hsa-miR-135a-1 inhibits prostate cancer cell growth and migration by targeting EGFR

Emerging role of miRNA in prostate cancer: A future era of diagnostic and therapeutics

Prostate cancer (PCa) is the most common cancer in men (20%) and is responsible for 6.8% (1/5) of all cancer-related deaths in men around the world. The development and spread of prostate cancer are driven by a wide variety of genomic changes and extensive epigenetic events. Because of this, the MicroRNA (miRNA) and associated molecular mechanisms involved in PCa genesis and aggressive were only partially identified until today. The miRNAs are a newly discovered category of regulatorsthat have recently been recognized to have a significant role in regulating numerous elements of cancer mechanisms, such as proliferation, differentiation, metabolism, and apoptosis. The miRNAs are a type of small (22-24 nucleotides), non-coding, endogenous, single-stranded RNA and work as potent gene regulators. Various types of cancer, including PCa, have found evidence that miRNA genes, which are often located in cancer-related genetic regions or fragile locations, have a role in the primary steps of tumorigenesis, either as oncogenes or tumorsuppressors. To explain the link between miRNAs and their function in the initiation and advancement of PCa, we conducted a preliminary assessment. The purpose of this research was to enhance our understanding of the connection between miRNA expression profiles and PCa by elucidating the fundamental processes of miRNA expression and the target genes.

The Bone Microenvironment Soil in Prostate Cancer Metastasis: An miRNA Approach

Bone metastatic prostate cancer (PCa) is associated with a high risk of mortality. Changes in the expression pattern of miRNAs seem to be related to early aspects of prostate cancer, as well as its establishment and proliferation, including the necessary steps for metastasis. Here we compiled, for the first time, the important roles of miRNAs in the development, diagnosis, and treatment of bone metastasis, focusing on recent in vivo and in vitro studies. PCa exosomes are proven to promote metastasis-related events, such as osteoblast and osteoclast differentiation and proliferation. Aberrant miRNA expression in PCa may induce abnormal bone remodeling and support tumor development. Furthermore, miRNAs are capable of binding to multiple mRNA targets, a dynamic property that can be harnessed for the development of treatment tools, such as antagomiRs and miRNA mimics, which have emerged as promising candidates in PCa treatment. Finally, miRNAs may serve as noninvasive biomarkers, as they can be detected in tissue and bodily fluids, are highly stable, and show differential expression between nonmetastatic PCa and bone metastatic samples. Taken together, the findings underscore the importance of miRNA expression profiles and miRNA-based tools as rational technologies to increase the quality of life and longevity of patients.

MicroRNAs as biomarkers for early diagnosis, targeting and prognosis of prostate cancer

Globally, prostate cancer (PC) is leading cause of cancer-related mortality in men worldwide. Despite significant advances in the treatment and management of this disease, the cure rates for PC remains low, largely due to late detection. PC detection is mostly reliant on prostate-specific antigen (PSA) and digital rectal examination (DRE); however, due to the low positive predictive value of current diagnostics, there is an urgent need to identify new accurate biomarkers. Recent studies support the biological role of microRNAs (miRNAs) in the initiation and progression of PC, as well as their potential as novel biomarkers for patients' diagnosis, prognosis, and disease relapse. In the advanced stages, cancer-cell-derived small extracellular vesicles (SEVs) may constitute a significant part of circulating vesicles and cause detectable changes in the plasma vesicular miRNA profile. Recent computational model for the identification of miRNA biomarkers discussed. In addition, accumulating evidence indicates that miRNAs can be utilized to target PC cells. In this article, the current understanding of the role of microRNAs and exosomes in the pathogenesis and their significance in PC prognosis, early diagnosis, chemoresistance, and treatment are reviewed.

Loss of miR-936 leads to acquisition of androgen-independent metastatic phenotype in prostate cancer

Prostate cancer (PCa) progresses from a hormone-sensitive, androgen-dependent to a hormone-refractory, androgen-independent metastatic phenotype. Among the many genes implicated, ANXA2, a calcium-dependent phospholipid binding protein, has been found to have a critical role in the progression of PCa into more invasive metastatic phenotype. However, the molecular mechanisms underlying the absence of ANXA2 in early PCa and its recurrence in advanced stage are yet unknown. Moreover, recent studies have observed the deregulation of microRNAs (miRNAs) are involved in the development and progression of PCa. In this study, we found the down-regulation of miR-936 in metastatic PCa wherein its target ANXA2 was overexpressed. Subsequently, it has been shown that the downregulation of miRNA biogenesis by siRNA treatment in ANXA2-null LNCaP cells could induce the expression of ANXA2, indicating the miRNA mediated regulation of ANXA2 expression. Additionally, we demonstrate that miR-936 regulates ANXA2 expression by direct interaction at coding as well as 3'UTR region of ANXA2 mRNA by luciferase reporter assay. Furthermore, the overexpression of miR-936 suppresses the cell proliferation, cell cycle progression, cell migration, and invasion abilities of metastatic PCa PC-3 cells in vitro and tumor forming ability in vivo. These results indicate that miR-936 have tumor suppressor properties by regulating the over expression of ANXA2 in hormone-independent metastatic PCa. Moreover, our results suggest that this tumor suppressor miR-936 could be developed as a targeted therapeutic molecule for metastatic PCa control and to improve the prognosis in PCa patients.

Targeting Protein Kinases and Epigenetic Control as Combinatorial Therapy Options for Advanced Prostate Cancer Treatment

Prostate cancer (PC), the fifth leading cause of cancer-related mortality worldwide, is known as metastatic bone cancer when it spreads to the bone. Although there is still no effective treatment for advanced/metastatic PC, awareness of the molecular events that contribute to PC progression has opened up opportunities and raised hopes for the development of new treatment strategies. Androgen deprivation and androgen-receptor-targeting therapies are two gold standard treatments for metastatic PC. However, acquired resistance to these treatments is a crucial challenge. Due to the role of protein kinases (PKs) in the growth, proliferation, and metastases of prostatic tumors, combinatorial therapy by PK inhibitors may help pave the way for metastatic PC treatment. Additionally, PC is known to have epigenetic involvement. Thus, understanding epigenetic pathways can help adopt another combinatorial treatment strategy. In this study, we reviewed the PKs that promote PC to advanced stages. We also summarized some PK inhibitors that may be used to treat advanced PC and we discussed the importance of epigenetic control in this cancer. We hope the information presented in this article will contribute to finding an effective treatment for the management of advanced PC.

MicroRNA-16 Restores Sensitivity to Tyrosine Kinase Inhibitors and Outperforms MEK Inhibitors in KRAS-Mutated Non-Small Cell Lung Cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) is the leading cause of cancer death worldwide. Chemotherapy, the treatment of choice in non-operable cases, achieves a dismal success rate, raising the need for new therapeutic options. In about 25% of NSCLC, the activating mutations of the KRAS oncogene define a subclass that cannot benefit from tyrosine kinase inhibitors (TKIs). The tumor suppressor miR-16 is downregulated in many human cancers, including NSCLC. The main objectives of this study were to evaluate miR-16 treatment to restore the TKI sensitivity and compare its efficacy to MEK inhibitors in KRAS-mutated NSCLC.

METHODS

We performed in vitro and in vivo studies to investigate whether miR-16 could be exploited to overcome TKI resistance in KRAS-mutated NSCLC. We had three goals: first, to identify the KRAS downstream effectors targeted by mir-16, second, to study the effects of miR-16 restoration on TKI resistance in KRAS-mutated NSCLC both in vitro and in vivo, and finally, to compare miR-16 and the MEK inhibitor selumetinib in reducing KRAS-mutated NSCLC growth in vitro and in vivo.

RESULTS

We demonstrated that miR-16 directly targets the three KRAS downstream effectors MAPK3, MAP2K1, and CRAF in NSCLC, restoring the sensitivity to erlotinib in KRAS-mutated NSCLC both in vitro and in vivo. We also provided evidence that the miR-16-erlotinib regimen is more effective than the selumetinib-erlotinib combination in KRAS-mutated NSCLC.

CONCLUSIONS

Our findings support the biological preclinical rationale for using miR-16 in combination with erlotinib in the treatment of NSCLC with KRAS-activating mutations.

MicroRNAs as the critical regulators of protein kinases in prostate and bladder cancers

Background

Bladder cancer (BCa) and prostate cancer (PCa) are frequent urothelial and genital malignancies with a high ratio of morbidity and mortality which are more common among males. Since BCa and PCa cases are mainly diagnosed in advanced stages with clinical complications, it is required to introduce the efficient early detection markers. Protein kinases are critical factors involved in various cellular processes such as cell growth, motility, differentiation, and metabolism. Deregulation of protein kinases can be frequently observed through the neoplastic transformation and tumor progression. Therefore, kinases are required to be regulated via different genetic and epigenetic processes. MicroRNAs (miRNAs) are among the critical factors involved in epigenetic regulation of protein kinases. Since miRNAs are noninvasive and more stable factors in serum and tissues compared with mRNAs, they can be used as efficient diagnostic markers for the early detection of PCa and BCa.

Main body

In present review, we have summarized all of the reported miRNAs that have been associated with regulation of protein kinases in bladder and prostate cancers.

Conclusions

For the first time, this review highlights the miRNAs as critical factors in regulation of protein kinases during prostate and bladder cancers which paves the way of introducing a noninvasive kinase-specific panel of miRNAs for the early detection of these malignancies. It was observed that the class VIII receptors of tyrosine kinases and non-receptor tyrosine kinases were the most frequent targets for the miRNAs in bladder and prostate cancers, respectively.

Clinical value of microRNA-135a and MMP-13 in colon cancer

The aim of the present study was to investigate the expression and prognostic value of microRNA-135a (miR-135a) and matrix metalloproteinase-13 (MMP-13) in serum of colon cancer (CC). A total of 117 cases of patients admitted to Sheng Li Oil Field Central Hospital from May 2015 to May 2017 were enrolled in the research group (RG), and 120 cases of subjects undergoing normal health examination were included in the control group (CG). The expression of miR-135 and MMP-13 in peripheral blood of the two groups were compared, and their values were analyzed. It was found that miR-135a was decreased and MMP-13 was increased in the RG (P<0.050), both of which were closely related to the pathological features and prognosis of CC (P<0.050), and was also significantly correlated with CEA (P<0.001). ROC curve analysis showed that both of them had great predictive value for the occurrence, prognosis and death of CC. In conclusion, miR-135a was low expressed in CC, while MMP-13 was increased in CC, suggesting that the combined detection of the two had a good diagnostic effect on the occurrence of CC, and was closely related to the prognosis of CCC patients, which might be an excellent potential indicator for the diagnosis and treatment of CC in the future.

miR‑135a‑5p inhibits tumor invasion by targeting ANGPT2 in gallbladder cancer

Gallbladder cancer (GBC) is the most aggressive cancer type in the biliary tract, and our previous studies observed that microRNA (miR)-135a-5p expression was downregulated in GBC tissues. However, few studies have focused on the mechanism of action of the miR-135a-5p target genes in GBC. The present study aimed to investigate the regulatory role of miR-135a-5p signaling in GBC. The present study found that miR-135a-5p expression was downregulated in GBC tissue, as detected by immunohistochemistry and reverse transcription-quantitative PCR. In addition, overexpression of miR-135a-5p significantly inhibited the proliferation and migration of GBC-SD cells. Using a luciferase activity assay, it was identified that angiopoietin-2 (ANGPT2) was a potential target gene of miR-135a-5p in GBC. Knockdown of ANGPT2 expression significantly inhibited the proliferation and invasion of GBC-SD cells. In conclusion, the present results suggested that miR-135a-5p affected GBC cell proliferation and invasion by targeting ANGPT2. Moreover, miR-135a-5p may be a potential biomarker for GBC progression and a potential target for GBC therapeutic intervention.

Abnormal expression of miR-135a in patients with depression and its possible involvement in the pathogenesis of the condition

At present, due to the increasing pressures on society and the stress of everyday living, the number of individuals suffering from depression has increased. Therefore, the treatment of depression has also received increasing attention. MicroRNA (miRNA/miR)-135a is a well-studied miRNA. It has been reported that miR-135a is significantly downregulated in patients with depression and may be a potential marker for the diagnosis of the condition. However, the specific mechanisms of action of miR-135a in patients with depression remain unclear. In the present study, it was found that miR-135a was downregulated in patients with depression, and in a mouse model of depression. The effects of miR-135a on depression-related symptoms in mice were then explored. In the mice with chronic unpredictable mild stress (CUMS) that were treated with miR-135a for 3 weeks, a significantly reduced level of weight gain was observed in comparison with the control group. In addition, treatment with miR-135a mimic significantly increased sucrose preference in the sucrose preference test in the mice, and reduced the immobility time in the forced swimming test and tail suspension test. Treatment with miR-135a mimic also inhibited CUMS-induced hippocampal cell apoptosis. Furthermore, treatment with miR-135a mimic and fluoxetine significantly reduced the CUMS-induced increase in the expression levels of inflammatory factors (IL-1β, IL-6 and TNF-α) in the hippocampus of the mice. Subsequently, reverse transcription-quantitative polymerase chain reaction and western blot analysis revealed that treatment with miR-135a mimic significantly inhibited the expression of Toll-like receptor 4 in the mouse hippocampus. In conclusion, the findings of the present study indicate that miR-135a may be a novel potential target for the treatment of depression.

miR-135a Reduces Osteosarcoma Pulmonary Metastasis by Targeting Both BMI1 and KLF4

Because of the modest response rate after surgery and chemotherapy, treatment of osteosarcoma (OS) remains challenging due to tumor recurrence and metastasis. miR-135a has been reported to act as an anticarcinogenic regulator of several cancers. However, its expression and function in osteosarcoma remain largely unknown. Here, we reported that abridged miR-135a expression in OS cells and tissues, and its expression is inversely correlated with the expression of BMI1 and KLF4, which are described as oncogenes in several cancers. Ectopic expression of miR-135a inhibited cell invasion and expression of BMI1 and KLF4 in OS cells. In vivo investigation confirmed that miR-135a acts as a tumor suppressor in OS to inhibit tumor growth and lung metastasis in xenograft nude mice. BMI1 and KLF4 were revealed to be direct targets of miR-135a, and miR-135a had a similar effect as the combination of si-BMI1 and si-KLF4 on inhibiting tumor progression and the expression of BMI1 and KLF4 in vivo. Altogether, our results demonstrate that the targeting of BMI1/KLF4 with miR-135a may provide an applicable strategy for exploring novel therapeutic approaches for OS.

Prostate Carcinogenesis: Insights in Relation to Epigenetics and Inflammation

Prostate cancer is a multifactorial disease that mainly occurs due to the accumulation of somatic, genetic, and epigenetic changes, resulting in the inactivation of tumor-suppressor genes and activation of oncogenes. Mutations in genes, specifically those that control cell growth and division or the repair of damaged DNA, make the cells grow and divide uncontrollably to form a tumor. The risk of developing prostate cancer depends upon the gene that has undergone the mutation. Identifying such genetic risk factors for prostate cancer poses a challenge for the researchers. Besides genetic mutations, many epigenetic alterations, including DNA methylation, histone modifications (methylation, acetylation, ubiquitylation, sumoylation, and phosphorylation) nucleosomal remodeling, and chromosomal looping, have significantly contributed to the onset of prostate cancer as well as the prognosis, diagnosis, and treatment of prostate cancer. Chronic inflammation also plays a major role in the onset and progression of human cancer, via modifications in the tumor microenvironment by initiating epithelialmesenchymal transition and remodeling the extracellular matrix. In this article, the authors present a brief history of the mechanisms and potential links between the genetic aberrations, epigenetic changes, inflammation, and inflammasomes that are known to contribute to the prognosis of prostate cancer. Furthermore, the authors examine and discuss the clinical potential of prostate carcinogenesis in relation to epigenetics and inflammation for its diagnosis and treatment..

Cell-free nucleic acid patterns in disease prediction and monitoring-hype or hope?

Interest in the use of cell-free nucleic acids (CFNAs) as clinical non-invasive biomarker panels for prediction and prevention of multiple diseases has greatly increased over the last decade. Indeed, circulating CFNAs are attributable to many physiological and pathological processes such as imbalanced stress conditions, physical activities, extensive apoptosis of different origin, systemic hypoxic-ischemic events and tumour progression, amongst others. This article highlights the involvement of circulating CFNAs in local and systemic processes dealing with the question, whether specific patterns of CFNAs in blood, their detection, quantity and quality (such as their methylation status) might be instrumental to predict a disease development/progression and could be further utilised for accompanying diagnostics, targeted prevention, creation of individualised therapy algorithms, therapy monitoring and prognosis. Presented considerations conform with principles of 3P medicine and serve for improving individual outcomes and cost efficacy of medical services provided to the population.

MicroRNA-135a Protects Against Ethanol-Induced Apoptosis in Neural Crest Cells and Craniofacial Defects in Zebrafish by Modulating the Siah1/p38/p53 Pathway

MicroRNAs (miRNAs) are small non-coding RNAs that are involved in various biological processes, including apoptosis, by regulating gene expression. This study was designed to test the hypothesis that ethanol-induced downregulation of miR-135a contributes to ethanol-induced apoptosis in neural crest cells (NCCs) by upregulating Siah1 and activating the p38 mitogen-activated protein kinase (MAPK)/p53 pathway. We found that treatment with ethanol resulted in a significant decrease in miR-135a expression in both NCCs and zebrafish embryos. Ethanol-induced downregulation of miR-135a resulted in the upregulation of Siah1 and the activation of the p38 MAPK/p53 pathway and increased apoptosis in NCCs and zebrafish embryos. Ethanol exposure also resulted in growth retardation and developmental defects that are characteristic of fetal alcohol spectrum disorders (FASD) in zebrafish. Overexpression of miRNA-135a significantly reduced ethanol-induced upregulation of Siah1 and the activation of the p38 MAPK/p53 pathway and decreased ethanol-induced apoptosis in NCCs and zebrafish embryos. In addition, ethanol-induced growth retardation and craniofacial defects in zebrafish larvae were dramatically diminished by the microinjection of miRNA-135a mimics. These results demonstrated that ethanol-induced downregulation of miR-135a contributes to ethanol-induced apoptosis in NCCs by upregulating Siah1 and activating the p38 MAPK/p53 pathway and that the overexpression of miRNA-135a can protect against ethanol-induced apoptosis in NCCs and craniofacial defects in a zebrafish model of FASD.

Role of microRNAs in the development, prognosis and therapeutic response of patients with prostate cancer

Prostate cancer is the most common cancer in males in several regions. One of the major challenges in diagnosis and treatment of this cancer is how to identify men who harbor an increased risk of having clinically significant prostate cancer and how to assess response to therapy. Biomarkers, like microRNAs (miRNAs) are one of the new diagnostic/therapeutic tools for clinicians. Finding men at high risk of significant cancer is essential as they will mostly benefit from earlier diagnosis and treatment. At the same time, it is important to reduce the number of unnecessary invasive biopsies in men without (clinically significant) cancer and miRNAs have especial application in this regard. MiRNAs can regulate expression of several genes. Up to 30 percent of protein coding genes are regulated by miRNAs. Based on this critical regulatory role, miRNAs impact cell differentiation, growth and apoptosis. Several studies have reported aberrant expression of miRNAs in different cancers including prostate cancer. miRNAs are regarded as biomarkers in this kind of cancer. Moreover, expression profiles of miRNAs can predict therapeutic response to a number of drugs such docetaxel and some natural agents such as isoflavone. Functional studies have shown that miRNAs regulate a number of critical targets such as Wnt/β-catenin, PI3K/AKT, cyclin dependent kinases, VEGF and JAK/ STAT. Therefore, several aspects of prostate cancer development are influenced by miRNAs. Finally, circulating miRNAs are promising tools for assessment of prostate cancer course and prognosis. In the current review, we summarize the results of studies which reported abnormal expression of miRNAs in prostate cancer and their role as biomarkers or therapeutic targets.

MiR-135a biogenesis and regulation in malignancy: a new hope for cancer research and therapy

MicroRNAs (miRNAs) are evolutionarily conserved small non-coding RNAs that affect posttranscriptional regulation by binding to the 3′-untranslated region of target messenger RNAs. MiR-135a is a critical miRNA that regulates gene expression, and many studies have focused on its function in cancer research. MiR-135a is dysregulated in various cancers and regulates cancer cell proliferation and invasion via several signaling pathways, such as the MAPK and JAK2/STAT3 pathways. MiR-135a has also been found to promote or inhibit the epithelial-mesenchymal transition and chemoresistance in different cancers. Several studies have discovered the value of miR-135a as a novel biomarker for cancer diagnosis and prognosis. These studies have suggested the potential of therapeutically manipulating miR-135a to improve the outcome of cancer patients. Although these findings have demonstrated the role of miR-135a in cancer progression and clinical applications, a number of questions remain to be answered, such as the dual functional roles of miR-135a in cancer. In this review, we summarize the available studies regarding miR-135a and cancer, including background on the biogenesis and expression of miR-135a in cancer and relevant signaling pathways involved in miR-135a-mediated tumor progression. We also focus on the clinical application of miR-135a as a biomarker in diagnosis and as a therapeutic agent or target in cancer treatment, which will provide a greater level of insight into the translational value of miR-135a.

Potential Five-MicroRNA Signature Model for the Prediction of Prognosis in Patients with Wilms Tumor

Background

Wilms tumor (WT) is the most common type of pediatric renal malignancy, and is associated with poor prognosis. The aim of the present study was to identify microRNA (miRNA) signatures which might predict prognosis and categorize WTs into high- and low-risk subgroups.

Material/Methods

The miRNA expression profiles of WT patients and normal samples were obtained from the Therapeutically Applicable Research to Generate Effective Treatment database. Differentially expressed miRNAs between WT patients and normal samples were identified using the EdgeR package. Subsequently, correlations between differentially expressed miRNAs and the prognosis of overall survival were analyzed. Enrichment analyses for the targeted mRNAs were conducted via the Database for Annotation, Visualization, and Integration Discovery.

Results

A total of 154 miRNAs were identified as differentially expressed in WT. Of those, 18 miRNAs were associated with overall survival (P<0.05). A prognostic signature of 5 differentially expressed miRNAs (i.e., has-mir-149, has-mir-7112, has-mir-940, has-mir-1248, and has-mir-490) was constructed to classify the patients into high- and low-risk subgroups. The targeted mRNAs of these prognostic miRNAs were primarily enriched in Gene Ontology terms (i.e., protein autophosphorylation, protein dephosphorylation, and stress-activated MAPK cascade) and the Kyoto Encyclopedia of Genes and Genomes signaling pathways (i.e., MAPK, AMPK, and PI3K-Akt).

Conclusions

The 5-miRNA signature model might be useful in determining the prognosis of WT patients. As a promising prediction tool, this prognosis signature might serve as a potential biomarker for WT patients.

MiR-135a-5p Is Critical for Exercise-Induced Adult Neurogenesis

Physical exercise stimulates adult hippocampal neurogenesis and is considered a relevant strategy for preventing age-related cognitive decline in humans. The underlying mechanisms remains controversial. Here, we show that exercise increases proliferation of neural precursor cells (NPCs) of the mouse dentate gyrus (DG) via downregulation of microRNA 135a-5p (miR-135a). MiR-135a inhibition stimulates NPC proliferation leading to increased neurogenesis, but not astrogliogenesis, in DG of resting mice, and intriguingly it re-activates NPC proliferation in aged mice. We identify 17 proteins (11 putative targets) modulated by miR-135 in NPCs. Of note, inositol 1,4,5-trisphosphate (IP3) receptor 1 and inositol polyphosphate-4-phosphatase type I are among the modulated proteins, suggesting that IP3 signaling may act downstream miR-135. miR-135 is the first noncoding RNA essential modulator of the brain's response to physical exercise. Prospectively, the miR-135-IP3 axis might represent a novel target of therapeutic intervention to prevent pathological brain aging.

Sulforaphane Induces miR135b-5p and Its Target Gene, RASAL2, thereby Inhibiting the Progression of Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDA) is one of the most lethal tumors, with poor therapeutic options in the advanced state. The broccoli-derived anti-inflammatory agent sulforaphane was shown to inhibit the progression of pancreatic cancer and other tumor entities. We examined the involvement of pancreatic cancer cell lines were evaluated by microRNA and gene expression arrays, bioinformatics, in silico analysis, qRT-PCR, western blotting, immunohistochemistry, in situ hybridization, self-renewal and differentiation assays, and in vivo xenograft studies. We selected the top nine differentially expressed microRNAs, and miR135b-5p was chosen as the most important candidate for the sulforaphane-induced upregulation of the tumor suppressor gene RASAL2. The expression of miR135b-5p and RASAL2 was almost absent in malignant pancreatic tissues and cell lines, but not in their normal counterparts. Lipofection of miR135b-5p enhanced RASAL2 expression and inhibited ERK1/2 signaling, viability, self-renewal capacity, and tumor growth. These results indicate that miR135b-5p acts as a tumor suppressor via the induction of RASAL2 in PDA.

miR-135 regulated breast cancer proliferation and epithelial-mesenchymal transition acts by the Wnt/β-catenin signaling pathway

Breast cancer (BC) is the most common cancer in women around the world. microRNAs (miRNAs/miRs) have been proved to be associated with the development and progression of breast cancer. In the present study, to elucidate the effects of dysregulated miR‑135 on cells and underlying mechanisms in BC, in vitro and in vivo experiments were conducted. The biological functions of miR‑135 were studied using MTT, colony formation, wound healing, transwell assays as well as tumorigenicity analysis. Gain‑ and loss‑ of function of miR‑135 studies revealed that ectopic expression of miR‑135 in MDA‑MB‑468 and MCF‑7 cells significantly inhibited cell growth, migration, invasion and EMT, at least in part through inhibiting the activation of the Wnt/β‑catenin pathway. Moreover, this was reversed in cells which were transfected with miR‑135 inhibitors. Taken together, the results of the present study provided evidence that miR‑135 acted as a tumor suppressor in BC, which may represent a novel therapeutic strategy for the diagnosis and prognosis of BC.

Biomarker microRNAs for prostate cancer metastasis: screened with a network vulnerability analysis model

Background

Prostate cancer (PCa) is a fatal malignant tumor among males in the world and the metastasis is a leading cause for PCa death. Biomarkers are therefore urgently needed to detect PCa metastatic signature at the early time. MicroRNAs are small non-coding RNAs with the potential to be biomarkers for disease prediction. In addition, computer-aided biomarker discovery is now becoming an attractive paradigm for precision diagnosis and prognosis of complex diseases.

Methods

In this study, we identified key microRNAs as biomarkers for predicting PCa metastasis based on network vulnerability analysis. We first extracted microRNAs and mRNAs that were differentially expressed between primary PCa and metastatic PCa (MPCa) samples. Then we constructed the MPCa-specific microRNA-mRNA network and screened microRNA biomarkers by a novel bioinformatics model. The model emphasized the characterization of systems stability changes and the network vulnerability with three measurements, i.e. the structurally single-line regulation, the functional importance of microRNA targets and the percentage of transcription factor genes in microRNA unique targets.

Results

With this model, we identified five microRNAs as putative biomarkers for PCa metastasis. Among them, miR-101-3p and miR-145-5p have been previously reported as biomarkers for PCa metastasis and the remaining three, i.e. miR-204-5p, miR-198 and miR-152, were screened as novel biomarkers for PCa metastasis. The results were further confirmed by the assessment of their predictive power and biological function analysis.

Conclusions

Five microRNAs were identified as candidate biomarkers for predicting PCa metastasis based on our network vulnerability analysis model. The prediction performance, literature exploration and functional enrichment analysis convinced our findings. This novel bioinformatics model could be applied to biomarker discovery for other complex diseases.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1506-7) contains supplementary material, which is available to authorized users.

Micrornas in prostate cancer: an overview

Prostate cancer is the second highest cause of cancer mortality after lung tumours. In USA it affects about 2.8 million men and the incidence increases with age in many countries. Therefore, early diagnosis is a very important step for patient clinical evaluation and for a selective and efficient therapy. The study of miRNAs' functions and molecular mechanisms has brought new knowledge in biological processes of cancer. In prostate cancer there is a deregulation of several miRNAs that may function as tumour suppressors or oncogenes. The aim of this review is to analyze the progress made to our understanding of the role of miRNA dysregulation in prostate cancer tumourigenesis.

Epidermal growth factor receptor (EGFR): A rising star in the era of precision medicine of lung cancer

Lung cancer is a leading cause of cancer mortality worldwide. In tumors, the important role of noncoding RNA regulatory networks has been more and more reveal. EGFR has been identified as an oncogenic driver of NSCLC, especially activating mutations EGFR and its inhibition with specific TKIs can generate dramatic tumor responses. Studies have shown that EGFR plays significant roles in the progression of NSCLC. Subset analysis of the small proportion of patients with EGFR-mutant lung cancer showed a disease-free survival benefit, but was underpowered to detect a survival advantage. Herein, we highlight the progression of EGFR, noncoding RNA, and their roles in carcinogenesis. We also focus on anti-lung cancer drug development and EGFR-related drug resistance.

MicroRNA-155 inhibits the osteogenic differentiation of mesenchymal stem cells induced by BMP9 via downregulation of BMP signaling pathway

Previous studies have indicated that bone morphogenetic protein 9 (BMP9) can promote the osteogenic differentiation of mesenchymal stem cells (MSCs) and increase bone formation in bone diseases. However, the mechanisms involved remained poorly understood. It is necessary to investigate the specific regulatory mechanisms of osteogenic differentiation that were induced by BMP9. During the process of osteogenic differentiation induced by BMP9, the expression of microRNA-155 (miR-155) exhibited a tendency of increasing at first and then decreasing, which made us consider that miR-155 may have a modulatory role in this process, but the roles of this process have not been elucidated. This study aimed to uncover miR-155 capable of concomitant regulation of this process. mmu-miR-155 mimic (miR-155) was transfected into MSCs and osteogenesis was induction by using recombinant adenovirus expressing BMP9. Overexpressed miR-155 in MSCs led to a decrease in alkaline phosphatase (ALP) staining and Alizarin red S staining during osteogenic differentiation, and reduced the expression of osteogenesis-related genes, such as runt-related transcription factor 2 (Runx2), osterix (OSX), osteocalcin (OCN) and osteopontin (OPN). On protein levels, overexpressed miR-155 markedly decreased the expression of phosphorylated Smad1/5/8 (p-Smad1/5/8), Runx2, OCN and OPN. Luciferase reporter assay revealed Runx2 and bone morphogenetic protein receptor 9 (BMPR2) are two direct target genes of miR-155. Downregulation of the expression of Runx2 and BMPR2, respectively could offset the inhibitory effect of miR-155 in the osteogenesis of MSCs. In vivo, subcutaneous ectopic osteogenesis of MSCs in nude mice showed miR-155 inhibited osteogenic differentiation. In conclusion, our results demonstrated that miR-155 can inhibit the osteogenic differentiation induced by BMP9 in MSCs.

miR-539 acts as a tumor suppressor by targeting epidermal growth factor receptor in breast cancer

Breast cancer is the most frequently diagnosed malignancy and the leading cause of cancer-associated death in women worldwide. microRNAs (miRNAs) play critical roles in the cellular processes of breast cancer. However, the crucial roles and underlying mechanisms of miR-539 in breast cancer remain unclear. By RT-qPCR, we found that expression of miR-539 was markedly down-regulated in breast cancer tissues and cell lines compared with that in paired adjacent normal tissues and normal cell lines. The low level of miR-539 expression was positively associated with lymph node metastasis. Furthermore, forced expression of miR-539 inhibited proliferation and migration of breast cancer MDA-MB-231 and MCF7 cells in vitro and suppressed tumor growth in vivo. Moreover, bioinformatics analysis and luciferase reporter assays indicated that epidermal growth factor receptor (EGFR) was a direct target of miR-539. Over-expression of miR-539 decreased the EGFR mRNA and protein levels in MDA-MB-231 and MCF7 cells. In addition, ectopic over-expression of EGFR partly reversed miR-539-inhibited proliferation as well as migration of MDA-MB-231 and MCF7 cells. Taken together, our results demonstrate that miR-539 functions as a tumor suppressor in breast cancer by downregulating EGFR, supporting the targeting of the novel miR-539/EGFR axis as a potentially effective therapeutic approach for breast cancer.

MicroRNA-135a regulates NHE9 to inhibit proliferation and migration of glioblastoma cells

Background

Glioblastoma multiformae (GBM) is the most aggressive type of malignant brain tumor with complex molecular profile. Overexpression of Na⁺/H⁺ Exchanger isoform 9 (NHE9) promotes tumor progression and correlates positively with insensitivity to radiochemotherapy and poor prognosis. However, molecular mechanisms responsible for increase in NHE9 levels beyond a critical threshold have not been identified.

Methods

Bioinformatics analysis, luciferase reporter assays, real-time PCR and western blotting were conducted to examine the expression profiles and identify microRNAs (miRNA) that target NHE9. Cell proliferation and migration assays were conducted in U87 glioblastoma cells to determine the consequence of miRNA mediated targeting of NHE9. Endosomal pH measurements, immunofluorescence microscopy and surface biotinylation experiments were conducted to characterize the mechanistic basis of regulation.

Results

We show that microRNA 135a (miR-135a) targets NHE9 to downregulate its expression in U87 cells. MiR-135a levels are significantly lower in glioblastoma cells compared to normal brain tissue. Downregulation of NHE9 expression by miR-135a affects proliferative and migratory capacity of U87 cells. Selectively increasing NHE9 expression in these cells restored their ability to proliferate and migrate. We demonstrate that miR-135a takes a two-pronged approach affecting epidermal growth factor receptors (EGFRs) to suppress tumor cell growth and migration. EGFR activity is a potent stimulator of oncogenic signaling. While miR-135a targets EGFR transcripts to decrease the total number of receptors made, by targeting NHE9 it routes the few EGFRs made away from the plasma membrane to dampen oncogenic signaling. NHE9 is localized to sorting endosomes in glioblastoma cells where it alkalinizes the endosome lumen by leaking protons. Downregulation of NHE9 expression by miR-135a acidifies sorting endosomes limiting EGFR trafficking to the glioblastoma cell membrane.

Conclusions

We propose downregulation of miR-135a as a potential mechanism underlying the high NHE9 expression observed in subset of glioblastomas. Future studies should explore miR-135a as a potential therapeutic for glioblastomas with NHE9 overexpression.

Electronic supplementary material

The online version of this article (10.1186/s12964-017-0209-7) contains supplementary material, which is available to authorized users.

Involvement of aberrantly activated HOTAIR/EZH2/miR-193a feedback loop in progression of prostate cancer

Background

Though androgen deprivation therapy is the standard treatment for prostate cancer (PCa), most patients would inevitably progress to castration-resistant prostate cancer (CRPC) which is the main cause of PCa death. Therefore, the identification of novel molecular mechanism regulating cancer progression and achievement of new insight into target therapy would be necessary for improving the benefits of PCa patients. This study aims to study the function and regulatory mechanism of HOTAIR/EZH2/miR-193a feedback loop in PCa progression.

Methods

MSKCC and TCGA datasets were used to identify miR-193a expression profile in PCa. Cell Counting Kit-8 (CCK-8) assays, colony formation, invasion, migration, flow cytometry, a xenograft model and Gene Set Enrichment Analysis were used to detect and analyze the biological function of miR-193a. Then, we assessed the role of HOTAIR and EZH2 in regulation of miR-193a expression by using plasmid, lentivirus and small interfering RNA (siRNA). Luciferase reporter assays and chromatin immunoprecipitation assays were performed to detect the transcriptional activation of miR-193a by EZH2 and HOTAIR. Further, qRT-PCR and luciferase reporter assays were conducted to examine the regulatory role of miR-193a controlling the HOTAIR expression in PCa. Finally, the correlation between HOTAIR, EZH2 and miR-193a expression were analyzed using In situ hybridization and immunohistochemistry.

Results

We found that miR-193a was significantly downregulated in metastatic PCa through mining MSKCC and TCGA datasets. In vitro studies revealed that miR-193a inhibited PCa cell growth, suppressed migration and invasion, and promoted apoptosis; in vivo results demonstrated that overexpression of miR-193a mediated by lentivirus dramatically reduced PCa xenograft tumor growth. Importantly, we found EZH2 coupled with HOTAIR to repress miR-193a expression through trimethylation of H3K27 at miR-193a promoter in PC3 and DU145 cells. Interestingly, further evidence illustrated that miR-193a directly targets HOTAIR showing as significantly reduced HOTAIR level in miR-193a overexpressed cells and tissues. The expression level of miR-193a was inversely associated with that of HOTAIR and EZH2 in PCa.

Conclusion

This study firstly demonstrated that miR-193a acted as tumor suppressor in CRPC and the autoregulatory feedback loop of HOTAIR/EZH2/miR-193a served an important mechanism in PCa development. Targeting this aberrantly activated feedback loop may provide a potential therapeutic strategy.

Electronic supplementary material

The online version of this article (doi: 10.1186/s13046-017-0629-7) contains supplementary material, which is available to authorized users.

MicroRNA-30a functions as tumor suppressor and inhibits the proliferation and invasion of prostate cancer cells by down-regulation of SIX1

Increasing reports have demonstrated that aberrant expression of microRNAs (miRNAs) is found in multiple human cancers. Many studies have shown that down-regulated level of miR-30a is in a variety of cancers including prostate cancer (PCa). However, the precise mechanisms of miR-30a in PCa have not been well explored. In this study, we investigated the biological functions and molecular mechanism of miR-30a in PCa cell lines, discussing whether it could be a therapeutic biomarker of PCa in the future. We found that miR-30a is down-regulated in PCa tissues and cell lines. Moreover, the low level of miR-30a was associated with increased expression of SIX1 in PCa tissues and cell lines. Up-regulation of miR-30a significantly inhibited proliferation of PCa cells. In addition, invasion of PCa cells was suppressed by overexpression of miR-30a. However, down-regulation of miR-30a promoted cell growth and invasion of PCa cells. Bioinformatics analysis predicted that the SIX1 was a potential target gene of miR-30a. Next, luciferase reporter assay confirmed that miR-30a could directly target SIX1. Consistent with the effect of miR-30a, down-regulation of SIX1 by siRNA inhibited proliferation and invasion of PCa cells. Overexpression of SIX1 in PCa cells partially reversed the effect of miR-30a mimic. In conclusion, introduction of miR-30a dramatically inhibited proliferation and invasion of PCa cells by down-regulating SIX1 expression, and that down-regulation of SIX1 was essential for inhibition of cell growth and invasion of PCa cells by overexpression of miR-30a.

Dicer suppresses cytoskeleton remodeling and tumorigenesis of colorectal epithelium by miR-324-5p mediated suppression of HMGXB3 and WASF-2

Emerging evidence indicates that microRNAs, a class of small and well-conserved noncoding RNAs, participate in many physiological and pathological processes. RNase III endonuclease DICER is one of the key enzymes for microRNA biogenesis. Here, we found that DICER was downregulated in tumor samples of colorectal cancer (CRC) patients at both mRNA and protein levels. Importantly, intestinal epithelial cell (IEC)-specific deletion of Dicer mice got more tumors after azoxymethane and dextran sulfate sodium (DSS) administration. Interestingly, IEC-specific deletion of Dicer led to severe chronic inflammation and epithelium layer remodeling in mice with or without DSS administration. Microarray analysis of 3 paired Dicer deletion CRC cell lines showed that miR-324-5p was one of the most significantly decreased miRNAs. In the intestinal epithelium of IEC-specific deletion of Dicer mice, miR-324-5p was also found to be markedly reduced. Mechanistically, miR-324-5p directly bound to the 3′untranslated regions (3′UTRs) of HMG-box containing 3 (HMGXB3) and WAS protein family member 2 (WASF-2), two key proteins participated in cell motility and cytoskeleton remodeling, to suppress their expressions. Intraperitoneal injection of miR-324-5p AgomiR (an agonist of miR-324-5p) curtailed chronic inflammation and cytoskeleton remodeling of colorectal epithelium and restored intestinal barrier function in IEC-specific deletion of Dicer mice induced by DSS. Therefore, our study reveals a key role of a DICER/miR-324-5p/HMGXB3/WASF-2 axis in tumorigenesis of CRC by regulation of cytoskeleton remodeling and maintaining integrity of intestinal barriers.