miR-154 suppresses colorectal cancer cell growth and motility by targeting TLR2

Machine learning and experimental analyses identified miRNA expression models associated with metastatic osteosarcoma

Osteosarcoma (OS), as the most common primary bone cancer, has a high invasiveness and metastatic potential, therefore, it has a poor prognosis. This study identified early diagnostic biomarkers using miRNA expression profiles associated with osteosarcoma metastasis. In the first step, we used RNA-seq and online microarray data from osteosarcoma tissues and cell lines to identify differentially expressed miRNAs. Then, using seven feature selection algorithms for ranking, the first-ranked miRNAs were selected as input for five machine learning systems. Using network analysis and machine learning algorithms, we developed new diagnostic models that successfully differentiated metastatic osteosarcoma from non-metastatic samples based on newly discovered miRNA signatures. The results showed that miR-34c-3p and miR-154-3p act as the most promising models in the diagnosis of metastatic osteosarcoma. Validation for this model by RT-qPCR in benign tissue and osteosarcoma biopsies confirmed the lower expression of miR-34c-3p and miR-154-3p in OS samples. In addition, a direct correlation between miR-34c-3p expression, miR-154-3p expression and tumor grade was discovered. The combined values of miR-34c-3p and miR-154-3p showed 90 % diagnostic power (AUC = 0.90) for osteosarcoma samples and 85 % (AUC = 0.85) for metastatic osteosarcoma. Adhesion junction and focal adhesion pathways, as well as epithelial-to-mesenchymal transition (EMT) GO terms, were identified as the most significant KEGG and GO terms for the top miRNAs. The findings of this study highlight the potential use of novel miRNA expression signatures for early detection of metastatic osteosarcoma. These findings may help in determining therapeutic approaches with a quantitative and faster method of metastasis detection and also be used in the development of targeted molecular therapy for this aggressive cancer. Further research is needed to confirm the clinical utility of miR-34c-3p and miR-154-3p as diagnostic biomarkers for metastatic osteosarcoma.

miR-154-5p Is a Novel Endogenous Ligand for TLR7 Inducing Microglial Activation and Neuronal Injury

Toll-like receptors (TLRs) are a collection of pattern recognition sensors that form a first line of defence by detecting pathogen- or damage-associated molecular patterns and initiating an inflammatory response. TLR activation in microglia, the major immune cells in the brain, can trigger the release of inflammatory molecules, which may contribute to various CNS diseases including Alzheimer's disease. Recently, some microRNAs were shown to serve as signalling molecules for TLRs. Here, we present miR-154-5p as a novel TLR7 ligand. Exposing microglia to miR-154-5p results in cytokine release and alters expression of the TLR signalling pathway dependent on TLR7. Additionally, miR-154-5p causes neuronal injury in enriched cortical neuron cultures and additive toxicity in the presence of microglia. Finally, intrathecal injection of miR-154-5p into mice leads to neuronal injury and accumulation of microglia in the cerebral cortex dependent on TLR7 expression. In conclusion, this study establishes miR-154-5p as a direct activator of TLR7 that can cause neuroinflammation and neuronal injury, which may contribute to CNS disease.

miR-152/TNS1 axis inhibits non-small cell lung cancer progression through Akt/mTOR/RhoA pathway

AIM

The purpose of the present study was to explore the function and mechanism of tensin 1 (TNS1) in non-small cell lung cancer (NSCLC) progression.

METHODS

The expression of TNS1 in NSCLC cells and tissues was assessed by RT-PCR and Western blot. Besides, Kaplan-Meier survival analysis was recruited to explore the association between TNS1 and NSCLC. Cell growth was analyzed by MTT and flow cytometry assay, while cell metastasis was determined by wound healing and transwell assays. The targeting relationship between TNS1 and miR-152 was assessed by luciferase activity assays. And Western blot was employed to determine the expression of related proteins of Akt/mTOR/RhoA pathway.

RESULTS

TNS1 level was boosted in NSCLC cells and tissues, related to the prognosis of NSCLC patients. Furthermore, it was proved that TNS1 promoted the growth and metastasis of NSCLC cells via Akt/mTOR/RhoA pathway. And miR-152 targeted TNS1 to affect the progression of NSCLC.

CONCLUSION

miR-152/TNS1 axis inhibits the progression of NSCLC by Akt/mTOR/RhoA pathway.

MicroRNA-154: A Novel Candidate for Diagnosis and Therapy of Human Cancers

MicroRNAs (miRNAs) are endogenous, non-coding, single-stranded, tiny RNAs with 21–23 nucleotides that regulate several biological functions through binding to target mRNAs and modulating gene expression at post-transcriptional levels. Recent studies have described crucial roles for miRNAs in pathophysiology of numerous human cancers. They can act as an oncogene and promote cancer or as a tumor suppressor and alleviate the disease. Recently discovered microRNA-154 (miR-154) has been proposed to be involved in multiple physiological and pathological processes including cancer. With this aspect, aberrant expression of miR-154 has been demonstrated in variety of human malignancies, suggesting an important role for miR-154 in tumorigenesis. To be specific, it is considered as a tumor suppressor miRNA and exerts its beneficial effects by targeting several genes. This review systematically summarizes the recent advances done on the role of miR-154 in different cancers and discusses its potential prognostic, diagnostic and therapeutic values.

Toll-like Receptors from the Perspective of Cancer Treatment

Toll-like receptors (TLRs) represent a family of pattern recognition receptors that recognize certain pathogen-associated molecular patterns and damage-associated molecular patterns. TLRs are highly interesting to researchers including immunologists because of the involvement in various diseases including cancers, allergies, autoimmunity, infections, and inflammation. After ligand engagement, TLRs trigger multiple signaling pathways involving nuclear factor-κB (NF-κB), interferon-regulatory factors (IRFs), and mitogen-activated protein kinases (MAPKs) for the production of various cytokines that play an important role in diseases like cancer. TLR activation in immune as well as cancer cells may prevent the formation and growth of a tumor. Nonetheless, under certain conditions, either hyperactivation or hypoactivation of TLRs supports the survival and metastasis of a tumor. Therefore, the design of TLR-targeting agonists as well as antagonists is a promising immunotherapeutic approach to cancer. In this review, we mainly describe TLRs, their involvement in cancer, and their promising properties for anticancer drug discovery.

LncRNA MALAT1 promotes neuropathic pain progression through the miR‑154‑5p/AQP9 axis in CCI rat models

The present study investigated the role and molecular mechanism of long non‑coding RNA (lncRNA) metastasis associated lung adenocarcinoma transcript (MALAT)1 in neuropathic pain in rat chronic constriction injury (CCI) model. Reverse transcription‑quantitative PCR and western blot analysis were used to detect the expression levels of MALAT1, microRNA (miR)‑154‑5p and aquaporin (AQP)9 in spinal cord tissue and microglia of CCI rats. ELISA and pain behavioral assays were used to observe the effect of MALAT1 on neuropathic pain and neuroinflammation in model rats, and to verify its molecular mechanism through bioinformatics and luciferase experiments. The results of the present study identified that the expression levels of MALAT1 and AQP9 were upregulated, while miR‑154‑5p was downregulated in spinal cord tissue and microglia of CCI rats. MALAT1 knockdown in CCI model rats significantly induced the occurrence of neuropathic pain, while the upregulation of miR‑154‑5p could reverse this process. The present study also identified that miR‑154‑5p was the target gene of MALAT1, and AQP9 was the target gene of miR‑154‑5p. AQP9 knockdown promoted the occurrence of neuropathic pain. In conclusion, lncRNA MALAT1 promotes the progression of neuropathic pain in rats by reducing miR‑154‑5p and increasing AQP9. The MALAT1/miR‑154‑5p/AQP9 axis can be used as a new therapeutic target for neuropathic pain.

Suppression of nicotinamide phosphoribosyltransferase expression by miR-154 reduces the viability of breast cancer cells and increases their susceptibility to doxorubicin

Background

Nicotinamide phosphoribosyltransferase (NAMPT) enzyme acts as the major enzyme in the nicotinamide adenine dinucleotide (NAD) synthesis salvage pathway. Deregulation of NAD could be associated with progression of several cancers such as breast cancer. Here, the consequence of NAMPT inhibition by miR-154 was investigated on breast cancer cells.

Methods

MDA-MB-231 and MCF-7 cancer cell lines were transfected with the mimic and inhibitors of miR-154-5p and their corresponding negative controls. Consequently, levels of NAMPT and NAD were assayed employing qRT-PCR, Western blotting and enzymatic method, respectively. Subsequently, flow cytometry and colorimetric methods were performed to evaluate apoptosis and cell viability. Bioinformatics analyses as well as luciferase assay were done to investigate whether the 3′-UTR of NAMPT is directly targeted by miR-154.

Results

According to the obtained results, NAMPT was recognized as a target for binding of miR-154 and the levels of this miRNA was inversely associated with both mRNA and protein levels of NAMPT in breast cancer cell lines. Functionally, miR-154 inhibited the NAD salvage pathway leading to a remarkable decrease in cell viability and increased rate of cell death. When breast cancer cells were simultaneously treated with doxorubicin and miR-154 mimic, cell viability was considerably reduced compared to treatment with doxorubicin alone in both cell lines.

Conclusions

It was concluded that the inhibition of NAD production by miR-154 might be introduced as an appropriate therapeutic approach in order to improve breast cancer outcome either alone or in combination with other conventional chemotherapeutic agents.

MicroRNA-152 suppresses cisplatin resistance in A549 cells

The present study aimed to investigate the association between microRNA-152 and cisplatin resistance in non-small cell lung cancer. A549 and cisplatin-resistant A549 cells (A549/cis) were maintained in vitro. Reverse transcription-quantitative PCR (RT-qPCR) was performed to analyze differences in microRNA-152 levels between A549 and A549/cis cells, and changes in Bcl-2 and NF-κB expression levels were analyzed via RT-qPCR and western blot analyses. MicroRNA-152 was overexpressed in A549/cis cells via transfection of a microRNA-152 mimic. Upon treating transfected or untransfected A549/cis cells with 2 µg/l cisplatin for 24 h, a Cell Counting Kit-8 assay, morphological analysis and flow cytometry analysis were performed to evaluate the effect of microRNA-152 on the inhibition of cell proliferation and induction of apoptosis. Furthermore, changes in Bcl-2 and NF-κB expression levels in microRNA-152-overexpressing A549/cis cells were also analyzed. MicroRNA-152 was significantly downregulated and Bcl-2 and NF-κB were significantly upregulated in A549/cis cells (P<0.05). MicroRNA-152 upregulation enhanced the inhibitory effect of cisplatin on A549/cis cells. These results suggest that microRNA-152 downregulates Bcl-2 and NF-κB. MicroRNA-152 downregulation may induce cisplatin resistance in non-small cell lung cancer cells, whereas microRNA-152 upregulation may improve cisplatin sensitivity among A549/cis cells via downregulation of Bcl-2 and NF-κB.

Correlation Between Serum miR-154-5p and Osteocalcin in Males and Postmenopausal Females of Type 2 Diabetes With Different Urinary Albumin Creatinine Ratios

Purpose: To investigate the serum levels of miR-154-5p, osteocalcin (OC), and other clinical parameters in male and post-menopausal female type 2 diabetes mellitus (T2DM) patients with different urinary albumin creatinine ratio (UACR) levels and to discuss the relationship between miR-154-5p and glycolipid metabolism, bone metabolism, and different urinary albumin excretion rate in T2DM. Methods: Seven hundred thirty-eight T2DM patients were categorized into six groups, including 374 men and 364 post-menopausal women who were sub-divided into three groups based on albumin excretion that involved normal albuminuria, microalbuminuria, and large amount of albuminuria (138, 127, 109, 135, 125, and 104 cases, UACR<30, 30-300, and >300 mg/g, M1, M2, M3, F1, F2, and F3). Measurement of circulating miR-154-5p, OC, and other biochemical indicators were performed by real-time PCR, ELISA, and chemiluminescence assays in T2DM patients and in 141 M0 and 139 F0 control subjects. Results: There are few differences appeared between groups. Comparing with men, women had higher age, waist-to-hip ratio (WHR), adiponectin (ADPN), connective tissue growth factor (CTGF), UACR, procollagen type 1 N-terminal propeptide (P1NP), β-C-terminal telopeptide of type I collagen (β-CTx), OC, and miR-154-5p, but lower FPG, HOMA-IR, and HbA1c. T2DM patients with albuminuria (micro or macro) had lower bone turnover markers (P1NP, β-CTx, and OC) and adiponectin, but higher HbA1c, CTGF, and miR-154-5p. In addition, after regression analysis, UACR was positively correlated with CTGF, HbA1c, and miR-154-5p, and negatively correlated with ADPN and bone turnover markers (P1NP, β-CTx, and OC). However, OC showed a positive correlation with ADPN and other bone turnover markers (P1NP and β-CTx), but negative correlation with CTGF, UACR, and miR-154-5p in all three groups. Conclusion: These findings suggested that increased serum levels of miR-154-5p and decreased OC levels may influence osteogenesis and proteinuria in T2DM and may identify novel targets for diagnosis and treatment of diabetic kidney disease and osteoporosis.

MicroRNA-154 Targets the Wnt/β-Catenin Signaling Pathway Following Injury to Human Vascular Endothelial Cells by Hydrogen Peroxide

Background

Endothelial cells are involved in vascular homeostasis, and endothelial cell dysfunction is involved in the pathogenesis of cardiovascular disease. This study aimed to investigate the effects of microRNA-154 in human umbilical vein endothelial cells (HUVECs) following injury induced by hydrogen peroxide (H₂O₂).

Material/Methods

Cell viability and apoptosis of HUVECs treated with H₂O₂ were measured. The expression of microRNA-154 was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell survival, caspase-3 activity, and the apoptosis rate were evaluated in H₂O₂-treated HUVECs cells after the upregulation and down-regulation of microRNA-154 expression. The interaction between microRNA-154 and Dickkopf WNT signaling pathway inhibitor 2 (DKK2) was predicted by bioinformatics analysis and was verified by luciferase reporter gene assay and Western blot. The effects of DKK2 short-interfering RNA (siRNA) on antioxidant injury in HUVECs cells were determined.

Results

The survival rate of HUVECs exposed to H₂O₂ was significantly reduced and the apoptosis rate was significantly increased, and H₂O₂ significantly inhibited the expression of microRNA-154 in a dose-dependent manner. Overexpression of microRNA-154 increased cell survival, reduced the activity of caspase-3, and reduced cell apoptosis. Inhibition of microRNA-154 expression decreased cell survival, increased the activity of caspase-3, and promoted cell apoptosis. Luciferase reporter gene assay and Western blot showed that microRNA-154 interacted with the Wnt pathway molecule DKK2 in HUVECS. Also, DDK2 siRNA resulted in a similar protective effect on H₂O₂-treated HUVECs as overexpression of microRNA-154.

Conclusions

Oxidative injury in HUVECs was regulated by microRNA-154 targeting the Wnt/β-catenin signaling pathway.

Current insights into functions of phospholipase A2 receptor in normal and cancer cells: More questions than answers

Lipid signaling network was proposed as a potential target for cancer prevention and treatment. Several recent studies revealed that phospholipid metabolising enzyme, phospholipase A2 (PLA₂), is a critical regulator of cancer accelerating pathologies and apoptosis in several types of cancers. In addition to functioning as an enzyme, PLA₂ can activate a phospholipase A2 receptor (PLA2R1) in plasma membrane. While the list of PLA₂ targets extends to glucose homeostasis, intracellular energy balance, adipocyte development, and hepatic lipogenesis, the PLA2R1 downstream effectors are few and scarcely investigated. Among the most addressed PLA2R1 effects are regulation of pro-inflammatory signaling, autoimmunity, apoptosis, and senescence. Localized in glomeruli podocytes, the receptor can be identified by circulating anti-PLA2R1 autoantibodies leading to development of membranous nephropathy, a strong autoimmune inflammatory cascade. PLA2R1 was shown to induce activation of Janus-kinase 2 (JAK2) and estrogen-related receptor α (ERRα)-controlled mitochondrial proteins, as well as increasing the accumulation of reactive oxygen species, thus leading to apoptosis and senescence. These findings indicate the potential role of PLA2R1 as tumor suppressor. Epigenetic investigations addressed the role of DNA methylation, histone modifications, and specific microRNAs in the regulation of PLA2R1 expression. However, involvement of PLA2R1 in suppression of malignant growth and metastasis remains controversial. In this review, we summarize the recent findings that highlight the role of PLA2R1 in the regulation of carcinogenesis-related intracellular signaling.

DNA methylation-regulated and tumor-suppressive roles of miR-487b in colorectal cancer via targeting MYC, SUZ12, and KRAS

Human colorectal cancer (CRC), characterized by its high morbidity and lethality, seriously threatens human health and lives. MicroRNA‐487b (miR‐487b) is currently reported to be aberrantly expressed in several tumors, but the detailed functions and underlying mechanisms of miR‐487b in CRC remain unclear. Here, we found that miR‐487b is downregulated in CRC cell lines and is markedly decreased in tumor specimens derived from CRC patients. MiR‐487b inhibits cell proliferation, migration and invasion and promotes the apoptosis of CRC cells in vitro. Statistical analysis of clinical samples indicates that miR‐487b may serve as a biomarker for early CRC diagnosis. Inverse correlations between the expression levels of MYC, SUZ12, and KRAS and that of miR‐487b exist in vitro and in CRC patient tissue specimens. Further experiments demonstrated the regulatory effects of miR‐487b on MYC, SUZ12, and KRAS, and the disruption of these genes partially restores the miR‐487b inhibitor‐induced phenotype. Additionally, miR‐487b promoter region is in a DNA hypermethylated condition and the DNA methyltransferase inhibitor 5‐aza‐2’‐deoxycytidine (5‐Aza) increases the levels of miR‐487b but suppresses the expression of MYC, SUZ12, and KRAS in a time‐ and concentration‐dependent manner in CRC cells. Collectively, miR‐487b is regulated by DNA methylation and it functions as a tumor suppressor in CRC mainly through targeting MYC, SUZ12, and KRAS. Our study provides insight into the regulatory network in CRC cells, offering a new target for treating CRC patients.

MicroRNA‑154 functions as a tumor suppressor in bladder cancer by directly targeting ATG7

Aberrant expression of miR‑154 is usually found in cancer studies; however, the role of miR‑154 has seldom been reported in bladder cancer (BCa). In this study, we observed that miR‑154 expression was significantly downregulated in BCa tissues and cell lines, and was associated with several clinicopathological characteristics, including advanced T stage, lymphatic invasion, and distant metastasis. Low expression level of miR‑154 was associated with poor survival outcomes in BCa patients. Overexpression of miR‑154 led to significant decrease in the proliferation, migration, and invasion of BCa cells, while knockdown of miR‑154 yielded the opposite effect. ATG7 was identified as a direct target of miR‑154. ATG7 expression was negatively correlated with miR‑154 expression in BCa tissues. Silencing of ATG7 achieved a similar effect to miR‑154 overexpression; overexpression of ATG7 reversed the inhibitory effect of miR‑154 on BCa cell proliferation, migration and invasion. A xenograft study revealed that miR‑154 inhibited BCa cell growth in vivo, and suppressed ATG7 expression. Altogether, this study demonstrated that miR‑154 may function as a tumor suppressor in BCa and indicated that miR‑154 may be a potential therapeutic target for BCa patients.

MiR-154 inhibits the growth of laryngeal squamous cell carcinoma by targeting GALNT7

MicroRNAs are critical regulators of the development and progression of laryngeal squamous cell carcinoma (LSCC). However, the role of microRNA-154 (miR-154) in the development and progression of LSCC has not been clarified. We found that down-regulated miR-154 expression in LSCC tissues was associated with poorer prognosis in LSCC patients. MiR-154 over-expression inhibited the proliferation, clonogenicity, and migration of LSCC cells and induced cell cycle arrest, which were reversed by miR-154 inhibition. MiR-154 targeted GALNT7 expression by reducing GALNT7-regulated luciferase activity in LSCC cells while up-regulating GALNT7 mRNA transcription in LSCC tissues and cells. GALNT7 silencing significantly attenuated the proliferation, clonogenicity, and migration of LSCC cells and induced cell cycle arrest. Finally, intravenous treatment with lentivirus for miR-154, but not scrambled control miRNA, significantly restrained the growth of implanted LSCC Hep-2 tumors and decreased the tumor mass by reducing GALNT7 expression in mice. Therefore, miR-154 may serve as a novel prognostic marker and therapeutic target for LSCC.

The long noncoding RNA SNHG1 regulates colorectal cancer cell growth through interactions with EZH2 and miR-154-5p

BACKGROUND

Mounting evidence demonstrates that long noncoding RNAs (lncRNAs) have critical roles during the initiation and progression of cancers. In this study, we report that the small nucleolar RNA host gene 1 (SNHG1) is involved in colorectal cancer progression.

METHODS

We analyzed RNA sequencing data to explore abnormally expressed lncRNAs in colorectal cancer. The effects of SNHG1 on colorectal cancer were investigated through in vitro and in vivo assays (i.e., CCK-8 assay, colony formation assay, flow cytometry assay, EdU assay, xenograft model, immunohistochemistry, and western blot). The mechanism of SNHG1 action was explored through bioinformatics, RNA fluorescence in situ hybridization, luciferase reporter assay, RNA pull-down assay, chromatin immunoprecipitation assay and RNA immunoprecipitation assay.

RESULTS

Our analysis revealed that SNHG1 was upregulated in human colorectal cancer tissues, and high SNHG1 expression was associated with reduced patient survival. We also found that high SNHG1 expression was partly induced by SP1. Moreover, SNHG1 knockdown significantly repressed colorectal cancer cells growth both in vitro and in vivo. Mechanistic investigations demonstrated that SNHG1 could directly interact with Polycomb Repressive Complex 2 (PRC2) and modulate the histone methylation of promoter of Kruppel like factor 2 (KLF2) and Cyclin dependent kinase inhibitor 2B (CDKN2B) in the nucleus. In the cytoplasm, SNHG1 acted as a sponge for miR-154-5p, reducing its ability to repress Cyclin D2 (CCND2) expression.

CONCLUSIONS

Taken together, the results of our studies illuminate how SNHG1 formed a regulatory network to confer an oncogenic function in colorectal cancer and suggest that SNHG1 may serve as a potential target for colorectal cancer diagnosis and treatment.

Oncogene miR-154-5p regulates cellular function and acts as a molecular marker with poor prognosis in renal cell carcinoma

AIMS

In adult population, the renal cell carcinoma (RCC) is one of the most common urological malignancies. It is meaningful to research for the molecular markers which are involved in the occurrence and development of RCC. Therefore, we concentrate on illuminating the role of microRNA-154-5p in progression of RCC and explore its prognostic values.

MAIN METHODS

The real-time quantitative polymerase chain reaction (RT-qPCR) was applied to determine expression level of miR-154-5p in tissues. Afterwards, the transfected cell lines ACHN and 786-O were used for the CCK-8 assay, MTT assay, wound healing assay, transwell assay and flow cytometric assay to explore the role of miR-154-5p in regulating cellular function. In addition, formalin-fixed paraffin-embedded (FFPE) renal cancer samples were used for detecting the relationship between expression level of miR-154-5p and clinical information. Furthermore, univariate and multivariate Cox proportional-hazards regression analyses, and the Kaplan-Meier survival curves were performed to evaluate the prognostic value of miR-154-5p in RCC.

KEY FINDINGS

The RT-qPCR indicated that miR-154-5p is up-regulated in RCC pathologic specimens and cell lines. Results of study also demonstrated that upregulation of miR-154-5p reduced cell apoptosis and promoted cell proliferation, viability, migration as well as invasion in RCC cells. The prognosis analyses indicated that the expression level of miR-154-5p is associated with the prognosis of renal cancer, and the overall survival of patients with low expression is longer.

SIGNIFICANCE

The present study revealed that the oncogene miR-154-5p regulates cellular function and acts as a molecular marker with poor prognosis in renal cell carcinoma.

MicroRNA-154 functions as a tumor suppressor in non-small cell lung cancer through directly targeting B-cell-specific Moloney murine leukemia virus insertion site 1

Lung cancer remains the leading cause of cancer-associated mortality in China and worldwide. Increasing numbers of studies have demonstrated that microRNAs (miRNAs/miRs) have vital functions in numerous developmental processes and tumorigenesis. The aim of the present study was to investigate miR-154 expression in non-small cell lung cancer (NSCLC), and to explore the roles of miR-154 in the carcinogenesis and progression of this cancer. Reverse transcription-polymerase chain reaction (RT-qPCR) was performed to detect miR-154 expression in NSCLC tissues and cell lines. In addition, cell proliferation assay, migration and invasion assays were adopted to investigate the functional roles of miR-154 in NSCLC. Bioinformatics analysis, luciferase reporter assay, RT-qPCR and western blot analysis were used to explore the potential targets of miR-154 in NSCLC. According to the results, miR-154 was significantly downregulated in NSCLC tissues and cell lines. Restoration of miR-154 expression inhibited proliferation, migration and invasion of NSCLC cells. In addition, B-cell-specific Moloney murine leukemia virus insertion site 1 (BMI-1) was identified as a direct target gene of miR-154 in NSCLC. In conclusion, miR-154 may function as a tumor suppressor in NSCLC, partly by regulating BMI-1, and the modulation of miR-154 expression represents a potential strategy for the treatment of NSCLC patients.

MicroRNA-154 as a prognostic factor in bladder cancer inhibits cellular malignancy by targeting RSF1 and RUNX2

Recent studies have demonstrated that microRNA-154 (miR-154) is involved in tumorigenesis, progression, invasion and metastasis in several types of human cancer. However, whether it plays a role in bladder cancer (BC) is unclear. The aim of the present study was to determine miR-154 levels in human BC tissues and investigate the correlation between miR-154 levels and clinicopathological characteristics as well as patient outcome. Using RT-qPCR, we found that the expression levels of miR-154 were significantly lower in BC tissues compared to adjacent normal tissues. We also demonstrated that downregulation of miR-154 was associated with advanced clinicopathological features and worse prognoses for patients with BC. Using a variety of integrated approaches, we demonstrated that both runt-related transcription factor 2 (RUNX2) and remodeling and spacing factor 1 (RSF1) were miR-154 targets. Notably, there was an inverse correlation between RSF1, RUNX2 and miR-154 expression in BC tissues. The biological functions of miR-154 were examined in vitro using Cell Counting Kit-8 (CCK-8), wound healing, and Transwell assays with T24 human bladder carcinoma cells transfected with miR-154 mimics or negative controls. These assays demonstrated that miR-154 significantly suppressed proliferation, migration and invasion of T24 cells (P<0.05). Furthermore, overexpression of RSF1 and RUNX2 rescued miR-154-induced inhibition of these aggressive behaviors. Our results indicated that miR-154, and its downstream targets RSF1 and RUNX2, are promising options for future BC therapies.

MicroRNA-154/ADAM9 axis inhibits the proliferation, migration and invasion of breast cancer cells

Breast cancer is the leading cause for cancer-associated mortality in women. Although great progress has been made in the earlier diagnosis and systemic therapy of patients with breast cancer in recent years, recurrence or distant metastasis continue to present major barriers to the successful treatment of breast cancer. Therefore, fully understanding the molecular mechanisms underlying the progression of breast cancer may be critical for the development of effective therapeutic strategies against breast cancer. The aim of the present study was to explore the expression, function and molecular mechanisms of microRNA-154 (miR-154) in human breast cancer. It was demonstrated that miR-154 was significantly downregulated in breast cancer tissue and cell lines. The restoration of miR-154 expression suppressed the proliferation, migration and invasion of breast cancer cells. ADAM metallopeptidase domain 9 (ADAM9) was identified as a novel direct target for miR-154 in breast cancer. It was demonstrated that miR-154 acted as a tumor suppressor in breast cancer by targeting ADAM9. The results of the present study suggest that the restoration of miR-154 expression may be an effective therapeutic strategy for the treatment of breast cancer in the future.

MicroRNA-154 inhibits the growth and metastasis of gastric cancer cells by directly targeting MTDH

MicroRNAs (miRNAs) are a group of non-protein-coding, highly conserved single-stranded RNA molecules. The abnormal expression of miRNAs has been demonstrated to have an important function in the carcinogenesis and progression of gastric cancer. microRNA-154 (miR-154) has been reported to be downregulated in non-small cell lung, colorectal and prostate cancer. However, the expression and roles of miR-154 in gastric cancer remain to be established. The present study measured the expression levels of miR-154 in gastric cancer tissues and cell lines. miR-154 was found to be significantly downregulated in gastric cancer tissues and cell lines. In addition, functional studies indicated that the overexpression of miR-154 inhibited the proliferation, migration and invasion of gastric cancer cells. Using TargetScan, a dual luciferase reporter assay, reverse transcription-quantitative polymerase chain reaction and western blot analysis, metadherin (MTDH) was revealed as a novel miR-154 target. In addition, knocking down MTDH lead to a similar effect as overexpressing-154 in gastric cells. The present findings indicate that miR-154 was downregulated in gastric cancer, and inhibited tumor behaviors of gastric cancer cells partially through the downregulation of MTDH. Therefore, the miR-154/MTDH axis may be a novel therapeutic to treat patients with gastric cancer.

MiRNA-154-5p inhibits cell proliferation and metastasis by targeting PIWIL1 in glioblastoma

MicroRNAs (miRNAs) play a critical role in glioblastoma initiation and progression. PIWIL1, a human homolog of the PIWI family, has a critical effect on glioblastoma progression. In present study, we found that the expression of miR-154-5p was significantly lower in glioblastoma. Our results suggested that the overexpression of miR-154-5p suppressed proliferation and metastasis, induced apoptosis, whereas inhibiting the expression of miR-154-5p significantly promoted proliferation and metastasis of glioblastoma. We further proved that miR-154-5p directly integrated with the 3'-UTR of PIWIL1 and reintroduction of PIWIL1 can rescue the phenotype changes induced by miR-154-5p. Taken together, our study reveals that miR-154-5p can counteract the malignant phenotypes of glioblastoma by targeting PIWIL1, which might be beneficial to reveal new therapeutic targets for glioblastoma.

MicroRNA-154 Inhibits the Growth and Invasion of Gastric Cancer Cells by Targeting DIXDC1/WNT Signaling

MicroRNAs (miRNAs) have emerged as pivotal regulators of the development and progression of gastric cancer. Studies have shown that miR-154 is a novel cancer-associated miRNA involved in various cancers. However, the role of miR-154 in gastric cancer remains unknown. Here we aimed to investigate the biological function and the potential molecular mechanism of miR-154 in gastric cancer. We found that miR-154 was significantly downregulated in gastric cancer tissues and cell lines. The overexpression of miR-154 significantly repressed the growth and invasion of gastric cancer cells. Bioinformatics analysis and Dual-Luciferase Reporter Assay data showed that miR-154 directly targeted the 3′-untranslated region of Dishevelled–Axin domain containing 1 (DIXDC1). Real-time quantitative polymerase chain reaction and Western blot analyses showed that miR-154 overexpression inhibited DIXDC1 expression. An inverse correlation of miR-154 and DIXDC1 was also demonstrated in gastric cancer specimens. Overexpression of miR-154 also significantly suppressed the activation of WNT signaling. Moreover, restoration of DIXDC1 expression significantly reversed the inhibitory effect of miR-154 overexpression on the cell proliferation, invasion, and WNT signaling in gastric cancer cells. Overall, these results suggest that miR-154 inhibits gastric cancer cell growth and invasion by targeting DIXDC1 and could serve as a potential therapeutic target for the treatment of gastric cancer.

miR-154 targeting ZEB2 in hepatocellular carcinoma functions as a potential tumor suppressor

MicroRNA-154 (miR-154) has been identified as a tumor suppressor in several types of human cancers; however, its clinical significance and function in human hepatocellular carcinoma (HCC) remain unclear. The aim of the present study was to analyze the clinical significance and cellular function of miR-154 in HCC patients. The data showed that miR-154 expression was consistently lower in HCC tissues and cell lines compared to that in matched tumor-adjacent tissues and a normal hepatic cell line, and its expression was negatively correlated with tumor differentiation (P<0.01), TNM stage (P<0.01) and lymph node metastasis (P<0.01). Restoration of miR-154 expression in HepG2 cells inhibited cell proliferation, migration and invasion, and induced apoptosis and cell arrest at the G1 phase in vitro, as well as suppressed tumor growth in a nude mouse model. Using a luciferase assay, we identified that miR-154 was able to target the 3'-untranslated region (3'UTR) of ZEB2 mRNA. Then, we revealed that miR-154 was able to reduce ZEB2 expression at the levels of mRNA and protein using qRT-PCR and western blot analysis. Notably, restoration of expression of ZEB2 weakened miR-154-mediated suppression of tumor progression. In conclusion, these results indicate that miR-154 functions as a tumor suppressor in HCC by suppressing ZEB2, suggesting that miR-154 may serve as a potential target for HCC.

Downregulation of miR-154 in human glioma and its clinicopathological and prognostic significance

Objective MicroRNA-154 (miR-154) was previously reported to be downregulated in several types of human cancers and may act as a tumour suppressor. This study aimed to measure miR-154 levels and determine its clinical significance in human glioma. Methods This retrospective study analysed fresh human glioma specimens and non-neoplastic brain tissues using real-time quantitative reverse transcription-polymerase chain reaction to determine the relative levels of miR-154. The association between miR-154 levels and various clinicopathological characteristics and survival was analysed. Results A total of 115 patients with gliomas and 115 non-neoplastic brain tissues were examined. MiR-154 levels were significantly downregulated in gliomas compared with non-neoplastic brain tissues. Low levels of miR-154 were associated with high World Health Organization grade, large tumour size (≥ 5 cm), a low Karnofsky performance status score (< 80), and a shorter overall survival. Multivariate analyses using the Cox proportional hazards regression model confirmed that decreased miR-154 level was an independent predictor of a poor prognosis. Conclusions These results suggest that miR-154 downregulation may be involved in glioma formation and progression, and that miR-154 might serve as a potential prognostic biomarker for patients with this disease.

Eritoran Suppresses Colon Cancer by Altering a Functional Balance in Toll-like Receptors That Bind Lipopolysaccharide

Colorectal carcinogenesis is affected by overexpression of the lipopolysaccharide (LPS) receptors CD14 and TLR4, which antagonize each other by affecting epithelial cell proliferation and apoptosis. Eritoran is an investigational drug for sepsis treatment that resembles the lipid A moiety of LPS and therefore acts as a TLR4 inhibitor. In the present study, we explored the potential therapeutic uses and mechanisms of action of eritoran in reducing colon cancer progression. Eritoran administration via intracolonic, intragastric, or intravenous routes significantly reduced tumor burden in a chemically induced mouse model of colorectal carcinoma. Decreased proliferation and increased apoptosis were observed in mouse tumor cells after eritoran treatment. In vitro cultures of mouse primary tumor spheroids and human cancer cell lines displayed increased cell proliferation and cell-cycle progression following LPS challenge. This effect was inhibited by eritoran and by silencing CD14 or TLR4. In contrast, apoptosis induced by eritoran was eliminated by silencing CD14 or protein kinase Cζ (PKCζ) but not TLR4. Lastly, LPS and eritoran caused hyperphosphorylation of PKCζ in a CD14-dependent and TLR4-independent manner. Blocking PKCζ activation by a Src kinase inhibitor and a PKCζ-pseudosubstrate prevented eritoran-induced apoptosis. In summary, our work offers a preclinical proof of concept for the exploration of eritoran as a clinical treatment, with a mechanistic rationale to reposition this drug to improve the management of colorectal cancer. Cancer Res; 76(16); 4684-95. ©2016 AACR.

miR-154 inhibits migration and invasion of human non-small cell lung cancer by targeting ZEB2

Emerging evidence suggests that microRNAs (miRs) play critical roles in the development and progression of non-small cell lung cancer (NSCLC). In a previous study, the present authors demonstrated that miR-154 acts as a tumor suppressor in NSCLC; however, its underlying molecular mechanism and target in NSCLC remain poorly understood. In the present study, ectopic expression of miR-154 remarkably suppressed cell migration and invasion in NSCLC cells. Zinc finger E-box binding homeobox 2 (ZEB2) was identified as a direct target of miR-154 in NSCLC cells. Furthermore, overexpression of miR-154 could decrease the expression of ZEB2 at the messenger RNA and protein levels. Ectopic expression of miR-154 also increased the levels of E-cadherin, an epithelial marker, and decreased the levels of vimentin, a mesenchymal marker, which contributed to suppress epithelial-mesenchymal transition (EMT) and to inhibit cell migration and invasion. In addition, downregulation of ZEB2 exerted similar effects to those caused by miR-154 overexpression on NSCLC cell migration and invasion, while upregulation of ZEB2 could significantly reverse the inhibitory effects on migration and invasion caused by miR-154 on NSCLC cells. These findings demonstrated that miR-154 inhibited migration and invasion of NSCLC cells by regulating EMT through targeting ZEB2, suggesting that miR-154 may be a potential anticancer therapeutic target for NSCLC.

The Upregulation of Genomic Imprinted DLK1-Dio3 miRNAs in Murine Lupus Is Associated with Global DNA Hypomethylation

Epigenetic factors such as DNA methylation and microRNAs (miRNAs) are now increasingly recognized as vital contributors to lupus etiology. In this study, we investigated the potential interaction of these two epigenetic factors in lupus-prone MRL-lpr mice. We recently reported dysregulated expression of miRNAs in splenocytes of MRL-lpr mice. Here, we report that a majority of the upregulated miRNAs in MRL-lpr mice is located at the genomic imprinted DLK1-Dio3 domain. Further, we show a differential magnitude of upregulation of DLK1-Dio3 miRNA cluster in purified splenic CD4+ T, CD19+ B, and splenic CD4-CD19- cells from MRL-lpr lupus mice when compared to control MRL mice. MRL-lpr splenocytes (especially CD19+ and CD4-CD19- subsets) were hypomethylated compared to cells from control, MRL mice. We further show that deliberate demethylation of splenocytes from control MRL mice, but not from MRL-lpr lupus mice, with specific DNA methylation inhibitor 5-Aza-2'-deoxycytidine significantly augmented DLK1-Dio3 miRNAs expression. These findings strongly indicate that the upregulation of DLK1-Dio3 miRNAs in lupus splenic cell subsets is associated with reduced global DNA methylation levels in lupus cells. There was a differential upregulation of DLK-Dio3 miRNAs among various demethylated splenic cell subsets, which implies varied sensitivity of DLK1-Dio3 miRNA cluster in these cell subsets to DNA hypomethylation. Finally, inhibition of select DLK1-Dio3 miRNA such as miR-154, miR-379 and miR-300 with specific antagomirs significantly reduced the production of lupus-relevant IFNγ, IL-1β, IL-6, and IL-10 in lipopolysaccharide (LPS) activated splenocytes from MRL-lpr mice. Our study is the first to show that DNA methylation regulates genomic imprinted DLK1-Dio3 miRNAs in autoimmune lupus, which suggests a connection of DNA methylation, miRNA and genomic imprinting in lupus pathogenesis.

MicroRNA-154 functions as a tumor suppressor in osteosarcoma by targeting Wnt5a

MicroRNAs (miRNAs) are small non-coding RNAs that are involved in tumor initiation and development by suppressing target gene expression. miRNA-154 has been shown to be important in tumorigenesis in many types of cancers. However, its role in osteosarcoma (OS) remains unknown. In the present study, we focused on the roles and mechanisms of miR‑154 in OS development. The results of quantitative RT‑PCR showed that miR‑154 expression was decreased in primary OS tumor samples and cell lines compared to levels in the matched adjacent normal tissues and human normal osteoblast cells (NHOst). Restoration of expression in U2OS cells inhibited cell proliferation, colony formation, migration and invasion, as well as induced cell cycle arrest at the G1 stage. Bioinformatic prediction suggested that Wnt5a is a target gene of miR‑154. It was further verified that Wnt5a is a target gene of miR‑150 in OS cells using luciferase assay, mRNA and protein expression analysis. Wnt5a was upregulated in OS cell lines and primary tumor samples, and its mRNA expression level was negatively correlated with the miR‑154 level in the OS tissues. Restored expression of Wnt5a weakened miR‑154‑mediated suppression of tumor progression. Taken together, these findings suggest that miR‑154 functions as a tumor suppressor in OS by partially suppressing Wnt5a expression.

Novel Association of miR-451 with the Incidence of TEVG Stenosis in a Murine Model

The development of a tissue-engineered vascular graft (TEVG) holds great promise for advancing the field of cardiac surgery. Despite the successful translation of this technology, previous reports identify the primary mode of graft failure as stenosis secondary to intimal hyperplasia. MicroRNAs (miRNAs) regulate gene expression by interfering with mRNA function and recent research has suggested miRNA as a potential therapeutic target. The role of miRNAs in TEVGs during neotissue formation is currently unknown. In this study, we investigated if miRNAs regulate the inhibition of graft stenosis. Biodegradable PGA-P(LA/CL) scaffolds were implanted as inferior vena cava interposition grafts in a murine model (n = 14). Mice were sacrificed 14 days following implantation and TEVGs were harvested for histological analysis and miRNA profiling using Affymetrix miRNA arrays. Graft diameters were measured histologically, and the largest grafts (patent group) and smallest grafts (stenosed group) were profiled (n = 4 for each group). Cell population in each graft was analyzed with immunohistochemistry using antismooth muscle actin (SMA) and antimacrophage (F4/80) antibodies. The graft diameter was significantly greater in the patent group (0.63 ± 0.06 mm) than in the stenosed group (0.17 ± 0.06 mm) (p < 0.01). Cell proliferation was significantly greater in the stenosed grafts than in patent grafts (p < 0.01: SMA [187 ± 11 vs. 77 ± 8 cells] vs. p = 0.025: F4/80 [245 ± 23 vs. 187 ± 11 cells]). MiRNA array of 1416 genes showed that in stenosed grafts, mir-451, mir-338, and mir-466 were downregulated and mir-154 was upregulated. Mir-451 exhibited the greatest difference in expression between stenosed and patent grafts by -3.1-fold. Significant negative correlation was found between the expression of mir-451 and cell proliferation (SMA: r = -0.86, p = 0.003; F4/80: r = -0.89, p = 0.001). Our data, along with previous evidence that mir-451 regulates tumor suppressor genes, suggest that downregulation of mir-451 promotes acute proliferation of macrophages and smooth muscle cells, thereby inducing TEVG stenosis. Adequate expression of mir-451 may be critical for improving TEVG patency.

Epigenetic control of phospholipase A2 receptor expression in mammary cancer cells

BACKGROUND

It has recently been proposed that the M-type phospholipase A2 receptor (PLA2R1) acts as a tumour suppressor in certain malignancies including mammary cancer. Considering that DNA methylation is an important regulator of gene transcription during carcinogenesis, in the current study we analyzed the PLA2R1 expression, PLA2R1 promoter methylation, and selected micro RNA (miRNA) levels in normal human mammary epithelial cells (HMEC) and cancer cell lines.

METHODS

Levels of PLA2R1 and DNA methyltransferases (DNMT) specific mRNA were determined using real-time RT-PCR. Methylation specific-high resolution melting (MS-HRM) analysis was utilized to quantify the methylation degree of selected CpG sites localized in the promoter region of the PLA2R1 gene. Expression of miRNA was tested using miScript Primer Assay system.

RESULTS

Nearly complete methylation of the analyzed PLA2R1 promoter region along with PLA2R1 gene silencing was identified in MDA-MB-453 mammary cancer cells. In MCF-7 and BT-474 mammary cancer cell lines, a higher DNA methylation degree and reduced PLA2R1 expression were found in comparison with those in normal HMEC. Synergistic effects of demethylating agent (5-aza-2'-deoxycytidine) and histone deacetylase inhibitor (trichostatin A) on PLA2R1 transcription in MDA-MB-453 cells confirmed the importance of DNA methylation and histone modification in the regulation of the PLA2R1 gene expression in mammary cells. Furthermore, significant positive correlation between the expression of DNMT1 and PLA2R1 gene methylation and negative correlation between the cellular levels of hsa-mir-141, -181b, and -181d-1 and the expression of PLA2R1 were identified in the analyzed cells. Analysis of combined z-score of miR-23b, -154 and -302d demonstrated a strong and significant positive correlation with PLA2R1 expression.

CONCLUSIONS

Our data indicate that (i) PLA2R1 expression in breast cancer cells is controlled by DNA methylation and histone modifications, (ii) hypermethylation of the PLA2R1 promoter region is associated with up-regulation of DNMT1, and (iii) hsa-miR-23b, -154, and -302d, as well as hsa-miR-141, -181b, and -181d-1 are potential candidates for post-transcriptional regulation of PLA2R1 expression in mammary cancer cells.

MiR-154-5p regulates osteogenic differentiation of adipose-derived mesenchymal stem cells under tensile stress through the Wnt/PCP pathway by targeting Wnt11

Mechanical stress is a well-acknowledged positive regulatory factor for osteogenic differentiation of adipose- derived mesenchymal stem cells (ADSCs). However, the molecular mechanisms associated with micro-RNAs (miRNAs) whereby ADSCs respond to mechanical stimuli remain elusive. We investigated the mechanism of mechanotransduction from the miRNA perspective in the osteogenic differentiation of ADSCs under tensile stress. Microarray analysis showed that miR-154-5p was remarkably downregulated when ADSCs were subjected to mechanical tension. Bioinformatics analysis with luciferase reporter assays demonstrated that Wnt11 3'UTR was a new direct target of miR-154-5p. Under tensile stress, lentivirus-mediated gain- or loss-of-function studies revealed that forced expression of miR-154-5p inhibited osteogenic differentiation of ADSCs, whereas inhibition of endogenous miR-154-5p with its antisense oligonucleotide (ASO-154-5p) obviously promoted osteogenic differentiation. Furthermore, miR-154-5p overexpression decreased activity of the non-canonical Wnt/PCP (RhoA-ROCK) pathway, as indicated by lower expression of Wnt11, active RhoA and ROCKII in miR-154-5p-treated ADSCs. By contrast, miR-154-5p inhibition activated the Wnt/PCP signals. Taken together, these results demonstrate that, under tensile stress, miR-154-5p negatively regulates ADSCs osteogenic differentiation through the Wnt/PCP pathway by directly targeting Wnt11. This novel regulatory pathway provides new insights into the molecular mechanism of mechanotransduction in osteogenic differentiation of ADSCs.

MiR-375 targets KLF4 and impacts the proliferation of colorectal carcinoma

MiR-375 has been identified as oncogenes or tumor suppressor genes which has the potential to the development and growth of cancers. However, the limited information concerning the expression and role of miR-375 in colorectal cancer (CRC) is available. In this work, we provide evidence for a function of miR-375 in the inhibition of CRC proliferation. Here, we showed that miR-375, down-modulated in human colorectal cancer tissues compared with normal human colon tissues, including several colorectal cancer cell lines. Subsequently, using the luciferase reporter assays, we found that the KLF4 untranslated region (3'UTR) carries the direct binding site of miR-375. In terms of function in vitro, CCK-8 assay, colony formation assay, and cell cycle assay demonstrated that the overexpression of miR-375 suppressed CRC cell proliferation. Inhibition of KLF4 performed similar effects with miR-375 overexpression on CRC cells, and overexpression of KLF4 could significantly reverse the tumor suppressive effects of miR-375 on CRC cells. Furthermore, we found overexpressed miR-375 effectively repressed tumor growth via KLF4 in xenograft animal experiment. Taken together, these results illustrated that miR-375 depresses proliferation of CRC through regulating 3'UTR of KLF4 mRNA, which might be a promising therapeutic target for treating colorectal cancers.

Decreased miR-154 expression and its clinical significance in human colorectal cancer

Background

miRNA-154 (miR-154) has been identified as a tumor suppressor in several types of human cancers. However, its clinical significance in colorectal cancer (CRC) is still unclear. The aim of this study was to analyze the association of miR-154 expression with clinicopathologic features and prognosis in CRC patients.

Methods

Quantitative RT-PCR was performed to evaluate miR-154 levels in 169 pairs of CRC specimens and adjacent noncancerous tissues. Then, the associations of miR-154 expression with clinicopathological factors or survival of patients suffering CRC were determined.

Results

The expression levels of miR-154 in CRC tissues were significantly lower than those in corresponding noncancerous tissues (P < 0.001). Decreased miR-154 expression was significantly associated with large tumor size, positive lymph node metastasis, and advanced clinical stage. Moreover, the univariate analysis demonstrated that CRC patients with low miR-154 expression had poorer overall survival (P = 0.006). The multivariate analysis identified low miR-154 expression as an independent predictor of poor survival.

Conclusions

These findings suggested that miR-154 downregulation may be associated with tumor progression of CRC, and that this miR may be an independent prognostic marker for CRC patients.

Human Cytomegalovirus miR-UL112-3p Targets TLR2 and Modulates the TLR2/IRAK1/NFκB Signaling Pathway

Human Cytomegalovirus (HCMV) encodes multiple microRNAs (miRNAs) whose functions are just beginning to be uncovered. Using in silico approaches, we identified the Toll-Like Receptor (TLR) innate immunity pathway as a possible target of HCMV miRNAs. Luciferase reporter assay screens further identified TLR2 as a target of HCMV miR-UL112-3p. TLR2 plays a major role in innate immune response by detecting both bacterial and viral ligands, including HCMV envelope proteins gB and gH. TLR2 activates a variety of signal transduction routes including the NFκB pathway. Furthermore, TLR2 plays an important role in controlling CMV infection both in humans and in mice. Immunoblot analysis of cells transfected with a miR-UL112-3p mimic revealed that endogenous TLR2 is down-regulated by miR-UL112-3p with similar efficiency as a TLR2-targeting siRNA (siTLR2). We next found that TLR2 protein level decreases at late times during HCMV infection and correlates with miR-UL112-3p accumulation in fibroblasts and monocytic THP1 cells. Confirming direct miR-UL112-3p targeting, down-regulation of endogenous TLR2 was not observed in cells infected with HCMV mutants deficient in miR-UL112-3p expression, but transfection of miR-UL112-3p in these cells restored TLR2 down-regulation. Using a NFκB reporter cell line, we found that miR-UL112-3p transfection significantly inhibited NFκB-dependent luciferase activity with similar efficiency as siTLR2. Consistent with this observation, miR-UL112-3p transfection significantly reduced the expression of multiple cytokines (IL-1β, IL-6 and IL-8) upon stimulation with a TLR2 agonist. Finally, miR-UL112-3p transfection significantly inhibited the TLR2-induced post-translational activation of IRAK1, a kinase located in the upstream section of the TLR2/NFκB signaling axis. To our knowledge, this is the first identified mechanism of TLR2 modulation by HCMV and is the first report of functional targeting of TLR2 by a viral miRNA. These results provide a novel mechanism through which a HCMV miRNA regulates the innate immune response by down-regulating TLR-2 expression.

miR-154 suppresses non-small cell lung cancer growth in vitro and in vivo

miR-154 has been proven to act as a tumor suppressor in several types of tumors. However, its role in non-small cell lung cancer (NSCLC) remains unclear. Thus, the aim of this study was to investigate the effects of miR-154 on NSCLC tumorigenesis and development. Using real-time quantitative PCR (qRT-PCR), we analyzed expression of miR-154 at the transcriptional level in 40 NSCLC tumor tissues and matched adjacent normal tissues and the correlation with clinicopathological features of the patients. The miR-154 mimic was stably transfected into NSCLC A549 cells, and the effects of miR-154 on cancer cell proliferation, colony formation, cell cycle arrest, apoptosis, migration and invasion in vitro, and on the growth of in vivo xenografts were investigated. miR-154 expression levels were significantly downregulated in the NSCLC compared to the corresponding non-cancerous lung tissues (P<0.05), and decreased miR-154 expression was significantly associated with metastasis (P<0.001), larger tumor size (P<0.001) and advanced TNM stage (P<0.001). Furthermore, transfection of the miR-154 mimic into the NSCLC A549 cells was able to inhibit cell proliferation, colony formation, invasion and migration, and induce cell apoptosis and G0/G1 cell cycle arrest. Enforced expression of miR-154 also suppressed the growth of cancer cell xenografts in vivo. These findings indicate that miR-154 may become a potential target for miR-based therapy of NSCLC.

Transmitted/founder hepatitis C viruses induce cell-type- and genotype-specific differences in innate signaling within the liver

Hepatitis C virus (HCV) infection leads to persistence in the majority of cases despite triggering complex innate immune responses within the liver. Although hepatocytes are the preferred site for HCV replication, nonparenchymal cells (NPCs) can also contribute to antiviral immunity. Recent innovations involving single-genome amplification (SGA), direct amplicon sequencing, and phylogenetic inference have identified full-length transmitted/founder (T/F) viruses. Here, we tested the effect of HCV T/F viral RNA (vRNA) on innate immune signaling within hepatocytes and NPCs, including the HepG2 and Huh 7.5.1 cell lines, a human liver endothelial cell line (TMNK-1), a plasmacytoid dendritic cell line (GEN2.2), and a monocytic cell line (THP-1). Transfection with hepatitis C T/F vRNA induced robust transcriptional upregulation of type I and III interferons (IFNs) within HepG2 and TMNK-1 cells. Both the THP-1 and GEN2.2 lines demonstrated higher type I and III IFN transcription with genotype 3a compared to genotype 1a or 1b. Supernatants from HCV T/F vRNA-transfected TMNK-1 cells demonstrated superior viral control. Primary human hepatocytes (PHH) transfected with genotype 3a induced canonical pathways that included chemokine and IFN genes, as well as overrepresentation of RIG-I (DDX58), STAT1, and a Toll-like receptor 3 (TLR3) network. Full-length molecular clones of HCV induce broad IFN responses within hepatocytes and NPCs, highlighting that signals imparted by the various cell types within the liver may lead to divergent outcomes of infection. In particular, the finding that HCV genotypes differentially induce antiviral responses in NPCs and PHH might account for relevant clinical-epidemiological observations (higher clearance but greater necroinflammation in persistence with genotype 3).

IMPORTANCE

Hepatitis C virus (HCV) has become a major worldwide problem, and it is now the most common viral infection for which there is no vaccine. HCV infection often leads to persistence of the virus and is a leading cause of chronic hepatitis, liver cancer, and cirrhosis. There are multiple genotypes of the virus, and patients infected with different viral genotypes respond to traditional therapy differently. However, the immune response to the virus within the liver has not been fully elucidated. Here, we determined the responses to different genotypes of HCV in cell types of the liver. We found that the immune response varied according to both cell type and HCV genotype, leading to a more pronounced induction of inflammatory pathways after exposure to certain genotypes. Therefore, inflammatory pathways that are being robustly activated by certain HCV genotypes could lead to more severe damage to the liver, inducing diverse outcomes and responses to therapy.

MiR-152 suppresses the proliferation and invasion of NSCLC cells by inhibiting FGF2

MicroRNAs (miRNAs) regulate the proliferation and metastasis of cancer cells. Here, we showed that miR-152 was downregulated in non-small-cell lung cancer (NSCLC) tissues and cell lines. Overexpression of miR-152 suppressed cell proliferation and colony formation and also limited migration and invasion. Fibroblast growth factor 2 (FGF2) was confirmed as a direct target of miR-152. FGF2 knockdown suppressed cell proliferation, colony formation, migration and invasion, whereas FGF2 overexpression partially reversed the suppressive effect of miR-152. Furthermore, the presence of miR-152 was inversely correlated with FGF2 in NSCLC tissues. Overall, this study demonstrated that miR-152 suppressed the proliferation and invasion of NSCLC cells by downregulating FGF2. These findings provide novel insights with potential therapeutic applications for the treatment of NSCLC.

Towards a molecular basis of oligometastatic disease: potential role of micro-RNAs

Oligometastasis is a cancer disease state characterized by a limited number of metastatic tumors involving single or few organs and with biological properties that make them potentially amenable to locoregional antitumor therapy. Current clinical data show that they are potentially curable with surgical resection or/and radiotherapy. Yet, mechanisms of progression from primary tumor to oligometastasis, rather than to polymetastases, is lacking in detail. In the current review we focus on the role of micro-RNAs in the regulation of metastases development and the role they may play in the differentiation of oligometastatic from polymetastatic progression. We also discuss the analyses of metastatic samples from oligo-and polymetastatic patients, which suggest that oligometastasis is a distinct biologic entity regulated in part by micro-RNAs. In addition, a review of the known functions of oligometastatic-specific micro-RNAs suggest that they regulate multiple steps in the metastatic cascade, including epithelial–mesenchymal transition, tumor invasion, intravasation, distant vascular extravasation and proliferation in a distant organ. Understanding the role of micro-RNAs and their target genes in oligometastatic disease may allow for the development of targeted therapies to effectively conrol the spread of metastases.

MiR-145 inhibits osteosarcoma cells proliferation and invasion by targeting ROCK1

MicroRNAs (miRNAs) contribute to the development and progression of various types of human cancers. The aim of this study was to study the role of miR-145 and to identify its functional target gene in osteosarcoma (OS) cells. We found that miR-145 was reduced in OS tissues and cell lines. Enforced expression of miR-145 inhibited cell proliferation, migration, and invasion abilities of MG-63 cells. Furthermore, we revealed that Rho-associated protein kinase 1 (ROCK1) was a target of miR-145 in OS. Finally, we found that silencing of ROCK1 performed similar effects with miR-145 in MG-63 cells, and ROCK1 was inversely correlated with miR-145 in OS tissues. Collectively, these data indicate that miR-145 may act as a tumor suppressor and contributes to the progression of OS through targeting ROCK1.