A microRNA signature for the differential diagnosis of salivary gland tumors

Current Insights on Salivary Gland Adenoid Cystic Carcinoma: Related Genes and Molecular Pathways

Background/Objectives: Salivary adenoid cystic carcinoma (ACC) is a rare but aggressive neoplasm that predominantly arises from the salivary glands, accounting for a significant proportion of salivary gland cancers. The aim of this literature review is to illustrate the current insights on ACC with regards to related genes and molecular pathways by analyzing original research articles from the period 2015-2025. Methods: An electronic search of literature was performed between January and February 2025 to identify all articles investigating the current insights on salivary gland adenoid cystic carcinoma and its related genes and molecular pathways. The search was conducted using MEDLINE (National Library of Medicine)-PubMed with restrictions concerning the date of publication. In particular, we focused on the period 2015-2025 using the following keywords: Salivary gland adenoid cystic carcinoma AND genes AND molecular pathways. This was followed by a manual search, and references were used to identify relevant articles. Results: In total, 41 articles were identified through the keywords. After the implementation of the time frame 2015-2025, 31 articles remained. Subsequently, by reading the titles and abstracts and thereby excluding non-original research articles and articles written in a language other than English, 23 articles remained. Conclusions: These studies identified 23 relevant genes or pathways whose analysis yielded the most recent data regarding their function. The classification of ACC is multifaceted, encompassing distinct histological subtypes that are crucial for determining prognosis and treatment approaches. Current oncological practices classify ACC based on these histological features alongside emerging genetic and molecular markers that promise to enhance our understanding of the disease's biology. Diagnostic strategies have evolved, leveraging techniques such as biopsy and molecular diagnostics, which have significantly improved the detection and characterization of ACC. Regarding treatment, the management of ACC remains a challenge due to its propensity for local invasion and metastasis, with surgery, radiation, and chemotherapy being the mainstays of therapy. The development of targeted therapies based on ACC's molecular profile will allow for a better prognosis and an enhanced quality of life of patients.

Dynamic Role of miRNAs in Salivary Gland Carcinomas: From Biomarkers to Therapeutic Targets

BACKGROUND

Salivary gland carcinomas (SGCs) are a rare group of malignant neoplasms of the head and neck region. MicroRNAs (miRNAs) are a class of small non-coding RNAs that have been associated with the control biological process and oncogenic mechanism by the regulation of gene expression at the post-transcriptional level. Recent evidence has suggested that miRNA expression may play a role in the tumorigenesis and carcinogenesis process in SGCs.

METHODS

This review provides a comprehensive literature review of the role of miRNAs expression in SGCs focusing on the diagnostic, prognostic, and therapeutic applications.

RESULTS

In this review, numerous dysregulated miRNAs have demonstrated an oncogenic and suppressor role in SGCs.

CONCLUSION

In the future, these miRNAs may eventually constitute useful diagnostic and prognostic biomarkers that may lead to a better understanding of SGCs oncogenesis. Additionally, the development of therapeutic agents based on miRNAs may be a promising target in SGC treatment.

miRNAs orchestration of salivary gland cancer- Particular emphasis on diagnosis, progression, and drug resistance

Cancer of the salivary glands is one of the five major types of head and neck cancer. Due to radioresistance and a strong propensity for metastasis, the survival rate for nonresectable malignant tumors is dismal. Hence, more research is needed on salivary cancer's pathophysiology, particularly at the molecular level. The microRNAs (miRNAs) are a type of noncoding RNA that controls as many as 30% of all genes that code for proteins at the posttranscriptional level. Signature miRNA expression profiles have been established in several cancer types, suggesting a role for miRNAs in the incidence and progression of human malignancies. Salivary cancer tissues were shown to have significantly aberrant levels of miRNAs compared to normal salivary gland tissues, supporting the hypothesis that miRNAs play a crucial role in the carcinogenesis of salivary gland cancer (SGC). Besides, several SGC research articles reported potential biomarkers and therapeutic targets for the miRNA-based treatment of this malignancy. In this review, we will explore the regulatory impact of miRNAs on the processes underlying the molecular pathology of SGC and provide an up-to-date summary of the literature on miRNAs that impacted this malignancy. We will eventually share information about their possible use as diagnostic, prognostic, and therapeutic biomarkers in SGC.

Identification of MicroRNA Expression Profiles Related to the Aggressiveness of Salivary Gland Adenoid Cystic Carcinomas

Adenoid cystic carcinoma (ACC) has been reported as the second most common carcinoma of the salivary glands. Few studies have associated miRNA expression with ACC aggressiveness. In this study, we evaluated the miRNA profile of formalin-fixed, paraffin-embedded (FFPE) samples of salivary gland ACC patients using the NanoString platform. We studied the miRNA expression levels associated with the solid growth pattern, the more aggressive histologic feature of ACCs, compared with the tubular and cribriform growth patterns. Moreover, the perineural invasion status, a common clinicopathological feature of the disease that is frequently associated with the clinical progression of ACC, was investigated. The miRNAs showing significant differences between the study groups were selected for target prediction and functional enrichment, which included associations with the disease according to dedicated databases. We observed decreased expression of miR-181d, miR-23b, miR-455, miR-154-5p, and miR-409 in the solid growth pattern compared with tubular and cribriform growth patterns. In contrast, miR-29c, miR-140, miR-195, miR-24, miR-143, and miR-21 were overexpressed in patients with perineural invasion. Several target genes of the miRNAs identified have been associated with molecular processes involved in cell proliferation, apoptosis, and tumor progression. Together, these findings allowed the characterization of miRNAs potentially associated with aggressiveness in salivary gland adenoid cystic carcinoma. Our results highlight important new miRNA expression profiles involved in ACC carcinogenesis that could be associated with the aggressive behavior of this tumor type.

Unraveling the Role of Epithelial-Mesenchymal Transition in Adenoid Cystic Carcinoma of the Salivary Glands: A Comprehensive Review

Salivary adenoid cystic carcinoma (SACC) is considered a challenging malignancy; it is characterized by a slow-growing nature, yet a high risk of recurrence and distant metastasis, presenting significant hurdles in its treatment and management. At present, there are no approved targeted agents available for the management of SACC and systemic chemotherapy protocols that have demonstrated efficacy remain to be elucidated. Epithelial-mesenchymal transition (EMT) is a complex process that is closely associated with tumor progression and metastasis, enabling epithelial cells to acquire mesenchymal properties, including increased mobility and invasiveness. Several molecular signaling pathways have been implicated in the regulation of EMT in SACC, and understanding these mechanisms is crucial to identifying new therapeutic targets and developing more effective treatment approaches. This manuscript aims to provide a comprehensive overview of the latest research on the role of EMT in SACC, including the molecular pathways and biomarkers involved in EMT regulation. By highlighting the most recent findings, this review offers insights into potential new therapeutic strategies that could improve the management of SACC patients, especially those with recurrent or metastatic disease.

Prognostic impact of MUC1 and potential regulatory miR-145 and miR-21 expression in salivary mucoepidermoid carcinoma

BACKGROUND

Salivary gland mucoepidermoid carcinoma (MEC) poses a considerable risk of locoregional and distant metastasis after conventional treatments. There is an evident need for specifying prognostic biomarkers to identify patients who are in need of more intensive and prolonged follow-ups. This study aimed to assess the mucin 1 (MUC1) expression level and its potential regulatory microRNAs in salivary gland MEC and their prognostic potentials.

MATERIALS AND METHODS

The expression of MUC1 in salivary gland MEC tissues was assessed in 47 samples using immunohistochemistry. Related microRNA (miR-145 and miR-21) were evaluated using quantitative Reverse Transcription PCR. The associations between MUC1 and microRNAs expressions and clinicopathological parameters were investigated.

RESULTS

MUC1 expression levels positively correlated with histologic grade (p < 0.001), clinical stage (p = 0.04), risk of nodal metastasis (p = 0.02), as well as the likelihood of opting for radical treatment (p = 0.01). Increased expression of miR-21 (p < 0.001) and decreased expression of miR-145 (p < 0.001) were observed in MECs compared to normal salivary gland tissue. MiR-145 negatively (p = 0.01) and miR-21 positively (p = 0.01) correlated with MUC1 overexpression. Based on the univariate cox proportional hazard model, histologic grade and MUC1 expression level were significantly associated with disease-free, cancer-specific, and overall survival. However, the multivariable cox proportional hazard model indicated tumor grade as the only prognostic factor associated with disease-free survival.

CONCLUSION

Our results support the tumor suppressor role of miR-145 and the oncogenic role of miR-21 in salivary gland MEC. Also, MUC1 and miR-145 overexpression, as well as miR-21 suppression, show promising association with histologic tumor grade and clinical stage.

MicroRNAs’ Crucial Role in Salivary Gland Cancers’ Onset and Prognosis

Simple Summary

Salivary gland cancers are incredibly heterogeneous, both in the physical onset and in the aggressiveness. Setting up a novel diagnostic and prognostic detection method based on the noninvasive microRNAs’ profiling might represent a goal for the clinical management of those particular malignancies, saving precious time for the patients.

Abstract

Salivary gland cancer (SGC) is an uncommon and heterogeneous disease that accounts for around 8.5% of all head and neck cancers. MicroRNAs (miRNAs) consist of a class of highly conserved, short, single-stranded segments (18–25 nucleotides) of noncoding RNA that represent key gene-transcription regulators in physiological and pathological human conditions. However, their role in SGC development and progression is not completely clear. This review aims to compile and summarize the recent findings on the topic, focusing on the prognostic and diagnostic value of the major modulated and validated microRNAs in SGC. Their differential expression could possibly aid the clinician in delivering an early diagnosis, therapeutic strategy and precision medicine.

Serum metabolomics reveals an innovative diagnostic model for salivary gland tumors

An early diagnosis of salivary gland tumors (SGTs) and determination of their malignancy are conducive to developing individualized therapeutic strategies and thus improving prognosis. The aim of this study was to investigate the difference of serum metabolic profiles in patients with SGTs to better understand the mechanism of this disease and disease risk stratification. We used ultrahigh-performance liquid chromatography Q Exactive mass spectrometry and multivariate statistical analyses to conduct a comprehensive analysis of serum metabolites in a population with normal control and SGTs. 32 differentially expressed metabolites were identified, while the level of serine and lactic acid were investigated to gradually upregulate in benign SGTs and malignant SGTs. Then, the expression of serine and lactic acid were assessed in validation cohort using multiple reaction monitoring (MRM) based targeted metabolite analysis. A risk score formula based on the amount of serine and lactic acid was developed and explored to be significantly related to benign SGTs and malignant SGTs in discovery and validation cohort. Our work highlights the possible use of the risk score assessment based on the serum metabolites not only reveal in the early diagnosis of SGTs but also assist in enhancing current therapeutic strategies in the clinic.

Identification of differentially expressed microRNAs as potential biomarkers for carcinoma ex pleomorphic adenoma

Carcinoma ex pleomorphic adenoma (CXPA) is a rare malignancy that transforms from PA. Early detection of the carcinoma by biopsy is difficult due to similar histopathology of the malignant and benign components. To address this, we investigated and compared the characteristic miRNA expression patterns across samples of the PA, carcinomatous portions (CA) of CXPA, as well as conventional PA. We selected 13 CXPA and 16 conventional PA FFPE samples, separated the PA and CA portions of CXPA samples and conducted miRNA profiling for each group. Among 13 transcripts that were differentially expressed between PA and CA of CXPA, eight miRNAs were up-regulated and five down-regulated in CA. Bioinformatic analysis revealed that the up-regulated miRNAs were related to cancer progression and down-regulated ones to tumor suppression. Additionally, seven miRNAs were significantly up-regulated in PA of CXPA compared to conventional PA, although they are histopathologically similar. Almost all of these transcripts interacted with TP53, a well-known tumor suppressor. In conclusion, we identified differentially expressed miRNAs in PA and CA of CXPA, which were closely associated with TP53 and various cancer-related pathways. We also identified differentially expressed miRNAs in the PA of CXPA and conventional PA which may serve as potential biomarkers.

AN INTEGRATED APPROACH TO THE MORPHOLOGICAL DIAGNOSIS OF DIFFERENT TYPES OF PLEOMORPHIC ADENOMAS OF THE SALIVARY GLAND: LONG-TERM RESEARCH RESULTS

OBJECTIVE

The aim: To describe an integrated approach to the morphological diagnosis of different types of pleomorphic adenomas of the salivary gland.

PATIENTS AND METHODS

Materials and methods: Surgical and biopsy material from 30 patients with pleomorphic adenomas of epithelial, mixed and mesenchymal variants was studied using histological, immunohistochemical, genetic, morphometric and statistical methods.

RESULTS

Results: The results of research allowed us to identify methods for determination the pleomorphic adenomas types. The first method requires an immunohistochemical reaction with a monoclonal antibody to human papillomavirus type 16, followed by counting the percentage of positively stained cells in the tumor. Thus, the mesenchymal variant of the tumor is diagnosed when the percentage of positively stained cells is < 40%. In the mixed variant, this indicator is ≥ 40%, but ≤ 70%, and in epithelial variant - > 70%. The second method was based on the multivariate discriminant analysis. Three formulae were derived to determine the tumor types (Fmesenchymal = - 41.03 + 4.96Х1 + 1.11Х2, Fepithelial = - 22.27 + 3.46Х1 + 0.85Х2, Fmixed = - 122.25 + 5.63Х1 + 3.2Х2, here Х1 - number of vessels, Х2 - specific volume of parenchyma).

CONCLUSION

Conclusions: The authors identified several methods for determining the histological variants of pleomorphic adenomas. These methods will improve the morphological diagnosis of pleomorphic adenomas variants in the preoperative and postoperative periods.

Implication of microRNAs in Carcinogenesis with Emphasis on Hematological Malignancies and Clinical Translation

MicroRNAs (miRNAs) are evolutionarily conserved small non-coding RNAs, that are involved in the multistep process of carcinogenesis, contributing to all established hallmarks of cancer. In this review, implications of miRNAs in hematological malignancies and their clinical utilization fields are discussed. As components of the complex regulatory network of gene expression, influenced by the tissue microenvironment and epigenetic modifiers, miRNAs are “micromanagers” of all physiological processes including the regulation of hematopoiesis and metabolic pathways. Dysregulated miRNA expression levels contribute to both the initiation and progression of acute leukemias, the metabolic reprogramming of malignantly transformed hematopoietic precursors, and to the development of chemoresistance. Since they are highly stable and can be easily quantified in body fluids and tissue specimens, miRNAs are promising biomarkers for the early detection of hematological malignancies. Besides novel opportunities for differential diagnosis, miRNAs can contribute to advanced chemoresistance prediction and prognostic stratification of acute leukemias. Synthetic oligonucleotides and delivery vehicles aim the therapeutic modulation of miRNA expression levels. However, major challenges such as efficient delivery to specific locations, differences of miRNA expression patterns between pediatric and adult hematological malignancies, and potential side effects of miRNA-based therapies should be considered.

miR-22 and miR-205 Drive Tumor Aggressiveness of Mucoepidermoid Carcinomas of Salivary Glands

Objectives

To integrate mRNA and miRNA expression profiles of mucoepidermoid carcinomas (MECs) and normal salivary gland (NSGs) tissue samples and identify potential drivers.

Material and Methods

Gene and miRNA expression arrays were performed in 35 MECs and six NSGs.

Results

We found 46 differentially expressed (DE) miRNAs and 3,162 DE mRNAs. Supervised hierarchical clustering analysis of the DE transcripts revealed two clusters in both miRNA and mRNA profiles, which distinguished MEC from NSG samples. The integrative miRNA-mRNA analysis revealed a network comprising 696 negatively correlated interactions (44 miRNAs and 444 mRNAs) involving cell signaling, cell cycle, and cancer-related pathways. Increased expression levels of miR-205-5p and miR-224-5p and decreased expression levels of miR-139-3p, miR-145-3p, miR-148a-3p, miR-186-5p, miR-338-3p, miR-363-3p, and miR-4324 were significantly related to worse overall survival in MEC patients. Two overexpressed miRNAs in MEC (miR-22 and miR-205) were selected for inhibition by the CRISPR-Cas9 method. Cell viability, migration, and invasion assays were performed using an intermediate grade MEC cell line. Knockout of miR-205 reduced cell viability and enhanced ZEB2 expression, while miR-22 knockout reduced cell migration and invasion and enhanced ESR1 expression. Our results indicate a distinct transcriptomic profile of MEC compared to NSG, and the integrative analysis highlighted miRNA-mRNA interactions involving cancer-related pathways, including PTEN and PI3K/AKT.

Conclusion

The in vitro functional studies revealed that miR-22 and miR-205 deficiencies reduced the viability, migration, and invasion of the MEC cells suggesting they are potential oncogenic drivers in MEC.

High Diagnostic and Prognostic Value of miRNAs Compared with the Carcinoembryonic Antigen as a Traditional Tumor Marker

A significant challenge in cancer detection and treatment is early diagnosis and accurate prognosis of the disease that enables effective therapies and interventions to improve the patient's condition. Up to now, many parts of research have tended to focus on the carcinoembryonic antigen (CEA) to detect cancers and estimate the survival rates of patients with multiple cancer types, including colorectal, breast, non-small cell lung, and pancreas cancer. Limited sensitivity and specificity of this traditional tumor marker make it an inappropriate biomarker to diagnose cancer, especially in the early stages, while several lines of research have introduced miRNAs as reliable indicators of tumor initiation, development, and therapy response. Indeed, miRNAs have unique properties that provide considerable benefits, such as discriminating benign diseases from malignancies, prediction of cancer possibility and progress, checking sensitivity to treatment, and initial detection of tumors. This review summarizes the relationships between miRNAs and CEA, the diagnostic significance of CEA in combination with miRNAs, and the distinct advantages of miRNAs over CEA as tumor biomarkers. Advancement in our current understanding of miRNAs is essential to discover new and effective biomarkers for diagnostic, prognostic, and therapeutic goals of cancer patients.

Expressions of microRNA-29a and microRNA-34a in pleomorphic adenomas of salivary glands

Background

The most common type of salivary gland tumor is pleomorphic adenoma. The genetic area of focus in the diagnosis of salivary gland tumors is a study of the role of miRNA.

Methods

Twenty-two patients with pleomorphic adenomas of the salivary glands were used for the examinations. The histological typing of the salivary gland tumors was performed when using routine staining with hematoxylin and eosin, as well as with immunohistochemistry. The expressions of miR-34a and miR-29a were evaluated by using reverse transcription and the quantitative polymerase chain reaction in a real-time setting. In addition, the study also calculated the levels of expression of miR-29a and miR-34a in the venous blood.

Results

The majority of patients-15 (68.18%) and 22 (100.00%) had a positive response to human papillomavirus (HPV) and pleomorphic adenoma gene 1 (PLAG1), respectively. The conducted analyses of the expressions of miR-34a and miR-29a showed that the highest expression was observed in the salivary gland tissue adjacent to the tumor (1,052.02±367.20 and 111.93±56.97, versus 47.72±28.93 and 8.12±4.40 in the intact salivary gland tissue, respectively).

Conclusions

There was a sufficiently high level of miR-34a and miR-29a expressions in the tissues of the tumor of pleomorphic adenomas of the salivary glands when compared with the intact salivary gland tissue.

MicroRNA-140-5p inhibits salivary adenoid cystic carcinoma progression and metastasis via targeting survivin

Background

Salivary adenoid cystic carcinoma (SACC) is one of the most frequent carcinomas derived from the salivary gland. Growing evidence implied the involvement of microRNAs (miRNAs) in SACC progression and metastasis. This study aimed to determine the regulatory role of miR-140-5p in SACC progression and metastasis and to explore the underlying mechanisms.

Materials and methods

MiR-140-5p and survivin mRNA expression levels were determined by quantitative real-time PCR; protein levels were evaluated by western blot assay; cell proliferation, growth, invasion, apoptosis and caspase-3 activity were evaluated by respective in vitro functional assays; xenograft nude mice model was used to assess the in vivo tumor growth; a luciferase reporter assay determined the interaction between miR-140-5p and survivin.

Results

MiR-140-5p overexpression suppressed SACC cell proliferation and invasion, induced cell apoptosis and inhibited in vivo tumor growth of SACC cells. The loss-of-function studies showed that miR-140-5p knockdown enhanced SACC cell proliferation and invasion, inhibited cell apoptosis and led to an accelerated in vivo tumor growth. The bioinformatics prediction and luciferase reporter assay revealed that miR-140-5p directly targeted survivin 3′ untranslated region, and survivin was inversely regulated by miR-140-5p. Knockdown of survivin exerted tumor-suppressive effects on SACC cells, while enforced expression of survivin counteracted the tumor-suppressive actions of miR-140-5p overexpression in SACC cells. Mechanistically, miR-140-5p modulated the protein expression levels of apoptosis- and epithelial-mesenchymal transition-related mediators as well as matrix metallopeptidase-2/-9 via targeting survivin. More importantly, the down-regulation of miR-140-5p and the up-regulation of survivin were detected in the SACC clinical tissues, and miR-140-5 expression was inversely correlated with survivin mRNA expression level in SACC tissues.

Conclusion

Our data indicated that miR-140-5p suppressed SACC cell proliferation and invasion, induced cell apoptosis via regulating survivin expression. The present study provide evidence that that miR-140-5p could be a promising target for treating SACC, which requires further investigations.