MiR-214 inhibits the proliferation and invasion of esophageal squamous cell carcinoma cells by targeting CDC25B

Tumor microenvironment biomarkers predicting pathological response to neoadjuvant chemoimmunotherapy in locally advanced esophageal squamous cell carcinoma: post-hoc analysis of a single center, phase 2 study

BACKGROUND

Neoadjuvant chemoimmunotherapy has a promising effect on locally advanced esophageal squamous cell carcinoma (ESCC). However, reliable biomarkers robustly predicting therapeutic response are still lacking.

METHODS

Formalin-fixed and paraffin-embedded pre-neoadjuvant chemoimmunotherapy biopsy samples from locally advanced ESCC patients were collected. Cohort 1 composed of 66 locally advanced ESCC patients from a prospective clinical trial (NCT04506138) received two cycles of camrelizumab in combination with nab-paclitaxel and carboplatin every 3 weeks. Cohort 2 included 48 patients receiving various types of immune checkpoint inhibitors with (nab-)paclitaxel and platinum-based chemotherapy as neoadjuvant therapy. Cohort 3 consisted of 27 ESCC patients receiving neoadjuvant treatment of toripalimab with chemotherapy and was used as the external validation dataset. Targeted RNA sequencing, immunohistochemistry for programmed death ligand 1 (PD-L1), and multiplex immunofluorescence (mIF) imaging were performed.

RESULTS

Integration of targeted RNA sequencing, PD-L1 immunohistochemistry, and mIF revealed a significant immune-suppressive microenvironment with higher neutrophil infiltration, enriched TGF-β, and cell cycle pathways in non-pathological complete response (non-pCR) patients. NK, activated CD4+ T cell infiltration, interferon-gamma, antigen processing and presentation, and other immune response signatures were significantly associated with pCR. Based on discovered tumor microenvironmental characteristics and their closely related genes were screened. Consequently, a seven-gene neoadjuvant chemoimmunotherapy risk prediction signature (NCIRPs) model, was constructed. In addition to cohort 1, this model alone or with PD-L1-combined positive score (CPS) demonstrated a higher prediction accuracy of pathological response than PD-L1 CPS or other routinely used immune signatures, such as IFN-γ, in cohorts 2 and 3. Neither prognostic association nor correlation with response to chemoradiotherapy was observed in The Cancer Genome Atlas Program ESCC dataset or in ESCC patients in the neoadjuvant chemoradiotherapy cohort (cohort 4).

CONCLUSION

The NCIRPs model that was developed and validated using treatment-naïve endoscopic samples from the largest ESCC neoadjuvant chemoimmunotherapy dataset represents a robust and clinically meaningful approach to select a putative responder for neoadjuvant chemoimmunotherapy in locally advanced ESCC patients.

MicroRNAs: A novel signature in the metastasis of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a malignant epithelial tumor, characterized by squamous cell differentiation, it is the sixth leading cause of cancer-related deaths globally. The increased mortality rate of ESCC patients is predominantly due to the advanced stage of the disease when discovered, coupled with higher risk of metastasis, which is an exceedingly malignant characteristic of cancer, frequently leading to a high mortality rate. Unfortunately, there is currently no specific and effective marker to predict and treat metastasis in ESCC. MicroRNAs (miRNAs) are a class of small non-coding RNA molecules, approximately 22 nucleotides in length. miRNAs are vital in modulating gene expression and serve pivotal regulatory roles in the occurrence, progression, and prognosis of cancer. Here, we have examined the literature to highlight the intimate correlations between miRNAs and ESCC metastasis, and show that ESCC metastasis is predominantly regulated or regulated by genetic and epigenetic factors. This review proposes a potential role for miRNAs as diagnostic and therapeutic biomarkers for metastasis in ESCC metastasis, with the ultimate aim of reducing the mortality rate among patients with ESCC.

MiR-214-3p targets Ras-related protein 14 (RAB14) to inhibit cellular migration and invasion in esophageal Cancer cells

BACKGROUND

MicroRNA (miR)-214-3p is emerging as an important tumor suppressor in esophageal cancer. In this study, we examined the interaction between miR-214-3p and RAB14, a membrane trafficking protein shown to exert oncogenic functions in other malignancies, in esophageal cancer cells.

METHODS

Studies were performed in a human esophageal epithelial cell line and a panel of esophageal cancer cell lines, as well in human specimens. MiR-214-3p expression was measured by digital PCR. Biotinylated RNA pull-down and luciferase reporter assays assessed binding. The xCELLigence RTCA system measured cell migration and invasion in real time. A lentiviral expression vector was used to create an esophageal cancer cell line stably expressing miR-214-3p.

RESULTS

MiR-214-3p expression was decreased in esophageal cancer cell lines and human specimens compared to non-malignant controls. RAB14 mRNA stability and protein expression were decreased following miR-214-3p overexpression. Binding between miR-214-3p and RAB14 mRNA was observed. Either forced expression of miR-214-3p or RAB14 silencing led to a marked decrease in cellular migration and invasion. Esophageal cancer cells stably expressing miR-214-3p demonstrated decreased growth in a subcutaneous murine model.

CONCLUSIONS

These results further support the tumor-suppressive role of miR-214-3p in esophageal cancer cells by demonstrating its ability to regulate RAB14 expression.

Effect of miR-214 on Proliferation, Cell Cycle and Apoptosis of Esophageal Cancer Cells

Esophageal cancer seriously affects human health. miR-214 involves in esophageal cancer, but its specific mechanism has not been completely elucidated. Our study investigated miR-214’s role in esophageal cancer. Eca109 cells were transfected with miR-214 inhibitor/NC was transfected into Eca109 cells followed by analysis of miR-214 level by real-time PCR, cell proliferation by CCK8 assay, cell apoptosis and cell cycle and PTEN level by Western blot. miR-214 was significantly upregulated in Eca109 cells (P < 0.01) with downregulated PTEN (P < 0.05). miR-214 inhibitor significantly upregulated PTEN, decreased cell number, increased apoptosis and cells in G1 phase (P < 0.05). PTEN was a target of miR-214. miR-214 affects esophageal cancer cells by targeting PTEN.

LncRNA FAM83A-AS1 promotes ESCC progression by regulating miR-214/CDC25B axis

Background: Recent researches have pinpointed that long non-coding RNA (lncRNA) was tightly related to the carcinogenesis. However, the function of lncRNA in esophageal cell squamous carcinoma (ESCC) remains to be explored. In the current study, we assessed the expression pattern and the biological function of FAM83A-AS1 in ESCC.

Methods: qRT-PCR was used to detect the expression of FAM83A-AS1, miR-214, and CDC25B expression in ESCC tissues and cell lines. CCK-8, transwell, apoptosis and cell cycle assays were performed to define the function of FAM83A-AS1 in ESCC cells. Furthermore, the regulation of miR-214 by FAM83A-AS1 was defined by qRT- PCR and rescue assays. In addition, the association between CDC25B, miR-214, CDC25B was confirmed by qRT-PCR.

Results: Here, we discovered that FAM83A-AS1 was strongly expressed in ESCC tissues. FAM83A-AS1 abundance was associated with TNM stages and the differentiation grade of ESCC patients. The receiver operating characteristic curve (ROC) analysis indicated the high accuracy of FAM83A-AS1 in ESCC diagnosis. Functionally, inhibiting FAM83A-AS1 repressed cell proliferation, migration, and invasion in ESCC. In addition, we found that FAM83A-AS1 accelerated the cell cycle while inhibited cell apoptosis. Mechanistically, we found that FAM83A-AS1 regulated miR-214 expression, and there was a negative correlation between miR-214 and FAM83A-AS1 in ESCC. Rescue assay indicated that miR-214 could impair the suppressing effect of cell migration induced by FAM83A-AS1 depletion. Furthermore, CDC25B was a direct target of miR-214, and FAM83A-AS1 enhanced CDC25B expression while miR-214 positively CDC25B expression in ESCC.

Conclusions: Collectively, we concluded that FAM83A-AS1 facilitated ESCC progression by regulating the miR-214/CDC25B axis. Our study showed FAM83A-AS1 may act as a promising target for ESCC diagnosis and therapy.

LncRNA MIR205HG Drives Esophageal Squamous Cell Carcinoma Progression by Regulating miR-214/SOX4 Axis

Background

Esophageal squamous cell carcinoma (ESCC) is a common and fatal malignancy, which has posed a great challenge to public health, especially in China. Dysregulation of long non-coding RNAs is involved in the occurrence, development, invasion, and metastasis of multiple cancers including ESCC. However, little is known about the function of MIR205HG in ESCC.

Methods

We used qRT-PCR to detect the expression level of MIR205HG, miR-214, and SOX4 in human ESCC tissues and cell lines. Loss-of-functional assays were performed to test the impact of MIR205HG on cell proliferation, metastasis, and apoptosis process via CCK-8, transwell, and flow cell cytometry assays. Additionally, the downstream molecular mechanism of MIR205HG in ESCC was explored.

Results

Here, we found MIR205HG was substantially up-regulated in ESCC, and there was a positive correlation between MIR205HG expression and tumor size and lymphatic metastasis of ESCC patients. Inhibition of MIR205HG attenuated cell proliferation, migration, and invasion. Silencing MIR205HG increased G1 phase cell counts and decreased S phase cell counts, along with increased apoptotic cell populations. Notably, the rescue assays indicated that miR-214 could partly reverse the influence of MIR205HG on ESCC cell migration. We also found that SOX4 was a direct target mRNA of miR-214, and MIR205HG could act as a molecular sponge to regulate SOX4 expression in ESCC.

Conclusion

Taken together, our findings demonstrate that MIR205HG promotes ESCC progression by regulating the miR-214/SOX4 axis. MIR205HG may be a novel candidate target for ESCC diagnosis and therapy.

Regulators at Every Step-How microRNAs Drive Tumor Cell Invasiveness and Metastasis

Tumor cell invasiveness and metastasis are the main causes of mortality in cancer. Tumor progression is composed of many steps, including primary tumor growth, local invasion, intravasation, survival in the circulation, pre-metastatic niche formation, and metastasis. All these steps are strictly controlled by microRNAs (miRNAs), small non-coding RNA that regulate gene expression at the post-transcriptional level. miRNAs can act as oncomiRs that promote tumor cell invasion and metastasis or as tumor suppressor miRNAs that inhibit tumor progression. These miRNAs regulate the actin cytoskeleton, the expression of extracellular matrix (ECM) receptors including integrins and ECM-remodeling enzymes comprising matrix metalloproteinases (MMPs), and regulate epithelial-mesenchymal transition (EMT), hence modulating cell migration and invasiveness. Moreover, miRNAs regulate angiogenesis, the formation of a pre-metastatic niche, and metastasis. Thus, miRNAs are biomarkers of metastases as well as promising targets of therapy. In this review, we comprehensively describe the role of various miRNAs in tumor cell migration, invasion, and metastasis.

Regulators at Every Step—How microRNAs Drive Tumor Cell Invasiveness and Metastasis

Tumor cell invasiveness and metastasis are the main causes of mortality in cancer. Tumor progression is composed of many steps, including primary tumor growth, local invasion, intravasation, survival in the circulation, pre-metastatic niche formation, and metastasis. All these steps are strictly controlled by microRNAs (miRNAs), small non-coding RNA that regulate gene expression at the post-transcriptional level. miRNAs can act as oncomiRs that promote tumor cell invasion and metastasis or as tumor suppressor miRNAs that inhibit tumor progression. These miRNAs regulate the actin cytoskeleton, the expression of extracellular matrix (ECM) receptors including integrins and ECM-remodeling enzymes comprising matrix metalloproteinases (MMPs), and regulate epithelial–mesenchymal transition (EMT), hence modulating cell migration and invasiveness. Moreover, miRNAs regulate angiogenesis, the formation of a pre-metastatic niche, and metastasis. Thus, miRNAs are biomarkers of metastases as well as promising targets of therapy. In this review, we comprehensively describe the role of various miRNAs in tumor cell migration, invasion, and metastasis.

A Loop-Based and AGO-Incorporated Virtual Screening Model Targeting AGO-Mediated miRNA-mRNA Interactions for Drug Discovery to Rescue Bone Phenotype in Genetically Modified Mice

Several virtual screening models are proposed to screen small molecules only targeting primary miRNAs without selectivity. Few attempts have been made to develop virtual screening strategies for discovering small molecules targeting mature miRNAs. Mature miRNAs and their specific target mRNA can form unique functional loops during argonaute (AGO)-mediated miRNA-mRNA interactions, which may serve as potential targets for small-molecule drug discovery. Thus, a loop-based and AGO-incorporated virtual screening model is constructed for targeting the loops. The previously published studies have found that miR-214 can target ATF4 to inhibit osteoblastic bone formation, whereas miR-214 can target TRAF3 to promote osteoclast activity. By using the virtual model, the top ten candidate small molecules targeting miR-214-ATF4 mRNA interactions and top ten candidate small molecules targeting miR-214-TRAF3 mRNA interactions are selected, respectively. Based on both in vitro and in vivo data, one small molecule can target miR-214-ATF4 mRNA to promote ATF4 protein expression and enhance osteogenic potential, whereas one small molecule can target miR-214-TRAF3 mRNA to promote TRAF3 protein expression and inhibit osteoclast activity. These data indicate that the loop-based and AGO-incorporated virtual screening model can help to obtain small molecules specifically targeting miRNA-mRNA interactions to rescue bone phenotype in genetically modified mice.

Loss of miR-204-5p Promotes Tumor Proliferation, Migration, and Invasion Through Targeting YWHAZ/PI3K/AKT Pathway in Esophageal Squamous Cell Carcinoma

PURPOSE

MicroRNAs dysregulation has been confirmed in multiple malignancies. This paper reported the molecular mechanism of miR-204-5p in esophageal squamous cell carcinoma (ESCC).

METHODS

miR-204-5p expression in 30 ESCC tumor tissues and 10 normal tissues was downloaded from RNA-seq data. ESCC tissues/normal tissues of 97 ESCC patients were collected. TE-1 and KYSE510 cells were transfected by miR-204-5p mimic, inhibitor, siYWHAZ or their corresponding controls. The phenotype of cells was detected by CCK-8 assay, transwell experiment, and flow cytometry. Luciferase reporter gene assay and RNA-binding protein immunoprecipitation (RIP) were performed to verify the targeting relationship between miR-204-5p and YWHAZ. miR-204-5p and YWHAZ expression in tissues/cells was detected by qRT-PCR and Western blot. Xenograft tumor experiment was performed.

RESULTS

miR-204-5p expression was declined in ESCC patients and cells, which was indicated the poor outcome of patients. Compared with siNC group, TE-1 cells in miR-204-5p inhibitor group had higher OD450 value, less cell percentage in G1 phase, and more cell percentage in S phase, lower apoptosis percentage, and higher migration and invasion cell numbers. Moreover, KYSE510 cells of miR-204-5p mimic group showed lower OD450 value, more cell percentage in G1 phase and less cell percentage in S phase, higher apoptosis percentage, and lower migration and invasion cell numbers than control. YWHAZ was directly inhibited by miR-204-5p. Relative to siNC group, TE-1 cells of miR-inhibitor group exhibited higher YWHAZ protein expression, higher OD450 value, less cell percentage in G1 phase and more cell percentage in S phase, lower apoptosis percentage, higher migration and invasion cell numbers, and higher p-PI3K/PI3K and p-AKT/AKT protein expression, while siYWHAZ rescued the effects of miR-inhibitor. miR-204-5p up-regulation inhibited ESCC growth in vivo.

CONCLUSION

miR-204-5p inhibits ESCC progression by targeted inhibition of YWHAZ/PI3K/AKT.

MicroRNA-129-5p represses the growth and aggressiveness of oral squamous cell carcinoma via suppressing HMGB1

Recent investigations have suggested that microRNA-129-5p (miR-129-5p) is commonly dysregulated in multiple types of malignancies. Nevertheless, the roles of miR-129-5p in human oral squamous cell carcinoma (OSCC) are not well explored. Herein, we demonstrated that miR-129-5p was down-expressed in OSCC cells and tissues. Moreover, miR-129-5p overexpression restrained the growth, migration ability, and invasiveness of OSCC cells. Notably, high-mobility group box 1 protein (HMGB1) was identified as a downstream target of miR-129-5p. Additional, knockdown of HMGB1 suppressed the growth and aggressive phenotypes of human OSCC cells. Importantly, re-expression of HMGB1 impaired the inhibitory impacts of miR-129-5p on the metastasis of OSCC cells. Altogether, these results implied that miR-129-5p restrained the aggressiveness of OSCC cells through modulating HMGB1.

Non-coding RNA LOXL1-AS1 exhibits oncogenic activity in ovarian cancer via regulation of miR-18b-5p/VMA21 axis

Long non-coding RNAs (lncRNAs) exert critical effects in the process of malignant cancers and lncRNA LOXL1 Antisense RNA 1 (LOXL1-AS1) has been demonstrated to be a pro-oncogene in multiple tumor types. In the current study, we illuminated the precise roles of LOXL1-AS1 in the development of ovarian cancer. LOXL1-AS1 is significantly overexpressed in ovarian carcinoma tissue compared with adjacent non-cancerous sample. The luciferase reporter gene assay reveals the relationship between LOXL1-AS1 and miR-18b-5p, miR-18b-5p and its target gene, Vacuolar ATPase Assembly Factor VMA21 (VMA21). Transfection of LOXL1-AS1 siRNA or miR-18b-5p mimics inhibits the growth and aggressive phenotypes of SKOV3 and OVCAR3 cell. Furthermore, miR-18b-5p suppresses ovarian carcinoma cell proliferation and metastasis by targeting VMA21 and LOXL1-AS1 regulates ovarian carcinoma cell growth and metastasis through sponging miR-18b-5p. These findings suggest that lncRNA LOXL1-AS1 promotes ovarian cancer cell growth, migratory and invasiveness via modulating miR-18b-5p/VMA21 axis.

MicroRNA-214 suppresses cell proliferation and migration and cell metabolism by targeting PDK2 and PHF6 in hepatocellular carcinoma

MiR-214 has been reported to act as a tumor suppressor or oncogene involved in various malignancies. However, the biological functions and molecular mechanisms of miR-214 in hepatocellular carcinoma (HCC) still remain unclear. Previous studies suggest that pyruvate dehydrogenase kinase 2 (PDK2) and plant homeodomain finger protein 6 (PHF6) may be involved in some tumor cell proliferation and migration. Therefore, we studied the relationship between PDK2/PHF6 and miR-214. The expression of miR-214, PDK2, and PHF6 was determined by quantitative real-time polymerase chain reaction in HCC tissues and cell lines. The Luciferase reporter assay was used to confirm the interaction between miR-214 and PDK2/PHF6. Cell proliferation, apoptosis, and migration were evaluated by cell counting kit-8 assay, flow cytometry, and transwell assay, respectively. The expressions levels of α-smooth muscle actin (α-SMA) and E-cadherin were detected via immunofluorescence assay. Here, we found that the expression of miR-214 decreased in HCC and was negatively correlated with PDK2 and PHF6. Moreover, PDK2 and PHF6 were the direct targets of miR-214 in HCC cells. Functional analysis showed that knockdown of PDK2 or PHF6 as well as miR-214 overexpression significantly suppressed cell proliferation and migration in HCC cells. Furthermore, we found that the suppression of cell proliferation and migration through PDK2 or PHF6 knockdown could be partially reversed by miR-214 down-regulation. Moreover, we demonstrated a decrease of mesenchymal cell marker α-SMA and increase of the epithelial marker E-cadherin after miR-214 overexpression, PDK2 knockdown or PHF6 knockdown, respectively, which also suggested that cell proliferation and migration were suppressed. Additionally, lactate and pyruvic acid production experiments confirmed miR-214 could suppress the HCC cell lactate and pyruvic acid levels by down-regulating PDK2/PHF6. In conclusion, MiR-214 may act as a tumor suppressor gene, presenting its suppressive role in cell proliferation and migration of HCC cells by targeting PDK2 and PHF6, and might provide a potential therapy target for patients with HCC.

miR-214-3p inhibits epithelial-to-mesenchymal transition and metastasis of endometrial cancer cells by targeting TWIST1

BACKGROUND

Substantive studies have described the ectopic microRNAs as a determinant of the pathogenesis of endometrial cancer (EC). miR-214-3p has been reported to be significantly downregulated in EC tissues, and its overexpression has been shown to inhibit the proliferation, migration, and invasion of EC cells. Our study sought to explore the molecular mechanism underlying the inhibitory effect of miR-214-3p on metastasis of EC cells.

METHODS

The expressions of miR-214-3p and TWIST1 in EC tissues and cells were detected by quantitative real-time PCR. Cell migration, invasion, and epithelial-to-mesenchymal transition (EMT) were measured by transwell and Western blot analyses, respectively. The interaction between miR-214-3p and TWIST1 was confirmed by luciferase reporter assay. Xenograft tumor assay was performed to verify the role and underlying mechanism of miR-214-3p in EC in vivo.

RESULTS

miR-214-3p was downregulated and TWIST1 was upregulated in EC tissues and cells. miR-214-3p was negatively correlated with TWIST1 expression in EC tissues. Overexpression of miR-214-3p suppressed migration, invasion, and EMT in EC cells. TWIST1 was identified as a target of miR-214-3p in EC cells, and its overexpression significantly restored the inhibitory effects of miR-214-3p on cell migration, invasion, and EMT while its knockdown remarkably abolished miR-214-3p inhibitor-mediated promotion of progression of EC cells. Additionally, addition of miR-214-3p inhibited tumor growth by regulating EMT in vivo.

CONCLUSION

miR-214-3p suppressed the EMT and metastasis of EC cells by targeting TWIST1, providing a novel biomarker for treatment of EC.

An alcohol-soluble polysaccharide from Atractylodes macrocephala Koidz induces apoptosis of Eca-109 cells

In this study, polysaccharides from Atractylodes macrocephala Koidz (APA) which were soluble in alcohol were prepared, purified, analyzed the structure and investigated the antitumor activity in vitro cell experiment. Results of high-performance gel permeation chromatography (HPGPC), fourier-transform infrared spectroscopy (FT-IR), and gas chromatography (GC) showed that APA was a 2.1KDa neutral hetero polysaccharide composed of arabinose and glucose (molar ratio, 1.00:4.57) with pyranose rings and α-type and β-type glycosidic linkages. Results by MTT experiments showed that the proliferation inhibition was 74.63% in Eca109 cells treated with 2 mg/mL dose of APA. Annexin V/PI assay, Hoechst 33,258 staining, cell cycle distribution, rhodamine 123 dye assay and western blot assay clarified that APA could accelerate the apoptosis of Eca109 cells by mitochondrial pathway and stocked cells at S phase. These data indicated that APA is a promising potential candidate for therapeutic treatment of esophageal cancer.

Long non-coding RNA LINC01535 promotes cervical cancer progression via targeting the miR-214/EZH2 feedback loop

Long non‐coding RNAs (lncRNAs) have shown critical roles in multiple cancers via competitively binding common microRNAs. miR‐214 has been proved to play tumour suppressive roles in various cancers, including cervical cancer. In this study, we identified that lncRNA LINC01535 physically binds miR‐214, relieves the repressive roles of miR‐214 on its target EZH2, and therefore up‐regulates EZH2 protein expression. Intriguingly, we also found that EZH2 directly represses the expression of miR‐214. Thus, miR‐214 and EZH2 form double negative regulatory loop. Through up‐regulating EZH2, LINC01535 further represses miR‐214 expression. Functional experiments showed that enhanced expression of LINC01535 promotes cervical cancer cell growth, migration and invasion in vitro and cervical cancer xenograft growth in vivo. Reciprocally, LINC01535 knockdown suppresses cervical cancer cell growth, migration and invasion. Activation of the miR‐214/EZH2 regulatory loop by overexpression of miR‐214 or silencing of EZH2 reverses the roles of LINC01535 in promoting cervical canc`er cell growth, migration and invasion in vitro and cervical cancer xenograft growth in vivo. Clinically, LINC01535 is significantly up‐regulated in cervical cancer tissues and correlated with advanced clinical stage and poor prognosis. Moreover, the expression of LINC01535 is reversely associated with the expression of miR‐214 and positively associated with the expression of EZH2 in cervical cancer tissues. In conclusion, this study reveals that LINC01535 promotes cervical cancer progression via repressing the miR‐214/EZH2 regulatory loop.

MicroRNA‑206 exerts anti‑oncogenic functions in esophageal squamous cell carcinoma by suppressing the c‑Met/AKT/mTOR pathway

Increasing evidence suggests that the dysregulation of microRNAs (miRNAs) has an important role in the progression of human cancer, including ESCC. However, the exact functions and mechanisms of miRNAs in ESCC remain largely unclear. The aim of the present study was to investigate the expression and biological functions of miRNAs in ESCC and reveal the underlying molecular mechanisms. miRNA microarray and reverse transcription-quantitative polymerase chain reaction analyses were performed, which identified and confirmed that miR-206 was significantly downregulated in ESCC tissues and cell lines. Its low expression was associated with lymph node metastasis, advanced TNM stage and N classification, as well as poorer overall survival in patients with ESCC. CCK-8 and flow cytometry assays demonstrated that ectopic miR-206 expression inhibited ESCC cell proliferation and induced cell apoptosis. In addition, MET proto-oncogene, receptor tyrosine kinase (c-Met), a well-known oncogene, was a direct target of miR-206. An inverse correlation between the levels of miR-206 and c-Met mRNA in ESCC tissue samples was confirmed. Notably, c-Met overexpression inhibited the effects of miR-206 on the proliferation and apoptosis of ESCC cells. Additionally, it was confirmed that the tumor-suppressive functions of miR-206 may have contributed to the inactivation of the c-Met/protein kinase B (AKT)/mechanistic target of rapamycin (mTOR) signaling pathway. In conclusion, the findings of the present study suggested that miR-206 exerts its anti-cancer functions via the c-Met/AKT/mTOR signaling pathway, providing a novel candidate prognostic factor and a potential therapeutic target in ESCC.