MicroRNA‑497 inhibits cellular proliferation, migration and invasion of papillary thyroid cancer by directly targeting AKT3

Exosomal microRNA Therapy for Non-Small-Cell Lung Cancer

With the progress of molecular diagnosis research on non-small cell lung cancer (NSCLC) cells, four identified categories of microRNAs have been found to be related to disease diagnosis, diagnosis of treatment resistance, prediction of prognosis, and drugs for treatment. To date, nine target mRNA/signal pathways have been confirmed for microRNA drug therapy both in vitro and in vivo. When microRNA drugs enter blood vessels, they target the tumor site and play a similar role to that of targeted drugs. However, whether they will produce serious off-target effects remains unknown, and further clinical research is needed. This review provides the first summary of microRNA therapy for NSCLC.

MicroRNAs as the critical regulators of cell migration and invasion in thyroid cancer

Thyroid cancer (TC) is one of the most frequent endocrine malignancies that is more common among females. Tumor recurrence is one of the most important clinical manifestations in differentiated TC which is associated with different factors including age, tumor size, and histological features. Various molecular processes such as genetic or epigenetic modifications and non-coding RNAs are also involved in TC progression and metastasis. The epithelial-to-mesenchymal transition (EMT) is an important biological process during tumor invasion and migration that affects the initiation and transformation of early-stage tumors into invasive malignancies. A combination of transcription factors, growth factors, signaling pathways, and epigenetic regulations affect the thyroid cell migration and EMT process. MicroRNAs (miRNAs) are important molecular factors involved in tumor metastasis by regulation of EMT-activating signaling pathways. Various miRNAs are involved in the signaling pathways associated with TC metastasis which can be used as diagnostic and therapeutic biomarkers. Since, the miRNAs are sensitive, specific, and non-invasive, they can be suggested as efficient and optimal biomarkers of tumor invasion and metastasis. In the present review, we have summarized all of the miRNAs which have been significantly involved in thyroid tumor cells migration and invasion. We also categorized all of the reported miRNAs based on their cellular processes to clarify the molecular role of miRNAs during thyroid tumor cell migration and invasion. This review paves the way of introducing a non-invasive diagnostic and prognostic panel of miRNAs in aggressive and metastatic TC patients.

MicroRNAs in Papillary Thyroid Cancer: What Is New in Diagnosis and Treatment

Introduction

Papillary thyroid cancer (PTC) accounts for up to 80% of thyroid malignancies. New diagnostic and therapeutic options are suggested including innovative molecular methods. MicroRNAs (miRNAs) are nonprotein coding single-stranded RNAs that regulate many cell processes. The aim of the present study is to review the deregulated miRNAs associated with PTCs.

Methods

A bibliographic research was conducted, resulting in 272 articles referred to miRNAs and PTC. Regarding our exclusion criteria, 183 articles were finally included in our review.

Results

A remarkably large number of miRNAs have been found to be deregulated during PTC manifestation in the literature. The deregulated miRNAs are detected in tissue samples, serum/plasma, and FNA samples of patients with PTC. These miRNAs are related to several molecular pathways, involving genes and proteins responsible for important biological processes. MiRNA deregulation is associated with tumor aggressiveness, including larger tumor size, multifocality, extrathyroidal extension, lymphovascular invasion, lymph node and distant metastasis, and advanced tumor node metastasis stage.

Conclusion

MiRNAs are proposed as new diagnostic and therapeutic tools regarding PTC. They could be essential biomarkers for PTC diagnosis applied in serum and FNA samples, while their contribution to prognosis is of great importance.

Upregulation of circ_0000142 promotes multiple myeloma progression by adsorbing miR-610 and upregulating AKT3 expression

Circular RNAs (circRNAs) play an important regulatory role in a variety of malignancies. Nevertheless, the role of circ_0000142 in multiple myeloma (MM) and its regulatory mechanism remains largely unknown. Real-time polymerase chain reaction was employed to detect the expressions of circ_0000142 and miR-610 in MM tissues and cell lines. The expression of AKT3 and apoptosis-related proteins (Bcl-2, Bax) in MM cells was detected by western blot. The correlation between the expression level of circ_0000142 and the clinicopathological parameters of MM patients was analysed. Cell proliferation, apoptosis, migration and invasion were monitored by Cell Counting Kit 8 assay, flow cytometry analysis and Transwell assay, respectively. The dual-luciferase reporter gene assay and RNA immunoprecipitation assay were employed to verify the targeting relationship between circ_0000142 and miR-610. In this study, it was demonstrated that, circ_0000142 was highly expressed in MM patients, and its high expression level was significantly associated with increased International Staging System and Durie-Salmon stage. Overexpression of circ_0000142 enhanced MM cell proliferation, migration, invasion and suppressed cell apoptosis, while knocking down circ_0000142 had the opposite effects. Mechanistically, circ_0000142 functioned as a competitive endogenous RNA, directly targeting miR-610 and positively regulating AKT3 expression. In brief, circ_0000142 enhances the proliferation and metastasis of MM cells by modulating the miR-610/AKT3 axis.

Epigenetic signature associated with thyroid cancer progression and metastasis

Thyroid cancer is not among the top cancers in terms of diagnosis or mortality but it still ranks fifth among the cancers diagnosed in women. Infact, women are more likely to be diagnosed with thyroid cancer than the males. The burden of thyroid cancer has dramatically increased in last two decades in China and, in the United States, it is the most diagnosed cancer in young adults under the age of twenty-nine. All these factors make it worthwhile to fully understand the pathogenesis of thyroid cancer. Towards this end, microRNAs (miRNAs) have constantly emerged as the non-coding RNAs of interest in various thyroid cancer subtypes on which there have been numerous investigations over the last decade and half. This comprehensive review takes a look at the current knowledge on the topic with cataloging of miRNAs known so far, particularly related to their utility as epigenetic signatures of thyroid cancer progression and metastasis. Such information could be of immense use for the eventual development of miRNAs as therapeutic targets or even therapeutic agents for thyroid cancer therapy.

Hsa_circ_0000199 facilitates chemo-tolerance of triple-negative breast cancer by interfering with miR-206/613-led PI3K/Akt/mTOR signaling

Increasing attentions have been paid to the role of circRNAs in the etiology of triple-negative breast cancer (TNBC), and we strived to figure out the association of circRNA AKT3/miRNA axis with TNBC chemo-resistance. Altogether 207 BC patients were divided into TNBC group (n=83) and non-TNBC group (n=124), and MCF-10A, MDA-MB-231, MDA-MB-468, SK-BR-3 and MCF-7 cell lines were prepared in advance. Expressions of AKT3-derived circRNAs and relevant miRNAs in the TNBC tissues and cell lines were determined by employing real-time polymerase chain reaction (PCR). It was indicated that hsa_circ_0000199 expression was higher in TNBC tissues than in non-TNBC tissues, and high hsa_circ_0000199 expression was predictive of large tumor size, advanced TNM grade, high Ki-67 level and poor 3-year survival of TNBC patients (all P<0.05). Furthermore, miR-613 and miR-206 were sponged and negatively regulated by hsa_circ_0000199 (P<0.001), and PI3K/Akt/mTOR signaling was depressed by si-hsa_circ_0000199 in TNBC cell lines (P<0.01). Ultimately, miR-206/miR-613 inhibitor reversed impacts of si-hsa_circ_0000199 on PI3K/Akt/mTOR signaling, proliferation, migration, invasion, chemo-sensitivity and autophagy of TNBC cells (all P<0.01). Conclusively, silencing of hsa_circ_0000199 enhanced TNBC chemo-sensitivity by promoting miR-206/miR-613 expression and deactivating PI3K/Akt/mTOR signaling, which was conducive to improving chemotherapeutic efficacy of TNBC patients.

The DLG1-AS1/miR-497/YAP1 axis regulates papillary thyroid cancer progression

The long non-coding RNA (lncRNA), DLG1-AS1, is upregulated in papillary thyroid cancer (PTC) tissues and cell lines. Here, we found that increased expression of DLG1-AS1 caused lymph node metastasis and advanced tumor-node-metastasis (TNM) stage. DLG1-AS1 knockdown inhibited proliferation, invasion, and migration of PTC cells, and impaired tumorigenesis in vivo in mouse xenografts. DLG1-AS1 functions as a competing endogenous RNA (ceRNA) for miR-497. Further investigation revealed that DLG1-AS1 regulated yes-associated protein 1 (YAP1; a known target of miR-497) by competitively binding to miR-497. Moreover, inhibition of miR-497 abrogated the inhibitory effects of DLG1-AS1 depletion on PTC cells. These findings demonstrate that the DLG1-AS1-miR-497-YAP1 axis promotes the growth and metastasis of PTC by forming a ceRNA network.

Regulation of microRNA-497 expression in human cancer

MicroRNAs (miRNAs/miRs) are a type of non-coding single-stranded RNA, with a length of ~22 nt, which are encoded by endogenous genes and are involved in the post-transcriptional regulation of gene expression in animals and plants. Studies have demonstrated that miRNAs play an important role in the occurrence, development, metastasis, diagnosis and treatment of cancer. In recent years, miR-497 has been identified as one of the key miRNAs in a variety of cancer types and has been shown to be downregulated in a variety of solid tumors. However, the regulation of miR-497 expression involves a complex network, which is affected by several factors. The aim of the present review was to summarize the mechanism of regulation of miR-497 expression at the pre-transcriptional and transcriptional levels in cancer, as well as the role of miR-497 expression imbalance in cancer diagnosis, treatment and prognosis. The regulatory mechanisms of miR-497 expression may aid in our understanding of the causes of miR-497 expression imbalance and provide a reference value for further research on the diagnosis and treatment of cancer.

Circ_0000144 facilitates the progression of thyroid cancer via the miR-217/AKT3 pathway

BACKGROUND

Thyroid carcinoma (TC) is the most common malignancy of the endocrine system. Circular RNA (circRNA) is vital in the regulation of tumor progression. Circ_0000144 serves as a novel oncogenic circRNA, and miR-217 is reported to inhibit the malignant phenotypes of cancer cells by targeting AKT3 in TC. The present study aimed to explore the regulatory mechanism of circ_0000144 and miR-217 in the progression of TC.

METHODS

Circ_0000144 expression in 32 pairs of TC tissues and different TC cell lines (including BCPAP, K1, H7H83, and TPC-1) was detected by employing a quantitative real-time polymerase chain reaction (qRT-PCR). Circ_0000144 small interfering RNA was used to establish loss-of-function models. Cell counting kit-8 (CCK-8), BrdU (5-bromo-2'-deoxyuridine) and transwell assays were utilized to verify the effects of circ_0000144 on TC cell proliferation, migration and invasion, respectively. Bioinformatics, western blotting, a luciferase reporter experiment and qRT-PCR were employed to confirm the relationships among circ_0000144, miR-217 and AKT3.

RESULTS

Circ_0000144 expression was remarkably elevated in TC tissues (p < 0.001) and TC cell lines. The elevation of circ_0000144 expression was markedly linked to tumor size (p = 0.015), TNM stage (p = 0.025) and lymph node metastasis (p = 0.017) of the patients. Functional studies showed that knocking down circ_0000144 repressed the malignancy of TC cells. Furthermore, miR-217 was identified as a downstream target of circ_0000144; inhibition of miR-217 could reverse the effects induced by circ_0000144 knockdown. Moreover, circ_0000144 could regulate AKT3 expression by suppressing miR-217 expression.

CONCLUSIONS

Circ_0000144 exerts a cancer-promoting effect on TC cells via the miR-217/AKT3 pathway.

MicroRNA-203 restrains epithelial-mesenchymal transition, invasion and migration of papillary thyroid cancer by downregulating AKT3

MicroRNAs (miRNAs) have been reported to serve pivotal roles in the regulation of papillary thyroid cancer (PTC) development; thus, the aim of this study is to identify the impact of miR-203 and AKT3 on the epithelial-mesenchymal transition (EMT), migration and invasion of PTC. MiR-203 and AKT3 expression in PTC tissues and cells were tested. TPC-1 cells and K1 cells were screened for follow-up experiments. Apoptosis-related proteins (Bcl-2 and Bax), EMT-related proteins (Vimentin and E-cadherin), proliferation-associated proteins (Ki67 and CDK4), invasion- and migration-related protein (MMP-2 and MMP-9) were verified. The effects of upregulated miR-203 and downregulated AKT3 on the biological characteristics of PTC cells in each group were detected via the gain- and loss-of-function assays. The targeting relationship between miR-203 and AKT3 was verified.MiR-203 expression declined and AKT3 heightened in PTC tissues and cells. Upregulated miR-203 and downregulated AKT3 reduced the tumor volume and weight, suppressed cell migration, colony formation, proliferation, invasion, proliferation-associated proteins (Ki67 and CDK4), invasion- and migration-related protein (MMP-2 and MMP-9) and promoted cell apoptosis, raised E-cadherin and decreased Vimentin protein expression in TPC-1 cells. On the contrary, the K1 cells with the downregulated miR-203 or upregulated AKT3 exhibited an opposite result. This study suggests that upregulated miR-203 suppresses EMT, invasion, proliferation and migration as well as induces apoptosis of PTC cells via downregulated AKT3.

Exosome-mediated microRNA-497 delivery for anti-cancer therapy in a microfluidic 3D lung cancer model

Non-small cell lung cancer (NSCLC) is one of the leading causes of death from cancer worldwide. The delivery and controlled regulation of miRNAs via exosomes is known as a potential therapeutic approach in the treatment of cancer. In this study, human cell-derived exosomes were used as delivery vehicles for miRNAs, and we investigated their anti-tumor and anti-angiogenic effects on NSCLCs that were cultured in 2D and 3D microfluidic devices. We demonstrated that exosomes that contained miRNA-497 (miR-497) effectively suppressed tumor growth and the expression of their associated genes, i.e., yes-associated protein 1 (YAP1), hepatoma-derived growth factor (HDGF), cyclin E1 (CCNE1), and vascular endothelial growth factor-A (VEGF-A), in A549 cells. Also, the level of VEGF-A-mediated angiogenic sprouting was decreased drastically in human umbilical vein endothelial cells (HUVECs) cultured in a microfluidic device. To mimic the in vivo-like tumor microenvironment of NSCLC, A549 cells were co-cultured with HUVECs in a single device, and miR-497-loaded exosomes were delivered to both types of cells. As a result, both the tube formation of endothelial cells and the migration of tumor decreased dramatically compared to the control. This indicated that miR-497 has synergistic inhibitory effects that target tumor growth and angiogenesis, so exosome-mediated miRNA therapeutics combined with the microfluidic technology could be a predictive, cost-efficient translational tool for the development of targeted cancer therapy.

Prognostic values and prospective pathway signaling of MicroRNA-182 in ovarian cancer: a study based on gene expression omnibus (GEO) and bioinformatics analysis

BACKGROUND

Ovarian carcinoma (OC) is a common cause of death among women with gynecological cancer. MicroRNAs (miRNAs) are believed to have vital roles in tumorigenesis of OC. Although miRNAs are broadly recognized in OC, the role of has-miR-182-5p (miR-182) in OC is still not fully elucidated.

METHODS

We evaluated the significance of miR-182 expression in OC by using analysis of a public dataset from the Gene Expression Omnibus (GEO) database and a literature review. Furthermore, we downloaded three mRNA datasets of OC and normal ovarian tissues (NOTs), GSE14407, GSE18520 and GSE36668, from GEO to identify differentially expressed genes (DEGs). Then the targeted genes of hsa-miR-182-5p (TG_miRNA-182-5p) were predicted using miRWALK3.0. Subsequently, we analyzed the gene overlaps integrated between DEGs in OC and predicted target genes of miR-182 by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. STRING and Cytoscape were used to construct a protein-protein interaction (PPI) network and the prognostic effects of the hub genes were analyzed.

RESULTS

A common pattern of up-regulation for miR-182 in OC was found in our review of the literature. A total of 268 DEGs, both OC-related and miR-182-related, were identified, of which 133 genes were discovered from the PPI network. A number of DEGs were enriched in extracellular matrix organization, pathways in cancer, focal adhesion, and ECM-receptor interaction. Two hub genes, MCM3 and GINS2, were significantly associated with worse overall survival of patients with OC. Furthermore, we identified covert miR-182-related genes that might participate in OC by network analysis, such as DCN, AKT3, and TIMP2. The expressions of these genes were all down-regulated and negatively correlated with miR-182 in OC.

CONCLUSIONS

Our study suggests that miR-182 is essential for the biological progression of OC.

MiR-16-5p inhibits breast cancer by reducing AKT3 to restrain NF-κB pathway

Background: Breast cancer endangers the life of women and has become the major cause of deaths among them. MiRNAs are found to exert a regulatory effect on the migration, proliferation and apoptosis of breast cancer cells. This research aims at investigating the miR-16-5p expression and its effect on the pathogenesis of breast cancer. Methods: Their clinical data were analyzed with qRT-PCR. CCK8, EdU and Transwell was performed to explore the function of miR-16-5p in cell migration and proliferation of breast cancer cells. Dual-luciferase reporter assay, immunohistochemistry and Western blotting were carried out to explore the relation between miR-16-5p and AKT3. Results: It was discovered that miR-16-5p was lowly expressed in breast cancer patients. Meanwhile, breast cancer patients with under-expressed miR-16-5p had a lower survival rate than those with highly expressed miR-16-5p. Furthermore, decreased miR-16-5p in cell and animal models enhanced migration and proliferation of breast cancer cells, stimulated cell cycle and reduced cell apoptosis. Finally, we found miR-16-5p restrained the NF-κB pathway and decreased AKT3 gene, thereby suppressing the breast cancer development. Conclusion: It can be seen that miR-16-5p exhibits a low expression in breast cancer tissues, which can inhibit breast cancer by restraining the NF-κB pathway and elevating reducing AKT3.

Down-regulated HSDL2 expression suppresses cell proliferation and promotes apoptosis in papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer. Hydroxysteroid dehydrogenase like 2 (HSDL2) can regulate lipid metabolism and take part in cell proliferation. The purpose of the present study was to explore functional role of HSDL2 gene in PTC. The expression of HSDL2 protein in PTC tissues was estimated using immunohistochemistry analysis (IHC). HSDL2 mRNA level was detected through quantitative real-time polymerase chain reaction (qRT-PCR). Effects of HSDL2 gene on cell proliferation and apoptosis were assessed using the shRNA method for both in vitro and in vivo experiments. Potential target genes of HSDL2 were determined via bioinformatics analyses and Western blotting. HSDL2 was up-regulated in PTC tissues and cell lines compared with the controls (all P<0.05). Inhibiting HSDL expression could suppress PTC cell proliferation and cycle, and promote apoptosis in vitro. In vivo, the knockdown of HSDL2 gene could significantly suppress tumor growth (all P<0.05). Furthermore, AKT3, NFATc2 and PPP3CA genes might be potential targets of HSDL2 in PTC. HSDL2 expression was increased in PTC tissues and cells, which could promote tumor progression in vitro and in vivo.

Genetic polymorphisms of miRNA let7a-2 and pri-mir-34b/c are associated with an increased risk of papillary thyroid carcinoma and clinical/pathological features

microRNAs (miRNAs) as a group of short noncoding RNAs are crucial molecules in transcriptional and translational regulation of oncogenes and tumor suppressor genes. Evidence showed there was an association between the miRNA polymorphisms and various cancers, including papillary thyroid carcinoma (PTC). The present study aims to evaluate the possible effects of let7a-2 rs1143770 and pri-mir-34b/c rs4938723 polymorphisms on PTC susceptibility. A total of 120 patients with PTC and 130 age, sex, and race matched controls were enrolled in the case-control study. The polymerase chain reaction-restriction fragment length polymorphism method was used for genotyping of let7a-2 rs1143770 and pri-mir-34b/c rs4938723 polymorphisms. The let7a-2 rs1143770 CT and TT genotypes were associated with a 1.9-fold and 2.2-fold higher risk of PTC, respectively (P = 0.027 and P = 0.041). Moreover, the let7a-2 rs1143770 polymorphism was associated with increased PTC risk in both dominant (2-fold, P = 0.015) and the allelic model (1.5-fold, P = 0.03). The frequency of pri-mir-34b/c rs4938723TC genotype was significantly higher in patients with PTC and associated with a two-fold higher risk of PTC (P = 0.013). In addition, this polymorphism was associated with a 1.8-fold increased risk of PTC in dominant model (P = 0.021). The let7a-2 rs1143770CT genotype was associated with a 3.5-fold increased risk of N1 stage in PTC patients (P = 0.04), however, pri-mir-34b/c rs4938723TC genotype was associated with a 3.4-fold and 5.1-fold increased risk of III-IV stage and vascular invasion in PTC group, respectively (P = 0.04 and P = 0.04). In conclusion, the present study shows that let7a-2 rs1143770 and pri-mir-34b/c rs4938723 polymorphisms could be susceptible factors for PTC and some clinical features.

Regulatory effect of miR-195 in the placental dysfunction of preeclampsia

Purpose: Preeclampsia (PE) is a pregnancy specific disease soon after 20 weeks of gestation where major symptoms are hypertension and proteinuria. The underlying pathology is believed to be abnormal placentation. Epigenetic and genetic factors have significant roles in abnormal placental development. MicroRNA's (miRNAs), being one of the most important epigenetic regulators, take part in abnormal placentation. Hsa-miR-195 is a molecule associated with abnormal placental growth mechanisms such as impaired cellular proliferation, inadequate trophoblastic invasion causing defective spiral artery remodeling, and apoptosis. We aimed to evaluate miRNA functions, namely miR-195 expression profile, in order to divulge PE pathogenesis.Methods: In this study, we extracted circulating miRNAs from maternal plasma and placenta from 20 PE patients and 20 normotensive pregnant women. miR-195 was quantified using quantitative real time reverse transcriptase PCR (qRT-PCR). The target genes of miR-195 were predicted by Diana Tools-mirPath, TargetScan, and miRDB databases.Results: We found that miR-195 levels were downregulated (3.83-fold decrease, p < .05) in preeclamptic placenta samples, however miR-195 were undetected in preeclamptic and normotensive plasma samples. The steep down-regulation of miR-195 points to its importance of PE pathogenesis.Conclusion: miR-195 is suggested to regulate PE via its target genes manipulating biological processes such as placental proliferation, apoptosis, and angiogenesis. We propose that detection of decreased miR-195 levels in preeclamptic placentas could be used to enlighten the pathophysiology of PE.

Downregulation of miR‑486‑5p in papillary thyroid carcinoma tissue: A study based on microarray and miRNA sequencing

Abnormal expression of microRNA (miR) is associated with the occurrence and progression of various types of cancers, including papillary thyroid carcinoma (PTC). In the present study, the aim was to explore miR‑486‑5p expression and its role in PTC, as well as to investigate the biological function of its potential target genes. The expression levels of miR‑486‑5p and its clinicopathological significance were examined in 507 PTC and 59 normal thyroid samples via The Cancer Genome Atlas (TCGA). Subsequently, the results were validated using data from Gene Expression Omnibus (GEO) and ArrayExpress. Receiver operating characteristic and summary receiver operating characteristic curves were used to assess the ability of miR‑486‑5p in distinguishing PTC from normal tissue. Furthermore, potential miR‑486‑5p mRNA targets were identified using 12 prediction tools and enrichment analysis was performed on the encoding genes using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes. The expression levels of miR‑486‑5p were consistently downregulated in PTC compared with in normal tissue across datasets from TCGA, GEO (GSE40807, GSE62054 and GSE73182) and ArrayExpress (E‑MTAB‑736). The results also demonstrated that miR‑486‑5p expression was associated with cancer stage (P=0.003), pathologic lymph node (P=0.047), metastasis (P=0.042), neoplasm (P=0.012) and recurrence (P=0.016) in patients with PTC. In addition, low expression of miR‑486‑5p in patients with PTC was associated with a worse overall survival. A total of 80 miR‑486‑5p‑related genes were observed from at least 9 of 12 prediction platforms, and these were involved in 'hsa05200: Pathways in cancer' and 'hsa05206: MicroRNAs in cancer'. Finally, three hub genes, CRK like proto‑oncogene, phosphatase and tensin homolog and tropomyosin 3, were identified as important candidates in tumorigenesis and progression of PTC. In conclusion, it may be hypothesized that miR‑486‑5p contributes towards PTC onset and progression, and may act as a clinical target. However, in vitro and in vivo experiments are required to validate the findings of the present study.

MicroRNA-16 functions as a tumor-suppressor gene in oral squamous cell carcinoma by targeting AKT3 and BCL2L2

Aberrant expressions of microRNAs have been reported to be strongly associated with the progression and prognosis of various tumors, including oral squamous cell carcinoma (OSCC). Recent studies on miRNA expression profiling have suggested that microRNA-16 (miR-16) may be dysregulated in OSCC. However, the tumorigenic roles and mechanisms of miR-16 in OSCC are still largely unknown. In this study, we demonstrated that miR-16 was specifically downregulated in both OSCC patients and cancer cell lines. In addition, functional roles of miR-16 in vitro suggested that the miR-16 mimic inhibited cell proliferation and induced apoptosis, whereas miR-16 inhibitor displayed the opposite effects. Luciferase reporter assay and correlation analysis showed that AKT3 and BCL2L2 were directly targeted by miR-16 and were inversely expressed with miR-16 in OSCC. Moreover, restoration of AKT3 and BCL2L2 expression could partially reverse the cell proliferation inhibition and apoptosis induction caused by miR-16. In xenograft nude mice, miR-16 mimics decreased the expression of AKT3 and BCL2L2 and reduced the tumors volumes and weights, whereas the miR-16 inhibitor exhibited adverse effects in the derived xenografts. In conclusion, the findings suggested that miR-16 functions as a tumor suppressor miRNA to inhibit cell proliferation and induce apoptosis in OSCC through decreasing the oncogenes AKT3 and BCL2L2 and that miR-16 could be a potential therapeutic target for OSCC.