MiRNA-based therapeutic intervention of cancer

Bacteria extracellular vesicle as nanopharmaceuticals for versatile biomedical potential

Bacteria extracellular vesicles (BEVs), characterized as the lipid bilayer membrane-surrounded nanoparticles filled with molecular cargo from parent cells, play fundamental roles in the bacteria growth and pathogenesis, as well as facilitating essential interaction between bacteria and host systems. Notably, benefiting from their unique biological functions, BEVs hold great promise as novel nanopharmaceuticals for diverse biomedical potential, attracting significant interest from both industry and academia. Typically, BEVs are evaluated as promising drug delivery platforms, on account of their intrinsic cell-targeting capability, ease of versatile cargo engineering, and capability to penetrate physiological barriers. Moreover, attributing to considerable intrinsic immunogenicity, BEVs are able to interact with the host immune system to boost immunotherapy as the novel nanovaccine against a wide range of diseases. Towards these significant directions, in this review, we elucidate the nature of BEVs and their role in activating host immune response for a better understanding of BEV-based nanopharmaceuticals' development. Additionally, we also systematically summarize recent advances in BEVs for achieving the target delivery of genetic material, therapeutic agents, and functional materials. Furthermore, vaccination strategies using BEVs are carefully covered, illustrating their flexible therapeutic potential in combating bacterial infections, viral infections, and cancer. Finally, the current hurdles and further outlook of these BEV-based nanopharmaceuticals will also be provided.

MiR-136-5p in cancer: Roles, mechanisms, and chemotherapy resistance

MicroRNAs (miRNAs) have emerged as important regulators of gene expression, and the deregulation of their activity has been linked to the onset and progression of a variety of human malignancies. Among these miRNAs, miR-136-5p has attracted significant attention due to its diverse roles in cancer biology. Mostly, miR-136-5p is downregulated in malignancies. It could inhibit viability, proliferation, migration, invasion and promote apoptosis of tumor cells. This review article provides a comprehensive overview of the current understanding of miR-136-5p in different sorts of human cancers: genital tumors, head and neck tumors, tumors from the digestive and urinary systems, skin cancers, neurologic tumors, pulmonary neoplasms and other cancers by discussing its molecular mechanisms, functional roles, and impact in chemotherapies. In conclusion, miR-136-5p could be a promising new biomarker and potential clinical therapeutic target.

Non-coding RNAs in leukemia drug resistance: new perspectives on molecular mechanisms and signaling pathways

Like almost all cancer types, timely diagnosis is needed for leukemias to be effectively cured. Drug efflux, attenuated drug uptake, altered drug metabolism, and epigenetic alterations are just several of the key mechanisms by which drug resistance develops. All of these mechanisms are orchestrated by up- and downregulators, in which non-coding RNAs (ncRNAs) do not encode specific proteins in most cases; albeit, some of them have been found to exhibit the potential for protein-coding. Notwithstanding, ncRNAs are chiefly known for their contribution to the regulation of physiological processes, as well as the pathological ones, such as cell proliferation, apoptosis, and immune responses. Specifically, in the case of leukemia chemo-resistance, ncRNAs have been recognized to be responsible for modulating the initiation and progression of drug resistance. Herein, we comprehensively reviewed the role of ncRNAs, specifically its effect on molecular mechanisms and signaling pathways, in the development of leukemia drug resistance.

Targeting vimentin: a multifaceted approach to combatting cancer metastasis and drug resistance

This comprehensive review explores vimentin as a pivotal therapeutic target in cancer treatment, with a primary focus on mitigating metastasis and overcoming drug resistance. Vimentin, a key player in cancer progression, is intricately involved in processes such as epithelial-to-mesenchymal transition (EMT) and resistance mechanisms to standard cancer therapies. The review delves into diverse vimentin inhibition strategies. Precision tools, including antibodies and nanobodies, selectively neutralize vimentin's pro-tumorigenic effects. DNA and RNA aptamers disrupt vimentin-associated signaling pathways through their adaptable binding properties. Innovative approaches, such as vimentin-targeted vaccines and microRNAs (miRNAs), harness the immune system and post-transcriptional regulation to combat vimentin-expressing cancer cells. By dissecting vimentin inhibition strategies across these categories, this review provides a comprehensive overview of anti-vimentin therapeutics in cancer treatment. It underscores the growing recognition of vimentin as a pivotal therapeutic target in cancer and presents a diverse array of inhibitors, including antibodies, nanobodies, DNA and RNA aptamers, vaccines, and miRNAs. These multifaceted approaches hold substantial promise for tackling metastasis and overcoming drug resistance, collectively presenting new avenues for enhanced cancer therapy.

The crucial role of fascin-1 in the pathogenesis, metastasis, and chemotherapeutic resistance of breast cancer

Breast cancer (BC) is the most common type of cancer in women to be diagnosed, and it is also the second leading cause of cancer death in women globally. It is the disease that causes the most life years adjusted for disability lost among women, making it a serious worldwide health issue. Understanding and interpreting carcinogenesis and metastatic pathways is critical for curing malignancy. Fascin-1 was recognized as an actin-bundling protein with parallel, rigid bundles as a result of the cross-linking of F-actin microfilaments. Increasing levels of fascin-1 have been associated with bad prognostic profiles, aggressiveness of clinical courses, and poor survival outcomes in a variety of human malignancies. Cancer cells that overexpress fascin-1 have higher capabilities for proliferation, invasion, migration, and metastasis. Fascin-1 is being considered as a potential target for therapy as well as a potential biomarker for diagnostics in a variety of cancer types. This review aims to provide an overview of the FSCN1 gene and its protein structure, elucidate its physiological and pathological roles, and throw light on its involvement in the initiation, development, and chemotherapeutic resistance of BC.

Recent insights into the functions and mechanisms of antisense RNA: emerging applications in cancer therapy and precision medicine

The antisense RNA molecule is a unique DNA transcript consisting of 19-23 nucleotides, characterized by its complementary nature to mRNA. These antisense RNAs play a crucial role in regulating gene expression at various stages, including replication, transcription, and translation. Additionally, artificial antisense RNAs have demonstrated their ability to effectively modulate gene expression in host cells. Consequently, there has been a substantial increase in research dedicated to investigating the roles of antisense RNAs. These molecules have been found to be influential in various cellular processes, such as X-chromosome inactivation and imprinted silencing in healthy cells. However, it is important to recognize that in cancer cells; aberrantly expressed antisense RNAs can trigger the epigenetic silencing of tumor suppressor genes. Moreover, the presence of deletion-induced aberrant antisense RNAs can lead to the development of diseases through epigenetic silencing. One area of drug development worth mentioning is antisense oligonucleotides (ASOs), and a prime example of an oncogenic trans-acting long noncoding RNA (lncRNA) is HOTAIR (HOX transcript antisense RNA). NATs (noncoding antisense transcripts) are dysregulated in many cancers, and researchers are just beginning to unravel their roles as crucial regulators of cancer's hallmarks, as well as their potential for cancer therapy. In this review, we summarize the emerging roles and mechanisms of antisense RNA and explore their application in cancer therapy.

Molecular imprinting of miR-559 on a peptide-immobilized poly L-DOPA/silica core-shell and in vitro investigating its effects on HER2-positive breast cancer cells

In a significant percentage of breast cancers, increased expression of the HER2 receptor is seen and is associated with the spread and worsening of the disease. This research aims to investigate the effect of miR-559 (which targets HER2 mRNA) on SKBR3 breast cancer cells and the possibility of their effective delivery with polymeric nanoparticles and tumor-targeting peptides. L-DOPA monomers were polymerized on the surface of silica nanoparticles in the presence of miR-559 (as a molecular template for molecular imprinting) then an anti-HER2 peptide coupled to the surface of these polymeric nanocomposites (miR-NC-NL2), and the effects of this construct against a HER2-positive breast cancer cells (SKBR3 cells) investigated in vitro conditions. The results showed that miR-NC-NL2 is selective for HER2-positive cells and delivers the miR-559 to them in a targeted manner. miR-NC-NL2 decreased the proliferation of SKBR3 cells and reduced the expression and production of HER2 protein in these cells. Effective and targeted delivery of miR-559 to HER2-positive cancer cells by the miR-NC-NL2 promises the therapeutic potential of this nascent structure based on its inhibitory effect on cancer growth and progression. Of course, animal experiments require a better understanding of this structure's anti-tumor effects.

Targeted miR-34a delivery with PD1 displayed bacterial outer membrane vesicles-coated zeolitic imidazolate framework nanoparticles for enhanced tumor therapy

MicroRNA (miRNA) has been widely used as an effective gene drug for tumor therapy, but its chemical instability limited its therapeutic application in vivo. In this research, we fabricate an efficient miRNA nano-delivery system using zeolitic imidazolate framework-8 (ZIF-8) coated with bacterial outer membrane vesicles (OMVs), aimed for cancer treatment. The acid-sensitive ZIF-8 core enables this system to encapsulate miRNA and release them from lysosome quickly and efficiently in the target cells. The OMVs engineered to display programmed death receptor 1 (PD1) on the surface provides a specific tumor-targeting capability. Using a murine breast cancer model, we show that this system has high miRNA delivery efficiency and accurate tumor targeting. Moreover, the miR-34a payloads in carriers can further synergize with immune activation and checkpoint inhibition triggered by OMV-PD1 to enhance tumor therapeutic efficacy. Overall, this biomimetic nano-delivery platform provides a powerful tool for the intracellular delivery of miRNA and has great potential in RNA-based cancer therapeutic applications.

Salivary micro RNAs as biomarkers for oropharyngeal cancer

BACKGROUND

Despite the rising incidence, particularly of the human papillomavirus (HPV)-associated fraction of oropharyngeal cancer (OPC), there are no early detection methods for OPC. Considering the close association between saliva and head and neck cancers, this study was designed to investigate salivary micro RNA (miRNAs) associated with OPC, especially focusing on HPV-positive OPC.

METHODS

Saliva was collected from OPC patients at diagnosis and patients were clinically followed up ≤5 years. Salivary small RNA isolated from HPV-positive OPC patients (N = 6), and HPV-positive (N = 4) and negative controls (N = 6) were analysed by next-generation sequencing to identify dysregulated miRNAs. Discovered miRNAs were validated by quantitative PCR using two different assays in a separate cohort of patients (OPC = 91, controls = 92). The relative expression was calculated considering SNORD-96A as the normalizer. Candidate miRNAs with diagnostic and prognostic potential were evaluated by generalized logistic regression.

RESULTS

A panel consisting of nine miRNAs was identified to have the best diagnostic performance to discriminate HPV-positive OPC from HPV-positive controls (AUC- validation-1 = 94.8%, validation-2 = 98%). Further, a panel consisting of six miRNAs were identified to discriminate OPC from controls regardless of the HPV status (AUC- validation-1 = 77.2%, validation-2 = 86.7%). In addition, the downregulation of hsa-miR-7-5p was significantly associated with poor overall survival of OPC patients (HR = 0.638). A panel consisting of nine miRNAs were identified for the prediction of the overall survival of the OPC patients (log-rank test-p = 0.0008).

CONCLUSION

This study highlights that salivary miRNAs can play an essential role in the detection and prognostication of OPC.

An emphasis on the interaction of signaling pathways highlights the role of miRNAs in the etiology and treatment resistance of gastric cancer

Gastric cancer (GC) is 4th in incidence and mortality rates globally. Several genetic and epigenetic factors, including microRNAs (miRNAs), affect its initiation and progression. miRNAs are short chains of nucleic acids that can regulate several cellular processes by controlling their gene expression. So, dysregulation of miRNAs expressions is associated with GC initiation, progression, invasion capacity, apoptosis evasions, angiogenesis, promotion and EMT enhancement. Of important pathways in GC and controlled by miRNAs are Wnt/β-catenin signaling, HMGA2/mTOR/P-gp, PI3K/AKT/c-Myc, VEGFR and TGFb signaling. Hence, this review was conducted to review an updated view of the role of miRNAs in GC pathogenesis and their modulatory effects on responses to different GC treatment modalities.

The potential role of miRNAs in the pathogenesis of salivary gland cancer - A Focus on signaling pathways interplay

Salivary gland cancer (SGC) is immensely heterogeneous, both in terms of its physical manifestation and its aggressiveness. Developing a novel diagnostic and prognostic detection method based on the noninvasive profiling of microribonucleic acids (miRs) could be a goal for the clinical management of these specific malignancies, sparing the patients' valuable time. miRs are promising candidates as prognostic biomarkers and therapeutic targets or factors that can advance the therapy of SGC due to their ability to posttranscriptionally regulate the expression of various genes involved in cell proliferation, differentiation, cell cycle, apoptosis, invasion, and angiogenesis. Depending on their biological function, many miRs may contribute to the development of SGC. Therefore, this article serves as an accelerated study guide for SGC and the biogenesis of miRs. Here, we shall list the miRs whose function in SGC pathogenesis has recently been determined with an emphasis on their potential applications as therapeutic targets. We will also offer a synopsis of the current state of knowledge about oncogenic and tumor suppressor miRs in relation to SGC.

The interplay of signaling pathways and miRNAs in the pathogenesis and targeted therapy of esophageal cancer

Globally, esophageal cancer (EC) is the 6th leading cause of cancer-related deaths and the second deadliest gastrointestinal cancer. Multiple genetic and epigenetic factors, such as microRNAs (miRNAs), influence its onset and progression. miRNAs are short nucleic acid molecules that can regulate multiple cellular processes by regulating gene expression. Therefore, EC initiation, progression, apoptosis evasions, invasion capacity, promotion, angiogenesis, and epithelial-mesenchymal transition (EMT) enhancement are associated with miRNA expression dysregulation. Wnt/-catenin signaling, Mammalian target of rapamycin (mTOR)/P-gp, phosphoinositide-3-kinase (PI3K)/AKT/c-Myc, epidermal growth factor receptor (EGFR), and transforming growth factor (TGF)-β signaling are crucial pathways in EC that are controlled by miRNAs. This review was conducted to provide an up-to-date assessment of the role of microRNAs in EC pathogenesis and their modulatory effects on responses to various EC treatment modalities.

miRNAs role in cervical cancer pathogenesis and targeted therapy: Signaling pathways interplay

Cervical cancer (CC) is the primary cause of cancer deaths in underdeveloped countries. The persistence of infection with high-risk human papillomavirus (HPV) is a significant contributor to the development of CC. However, few women with morphologic HPV infection develop invasive illnesses, suggesting other mechanisms contribute to cervical carcinogenesis. MicroRNAs (miRNAs, miRs) are small chain nucleic acids that can regulate wide networks of cellular events. They can inhibit or degrade their target protein-encoding genes. They had the power to regulate CC's invasion, pathophysiology, angiogenesis, apoptosis, proliferation, and cell cycle phases. Further research is required, even though novel methods have been developed for employing miRNAs in the diagnosis, and treatment of CC. We'll go through some of the new findings about miRNAs and their function in CC below. The function of miRNAs in the development of CC and its treatment is one of these. Clinical uses of miRNAs in the analysis, prediction, and management of CC are also covered.

MicroRNAs Improve Cancer Treatment Outcomes Through Personalized Medicine

MicroRNAs (miRNAs) are short non-coding RNAs that repress or degrade mRNA targets to downregulate genes. In cancer occurrence, the expression of miRNAs is altered. Depending on the involvement of a certain miRNA in the pathogenetic growth of a tumor, It may be up or downregulated. The "oncogenic" action of miRNAs corresponds with upregulation, which leads to tumor proliferation and spread meanwhile the miRNAs that have been downregulated bring tumorsuppressive outcomes. Oncogenes and tumor suppressor genes are among the genes whose expression is under their control, demonstrating that classifying them solely as oncogenes or tumor suppressor genes alone is not only hindering but also incorrect. Apart from basic tumors, miRNAs may be found in nearly all human fluids and can be used for cancer diagnosis as well as clinical outcome prognostics and better response to treatment strategies. The overall variance of these tiny noncoding RNAs influences patient-specific pharmacokinetics and pharmacodynamics of anti-cancer medicines, driving a growing demand for personalized medicine. By now, microRNAs from tumor biopsies or blood are being widely investigated as substantial biomarkers for cancer in time diagnosis, prognosis, and, progression. With the rise of COVID-19, this paper also attempts to study recent research on miRNAs involved with deaths in lung cancer COVID patients. With the discovery of single nucleotide polymorphisms, personalized treatment via microRNAs has lately become a reality. The present review article describes the highlights of recent knowledge of miRNAs in various cancers, with a focus on miRNA translational applications as innovative potential diagnostic and prognostic indicators that expand person-to-person therapy options.

RNA-binding protein PUM2 promotes T-cell acute lymphoblastic leukemia via competitively binding to RBM5 3'UTR with miR-28-5p

OBJECTIVE

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematologic malignancy, and T-ALL patients are prone to early disease relapse and suffer from poor outcomes. The crucial function of RNA-binding proteins (RBPs) has been reported in the progression of cancers by regulating the expression of transcripts. This study aimed to reveal the role and molecular regulatory mechanism of RBP Pumilio2 (PUM2) in T-ALL.

METHODS

The expression of genes was detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. The viability, proliferation, and apoptosis of T-ALL cells were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, 5-ethynyl-2'-deoxyuridine, and flow cytometry analysis. Luciferase reporter, RNA pulldown, and RNA immunoprecipitation assays were performed to confirm the binding of PUM2 to RBM5. The combination between RNA-binding motif protein 5 (RBM5) and microRNA (miR)-28-5p was validated using luciferase reporter assay.

RESULTS

Our data revealed that PUM2 was highly expressed in T-ALL blood samples and cell lines. PUM2 knockdown suppressed the proliferation but accelerated the apoptosis of T-ALL cells in vitro. Additionally, RBM5 exhibited a low expression level in T-ALL samples and cells. PUM2 negatively regulated RBM5 via targeting its 3'untranslated region (3'UTR). Moreover, PUM2 competitively bound to RBM5 3'UTR with miR-28-5p. Rescue experiments showed that RBM5 knockdown reversed the anti-tumor effects mediated by PUM2 knockdown in T-ALL cells.

CONCLUSION

PUM2 plays as a novel oncogenic RBP in T-ALL by competitively binding to RBM5 mRNA with miR-28-5p.

Monocytes educated by cancer-associated fibroblasts secrete exosomal miR-181a to activate AKT signaling in breast cancer cells

BACKGROUND

Cancer-associated fibroblasts (CAFs), one of the major components of the tumor stroma, contribute to an immunosuppressive tumor microenvironment (TME) through the induction and functional polarization of protumoral macrophages. We have herein investigated the contribution of CAFs to monocyte recruitment and macrophage polarization. We also sought to identify a possible paracrine mechanism by which CAF-educated monocytes affect breast cancer (BC) cell progression.

METHODS

Monocytes were educated by primary CAFs and normal fibroblast (NF); the phenotypic alterations of CAF- or NF-educated monocytes were measured by flow cytometry. Exosomes isolated from the cultured conditioned media of the educated monocytes were characterized. An in vivo experiment using a subcutaneous transplantation tumor model in athymic nude mice was conducted to uncover the effect of exosomes derived from CAF- or NF-educated monocytes on breast tumor growth. Gain- and loss-of-function experiments were performed to explore the role of miR-181a in BC progression with the involvement of the AKT signaling pathway. Western blotting, enzyme-linked immunosorbent assay, RT-qPCR, flow cytometry staining, migration assay, immunohistochemical staining, and bioinformatics analysis were performed to reveal the underlying mechanisms.

RESULTS

We illustrated that primary CAFs recruited monocytes and established pro-tumoral M2 macrophages. CAF may also differentiate human monocyte THP-1 cells into anti-inflammatory M2 macrophages. Besides, we revealed that CAFs increased reactive oxygen species (ROS) generation in THP-1 monocytes, as differentiating into M2 macrophages requires a level of ROS for proper polarization. Importantly, T-cell proliferation was suppressed by CAF-educated monocytes and their exosomes, resulting in an immunosuppressive TME. Interestingly, CAF-activated, polarized monocytes lost their tumoricidal abilities, and their derived exosomes promoted BC cell proliferation and migration. In turn, CAF-educated monocyte exosomes exhibited a significant promoting effect on BC tumorigenicity in vivo. Of clinical significance, we observed that up-regulation of circulating miR-181a in BC was positively correlated with tumor aggressiveness and found a high level of this miRNA in CAF-educated monocytes and their exosomes. We further clarified that the pro-oncogenic effect of CAF-educated monocytes may depend in part on the exosomal transfer of miR-181a through modulating the PTEN/Akt signaling axis in BC cells.

CONCLUSIONS

Our findings established a connection between tumor stromal communication and tumor progression and demonstrated an inductive function for CAF-educated monocytes in BC cell progression. We also proposed a supporting model in which exosomal transfer of miR-181a from CAF-educated monocytes activates AKT signaling by regulating PTEN in BC cells.

Bacteria-derived outer membrane vesicles engineered with over-expressed pre-miRNA as delivery nanocarriers for cancer therapy

Outer membrane vesicles (OMVs) of Escherichia coli as nanoscale spherical vesicles have been recently used in cancer therapy as drug carriers. However, most of them need complicated methods to load cargos. Herein, we proposed an inexpensive and potentially mass-produced method for the preparation of OMV engineered with over-expressed pre-miRNA. In this work, we found that OMV can be released and inherit over-expressed tRNA^{Lys-pre-miRNA} from mother E. coli that directly used for the tumor therapy. The eukaryotic cells infection experiments revealed that the over-expressed pre-miRNA inside OMV could be released and processed into mature miRNAs with the aid of the camouflage of "tRNA scaffold". Moreover, the group in vivo treated with targeted OMV^{tRNA-pre-miR-126} obviously inhibited the expression of target oncogenic CXCR4, and significantly restrain the proliferation of breast cancer tissues. Together, these findings indicated that the OMV-based platform is a versatile and powerful strategy for personalized tumor therapy directly and specificity.

Altered RNome expression in Murine Gastrocnemius Muscle following Exposure to Jararhagin, a Metalloproteinase from Bothrops jararaca Venom

Small RNAs (sRNAs) and microRNAs (miRNAs) are small endogenous noncoding single-stranded RNAs that regulate gene expression in eukaryotes. Experiments in mice and humans have revealed that a typical small RNA can affect the expression of a wide range of genes, implying that small RNAs function as global regulators. Here, we used small RNA deep sequencing to investigate how jararhagin, a metalloproteinase toxin produced from the venom of Bothrops jararaca, affected mmu-miRNAs expression in mice 2 hours (Jar 2hrs) and 24 hours (Jar 24hrs) after injection compared to PBS control. The findings revealed that seven mmu-miRNAs were substantially differentially expressed (p value (p (Corr) cut-off 0.05, fold change ≥ 2) at 2 hrs after jararhagin exposure and that the majority of them were upregulated when compared to PBS. In contrast to these findings, a comparison of Jar 24hrs vs. PBS 24hrs demonstrated that the majority of identified mmu-miRNAs were downregulated. Furthermore, the studies demonstrated that mmu-miRNAs can target the expression of several genes involved in the MAPK signaling pathway. The steady antithetical regulation of mmu-miRNAs may correlate with the expression of genes that trigger apoptosis via MAPK in the early stages, and this effect intensifies with time. The findings expand our understanding of the effects of jararhagin on local tissue lesions at the molecular level.

miR-21-5p serves as a promoter in renal cell carcinoma progression through ARHGAP24 downregulation

Renal cell carcinoma (RCC) is a highly recurrent aggressive tumor. This study works for the regulation of miR-21-5p on RCC cell functions and novel ideas for therapies of RCC. Isoform expression quantification data were offered by The Cancer Genome Atlas Kidney Renal Clear Cell Carcinoma (TCGA-KIRC) to investigate differentially expressed miRNAs. The way miR-21-5p works on biological functions of RCC was examined with MTT and Transwell assays. The downstream targets of miR-21-5p were predicted using bioinformatics analysis. The binding of two researched objects was verified by the dual-luciferase method. TCGA data manifested a considerably high level of miR-21-5p in RCC tissue, while ARHGAP24 was significantly lowly expressed. miR-21-5p bound ARHGAP24 and stimulated RCC cell functions, whereas ARHGAP24 mimic could reverse such promotion. This work observed miR-21-5p, a stimulator in RCC, and it deteriorated this cancer via repressing its downstream target gene ARHGAP24 expression.

MiR-206 conjugated gold nanoparticle based targeted therapy in breast cancer cells

MicroRNAs (miRNAs) are single-stranded, non-coding, 19–25 nucleotide RNA molecules that have been observed to be dysregulated in many diseases including cancer. miRNAs have been known to play an important role in cellular proliferation, differentiation, migration, apoptosis, survival, and morphogenesis. Breast cancer is heterogeneous in nature and contributed extensively to the increased mortality rate. miRNA can either be tumor-suppressive or oncogenic in nature. The level of expression of miRNA changes according to the subtypes of cancer and the mutation responsible for different cancers. miRNA mimicry or inhibition are emerging possible therapies to maintain the level of miRNA inside the cells. In order to have proper miRNA mimicry, the major hurdle is to deliver the miRNA mimics at the site of tumor. Metallic nanoparticles with modified surface can be used to solve the problem of miRNA delivery. MiR-206 is reported to be down-regulated in Luminal-A type of breast cancer. In the current manuscript, we aim to modify the surface of gold-nanoparticles (AuNPs) with PEG moiety and allow miRNA to attach to it. The fabricated nano-complex, not only delivered miR-206 but also caused cell death in MCF-7 by arresting cells in the G0-G1 phase and inducing apoptosis by downregulating NOTCH 3.

Role of microRNAs in the Pathophysiology of Ulcerative Colitis

Ulcerative colitis (UC) is an intractable disorder characterized by a chronic inflammation of the colon. Studies have identified UC as a multifactorial disorder affected by both genetic and environmental factors; however, the precise mechanism remains unclear. Recent advances in the field of microRNA (miRNA) research have identified an association between this small non-coding RNA in the pathophysiology of UC and altered miRNA expression profiles in patients with UC. Nevertheless, the roles of individual miRNAs are uncertain due to heterogeneity in both research samples and clinical backgrounds. In this review, we focus on miRNA expression in colonic mucosa where inflammation occurs in UC and discuss the potential roles of individual miRNAs in disease development, outlining the pathophysiology of UC.

Identification of colorectal cancer associated biomarkers: an integrated analysis of miRNA expression

Colorectal cancer is one of the leading causes of cancer-related deaths worldwide. This complex disease still holds severe problems concerning diagnosis due to the high invasiveness nature of colonoscopy and the low accuracy of the alternative diagnostic methods. Additionally, patient heterogeneity even within the same stage is not properly reflected in the current stratification system. This scenario highlights the need for new biomarkers to improve non-invasive screenings and clinical management of patients. MicroRNAs (miRNAs) have emerged as good candidate biomarkers in cancer as they are stable molecules, easily measurable and detected in body fluids thus allowing for non-invasive diagnosis and/or prognosis. In this study, we performed an integrated analysis first using 4 different datasets (discovery cohorts) to identify miRNAs associated with colorectal cancer development, unveil their role in this disease by identifying putative targets and regulatory networks and investigate their ability to serve as biomarkers. We have identified 26 differentially expressed miRNAs which interact with frequently deregulated genes known to participate in commonly altered pathways in colorectal cancer. Most of these miRNAs have high diagnostic power, and their prognostic potential is evidenced by panels of 5 miRNAs able to predict the outcome of stage II and III colorectal cancer patients. Notably, 8 miRNAs were validated in three additional independent cohorts (validation cohorts) including a plasma cohort thus reinforcing the value of miRNAs as non-invasive biomarkers.

Cervical cancer development, chemoresistance, and therapy: a snapshot of involvement of microRNA

Cervical cancer (CC) is one of the leading causes of death in women due to cancer and a major concern in the developing world. Persistent human papilloma virus (HPV) infection is the major causative agent for CC. Besides HPV infection, genetic and epigenetic factors including microRNA (miRNA) also contribute to the malignant transformation. Earlier studies have revealed that miRNAs participate in cell proliferation, invasion and metastasis, angiogenesis, and chemoresistance processes by binding and inversely regulating the target oncogenes or tumor suppressor genes. Based on functions and mechanistic insights, miRNAs have been identified as cellular modulators that have an enormous role in diagnosis, prognosis, and cancer therapy. Signatures of miRNA could be used as diagnostic markers which are necessary for early diagnosis and management of CC. The therapeutic potential of miRNAs has been shown in CC; however, more comprehensive clinical trials are required for the clinical translation of miRNA-based diagnostics and therapeutics. Understanding the molecular mechanism of miRNAs and their target genes has been useful to develop miRNA-based therapeutic strategies for CC and overcome chemoresistance. In this review, we summarize the role of miRNAs in the development, progression, and metastasis of CC as well as chemoresistance. Further, we discuss the diagnostic and therapeutic potential of miRNAs to overcome chemoresistance and treatment of CC.

miRNA-34a-5p regulates progression of neuroblastoma via modulating the Wnt/β-catenin signaling pathway by targeting SOX4

Neuroblastoma is an embryonal tumor of the autonomic nervous system with poor prognosis in children. In present study, we demonstrated the relationship of miRNA-34a-5p in the regulating of the Wnt/β-catenin signaling pathway by targeting SRY-related HMG-box (SOX4)Reverse transcription-quantitative PCR was used to detect the expression levels of miRNA-34a-5p and SoX4. Western blotting was performed to assess the protein expression levels of SoX4, Wnt, MMP9, Bax, and Bcl-2. The proliferation, apoptosis, migration and invasion of neuroblastoma cells were determined using MTT, flow cytometry and Transwell assays.In this study, we sought to investigate the role of miRNA-34a-5p on neuroblastoma and the possible molecular mechanism. We had performed in-vitro and in-vivo experiments to evaluate the effects of miRNA-34a-5p on neuroblastoma cell proliferation and invasion by altering its expression level via cell transfection. On the basis of our study, miRNA-34a-5p showed decreased expression levels in neuroblastoma. Subsequently, we manipulated miRNA-34a-5p expression through cell transfection and observed abnormal expression of β-catenin as well as the downstream targets of the Wnt/β-catenin pathway in neuroblastoma cells. With all these evidences, we determined that miRNA-34a-5p regulated Wnt/β-catenin pathway by targeting SOX4.In conclusion, our study demonstrates that miRNA-34a-5p can inhibit the over-activation of the Wnt/β-catenin signaling pathway via targeting SOX4 and further regulate proliferation, invasion of neuroblastoma cells.

MicroRNAs Regulating Hippo-YAP Signaling in Liver Cancer

Liver cancer is one of the most common cancers worldwide, and its prevalence and mortality rate are increasing due to the lack of biomarkers and effective treatments. The Hippo signaling pathway has long been known to control liver size, and genetic depletion of Hippo kinases leads to liver cancer in mice through activation of the downstream effectors yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ). Both YAP and TAZ not only reprogram tumor cells but also alter the tumor microenvironment to exert carcinogenic effects. Therefore, understanding the mechanisms of YAP/TAZ-mediated liver tumorigenesis will help overcome liver cancer. For decades, small noncoding RNAs, microRNAs (miRNAs), have been reported to play critical roles in the pathogenesis of many cancers, including liver cancer. However, the interactions between miRNAs and Hippo-YAP/TAZ signaling in the liver are still largely unknown. Here, we review miRNAs that influence the proliferation, migration and apoptosis of tumor cells by modulating Hippo-YAP/TAZ signaling during hepatic tumorigenesis. Previous findings suggest that these miRNAs are potential biomarkers and therapeutic targets for the diagnosis, prognosis, and treatment of liver cancer.

Updated review on green tea polyphenol epigallocatechin-3-gallate as a cancer epigenetic regulator

In-depth insights in cancer biology over the past decades have highlighted the important roles of epigenetic mechanisms in the initiation and progression of tumorigenesis. The cancer epigenome usually experiences multiple alternations, including genome-wide DNA hypomethylation and site-specific DNA hypermethylation, various histone posttranslational modifications, and dysregulation of non-coding RNAs (ncRNAs). These epigenetic changes are plastic and reversible, and could potentially occur in the early stage of carcinogenesis preceding genetic mutation, offering unique opportunities for intervention therapies. Therefore, targeting the cancer epigenome or cancer epigenetic dysregulation with some selected agents (called epi-drugs) represents an evolving and promising strategy for cancer chemoprevention and therapy. Phytochemicals, as a class of pleiotropic molecules, have manifested great potential in modulating different cancer processes through epigenetic machinery, of which green tea polyphenol epigallocatechin-3-gallate (EGCG) is one of the most extensively studied. In this review, we first summarize epigenetic events involved in the pathogenesis of cancer, including DNA/RNA methylations, histone modifications and ncRNAs' dysregulations. We then focus on the recently discovered roles of phytochemicals, with a special emphasis on EGCG, in modulating different cancer processes through regulating epigenetic machinery. We finally discuss limitations of EGCG as an epigenetic modulator for cancer chemoprevention and treatment and offer potential strategies to overcome the shortcomings.

Expression and Regulatory Network Analysis of MiR-139-3p, a New Potential Serum Biomarker for Esophageal Squamous Cell Carcinoma Based on Bioinformatics Analysis

Background:

In recent studies, microRNAs have been demonstrated as stable detectable biomarkers in blood for cancer. In addition, computer-aided biomarker discovery has now become an attractive paradigm for precision diagnosis.

Methods:

In this study, we identified and evaluated miR-139-3p as a biomarker for screening of esophageal squamous cell carcinoma using the Cancer Genome Atlas and Gene Expression Omnibus database analyses. We identified possible miR-139-3p target genes through the predicted database and esophageal squamous cell carcinoma upregulated genes from the Cancer Genome Atlas and Gene. Bioinformatics analysis was performed to determine key miR-139-3p targets and pathways associated with esophageal carcinoma. Finally, the expression and expected significance of hub genes were evaluated via the Genotype-Tissue Expression project.

Results:

MiR-139-3p was significantly downregulated in patients with esophageal squamous cell carcinoma/esophageal carcinoma. In GSE 122497, the area under the curve-receiver operating characteristic value, sensitivity, and specificity for serum miR-139-3p were 0.754, 67.49%, and 80.00%, respectively. The pattern specification process, skeletal system development, and regionalization process were the most enriched interactions in esophageal carcinoma. In addition, Epstein-Barr virus infection, human T-cell leukemia virus 1 infection, and human cytomegalovirus infection were identified as crucial pathways. Six hub genes (CD1A, FCGR2A, ANPEP, CD1B, membrane metalloendopeptidase, and TWIST1) were found, and FCGR2A and membrane metalloendopeptidase were further confirmed by genotype-tissue expression. High expression of membrane metalloendopeptidase correlated with a better overall survival but not with disease-free survival of patients with esophageal carcinoma.

Conclusions:

MiR-139-3p was identified as a candidate biomarker for predicting esophageal squamous cell carcinoma based on network analysis. MiR-139-3p acted as a tumor suppressor by targeting membrane metalloendopeptidase in esophageal carcinoma, and low expression of membrane metalloendopeptidase may indicate a better prognosis of patients with esophageal carcinoma.

MiR-130a-3p blocks Wnt signaling cascade in the triple-negative breast cancer by targeting the key players at multiple points

OBJECTIVES

Aberrant Wnt signaling cascade is a hallmark of the triple-negative breast cancer (TNBC) that is linked with the increased proliferation, invasion, and poor overall survival. many genes are post-transcriptionally regulated by microRNAs (miRNAs) therefore; it is indisputable that the dysregulation of the miRNAs is an explanation for the aberrant signaling cascades. Thus, the present study was conducted to find the putative miRNA targeting the key players of Wnt/β -catenin cascade in the TNBC.

METHODS

The miR-130a-3p was found as a potential regulator of the Wnt signaling cascade by applying several bioinformatic algorithms. Quantitative real-time PCR (qRT-PCR) was used to analyze the expression levels of miR-130a-3p and Wnt cascade genes in the TNBC cells. Afterward, TNBC cells were transiently transfected with the miR-130a-3p to investigate its effects on the expression of Wnt cascade genes. Subsequently, MTT, soft agar colony formation, scratch, transwell cell migration, and transwell cell invasion assays were used to determine the behavior of the TNBC cells in response to miR-130a-3p restoration.

RESULTS

Results of the qRT-PCR showed downregulation of miR-130a-3p and upregulation of the Wnt cascade genes in the TNBC cells compared to the normal cells. Transient overexpression of miR-130a-3p decreased the expression levels of Wnt cascade genes significantly in the TNBC cells. Moreover, following the miR-130a-3p overexpression, the proliferation, anchorage-independent growth, and migration of the TNBC cells were reduced.

CONCLUSION

Overall, our findings provided an evidence for the significant role of miR-130a-3p in the regulation of Wnt/β-catenin cascade, and also introduced the miR-130a-3p as a new therapeutic target for the patients with TNBC.

Lnc HAGLR Promotes Colon Cancer Progression Through Sponging miR-185-5p and Activating CDK4 and CDK6 in vitro and in vivo

BACKGROUND/AIM

LncRNA plays a key role in tumor progression. HAGLR functions as an oncogene in many cancers. However, the molecular mechanism of HAGLR in colon cancer is still unclear.

METHODS

qRT-PCR was used to measure the expression of HAGLR, miR-185-5p in colon cancer. The expression of CDK4 and CDK6 was detected by Western blot. CCK-8 assay, EdU staining, transwell and Annexin V-FITC/PI assay were used to analyze the effect of HAGLR and miR-185-5p on cell proliferation, invasion, migration and apoptosis. Bioinformatic analysis and luciferase were used to analyze the target genes of HAGLR and miR-185-5p. Nude mice were used to detect mouse tumor changes.

RESULTS

Compared with normal colon cancer tissues and cells, the expression of HAGLR was increased in colon cancer tissues and cells. In addition, the expression of HAGLR down-regulation inhibited the growth, migration, and invasion of colon cancer cells. MiR-185-5p was reduced in colon cancer, and CDK4 and CDK6 acted as target genes of miR-185-5p to regulate the progress of colon cancer. And CDK4 and CDK6 were predicted as downstream targets of miR-185-5p. Finally, it was demonstrated that HAGLR regulated tumor progression in vivo.

CONCLUSION

Lnc HAGLR promoted the development of colon cancer by miR-185-5p/CDK4/CDK6 axis, and lnc HAGLR might be potential target for colon cancer.

Exosomal MicroRNAs as Liquid Biopsy Biomarkers in Hepatocellular Carcinoma

Purpose

Hepatocellular carcinoma (HCC) has a high incidence in China and exploring effective ways for early diagnosis is an important method to improve the prognosis of patients with HCC. Additional studies reported that. Some kinds of microRNA (miRNA) in plasma will change accordingly during HCC progress, and this change can be used to diagnose HCC, especially with miRNA-122, miRNA-21 and miRNA-96. We were aiming at investigating the values of the exosomal miRNAs in diagnosis and prognosis for HCC patients.

Patients and Methods

Blood samples from 50 patients with HCC and 50 patients with hepatic cirrhosis and 50 healthy volunteers were obtained. The diagnostic accuracy of the plasma and exosomal miRNAs and the comparisons among different groups were measured by the area under the curve (AUC) on receiver operating characteristic (ROC) curve analysis.

Results

Expression levels of miRNA-21 and miRNA-96 were significantly higher in patients with HCC and of miRNA-122 were significantly lower in HCC compared with cirrhotic patients in both exosomes and plasma. Among different groups, exosomal miRNA-122, miRNA-21 and miRNA-96 were significantly more accurate in diagnosing HCC than those miRNAs in plasma and the alpha-fetoprotein (AFP) level. The miRNA panel had high accuracy in discriminating HCC from the cirrhosis group (AUC 0.924; 95% CI; sensitivity 82%, specificity 92%) and healthy volunteers’ group. Exosomal miRNA-21 and miRNA-96 with low expression and miRNA-122 with high expression could be associated with a patient’s survival time. However, the miRNA panel could better predict the HCC patient’s survival time compared with each miRNA individually.

Conclusion

This study showed that the expression levels of miRNA-122, miRNA-21 and miRNA-96 in exosomes were more significantly changed than those miRNAs in plasma in patients with HCC compared with cirrhotic patients, and the exosomal miRNA panel containing miRNA-122, miRNA-21 and miRNA-96 could be defined as a diagnostic biomarker for patients with HCC. We also conclude that different expression of exosomal miRNAs, especially the miRNA panel, could predict the HCC patient’s prognosis.

The mir-767-105 cluster: a crucial factor related to the poor prognosis of hepatocellular carcinoma

MiRNAs have been widely reported as the therapeutic target for hepatocellular carcinoma (HCC). However, mirna clusters, as the more impressive tumor regulatory factors, have received little attention. By deeply digging the Cancer Genome Atlas (TCGA) database, we aimed to explore the vital mirna cluster that regulated the poor prognosis of HCC. The results showed that the upregulation of mirna cluster-767-105 in HCC was the most significant, compared with the non-tumor tissues. Besides, high expression of all three members of the cluster was positively correlated with poor prognosis of HCC and the resistance of sorafenib. Cox analysis proved that all the three mirnas were independent prognostic factors, while the mir-767 was the most compelling (HR value 8.388, 95%CI 2.524–27.897). The higher expression of the three-mirna signature also significantly indicated the worse prognosis. Through bioinformatics analysis, we screened their common potential target genes, which were highly correlated with tumor regulation. These results supported that the mirna cluster-767-105 promoted the poor outcome of HCC and could be a robust target for the therapy of HCC patients.

MicroRNA regulation of natural killer cell development and function in leukemia

MicroRNAs (miRNAs) are now recognized as important regulators of all cellular processes, including immune function and cancer survival. These evolutionary preserved, single-stranded, non-coding RNA molecules mediate important functional effects primarily through post-transcriptional regulation of protein expression. MiRNAs are known to mediate multiple oncogenic pathways in tumor cells, both tumor promoting and tumor suppressing. In addition to a direct tumor cell effect, miRNAs have also been shown to play a critical role in immune cell development, function and survival. Here we expand on previous reports to evaluate miRNA regulation in natural killer (NK) cells primarily in humans and focus on their influence on NK cell development and function in the setting of hematologic malignancies. In addition, we highlight the most recent miRNA discoveries in hematologic malignancies and discuss areas of future exploration relevant to the translational field of innate immunology and miRNA-based therapeutic intervention.

The Regulatory Role of MicroRNAs in Breast Cancer

MicroRNAs (miRNAs) are small non-coding RNA molecules which function as critical post-transcriptional gene regulators of various biological functions. Generally, miRNAs negatively regulate gene expression by binding to their selective messenger RNAs (mRNAs), thereby leading to either mRNA degradation or translational repression, depending on the degree of complementarity with target mRNA sequences. Aberrant expression of these miRNAs has been linked etiologically with various human diseases including breast cancer. Different cellular pathways of breast cancer development such as cell proliferation, apoptotic response, metastasis, cancer recurrence and chemoresistance are regulated by either the oncogenic miRNA (oncomiR) or tumor suppressor miRNA (tsmiR). In this review, we highlight the current state of research into miRNA involved in breast cancer, with particular attention to articles published between the years 2000 to 2019, using detailed searches of the databases PubMed, Google Scholar, and Scopus. The post-transcriptional gene regulatory roles of various dysregulated miRNAs in breast cancer and their potential as therapeutic targets are also discussed.

Nanotechnological based miRNA intervention in the therapeutic management of neuroblastoma

Neuroblastoma (NB) is a widely diagnosed cancer in children, characterized by amplification of the gene encoding the MYCN transcription factor, which is highly predictive of poor clinical outcome and metastatic disease. microRNAs (a class of small non-coding RNAs) are regulated by MYCN transcription factor in neuroblastoma cells. The current research is focussed on identifying differential role of miRNAs and their interactions with signalling proteins, which are intricately linked with cellular processes like apoptosis, proliferation or metastasis. However, the therapeutic success of miRNAs is limited by pharmaco-technical issues which are well counteracted by nanotechnological advancements. The nanoformulated miRNAs unload anti-cancer drugs in a controlled and prespecified manner at target sites, to influence the activity of target protein in amelioration of NB. Recent advances and developments in the field of miRNAs-based systems for clinical management of NBs and the role of nanotechnology to overcome challenges with drug delivery of miRNAs have been reviewed in this paper.

S100A6/miR193a regulates the proliferation, invasion, migration and angiogenesis of lung cancer cells through the P53 acetylation

Non-small cell lung cancer (NSCLC) is accounted for 80% to 85% of the total lung cancer cases and still a difficult problem to solve at present. The present study was aimed to explore the effect of S100A6 on the proliferation, invasion, migration and angiogenesis in lung cancer cell lines with the change of miR-193a expression and P53 acetylation. The expression of S100A6, CDK2, cyclinD1, VEGF, ANGII, anti-acetylp53 (K373), K-AC, P21 and Noxa were analyzed by western blot analysis. RT-qPCR analysis was used to confirm the transfection effects. CCK-8 assay and flow cytometry were reflecting the cell proliferation. Wound healing assay and transwell assay were evaluating the cell invasion and migration. The dual-luciferase reporter assay was to confirm the S100A6 as a target of miR-193a. Immunofluorescence and immunohistochemical analysis were analyzing the S100A6 expression in cells and tumor tissues, respectively. As a result, S100A6 expression was increased in lung cancer cell lines and S100A6 expressed the highest in A549 cells which was chosen for the subsequent experiment. S100A6 overexpression promoted the proliferation, invasion, migration and angiogenesis of lung cancer cells with the promotion of degradation of P53 acetylation. In addition, S100A6 was demonstrated to be a target of miR193a. Moreover, miR193a expression was decreased in lung cancer cell lines and miR193a expressed the lowest in A549 cells which was chosen for the subsequent experiment. And, miR193a overexpression inhibited the proliferation, invasion, migration and angiogenesis of lung cancer cells with the enhancement of P53 acetylation. The effects of S100A6 overexpression and miR193a overexpression on tumor growth in vivo experiments were the same with that in the cell experiments. In conclusion, this study indicated that S100A6 overexpression could promote the proliferation, invasion, migration and angiogenesis of lung cancer cells by inhibiting the P53 acetylation and miR193a overexpression could reversed the above effects by decreasing the S100A6 expression in both vitro and vivo experiments.

MiR-137 inhibits cell proliferation in acute lymphoblastic leukemia by targeting JARID1B

AIM

This study aimed to investigate the possible functions of interaction between JARID1B and miR-137 in ALL.

METHODS

The levels of H3K4me3 and H3K4me2 and the expression of JARID1B and miR-137 were analyzed in six ALL cell lines and 30 ALL patients. The effects of miR-137 and JARID1B on cell proliferation and apoptosis were investigated by silencing or promoting the respective genes. The interaction between miR-137 and JARID1B was confirmed by double-luciferase report assay.

RESULTS

The histone H3K4 expressions and miR-137 expression were lower in 30 ALL patients and in six ALL cell lines, while the expression of JARID1B was elevated. A negative correlation was observed between JARID1B and miR-137. Over-expression of miR-137 led to decreasing cell proliferation and increasing apoptosis in MOLT-4 and BALL-1 cells. MiR-137 inhibitor up-regulated JARID1B in these two cell lines, while promoted proliferation in BALL-1 cells only. Dual-luciferase report assay suggested that JARID1B was a direct target of miR-137 in ALL cell lines.

CONCLUSIONS

The expression of miR-137 was declined in ALL, and JARID1B was directly repressed by miR-137. Aberrant JARID1B expression could result in abnormal histone methylation, which might be one cause of ALL.

Roles of E-cadherin and Noncoding RNAs in the Epithelial-mesenchymal Transition and Progression in Gastric Cancer

The epithelial–mesenchymal transition (EMT) is thought to be at the root of invasive and metastatic cancer cell spreading. E-cadherin is an important player in this process, which forms the structures that establish and maintain cell–cell interactions. A partial or complete loss of E-cadherin expression in the EMT is presumably mediated by mechanisms that block the expression of E-cadherin regulators and involve the E-cadherin-associated transcription factors. The protein is involved in several oncogenic signaling pathways, such as the Wnt/β-catenin, Rho GTPase, and EGF/EGFR, whereby it plays a role in many tumors, including gastric cancer. Such noncoding transcripts as microRNAs and long noncoding RNAs—critical components of epigenetic control of gene expression in carcinogenesis—contribute to regulation of the E-cadherin function by acting directly or through numerous factors controlling transcription of its gene, and thus affecting not only cancer cell proliferation and metastasis, but also the EMT. This review focuses on the role of E-cadherin and the non-coding RNAs-mediated mechanisms of its expressional control in the EMT during stomach carcinogenesis.

MicroRNA-124 Dysregulation is Associated With Retinal Inflammation and Photoreceptor Death in the Degenerating Retina

Purpose

We sought to determine the role and retinal cellular location of microRNA-124 (miR-124) in a neuroinflammatory model of retinal degeneration. Further, we explored the anti-inflammatory relationship of miR-124 with a predicted messenger RNA (mRNA) binding partner, chemokine (C-C motif) ligand 2 (Ccl2), which is crucially involved in inflammatory cell recruitment in the damaged retina.

Methods

Human AMD donor eyes and photo-oxidative damaged (PD) mice were labeled for miR-124 expression using in situ hybridization. PDGFRa-cre RFP mice were used for Müller cell isolation from whole retinas. MIO-M1 immortalized cells and rat primary Müller cells were used for in vitro analysis of miR-124 expression and its relationship with Ccl2. Therapeutic efficacy was tested with intravitreal administration of miR-124 mimic in mice, with electroretinography used to determine retinal function. IBA1 immunohistochemistry and photoreceptor row counts were used for assessment of inflammation and cell death.

Results

MiR-124 expression was correlated with progressive retinal damage, inflammation, and cell death in human AMD and PD mice. In addition, miR-124 expression was inversely correlated to Ccl2 expression in mice following PD. MiR-124 was localized to both neuronal-like photoreceptors and glial (Müller) cells in the retina, with a redistribution from neurons to glia occurring as a consequence of PD. Finally, intravitreal administration of miR-124 mimics decreased retinal inflammation and photoreceptor cell death, and improved retinal function.

Conclusions

This study has provided an understanding of the mechanism behind miR-124 in the degenerating retina and demonstrates the usefulness of miR-124 mimics for the modulation of retinal degenerations.

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.

Diagnostic value of a microRNA signature panel in exosomes for patients with hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the fifth most frequently diagnosed cancer worldwide and the second most frequent cause of cancer death. The aim of this study is to investigate the early diagnostic value of a panel of peripheral blood exosomal micro-RNAs (miRNAs) in patients with HCC compared with patients with Hepatitis B virus (HBV) and hepatocirrhosis.

PATIENTS AND METHODS

Blood samples from 72 patients with HCC, 72 patients with hepatocirrhosis and 72 patients with HBV were obtained at Beijing Friendship Hospital, Capital Medical University. The miRNA expression levels were detected by real-time polymerase chain reaction (RT-PCR). Areas under curve (AUCs) were used to compare diagnostic values of plasmic and exosomal miRNAs.

RESULTS

We screened plasmic and exosomal solutions of 3 HCC, 3 cirrhosis and 3 HBV patients to perform miRNA microarray analysis. Three distinctly differential microRNAs including miRNA-26a, miRNA-29c, and miRNA-21 were selected to perform further evaluation. First, we found that the expressions of miRNA-26a, miRNA-29c, and miRNA-21 were significantly lower in patients with HCC compared with cirrhotic and HBV group in both exosomes and plasma. Second, we found miRNA-26a, miRNA-29c, and miRNA-21 were significantly down-regulated in HCC tumor tissues compared with normal tissues. Thirdly, we found miRNAs in exosomes had better diagnostic value for patients with HCC compared with plasmic miRNAs among different groups.

CONCLUSIONS

In conclusion, we found that the expression of miRNA-26a, miRNA-29c, and miRNA-21 were significantly lower in patients with HCC, and we confirmed miRNA-26a, miRNA-29c, and miRNA-21 could be identified as independent diagnostic biomarkers for patients with HCC.

Increased Expression of MicroRNA 551a by c-Fos Reduces Focal Adhesion Kinase Levels and Blocks Tumorigenesis

Breast cancer is a recurrent type of cancer among women worldwide. Despite remarkable progress in the prevention, detection, and treatment of breast cancer, it still remains a major chronic problem worldwide and poses significant challenges, like metastasis to distant organs, demanding the need for novel biomarkers and therapeutic targets. Focal adhesion kinase (FAK), a member of the protein tyrosine kinases, has been shown to be expressed in high levels in breast tumors. Of late, FAK has emerged as an impending curative target in breast carcinoma, with few of the small molecular inhibitors reaching the clinical trial stage. In the current study, we established that microRNA 551a (miR-551a) precisely regulates FAK by binding to the complementary sequences in the 3' untranslated region (UTR) of mRNAs of FAK and inhibits its expression in breast carcinoma cell lines. Further, results from human breast carcinoma samples illustrated that miR-551a levels were substantially downregulated in tumor samples, with a concurrent rise in the expression of FAK. Functional experimental studies using miR-551a-overexpressing breast cancer cells and nude mouse xenograft models revealed the tumor suppressor role of miR-551a. We also found that miR-551a expression decreased the invasion and migratory ability of breast carcinoma cells by inhibiting MMP-9 activity. Regulation studies performed utilizing promoter luciferase assays, chromatin immunoprecipitation (ChIP), and electrophoretic mobility shift assay (EMSA) revealed that c-Fos binds to the miR-551a promoter and activates it. Further, we observed a considerable increase in the amount of miR-551a levels upon c-Fos overexpression. All of these results showed that miR-551a can be of clinical relevance in understanding the regulation of FAK in breast tumorigenesis.

miR-30a inhibits breast cancer progression through the Wnt/β-catenin pathway

BACKGROUND

miR-30a is a microRNA associated with the progression of malignant tumors such as gastric cancer, colon cancer, prostate cancer, and lung cancer, and can regulate the proliferation and migration of breast cancer (BC) cells in vitro. However, its expression, function, clinical significance and relationship with the Wnt/β-catenin pathway in human BC were still unclear.

METHODS

Immunohistochemistry, Western blotting and real-time quantitative PCR (RT-qPCR) were used to measure the expressions of miR-30a and β-catenin in 114 pairs of human BC tumor tissues and adjacent normal tissues which were collected from March 2014 to October 2015. The effect of miR-30a on the expression of β-catenin was studied in the MCF-7 cells in vitro.

RESULTS

The expression levels of miR-30a in human BC tumor tissues were significantly lower than they were in the adjacent normal tissues (P < 0.001), and significantly higher in β-catenin protein (P < 0.001), but there was no significant different in β-catenin mRNA (P = 0.3816). The immunohistochemistry results showed that β-catenin protein was only expressed on the cell membrane in paracancerous normal tissues, but β-catenin protein was expressed on the cell membrane and cytoplasm in BC tumor cells. In addition, there was a significantly negative correlation (r = -0.816, P < 0.001) between the expression miR-30a and β-catenin protein in BC tissues. The age of onset, PR expression, ER expression, and HER-2 expression of the BC patients were not related to miR-30a or β-catenin protein expression (P > 0.05). Tumor diameter, histological grade, lymph node metastasis, TNM stage, and the prognosis of BC patients (P < 0.05) were significantly related to miR-30a or β-catenin protein expression. In MCF-7 cells, miR-30a regulated the accumulation of β-catenin protein by inhibiting the expression of BCL9 in BC cells.

CONCLUSION

miR-30a was lowly expressed in breast cancer tissues and highly in β-catenin protein, and miR-30a might block the Wnt/β-catenin pathway by inhibiting the accumulation of β-catenin, and then inhibiting breast cancer progression.

MicroRNA-17, MicroRNA-19b, MicroRNA-146a, MicroRNA-302d Expressions in Hepatoblastoma and Clinical Importance

Hepatoblastoma (HB) is the most common liver malignancy in children. The prognosis changes according to the histologic subtypes of HB. In the present study, we aimed to characterize the expression level of selected microRNAs (miRNAs) in HB as well as in histologic subtypes, and to consider the association with the prognosis. A total of 22 HB tumor samples, subtyped as fetal (n=16) and embryonal (n=6), and 10 nontumorous surrounding liver samples were evaluated in this study. Expressions of miR-17, miR-146a, miR-302d, and miR-19b were analyzed in 22 HB tumor samples and 10 nontumorous surrounding liver samples by quantitative real-time polymerase chain reaction. Lower miRNA-17 expression levels were obtained in tumor samples in comparison with nontumorous surrounding liver samples (P=0.028). Lower miRNA-17 expression was significant for predicting prognosis in HB patients (area under receiver-operator characteristic curve=0.875, P=0.044). A higher-level of miR-19b was found in embryonal samples (P=0.008). Overall and event-free survival was not found to correlate with miRNA expression levels (P>0.05). This research finds miRNA-17 and miRNA-19b expression levels can provide important data on diagnosis and prognosis in HB showing different clinical behaviors.

Therapeutic microRNAs in human cancer

MicroRNAs (miRNAs) are RNA molecules at about 22 nucleotide in length that are non-coding, which regulate gene expression in the post-transcriptional level by performing degradation or blocks translation of the target mRNA. It is known that they play roles in mechanisms such as metabolic regulation, embryogenesis, organogenesis, differentiation and growth control by providing post-transcriptional regulation of gene expression. With these properties, miRNAs play important roles in the regulation of biological processes such as proliferation, differentiation, apoptosis, drug resistance mechanisms in eukaryotic cells. In addition, there are miRNAs that can be used for cancer therapy. Tumor cells and tumor microenvironment have different miRNA expression profiles. Some miRNAs are known to play a role in the onset and progression of the tumor. miRNAs with oncogenic or tumor suppressive activity specific to different cancer types are still being investigated. This review summarizes the role of miRNAs in tumorigenesis, therapeutic strategies in human cancer and current studies.

Sevoflurane anesthesia represses neurogenesis of hippocampus neural stem cells via regulating microRNA-183-mediated NR4A2 in newborn rats

Sevoflurane has been commonly utilized in nonobstetric surgeries in pregnant women, and its impacts on fetal brain are still not completely known. Ectopic NR4A2 expression has been reported to be related with familial Parkinson disease, and through dual luciferase we found that NR4A2 is a target gene of microRNA-183 (miR-183). We proposed a hypothesis that miR-183 may participate in the process by targeting NR4A2 in neurons after sevoflurane anesthesia. To verify the effect of sevoflurane on hippocampal neural stem cells (NSCs) proliferation and differentiation, we conducted EdU assay and immunofluorescence staining. Next, for better understanding of the impact of miR-183, we altered the miR-183 expression using mimic and inhibitor. Meanwhile, the targeting relationship between miR-183 and NR4A2 was validated by a bioinformatics website and dual-luciferase reporter gene assay. Finally, expressions of miR-184, NR4A2, SRY (sex-determining region Y)-box 2 (Sox2), and brain-derived neurotrophic factor (BDNF) were determined and evaluated by reverse transcription quantitative polymerase chain reaction and western blot analysis. First, sevoflurane was determined a crucial factor in biological behaviors of hippocampal NSCs. Moreover, upregulated miR-183 expression by mimic inhibited the proliferation and differentiation of NSCs. Sevoflurane negatively regulated NR4A2 and Sox2 expressions but positively regulated miR-183 and BDNF expressions. Our findings revealed the underlying novel mechanism by which sevoflurane inhibits hippocampal NSC proliferation and differentiation through interaction with miR-183 and NR4A2. The study provides reliable reference for safe application of sevoflurane anesthesia in neonates.

RNA-binding protein PUM2 suppresses osteosarcoma progression via partly and competitively binding to STARD13 3'UTR with miRNAs

OBJECTIVES

This work aims to reveal the roles and related mechanisms of RNA binding protein PUM2 in osteosarcoma progression.

MATERIALS AND METHODS

Transcriptome analysis based on RNA sequencing data, real-time quantitative PCR (RT-qPCR), and western blot analysis were used to detect the expression of RBPs and miRNAs in OS and normal adjacent tissues, and the correlation between them in OS tissues. RT-qPCR, western blot, cell viability, transwell migration, tumour spheres formation and in vivo tumour formation assays were used to examine the effects of RBP PUM2 on OS progression. Additionally, RNA immunoprecipitation (RIP) assay combined with RNA sequencing was performed to determine the binding site of RBP PUM2 on STARD13 3'UTR. Luciferase reporter and RIP assays were used to confirm the binding of miRNAs or PUM2 on STARD13 3'UTR.

RESULTS

PUM2 and STARD13 expression was significantly decreased in OS tissues, and positively correlated. Overexpression of PUM2 or STARD13 3'UTR inhibited OS cells proliferation, migration, and stemness. Mechanistically, PUM2 competitively bound to STARD13 3'UTR with miR-590-3p and miR-9. The inhibition of PUM2 on OS cells progression was attenuated by STARD13 knockdown or related miRNAs overexpression.

CONCLUSION

PUM2 suppresses OS progression via partly and competitively binding to STARD13 3'UTR with miRNAs.