miR-139-5p suppresses cancer cell migration and invasion through targeting ZEB1 and ZEB2 in GBM

Downregulation of miR-130a promotes cell growth and epithelial to mesenchymal transition by activating HMGB2 in glioma

Aberrant expression of miR-130a is usually found in cancer studies; however, the role of miR-130a has seldom been reported in glioma. We explored miR-130a's function and the underlying mechanism in glioma. It was found that miR-130a expression was significantly down-regulated in glioma tissues and cell lines. Overexpression of miR-130a decreased glioma cell growth and invasion both in vitro and in vivo. We identified the oncogene HMGB2 as a downstream target of miR-130a by using luciferase and western blot assays. Knockdown of HMGB2 mimicked the effect of miR-130a in glioma cells. Taken together, our study demonstrate that miR-130a may function as a tumor suppressor in glioma and suggest that miR-130a is a potential therapeutic target for glioma patients.

MiR-139-5p inhibits the tumorigenesis and progression of oral squamous carcinoma cells by targeting HOXA9

Our study sought to clarify the effects of microRNA-139-5p (miR-139-5p) in the tumorigenesis and progression of oral squamous cell carcinoma (OSCC) by regulating HOXA9. MiR-139-5p and HOXA9 expression in OSCC tissues, tumour adjacent tissues, OSCC cells and normal cells were tested by qRT-PCR. SAS and CAL-27 cell lines were selected in among four OSCC cell lines and then transfected with miR-139-5p mimics, pEGFP-HOXA9 and cotransfected with miR-139-5p mimics + pEGFP-HOXA9. We used MTT, colony formation, transwell and wound healing assays to analyse cell viability, proliferation, invasion and migration. The target relationship between miR-139-5p and HOXA9 was verified by luciferase reporter assay and Western blot, respectively. MiR-139-5p was down-regulated, whereas HOXA9 was up-regulated in OSCC tissues and cells. The proliferation, invasion and migration ability of SAS and CAL-27 cells in miR-139-5p mimics group were significantly weaker than those in the control group and the miR-NC group (P < 0.01). MiR-139-5p can negatively regulate HOXA9. The proliferation, invasion and migration of SAS and CAL-27 cells in the miR-139-5p mimics + pEGFP-HOXA9 group were not significantly different from those in the blank control and negative control groups (P > 0.05). Our results indicated that miR-139-5p could directly inhibit HOXA9, which might be a potential mechanism in inhibiting the proliferation, invasiveness and migration of OSCC cells.

miRNA Regulation in Gliomas: Usual Suspects in Glial Tumorigenesis and Evolving Clinical Applications

In recent years, an increasing role for noncoding small RNAs (miRNA) has been uncovered in carcinogenesis. These oligonucleotides can promote degradation and/or inhibit translation of key mRNAs. Recent studies have also highlighted a possible role for miRNAs in adult and pediatric brain tumors, including high- and low-grade gliomas, medulloblastoma, ependymoma, and neoplasms associated with neurofibromatosis type 1. Gliomas represent the most common category of primary intraparenchymal brain tumors, and, for example, manipulation of signaling pathways, through inhibition of PTEN transcription appears to be an important function of miRNA dysregulation through miR-21, miR-106b, and miR-26a. Moreover, altered miRNA expression in gliomas play roles in the regulation of common tumorigenic processes, including receptor tyrosine kinase signaling, angiogenesis, invasion, suppression of differentiation, cell cycle enhancement, and inhibition of apoptosis. Suppression of differentiation requires the downregulation of a number of miRNAs that are both enriched in the brain and required for terminal glial differentiation, including miR-219 and miR-338. Our evolving understanding about the biology of gliomas make them attractive for miRNA study, given that recent evidence suggests that epigenetic and subtle genetic changes may contribute to their pathogenesis. Identification of key miRNAs also provides a rationale for developing robust biomarkers and inhibitory RNA strategies for therapeutic purposes in glioma patients.

MicroRNA‑139 suppressed tumor cell proliferation, migration and invasion by directly targeting HDGF in epithelial ovarian cancer

The current study investigated the expression and functional roles of microRNA‑139 (miR‑139) on human epithelial ovarian cancer (EOC). Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was performed to measure miR‑139 expression in EOC tissues and cell lines. The effects of miR‑139 on EOC cell proliferation, migration and invasion were assessed using MTT, cell migration and invasion assays, respectively. Subsequently, the molecular mechanism underlying the tumor suppressive roles of miR‑139 on EOC was determined by bioinformatics analysis, RT‑qPCR, western blotting and the luciferase reporter assay. According to the results, it was identified that miR‑139 was significantly downregulated in EOC tissues and cell lines. In addition, restoration of miR‑139 suppressed tumor cell proliferation, migration and invasion in EOC. Furthermore, hepatoma‑derived growth factor (HDGF) was identified as a target of miR‑139 in EOC. Upregulation of HDGF could rescue the inhibitory effects exerted by miR‑139 overexpression on EOC cell proliferation, migration and invasion. Collectively, the results indicated that miR‑139 was downregulated in EOC, and acted as a tumor suppressor by directly targeting HDGF. To the best of our knowledge, this was the first study to identify that miR‑139 contributes to the growth and metastasis of EOC.

MiR-139-5p as a novel serum biomarker for recurrence and metastasis in colorectal cancer

Approximately 30-50% of colorectal cancer (CRC) patients who undergo curative resection subsequently experience tumor recurrence or metastasis. Although microRNAs (miRNAs) are a class of small noncoding RNAs frequently deregulated in various human malignancies, it remains unknown if these can help predict recurrence and metastasis in CRC patients. MiRNAs were initially screened using miRNA-microarray and miRNA-seq datasets with or without recurrence. Candidate miRNAs were then tested in two independent cohorts of 111 stage II/III and 139 stage I-III CRC patients, as well as serum samples and matched primary and metastatic liver tissues. An animal model of peritoneal dissemination was used to assess the oncogenic role of the target miRNA. Four candidate miRNAs were identified during the initial screening, and we subsequently validated upregulation of miR-139-5p in two independent clinical cohorts, wherein it associated with poor recurrence-free survival. Moreover, miR-139-5p were also upregulated in the serum of recurrence-positive CRC patients and yielded significantly shorter recurrence-free survival. Intriguingly, miR-139-5p was upregulated in metastatic liver tissues and negatively correlated with genes associated with epithelial-mesenchymal transition. Lastly, we showed that miR-139-5p overexpression enhanced peritoneal dissemination in a mouse model. In conclusion, we identified miR-139-5p as a novel biomarker for tumor recurrence and metastasis in CRC.

Role of miRNAs in human cancer metastasis: Implications for therapeutic intervention

Metastasis is the spread and growth of localized cancer to new locations in the body and is considered the main cause of cancer-related deaths. Metastatic cancer cells display distinct genomic and epigenomic profiles and almost universally an aggressive pathophysiology. A better understanding of the molecular mechanisms and regulation of metastasis, including how metastatic tumors grow and survive in the nascent niche and the interactions of the emergent metastatic cancer cells within the local microenvironment may provide tools to design strategies to restrict metastatic dissemination. Aberrant microRNAs (miRNA) expression has been reported in metastatic cancer cells. MicroRNAs are known to regulate divergent and/or convergent metastatic gene pathways including activation of reprogramming switches during metastasis. An in-depth understanding of role of miRNAs in the metastatic cascade may lead to the identification of novel targets for anti-metastatic therapeutics as well as potential candidate miRNAs for cancer treatment. This review primarily focuses on the role of miRNAs in the mechanisms of cancer metastasis as well as implications for metastatic cancer treatment.

Role of miR-139 as a surrogate marker for tumor aggression in breast cancer

MicroRNAs are non-protein coding molecules that play a key role in oncogenesis, tumor progression, and metastasis in many types of malignancies including breast cancer. In the current study, we studied the expression of microRNA-139-5p (miR-139) in invasive ductal carcinoma (IDC) of the breast and correlated its expression with tumor grade, molecular subtype, hormonal status, human epidermal growth factor receptor 2 status, proliferation index, tumor size, lymph node status, patient's age, and overall survival in 74 IDC cases. In addition, we compared and correlated miR-139 expression in 18 paired serum and tissue samples from patients with IDC to assess its value as a serum marker. Our data showed that miR-139 was down-regulated in all tumor tissue samples compared with control. More pronounced down-regulation was seen in tumors that were higher grade, estrogen receptor negative, progesterone receptor negative, more proliferative, or larger in size (P < .05). Although not statistically significant, lower miR-139 level was frequently associated with human epidermal growth factor receptor 2 overexpression. In addition, significantly lower miR-139 tissue level was seen in patients who were deceased (P = .027), although older age (>50 years) and positive local nodal disease did not adversely affect miR-139 expression. In contrast, serum miR-139 profile of the patients appeared similar to that of normal control. In conclusion, our study demonstrated that down-regulation of miR-139 was associated with aggressive tumor behavior and disease progression in breast cancer. miR-139 may serve as a risk assessment biomarker in tailoring treatment options.

MicroRNA-106a-5p facilitates human glioblastoma cell proliferation and invasion by targeting adenomatosis polyposis coli protein

The invasive behavior of glioblastoma multiforme (GBM) cells is an important reason for its poor prognosis. Tumor cells acquire an ability to digest the extracellular matrix and infiltrate the adjacent normal tissue during invasion. Restraining GBM invasion by changing effector molecules can significantly improve the patient's prognosis. MiRNAs are involved in multiple biological functions via suppressing target genes. In this study, we found that miR-106a-5p expression was high in GBM tissues and cells. The data showed an inverse correlation in GBM tissues between the levels of miR-106a-5p and adenomatosis polyposis coli (APC) mRNAs.Additionally, ectopic expression of miR-106a-5pfacilitated the invasion of GBM cells whereas inhibition of miR-106a-5p expression weakened the invasive ability. Numerous transcription factors are downstream effectors of the Wnt/β-catenin pathway. Target prediction databases and luciferase data showed that APC is a new direct target of miR-106a-5p. Importantly, westernblot assays demonstrated that miR-106a-5p can reduce APC protein level and enhance target proteins of Wnt/β-catenin pathway. Thus, we hypothesize that miR-106a-5p directly targets APC, resulting in the activation of Wnt/β-catenin pathway. Our results suggest that miR-106a-5p is involved in the invasive behavior of GBM cells and by targeting APC and activating Wnt/β-catenin pathway, it provides a theoretical basis for developing potential clinical strategies.

Role of HCP5-miR-139-RUNX1 Feedback Loop in Regulating Malignant Behavior of Glioma Cells

Aberrant expression of long noncoding RNAs has recently been reported in tumorigenesis and plays a pivotal role in regulating malignant behavior of cancers. In this study, we confirmed that the long noncoding RNAs human histocompatibility leukocyte antigen (HLA) complex P5 (HCP5) was up-regulated in glioma tissues as well as in U87 and U251 cells. Knockdown of HCP5 inhibited the malignant biological behavior of glioma cells by reducing proliferation, migration and invasion, and inducing apoptosis. HCP5 regulated the malignant behavior of glioma cells by binding to microRNA-139, which functions as a tumor suppressor. Moreover, knockdown of HCP5 down-regulated Runt-related transcription factor 1, a direct and functional downstream target of microRNA-139 that is involved in microRNA-139-mediated tumor-suppressive effects in glioma cells. Runt-related transcription factor 1 increased promoter activities and upregulated expression of the oncogenic gene astrocyte elevated gene-1 (AEG-1). Runt-related transcription factor 1 also increased the promoter activities and expression of HCP5, which showed a positive feedback loop in regulating the malignant behavior of glioma cells. In conclusion, this study demonstrated that the HCP5-microRNA-139- Runt-related transcription factor 1 feedback loop plays a pivotal role in regulating the malignant behavior of glioma cells, which may provide a potential therapeutic strategy for treating glioma.

miR-139 Functions as An Antioncomir to Repress Glioma Progression Through Targeting IGF-1 R, AMY-1, and PGC-1β

Gliomas are the most common primary malignant brain tumor with poor prognosis, characterized by a highly heterogeneous cell population, extensive proliferation, and migration. A lot of molecular mechanisms regulate gliomas development and invasion, including abnormal expression of oncogenes and variation of epigenetic modification. MicroRNAs could affect cell growth and functions. Several reports have demonstrated that miR-139 plays multifunctions in kinds of solid tumors through different pathways. However, the antitumor mechanisms of this miR-139 are not unveiled in detail. In this study, we not only validated the low expression level of miR-139 in glioma tissues and cell lines but also detected the effect of miR-139 on modulating gliomas proliferation and invasion both in vitro and in vivo. We identified insulin-like growth factor 1 receptor, associate of Myc 1, and peroxisome proliferator-activated receptor γ coactivator 1β as direct targets of miR-139 and the levels of them were all inversely correlated with miR-139 in gliomas. Insulin like growth factor 1 receptor promoted gliomas invasion through Akt signaling and increased proliferation in the peroxisome proliferator-activated receptor γ coactivator 1β-dependent way. Associate of Myc 1 also facilitated gliomas progression by activating c-Myc pathway. Overexpression of the target genes could retrieve the antitumor function of miR-139, respectively, in different degrees. The nude mice transplantation tumor experiment displayed that glioma cells stably expressed miR-139 growth much slower in vivo than the negative control cells. Taken together, these findings suggested miR-139 acted as a favorable factor against gliomas progression and uncovered a novel regulatory mechanism, which may provide a new evidenced prognostic marker and therapeutic target for gliomas.

miR-590-3p suppresses cancer cell migration, invasion and epithelial-mesenchymal transition in glioblastoma multiforme by targeting ZEB1 and ZEB2

Invasion and migration of glioblastoma multiforme (GBM) is a multistep process and an important phenotype that causes this disease to invade surrounding tissues in the brain. The purpose of this study was to determine the role of miR-590-3p in regulation of epithelial mesenchymal transition (EMT) and metastasis of GBM cells. Expression levels of miR-590-3p in 15 GBM specimens with adjacent tissues and five GBM cell lines were assessed by quantitative RT-PCR. We found that miR-590-3p was down-regulated in detected GBM tissue samples and all of the GBM cell lines. In addition, Ectopic expression of miR-590-3p suppressed and miR-590-3p-in promoted EMT, migration, and invasion in U87MG and A172 cells. Bioinformatics coupled with luciferase and Western blot assays also revealed that miR-590-3p inhibited expression of ZEB1 and ZEB2, which are master regulators of tumor metastasis. Our study first indicates that miR-590-3p functions as a suppressor of GBM EMT and metastasis by targeting ZEB1 and ZEB2, and it may be a therapeutic target for metastatic GBM.