random-effects model was selected. The diagnostic odds ratio was 7.620 (95% CI 3.613-16.070). The results showed that the sensitivity was 0.771 (95% CI 0.680-0.842) (p < 0.001) while, for specificity, we found 0.663 (95% CI 0.538-0.770) (p < 0.001). The negative likelihood ratio (NLR) was 0.321 (95% CI 0.186-0.554), and the positive likelihood ratio (PLR) was 2.144 (95% CI 1.563-2.943). The summary ROC plot demonstrates that the diagnostic test presents good specificity and sensitivity, and the area under the curve (AUC), as calculated from the graph, was 0.79.

Cell-Free microRNAs as Potential Oral Cancer Biomarkers: From Diagnosis to Therapy

Oral cavity cancer is the most frequent malignancy of the head and neck. Unfortunately, despite educational interventions for prevention and early diagnosis, oral cancer patients are often diagnosed in advanced stages associated with poor prognosis and life expectancy. Therefore, there is an urgent need to find noninvasive biomarkers to improve early detection of this tumor. Liquid biopsy has emerged as a valuable tool in medical oncology which provides new horizons for improving clinical decision making. Notably, cell-free microRNAs (miRNAs), a class of short non-coding RNAs, are emerging as novel noninvasive cancer biomarkers. Here, we provide an overview of the potential clinical application of cell-free miRNAs as diagnostic, prognostic, and therapeutic biomarkers in oral cancer.