MicroRNAs in tumorigenesis: a primer

Review of microRNA detection workflows from liquid biopsy for disease diagnostics

MicroRNAs have emerged as effective biomarkers in disease diagnostics, particularly cancer, due to their role as regulatory sequences. More recently, microRNAs have been detected in liquid biopsies, which hold immense potential for early disease diagnostics. This review comprehensively analyses distinct liquid biopsy microRNA detection methods validated with clinical samples. Each step in the microRNA detection workflow, including sample collection, RNA isolation, processing, and detection of target microRNAs, has been thoroughly assessed. The review discusses the advantages and limitations of established and novel techniques in microRNA detection workflows, discussing their diagnostic capabilities and potential for future implementation at scale.

MDbDMRP: A novel molecular descriptor-based computational model to identify drug-miRNA relationships

MicroRNAs (miRNAs) are important in gene expression regulation and many other biological processes and have emerged as promising therapeutic targets. Identifying potential drug-miRNA relationships is helpful in disease therapy and pharmaceutical engineering in medical research. However, accurately predicting these relationships remains a significant computational challenge. This study introduces MDbDMRP, a novel molecular descriptors-based drug-miRNA relationship prediction computational model designed to address this challenge. MDbDMRP leverages the power of machine learning to predict new drug-miRNA associations and non-associations. The model achieves exceptional performance, exceeding an average score of 0.92 across various evaluation metrics, including accuracy, precision, recall, and F1-score. Furthermore, it demonstrates a remarkable ability to distinguish between positive and negative interactions, as evidenced by an outstanding AUC-ROC score of 0.9864. The results obtained from MDbDMRP were further validated through molecular docking, reinforcing its performance. These results position MDbDMRP as a valuable tool for researchers aiming to unlock the potential of miRNAs in drug discovery.

ATP-Binding Cassette Transporter Genes and microRNAs in Pediatric B-Cell ALL: Expression Insights

BACKGROUND

Acute lymphocytic leukemia (ALL), characterized by uncontrolled growth of abnormal lymphocytes, predominantly affects children. Genetic analysis focusing on genes and microRNAs reveals important information about the biology of ALL, enabling accurate diagnosis and treatment. This study examines gene and microRNA expression in B cell ALL to improve early diagnosis and personalized treatment.

METHODS

Bone marrow samples were collected from patients both before and after the induction phase of chemotherapy. Comprehensive diagnostic techniques including flow cytometry, molecular assays, real-time PCR for common translocations, karyotyping, and complete blood count (CBC) analysis were employed. These methods were utilized to determine the type and risk assessment of ALL, identify specific gene and microRNA expressions, and measure blood cell counts.

RESULTS

The study comprised 12 patients, all under the age of 18. Post-treatment RT-PCR analysis revealed significant reductions in the expression of the ABCB1 gene, miR-129-5p, and miR-9-5p following the induction phase of chemotherapy. Karyotype analysis indicated that two patients were hypodiploid; unfortunately, both of these patients did not survive.

CONCLUSION

MicroRNAs and ABC genes serve as predictive and prognostic biomarkers in Acute Lymphoblastic Leukemia (ALL) and should be carefully reconsidered. It is more accurate to state that while microRNAs and ABC genes may potentially influence treatment response in ALL, further research is crucial to fully understand their roles in determining treatment outcomes.

High Expression of miR-218-5p in the Peripheral Blood Stream and Tumor Tissues of Pediatric Patients with Sarcomas

Sarcomas are malignant tumors that may metastasize and the course of the disease is highly aggressive in children and young adults. Because of the rare incidence of sarcomas and the heterogeneity of tumors, there is a need for non-invasive diagnostic and prognostic biomarkers in sarcomas. The aim of the study was to investigate the level of miR-218-5p in peripheral blood and tumor tissue samples of Ewing's sarcoma, osteosarcoma, spindle cell sarcoma patients, and healthy controls, and assessed whether the corresponding molecule was a diagnostic and prognostic biomarker. The study was performed patients (n = 22) diagnosed and treated with Ewing's sarcoma and osteosarcoma and in a control group of 22 healthy children who were matched for age, gender, and ethnicity with the patient group. The expression level of miR-218-5p in RNA samples from peripheral blood and tissue samples were analyzed using the RT-PCR and the expression level of miR-218-5p was evaluated by comparison with the levels in patients and healthy controls. The expression level of miR-218-5p was found to be statistically higher (3.33-fold, p = 0.006) in pediatric patients with sarcomas and when the target genes of miR-218-5p were investigated using the bioinformatics tools, the miR-218-5p was found as an important miRNA in cancer. In this study, the miR-218-5p was shown for the first time to have been highly expressed in the peripheral blood and tumor tissue of sarcoma patients. The results suggest that miR-218-5p can be used as a diagnostic and prognostic biomarker in sarcomas and will be evaluated as an important therapeutic target.

Appendiceal Neuroendocrine Neoplasms: A Comprehensive Review

ABSTRACT

Appendiceal neuroendocrine neoplasm (NEN) is the most common adult appendiceal malignant tumor, constituting 16% of gastrointestinal NENs. They are versatile tumors with varying morphology, immunohistochemistry, secretory properties, and cancer genomics. They are slow growing and clinically silent, to begin with, or present with features of nonspecific vague abdominal pain. Most acute presentations are attributed clinically to appendicitis, with most cases detected incidentally on pathology after an appendectomy. Approximately 40% of them present clinically with features of hormonal excess, which is likened to the functional secretory nature of their parent cell of origin. The symptoms of carcinoid syndrome render their presence clinically evident. However, slow growing and symptomatically silent in its initial stages, high-grade neuroendocrine tumors and neuroendocrine carcinomas of the appendix are aggressive and usually have hepatic and lymph node metastasis at presentation. This review article focuses on imaging characteristics, World Health Organization histopathological classification and grading, American Joint Committee on Cancer/Union or International Cancer Control, European Neuroendocrine Tumor Society staging, European Neuroendocrine Tumor Society standardized guidelines for reporting, data interpretation, early-stage management protocols, and advanced-stage appendiceal NENs. Guidelines are also set for the follow-up and reassessment. The role of targeted radiotherapy, chemotherapy, and high-dose somatostatin analogs in treating advanced disease are discussed, along with types of ablative therapies and liver transplantation for tumor recurrence. The search for newer location-specific biomarkers in NEN is also summarized. Regarding the varying aggressiveness of the tumor, there is a scope for research in the field, with plenty of data yet to be discovered.

MicroRNA Landscape in Endometrial Carcinomas in an Asian population: Unraveling Subtype-Specific Signatures

MicroRNAs (MiRNAs) are small, non-coding RNA molecules that function in RNA silencing and post-transcriptional regulation of gene expression. We analyzed the differential expression of miRNAs in 119 endometrial carcinomas, measuring their expression in histological subtypes, molecular subtypes, and tumors with CTNNB1 mutations. Tumors were subdivided into histological and molecular subtypes as defined by The Cancer Genome Atlas. The expression levels of 352 miRNAs were quantified using the PanoramiR panel. Mir-449a, mir-449b-5p, and mir-449c-5p were the top three miRNAs showing increased expression in both endometrioid and de-differentiated carcinomas but were not significantly increased in serous and clear cell carcinomas. The miRNAs with the most increased expression in serous and clear cell carcinomas were miR-9-3p and miR-375, respectively. We also identified 62 differentially expressed miRNAs among different molecular subtypes. Using sequential forward selection, we built subtype classification models for some molecular subtypes of endometrial carcinoma, comprising 5 miRNAs for MMR-deficient tumors, 10 miRNAs for p53-mutated tumors, and 3 miRNAs for CTNNB1-mutated tumors, with areas under curves of 0.75, 0.85, and 0.78, respectively. Our findings confirm the differential expression of miRNAs between various endometrial carcinoma subtypes and may have implications for the development of diagnostic and prognostic tools.

The cryptic role of CXCL17/CXCR8 axis in the pathogenesis of cancers: a review of the latest evidence

Chemokines are immune system mediators that mediate various activities and play a role in the pathogenesis of several cancers. Among these chemokines, C-X-C motif chemokine 17 (CXCL-17) is a relatively novel molecule produced along the airway epithelium in physiological and pathological conditions, and evidence shows that it plays a homeostatic role in most cases. CXCL17 has a protective role in some cancers and a pathological role in others, such as liver and lung cancer. This chemokine, along with its possible receptor termed G protein-coupled receptor 35 (GPR35) or CXCR8, are involved in recruiting myeloid cells, regulating angiogenesis, defending against pathogenic microorganisms, and numerous other mechanisms. Considering the few studies that have been performed on the dual role of CXCL17 in human malignancies, this review has investigated the possible pro-tumor and anti-tumor roles of this chemokine, as well as future treatment options in cancer therapy.

MicroRNA-147b induces neuroendocrine differentiation of prostate cancer cells by targeting ribosomal protein RPS15A

BACKGROUND

Prostate cancer (PCa) is the leading cause of cancer related deaths in men, often androgen deprivation therapy (ADT) leads to the progression of androgen independent PCa (AIPC) which further leads to Neuroendocrine PCa (NEPC). Identifying the molecular mechanisms which navigate the neuroendocrine differentiation (NED) of PCa cells is clinically relevant. It has been suggested that the micro RNAs (miRNAs) play an important role in the regulation of intrinsic mechanisms relevant to tumor progression, resistance as a result leads to poor prognosis. miR-147b has been transpiring as one of the deregulated miRNAs associated with the occurrence of multiple cancers. The present study has studied the role of miRNA-147b in inducing NEPC.

METHODS

To investigate the functional role of miR-147b in NEPC, we have expressed miRNA mimics or inhibitors in PCa cells and monitored the progression of NEPC along with PCa cell proliferation and survival. The molecular mechanism miRNA-147b follows was studied using western blot and reverse transcription polymerase chain analysis. miRNA target prediction using bioinformatics tools followed by target validation using luciferase reporter assays was performed.

RESULTS

In the present study, we found that miR-147b is highly expressed in AIPC cell lines in particular neuroendocrine cells NCI-H660 and NE-LNCaP derived from LNCaP. Mechanistic studies revealed that overexpression of miR-147b or miRNA mimics induced NED in LNCaP cells in in-vitro while its inhibitor reversed the NE features (increased NE markers and reduced prostate specific antigen) of PC3, NCI-H660 and NE-LNCaP cells. In addition, miR-147b reduced the proliferation rate of LNCaP cells via elevated p27kip1 and lowered cyclin D1 for promoting differentiation. In reporter assays, we have identified ribosomal protein S15A (RPS15A) is a direct target of miRNA-147b and RPS15A expression was negatively regulated by miR-147b in PCa cells. Furthermore, we also report that RPS15A is downregulated in NEPC cells and its expression is inversely correlated with NE markers.

CONCLUSION

Targeting the miR-147b - RPS15A axis may overcome the progression of NEPC and serve as a novel therapeutic target to attenuate NED progression of PCa.

Identification and validation of miR-583 and mir-877-5p as biomarkers in patients with breast cancer: an integrated experimental and bioinformatics research

OBJECTIVES

Breast cancer (BC) is one of the most common cancers with a high mortality rate in women worldwide. The advantages of early cancer diagnosis are apparent, and it is a critical factor in increasing the patient's life and survival. According to mounting evidence, microRNAs (miRNAs) may be crucial regulators of critical biological processes. miRNA dysregulation has been linked to the beginning and progression of various human malignancies, including BC, and can operate as tumor suppressors or oncomiRs. This study aimed to identify novel miRNA biomarkers in BC tissues and non-tumor adjacent tissues of patients with BC. Microarray datasets GSE15852 and GSE42568 for differentially expressed genes (DEGs) and GSE45666, GSE57897, and GSE40525 for differentially expressed miRNAs (DEMs) retrieved from the Gene Expression Omnibus (GEO) database were analyzed using "R" software. A protein-protein interaction (PPI) network was created to identify the hub genes. MirNet, miRTarBase, and MirPathDB databases were used to predict DEMs targeted genes. Functional enrichment analysis was used to demonstrate the topmost classifications of molecular pathways. The prognostic capability of selected DEMs was evaluated through a Kaplan-Meier plot. Moreover, the specificity and sensitivity of detected miRNAs to discriminate BC from adjacent controls were assessed by area under the curve (AUC) using the ROC curve analysis. In the last phase of this study, gene expression on 100 BC tissues and 100 healthy adjacent tissues were analyzed and calculated by using the Real-Time PCR method.

RESULTS

This study declared that miR-583 and miR-877-5p were downregulated in tumor samples in comparison to adjacent non-tumor samples (|logFC|< 0 and P ≤ 0.05). Accordingly, ROC curve analysis demonstrated the biomarker potential of miR-877-5p (AUC = 0.63) and miR-583 (AUC = 0.69). Our results showed that has-miR-583 and has-miR-877-5p could be potential biomarkers in BC.

MuCoMiD: A Multitask Graph Convolutional Learning Framework for miRNA-Disease Association Prediction

Growing evidence from recent studies implies that microRNAs or miRNAs could serve as biomarkers in various complex human diseases. Since wet-lab experiments for detecting miRNAs associated with a disease are expensive and time-consuming, machine learning techniques for miRNA-disease association prediction have attracted much attention in recent years. A big challenge in building reliable machine learning models is that of data scarcity. In particular, existing approaches trained on the available small datasets, even when combined with precalculated handcrafted input features, often suffer from bad generalization and data leakage problems. We overcome the limitations of existing works by proposing a novel multitask graph convolution-based approach, which we refer to as MuCoMiD. MuCoMiD allows automatic feature extraction while incorporating knowledge from five heterogeneous biological information sources (associations between miRNAs/diseases and protein-coding genes (PCGs), interactions between protein-coding genes, miRNA family information, and disease ontology) in a multitask setting which is a novel perspective and has not been studied before. To effectively test the generalization capability of our model, we conduct large-scale experiments on the standard benchmark datasets as well as on our proposed large independent testing sets and case studies. MuCoMiD obtains significantly higher Average Precision (AP) scores than all benchmarked models on three large independent testing sets, especially those with many new miRNAs, as well as in the detection of false positives. Thanks to its capability of learning directly from raw input information, MuCoMiD is easier to maintain and update than handcrafted feature-based methods, which would require recomputation of features every time there is a change in the original information sources (e.g., disease ontology, miRNA/disease-PCG associations, etc.). We share our code for reproducibility and future research at https://git.l3s.uni-hannover.de/dong/cmtt.

A message passing framework with multiple data integration for miRNA-disease association prediction

Micro RNA or miRNA is a highly conserved class of non-coding RNA that plays an important role in many diseases. Identifying miRNA-disease associations can pave the way for better clinical diagnosis and finding potential drug targets. We propose a biologically-motivated data-driven approach for the miRNA-disease association prediction, which overcomes the data scarcity problem by exploiting information from multiple data sources. The key idea is to enrich the existing miRNA/disease-protein-coding gene (PCG) associations via a message passing framework, followed by the use of disease ontology information for further feature filtering. The enriched and filtered PCG associations are then used to construct the inter-connected miRNA-PCG-disease network to train a structural deep network embedding (SDNE) model. Finally, the pre-trained embeddings and the biologically relevant features from the miRNA family and disease semantic similarity are concatenated to form the pair input representations to a Random Forest classifier whose task is to predict the miRNA-disease association probabilities. We present large-scale comparative experiments, ablation, and case studies to showcase our approach's superiority. Besides, we make the model prediction results for 1618 miRNAs and 3679 diseases, along with all related information, publicly available at  http://software.mpm.leibniz-ai-lab.de/ to foster assessments and future adoption.

Prognostic biomarkers of cutaneous melanoma

BACKGROUND/PURPOSE

Melanomas account for only approximately 4% of diagnosed skin cancers in the United States but are responsible for the majority of deaths caused by skin cancer. Both genetic factors and ultraviolet (UV) radiation exposure play a role in the development of melanoma. Although melanomas have a strong propensity to metastasize when diagnosed late, melanomas that are diagnosed and treated early pose a low mortality risk. In particular, the identification of patients with increased metastatic risk, who may benefit from early adjuvant therapies, is crucial, especially given the advent of new melanoma treatments. However, the accuracy of classic clinical and histological variables, including the Breslow thickness, presence of ulceration, and lymph node status, might not be sufficient to identify such individuals. Thus, there is a need for the development of additional prognostic melanoma biomarkers that can improve early attempts to stratify melanoma patients and reliably identify high-risk subgroups with the aim of providing effective personalized therapies.

METHODS

In our current work, we discuss and assess emerging primary melanoma tumor biomarkers and prognostic circulating biomarkers.

RESULTS

Several promising biomarkers show prognostic value (eg, exosomal MIA (ie, melanoma inhibitory activity), serum S100B, AMLo signatures, and mRNA signatures); however, the scarcity of reliable data precludes the use of these biomarkers in current clinical applications.

CONCLUSION

Further research is needed on several promising biomarkers for melanoma. Large-scale studies are warranted to facilitate the clinical translation of prognostic biomarker applications for melanoma in personalized medicine.

Evaluation of miRNA-21 and CA-125 as a promising diagnostic biomarker in patients with ovarian cancer

Introduction/objective

Ovarian cancer is the 6th leading cause of mortality in women, killing more women than any other reproductive system cancer. We studied the expression of serum micro-ribonucleic acid-21 (miRNA-21) in ovarian cancer patients and explored associations with diagnosis, clinicopathological parameters, and prognosis.

Methods

Real-time fluorescence-quantitative polymerase chain reaction was used to examine the relative expression of miRNA-21 in serum. Cancer antigen 125 (CA-125) levels were measured using an enzyme immunoassay test kit (ELISA).

Results

Serum miR-21 expression was significantly elevated in ovarian cancer patients compared to controls (p < 0.001). The same was true for CA-125 serum levels, which were also significantly in cancer patients (p < 0.001). The sensitivity and specificity of miR-21 detection in the diagnosis of ovarian cancer were 96%, 88% versus 74%, and 80% for CA-125.

Conclusions

miR-21 is highly expressed in the serum of ovarian cancer patients and may be important in the development and progression of ovarian cancer, with more sensitivity and specificity than CA-125. Our results suggest that circulating serum miRNA-21 is a promising tumor marker for use in the diagnosis and prognosis of ovarian cancer.

miRNAs in Cancer (Review of Literature)

MicroRNAs (miRNAs) are short, noncoding, single-stranded RNA molecules that regulate gene expression at the post-transcriptional level by binding to mRNAs. miRNAs affect the course of processes of fundamental importance for the proper functioning of the organism. These processes include cell division, proliferation, differentiation, cell apoptosis and the formation of blood vessels. Altered expression of individual miRNAs has been shown in numerous cancers, which may indicate the oncogenic or suppressor potential of the molecules in question. This paper discusses the current knowledge about the possibility of using miRNA as a diagnostic marker and a potential target in modern anticancer therapies.

Importance of Circ0009910 in colorectal cancer pathogenesis as a possible regulator of miR-145 and PEAK1

Introduction

Colorectal cancer (CRC) is one of the most frequent neoplasms in the world. Based on the emerging role of noncoding RNAs, particularly circular RNAs in pathogenesis of cancers, we designed this study to inspect the expression levels of a circ0009910-mediated regulatory pathway in colorectal cancer.

Methods

After bioinformatics analyses and construction of putative circ0009910/ miR-145-5p/PEAK1 pathway, the expression levels of these components were evaluated in 50 CRC tissues and adjacent specimens by quantitative real-time PCR. Moreover, we appraised the correlation coefficients between these transcripts and calculated the correlation between circ0009910 expression levels with clinicopathological features of patients.

Results

Circ0009910 and PEAK1 were significantly upregulated, while miR-145-5p was decreased in CRC samples compared with adjacent tissues (p < 0.05). Moreover, statistically significant correlations were observed between expression levels of circ0009910, miR-145-5p, and PEAK1. We also reported considerable correlations between circ0009910 expression and clinicopathological parameters including sex and perineural invasion. Finally, ROC curve analysis showed circ0009910 level as a discriminative biomarker for CRC.

Conclusion

For the first time, we could introduce circ0009910 as an important biomarker in CRC. Collectively, this investigation helped us to identify a newly diagnosed pathway in CRC that can be a potential axis for designing effective drugs for treatment of CRC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02378-0.

MicroRNA characteristics in epithelial ovarian cancer

The purpose of the current study was to clarify differences in microRNA expression according to clinicopathological characteristics, and to investigate if miRNA profiles could predict cytoreductive outcome in patients with FIGO stage IIIC and IV ovarian cancer. Patients enrolled in the Pelvic Mass study between 2004 and 2010, diagnosed and surgically treated for epithelial ovarian cancer, were used for investigation. MicroRNA was profiled from tumour tissue with global microRNA microarray analysis. Differences in miRNA expression profiles were analysed according to histologic subtype, FIGO stage, tumour grade, type I or II tumours and result of primary cytoreductive surgery. One microRNA, miR-130a, which was found to be associated with serous histology and advanced FIGO stage, was also validated using data from external cohorts. Another seven microRNAs (miR-34a, miR-455-3p, miR-595, miR-1301, miR-146-5p, 193a-5p, miR-939) were found to be significantly associated with the clinicopathological characteristics (p ≤ 0.001), in our data, but mere not similarly significant when tested against external cohorts. Further validation in comparable cohorts, with microRNA profiled using newest and similar methods are warranted.

Polymorphisms in genes involved in breast cancer among Iranian patients

This review gives a summary of the important genetic polymorphisms in breast cancer with a focus on people in Iran. Several single nucleotide polymorphisms were considered as breast cancer susceptibility polymorphisms within genes (STK15, ERRs, ESR1, p53, SEP15, AURKA, SHBG, SRC, FAS, VEGF, XRCC1, GST, NFκB1, XPC, XRCC3, sirtuin-3, NKG2D). Cytosine-adenine repeat (IGF-I), rs3877899, G-2548A, GGC (eRF3a/GSPT1), IVS2nt-124A/G have shown an increased risk of breast cancers and a decreased risk has been observed in 4G/5G (PAI-1), rs6505162, tri-nucleotide (GCG TGFBR1). We observed that the signaling pathways and antioxidant related genes are the main molecular processes associated with breast cancer progression. Further studies on types of polymorphisms in breast cancer could validate the prognostic value of biomarkers.

Anti-Micro RNA-221 a Promising Genetic Therapy of Oral Squamous Cell Carcinoma (SCC-25)

Micro-RNA-221(miR-221) is one of oncogenic miRNAs that plays a vital role in the development and progression of oral cancers. The aim of this study is to introduce a new gene therapy for oral squamous cell carcinoma by blocking the expression of oncogenic miR-221 by its inhibitor. The present work was performed on squamous cell carcinoma cell line SCC-25 and anti-miR-221 was delivered to the cells using an ultrasound micro bubbles. Assessment of the effect of miR-221 inhibitor on SCC-25 cells was done using MTT assay, cell cycle analysis and apoptosis detection. In addition, reverse transcription-polymerase chain reaction was also used to detect the expression -miR-221 and its target genes. Using ANOVA, statistical analysis of the results showed significant inhibition of cell viability with and induction of cell apoptosis of SCC-25 cell line after transfection. Moreover, the expression of miR-221, Epidermal growth factor receptor (EGFR) and CDKNIB/p27 were downregulated without significant difference. Transfection of SCC-25 by inhibitor of miR-221 resulting in blockage of its expression leading to arresting of tumor growth. These results proved the effective role of micro-RNA inhibitors as novel therapeutic agent for oral cancers.

Candidate RNA biomarkers in biofluids for early diagnosis of ovarian cancer: A systematic review

Ovarian cancer is often diagnosed in an advanced stage and is associated with a high mortality rate. It is assumed that early detection of ovarian cancer could improve patient outcomes. Unfortunately, effective screening methods for early diagnosis of ovarian cancer are still lacking. Extracellular RNAs circulating in human biofluids can reliably be measured and are emerging as potential biomarkers in cancer. In this systematic review, we present 75 RNA biomarkers detectable in human biofluids that have been studied for early diagnosis of ovarian cancer. The majority of these markers are microRNAs identified using RT-qPCR or microarrays in blood-based fluids. A handful of studies used RNA-sequencing and explored alternative fluids, such as urine and ascites. Candidate RNA biomarkers that were more abundant in biofluids of ovarian cancer patients compared to controls in at least two independent studies include miR-21, the miR-200 family, miR-205, miR-10a and miR-346. Amongst the markers confirmed to be lower in at least two studies are miR-122, miR-193a, miR-223, miR-126 and miR-106b. While these biomarkers show promising diagnostic potential, further validation is required before implementation in routine clinical care. Challenges related to biomarker validation and reflections on future perspectives to accelerate progress in this field are discussed.

The microRNA miR-29c-5p inhibits cell proliferation and migration by targeting TMEM98 in head and neck carcinoma

Head and neck squamous cell carcinoma (HNSCC), which occurs frequently worldwide, is characterized by high risk of metastasis. MicroRNAs (miRNAs) play crucial roles in tumorigenesis and cancer development. In this study, miR-29c-5p was identified using three high throughput microarrays. We measure miR-29c-5p expression in HNSCC tissues and cell lines. To determine the function of miR-29c-5p in HNSCC, we evaluated its effects in vitro on cell proliferation, the cell cycle, apoptosis, and cell migration. We employed a mouse tumor xenograft model to determine the effects of miR-29c-5p on tumors generated by HNSCC cell lines. The miR-29c-5p expression was lower in HNSCC tissues than in normal tissues. Upregulated miR-29c-5p expression in HNSCC cells inhibited migration and arrested cells in the G2/M phase of the cell cycle. Further, upregulated miR-29c-5p expression inhibited the proliferation of HNSCC cells in vivo and in vitro. In addition, transmembrane protein 98 (TMEM98) was identified as a direct target of miR-29c-5p by using a luciferase reporter assay. These findings provide new insights that link the regulation of miR-29c-5p expression to the malignant phenotype of HNSCC and suggest that employing miR-29c-5p may serve as a therapeutic strategy for managing patients with HNSCC.

Long Non-Coding RNA SNHG14 Impedes Viability, Migration and Invasion of Endometrial Carcinoma Cells Through Modulating miR-93-5p/ZBTB7A Axis

Background

The function of long non-coding RNA small nucleolar RNA host gene 14 (SNHG14) in endometrial carcinoma (EC) has not been thoroughly reported. This research is designed to research the action mechanism of SNHG14 in EC development.

Methods

The expression of SNHG14 was estimated in The Cancer Genome Atlas and was verified by qRT-PCR in EC tissues. The correlation between SNHG14 expression and clinicopathological features of EC patients was analyzed. Cell viability, wound healing rate, and relative invasion rate were examined by MTT, wound healing, and transwell assay. StarBase, TargetScan, RNA pull-down, and dual luciferase reporter gene (DLR) assay were conducted to analyze the relationship among SNHG14, miR-93-5p and ZBTB7A.

Results

SNHG14 was underexpressed in EC. SNHG14 expression was significantly relevant to menstruation, FIGO stage, histological grade and lymphatic metastasis of EC patients. SNHG14 overexpression hampered viability, migration and invasion of EC cells. SNHG14 functioned as a sponge for miR-93-5p, and miR-93-5p inhibition restrained cell viability, migration and invasion in EC. In addition, miR-93-5p directly targeted to ZBTB7A, which was underexpressed in EC. The suppressive action of SNHG14 overexpression on the viability, migration and invasion of EC cells was partly rescued by miR-93-5p overexpression or ZBTB7A silencing.

Conclusion

LncRNA SNHG14 hampered the viability, migration and invasion of EC cells via modulating miR-93-5p/ZBTB7A axis.

Identification of miRNA signatures for kidney renal clear cell carcinoma using the tensor-decomposition method

Cancer is a highly complex disease caused by multiple genetic factors. MicroRNA (miRNA) and mRNA expression profiles are useful for identifying prognostic biomarkers for cancer. Kidney renal clear cell carcinoma (KIRC), which accounts for more than 70% of all renal malignant tumour cases, was selected for our analysis. Traditional methods of identifying cancer prognostic markers may not be accurate. Tensor decomposition (TD) is a useful method uncovering the underlying low-dimensional structures in the tensor. The TD-based unsupervised feature extraction method was applied to analyse mRNA and miRNA expression profiles. Biological annotations of the prognostic miRNAs and mRNAs were examined utilizing the pathway and oncogenic signature databases DIANA-miRPath and MSigDB. TD identified the miRNA signatures and the associated genes. These genes were found to be involved in cancer-related pathways, and 23 genes were significantly correlated with the survival of KIRC patients. We demonstrated that the results are robust and not highly dependent upon the databases we selected. Compared with traditional supervised methods tested, TD achieves much better performance in selecting prognostic miRNAs and mRNAs. These results suggest that integrated analysis using the TD-based unsupervised feature extraction technique is an effective strategy for identifying prognostic signatures in cancer studies.

MicroRNA-224 (rs188519172 A>G) Gene Variability is Associated with a Decreased Susceptibility to Coronary Artery Disease: A Case-Control Study

AIM

The microRNAs regulate the expression of multiple genes involved in diseases such as cancer, diabetes and cardiovascular disease. In this study, we have investigated the association between the miR-224 gene polymorphism (rs188519172A>G) and susceptibility of coronary artery disease CAD.

METHODOLOGY

Hundred CAD patients and 100-matched healthy control were included. Genotyping of the miR-224 (rs188519172A>G) polymorphism was performed using Amplification refractory mutation system PCR method (ARMS-PCR).

RESULTS

A significant difference was observed in the genotype distribution among CAD patients and healthy controls (P=0.018). The frequencies of all three genotypes GG, GA, AA reported in the patient's samples were 33%, 66% and 01%, and in the healthy controls samples, were 16%, 82% and 2% respectively. A multivariate analysis based on logistic regression was conducted for each group to estimate the association between miR-224 rs188519172 genotypes and risk to coronary artery disease. Results show that the miR-224 (rs188519172 A>G) polymorphism was associated with a decreased risk to CAD in a codominant model, GA genotype vs. GG (OR = 0.39 (95 % CI, 0.19-0.76), RR 0.58 (0.38-0.90, P=0.006). In the dominant model, (GA+AA vs. GG), there was also a significant association with the OR=0.38 (95 % CI (0.19-0.76), RR 0.58 (0.38-0.89), and P=0.006. Whereas, in the recessive model, (GG+GA vs. AA), there was no significant association of CAD with OR=0.49 (95% CI (0.044-5.54), RR 0.74 (0.33-1.68), and P=0.48.

CONCLUSION

Our findings indicated that miR-224 (rs188519172) GA genotype is associated with a decreased susceptibility to CAD.

MicroRNAs in gastric cancer: Biomarkers and therapeutic targets

MicroRNAs (miRNAs) are a group of non-coding RNAs that have critical roles in regulation of expression of genes. They can inhibit or decrease expression of target genes mostly via interaction with 3' untranslated region of their targets. Their crucial roles in the regulation of expression of tumor suppressor genes and oncogenes have potentiated them as contributors in tumorigenesis. Moreover, their stability in body fluids has enhanced their potential as cancer biomarkers. In the present review article, we describe the role of miRNAs in the pathogenesis of gastric cancer and advances in application of miRNAs as biomarkers and therapeutic targets in this kind of malignancy.

Delivery of dual miRNA through CD44-targeted mesoporous silica nanoparticles for enhanced and effective triple-negative breast cancer therapy

The development of new therapeutic strategies to target triple-negative breast cancer (TNBC) is in much demand to overcome the roadblocks associated with the existing treatment procedures. In this regard, therapies targeting the CD44 receptor have drawn attention for more than a decade. MicroRNAs (miRNAs) modulate post-transcriptional gene regulation and thus, the correction of specific miRNA alterations using miRNA mimics or antagomiRs is an emerging strategy to normalize the genetic regulation in the tumor microenvironment. It has been acknowledged that miR-34a is downregulated and miR-10b is upregulated in TNBC, which promotes tumorigenesis and metastatic dissemination. However, there are a few barriers related to miRNA delivery. Herein, we have introduced tailored mesoporous silica nanoparticles (MSNs) for the co-delivery of miR-34a-mimic and antisense-miR-10b. MSN was functionalized with a cationic basic side chain and then loaded with the dual combination to overexpress miR-34a and downregulate miR-10b simultaneously. Finally, the loaded MSNs were coated with an hyaluronic acid-appended PEG-PLGA polymer for specific targeting. The cellular uptake, release profile, and subsequent effect in TNBC cells were evaluated. In vitro and in vivo studies demonstrated high specificity in TNBC tumor targeting, leading to efficient tumor growth inhibition as well as the retardation of metastasis, which affirmed the clinical application potential of the system.

The Significance of MicroRNAs Expression in Regulation of Extracellular Matrix and Other Drug Resistant Genes in Drug Resistant Ovarian Cancer Cell Lines

Ovarian cancer rates the highest mortality among all gynecological malignancies. The main reason for high mortality is the development of drug resistance. It can be related to increased expression of drug transporters and increased expression of extracellular matrix (ECM) proteins. Our foremost aim was to exhibit alterations in the miRNA expression levels in cisplatin (CIS), paclitaxel (PAC), doxorubicin (DOX), and topotecan (TOP)-resistant variants of the W1 sensitive ovarian cancer cell line-using miRNA microarray. The second goal was to identify miRNAs responsible for the regulation of drug-resistant genes. According to our observation, alterations in the expression of 40 miRNAs were present. We could observe that, in at least one drug-resistant cell line, the expression of 21 miRNAs was upregulated and that of 19 miRNAs was downregulated. We identified target genes for 22 miRNAs. Target analysis showed that miRNA regulates key genes responsible for drug resistance. Among others, we observed regulation of the ATP-binding cassette subfamily B member 1 gene (ABCB1) in the paclitaxel-resistant cell line by miR-363 and regulation of the collagen type III alpha 1 chain gene (COL3A1) in the topotekan-resistant cell line by miR-29a.

Downregulation of miR-34a Promotes Proliferation and Inhibits Apoptosis of Rat Osteoarthritic Cartilage Cells by Activating PI3K/Akt Pathway

Objective

To elucidate the expression and function of miR-34a in rat osteoarthritic cartilage cells, and further to explore its mechanism.

Material and Methods

Rat model of osteoarthritis was constructed and knee joint cartilage cells were isolated in vitro. Immunocytochemical staining was used for identification. qRT-PCR was used to detect the expression of miR-34a in cartilaginous tissues and cartilage cells. Cartilage cells were divided into blank control (BC), negative control (NC), miR-34a inhibitor (34aI), osteoarthritis model (OA), osteoarthritis model + negative control (OA + NC) and osteoarthritis model + miR-34a inhibitor (OA + 34aI) groups. Cell proliferation was detected by CCK-8 and colony formation assays. Cell apoptosis was studied by flow cytometry and Western blot. PI3K/AKT-pathway-related proteins were also analyzed by Western blot. To further validate the effect of miR-34a on the PI3K/Akt pathway, the cartilage cells were divided into blank control (BC), osteoarthritis model (OA), osteoarthritis model + miR-34a inhibitor (OA + 34aI), osteoarthritis model + PI3K activator (OA + IGF-1) and osteoarthritis model + miR-34a inhibitor + PI3K inhibitor (OA + 34aI + LY) groups, the experiments above were repeated.

Results

The expression of miR-34a in cartilaginous tissues and cells of osteoarthritis model was significantly higher than that in normal (p < 0.05). After silencing miR-34a gene, the cell proliferation and proteins expression of PI3K/Akt pathway were increased, while the apoptosis rate and expression of apoptosis-related proteins were decreased. Addition of PI3K activator also evidently promoted proliferation and inhibited apoptosis. The protein expression of Bax, Cleaved caspase-3 and Cleaved caspase-9 were dramatically decreased, while the ratios of p-PI3K/PI3K and p-Akt/Akt were increased in OA + IGF-1 group.

Conclusion

Downregulation of miR-34a regulated proliferation and apoptosis of cartilage cells by activating PI3K/Akt pathway, providing a potential therapeutic approach for the treatment of osteoarthritis.

Evaluation of miR-22 and miR-21 as diagnostic biomarkers in patients with epithelial ovarian cancer

Among the 11 most common cancers, ovarian cancer is the fifth leading cause of death after lung, breast, colorectal and pancreatic cancer. Although diagnosis of ovarian cancer in early stages is followed by various successful treatments, no accurate and reliable method is available at present. Currently microRNAs are being explored as signature biomarkers for early detection of various types of cancer. However little information is available on expression and correlation of microRNA in ovarian cancer. In this study, we have chosen two microRNA on the basis of their altered frequency in epithelial ovarian cancer cases. The main objective of this study is to evaluate the expression of microRNA-22 and microRNA-21 along with various clinicopathological parameters. Expression level of microRNA-22 and microRNA-21 in different stages and subtypes of epithelial ovarian carcinoma has been analyzed to find out its role as a potential diagnostic biomarker. Present study has been conducted in the serum of 80 epithelial ovarian cancer patients and 80 age matched healthy women. Quantitative real time PCR was used to compare the expression of miR-22 and miR-21 between the cases and control groups. Statistical analysis showed 7.85-fold increase in miR-21 expression and 2.1-fold reduction in miR-22 expression of ovarian cancer patients. Increased serum level of miR-21 in ovarian cancer patients and decreased level of miR-22 has been correlated with advanced international federation of gynecology and obstetrics (FIGO) stage and histological sub types of epithelial ovarian cancer. Serous ovarian carcinoma was the most common cancer in the present study. Calculated fold change value for miR-21 was 3.98 and  - 2.86 for miR-22 in serous ovarian cancer. Fold change value in the miR-21 expression in advanced stage was 6.29 and 4.25 in early stage. Whereas lower calculated fold change was observed for miR-22 in advanced stage than in early stage (- 2.16). Present study revealed up-regulated expression of miR-21 and down regulated expression of miR-22 in the serum of epithelial ovarian cancer patients. Both of these could be validated as good diagnostic biomarkers for early detection of ovarian cancer.

MicroRNA and transcription factor co-regulatory networks and subtype classification of seminoma and non-seminoma in testicular germ cell tumors

Recent studies have revealed that feed-forward loops (FFLs) as regulatory motifs have synergistic roles in cellular systems and their disruption may cause diseases including cancer. FFLs may include two regulators such as transcription factors (TFs) and microRNAs (miRNAs). In this study, we extensively investigated TF and miRNA regulation pairs, their FFLs, and TF-miRNA mediated regulatory networks in two major types of testicular germ cell tumors (TGCT): seminoma (SE) and non-seminoma (NSE). Specifically, we identified differentially expressed mRNA genes and miRNAs in 103 tumors using the transcriptomic data from The Cancer Genome Atlas. Next, we determined significantly correlated TF-gene/miRNA and miRNA-gene/TF pairs with regulation direction. Subsequently, we determined 288 and 664 dysregulated TF-miRNA-gene FFLs in SE and NSE, respectively. By constructing dysregulated FFL networks, we found that many hub nodes (12 out of 30 for SE and 8 out of 32 for NSE) in the top ranked FFLs could predict subtype-classification (Random Forest classifier, average accuracy ≥90%). These hub molecules were validated by an independent dataset. Our network analysis pinpointed several SE-specific dysregulated miRNAs (miR-200c-3p, miR-25-3p, and miR-302a-3p) and genes (EPHA2, JUN, KLF4, PLXDC2, RND3, SPI1, and TIMP3) and NSE-specific dysregulated miRNAs (miR-367-3p, miR-519d-3p, and miR-96-5p) and genes (NR2F1 and NR2F2). This study is the first systematic investigation of TF and miRNA regulation and their co-regulation in two major TGCT subtypes.

Expression and Role of MicroRNA-663b in Childhood Acute Lymphocytic Leukemia and its Mechanism

Recent studies have shown that microRNAs (miRNAs) play a key role in various malignant tumors. MiR-663b has been found to have important roles in several cancers, however, the role of miR-663b in T cell acute lymphocytic leukemia (T-ALL) remains unclear. Therefore, we speculated that miR-663b might also play a crucial role in the development and process of T-ALL. In the present study, we found that miR-663b was up-regulated in the blood of children with T-ALL and T-ALL cell lines. TargetScan and dual luciferase reporter assay results showed that CD99 was a direct target of miR-663b. In order to further study the biological function of miR-663b in the development of T-ALL and to clarify its potential molecular mechanism, we detected the changes in proliferation, apoptosis, migration, and invasion of T-ALL cell line Jurkat before and after miR-663b inhibitor transfection. We found that miR-663b inhibitor inhibited Jurkat cell proliferation and induced apoptosis. In addition, miR-663b inhibitor repressed Jurkat cell migration and invasion. All these effects of miR-663b inhibitor on Jurkat cells were eliminated by CD99-silencing. These results have provided a new theoretical basis and strategy for the diagnosis and treatment of T-ALL.

LHX2 promotes malignancy and inhibits autophagy via mTOR in osteosarcoma and is negatively regulated by miR-129-5p

The transcript factor LHX2 is dysregulated in many cancers but its role in osteosarcoma (OS) remains unclear. In this study, we confirm that LHX2 is up-regulated in osteosarcoma, and that its silencing inhibits OS malignancy and induces autophagy via mTOR signaling. We further demonstrate that miR-129-5p negatively regulates LHX2 and suppresses the malignant phenotypes of OS. LHX2 overexpression could restore the malignant phenotypes. In conclusion, LHX2 regulates tumorigenesis and autophagy via mTOR in OS and is negatively regulated by miR-129-5p. Targeting the miR-129-5p/LHX2/mTOR axis therefore represents a novel therapeutic strategy for OS treatment.

A hierarchical integration deep flexible neural forest framework for cancer subtype classification by integrating multi-omics data

Background

Cancer subtype classification attains the great importance for accurate diagnosis and personalized treatment of cancer. Latest developments in high-throughput sequencing technologies have rapidly produced multi-omics data of the same cancer sample. Many computational methods have been proposed to classify cancer subtypes, however most of them generate the model by only employing gene expression data. It has been shown that integration of multi-omics data contributes to cancer subtype classification.

Results

A new hierarchical integration deep flexible neural forest framework is proposed to integrate multi-omics data for cancer subtype classification named as HI-DFNForest. Stacked autoencoder (SAE) is used to learn high-level representations in each omics data, then the complex representations are learned by integrating all learned representations into a layer of autoencoder. Final learned data representations (from the stacked autoencoder) are used to classify patients into different cancer subtypes using deep flexible neural forest (DFNForest) model.Cancer subtype classification is verified on BRCA, GBM and OV data sets from TCGA by integrating gene expression, miRNA expression and DNA methylation data. These results demonstrated that integrating multiple omics data improves the accuracy of cancer subtype classification than only using gene expression data and the proposed framework has achieved better performance compared with other conventional methods.

Conclusion

The new hierarchical integration deep flexible neural forest framework(HI-DFNForest) is an effective method to integrate multi-omics data to classify cancer subtypes.

The miR-205-5p/BRCA1/RAD17 Axis Promotes Genomic Instability in Head and Neck Squamous Cell Carcinomas

Defective DNA damage response (DDR) is frequently associated with tumorigenesis. Abrogation of DDR leads to genomic instability, which is one of the most common characteristics of human cancers. TP53 mutations with gain-of-function activity are associated with tumors under high replicative stress, high genomic instability, and reduced patient survival. The BRCA1 and RAD17 genes encode two pivotal DNA repair proteins required for proper cell-cycle regulation and maintenance of genomic stability. We initially evaluated whether miR-205-5p, a microRNA (miRNA) highly expressed in head and neck squamous cell carcinoma (HNSCC), targeted BRCA1 and RAD17 expression. We found that, in vitro and in vivo, BRCA1 and RAD17 are targets of miR-205-5p in HNSCC, leading to inefficient DNA repair and increased chromosomal instability. Conversely, miR-205-5p downregulation increased BRCA1 and RAD17 messenger RNA (mRNA) levels, leading to a reduction in in vivo tumor growth. Interestingly, miR-205-5p expression was significantly anti-correlated with BRCA1 and RAD17 targets. Furthermore, we documented that miR-205-5p expression was higher in tumoral and peritumoral HNSCC tissues than non-tumoral tissues in patients exhibiting reduced local recurrence-free survival. Collectively, these findings unveil miR-205-5p's notable role in determining genomic instability in HNSCC through its selective targeting of BRCA1 and RAD17 gene expression. High miR-205-5p levels in the peritumoral tissues might be relevant for the early detection of minimal residual disease and pre-cancer molecular alterations involved in tumor development.

miRDRN-miRNA disease regulatory network: a tool for exploring disease and tissue-specific microRNA regulatory networks

BACKGROUND

MicroRNA (miRNA) regulates cellular processes by acting on specific target genes, and cellular processes proceed through multiple interactions often organized into pathways among genes and gene products. Hundreds of miRNAs and their target genes have been identified, as are many miRNA-disease associations. These, together with huge amounts of data on gene annotation, biological pathways, and protein-protein interactions are available in public databases. Here, using such data we built a database and web service platform, miRNA disease regulatory network (miRDRN), for users to construct disease and tissue-specific miRNA-protein regulatory networks, with which they may explore disease related molecular and pathway associations, or find new ones, and possibly discover new modes of drug action.

METHODS

Data on disease-miRNA association, miRNA-target association and validation, gene-tissue association, gene-tumor association, biological pathways, human protein interaction, gene ID, gene ontology, gene annotation, and product were collected from publicly available databases and integrated. A large set of miRNA target-specific regulatory sub-pathways (RSPs) having the form (T, G 1, G 2) was built from the integrated data and stored, where T is a miRNA-associated target gene, G 1 (G 2) is a gene/protein interacting with T (G 1). Each sequence (T, G 1, G 2) was assigned a p-value weighted by the participation of the three genes in molecular interactions and reaction pathways.

RESULTS

A web service platform, miRDRN (http://mirdrn.ncu.edu.tw/mirdrn/), was built. The database part of miRDRN currently stores 6,973,875 p-valued RSPs associated with 116 diseases in 78 tissue types built from 207 diseases-associated miRNA regulating 389 genes. miRDRN also provides facilities for the user to construct disease and tissue-specific miRNA regulatory networks from RSPs it stores, and to download and/or visualize parts or all of the product. User may use miRDRN to explore a single disease, or a disease-pair to gain insights on comorbidity. As demonstrations, miRDRN was applied: to explore the single disease colorectal cancer (CRC), in which 26 novel potential CRC target genes were identified; to study the comorbidity of the disease-pair Alzheimer's disease-Type 2 diabetes, in which 18 novel potential comorbid genes were identified; and, to explore possible causes that may shed light on recent failures of late-phase trials of anti-AD, BACE1 inhibitor drugs, in which genes downstream to BACE1 whose suppression may affect signal transduction were identified.

Effect of estrogen-related receptor silencing on miRNA protein machinery expression, global methylation, and deacetylation in bank vole (Myodes glareolus) and mouse tumor Leydig cells

The function of estrogen-related receptor (ERR) in testicular cells is at the beginning of exploration. Our previous findings showed that expression pattern of estrogen-related receptor (ERR) in mouse Leydig cell depends on physiological status of the cell. Exogenous hormones/hormonally active chemicals affect ERR expression. In Leydig cells in vitro, ERRα and ERRγ show opposing regulatory properties. The aim of this study was to examine the role of ERR in epigenetic processes in cells with altered level of secreted estrogens; mouse tumor Leydig cells and bank vole Leydig cells, respectively. In Leydig cells, ERRα and ERRγ were silenced via siRNA. mRNA and protein expression and protein localization of molecules required for miRNA biogenesis and function (Exportin 5, Dicer, Drosha and Argonaute 2; Ago2) were studied with the use of qRT-PCR, Western blotting, and immunohistochemistry. Global DNA methylation and histone deacetylation status together with estradiol secretion were determined with fluorometric, and immunoenzymatic assays. Regardless of ERR type knockdown in tumor Leydig cells, downregulation (P < 0.05; P < 0.01; P < 0.001) of Exportin5, Dicer, Drosha but not Ago2 was revealed while at protein level only Drosha was downregulated (P < 0.01) by both ERRα and ERRγ. Oppositely, Exportin5, Dicer and Ago2 showed ERR type-dependent regulation (downregulation; P < 0.01 by ERRα and upregulation; P < 0.01; P < 0.001 by ERRγ). In ERR-silenced vole Leydig cells, expression of Exportin5, endonucleases and Ago2 was not changed. Immunolocalization of Dicer and Ago2 was independent of the cell origin in contrast to localization of Exportin5 and Drosha which was dependent on the cell origin and ERR type knockdown. Absence of ERR effected on cell methylation status (ERRα increased it; P < 0.01 while ERRγ decreased it; P < 0.01, P < 0.001) but it not changed histone deacetylates activity. ERRα and ERRγ silencing decreased (P < 0.01, P < 0.001) estradiol secretion in both tumor and vole Leydig cells. In mouse and bank vole Leydig cell, Exportin5, Dicer, Drosha and Ago2 expression as well as methylation status are regulated by ERR in a manner related to receptor type, molecule type, cell origin and level of secreted estrogen.

Regulation of GKN1 expression in gastric carcinogenesis: A problem to resolve (Review)

Gastrokine 1 (GKN1) is a protein expressed on the surface mucosa cells of the gastric antrum and fundus, which contributes to maintaining gastric homeostasis, inhibits inflammation and is a tumor suppressor. The expression of GKN1 decreases in mucosa that are either inflamed or infected by Helicobacter pylori, and is absent in gastric cancer. The measurement of circulating GKN1 concentration, the protein itself, or the mRNA in gastric tissue may be of use for the early diagnosis of cancer. The mechanisms that modulate the deregulation or silencing of GKN1 expression have not been completely described. The modification of histones, methylation of the GKN1 promoter, or proteasomal degradation of the protein have been detected in some patients; however, these mechanisms do not completely explain the absence of GKN1 or the reduction in GKN1 levels. Only NKX6.3 transcription factor has been shown to be a positive modulator of GKN1 transcription, although others also have an affinity with sequences in the promoter of this gene. While microRNAs (miRNAs) are able to directly or indirectly regulate the expression of genes at the post‑transcriptional level, the involvement of miRNAs in the regulation of GKN1 has not been reported. The present review analyzes the information reported on the determination of GKN1 expression and the regulation of its expression at the transcriptional, post‑transcriptional and post‑translational levels; it proposes an integrated model that incorporates the regulation of GKN1 expression via transcription factors and miRNAs in H. pylori infection.

Efficient Self-Assembled MicroRNA Delivery System Consisting of Cholesterol-Conjugated MicroRNA and PEGylated Polycationic Polymer for Tumor Treatment

MicroRNA (miR), a key molecule involved in endogenous RNA interference, is a promising therapeutic agent. In vivo delivery of miR, however, is a major factor limiting its application because its polyanionic nature and vulnerability to breakdown make delivery of miR to targeted lesions difficult. To overcome these challenges, we developed a self-assembled miR delivery system consisting of cholesterol-conjugated miR and polyethylene glycol-grafted polyethylene imine. Nanosized complexes of miR with polyethylene imine, which protected miR and its delivery into targeted lesions in vivo, were successfully synthesized by polyethylene glycol grafting. The hydrophobicity of cholesterol improved the structural stability of the complex, preventing the loss of miR. Here, we report the preparation of this self-assembled complex. We examined the delivery efficiency and validated the therapeutic efficacy of the complex. In conclusion, our miR delivery system shows considerable potential for effective in vivo delivery of miR.

miR-186-5p promotes cell growth, migration and invasion of lung adenocarcinoma by targeting PTEN

OBJECTIVE

To explore the expression of miR-186-5p in lung adenocarcinoma (LUAD) and its possible function associated with cancer cell proliferation, migration and invasion.

METHODS

MiR-186-5p expression levels in LUAD samples, human LUAD cell lines H1299 and NCI-H1975, and normal human lung epithelial cell line BEAS-IB were assessed by quantitative real-time PCR (qRT-PCR). H1299 and NCI-H1975 cells were transfected with miR-186-5p mimic or miRNA negative control. CCK-8 assay was performed to evaluate the cell proliferation. Transwell assay and transwell-matrigel™ invasion assay were applied to assess the migration and invasion abilities of H1299 and NCI-H1975 cells.

RESULTS

miR-186-5p expression was significantly up-regulated in LUAD tumor tissues and LUAD cell lines as compared with tumor-adjacent tissues and normal human lung epithelial cells, respectively. MiR-186-5p overexpression remarkably promoted the proliferation, migration and invasion of LUAD cells. Furthermore, phosphatase and tensin homolog (PTEN) was a direct target of miR-186-5p verified by luciferase reporter assay. Overexpression of PTEN significantly suppressed LUAD cells to proliferate, migrate and invade. MiR-186-5p overexpression-induced LUAD cell phenotype could be partially rescued by co-overexpression of miR-186-5p and PTEN.

CONCLUSION

This study demonstrated that miR-186-5p is up-regulated in LUAD, and functionally associated with cell proliferation, migration and invasion. MiR-186-5p promotes the proliferation, migration and invasion of LUAD cells by targeting PTEN. MiR-186-5p may be utilized as a novel molecular marker and therapeutic target of LUAD.

Scenario and future prospects of microRNAs in gastric cancer: A review

Carcinoma of the stomach is one of the major prevalent and principal causes of cancer-related deaths worldwide. Current advancement in technology has improved the understanding of the pathogenesis and pathology of gastric cancers (GC). But, high mortality rates, unfavorable prognosis and lack of clinical predictive biomarkers provide an impetus to investigate novel early diagnostic/prognostic markers and therapeutic targets for GC, which are sufficiently sensitive to GC. Current biomedical investigations have explored several budding GC biomarker by utilizing serum proteins, natural oncogenic genes during improvement in molecular technologies as microarray, and RNA/DNA-Seq. Recently, small non-coding microRNAs (miRNAs) are becoming vital regulators in oncogenesis pathways and can act as handy clinical biomarkers. The newly introduced class of biomarkers is rising as new molecules for cancer diagnosis and prognosis. For better understanding of the gastric carcinogenesis, miRNAs may help to elucidate the mechanisms of tumor growth and can help to discover novel untimely potent markers for early detection of GC. Here in this review, we summarize the recent research studies supporting the utility of miRNAs as novel early diagnostic/prognostic tools and therapeutic targets. Thus, here we introduce potential future treatment strategies for gastrointestinal (GI) cancers, which indicate the practicality and clinical applications of miRNAs in GC.

Triple Negative Breast Cancer Profile, from Gene to microRNA, in Relation to Ethnicity

Breast cancer is the most frequent cause of cancer-related deaths among women worldwide. It is classified into four major molecular subtypes. Triple-negative breast cancers (TNBCs), a subgroup of breast cancer, are defined by the absence of estrogen and progesterone receptors and the lack of HER-2 expression; this subgroup accounts for ~15% of all breast cancers and exhibits the most aggressive metastatic behavior. Currently, very limited targeted therapies exist for the treatment of patients with TNBCs. On the other hand, it is important to highlight that knowledge of the molecular biology of breast cancer has recently changed the decision-making process regarding the course of cancer therapies. Thus, a number of new techniques, such as gene profiling and sequencing, proteomics, and microRNA analysis have been used to explore human breast carcinogenesis and metastasis including TNBC, which consequently could lead to new therapies. Nevertheless, based on evidence thus far, genomics profiles (gene and miRNA) can differ from one geographic location to another as well as in different ethnic groups. This review provides a comprehensive and updated information on the genomics profile alterations associated with TNBC pathogenesis associated with different ethnic backgrounds.

Large scale in vivo micro-RNA loss of function screen identified miR-29a, miR-100 and miR-155 as modulators of radioresistance and tumor-stroma communication

Micro RNAs (miR) are master regulators of cellular transcriptome. We aimed to investigate the role of miR regulation on tumor radiosensitivity and development of local tumor recurrence by a novel large-scale in vivo loss of function screen. For stable miR silencing, human A431 tumor cells were transduced with lentiviral constructs against 170 validated human miR (miRzip library). Fractionated radiotherapy (5x6Gy) was applied to A431 miRzip library growing s.c. in NCr nude mice. Enrichment of miRZip and miR expression was assessed using multiplexed qRT-PCR. The modulatory effect of miR on tumor and tumor microenvironment response to ionizing radiation was further evaluated by clonogenic survival, apoptosis (Caspase 3/7), DNA double-strand breaks (DSB, nuclear γH2AX foci), tumor microvessel density (MVD), transcriptome and protein analysis. Fractionated irradiation of the A431 miRzip library led to regression of tumors. However, after a latency period, tumors ultimately progressed and formed local recurrences indicating the survival of a subpopulation of miRzip expressing tumor clones. Among the selected miR for subsequent validation studies, loss of miR-29a, miR-100 and miR-155 was found to enhance clonogenic survival, reduce apoptosis and residual γH2AX foci of irradiated tumor cells. Moreover, knockdown of miR increased tumor angiogenesis correlating with elevated VEGF and TGFα expression levels. This phenomenon was most evident after tumor irradiation in vivo suggesting a critical role for tumor-stroma communication in development of the radioresistant phenotype. Engineering radioresistant tumors in vivo by modulating miR expression may lead to identification of critical targets for conquering local therapy failure.

MicroRNA-181a-5p suppresses cell proliferation by targeting Egr1 and inhibiting Egr1/TGF-β/Smad pathway in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the leading cause of cancer mortality worldwide. Early growth response factor 1 (Egr1) plays a crucial role in cancer progression. However, its precise role in HCC has not been clear. Here, we identified the aggravating role of Egr1 in cell proliferation of HCC firstly. The expression of Egr1 was significantly increased in HCC tissues. Functionally, overexpression of Egr1 enhanced, whereas silenced Egr1 expression attenuated HCC cells proliferation in vitro. Mechanistically, up-regulated Egr1 induced cell proliferation through activating Transforming growth factor (TGF)-β1/Smad signaling pathway concomitantly with upregulation of p-Smad2 and p-Smad3. Secondly, miR-181a-5p was down-regulated in clinical HCC specimens and its expression was inversely correlated with Egr1 expression. Functionally, overexpression of miR-181a-5p inhibited, whereas decreased expression of miR-181a-5p promoted HCC cells proliferation in vitro. Furthermore, we demonstrated that miR-181a-5p overexpression directly suppressed Egr1, resulting in a down-regulated TGF-β1/Smad pathway. Besides, the silenced Egr1 expression could rescue the enhanced cell proliferation induced by miR-181a-5p inhibitor. Thus, we concluded that miR-181a-5p is a negative regulator of Egr1 that can suppress tumor proliferation in HCC through targeting Egr1/TGF-β1/Smad pathway, which may be a potential therapeutic approach of HCC.

Identification and validation of potential prognostic and predictive miRNAs of epithelial ovarian cancer

Background

Ovarian cancer is the leading cause of death by gynecologic cancers in the Western world. The aim of the study was to identify microRNAs (miRNAs) associated with prognosis and/or resistance to chemotherapy among patients with epithelial ovarian cancer.

Methods

Using information from the Pelvic Mass Study we identified a cohort of women with epithelial ovarian cancer. Tumor tissues were then collected and analyzed by global miRNA microarrays. MiRNA profiling was then linked to survival and time to progression using Cox proportional-hazards regression models. Logistic regression models were used for the analysis of resistance to chemotherapy. Our results were validated using external datasets retrieved from the NCBI Gene Expression Omnibus database.

Results

A total of 197 patients with epithelial ovarian cancer were included for miRNA microarray analysis. In multivariate analyses we identified a number of miRNAs significantly correlated with overall survival (miR-1183 (HR: 1.42, 95% CI:1.17–1.74, p = 0.0005), miR-126-3p (HR: 1.38, 95% CI:1.11–1.71, p = 0.0036), time to progression (miR-139-3p (HR: 1.48, 95% CI: 1.13–1.94, p = 0.0047), miR-802 (HR: 0.48, 95% CI: 0.29–0.78, p = 0.0035)), progression free survival (miR-23a-5p (HR:1.32, 95% CI:1.09–1.61, p = 0.004), miR-23a-3p (HR:1.70, 95% CI:1.15–2.51, p = 0.0074), miR-802 (HR: 0.48, 95% CI: 0.29–0.80, p = 0.0048)), and resistance to chemotherapy (miR-1234 (HR: 0.26, 95% CI: 0.11–0.64, p = 0.003)). A few miRNAs identified in our training cohort, were validated in external cohorts with similar results.

Conclusion

Eight miRNAs were identified as significant predictors of overall survival, progression free survival, time to progression, and chemotherapy resistance. A number of these miRNAs were significantly validated using external datasets. Inter-platform and inter-laboratory variations may have influence on the ability to compare and reproduce miRNA results. The use of miRNAs as potential markers of relapse and survival in ovarian cancer warrants further investigation.

The Use of Normal Stem Cells and Cancer Stem Cells for Potential Anti-Cancer Therapeutic Strategy

BACKGROUND

Despite recent advance in conventional cancer therapies including surgery, radiotherapy, chemotherapy, and immunotherapy to reduce tumor size, unfortunately cancer mortality and metastatic cancer incidence remain high. Along with a deeper understanding of stem cell biology, cancer stem cell (CSC) is important in targeted cancer therapy. Herein, we review representative patents using not only normal stem cells as therapeutics themselves or delivery vehicles, but also CSCs as targets for anti-cancer strategy.

METHODS

Relevant patent literatures published between 2005 and 2017 are discussed to present developmental status and experimental results on using normal stem cells and CSCs for cancer therapy and explore potential future directions in this field.

RESULTS

Stem cells have been considered as important element of regenerative therapy by promoting tissue regeneration. Particularly, there is a growing trend to use stem cells as a target drug-delivery system to reduce undesirable side effects in non-target tissues. Noteworthy, studies on CSC-specific markers for distinguishing CSCs from normal stem cells and mature cancer cells have been conducted as a selective anti-cancer therapy with few side effects. Many researchers have also reported the development of various substances with anticancer effects by targeting CSCs from cancer tissues.

CONCLUSION

There has been a continuing increase in the number of studies on therapeutic stem cells and CSC-specific markers for selective diagnosis and therapy of cancer. This review focuses on the current status in the use of normal stem cells and CSCs for targeted cancer therapy. Future direction is also proposed.

Emodin inhibits pancreatic cancer EMT and invasion by up‑regulating microRNA‑1271

Emodin has a direct inhibitory effect on the growth and metastasis of a variety of malignant tumor cells. MicroRNA-1271 (miR-1271) has an extensive tumor-suppression effect by inhibiting epithelial mesenchymal transition (EMT) in tumor cells and induces tumor cell apoptosis. Proceeding with the EMT regulatory mechanism of pancreatic carcinoma, the present study aimed to examine the inhibitory effect of miR-1271 and emodin against invasion and metastasis of pancreatic carcinoma. The expression of EMT-related markers (E-cadherin, ZEB1 and TWIST1) was analyzed by western blotting. mRNA levels of miR-1271, E-cadherin, ZEB1 and TWIST1 in pancreatic tumor cells (SW1990) were measured through reverse transcription-quantitative polymerase chain reaction and cell invasiveness was detected using Transwell assays. In addition, a liver metastatic model was established with an implantation of pancreatic tumor tissue into the spleens of nude mice to study the effect of emodin on pancreatic cancer liver metastasis. In the present study, it was demonstrated that miR-1271 significantly decreased in pancreatic cancer cells and tissues. Twist1 may be a target gene of miR-1271. Emodin could inhibit the proliferation ability of pancreatic cancer cells and increased miR-1271 expression level. Further, we found that miR-1271 significantly inhibited SW1990 cell EMT and invasive ability. We also provided the evidence that emodin inhibited SW1990 cell EMT by raising the level of miR-1271. Moreover, the in vivo experiments have verified the inhibiting effect of emodin against liver metastasis of pancreatic cancer. The data in the present study indicated that emodin inhibited pancreatic cancer EMT and invasion by increasing the content of miR-1271.

Dysregulation of microRNAs in autoimmune diseases: Pathogenesis, biomarkers and potential therapeutic targets

MicroRNAs (miRNAs) are small, single-stranded, endogenous non-coding RNAs that repress the expression of target genes via post-transcriptional mechanisms. Due to their broad regulatory effects, the precisely regulated, spatial-specific and temporal-specific expression of miRNAs is fundamentally important to various biological processes including the immune homeostasis and normal function of both innate and adaptive immune response. Aberrance of miRNAs is implicated in the development of various human diseases, especially cancers. Increasing evidence has revealed a dysregulated expression pattern of miRNAs in autoimmune diseases, among which many play key roles in the pathogenesis. In this review we summarize these findings on miRNA dysregulation implicated in autoimmune diseases, focusing on four representative systemic autoimmune diseases, i.e. systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis and dermatomyositis. The causes of the dysregulation of miRNA expression in autoimmune diseases may include genetic and epigenetic variants, and various environmental factors. Further understanding of miRNA dysregulation and its mechanisms during the development of different autoimmune diseases holds enormous potential to bring about novel therapeutic targets or strategies for these complex human disorders, as well as novel circulating or exosomal miRNA biomarkers.