Potential miRNA-target interactions for the screening of gastric carcinoma development in gastric adenoma/dysplasia

Androgen synthesis cell-specific CREBZF deficiency alters adrenal cortex steroid secretion and develops behavioral abnormalities in adult male mice

The global challenge of male infertility is escalating, notably due to the decreased testosterone (T) synthesis in testicular Leydig cells under stress, underscoring the critical need for a more profound understanding of its regulatory mechanisms. CREBZF, a novel basic region-leucine zipper transcription factor, regulates testosterone synthesis in mouse Leydig cells in vitro; however, further validation through in vivo experiments is essential. Our study utilized Cyp17a1-Cre to knock out CREBZF in androgen-synthesis cells and explored the physiological roles of CREBZF in fertility, steroid hormone synthesis, and behaviors in adult male mice. Conditional knockout (cKO) CREBZF did not affect fertility and serum testosterone level in male mice. Primary Leydig cells isolated from CREBZF-cKO mice showed impaired testosterone secretion and decreased mRNA levels of Star, Cyp17a1, and Hsd3b1. Loss of CREBZF resulted in thickening of the adrenal cortex, especially X-zone, with elevated serum corticosterone and dehydroepiandrosterone levels and decreased serum dehydroepiandrosterone sulfate levels. Immunohistochemical staining revealed increased expression of StAR, Cyp11a1, and 17β-Hsd3 in the adrenal cortex of CREBZF-cKO mice, while the expression of AR was significantly reduced. Along with the histological changes and abnormal steroid levels in the adrenal gland, CREBZF-cKO mice showed higher anxiety-like behavior and impaired memory in the elevated plus maze and Barnes maze, respectively. In summary, CREBZF is dispensable for fertility, and CREBZF deficiency in Leydig cells promotes adrenal function in adult male mice. These results shed light on the requirement of CREBZF for fertility, adrenal steroid synthesis, and stress response in adult male mice, and contribute to understanding the crosstalk between testes and adrenal glands.

Downregulation of cancer-associated fibroblast exosome-derived miR-29b-1-5p restrains vasculogenic mimicry and apoptosis while accelerating migration and invasion of gastric cancer cells via immunoglobulin domain-containing 1/zonula occluden-1 axis

Background: Cancer-associated fibroblast (CAF) exosomal miRNAs have gradually a hot spot in cancer therapy. This study mainly explores the effect of CAF-derived exosomal miR-29b-1-5p on gastric cancer (GC) cells.Methods: CAFs and exosomes were identified by Western blot and transmission electron microscopy. CAF-derived exosomes-GC cells co-culture systems were constructed. Effects of CAF-derived exosomal miR-29b-1-5p on GC cells were determined by cell counting kit-8, flow cytometry, wound healing, Transwell assays and Western blot. The relationship between miR-29b-1-5p and immunoglobulin domain-containing 1 (VSIG1) was assessed by TargetScan, dual-luciferase reporter and RNA immunoprecipitation (RIP) experiments. The interaction between VSIG1 and zonula occluden-1 (ZO-1) was detected by co-immunoprecipitation. Expressions of miR-29b-1-5p, VSIG1 and ZO-1 were determined by quantitative real-time PCR. Vascular mimicry (VM) was detected using immunohistochemistry and tube formation assays. Rescue experiments and xenograft tumor assays were used to further determine the effect of CAF-derived exosomal miR-29b-1-5p/VSIG1 on GC.Results: VM structure, upregulation of miR-29b-1-5p, and downregulation of VSIG1 and ZO-1 were shown in GC tissues. MiR-29b-1-5p targeted VSIG1, which interacted with ZO-1. CAF-derived exosomal miR-29b-1-5p inhibitor suppressed the viability, migration, invasion and VM formation, but promoted the apoptosis of GC cells. MiR-29b-1-5p inhibitor increased levels of VSIG1, ZO-1 and E-cadherin, whilst decreasing levels of VE-cadherin, N-cadherin and Vimentin in vitro and in vivo, which however was partially reversed by shVSIG1. Downregulation of CAF-derived exosomal miR-29b-1-5p impeded GC tumorigenesis and VM structure in vivo by upregulating VSIG1/ZO-1 expression.Conclusion: Downregulation of CAF-derived exosomal miR-29b-1-5p inhibits GC progression via VSIG1/ZO-1 axis.

Advances in our understanding of the molecular pathogenesis of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a multifactorial and complex disease. Our knowledge of the cellular and genetic basis of NEC have expanded considerably as new molecular mechanisms have been identified. This article will focus on the current understanding of the molecular pathogenesis of NEC with a focus on the inflammatory, immune, infectious, and genetic mechanisms that drive disease development.

Mangiferin Inhibits Human Lung Adenocarcinoma by Suppressing MiR-27b and MiR-92a

Lung adenocarcinoma (LUAD) is one of the most prevalent malignancies. However, its mechanism and therapeutic strategy remain to be clarified. Mangiferin is a flavonoid derived from the leaves of mango trees of the lacquer family that has many pharmacological and physiological effects. This research aimed to elucidate the biological effect of mangiferin in LUAD cell lines and clarify the in vitro mechanism of mangiferin. Mangiferin was shown to significantly restrain the proliferation of LUAD cells (A549, H1299, and H2030 cells) in a dose- and time-dependent manner. Furthermore, mangiferin was capable of stimulating apoptosis, and more cells were blocked in G1 and S phase in the mangiferin-treated cells than in those not treated with mangiferin. Microarrays and micro-RNA sequencing data suggested that there is a higher level of miR-27b and miR-92a in LUAD tissues than in non-LUAD tissues. Additional experiments indicated that mangiferin may be related to the downregulated levels of miR-92a and miR-27b. In conclusion, mangiferin likely regulates proliferation and apoptosis in LUAD cells by reducing the expression levels of miR-92a and miR-27b.

Cation Lipid-Assisted PEG6-PLGA Polymer Nanoparticles Encapsulated Knocking Down Long ncRNAs Reverse Non-Coding RNA of Xist Through the Support Vector Machine Model to Regulate the Molecular Mechanisms of Gastric Cancer Cell Apoptosis

Gastric adenocarcinoma (GAC) is one kind of gastric cancer with a high incidence rate and mortality. It is essential to study the etiology of GAC and provide theoretical guidance for the prevention and treatment of GAC. Bioinformatics was used via differential expression analysis, weighted gene co-expression network analysis, gene set enrichment analysis, and a training support vector machine (SVM) model to construct a TSIX/mir-320a/Rad51 network as the research index of GAC disease. On the basis of CRISPR/Cas9 gene editing technology, the present study utilizes the Cation lipid-assisted PEG-6-PLGA polymer nanoparticle (CLAN) drug carrier system to prepare the target knock-out TSIX drug with CRISPR/CaS9 nucleic acid. Knocking down lncRNA TSIX restored the suppression role of miR-320a on Rad51 and inhibited the Rad51 expression. Simultaneously, this ceRNA network activated the ATF6 signaling pathway after endoplasmic reticulum stress to promote GAC cells' apoptosis and inhibit the disease. TSIX/miR-320a/Rad51 network may be a potential biological target of GAC disease and provides a new strategy for treating GAC disease.

A stable gene set for prediction of prognosis and efficacy of chemotherapy in gastric cancer

Background

Gastric cancer (GC) is a primary reason for cancer death in the world. At present, GC has become a public health issue urgently to be solved to. Prediction of prognosis is critical to the development of clinical treatment regimens. This work aimed to construct the stable gene set for guiding GC diagnosis and treatment in clinic.

Methods

A public microarray dataset of TCGA providing clinical information was obtained. Dimensionality reduction was carried out by selection operator regression on the stable prognostic genes discovered through the bootstrap approach as well as survival analysis.

Findings

A total of 2 prognostic models were built, respectively designated as stable gene risk scores of OS (SGRS-OS) and stable gene risk scores of PFI (SGRS-PFI) consisting of 18 and 21 genes. The SGRS set potently predicted the overall survival (OS) along with progression-free interval (PFI) by means of univariate as well as multivariate analysis, using the specific risk scores formula. Relative to the TNM classification system, the SGRS set exhibited apparently higher predicting ability. Moreover, it was suggested that, patients who had increased SGRS were associated with poor chemotherapeutic outcomes.

Interpretation

The SGRS set constructed in this study potentially serves as the efficient approach for predicting GC patient survival and guiding their treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08444-w.

MiR-421 Aggravates Neurotoxicity and Promotes Cell Death in Parkinson's Disease Models by Directly Targeting MEF2D

Parkinson's disease (PD) is a severe neurodegenerative disease characterized by selective loss of dopaminergic neurons, which reduces quality of life of patients and poses a heavy burden to the society. The pathological mechanism of PD remains unclear, and increasing efforts are aimed to solve this problem. MiRNAs are a kind of small noncoding RNA regulating target gene expression. Previous studies have shown that dysregulation of miRNAs is involved in the development of PD. In the present study, we determined that miR-421 and MEF2D are increased and decreased, respectively, in a cellular model of PD. The data on the mechanism of action indicate that miR-421 directly binds to MEF2D mRNA and negatively regulates MEF2D expression. An increase in miR-421 disrupted the Bcl2/Bax system. Functional assays indicated that enhanced miR-421 promotes cell death by negative modulation of MEF2D expression. Inhibition of miR-421 or restoration of MEF2D protected neurons from neurotoxicity in cellular and animal models of PD. Our study is the first to demonstrate that miR-421 is decreased in PD models and to determine a novel putative mechanism of PD pathogenesis.

Biased Influences of Low Tumor Purity on Mutation Detection in Cancer

The non-cancerous components in tumor tissues, e.g., infiltrating stromal cells and immune cells, dilute tumor purity and might confound genomic mutation profile analyses and the identification of pathological biomarkers. It is necessary to systematically evaluate the influence of tumor purity. Here, using public gastric cancer samples from The Cancer Genome Atlas (TCGA), we firstly showed that numbers of mutation, separately called by four algorithms, were significant positively correlated with tumor purities (all p < 0.05, Spearman rank correlation). Similar results were also observed in other nine cancers from TCGA. Notably, the result was further confirmed by six in-house samples from two gastric cancer patients and five in-house samples from two colorectal cancer patients with different tumor purities. Furthermore, the metastasis mechanism of gastric cancer may be incorrectly characterized as numbers of mutation and tumor purities of 248 lymph node metastatic (N + M0) samples were both significantly lower than those of 121 non-metastatic (N0M0) samples (p < 0.05, Wilcoxon rank-sum test). Similar phenomena were also observed that tumor purities could confound the analysis of histological subtypes of cancer and the identification of microsatellite instability status (MSI) in both gastric and colon cancer. Finally, we suggested that the higher tumor purity, such as above 70%, rather than 60%, could be better to meet the requirement of mutation calling. In conclusion, the influence of tumor purity on the genomic mutation profile and pathological analyses should be fully considered in the further study.

Effect of miR-27b-5p on apoptosis of human vascular endothelial cells induced by simulated microgravity

Weightlessness-induced cardiovascular dysfunction can lead to physiological and pathological consequences. It has been shown that spaceflight or simulated microgravity can alter expression profiles of some microRNAs (miRNAs). Here, we attempt to identify the role of miRNAs in human umbilical vein endothelial cells (HUVECs) apoptosis under simulated microgravity. RNA-sequencing and quantitative real-time PCR (qRT-PCR) assays were used to identify differentially expressed miRNAs in HUVECs under simulated microgravity. Then we obtained the target genes of these miRNAs through target analysis software. Moreover, GO and KEGG enrichment analysis were performed. The effects of these miRNAs on HUVECs apoptosis were evaluated by flow cytometry, Western blot and Hoechst staining. Furthermore, we obtained the target gene of miR-27b-5p by luciferase assay, qRT-PCR and Western blot. Finally, we investigated the relationship between this target gene and miR-27b-5p in HUVECs apoptosis under normal gravity or simulated microgravity. We found 29 differentially expressed miRNAs in HUVECs under simulated microgravity. Of them, the expressions of 3 miRNAs were validated by qRT-PCR. We demonstrated that miR-27b-5p affected HUVECs apoptosis by inhibiting zinc fingers and homeoboxes 1 (ZHX1). Our results reported here demonstrate for the first time that simulated microgravity can alter the expression of some miRNAs in HUVECs and miR-27b-5p may protect HUVECs from apoptosis under simulated microgravity by targeting ZHX1.

Targeting of KDM5A by miR-421 in Human Ovarian Cancer Suppresses the Progression of Ovarian Cancer Cells

PURPOSE

The retinoblastoma binding protein RBP2 (KDM5A) is a histone demethylase that promotes cell growth in many human cancers. A series of functional experiments were conducted to explore the role of miR-421/KDM5A in ovarian cancer cells and their underlying molecular mechanisms.

MATERIALS AND METHODS

Public microarray databases were analyzed to assess KDM5A and miR-421 expression in ovarian cancer. KDM5A was predicted to be a target of miR-421 using software analysis. The expression of the miR-421/KDM5A regulatory axis in ovarian cancer and the mechanisms of its effects on proliferation, migration, and invasion of ovarian cancer cell lines were investigated.

RESULTS

Compared with normal ovarian tissues, the expression of KDM5A mRNA and protein was elevated (P<0.05), and miR-421 expression was reduced in ovarian cancer tissue (P<0.05). miR-421 was found to bind specifically to the KDM5A gene. Silencing KDM5A or overexpressing miR-421 significantly inhibited proliferation, migration, and invasion of OVCAR-8 and SKOV-3 cells. Similarly, compared with nude mice injected with cells transfected with empty capsids, the in vivo proliferation rate of OVCAR-8 cells after miR-421 overexpression was reduced significantly.

CONCLUSION

The miR-421/KDM5A regulatory axis plays an important role in the development and progression of ovarian cancer cells.

Small RNAs, Big Diseases

The past two decades have seen extensive research done to pinpoint the role of microRNAs (miRNAs) that have led to discovering thousands of miRNAs in humans. It is not, therefore, surprising to see many of them implicated in a number of common as well as rare human diseases. In this review article, we summarize the progress in our understanding of miRNA-related research in conjunction with different types of cancers and neurodegenerative diseases, as well as their potential in generating more reliable diagnostic and therapeutic approaches.

Changes of miRNA Expression Profiles from Cervical-Vaginal Fluid-Derived Exosomes in Response to HPV16 Infection

As an oncogenic virus, HPV16 can lead to the dysfunction of cervical epithelial cells and contribute to the progression of cervical cancer. Components from the cervical-vaginal fluid (CVF) could be used as the basis for cervical cancer screening. Exosomes are widely present in various body fluids and participate in intercellular communication via its cargos of proteins, mRNAs, and miRNAs. This study was conducted to explore the changes of miRNAs in exosomes isolated form the cervical-vaginal fluid during HPV16 infection and to predict the potential effects of exosomal miRNAs on the development of cervical cancer. CVF was collected from volunteers with or without HPV16 infection. The exosomes in CVF were identified by electron microscopy. Microarray analysis was subjected to find the differentially expressed miRNAs in CVF exosomes. To confirm the results, 16 miRNAs were randomly selected to go through real-time quantitative polymerase chain reaction. In addition, GO and pathway analyses were conducted to reveal potential functions of differentially expressed miRNAs. A total of 2548 conserved miRNAs were identified in the cervical-vaginal fluid-derived exosomes. In response to HPV16 infection, 45 miRNAs are significantly upregulated and 55 miRNAs are significantly downregulated (P < 0.05). The GO and KEGG pathway analyses revealed that these differentially expressed miRNAs are tightly associated with cervical cancer tumorigenesis, through interaction with the Notch signaling pathway, TNF signaling pathway, and TGF-β signaling pathway. These results suggest that exosomal miRNAs in CVF are differentially expressed in HPV16 infection patients and HPV16-free volunteers. It provided a novel insight to understand the underlying mechanism of HPV16 infection in regulating cervical cancer progression.

Effects of p-coumaric acid on microRNA expression profiles in SNU-16 human gastric cancer cells

BACKGROUND

p-Coumaric acid (p-CA), a phenolic compound abundantly found in edible plants, was found to induce apoptosis in SNU-16 gastric cancer cells. However, the effects of p-CA on the microRNA expression pattern in SNU-16 cells have not been reported.

OBJECTIVES

The primary objective of this study was to investigate microRNA expression profiles in p-CA-treated SNU-16 cells.

METHODS

SNU-16 cells were treated with 1.5 mM p-CA for 48 h. High-throughput RNA sequencing was performed. The accuracy and validity of the RNA sequencing results were tested by real-time PCR. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed using the differentially expressed microRNAs (DEMs).

RESULTS

Thirty-two DEMs were identified between p-CA-treated and control cells, 9 of which were upregulated, and 23 downregulated. GO and KEGG pathway analyses of the target genes indicated that these genes were involved in a variety of biological functions and several cancer-related pathways. The miRNA interactive network analysis identified hsa-miR-125a-5p, hsa-miR-30a-5p, and hsa-miR-7-5p as the major nodes.

CONCLUSIONS

Our findings indicated that p-CA exerted its anticancer effects in SNU-16 gastric cancer cells by modulating the expression of certain microRNAs, providing a better understanding of the anticancer properties of p-CA in gastric cancer cells.

Novel Broccoli Sulforaphane-Based Analogues Inhibit the Progression of Pancreatic Cancer without Side Effects

The naturally occurring isothiocyanate sulforaphane, found in Brassicaceae vegetables, is promising in cancer treatment, e.g., by the normalization of enhanced levels of NF-κB-signaling in tumor stem cells. We chemically synthesized seven sulforaphane analogues by substitution of the sulfinyl group (S(O)) to either sulfimidoyl (S(NR)) or sulfonimidoyl (S (O) (NR)) groups, and characterized them in the cell lines of pancreatic cancer and several other tumor entities, including the NCI-60 cell panel. MTT and colony forming assays, flow cytometry, immunohistochemistry, microRNA arrays, bioinformatics, tumor xenotransplantation, and Kaplan Meier survival curves were performed. Compared to sulforaphane, the analogue SF102 was most efficient in inhibition of viability, colony formation, tumor growth, and the induction of apoptosis, followed by SF134. Side effects were not observed, as concluded from the body weight and liver histology of chick embryos and survival of C. elegans nematodes. Among 6659 differentially regulated microRNAs, miR29b-1-5p, and miR-27b-5p were downregulated by sulforaphane compared to controls, but upregulated by SF102 and SF134 compared to sulforaphane, suggesting differential signaling. Each substance was involved in the regulation of several NF-κB-related target genes. In conclusion, sulforaphane analogues are promising for the development of highly active new drugs in cancer treatment.

Integrated analysis of a lncRNA‑mRNA network reveals a potential mechanism underlying necrotizing enterocolitis

Previous studies have shown that long non-coding RNAs (lncRNAs) serve important roles in necrotizing enterocolitis (NEC). However, the underlying mechanisms remain largely unknown. In order to examine the potential role of lncRNAs in NEC, the present study investigated lncRNA and mRNA expression profiles in NEC lesions and adjacent intestinal tissues using Next Generation Sequencing. A total of 4,202 differentially expressed lncRNAs (fold-change >2; P<0.05) and 7,860 differentially expressed mRNAs (fold-change >2; P<0.05) were identified. Moreover, 5 dysregulated lncRNAs and 5 mRNAs were randomly selected, and further assessed by reverse transcription-quantitative PCR in vitro. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses demonstrated that the differentially expressed lncRNAs were closely associated with NEC, and were enriched in ‘inflammatory response’, ‘Toll-like receptor binding’, ‘PPAR signaling pathway’, ‘PI3K-Akt signaling pathway’, ‘transforming growth factor-β signaling pathway’ and ‘hypoxia-inducible factor 1 signaling pathway’. In addition, co-expression analysis demonstrated that these lncRNAs, including lncRNA ENST00000623580, lncRNA NONHSAT180418.1, lncRNA NONHSAT125636.2 and NONHSAT087855.2, may mediate the pathogenesis and development of NEC via lncRNA-mRNA network interactions. Therefore, the present study provided a novel insight into the role of lncRNAs in NEC.

MicroRNA hsa-mir-3923 serves as a diagnostic and prognostic biomarker for gastric carcinoma

Gastric carcinoma (GC) refers to a common digestive system disease that exhibits a very high incidence. MicroRNA hsa-mir-3923 belongs to a type of miRNA, of which the function has been merely investigated in breast, pancreatic cancers and pre-neoplasic stages of gastric cancer. It has not been studied or reported in gastric carcinoma, so the relationship between gastric hsa-mir-3923 expression and the clinics feature and pathology of GC cases was examined. This study employed data mining for analyzing gastric carcinoma data in The Cancer Genome Atlas database. A Chi squared test was performed for assessing the relations of hsa-mir-3923 expression with clinics-related and pathology-regulated variables. This study conducted the assessment of the role of hsa-mir-3923 in prognostic process using Kaplan-Meier curves, Receiver operating characteristic (ROC) analysis and proportional hazards model (Cox) study. With the use of Gene Expression Omnibus, this study carried out gene set enrichment analysis (GSEA). In the meantime, the common miRNA database was compared to predict potential target genes; as revealed by co-expression analysis, a regulatory network probably existed, containing hsa-mir-3923. For the analysis of the most tightly associated cytological behavior and pathway in GC, this study adopted the databases for Annotation, Visualization and Integrated Discovery (David) and KO-Based Annotation System (KOBAS). Cytoscape, R and STRING were employed for mapping probable regulatory networks displaying relations to hsa-mir-3923. Lastly, we obtained 69 genes most tightly associated with hsa-mir-3923 and described their relationship with Circos plot. As revealed from the results, hsa-mir-3923 displayed up-regulation in gastric carcinoma, and it displayed associations with vital status, N stage and histologic grade when being expressed. The predicted results of miRNA target genes suggested that there may be a close relationship between 66 genes and hsa-mir-3923 in gastric cancer. As indicated from co-expression data, a small regulating network of 4 genes probably existed. Our results elucidated that hsa-mir-3923 high-expression reveals poor prognosis of GC patients.

LINC01436, regulating miR-585 and FBXO11, is an oncogenic lncRNA in the progression of gastric cancer

Accumulating studies have indicated that long non-coding RNAs (lncRNAs) are crucial modulators in cancer biology. In this work, we investigated the function and related mechanisms of LINC01436 in the progression of gastric cancer (GC). We demonstrated that LINC01436 was significantly up-regulated in cancerous tissues of GC samples, and its overexpression was correlated with a worse prognosis for the patients. In the GC cell line BGC823 cells, LINC01436 knockdown repressed the proliferation and metastasis of cancer cells; conversely, in GC cell line AGS cells, overexpression of LINC01436 showed the opposite effects. We then demonstrated that miR-585, a tumor suppressor, could bind to both LINC01436 and the 3'-UTR of F-box protein 11 (FBOX11), and LINC01436 was proved to sponge miR-585 and repress it, and indirectly promoted the expression of FBOX11. Collectively, these results suggested that LINC01436 was an oncogenic lncRNA in GC and promoted proliferation and metastasis of GC cell via regulating miR-585 and FBOX11.

miRNAs as potential biomarkers for the progression of gastric cancer inhibit CREBZF and regulate migration of gastric adenocarcinoma cells

In our previous study, we identified three miRNAs (hsa-miR-421, hsa-miR-29b-1-5p, and hsa-miR-27b-5p) with two mRNAs (FBXO11 and CREBZF) that might play an important role in the development of gastric adenocarcinoma (GAC) from premalignant adenomas. However, the expression and function of these miRNAs have not been not well characterized. We investigated the roles of CREBZF and miRNAs as potential biomarkers for the progression of gastric cancer (GC) in low-/high-grade dysplasia and early gastric cancer patients using immunohistochemical staining and miRNA in situ hybridization. Considering that targets can modulate in GC, we analyzed the CREBZF expression in gastric cancer cell lines by RT-PCR and western blot analysis. We observed lower expression of CREBZF with increasing miRNAs in the MKN-74 gastric cancer cells compared to that in SNU-NCC-19. Next, the role of CREBZF in MKN-74 gastric cancer cells was investigated via cell viability and migration assays by miRNA/anti-miRNA modulation. Furthermore, we found that hsa-miR-421/hsa-miR-29b-1-5p target CREBZF and might play an important role in the migration of MKN-74 cells. This study suggests that increased CREBZF by hsa-miR-421/hsa-miR-29b-1-5p inhibition may be important to prevent the progression of gastric cancer in its early stage.

The Oncogenic Activity of miR-29b-1-5p Induces the Epithelial-Mesenchymal Transition in Oral Squamous Cell Carcinoma

Background: The relationship between miR-29b-1-5p and c-Met proto-oncogene in oral squamous cell carcinoma (OSCC) remains to be investigated. This study aimed to reveal the role of miR-29b-1-5p in the pathogenesis of OSCC using molecular and biological analyses. Methods: We investigated the expression of miR-29b-1-5p, c-Met, and markers of the epithelial-mesenchymal transition (EMT) in the tissues of 49 patients with OSCC and in human OSCC cells with different tumorigenicity. Further, we determined the effects of miR-29b-1-5p on the phenotypes of OSCC cell lines. Results: The expression levels of miR-29b-1-5p in most patients with OSCC were higher than those of the normal oral epithelium. In OSCC, upregulation of miR-29b-1-5p significantly correlated with histological grade, the EMT, and the immunohistochemical grade, indicated by c-Met expression. The prognosis was poor for patients with miR-29b-1-5p expression and coexpression of miR-29b-1-5p and c-Met. In OSCC cells exhibiting the EMT phenotype, knockdown of miR-29b-1-5p suppressed the EMT, which was recovered by enforced expression of c-Met. Further, the mRNA encoding cadherin 1 (CDH1) was a direct target of miR-29b-1-5p. Conclusions: Our results suggest that miR-29b-1-5p acts as an oncogenic miRNA that synergizes with c-Met to induce the EMT of OSCC cells.