Modulation of miRNA activity in human cancer: a new paradigm for cancer gene therapy? Cancer Gene Ther. 2008;15:341-355. [PMID: 18369380 DOI: 10.1038/cgt.2008.8]

The crosstalk between miRNAs and signaling pathways in human cancers: Potential therapeutic implications

MicroRNAs (miRNAs) are increasingly recognized as central players in the regulation of eukaryotic physiological processes. These small double stranded RNA molecules have emerged as pivotal regulators in the intricate network of cellular signaling pathways, playing significant roles in the development and progression of human cancers. The central theme in miRNA-mediated regulation of signaling pathways involves their ability to target and modulate the expression of pathway components. Aberrant expression of miRNAs can either promote or suppress key signaling events, influencing critical cellular processes such as proliferation, apoptosis, angiogenesis, and metastasis. For example, oncogenic miRNAs often promote cancer progression by targeting tumor suppressors or negative regulators of signaling pathways, thereby enhancing pathway activity. Conversely, tumor-suppressive miRNAs frequently inhibit oncogenic signaling by targeting key components within these pathways. This complex regulatory crosstalk underscores the significance of miRNAs as central players in shaping the signaling landscape of cancer cells. Furthermore, the therapeutic implications of targeting miRNAs in cancer are substantial. miRNAs can be manipulated to restore normal signaling pathway activity, offering a potential avenue for precision medicine. The development of miRNA-based therapeutics, including synthetic miRNA mimics and miRNA inhibitors, has shown promise in preclinical and clinical studies. These strategies aim to either enhance the activity of tumor-suppressive miRNAs or inhibit the function of oncogenic miRNAs, thereby restoring balanced signaling and impeding cancer progression. In conclusion, the crosstalk between miRNAs and signaling pathways in human cancers is a dynamic and influential aspect of cancer biology. Understanding this interplay provides valuable insights into cancer development and progression. Harnessing the therapeutic potential of miRNAs as regulators of signaling pathways opens up exciting opportunities for the development of innovative cancer treatments with the potential to improve patient outcomes. In this chapter, we provide an overview of the crosstalk between miRNAs and signaling pathways in the context of cancer and highlight the potential therapeutic implications of targeting this regulatory interplay.

MicroRNA-21 promotes head and neck squamous cell carcinoma (HNSCC) induced transition of bone marrow mesenchymal stem cells to cancer-associated fibroblasts

BACKGROUND

Most patients diagnosed with head and neck tumor will present with locally advanced disease, requiring multimodality therapy. Bone marrow-derived mesenchymal stromal cells (BMSCs) respond to a variety of tumor cell-derived signals, such as inflammatory cytokines and growth factors. As a result, the inflammatory tumor microenvironment may lead to the recruitment of BMSCs. Whether BMSCs in the tumor environment are more likely to promote tumor growth or tumor suppression is still controversial. We aimed to determine whether microRNA-21(miR-21) would play a vital role in HNSCC induced transition of human bone marrow mesenchymal stem cells (hBMSCs) to cancer-associated fibroblasts (CAFs).

METHODS

In this study, we used electron microscope to observed exosomes collected from human tissue and two cell lines. We co-cultured hBMSCs with exosomes from FaDu and Cal-27 cells with miR-21 inhibited or not, then assessed cell cycle changes of hBMSCs with flow cytometry and determined expression level of α-SMA and FAP through qRT-PCR and Western blot.

RESULTS

We observed an up-regulation of miR-21 expression in HNSCC tissue and FaDu and Cal-27 cells. Importantly, the exosomes derived from both cells induced CAFs-like characteristics in hBMSCs. while treatment with a miR-21 inhibitor effectively suppressed the transition of hBMSCs to CAFs and reversed the changes in the cell cycle distribution. This suggests that miR-21 plays a crucial role in facilitating the transition of hBMSCs to CAFs and modulating the cell cycle dynamics.

CONCLUSION

Our findings highlight the significance of miR-21 in mediating the communication between HNSCC cells and hBMSCs through exosomes, leading to the promotion of CAFs-like features and alterations in the cell cycle of hBMSCs.

Functionalized nanopores based on hybridization chain reaction: Fabrication and microRNA sensing

Enzyme-free hybridization chain reaction (HCR) technology is often used as a signal amplification tool for the detection of different targets. In this study, an ultrasensitive and label-free method for detecting miRNA-21 was developed using the nanopore ionic current rectification (ICR) technology coupled with HCR technology. The probe oligonucleotide (DNA1) was combined with the gold-coated nanopore through the Au-S bond to form a DNA1-functionalized gold-coated nanopore (DNA1-Au-coated nanopore). Since miRNA-21 is partially complementary to DNA1, it can be selectively recognized by DNA1-functionalized gold-coated nanopores. The target (miRNA-21) can induce the opening of hairpin DNA and HCR reaction after the introduction of hairpin DNA H1 and H2. The concentration of miRNA-21 will affect the combination of H1 and H2 on the inner wall of the nanopore, and its surface charge will change with the internal modification, thereby changing the ion current rectification ratio. Under the condition that the concentration of H1, H2 and HCR reaction time are constant, the change of ICR ratio is linearly correlated with the logarithm of miRNA-21 concentration within a certain range, which shows that the sensing strategy we designed can achieve target miRNA-21 detection. This ultrasensitive miRNA holds great promise in the field of cancer diagnosis.

Targeting miRNAs and Other Non-Coding RNAs as a Therapeutic Approach: An Update

Since the discovery of the first microRNAs (miRNAs, miRs), the understanding of miRNA biology has expanded substantially. miRNAs are involved and described as master regulators of the major hallmarks of cancer, including cell differentiation, proliferation, survival, the cell cycle, invasion, and metastasis. Experimental data indicate that cancer phenotypes can be modified by targeting miRNA expression, and because miRNAs act as tumor suppressors or oncogenes (oncomiRs), they have emerged as attractive tools and, more importantly, as a new class of targets for drug development in cancer therapeutics. With the use of miRNA mimics or molecules targeting miRNAs (i.e., small-molecule inhibitors such as anti-miRS), these therapeutics have shown promise in preclinical settings. Some miRNA-targeted therapeutics have been extended to clinical development, such as the mimic of miRNA-34 for treating cancer. Here, we discuss insights into the role of miRNAs and other non-coding RNAs in tumorigenesis and resistance and summarize some recent successful systemic delivery approaches and recent developments in miRNAs as targets for anticancer drug development. Furthermore, we provide a comprehensive overview of mimics and inhibitors that are in clinical trials and finally a list of clinical trials based on miRNAs.

Aiding Cancer's "Sweet Tooth": Role of Hexokinases in Metabolic Reprogramming

Hexokinases (HKs) convert hexose sugars to hexose-6-phosphate, thus trapping them inside cells to meet the synthetic and energetic demands. HKs participate in various standard and altered physiological processes, including cancer, primarily through the reprogramming of cellular metabolism. Four canonical HKs have been identified with different expression patterns across tissues. HKs 1-3 play a role in glucose utilization, whereas HK 4 (glucokinase, GCK) also acts as a glucose sensor. Recently, a novel fifth HK, hexokinase domain containing 1 (HKDC1), has been identified, which plays a role in whole-body glucose utilization and insulin sensitivity. Beyond the metabolic functions, HKDC1 is differentially expressed in many forms of human cancer. This review focuses on the role of HKs, particularly HKDC1, in metabolic reprogramming and cancer progression.

Therapeutic potential of targeting mirnas to prostate cancer tumors: using psma as an active target

Prostate cancer (PC) is a commonly diagnosed malignancy in men and is associated with high mortality rates. Current treatments for PC include surgery, chemotherapy, and radiation therapy. However, recent advances in targeted delivery systems have yielded promising new approaches to PC treatment. As PC epithelial cells express high levels of prostate-specific membrane antigen (PSMA) on the cell surface, new drug conjugates focused on PSMA targeting have been developed. microRNAs (miRNAs) are small noncoding RNAs that regulate posttranscriptional gene expression in cells and show excellent possibilities for use in developing new therapeutics for PC. PSMA-targeted therapies based on a miRNA payload and that selectively target PC cells enhances therapeutic efficacy without eliciting damage to normal surrounding tissue. This review discusses the rationale for utilizing miRNAs to target PSMA, revealing their potential in therapeutic approaches to PC treatment. Different delivery systems for miRNAs and challenges to miRNA therapy are also explored.

Transcriptional Inhibition of MicroRNA miR-122 by Small Molecules Reduces Hepatitis C Virus Replication in Liver Cells

MicroRNAs (miRNAs) are noncoding RNA molecules of 22-24 nucleotides that are estimated to regulate thousands of genes in humans, and their dysregulation has been implicated in many diseases. MicroRNA-122 (miR-122) is the most abundant miRNA in the liver and has been linked to the development of hepatocellular carcinoma and hepatitis C virus (HCV) infection. Its role in these diseases renders miR-122 a potential target for small-molecule therapeutics. Here, we report the discovery of a new sulfonamide class of small-molecule miR-122 inhibitors from a high-throughput screen using a luciferase-based reporter assay. Structure-activity relationship (SAR) studies and secondary assays led to the development of potent and selective miR-122 inhibitors. Preliminary mechanism-of-action studies suggest a role in the promoter-specific transcriptional inhibition of miR-122 expression through direct binding to the liver-enriched transcription factor hepatocyte nuclear factor 4α. Importantly, the developed inhibitors significantly reduce HCV replication in human liver cells.

MicroRNA binding site variation is enriched in psychiatric disorders

Psychiatric disorders have a polygenic architecture, often associated with dozens or hundreds of independent genomic loci. Most associated loci impact noncoding regions of the genome, suggesting that the majority of disease heritability originates from the disruption of regulatory sequences. While most research has focused on variants that modify regulatory DNA elements, those affecting cis-acting RNA sequences, such as miRNA binding sites, are also likely to have a significant impact. We intersected genome-wide association study (GWAS) summary statistics with the dbMTS database of predictions for miRNA binding site variants (MBSVs). We compared the distributions of MBSV association statistics to non-MBSVs within brain-expressed 3'UTR regions. We aggregated GWAS p values at the gene, pathway, and miRNA family levels to investigate cellular functions and miRNA families strongly associated with each trait. We performed these analyses in several psychiatric disorders as well as nonpsychiatric traits for comparison. We observed significant enrichment of MBSVs in schizophrenia, depression, bipolar disorder, and anorexia nervosa, particularly in genes targeted by several miRNA families, including miR-335-5p, miR-21-5p/590-5p, miR-361-5p, and miR-557, and a nominally significant association between miR-323b-3p MBSVs and schizophrenia risk. We identified evidence for the association between MBSVs in synaptic gene sets in schizophrenia and bipolar disorder. We also observed a significant association of MBSVs in other complex traits including type 2 diabetes. These observations support the role of miRNA in the pathophysiology of psychiatric disorders and suggest that MBSVs are an important class of regulatory variants that have functional implications for many disorders, as well as other complex human traits.

Tunable and Modular miRNA Classifier through Indirect Associative Toehold Strand Displacement

The programmability of nucleic acids allows detection devices with complex behaviors to be designed de novo. While highly specific, these high-order circuits are usually sequence constrained, making their adaptability toward biological targets challenging. Here, we devise a new strategy called indirect associative strand displacement to decouple sequence constraints between miRNA inputs and de novo strand displacement circuits. By splitting circuit inputs into their toehold and branch migration regions and controlling their association through a docking strand, we demonstrate how any miRNA sequence can be interfaced with synthetic DNA circuits, including catalytic hairpin assembly and a four-input classifier.

Mapping Research on miRNAs in Cancer: A Global DataAnalysis and Bibliometric Profiling Analysis

miRNAs biomarkers are emerging as an essential part of clinical oncology. Their oncogenic and tumour suppressor properties playing a role in malignancy has generated interest in their potential for use in disease prognosis. While several studies on miRNA have been carried out across the globe, evaluating the clinical implications of miRNAs in cancer diagnosis and prognosis research has currently not been attempted. A study delineating the area of miRNA research, including the topics presently being focused on, the seminal papers in this field, and the direction of research interest, does not exist. This study aims to conduct a large-scale, global data analysis and bibliometric profiling analysis of studies to evaluate the research output of clinical implications of miRNAs in cancer diagnosis and prognosis listed in the SCOPUS database. A systematic search strategy was followed to identify and extract all relevant studies, subsequently analysed to generate a bibliometric map. SPSS software (version 27) was used to calculate bibliometric indicators or parameters for analysis, such as year and country of affiliation with leading authors, journals, and institutions. It is also used to analyse annual research outputs, including total citations and the number of times it has been cited with productive nations and H-index. The number of global research articles retrieved for miRNA-Cancer research over the study period 2003 to 2019 was 18,636. Between 2012 and 2019, the growth rate of global publications is six times (n = 15,959; 90.71 percent articles) that of 2003 to 2011. (2704; 9.29 per cent articles). China published the most publications in the field of miRNA in cancer (n = 7782; 41%), while the United States had the most citations (n = 327,538; 48%) during the time span. Of these journals, Oncotarget has the highest percentage of article publications. The journal Cancer Research had the most citations (n = 41,876), with 6.20 per cent (n = 41,876). This study revealed a wide variety of journals in which miRNA-Cancer research are published; these bibliometric parameters exhibit crucial clinical information on performance assessment of research productivity and quality of research output. Therefore, this study provides a helpful reference for clinical oncologists, cancer scientists, policy decision-makers and clinical data researchers.

Role of miRNA-145, 148, and 185 and Stem Cells in Prostate Cancer

MicroRNAs (miRNAs) are small non-coding RNA molecules that play a role in cancer linked to the regulation of important cellular processes and pathways involving tumorigenesis, cell proliferation, differentiation, and apoptosis. A lot of human miRNA sequences have been identified which are linked to cancer pathogenesis. MicroRNAs, in prostate cancer (PC), play a relevant role as biomarkers, show a specific profile, and have been used as therapeutic targets. Prostate cancer (PC) is the most frequently diagnosed cancer in men. Clinical diagnoses among the gold standards for PC diagnosis and monitoring are prostate-specific antigen (PSA) testing, digital rectal examination, and prostate needle biopsies. PSA screening still has a large grey area of patients, which leads to overdiagnosis. Therefore, new biomarkers are needed to improve existing diagnostic tools. The miRNA expression profiles from tumour versus normal tissues are helpful and exhibit significant differences not only between cancerous and non-cancerous tissues, but also between different cancer types and subtypes. In this review, we focus on the role of miRNAs-145, 148, and 185 and their correlation with stem cells in prostate cancer pathogenesis. MiR-145, by modulating multiple oncogenes, regulates different cellular processes in PC, which are involved in the transition from localised to metastatic disease. MiR-148 is downregulated in high-grade tumours, suggesting that the miR-148-3 family might act as tumour suppressors in PC as a potential biomarker for detecting this disease. MiR-185 regulation is still unclear in being able to regulate tumour processes in PC. Nevertheless, other authors confirm the role of this miRNA as a tumour suppressor, suggesting its potential use as a suitable biomarker in disease prognosis. These three miRNAs are all involved in the regulation of prostate cancer stem cell behaviour (PCSCs). Within this contest, PCSCs are often involved in the onset of chemo-resistance in PC, therefore strategies for targeting this subset of cells are strongly required to control the disease. Hence, the relationship between these two players is interesting and important in prostate cancer pathogenesis and in PCSC stemness regulation, in the attempt to pave the way for novel therapeutic targets in prostate cancer.

Exosome-Transmitted miR-128 Targets CCL18 to Inhibit the Proliferation and Metastasis of Urothelial Carcinoma

Objective: To investigate the regulatory function of exosome-transmitted miR-128 and chemokine (C-C motif) ligand 18 (CCL18) on urothelial carcinomas (UCs).

Methods: Tumor tissues, paracancerous tissues, and serum were collected from 20 patients with UCs (diagnosed at Beijing Friendship Hospital, Capital Medical University). CCL18 was detected by immunohistochemistry and ELISA. PCR was used to measure the expression levels of CCL18 and mir-183, miR-128, mir-33a in UCs. We acquired exosomes from mesenchymal stem cells and synthesized exosomes overexpressing miR-128 (HMSC-128-EV). The effects of miR-128 on the migration and invasion abilities, apoptosis and epithelial-mesenchymal transition of BUC T24 cells were investigated by co-culturing HMSC-128-EV. The therapeutic potential of miR-128 on disease models was explored by injecting HMSC-128-EV into nude mice.

Results: The expression of CCL18 in UCs was significantly higher than that in normal tissues (p < 0.05), and the serum level of CCL18 in patients with UC was significantly increased compared with those in healthy controls (p < 0.05). CCL18 overexpression or downregulation enhanced or suppressed the proliferation, migration and invasion of BUC T24 cells, resectively (p < 0.05). The exosome-transmitted miR-128 can inhibit cell proliferation (p < 0.05), invasion (p < 0.05), and migration (p < 0.05) in UCs, and these effects can be reversed by CCL18. In terms of apoptosis, miR-128 was able to promote the occurrence of BUC T24 apoptosis (p < 0.05), which can also be reversed by CCL18. In addition, miR-128 can inhibit the proliferation (p < 0.05) and metastasis (p < 0.05) of UCs in nude mice.

Conclusion: The miR-128 inhibits the proliferation, invasion, migration of UCs, and promotes its apoptosis by regulating CCL18 secretion.

A Brief Introduction to Current Cancer Gene Therapy

Gene therapy has started in the late 1980s as novel, clinically applicable therapeutic option. It revolutionized the treatment of genetic diseases with the initial intent to repair or replace defective genes. Gene therapy has been adapted for treatment of malignant diseases to improve the outcome of cancer patients. In fact, cancer gene therapy has rapidly gained great interest and evolved into a research field with highest proportion of research activities in gene therapy. In this context, cancer gene therapy has long entered translation into clinical trials and therefore more than two-thirds of all gene therapy trials worldwide are aiming at the treatment of cancer disease using different therapeutic strategies. During the decades in cancer gene therapy, tremendous knowledge has accumulated. This led to significant improvements in vector design, transgene repertoire, more targeted interventions, use of novel gene therapeutic technologies such as CRISPR/Cas, sleeping beauty vectors, and development of effective cancer immunogene therapies. In this chapter, a brief overview of current key developments in cancer gene therapy is provided to gain insights into the recent directions in research as well as in clinical application of cancer gene therapy.

Metal-Organic Framework Nanoparticles Power DNAzyme Logic Circuits for Aberrant MicroRNA Imaging

At the molecular level, a large number of studies exist on the use of dynamic DNA molecular circuits for disease diagnosis and biomedicine. However, how to design programmable molecular circuit devices to autonomously and accurately diagnose multiple low-abundance biomolecules in complex cellular environments remains a challenge. Here, we constructed DNAzyme logic circuits for the analysis and imaging of multiple microRNAs in living cells using Cu/ZIF-8 NPs as a nanocarrier of the logic gate modules and the Cu²⁺ cofactor of the Cu²⁺-dependent DNAzyme. The logic gate modules of the logic operation system were adsorbed on the surface of Cu/ZIF-8 NPs via electrostatic interaction. After internalization, pH-responsive Cu/ZIF-8 NPs could efficiently release the logic gate modules and Cu²⁺, which allowed us to realize multiple logic computations initiated by endogenous miRNA, including one YES logic gate and two binary logic gates (OR and AND) in different living cells. Cu²⁺-DNAzyme logic circuits could quickly respond to multiple endogenous miRNAs in the complex cell environment, which also provided a new research method for the application of DNA biocomputing circuits in living cells.

Non-coding RNAs in melanoma: Biological functions and potential clinical applications

Malignant melanoma (MM) is a malignant tumor that originates from melanocytes and has a high mortality rate. Therefore, early diagnosis and treatment are very important for survival. So far, the exact molecular mechanism leading to the occurrence of melanoma, especially the molecular metastatic mechanism, remains largely unknown. Non-coding RNAs (ncRNAs), such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNA (circRNAs), have been investigated and found to play vital roles in regulating tumor occurrence and development, including melanoma. In this review, we summarize the progress of recent research on the effects of ncRNAs on melanoma and attempt to elucidate the role of ncRNAs as molecular markers or potential targets that will provide promising application perspectives on melanoma.

The Role of microRNAs in Development of Colitis-Associated Colorectal Cancer

Colorectal cancer (CRC) is the third most deadly cancer worldwide, and inflammatory bowel disease (IBD) is one of the critical factors in CRC carcinogenesis. IBD is responsible for an unphysiological and sustained chronic inflammation environment favoring the transformation. MicroRNAs (miRNAs) belong to a class of highly conserved short single-stranded segments (18-25 nucleotides) non-coding RNA and have been extensively discussed in both CRC and IBD. However, the role of miRNAs in the development of colitis-associated CRC (CAC) is less clear. The aim of this review is to summarize the major upregulated (miR-18a, miR-19a, miR-21, miR-31, miR-155 and miR-214) and downregulated (miR-124, miR-193a-3p and miR-139-5p) miRNAs in CAC, and their roles in genes' expression modulation in chronic colonic-inflammation-induced carcinogenesis, including programmed cell-death pathways. These miRNAs dysregulation could be applied for early CAC diagnosis, to predict therapy efficacy and for precision treatment.

miR-378a-5p inhibits the proliferation of colorectal cancer cells by downregulating CDK1

BACKGROUND

MicroRNAs (miRNAs) play an important role in tumor occurrence. The role of miR-378a-5p and CDK1 in colorectal cancer (CRC) was investigated in this study.

METHODS

Investigation of TCGA database and the detection of miR-378a-5p expression in colorectal cancer pathological tissues and colorectal cancer cell lines were undertaken by using qRT-PCR. We performed cell function experiments (CCK-8 assay, EdU assay, colony formation assay, wound healing assay, transwell assay, cell apoptosis assessment, and cell cycle assessment) and nude mouse tumor formation experiments to evaluate the effects of miR-378a-5p on proliferation, metastasis, and invasion to explore the role of miR-378a-5p in vivo and in vitro. Next, through TCGA database, immunohistochemical staining of pathological tissues, and cell function experiments, the role of the target gene CDK1 of miR-378a-5p was verified by database prediction, and dual luciferase reporter gene experiments in colorectal cancer cells were performed. Finally, whether upregulation of CDK1 restores the inhibitory effect of overexpression of miR-378a-5p on the proliferation of CRC cells was studied by overexpression of CDK1.

RESULTS

Bioinformatic analysis showed significant downregulation of miR-378a-5p levels in colorectal cancer (CRC). Cell function experiments and tumor xenograft mouse models confirmed the low expression of miR-378a-5p within CRC tissues, which indicated the tumor suppressive role of miR-378a-5p in CRC. To better explore the regulation of miR-378a-5p in CRC, we predicted and validated cell cycle-dependent protein kinase 1 (CDK1) as the miR-378a-5p target gene and observed that miR-378a-5p suppressed CRC cell proliferation by targeting CDK1.

CONCLUSION

The results of this study help to elucidate the mechanism by which miR-378a-5p can be used as a tumor marker to inhibit the growth of colorectal cancer and CDK1, which is related to the prognosis of colorectal cancer patients. MiR-378a-5p inhibits CRC cell proliferation by suppressing CDK1 expression, which may become a possible therapeutic target for treatment of CRC.

TRIM25 contributes to the malignancy of acute myeloid leukemia and is negatively regulated by microRNA-137

Background

Acute myeloid leukemia (AML) is a ubiquitous malignancy that occurs in the hematological system. Tripartite motif-containing 25 (TRIM25) has been found to be involved in various carcinomas comprising AML. However, the function and underlying causative role of TRIM25 in AML are still obscure.

Methods and materials

Quantitative real-time polymerase chain reaction (qPCR) was used for assaying TRIM25 and miR-137 expression in AML samples and cells. CCK-8 assay, Calcein-acetoxymethylester/propidium iodide staining, and Transwell assay were adopted to assay cell proliferation, invasion, and migration. Dual-luciferase reporter experiment was used for analyzing the interaction of TRIM25 with miR-137. Western blot was used for assaying protein expression levels.

Results

This study confirmed that TRIM25 expression was upregulated in AML samples and cell lines, whereas miR-137 expression was downregulated. Overexpression of TRIM25 significantly contributed to AML cell’s proliferation, invasion, and migration, whereas knockdown exerted the opposite effect. In addition, TRIM25 was a downstream target of miR-137 in AML cells and negatively modulated by miR-137.

Conclusion

TRIM25 was targeted and regulated by miR-137, exerted a carcinogenic function in AML, and could be used as a latent biomarker and a treatment target for AML.

Identification of core miRNAs and regulatory pathways in breast cancer by integrated bioinformatics analysis

Breast cancer (BC) ranks first among malignancies in the female population due to its complicated pathological progression and poor prognosis. Hence, the aim of the present study was to identify potential molecular prognostic biomarkers able to predict the prognosis of BC patients. We integrated two microRNA (miRNA) expression microarrays and three gene microarrays related to BC from the NCBI Gene Expression Comprehensive (GEO) database to screen for differentially expressed miRNAs and identify their regulatory networks. The Kaplan-Meier plotter online analysis tool was used to assess the overall survival value of miRNAs expression in BC patients. The LinkedOmics online tool was used to analyze genes correlated with miRNAs expression. To clarify the upstream regulation mechanism of genes, we used ChIP-Atlas to identify and screen for transcription factors and visually verify them using the Integrative Genomics Viewer. To further analyze the downstream regulatory mechanism of miRNA in BC, we verified differentially expressed genes (DEGs) correlated to miRNAs in three GEO gene microarrays and the gene set predicted by miRWalk. The open access Metascape program allowed analysis of Gene Ontology (GO) processes, KEGG pathways and GO enrichment was performed on the DEGs. To further identify hub genes, Cytoscape software and its plug-in were applied to construct protein-protein interaction networks. In the present study, several possible molecules and related pathways related to miR-483 were identified by bioinformatics analysis. These molecules and pathways might represent key mechanisms involved in BC progression and development. This work provides a novel view and insight in the pathogenesis, treatment and prognosis for BC.

The role of microRNAs in ovarian function and the transition toward novel therapeutic strategies in fertility preservation: from bench to future clinical application

BACKGROUND

New therapeutic approaches in oncology have converted cancer from a certain death sentence to a chronic disease. However, there are still challenges to be overcome regarding the off-target toxicity of many of these treatments. Oncological therapies can lead to future infertility in women. Given this negative impact on long-term quality of life, fertility preservation is highly recommended. While gamete and ovarian tissue cryopreservation are the usual methods offered, new pharmacological-based options aiming to reduce ovarian damage during oncological treatment are very attractive. In this vein, advances in the field of transcriptomics and epigenomics have brought small noncoding RNAs, called microRNAs (miRNAs), into the spotlight in oncology. MicroRNAs also play a key role in follicle development as regulators of follicular growth, atresia and steroidogenesis. They are also involved in DNA damage repair responses and they can themselves be modulated during chemotherapy. For these reasons, miRNAs may be an interesting target to develop new protective therapies during oncological treatment. This review summarizes the physiological role of miRNAs in reproduction. Considering recently developed strategies based on miRNA therapy in oncology, we highlight their potential interest as a target in fertility preservation and propose future strategies to make the transition from bench to clinic.

OBJECTIVE AND RATIONALE

How can miRNA therapeutic approaches be used to develop new adjuvant protective therapies to reduce the ovarian damage caused by cytotoxic oncological treatments?

SEARCH METHODS

A systematic search of English language literature using PubMed and Google Scholar databases was performed through to 2019 describing the role of miRNAs in the ovary and their use for diagnosis and targeted therapy in oncology. Personal data illustrate miRNA therapeutic strategies to target the gonads and reduce chemotherapy-induced follicular damage.

OUTCOMES

This review outlines the importance of miRNAs as gene regulators and emphasizes the fact that insights in oncology can inspire new adjuvant strategies in the field of onco-fertility. Recent improvements in nanotechnology offer the opportunity for drug development using next-generation miRNA-nanocarriers.

WIDER IMPLICATIONS

Although there are still some barriers regarding the immunogenicity and toxicity of these treatments and there is still room for improvement concerning the specific delivery of miRNAs into the ovaries, we believe that, in the future, miRNAs can be developed as powerful and non-invasive tools for fertility preservation.

Long noncoding RNA PWRN1 is lowly expressed in osteosarcoma and modulates cancer proliferation and migration by targeting hsa-miR-214-5p

BACKGROUND

We examined the expression pattern, clinical relevance, and molecular mechanisms of lncRNA PWRN1 in human osteosarcoma.

METHODS

qPCR was used to measure PWRN1 expressions in cell lines and tumor samples osteosarcoma. The correlations between PWRN1 and cancer patients' clinicopathological properties and survival were examined. PWRN1 was ectopically overexpressed in MG-63 and 143B cells to assess its function on cancer cell proliferation, cisplatin chemoresistance, and in vivo xenotransplant growth. The ceRNA candidate of PWRN1, miR-214-5p was examined in osteosarcoma cells. In addition, miR-214-5p and PWRN1 were double-overexpressed in osteosarcoma cells to investigate the regulatory role of epigenetic axis PWRN1/miR-214-5p in osteosarcoma.

RESULTS

We found that PWRN1 was downregulated in both osteosarcoma cells and human tumors. PWRN1 downregulation was correlated with advanced stage, metastasis, and low survival rate in cancer patients. PWRN1 overexpression in osteosarcoma cells significantly inhibited their proliferation, cisplatin chemoresistance, and in vivo growth. In addition, we demonstrated that PWRN1 directly bound miR-214-5p and suppressed its expression in osteosarcoma cells. Furthermore, we showed that miR-214-5p overexpression reversed the anti-cancer effects of PWRN1 on osteosarcoma cell proliferation and cisplatin chemoresistance.

CONCLUSION

Our data provide new insights into the epigenetic axis of PWRN1/miR-214-5p in regulating osteosarcoma progression and chemoresistance. PWRN1 may also be a biomarker to predicting cancer patients' poor prognosis and novel pharmaceutical targets for personalized medicine.

The diagnostic value of miR-92a, -143, and -145 expression levels in patients with colorectal adenocarcinoma from Romania

MicroRNAs (miRNAs) refers to a small, short non-coding RNA of endogenous class. They have shown to have an increasingly altered expression in many types of cancer, including colorectal cancer (CRC).In the present study, miRNA TaqManMGB and qRT-PCR was used to quantify the expression and clinical significance of 3 mature human miRNA in 82 pairs of colorectal adenocarcinoma tissues and normal adjacent tissue samples (NATS) collected from patients of the south-east part of Romania. Differences between CRC and NATS were analyzed using Wilcoxon test, while correlations between miRNAs expression levels and clinicopathological features were examined using non-parametric tests. In addition, the ability of selected miRNAs to function as biomarkers and, as potential indicators in CRC prognosis was also examined.When the miRNA expression was compared in CRC related NATS, miR-143, and miR-145 were significantly underexpressed (4.99 ± -1.02 vs -5.66 ± -1.66, P < .001; -4.85 ± -0.59 vs -9.27 ± -1.51, P < .001, respectively), while the pattern of miR-92a was significantly overexpressed (-5.55 ± -2.83 vs -4.92 ± -2.44, P < .001). Moreover, the expression levels of selected miRNAs were identified to be correlated with gradual increases in fold change expression with the depth of tumor invasion, lymph node invasion, and maximal increases with distant metastasis. Furthermore, the receiver operating characteristic analysis demonstrated that potential diagnostic of miR-143, miR-145, and miR-92a in discriminating CRC from NATS, with the area under the curve of 0.74, 0.85, and 0.84 respectively. The Kaplan-Meier and the log-rank test showed that a high level of miR-92a and low levels of miR-143 and miR-145 predicted poor survival rate in our cohorts.In conclusion, we can summarize that miR-145 and miR-143 are decreased, while miR-92 is increased in CRC compared to NATS, and associated with different stages of CRC pathogenesis. Thus, the expression of selected miRNAs can represent potential diagnostic and prognostic tools in patients with CRC from Romania.

miR-454 suppresses the proliferation and invasion of ovarian cancer by targeting E2F6

Background

The aberrant expression of microRNA-454 (miR-454) has been confirmed to be involved in the development of cancers. However, the functional role of miR-454 in the progression of ovarian cancer remains unclear.

Methods

The expression of miR-454 in ovarian cancer cells and serum of ovarian cancer patients was detected by RT-PCR. CCK8, colony formation, transwell, and flow cytometry assays were conducted to assess the effects of miR-454 on ovarian cancer cell proliferation, migration, invasion, and apoptosis, respectively. Dual-luciferase reporter assay was used to confirm the targeting relationship between miR-454 and E2F6. The expression pattern of E2F6 in ovarian cancer tissues was detected using immunohistochemistry (IHC) assay. The relative expression of related proteins was examined using western blot analysis.

Results

miR-454 was markedly down-regulated by hypoxia in ovarian cancer cells. Compared with normal samples, the expression of miR-454 was up-regulated in the serum of ovarian cancer patients, and correlated with the clinicopathological stages of ovarian cancer. Next, we found that miR-454 overexpression inhibited the proliferation, migration and invasion of OVCAR3 and SKOV3 cells, as well as promoted apoptosis. In addition, the Akt/mTOR and Wnt/β-catenin signaling pathway were inhibited by miR-454 in ovarian cancer cells. Mechanically, bioinformatic analysis and dual-luciferase reporter assay confirmed that E2F6 was a direct target of miR-454 and negatively regulated by miR-454 in ovarian cancer cells. Moreover, IHC analysis showed that E2F6 was highly expressed in ovarian cancer tissues. Finally, we found that the increasing cell proliferation and migration triggered by E2F6 overexpression were abolished by miR-454 overexpression.

Conclusion

Taken together, these results highlight the role of miR-454 as a tumor suppressor in ovarian cancer cells by targeting E2F6, indicating that miR-454 may be a potential diagnostic biomarker and therapeutic target for ovarian cancer.

Construction and Analysis of a ceRNA Network Reveals Potential Prognostic Markers in Colorectal Cancer

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide and is derived from an accumulation of genetic and epigenetic changes. This study explored potential prognostic markers in CRC via the construction and in-depth analysis of a competing endogenous RNA (ceRNA) network, which was generated through a three-step process. First, we screened candidate hub genes in CRC as the primary gene markers to survey their related regulatory non-coding RNAs, miRNAs. Second, the interacting miRNAs were used to search for associated lncRNAs. Thus, candidate RNAs were first constructed into ceRNA networks based on close associations with miRNAs. Further analysis at the isomiR level was also performed for each miRNA locus to understand the detailed expression patterns of the multiple variants. Finally, RNAs were performed an in-depth analysis of expression correlations, which contributed to further screening and validation of potential RNAs with close correlations to each other. Using this approach, nine hub genes, 13 related miRNAs, and 29 candidate lncRNAs were collected and used to construct the ceRNA network. Further in-depth analysis identified the MFAP5-miR-200b-3p-AC005154.6 axis as a potential prognostic marker in CRC. MFAP5 and miR-200b-3p have previously been reported to play important roles in tumorigenesis. These RNAs showed potential prognostic values, and the combination of them may have more sensitivity than using them alone. In conclusion, MFAP5, miR-200b-3p, and AC005154.6 may have potential prognostic value in CRC and may provide a prognostic reference for this patient population.

Long Non-Coding RNA NNT-AS1 Contributes to Cisplatin Resistance via miR-1236-3p/ATG7 Axis in Lung Cancer Cells

Purpose

Lung cancer is one of the most prevailing human cancers worldwide. Emerging evidence implies that long non-coding RNA nicotinamide nucleotide transhydrogenase-antisense RNA1 (NNT-AS1) is implicated in the tumorigenesis of lung cancer. Herein, we aimed to expose the impact of NNT-AS1 on the drug resistance of lung cancer.

Methods

Levels of NNT-AS1, microRNA (miR)-1236-3p and autophagy-related gene 7 (ATG7) were evaluated using quantitative real-time polymerase chain reaction (qRT-PCR) assay. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was implemented to detect cell proliferation and the half maximal inhibitory concentration (IC₅₀) of cisplatin (DDP) in vitro. Moreover, flow cytometry was performed to assess cell apoptosis. Cell migration and invasion were examined utilizing transwell assay in lung cancer cells. Besides, levels of ATG7 and cell behavior-related proteins were determined via Western blot. Dual-luciferase reporter assay was administrated to identify the interaction between miR-1236-3p and NNT-AS1 or ATG7. The biological role of NNT-AS1 in DDP resistance of lung cancer was examined by xenograft tumor model in vivo.

Results

NNT-AS1 and ATG7 were upregulated, whereas miR-1236-3p was curbed in lung cancer tissues and in with or without DDP-resistant cell lines. NNT-AS1 detection significantly constrained cell growth, metastasis, and the IC₅₀ of DDP in A549/DDP and H522/DDP cells. Interestingly, the influence of miR-1236-3p mimic on DDP resistance was overturned via NNT-AS1 upregulation in vitro. Reintroduction of miR-1236-3p inhibitor relieved the effect of ATG7 silencing on DDP sensitivity in A549/DDP and H522/DDP cells. Importantly, NNT-AS1 was a sponge of miR-1236-3p to separate ATG7. Besides, NNT-AS1 silencing enhanced DDP sensitivity of lung cancer in vivo.

Conclusion

NNT-AS1/miR-1236-3p/ATG7 axis regulated DDP resistance in lung cancer cells and might supply a probable target and prognostic marker in lung cancer treatment.

MiR-217 Inhibits M2-Like Macrophage Polarization by Suppressing Secretion of Interleukin-6 in Ovarian Cancer

Ovarian cancer is one of the most deadly cancers with rapid proliferation and poor prognosis among patients. Therapies focusing on regulation of tumor immunity and microenvironments are developing. MiR-217 was dysregulated in cancer progress and plays important roles in tumorigenesis and metastasis. However, the role of miR-217 in regulation of macrophage polarization and its underlying molecular mechanism remain unclear. The expression of miR-217 in ovarian cancerous tissues and cell lines were assessed by qRT-PCR. And we detected the staining of CD86 and CD206 via flow-cytometry and the levels of Arg-1 and CCR2 by western-blot in order to evaluate M2 macrophage polarization. The targeting regulation of miR-217 on pro-inflammatory factor IL-6 was assessed by dual-luciferase reporter assay and western-blot. ELISA assay was used to evaluate the secretion of IL-6 and IL-10 of cells. MiR-217 was found to be downregulated in ovarian cancerous tissues and cell lines. This downregulation correlated with an increased expression of the IL-6, Arg-1, CCR2, and CD206 gene. The overexpression of miR-217 in SKOV3 cells can inhibit the polarization of macrophages towards an M2-like phenotype. We also found that IL-6 was validated to induce M2 macrophage polarization and its secretion in SKOV-3 cells was inhibited by miR-217 directly. Moreover, we revealed that miR-217 suppressed M2 macrophage polarization partly thought JAK/STAT3 signal pathway. Taken together, these findings indicate that miR-217 inhibits tumor-induced M2 macrophage polarization through targeting of IL-6 and regulation JAK3/STAT3 signaling pathway, which may provide a potential therapeutic target for treating ovarian cancer.

miR-489-3p/SIX1 Axis Regulates Melanoma Proliferation and Glycolytic Potential

Sine oculis homeobox 1 (SIX1), a key transcription factor for regulating aerobic glycolysis, participates in the occurrence of various cancer types. However, the role of SIX1 in melanoma and the upstream regulating mechanisms of SIX1 remain to be further investigated. MicroRNAs (miRNAs) have emerged as key regulators in tumorigenesis and progression. Here, we show that miR-489-3p suppresses SIX1 expression by directly targeting its 3′ untranslated region (3′ UTR) in melanoma cells. miR-489-3p suppressed melanoma cell proliferation, migration, and invasion through inhibition of SIX1. Mechanistically, by targeting SIX1, miR-489-3p dampens glycolysis, with decreased glucose uptake, lactate production, ATP generation, and extracellular acidification rate (ECAR), as well as an increased oxygen consumption rate (OCR). Importantly, glycolysis regulated by the miR-489-3p/SIX1 axis is critical for its regulation of melanoma growth and metastasis both in vitro and in vivo. In melanoma patients, miR-489-3p expression is negatively correlated with SIX1 expression. In addition, patients who had increased glucose uptake in tumors and with metastasis assessed by positron emission tomography (PET) scans showed decreased miR-489-3p expression and increased expression of SIX1. Collectively, our study demonstrates the importance of the miR-489-3p/SIX1 axis in melanoma, which can be a potential and a promising therapeutic target in melanoma.

Resveratrol chemosensitizes adriamycin-resistant breast cancer cells by modulating miR-122-5p

Breast cancer is one of the major malignancies threatening women's health worldwide, and chemotherapy tolerance has become a severe limitation of clinical treatment. Recent findings have revealed that resveratrol, as a dietary agent with antitumour activity, could prevent cancer progression by regulating microRNAs (miRNAs). Additionally, dysregulated miRNAs have been found to contribute significantly to chemoresistance by an increasing number of studies. In this study, experiments were designed to study the functional role of resveratrol in MCF-7 cells (low-invasive breast cancer) in chemosensitivity to adriamycin and to determine the targeted miRNAs of resveratrol and their key target proteins linked to cell activity. We demonstrated that in resveratrol-induced chemosensitivity, cell cycle and apoptosis were arrested in adriamycin-resistant breast cancer cells after modulation of the critical suppresser, miR-122-5p. Further miRNA modulation with miR-122-5p mimics or miR-122-5p inhibitors indicated a major effect of miR-122-5p on the regulation of key antiapoptotic proteins (B-cell lymphoma 2 [Bcl-2]) and cyclin-dependent kinases (CDK2, CDK4, and CDK6) in drug-resistant breast cancer cells in response to resveratrol. In conclusion, our results indicate that resveratrol acts as a potential inducer to enhance the chemosensitivity of breast cancer and also suggest that miR-122-5p is involved in the pathway of cell-cycle arrest by targeting Bcl-2 and CDKs.

Analysis of 8q24.21 miRNA cluster expression and copy number variation in gastric cancer

Aim: To analyze gene expression and copy number of five miRNAs (miR-1204, miR-1205, miR-1206, miR-1207 and miR-1208) localized in this chromosome region in gastric cancer (GC). Materials & methods: 65 paired neoplastic and non-neoplastic specimens collected from GC patients and 20 non-neoplastic gastric tissues from cancer-free individuals were included in this study. The expression levels of the five miRNAs were accessed by real time qPCR and were correlated. Results: MiR-1207-3p, miR-1205, miR-1207-5p and miR-1208 were upregulated in approximately 50% of GC tumors in relation to those of adjacent non-neoplastic tissues. MiR-1205 expression was associated with gain of gene copies and was upregulated in adjacent non-neoplastic samples relative to external controls. Conclusion: The coexpression of the 8q24 miRNAs indicated the role of miR-1205 in the initiation of gastric cancer development.

NCKAP1 improves patient outcome and inhibits cell growth by enhancing Rb1/p53 activation in hepatocellular carcinoma

In our previous report, we identified miR-34c-3p as an independent factor contributing to the carcinogenesis of hepatocellular carcinoma (HCC) by targeting NCK Associated Protein 1 (NCKAP1). NCKAP1 has been known to promote the malignancy of cancer cells by disrupting the structural stability of WAS protein family member 1 (WASF1) and is correlated with poor prognosis of patients in several cancer types. Our results, however, show that NCKAP1 is correlated with a favorable outcome in HCC patients. The underlying mechanism of this contradictory phenomenon is unknown. The current study was designed to explore the mechanism of NCKAP1 in HCC. As a result, clinicopathological correlations and results from in vivo and in vitro models indicated that NCKAP1 was a tumor suppressor gene. Cell cycle analysis suggested that NCKAP1 inhibit cells from entering G2/M phase. Western blot analysis showed that WASF1 was barely expressed in HCC cell lines compared to that of breast cancer cell lines, which serve as positive controls. Furthermore, Rb1 and p53 expression was upregulated in cell lines overexpressing NCKAP1. Expression of several cell cycle regulating proteins also varied in the HCC cell lines. In conclusion, although previous studies have identified NCKAP1 as a cell invasion promoter by binding to WASF1, we found that NCKAP1 is a tumor suppress gene that modulates the cell cycle of HCC cell lines by targeting Rb1/p53 regulation.

Phenylboronic acid-functionalized polyamidoamine-mediated miR-34a delivery for the treatment of gastric cancer

In the present research, a tumor-targeted gene carrier, PPP, was constructed through the modification of phenylboronic acid onto the surface of a polyamidoamine dendrimer, and then miR-34a delivery was employed as a model to evaluate its anti-tumor efficacy.

Co-Delivery Nanosystems for Cancer Treatment: A Review

Massive data available on cancer therapy more than ever lead our mind to the general concept that there is no perfect treatment for cancer. Indeed, the biological complexity of this disease is too excessive to be treated by a single therapeutic approach. Current delivery systems containing a specific drug or gene have their particular opportunities and restrictions. It is worth noting that a considerable number of studies suggest that single- drug delivery systems result in insufficient suppression of cancer growth. Therefore, one of the main ideas of co-delivery system designing is to enhance the intended response or to achieve the synergistic/combined effect compared to the single drug strategy. This review focuses on various strategies for co-delivery of therapeutic agents in the treatment of cancer. The primary approaches within the script are categorized into co-delivery of conventional chemotherapeutics, gene-based molecules, and plant-derived materials. Each one is explained in examples with the recent researches. In the end, a brief summary is provided to conclude the gist of the review.

Overexpressing lncRNA SNHG16 inhibited HCC proliferation and chemoresistance by functionally sponging hsa-miR-93

Background

Long noncoding RNAs (lncRNAs) have been identified as prognostic biomarkers and functional regulators in human cancers. The present study aimed to determine the expressions and functions of an lncRNA, Small Nucleolar RNA Host Gene 16 (SNHG16), in hepatocellular carcinoma (HCC).

Patients and methods

SNHG16 expressions were tested by quantitative real-time PCR (qRT-PCR) in HCC cell lines, as well as 43 pairs of HCC tissues and pair-matched healthy hepatic tissues. It was overexpressed in Hep3B and HuH7 cells. The effects of SNHG16 overexpression in HCC in vitro proliferation, 5-fluorouracil (5-FU) chemoresistance, and in vivo tumor growth were tested. A potential microRNA (miRNA) sponge target of SNHG16, hsa-miR-93, was tested by luciferase reporter assay and qRT-PCR. In addition, hsa-miR-93 was upregulated in SNHG16-overexpressed HCC cells to examine its effect on SNHG16-mediated cancer cell functional regulation in HCC.

Results

SNHG16 levels were markedly downregulated in both HCC cell lines and HCC tissues. Lentivirus-mediated SNHG16 overexpression inhibited HCC cell proliferation, 5-FU chemoresistance, and in vivo tumor growth. Hsa-miR-93 was confirmed to be directly sponging on SNHG16. Its upregulation in HCC cells reversed SNHG16 overexpression and induced tumor-suppressing effects in HCC cells.

Conclusion

Our data demonstrate that SNHG16 plays a critical role in HCC development via functionally sponging hsa-miR-93.

MicroRNA-1270 modulates papillary thyroid cancer cell development by regulating SCAI

PURPOSE

We intended to evaluate expression and mechanisms of human microRNA 1270 (hsa-miR-1270) in papillary thyroid cancer (PTC).

METHODS

In PTC cell lines and human PTC tumors, hsa-miR-1270 expressions were evaluated by qRT-PCR. Hsa-miR-1270 was downregulated in TPC1 and K1 cells via lentiviral transduction. Its effects on PTC cancer cell proliferation, migration and in vivo transplantation were assessed, respectively. Potential targeting of hsa-miR-1270 on downstream gene, Suppressor Of Cancer Cell Invasion (SCAI), was assessed. In hsa-miR-1270-downregulated PTC cells, SCAI was further downregulated to examine its associating role in hsa-miR-1270-mediated regulation on cancer cell proliferation and migration.

RESULTS

Hsa-miR-1270 was aberrantly upregulated in PTC cell lines and human PTC tumors. In TPC1 and K1 cells, lentivirus-mediated hsa-miR-1270 downregulation suppressed cancer cell proliferation, migration and in vivo transplantation. Hsa-miR-1270 binds SCAI and inversely regulated SCAI gene expression in PTC cells. SCAI downregulation removed the suppressing effects of hsa-miR-1270 downregulation in human PTC cells.

CONCLUSION

Hsa-miR-1270 downregulation may suppress human PTC cell development both in vitro and in vivo. The regulatory mechanism of hsa-miR-1270 in PTC may be primarily associated with SCAI.

A curcumin-loaded polymeric micelle as a carrier of a microRNA-21 antisense-oligonucleotide for enhanced anti-tumor effects in a glioblastoma animal model

A glioblastoma is a common primary brain tumor that expresses microRNA-21 (miR-21), which inhibits the expression of pro-apoptotic genes such as phosphatase and tensin homologue (PTEN) and programmed cell death 4 (PDCD4). Therefore, an antisense-oligonucleotide against miR-21 (miR21ASO) could have therapeutic effects for glioblastomas. In this study, curcumin was loaded into deoxycholic acid-conjugated polyethylenimine (DP) micelles. The curcumin-loaded DP micelle (DP-Cur) was evaluated as a carrier for the combined delivery of curcumin and miR21ASO. Gel retardation and heparin competition assays showed that DP-Cur formed stable complexes with miR21ASO. The anti-tumor effects of the combined delivery of curcumin and miR21ASO were evaluated in C6 glioblastoma cells. In vitro transfection showed that DP-Cur had an miR21ASO delivery efficiency similar to that of polyethylenimine (25 kDa, PEI25k) and DP. In the C6 cells, the delivery of miR21ASO using DP-Cur effectively reduced the miR21 level. The miR21ASO/DP-Cur complex induced apoptosis more effectively than the single delivery of curcumin or miR21ASO. The therapeutic effect of the miR21ASO/DP-Cur complex was also evaluated in an intracranial glioblastoma animal model. The miR21ASO/DP-Cur complex reduced the tumor volume more effectively than single therapy of curcumin or miR21ASO. Immunohistochemistry showed that PDCD4 and PTEN were induced in the miR21ASO/DP and miR21ASO/DP-Cur complex groups. Therefore, DP-Cur is an efficient carrier of miR21ASO and the combined delivery of miR21ASO and curcumin may be useful in the development of combination therapy for glioblastoma.

Comprehensive and integrative analysis identifies microRNA-106 as a novel non-invasive biomarker for detection of gastric cancer

Background

Recently, accumulating evidences have revealed that microRNA-106 (miR-106) may serve as a non-invasive and cost-effective biomarker in gastric cancer (GC) detection. However, inconsistent results have prevented its application to clinical practice.

Methods

As a result of this, a comprehensive meta-analysis was conducted to evaluate the diagnostic performance of miR-106 alone and miR-106-related combination markers for GC detection. Meanwhile, an integrative bioinformatics analysis was performed to explore the function of miR-106 at the systems biology level.

Results

The results in our work showed that sensitivity of 0.71 (95% CI 0.65–0.76) and specificity of 0.82 (0.72–0.88), with the under area AUC (area under the curve) value of 0.80 (0.76–0.83) for miR-106 alone. Prospectively, miR-106-related combination markers improved the combined sensitivity, specificity and AUC, describing the discriminatory ability of 0.78 (0.65–0.87), 0.83 (0.77–0.89) and 0.88 (0.85–0.90) in the present analysis. Furthermore, targets of miR-106 were obtained and enriched by gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis, revealing their associations with the occurrence and development of GC. Hub genes and significant modules were identified from the protein–protein interaction networks constructed by miR-106 targets and found closely associated with the initiation and progression of GC again.

Conclusions

Our comprehensive and integrative analysis revealed that miR-106 may be suitable as a diagnostic biomarker for GC while microRNA combination biomarkers may provide a new alternative for clinical application. However, it is necessary to conduct large-scale population-based studies and biological experiments to further investigate the diagnostic value of miR-106.

MicroRNA-139-5p Inhibits Cell Proliferation and Invasion by Targeting RHO-Associated Coiled-Coil-Containing Protein Kinase 2 in Ovarian Cancer

Increasing evidence indicates that the dysregulation of microRNAs is associated with the development and progression of various cancers. MicroRNA-139-5p (miR-139-5p) has been reported to have a tumor suppressive role in many types of cancers. The role of miR-139-5p in ovarian cancer (OC) is poorly understood. The purpose of the present study was to explore the expression of miR-139-5p and its function in OC. The results showed that miR-139-5p expression was markedly downregulated in OC tissues and cell lines. In addition, underexpression of miR-139-5p was significantly associated with FIGO stage, lymph mode metastasis, and poor overall survival of OC patients. Functional analyses indicated that overexpression of miR-139-5p significantly inhibited proliferation, colony formation, migration, and invasion of OC cells. Rho-associated coiled-coil-containing protein kinase 2 (ROCK2) was identified as a direct target of miR-139-5p using luciferase reporter assays, qualitative real-time reverse transcriptase PCR (qRT-PCR), and Western blot. In addition, ROCK2 expression was upregulated and was inversely correlated with miR-139-5p levels in OC tissues. Rescue experiments showed that overexpression of ROCK2 effectively reversed the inhibitory effect of OC cells induced by miR-139-5p. Most interestingly, in vivo studies indicated that miR-139-5p markedly suppressed the growth of tumors by repressing ROCK2 expression in nude mice. Taken together, these findings demonstrated that miR-139-5p plays an important tumor suppressor role in OC by directly binding to ROCK2, providing a novel target for the molecular treatment of OC.

MicroRNA Regulation of Telomerase Reverse Transcriptase (TERT): Micro Machines Pull Strings of Papier-Mâché Puppets

Substantial fraction of high-quality information is continuously being added into the existing pool of knowledge related to the biology of telomeres. Based on the insights gleaned from decades of research, it is clear that chromosomal stability needs a highly controlled and dynamic balance of DNA gain and loss in each terminal tract of telomeric repeats. Telomeres are formed by tandem repeats of TTAGGG sequences, which are gradually lost with each round of division of the cells. Targeted inhibition of telomerase to effectively induce apoptosis in cancer cells has attracted tremendous attention and overwhelmingly increasingly list of telomerase inhibitors truthfully advocates pharmacological significance of telomerase. Telomerase reverse transcriptase (TERT) is a multi-talented and catalytically active component of the telomerase-associated protein machinery. Different proteins of telomerase-associated machinery work in a synchronized and orchestrated manner to ensure proper maintenance of telomeric length of chromosomes. Rapidly emerging scientific findings about regulation of TERT by microRNAs has revolutionized our understanding related to the biology of telomeres and telomerase. In this review, we have comprehensively discussed how different miRNAs regulate TERT in different cancers. Use of miRNA-based therapeutics against TERT in different cancers needs detailed research in preclinical models for effective translation of laboratory findings to clinically effective therapeutics.

Covalent Strategies for Targeting Messenger and Non-Coding RNAs: An Updated Review on siRNA, miRNA and antimiR Conjugates

Oligonucleotide-based therapy has become an alternative to classical approaches in the search of novel therapeutics involving gene-related diseases. Several mechanisms have been described in which demonstrate the pivotal role of oligonucleotide for modulating gene expression. Antisense oligonucleotides (ASOs) and more recently siRNAs and miRNAs have made important contributions either in reducing aberrant protein levels by sequence-specific targeting messenger RNAs (mRNAs) or restoring the anomalous levels of non-coding RNAs (ncRNAs) that are involved in a good number of diseases including cancer. In addition to formulation approaches which have contributed to accelerate the presence of ASOs, siRNAs and miRNAs in clinical trials; the covalent linkage between non-viral vectors and nucleic acids has also added value and opened new perspectives to the development of promising nucleic acid-based therapeutics. This review article is mainly focused on the strategies carried out for covalently modifying siRNA and miRNA molecules. Examples involving cell-penetrating peptides (CPPs), carbohydrates, polymers, lipids and aptamers are discussed for the synthesis of siRNA conjugates whereas in the case of miRNA-based drugs, this review article makes special emphasis in using antagomiRs, locked nucleic acids (LNAs), peptide nucleic acids (PNAs) as well as nanoparticles. The biomedical applications of siRNA and miRNA conjugates are also discussed.

Machine Learning Approaches Toward Building Predictive Models for Small Molecule Modulators of miRNA and Its Utility in Virtual Screening of Molecular Databases

The ubiquitous role of microRNAs (miRNAs) in a number of pathological processes has suggested that they could act as potential drug targets. RNA-binding small molecules offer an attractive means for modulating miRNA function. The availability of bioassay data sets for a variety of biological assays and molecules in public domain provides a new opportunity toward utilizing them to create models and further utilize them for in silico virtual screening approaches to prioritize or assign potential functions for small molecules. Here, we describe a computational strategy based on machine learning for creation of predictive models from high-throughput biological screens for virtual screening of small molecules with the potential to inhibit microRNAs. Such models could be potentially used for computational prioritization of small molecules before performing high-throughput biological assay.

Clinical Impact of microRNAs Associated With Cancer Stem Cells as a Prognostic Factor in Ovarian Carcinoma

Background: Ovarian carcinoma is a highly lethal gynecological malignancy due to its frequent relapses and adoption of chemoresistance. To develop new biomarkers for disease progression in ovarian carcinoma, CSCs, which are considered to contribute to disease relapse and metastasis, were isolated from human ovarian carcinoma tissues, and differentially expressed microRNAs (miRNAs) in CSCs were identified and assessed the clinical implication of expression of these miRNAs.

Methods: Primary cancer cells derived from human ovarian carcinomas were cultured and spheroid-forming cells (SFCs) were isolated. Profiles of miRNA expression in CSC-like SFCs were identified by miRNA microarray and the results were validated by quantitative real-time RT-PCR (qRT-PCR). We also assessed the correlations between miRNA expression levels and clinicopathological parameters in ovarian carcinomas.

Results: Five miRNAs (miR-5703, miR-630, miR-1246, miR-424-5p, and miR-320b) were significantly dysregulated in CSC-like SFCs compared with primary cancer cells. The qRT-PCR showed that miR-5703 and miR-1246 expression was significantly higher in ovarian cancer cells than in normal control cells, whereas the miR-424-5p level was significantly lower. Decreased expression of miR-424-5p was significantly associated with distant metastasis in high stage (stage IIII & IV) carcinomas (35.5% vs. 72.2%, respectively, p=0.013)

Conclusion: Taken together, miR-5703, miR-630, miR-1246, miR-424-5p, and miR-320b are useful markers for enriching ovarian CSCs. Decreased expression of miR-424-5p in ovarian carcinoma might be a putative biomarker for distant metastasis in ovarian carcinoma.

miR106b regulates retinoblastoma Y79 cells through Runx3

MicroRNAs are increasingly recognized as important regulators of cancer. The aim of the present study was to investigate the role of miR-106b in the regulation of Y79 retinoblastoma. Y79 cells were transfected with antisense oligonucleotides (ASO) against miR-106b (ASO-miR-106b) or ASO-control. After transfection, the levels of miR-106b were monitored with real-time PCR (RT-PCR). The effects of ASO-miR-106b transfection on cell viability was evaluated by Cell Counting Kit-8 (CCK-8) analysis at 24, 48 and 72 h after transfection. Subsequently, the cells were stained with Annexin V-FITC and propidium iodide (PI) and subjected to flow cytometry to assess cell apoptosis. Transwell assay was used to analyze cell migration. Changes in Runt-related transcription factor 3 (Runx3) mRNA and proteins levels were also evaluated. miR-106b was downregulated by ASO-miR-106b at 48 and 72 h after transfection, accompanied by a decrease in cell viability and proliferation, as well as an increase in cell apoptosis. Transwell analysis indicated that cells treated with ASO-miR-106b exhibited significantly lower cell migratory abilities. The mRNA and protein level of Runx3 were upregulated after transfection. These results demonstrated that suppression of miR-106b inhibited Y79 cell proliferation and migration. The upregulation of Runx3 after miR-106b suppression ascertained that Runx3 is a tumor-suppressor in retinoblastoma and is a target of miR-106b.

A DNA-Fueled and Catalytic Molecule Machine Lights Up Trace Under-Expressed MicroRNAs in Living Cells

The detection of specific intracellular microRNAs (miRNAs) in living cells can potentially provide insight into the causal mechanism of cancer metastasis and invasion. However, because of the characteristic nature of miRNAs in terms of small sizes, low abundance, and similarity among family members, it is a great challenge to monitor miRNAs in living cells, especially those with much lower expression levels. In this work, we describe the establishment of a DNA-fueled and catalytic molecule machinery in cell signal amplification approach for monitoring trace and under-expressed miRNAs in living cells. The presence of the target miRNA releases the hairpin sequences from the dsDNA (containing the fluorescence resonance energy transfer (FRET) pair-labeled and unfolded hairpin sequences)-conjugated gold nanoparticles (dsDNA-AuNPs), and the DNA fuel strands assist the recycling of the target miRNA sequences via two cascaded strand displacement reactions, leading to the operation of the molecular machine in a catalytic fashion and the release of many hairpin sequences. As a result, the liberated hairpin sequences restore the folded hairpin structures and bring the FRET pair into close proximity to generate significantly amplified signals for detecting trace miRNA targets. Besides, the dsDNA-AuNP nanoprobes have good nuclease stability and show low cytotoxicity to cells, and the application of such a molecular system for monitoring trace and under-expressed miRNAs in living cells has also been demonstrated. With the advantages of in cell signal amplification and reduced background noise, the developed method thus offers new opportunities for detecting various trace intracellular miRNA species.

Biological effects and clinical characteristics of microRNA-106a in human colorectal cancer

MicroRNAs serve important roles in various diseases, particularly cancer. microRNA-106a (miR-106a) exhibits abnormal expression and oncogenic activity in carcinogenesis. The clinical significance of the abnormal expression of miR-106a in colorectal cancer is poorly understood. In the present study, miR-106a expression from colorectal cancer tissues was quantified using the reverse transcription-quantitative polymerase chain reaction. The overexpression or knockdown of miR-106a was performed by transfection with microRNA mimic or inhibitor in human colorectal carcinoma HCT116 cells. The overexpression of miR-106a promoted viability and inhibited apoptosis in colorectal cancer cells. The association between miR-106a expression and clinicopathological factors was analyzed, and it was identified that miR-106a exhibited significantly increased expression in adenocarcinoma tissues compared with in mucinous carcinoma tissues, and the expression of miR-106a was identified to be associated with the depth of invasion and differentiation. The expression of miR-106a in plasma was also determined and it was identified that increased expression of miR-106a, as a characteristic of patients with colorectal cancer, may be distinguished from that of other patients by digitization of the areas under the receiver operating characteristic curves. These data suggested that miR-106a is a potential biomarker in the diagnosis of colorectal carcinoma. However, the underlying molecular mechanism of miR-106a-promoted viability and inhibition of apoptosis requires further investigation.

Epigallocatechin-3-gallate Modulates MicroRNA Expression Profiles in Human Nasopharyngeal Carcinoma CNE2 Cells

Background:

Epigallocatechin-3-gallate (EGCG) has exhibited antitumor properties in several types of cancers, including nasopharyngeal carcinoma (NPC), but the molecular mechanisms underlying this function remain incompletely understood. The aim of the present study was to characterize the global impact of EGCG on the expression of microRNAs (miRNAs) in NPC cells.

Methods:

Using microarray analysis, the alterations of miRNA expression profiles were investigated in EGCG-treated CNE2 cells. Furthermore, the target genes and signaling pathways regulated by EGCG-specific miRNAs were identified using target prediction program and gene ontology analysis.

Results:

A total of 14 miRNAs exhibited >2-fold expression changes in a dose-dependent manner after treatment with 20 μmol/L and 40 μmol/L EGCG. Totally 43, 49, and 52 target genes from these differentially expressed miRNAs were associated with the apoptosis, cell cycle regulation, and cell proliferation, respectively. A total of 66 signaling pathways, primarily involved in cancer development and lipid and glucose metabolism, were shown to be regulated by EGCG-specific miRNAs.

Conclusion:

EGCG induces considerable alterations of miRNA expression profiles in CNE2 cells, which provides mechanistic insights into cellular responses and antitumor activity mediated by EGCG.

miRNA-144 induces microglial autophagy and inflammation following intracerebral hemorrhage

Autophagic activation mediated inflammation contributes to brain injury of intracerebral hemorrhage (ICH). MiRNAs play a key role in inflammation, which negatively and posttranscriptionally regulate gene expression and function. Modulating the mTOR signal, a central regulator of autophagy, could be of great significance for ICH. However, the specific of miRNA is unknown. In the current study, we detected the miRNA-144 expression, autophagic activity and inflammation of microglia in ICH. We also knocked down endogenous miRNA-144 to regulate autophagy and inflammation in ICH. In addition, we assessed the neurological damge in ICH mice. We found that ICH promoted miRNA-144 expression but downregulated mTOR expression. In addition, upregulation of mTOR attenuated microglial autophagy and inflammation in ICH. Furthermore, downregulation of miRNA-144 also inhibited inflammation, brain edema and improved neurological functions in ICH mice. Taken together, our findings suggested that miRNA-144 was a crucial regulator of autophagy via regulation of mTOR, and represented a promising therapeutical strategy for ICH.