MicroRNA miR-125b causes leukemia. Proc Natl Acad Sci U S A. 2010;107:21558-21563. [PMID: 21118985 DOI: 10.1073/pnas.1016611107]

MicroRΝΑ analysis in patients with myelodysplastic neoplasms. Possible implications in risk stratification

MiRNAs have been identified as participants in leukemogenesis by controlling several cellular functions, such as differentiation, proliferation, and apoptosis. Their role in myelodysplastic neoplasms (MDS) pathogenesis is researched due to implementations in early identification, classification, and therapeutical options. IPSS-R, being the most widely used MDS classification, underestimates early biological events that can alter the disease's prognosis. The purpose of this study is to determine whether miRNA levels are aligned to MDS risk stratification groups and can therefore be used as diagnostic biomarkers. To evaluate miRNAs as possible biomarkers, we measured the levels of miR-181a-2-3p, miR-124-3p, miR-550a-3p, miR-155-5p, miR-151a-3p, and miR-125b-5p by a quantitative real-time PCR in bone marrow samples of 41 MDS patients. In conclusion, in myeloid malignancies, genomic characteristics may provide a wider apprehension of its clinical course and prognosis. MiRNAs constitute a possible diagnostic biomarker and therapeutic target, allowing intermediate-risk patients that express high levels of specific miRNAs to be re-classified and receive more advanced therapeutic agents. In our study, an association between high levels of miRNAs and worsening outcomes is established, supporting the need for further incorporation of molecular data into currently used classification systems.

The AC010247.2/miR-125b-5p axis triggers the malignant progression of acute myelocytic leukemia by IL-6R

AML is a malignant tumor derived from the hematopoietic system, which has a poor prognosis and its incidence is increasing recent years. LncRNAs bind to miRNAs as competitive endogenous RNAs to regulate the occurrence and progression of AML， with IL-6R playing a crucial role in hematological malignancies. However, the mechanism by which noncoding RNAs regulate IL6R expression in AML remains unclear. This study found that the AC010247.2/miR-125b-5p axis promotes AML progression by regulating IL-6R expression. Specifically, knocking down or inhibiting AC010247.2 and miR-125b-5p affected IL6R and its downstream genes. Mechanistically, AC010247.2 acts as a ceRNA for miR-125b-5p, influencing IL-6R expression. Additionally, AC010247.2's regulation of AML progression partially depends on miR-125b-5p. Notably, the AC010247.2/miR-125b-5p/IL6R axis serves as a better polygenic diagnostic marker for AML. Our study identifies a key ceRNA regulatory axis that modulates IL6R expression in AML, providing a reliable multigene diagnostic method and potential therapeutic target.

Advances in delivery systems for CRISPR/Cas-mediated cancer treatment: a focus on viral vectors and extracellular vesicles

The delivery of CRISPR/Cas systems holds immense potential for revolutionizing cancer treatment, with recent advancements focusing on extracellular vesicles (EVs) and viral vectors. EVs, particularly exosomes, offer promising opportunities for targeted therapy due to their natural cargo transport capabilities. Engineered EVs have shown efficacy in delivering CRISPR/Cas components to tumor cells, resulting in inhibited cancer cell proliferation and enhanced chemotherapy sensitivity. However, challenges such as off-target effects and immune responses remain significant hurdles. Viral vectors, including adeno-associated viruses (AAVs) and adenoviral vectors (AdVs), represent robust delivery platforms for CRISPR/Cas systems. AAVs, known for their safety profile, have already been employed in clinical trials for gene therapy, demonstrating their potential in cancer treatment. AdVs, capable of infecting both dividing and non-dividing cells, offer versatility in CRISPR/Cas delivery for disease modeling and drug discovery. Despite their efficacy, viral vectors present several challenges, including immune responses and off-target effects. Future directions entail refining delivery systems to enhance specificity and minimize adverse effects, heralding personalized and effective CRISPR/Cas-mediated cancer therapies. This article underscores the importance of optimized delivery mechanisms in realizing the full therapeutic potential of CRISPR/Cas technology in oncology. As the field progresses, addressing these challenges will be pivotal for translating CRISPR/Cas-mediated cancer treatments from bench to bedside.

The interplay between microRNAs and Nrf2 signaling in human cancers

MicroRNAs (miRNAs), as a class of nonprotein-coding RNAs, post-transcriptionally regulate the expression of target genes by base pairing to 3'-untranslated regions (3'-UTRs). Nuclear factor E2-related factor 2 (Nrf2) has been identified as a critical component of the antioxidant defense mechanism. Dysregulation is associated with chemoresistance and radioresistance in cancerous cells. MiRNA-mediated regulation of the Nrf2 signaling pathway has been shown to have important implications for the development of various cancers. In this article, we review the roles of miRNAs as regulators of the Nrf2 pathway in different human cancers. Ras-associated binding (Rab) proteins have an essential role regulation of vesicle transport, as well as oncogenic functions in preventing chemotherapy efficacy and cancer development. More importantly, increased evidence indicated that the interaction between miRNAs and Rabs has been determined to play critical roles in cancer therapy. However, the significant limitations in using miRNAs for therapeutic applications include cross-targeting and instability of miRNAs. The detailed aspect of the interaction of miRNAs and Rabs is not clearly understood. In the current review, we highlighted the involvement of these molecules as regulators of the Nrf2 pathway in cancer pathogenesis. Potential methods and several obstacles in developing miRNAs as an anticancer therapy are also mentioned.

Identification of exosomal microRNAs and related hub genes associated with imatinib resistance in chronic myeloid leukemia

Chemotherapy resistance is a major obstacle in cancer therapy, and identifying novel druggable targets to reverse this phenomenon is essential. The exosome-mediated transmittance of drug resistance has been shown in various cancer models including ovarian and prostate cancer models. In this study, we aimed to investigate the role of exosomal miRNA transfer in chronic myeloid leukemia drug resistance. For this purpose, firstly exosomes were isolated from imatinib sensitive (K562S) and resistant (K562R) chronic myeloid leukemia (CML) cells and named as Sexo and Rexo, respectively. Then, miRNA microarray was used to compare miRNA profiles of K562S, K562R, Sexo, Rexo, and Rexo-treated K562S cells. According to our results, miR-125b-5p and miR-99a-5p exhibited increased expression in resistant cells, their exosomes, and Rexo-treated sensitive cells compared to their sensitive counterparts. On the other hand, miR-210-3p and miR-193b-3p were determined to be the two miRNAs which exhibited decreased expression profile in resistant cells and their exosomes compared to their sensitive counterparts. Gene targets, signaling pathways, and enrichment analysis were performed for these miRNAs by TargetScan, KEGG, and DAVID. Potential interactions between gene candidates at the protein level were analyzed via STRING and Cytoscape software. Our findings revealed CCR5, GRK2, EDN1, ARRB1, P2RY2, LAMC2, PAK3, PAK4, and GIT2 as novel gene targets that may play roles in exosomal imatinib resistance transfer as well as mTOR, STAT3, MCL1, LAMC1, and KRAS which are already linked to imatinib resistance. MDR1 mRNA exhibited higher expression in Rexo compared to Sexo as well as in K562S cells treated with Rexo compared to K562S cells which may suggest exosomal transfer of MDR1 mRNA.

Biomarker potential of competing endogenous RNA networks in Polycystic Ovary Syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is the most common condition affecting women of reproductive age globally. PCOS continues to be the largest contributing factor to female infertility despite significant progress in our knowledge of the molecular underpinnings and treatment of the condition. The fact that PCOS is a very diverse condition makes it one of the key reasons why we haven't been able to overcome it. Non-coding RNAs (ncRNAs) are implicated in the development of PCOS, according to growing evidence. However, it is unclear how the complex regulatory relationships between the many ncRNA types contribute to the growth of this malignancy. Competing endogenous RNA (ceRNA), a recently identified mechanism in the RNA world, suggests regulatory interactions between various RNAs, including long non-coding RNAs (lncRNAs), microRNAs (miRNAs), transcribed pseudogenes, and circular RNAs (circRNAs). Recent studies on PCOS have shown that dysregulation of multiple ceRNA networks (ceRNETs) between these ncRNAs plays crucial roles in developing the defining characteristics of PCOS development. And it is believed that such a finding may open a new door for a deeper comprehension of PCOS's unexplored facets. In addition, it may be able to provide fresh biomarkers and effective therapy targets for PCOS. This review will go over the body of information that exists about the primary roles of ceRNETs before highlighting the developing involvement of several newly found ceRNETs in a number of PCOS characteristics.

Advantages of nanomedicine over the conventional treatment in Acute myeloid leukemia

Leukemia is a cancer of blood cells that mainly affects the white blood cells. In acute myeloid leukemia (AML) sudden growth of cancerous cells occurs in blood and bone marrow, and it disrupts normal blood cell production. Most patients are asymptomatic, but it spreads rapidly and can become fatal if left untreated. AML is the prevalent form of leukemia in children. Risk factors of AML include chemical exposure, radiation, genetics, etc. Conventional diagnostic methods of AML are complete blood count tests and bone marrow aspiration, while conventional treatment methods involve chemotherapy, radiation therapy, and bone marrow transplant. There is a risk of cancer cells spreading progressively to the other organs if left untreated, and hence, early diagnosis is required. The conventional diagnostic methods are time- consuming and have drawbacks like harmful side effects and recurrence of the disease. To overcome these difficulties, nanoparticles are employed in treating and diagnosing AML. These nanoparticles can be surface- modified and can be used against cancer cells. Due to their enhanced permeability effect and high surface-to-volume ratio they will be able to reach the tumour site which cannot be reached by traditional drugs. This review article talks about how nanotechnology is more advantageous over the traditional methods in the treatment and diagnosis of AML.

Bioinformatics-Guided Discovery of miRNAs Involved in Apoptosis Modulated by Parthenolide Combined with Vincristine in The NALM6 Cell Line

OBJECTIVE

Acute lymphoblastic leukemia (ALL) is a highly heterogeneous leukemia. Despite the current improvement in conventional chemotherapy and high survival rates, the outcomes remain challenging. Sesquiterpen extracted from the Tanacetum parthenium, parthenolide, is a potential anticancer agent that can modulate the expression of miRNAs and induce apoptosis. The objective of this study was to investigate the effect of parthenolide in combination with vincristine and alone on the apoptosis rate and expression of miR-125b-5p, miR-181b-5p, and miR-17-5p in the NALM6 cell line.

MATERIALS AND METHODS

In this experimental study, cell viability and metabolic activity were determined through MTT assay and PI staining. Flow cytometry was applied to evaluate the rate of apoptosis. The expression of miRNAs was assessed using real-time polymerase chain reaction. Bioinformatic analyses, including Cytoscape, RNAhybrid, and signaling pathway analysis were employed to investigate the association of miR-17-5p, miR-181b-5p and miR-125b- 5p with apoptosis. Further, molecular docking served to validate the modulation of these miRNAs by parthenolide and vincristine treatment.

RESULTS

The MTT assay indicated that 7.7 μM of parthenolide decreased the metabolic activity to 50% after 48 hours. PI staining analysis indicated that at concentrations below the half maximal inhibitory concentration, parthenolide caused 50% cell death. Flow cytometric analysis indicated that parthenolide (1.925 μM) in combination with vincristine (1.2 nM) induced apoptosis in 83.2% of the cells. Real-time quantitative reverse transcription polymerase chain reaction (qRTPCR) analysis showed significant changes in the expression levels of miR-17-5p, miR-125b-5p, and miR-181b-5p. Moreover, the combination therapy downregulated the expression of miRNAs significantly. This was consistent with our bioinformatic analysis demonstrating that the studied miRNAs are regulators of apoptosis. Finally, molecular docking validated the modulation of the miRNAs by parthenolide and vincristine.

CONCLUSION

Parthenolide in combination with vincristine triggers apoptosis at a high rate in the NALM6 cell line. Moreover, this combination therapy can decrease the expression of miR-17-5p, miR-181b-5p, and miR-125b-5p.

A novel therapeutic strategy: the significance of exosomal miRNAs in acute myeloid leukemia

Acute myeloid leukemia (AML) is a fast-growing blood cancer that interferes with the normal growth of blood cells in the bone marrow and blood. It is characterized by its unpredictable outlook and high death rate. The main treatment for AML is chemotherapy, but this often results in drug resistance and the possibility of the disease returning. For this reason, new biomarkers are necessary to diagnose, predict, and treat this disease. Research has demonstrated that cells responsible for AML release exosomes that interact with the disease's microenvironment. These exosomes have significant roles in promoting leukemia growth, suppressing normal hematopoiesis, facilitating angiogenesis, and contributing to drug resistance in AML. Further investigations have shown that these exosomes contain miRNAs, which are transferred to target cells and have functional roles. Biomarkers are utilized to assess various aspects of tumor cell behavior, including proliferation, apoptosis, angiogenesis, changes in the microenvironment, transfer of drug resistance, and stability in serum and blood plasma. In this research, we showed that exosomal miRNAs and exosomes have the potential to be used as indicators for detecting various phases of AML and can aid in its medical treatment. Furthermore, they can be specifically targeted for therapeutic purposes in addressing this condition.

Pancreatic Neuroendocrine Tumors: Signaling Pathways and Epigenetic Regulation

Pancreatic neuroendocrine tumors (PNETs) are characterized by dysregulated signaling pathways that are crucial for tumor formation and progression. The efficacy of traditional therapies is limited, particularly in the treatment of PNETs at an advanced stage. Epigenetic alterations profoundly impact the activity of signaling pathways in cancer development, offering potential opportunities for drug development. There is currently a lack of extensive research on epigenetic regulation in PNETs. To fill this gap, we first summarize major signaling events that are involved in PNET development. Then, we discuss the epigenetic regulation of these signaling pathways in the context of both PNETs and commonly occurring-and therefore more extensively studied-malignancies. Finally, we will offer a perspective on the future research direction of the PNET epigenome and its potential applications in patient care.

MicroRNAs Associated with a Bad Prognosis in Acute Myeloid Leukemia and Their Impact on Macrophage Polarization

MicroRNAs (miRNAs) are short, non-coding ribonucleic acids (RNAs) associated with gene expression regulation. Since the discovery of the first miRNA in 1993, thousands of miRNAs have been studied and they have been associated not only with physiological processes, but also with various diseases such as cancer and inflammatory conditions. MiRNAs have proven to be not only significant biomarkers but also an interesting therapeutic target in various diseases, including cancer. In acute myeloid leukemia (AML), miRNAs have been regarded as a welcome addition to the limited therapeutic armamentarium, and there is a vast amount of data on miRNAs and their dysregulation. Macrophages are innate immune cells, present in various tissues involved in both tissue repair and phagocytosis. Based on their polarization, macrophages can be classified into two groups: M1 macrophages with pro-inflammatory functions and M2 macrophages with an anti-inflammatory action. In cancer, M2 macrophages are associated with tumor evasion, metastasis, and a poor outcome. Several miRNAs have been associated with a poor prognosis in AML and with either the M1 or M2 macrophage phenotype. In the present paper, we review miRNAs with a reported negative prognostic significance in cancer with a focus on AML and analyze their potential impact on macrophage polarization.

The Importance of Selected Dysregulated microRNAs in Diagnosis and Prognosis of Childhood B-Cell Precursor Acute Lymphoblastic Leukemia

B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is a frequent type of childhood hematological malignancy. The disease is classified into several subtypes according to genetic abnormalities. MicroRNAs (miRNAs) are involved in pathological processes (e.g., proliferation, apoptosis, differentiation). A miRNA is a group of short non-coding RNAs with relevant regulatory effects on gene expression achieved by suppression of the translation or degradation of messenger RNA (mRNA). These molecules act as tumor suppressors and/or oncogenes in the pathogenesis of pediatric leukemias. The characteristic features of miRNAs are their stable form and the possibility of secretion to the circulatory system. The role of miRNA in BCP-ALL pathogenesis is still emerging, but several studies have suggested using miRNA expression profiles as biomarkers for diagnosis, prognosis, and response to therapy in leukemia. The dysregulation of some miRNAs involved in childhood acute lymphoid leukemia, such as miR-155, miR-200c, miR-100, miR-181a, miR125b, and miR146a is discussed, showing their possible employment as therapeutic targets. In the current review, the capabilities of miRNAs in non-invasive diagnostics and their prognostic potential as biomarkers are presented.

New Therapeutics for Extracellular Vesicles: Delivering CRISPR for Cancer Treatment

Cancers are defined by genetic defects, which underlines the prospect of using gene therapy in patient care. During the past decade, CRISPR technology has rapidly evolved into a powerful gene editing tool with high fidelity and precision. However, one of the impediments slowing down the clinical translation of CRISPR-based gene therapy concerns the lack of ideal delivery vectors. Extracellular vesicles (EVs) are nano-sized membrane sacs naturally released from nearly all types of cells. Although EVs are secreted for bio-information conveyance among cells or tissues, they have been recognized as superior vectors for drug or gene delivery. Recently, emerging evidence has spotlighted EVs in CRISPR delivery towards cancer treatment. In this review, we briefly introduce the biology and function of the CRISPR system and follow this with a summary of current delivery methods for CRISPR applications. We emphasize the recent progress in EV-mediated CRISPR editing for various cancer types and target genes. The reported strategies for constructing EV-CRISPR vectors, as well as their limitations, are discussed in detail. The review aims to throw light on the clinical potential of engineered EVs and encourage the expansion of our available toolkit to defeat cancer.

miRNA profile at diagnosis predicts treatment outcome in patients with B-chronic lymphocytic leukemia: A FILO study

During many years, chemo-immunotherapy fludarabine-cyclophosphamide-rituximab (FCR) was the gold standard for first line treatment of medically fit patients with symptomatic B-chronic lymphocytic leukemia (CLL). Over the last decade, targeted biotherapies have revolutionized the treatment of B-CLL patients and almost entirely supplanted FCR. However, no biomarker still exists to predict the complete remission (CR) with undetectable minimal residual disease (uMRD) in bone marrow (BM), which remains the best predictive factor for survival. MicroRNAs represent a class of molecular biomarkers which expression is altered in B-CLL. Our study aimed at identifying before treatment blood miRNAs that predict treatment outcome in previously untreated B-CLL patients (NCT 01370772, https://clinicaltrials.gov/ct2/show/NCT01370772). Using hierarchical clustering of miRNA expression profiles discriminating 8 patients who achieved CR with BM uMRD from 8 patients who did not achieve CR and displayed detectable BM MRD, we identified 25 miRNAs differentially expressed before treatment. The expression of 11 miRNAs was further validated on a larger cohort (n=123). Based on the dosage of 5 miRNAs at diagnosis, a decision tree was constructed to predict treatment outcome. We identified 6 groups of patients with a distinct probability of being CR with BM uMRD to FCR treatment, ranging from 72% (miR-125b, miR-15b and miR-181c high) to 4% (miR-125b and miR-193b low). None of the patients displaying high expression levels of miR-125b, miR-15b and miR-181c relapsed during study follow-up. In contrast, patients with low miR-15b and high miR-412, or with low miR-125b and miR-193b, demonstrated significant low PFS. RNA sequencing of blood at diagnosis identified that patients relapsing after treatment are characterized by significant enrichment of gene signatures related to cell cycle, MYC target genes, metabolism and translation regulation. Conversely, patients achieving CR with BM uMRD displayed significant enrichment in genes related to communication between CLL cells and the microenvironment, immune system activation and upregulation of polycomb PRC2 complex target genes. Our results suggest that blood miRNAs are potent predictive biomarkers for FCR treatment efficacy and might be implicated in the FCR efficacy in B-CLL patients, providing new insight into unmet need for the treatment of B-CLL patients and identifying pathways predictive of patients’ remission.

A microRNA signature for clinical outcomes of pediatric ALL patients treated with TPOG protocols

MicroRNA (miRNA) expression is reportedly associated with clinical outcomes in childhood acute lymphoblastic leukemia (ALL). Here, we aimed at investigating whether miRNA expression is associated with clinical outcomes in pediatric ALL patients treated with the Taiwan Pediatric Oncology Group (TPOG) protocols. The expression of 397 miRNAs was measured using stem-loop quantitative real-time polymerase chain reaction miRNA arrays in 60 pediatric ALL patients treated with TPOG-ALL-93 or TPOG-ALL-97 VHR (very high-risk) protocols. In order to identify prognosis-related miRNAs, original cohort was randomly split into the training and testing cohort in a 2:1 ratio, and univariate Cox proportional hazards regression was applied to identify associations between event-free survival (EFS) and expressions of miRNAs. Four prognosis-related miRNAs were selected and validated in another independent cohort composed of 103 patients treated with the TPOG-ALL-2002 protocol. Risk score, including the impact of four prognosis-related miRNAs, was calculated for each patients, followed by grouping patients into the high or low risk-score groups. Irrespective of the training, testing, or validation cohort, risk-score group was significantly associated with EFS and overall survival (OS). Risk-score group combining with clinical characteristics including the age onset (≥10 years), white blood cell counts (≥100 × 10⁹/L), cell type (T- or B-cell), sex, and risk groups of the treatment protocols were used as predictors of EFS using the multivariate Cox proportional hazards regression. Results showed that the risk-score group was the strongest predictor. In the validation cohort, hazard ratios (HRs) of the risk-score group were 7.06 (95% CI=1.93-25.84, p-value =0.003) and 14.03 (95% CI=3.34-59.04, p-value =0.003) for EFS and OS, respectively. High risk-score group had higher risk of having poor prognosis and risk of death than that in the low risk group. Accuracy of the prediction model for 5-year EFS could reach 0.76. For the prediction of 5-year OS, accuracy was 0.75. In conclusion, a miRNA signature was associated with clinical outcomes in childhood ALL patients treated with TPOG protocols and might be a suitable prognostic biomarker.

Expression profile of serum LncRNA THRIL and MiR-125b in inflammatory bowel disease

Background

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract. We aimed to investigate, for the first time, the expression profile of serum level of LncRNA THRIL and MiR-125b in IBD patients and their relations with patient’s clinical and biochemical investigations.

Methods

Our study included 210 subjects divided into 70 healthy subjects considered as control group (male and female), 70 patients with ulcerative colitis (UC), and 70 patients with Crohn’s disease (CD). Blood samples were obtained from all subjects. Expression of LncRNA THRIL and MiR-125b in serum was detected by Quantitative real time PCR (qRT-PCR).

Results

Our results showed a significant increase in the fold change of LncRNA THRIL in UC patients (Median = 11.11, IQR; 10.21–12.45, P<0.001) and CD patients (Median = 5.87, IQR; 4.57–7.88, P<0.001) compared to controls. Meanwhile there was a significant decrease in the fold change of MiR-125b in UC patients (Median = 0.36, IQR; 0.19–0.61, P<0.001) and CD patients (Median = 0.69, IQR; 0.3–0.83, P<0.001) compared to controls. Furthermore, there was a negative significant correlation between LncRNA THRIL and MiR-125b in UC patients (r = -0.28, P = 0.016) and in CD patients (r = -0.772, P<0.001). ROC curve analysis was done showing the diagnostic value of these markers as predictors in differentiating between cases of UC, CD, and control.

Conclusion

Serum LncRNA THRIL and MiR-125b could be used as potential biomarkers for diagnosis and prognosis of ulcerative colitis and Crohn’s disease.

microRNA expression in acute myeloid leukaemia: New targets for therapy?

Recent studies have shown that short non-coding RNAs, known as microRNAs (miRNAs) and their dysregulation, are implicated in the pathogenesis of acute myeloid leukaemia (AML). This is due to their role in the control of gene expression in a variety of molecular pathways. Therapies involving miRNA suppression and replacement have been developed. The normalisation of expression and the subsequent impact on AML cells have been investigated for some miRNAs, demonstrating their potential to act as therapeutic targets. Focussing on miRs with therapeutic potential, we have reviewed those that have a significant impact on the aberrant biological processes associated with AML, and crucially, impact leukaemic stem cell survival. We describe six miRNAs in preclinical trials (miR-21, miR-29b, miR-126, miR-181a, miR-223 and miR-196b) and two miRNAs that are in clinical trials (miR-29 and miR-155). However none have been used to treat AML patients and greater efforts are needed to develop miRNA therapies that could benefit AML patients in the future.

Molecular mechanisms and clinical applications of exosomes in prostate cancer

Prostate cancer (PC) is a common tumor in men, and the incidence rate is high worldwide. Exosomes are nanosized vesicles released by all types of cells into multiple biological fluid types. These vesicles contribute to intercellular communication by delivering both nucleic acids and proteins to recipient cells. In recent years, many studies have explored the mechanisms by which exosomes mediate the epithelial-mesenchymal transition, angiogenesis, tumor microenvironment establishment, and drug resistance acquisition in PC, and the mechanisms that have been identified and the molecules involved have provided new perspectives for the possible discovery of novel diagnostic markers in PC. Furthermore, the excellent biophysical properties of exosomes, such as their high stability, high biocompatibility and ability to cross biological barriers, have made exosomes promising candidates for use in novel targeted drug delivery system development. In this review, we summarize the roles of exosomes in the growth and signal transmission in PC and show the promising future of exosome contributions to PC diagnostics and treatment.

Role of Acute Myeloid Leukemia (AML)-Derived exosomes in tumor progression and survival

Acute myeloid leukemia (AML) is a quickly aggressive hematopoietic disorder that progress due to the accumulation and clonal expansion of immature myeloid cells. Despite the latest developments in AML treatment, repeated relapses and drug resistance remain one of the major challenges in treatment of leukemia. Currently, it is well known that the components of the tumor microenvironment such as cellular and non-cellular elements play a critical function in treatment failures of AML, also they are most common cause of complications including suppression of hematopoiesis. Exosomes are membrane-bound extracellular vesicles (EVs) that transfer signaling molecules and have attracted a large amount of attention due to their important role in inter-cellular communication in health and disease. Exosomes participate in the survival and chemoresistance of many leukemia through transferring their rich cargos of molecules including miRNAs, growth factors, and cytokines. The key producers of exosomes that mainly participate to AML pathogenesis are bone marrow mesenchymal stem cell (BMSCs) and AML cell themselves. These cells release an enormous number of exosomes that affect several target cells such as natural killer (NK) and hematopoietic stem cells to the development of leukemia proliferation and progression. In the present study, a comprehensive review of the literature has been done to briefly discuss the biology of exosomes and highlight the role of exosomes derived from AML in the progress of acute myeloid leukemia.

miRNAs in Lymphocytic Leukaemias-The miRror of Drug Resistance

Refractory disease and relapse remain the main causes of cancer therapy failure. Refined risk stratification, treatment regimens and improved early diagnosis and detection of minimal residual disease have increased cure rates in malignancies like childhood acute lymphoblastic leukaemia (ALL) to 90%. Nevertheless, overall survival in the context of drug resistance remains poor. The regulatory role of micro RNAs (miRNAs) in cell differentiation, homeostasis and tumorigenesis has been under extensive investigation in different cancers. There is accumulating data demonstrating the significance of miRNAs for therapy outcomes in lymphoid malignancies and some direct demonstrations of the interplay between these small molecules and drug response. Here, we summarise miRNAs' impact on chemotherapy resistance in adult and paediatric ALL and chronic lymphocytic leukaemia (CLL). The main focus of this review is on the modulation of particular signaling pathways like PI3K-AKT, transcription factors such as NF-κB, and apoptotic mediators, all of which are bona fide and pivotal elements orchestrating the survival of malignant lymphocytic cells. Finally, we discuss the attractive strategy of using mimics, antimiRs and other molecular approaches pointing at miRNAs as promising therapeutic targets. Such novel strategies to circumvent ALL and CLL resistance networks may potentially improve patients' responses and survival rates.

MicroRNAs in Leukemias: A Clinically Annotated Compendium

Leukemias are a group of malignancies of the blood and bone marrow. Multiple types of leukemia are known, however reliable treatments have not been developed for most leukemia types. Furthermore, even relatively reliable treatments can result in relapses. MicroRNAs (miRNAs) are a class of short, noncoding RNAs responsible for epigenetic regulation of gene expression and have been proposed as a source of potential novel therapeutic targets for leukemias. In order to identify central miRNAs for leukemia, we conducted data synthesis using two databases: miRTarBase and DISNOR. A total of 137 unique miRNAs associated with 16 types of leukemia were retrieved from miRTarBase and 86 protein-coding genes associated with leukemia were retrieved from the DISNOR database. Based on these data, we formed a visual network of 248 miRNA-target interactions (MTI) between leukemia-associated genes and miRNAs associated with ≥4 leukemia types. We then manually reviewed the literature describing these 248 MTIs for interactions identified in leukemia studies. This manually curated data was then used to visualize a network of 64 MTIs identified in leukemia patients, cell lines and animal models. We also formed a visual network of miRNA-leukemia associations. Finally, we compiled leukemia clinical trials from the ClinicalTrials database. miRNAs with the highest number of MTIs were miR-125b-5p, miR-155-5p, miR-181a-5p and miR-19a-3p, while target genes with the highest number of MTIs were TP53, BCL2, KIT, ATM, RUNX1 and ABL1. The analysis of 248 MTIs revealed a large, highly interconnected network. Additionally, a large MTI subnetwork was present in the network visualized from manually reviewed data. The interconnectedness of the MTI subnetwork suggests that certain miRNAs represent central disease molecules for multiple leukemia types. Additional studies on miRNAs, their target genes and associated biological pathways are required to elucidate the therapeutic potential of miRNAs in leukemia.

The megakaryocytic transcription factor ARID3A suppresses leukemia pathogenesis

Given the plasticity of hematopoietic stem and progenitor cells, multiple routes of differentiation must be blocked in the the pathogenesis of acute myeloid leukemia, the molecular basis of which is incompletely understood. We report that posttranscriptional repression of the transcription factor ARID3A by miR-125b is a key event in the pathogenesis of acute megakaryoblastic leukemia (AMKL). AMKL is frequently associated with trisomy 21 and GATA1 mutations (GATA1s), and children with Down syndrome are at a high risk of developing the disease. The results of our study showed that chromosome 21-encoded miR-125b synergizes with Gata1s to drive leukemogenesis in this context. Leveraging forward and reverse genetics, we uncovered Arid3a as the main miR-125b target behind this synergy. We demonstrated that, during normal hematopoiesis, this transcription factor promotes megakaryocytic differentiation in concert with GATA1 and mediates TGFβ-induced apoptosis and cell cycle arrest in complex with SMAD2/3. Although Gata1s mutations perturb erythroid differentiation and induce hyperproliferation of megakaryocytic progenitors, intact ARID3A expression assures their megakaryocytic differentiation and growth restriction. Upon knockdown, these tumor suppressive functions are revoked, causing a blockade of dual megakaryocytic/erythroid differentiation and subsequently of AMKL. Inversely, restoring ARID3A expression relieves the arrest of megakaryocytic differentiation in AMKL patient-derived xenografts. This work illustrates how mutations in lineage-determining transcription factors and perturbation of posttranscriptional gene regulation can interact to block multiple routes of hematopoietic differentiation and cause leukemia. In AMKL, surmounting this differentiation blockade through restoration of the tumor suppressor ARID3A represents a promising strategy for treating this lethal pediatric disease.

Microenvironment and drug resistance in acute myeloid leukemia: Do we know enough?

Acute myeloid leukemia (AMLs), as the name suggests, often develop suddenly and are very progressive forms of cancer. Unlike in acute promyelocytic leukemia, a subtype of AML, the outcomes in most other AMLs remain poor. This is mainly attributed to the acquired drug resistance and lack of targeted therapy. Different studies across laboratories suggest that the cellular mechanisms to impart therapy resistance are often very dynamic and should be identified in a context-specific manner. Our review highlights the progress made so far in identifying the different cellular mechanisms of mutation-independent therapy resistance in AML. It reiterates that for more effective outcomes cancer therapies should acquire a more tailored approach where the protective interactions between the cancer cells and their niches are identified and targeted.

Hyperleukocytic Acute Leukemia Circulating Exosomes Regulate HSCs and BM-MSCs

Hyperleukocytic acute leukemia (HLAL) circulating exosomes are delivered to hematopoietic stem cells (HSCs) and bone marrow mesenchymal stem cells (BM-MSCs), thereby inhibiting the normal hematopoietic process. In this paper, we have evaluated and explored the effects of miR-125b, which is carried by HLAL-derived exosomes, on the hematopoietic function of HSCs and BM-MSCs. For this purpose, we have isolated exosomes from the peripheral blood of HLAL patients and healthy volunteers. Then, we measured the level of miR-125b in exosomes cocultured exosomes with HSCs and BM-MSCs. Moreover, we have used miR-125b inhibitors/mimic for intervention and then measured miR-125b expression and colony forming unit (CFU). Apart from it, HSC and BM-MSC hematopoietic-related factors α-globulin, γ-globulin, CSF2, CRTX4 and CXCL12, SCF, IGF1, and DKK1 expression were measured. Evaluation of the miR-125b and BAK1 targeting relationship, level of miR-125b, and expression of hematopoietic-related genes was performed after patients are treated with miR-125b mimic and si-BAK1. We have observed that miR-125b was upregulated in HLAL-derived exosomes. After HLAL-exosome acts on HSCs, the level of miR-125b is upregulated, reducing CFU and affecting the expression of α-globulin, γ-globulin, CSF2, and CRCX4. For BM-MSCs, after the action of HLAL-exo, the level of miR-125b is upregulated and affected the expression of CXCL12, SCF, IGF1, and DKK1. Exosomes derived from HLAL carry miR-125b to target and regulate BAK1. Further study confirmed that miR-125b and BAK1mimic reduced the expression of miR-125b and reversed the effect of miR-125b mimic on hematopoietic-related genes. These results demonstrated that HLAL-derived exosomes carrying miR-125b inhibit the hematopoietic differentiation of HSC and hematopoietic support function of BM-MSC through BAK1.

Regulatory noncoding RNAs: potential biomarkers and therapeutic targets in acute myeloid leukemia

The noncoding RNAs (ncRNA) comprise a substantial segment of the human transcriptome and have emerged as key elements of cellular homeostasis and disease pathogenesis. Dysregulation of these ncRNAs by alterations in the primary RNA motifs and/or aberrant expression levels is relevant in various diseases, especially cancer. The recent research advances indicate that ncRNAs regulate vital oncogenic processes, including hematopoietic cell differentiation, proliferation, apoptosis, migration, and angiogenesis. The ever-expanding role of ncRNAs in cancer progression and metastasis has sparked interest as potential diagnostic and prognostic biomarkers in acute myeloid leukemia. Moreover, advances in antisense oligonucleotide technologies and pharmacologic discoveries of small molecule inhibitors in targeting RNA structures and RNA-protein complexes have opened newer avenues that may help develop the next generation anti-cancer therapeutics. In this review, we have discussed the role of ncRNA in acute myeloid leukemia and their utility as potential biomarkers and therapeutic targets.

Extracellular Vesicles in Acute Leukemia: A Mesmerizing Journey With a Focus on Transferred microRNAs

Despite their small size, the membrane-bound particles named extracellular vesicles (EVs) seem to play an enormous role in the pathogenesis of acute leukemia. From oncogenic hematopoietic stem cells (HSCs) to become leukemic cells to alter the architecture of bone marrow (BM) microenvironment, EVs are critical components of leukemia development. As a carrier of essential molecules, especially a group of small non-coding RNAs known as miRNA, recently, EVs have attracted tremendous attention as a prognostic factor. Given the importance of miRNAs in the early stages of leukemogenesis and also their critical parts in the development of drug-resistant phenotype, it seems that the importance of EVs in the development of leukemia is more than what is expected. To be familiar with the clinical value of leukemia-derived EVs, this review aimed to briefly shed light on the biology of EVs and to discuss the role of EV-derived miRNAs in the development of acute myeloid leukemia and acute lymphoblastic leukemia. By elaborating the advances and challenges concerning the isolation of EVs, we discuss whether EVs could have a prognostic value in the clinical setting for leukemia.

MicroRNA‑93 knockdown inhibits acute myeloid leukemia cell growth via inactivating the PI3K/AKT pathway by upregulating DAB2

Acute myeloid leukemia (AML) is associated with a poor prognosis in elderly adults and currently lacks optimal treatment strategies. MicroRNAs (miRNAs or miRs) have increasingly been reported to be associated with AML progression; however, the mechanisms of action of miR-93 in AML with the involvement of disabled 2 (DAB2) are currently unknown. In the present study, miR-93 expression was assessed in patients with AML and in AML cell lines. The association between miR-93 expression and the pathological characteristics of patients with AML was analyzed. AML cells were then transfected to knockdown or overexpress miR-93 in order to elucidate its function in AML progression. The target gene of miR-93 was assessed using a dual-luciferase reporter gene assay. The expression levels of miR-93, DAB2 and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway-related proteins were measured and in vivo experiments were conducted to confirm the results. It was observed that miR-93 was highly expressed in patients with AML and in AML cells. The knockdown of miR-93 in HL-60 cells inhibited AML cell proliferation and resistance to apoptosis, while the overexpression of miR-93 in THP-1 cells led to contrasting results. Moreover, miR-93 targeted DAB2 to inactivate the PI3K/AKT pathway, and the overexpression of DAB2 reversed the effects of miR-93 on THP-1 cell growth. Tumor volume, tumor weight, and the positive expression of Ki67, survivin and p53 were increased in THP-1 cells overexpressing miR-93. On the whole, the present study demonstrates that miR-93 is highly expressed in AML cells, and that the suppression of miR-93 inhibits AML cell growth by targeting DAB2 and inhibiting the PI3K/AKT pathway.

Circulating MicroRNAs in Small-bowel Neuroendocrine Tumors: A Potential Tool for Diagnosis and Assessment of Effectiveness of Surgical Resection

OBJECTIVE

To discover serum-based microRNA (miRNA) biomarkers for small-bowel neuroendocrine tumors (SBNET) to help guide clinical decisions.

BACKGROUND

MiRNAs are small noncoding RNA molecules implicated in the initiation and progression of many cancers. MiRNAs are remarkably stable in bodily fluids, and can potentially be translated into clinically useful biomarkers. Novel biomarkers are needed in SBNET to determine disease aggressiveness, select patients for treatment, detect early recurrence, and monitor response.

METHODS

This study was performed in 3 stages (discovery, validation, and a prospective, longitudinal assessment). Discovery comprised of global profiling of 376 miRNA in sera from SBNET patients (n = 11) versus healthy controls (HCs; n = 3). Up-regulated miRNAs were subsequently validated in additional SBNET (n = 33) and HC sera (n = 14); and then longitudinally after SBNET resection (n = 12), with serial serum sampling (preoperatively day 0; postoperatively at 1 week, 1 month, and 12 months).

RESULTS

Four serum miRNAs (miR-125b-5p, -362-5p, -425-5p and -500a-5p) were significantly up-regulated in SBNET (P < 0.05; fold-change >2) based on multiple normalization strategies, and were validated by RT-qPCR. This combination was able to differentiate SBNET from HC with an area under the curve of 0.951. Longitudinal assessment revealed that miR-125b-5p returned towards HC levels at 1 month postoperatively in patients without disease, whereas remaining up-regulated in those with residual disease (RSD). This was also true at 12 months postoperatively. In addition, miR-362-5p appeared up-regulated at 12 months in RSD and recurrent disease (RCD).

CONCLUSIONS

Our study represents the largest global profiling of serum miRNAs in SBNET patients, and the first to evaluate ongoing serum miRNA expression changes after surgical resection. Serum miR-125b-5p and miR-362-5p have potential to be used to detect RSD/RCD.

Slow transcription of the 99a/let-7c/125b-2 cluster results in differential miRNA expression and promotes melanoma phenotypic plasticity

Almost half of human miRNAs are encoded in clusters. Although transcribed as a single unit, the levels of individual mature miRNAs often differ. The mechanisms underlying differential biogenesis of clustered miRNAs and the resulting physiological implications are mostly unknown. Here, we report that the melanoma master transcription regulator MITF regulates the differential expression of the 99a/let-7c/125b-2 cluster by altering the distribution of RNA polymerase II (Pol-II) along the cluster. We discovered that MITF interacts with TRIM28, a known inhibitor of Pol-II transcription elongation, at the let-7c region resulting in Pol-II pausing and causing its elevated expression, whereas low levels of Pol-II occupation over miR-99a and miR-125b-2 regions decreases their biogenesis. Furthermore, we showed that this differential expression affects the phenotypic state of melanoma cells. RNA-seq analysis of proliferative melanoma cells that express miR-99a and miR-125b mimics revealed a transcriptomic shift toward an invasive phenotype. Conversely, expression of a let-7c mimic in invasive melanoma cells induced a shift to a more proliferative state. We confirmed direct target genes of these miRNAs: FGFR3, BAP1, Bcl2, TGFBR1, and CDKN1A. Our study demonstrates a MITF-governed biogenesis mechanism that results in differential expression of clustered 99a/let-7c/125b-2 miRNAs that control melanoma progression.

B-cell acute lymphoblastic leukemia-related microRNAs: uncovering their diverse and special roles

B-cell acute lymphoblastic leukemia (B-ALL) is a common type of hematologic malignancy characterized by the uncontrolled growth of immature B lymphocytes. Genomics, transcriptomics, and proteomics at different levels contribute to early diagnosis and can thereby provide better treatment for cancer. MicroRNAs (miRNAs) are conducive to the diagnosis and treatment of patients with B-ALL. Moreover, evidence suggests that runaway miRNAs and exosomes containing miRNA may be involved in the occurrence of B-ALL, which can then be used as potential biomarkers. This review summarizes the role of miRNAs in the pathogenesis, diagnosis, prognosis, and treatment of B-ALL.

Non-Coding RNA Signatures of B-Cell Acute Lymphoblastic Leukemia

Non-coding RNAs (ncRNAs) comprise a diverse class of non-protein coding transcripts that regulate critical cellular processes associated with cancer. Advances in RNA-sequencing (RNA-Seq) have led to the characterization of non-coding RNA expression across different types of human cancers. Through comprehensive RNA-Seq profiling, a growing number of studies demonstrate that ncRNAs, including long non-coding RNA (lncRNAs) and microRNAs (miRNA), play central roles in progenitor B-cell acute lymphoblastic leukemia (B-ALL) pathogenesis. Furthermore, due to their central roles in cellular homeostasis and their potential as biomarkers, the study of ncRNAs continues to provide new insight into the molecular mechanisms of B-ALL. This article reviews the ncRNA signatures reported for all B-ALL subtypes, focusing on technological developments in transcriptome profiling and recently discovered examples of ncRNAs with biologic and therapeutic relevance in B-ALL.

The lncRNA XIST/miR-125b-2-3p axis modulates cell proliferation and chemotherapeutic sensitivity via targeting Wee1 in colorectal cancer

Background

Numerous reports on microRNAs have illustrated their role in tumor growth and metastasis. Recently, a new prognostic factor, miR‐125b‐2‐3p, has been identified for predicting chemotherapeutic sensitivity in advanced colorectal cancer (CRC). However, the specific mechanisms and biological functions of miR‐125b‐2‐3p in advanced CRC under chemotherapy have yet to be elucidated.

Methods

MiR‐125b‐2‐3p expression was detected by real‐time PCR (RT‐PCR) in CRC tissues. The effects of miR‐125b‐2‐3p on the growth, metastasis, and drug sensitivity of CRC cells were tested in vitro and in vivo. Based on multiple databases, the upstream competitive endogenous RNAs (ceRNAs) and the downstream genes for miR‐125b‐2‐3p were predicted by bioinformatic analysis, followed by the experiments including luciferase reporter assays, western blot assays, and so on.

Results

MiR‐125b‐2‐3p was significantly lowly expressed in the tissues and cell lines of CRC. Higher expression of miR‐125b‐2‐3p was associated with relatively lower proliferation rates and fewer metastases. Moreover, overexpressed miR‐125b‐2‐3p remarkably improved chemotherapeutic sensitivity of CRC in vivo and in vitro. Mechanistically, miR‐125b‐2‐3p was absorbed by long noncoding RNA (lncRNA) XIST regulating WEE1 G2 checkpoint kinase (WEE1) expression. The upregulation of miR‐125b‐2‐3p inhibited the proliferation and epithelial‐mesenchymal transition (EMT) of CRC induced by lncRNA XIST.

Conclusions

Lower miR‐125b‐2‐3p expression resulted in lower sensitivity of CRC to chemotherapy and was correlated with poorer survival of CRC patients. LncRNA XIST promoted CRC metastasis acting as a ceRNA for miR‐125b‐2‐3p to mediate WEE1 expression. LncRNA XIST‐miR‐125b‐2‐3p‐WEE1 axis not only regulated CRC growth and metastasis but also contributed to chemotherapeutic resistance to CRC.

A novel leukemic route of mutant NPM1 through nuclear import of the overexpressed long noncoding RNA LONA

The most frequent genetic alteration in acute myeloid leukemia (AML) is the mutation of nucleophosmin 1 (NPM1). Yet, its downstream oncogenic routes are not fully understood. Here, we report the identification of one long noncoding RNA (lncRNA) overexpressed in NPM1-mutated AML patients (named LONA) whose intracellular localization inversely reflects that of NPM1. While NPM1 is nuclear and LONA cytoplasmic in wild-type NPM1 AML cells, LONA becomes nuclear as mutant NPM1 moves toward the cytoplasm. Gain or loss of function combined with a genome-wide RNA-seq search identified a set of LONA mRNA targets encoding proteins involved in myeloid cell differentiation (including THSB1, MAFB, and ASB2) and interaction with its microenvironment. Consistently, LONA overexpression in mutant NPM1 established cell lines and primary AML cells exerts an anti-myeloid differentiation effect, whilst it exerts an opposite pro-myeloid differentiation effect in a wild type NPM1 setting. In vivo, LONA overexpression acts as an oncogenic lncRNA reducing the survival of mice transplanted with AML cells and rendering AML tumors more resistant to AraC chemotherapy.These data indicate that mutation-dependent nuclear export of NPM1 leads to nuclear retention and consequent oncogenic functions of the overexpressed lncRNA LONA, thus uncovering a novel NPM1 mutation-dependent pathway in AML pathogenesis.

Non-Coding RNAs as Mediators of Epigenetic Changes in Malignancies

Non-coding RNAs (ncRNAs) are untranslated RNA molecules that regulate gene expressions. NcRNAs include small nuclear RNAs (snRNAs), small nucleolar RNAs (snoRNAs), ribosomal RNAs (rRNAs), transfer RNAs (tRNAs), circular RNAs (cRNAs) and piwi-interacting RNAs (piRNAs). This review focuses on two types of ncRNAs: microRNAs (miRNAs) or short interfering RNAs (siRNAs) and long non-coding RNAs (lncRNAs). We highlight the mechanisms by which miRNAs and lncRNAs impact the epigenome in the context of cancer. Both miRNAs and lncRNAs have the ability to interact with numerous epigenetic modifiers and transcription factors to influence gene expression. The aberrant expression of these ncRNAs is associated with the development and progression of tumors. The primary reason for their deregulated expression can be attributed to epigenetic alterations. Epigenetic alterations can cause the misregulation of ncRNAs. The experimental evidence indicated that most abnormally expressed ncRNAs impact cellular proliferation and apoptotic pathways, and such changes are cancer-dependent. In vitro and in vivo experiments show that, depending on the cancer type, either the upregulation or downregulation of ncRNAs can prevent the proliferation and progression of cancer. Therefore, a better understanding on how ncRNAs impact tumorigenesis could serve to develop new therapeutic treatments. Here, we review the involvement of ncRNAs in cancer epigenetics and highlight their use in clinical therapy.

The Impact of Adipose Tissue-Derived miRNAs in Metabolic Syndrome, Obesity, and Cancer

Obesity is a multifactorial and complex condition that is characterized by abnormal and excessive white adipose tissue accumulation, which can lead to the development of metabolic diseases, such as type 2 diabetes mellitus, nonalcoholic fatty liver disease, cardiovascular diseases, and several types of cancer. Obesity is characterized by excessive adipose tissue accumulation and associated with alterations in immunity, displaying a chronic low-grade inflammation profile. Adipose tissue is a dynamic and complex endocrine organ composed not only by adipocytes, but several immunological cells, which can secrete hormones, cytokines and many other factors capable of regulating metabolic homeostasis and several critical biological pathways. Remarkably, adipose tissue is a major source of circulating microRNAs (miRNAs), recently described as a novel form of adipokines. Several adipose tissue-derived miRNAs are deeply associated with adipocytes differentiation and have been identified with an essential role in obesity-associated inflammation, insulin resistance, and tumor microenvironment. During obesity, adipose tissue can completely change the profile of the secreted miRNAs, influencing circulating miRNAs and impacting the development of different pathological conditions, such as obesity, metabolic syndrome, and cancer. In this review, we discuss how miRNAs can act as epigenetic regulators affecting adipogenesis, adipocyte differentiation, lipid metabolism, browning of the white adipose tissue, glucose homeostasis, and insulin resistance, impacting deeply obesity and metabolic diseases. Moreover, we characterize how miRNAs can often act as oncogenic and tumor suppressor molecules, significantly modulating cancer establishment and progression. Furthermore, we highlight in this manuscript how adipose tissue-derived miRNAs can function as important new therapeutic targets.

Investigating the expressions of miRNA-125b and TP53 in endometriosis. Does it underlie cancer-like features of endometriosis? A case-control study

BACKGROUND

Endometriosis is generally considered as a benign condition; however, there is a possibility for it to become cancerous. miR-125b is upregulated in both endometriotic tissues and serum samples of women with endometriosis but its potential targets in endometriosis are still not fully understood.

OBJECTIVE

The role of miR-125b in the regulation of TP53 expression in endometriosis was tested with a bioinformatics approach. In addition, the expression of miR-125b and TP53 in both eutopic (Eu-p) and ectopic endometrium (Ec-p) in the endometrium tissues of women with endometriosis was compared to those in the normal endometrium tissues of controls (Normal).

MATERIALS AND METHODS

In this case-control study, the Eu-p and Ec-p samples were collected from 20 women who underwent laparoscopic surgery, and the normal endometrium tissues were collected from 20 controls with no evidence of endometriosis. For bioinformatics approach, a protein-protein interaction network was constructed based on co-expressed potential targets of miR-125b. Quantitative polymerase chain reaction technique was used for the measurement of miR125b and TP53 expression.

RESULTS

Our results showed that miR-125b was significantly overexpressed in Ec-p (p-value: 0.021). In addition, there was a significant TP53 under expression in both the Ec-p and Eu-p samples compared with the Normal tissues (p-value: 0.003).

CONCLUSION

The negative correlation between miR-125b and TP53 as well as a noticeable decreased expression of TP53 in both Ec-p and Eu-p samples may be interpreted as the roles of miR-125b/TP53 axis in the pathogenesis of endometriosis. In addition, these findings and bioinformatic analyses imply a possible role of miR-125b in cancer-like features of endometriosis.

MicroRNA‑145 promotes the apoptosis of leukemic stem cells and enhances drug‑resistant K562/ADM cell sensitivity to adriamycin via the regulation of ABCE1

Leukemia is a type of cancer which originates in blood-forming tissues. MicroRNAs (miRNAs or miRs) have been shown to be involved leukemogenesis. In the present study, following the gain- and loss-function of miR-145 and ATP-binding cassette sub-family E member 1 (ABCE1) in K562 cells and K562 adriamycin-resistant cells (K562/ADM cells), the levels of multidrug resistance protein 1 (MRP1) and P-glycoprotein (P-gp) were measured. The viability of the K562 cells and K562/ADM cells treated with various concentrations of ADM, and cell sensitivity to ADM were measured. The apoptosis of stem cells was detected. K562/ADM cells were transfected with miR-145 mimic or with miR-145 mimic together with ABCE1 overexpression plasmid to examine the effects of ABCE1 on the sensitivity of K562/ADM cells to ADM. The association between miR-145 and ABCE1/MRP1 was then verified. The dose- and time-dependent effects of ADM on the K562 cells and K562/ADM cells were examined. The K562/ADM cells exhibited a greater resistance to ADM, higher levels of MRP1 and P-gp, and a lower miR-145 expression. The K562/ADM cells and stem cells in which miR-145 was overexpressed exhibited a suppressed cell proliferation, decreased MRP1 and P-gp levels, and an increased apoptotic rate. However, K562 cells with a low expression of miR-145 exhibited an increased cell proliferation, increased levels of MRP1 and P-gp, and a suppressed apoptotic rate. Compared with the overexpression of miR-145, the combination of miR-145 and ABCE1 decreased the sensitivity of drug-resistant K562/ADM cells to ADM. The above-mentioned effects of miR-145 were achieved by targeting ABCE1. Taken together, the findings of the present study demonstrate that the overexpression of miR-145 promotes leukemic stem cell apoptosis and enhances the sensitivity of K562/ADM cells to ADM by inhibiting ABCE1.

Role of microRNA dysregulation in childhood acute leukemias: Diagnostics, monitoring and therapeutics: A comprehensive review

MicroRNAs (miRNAs) are short noncoding RNAs that regulate the expression of genes by sequence-specific binding to mRNA to either promote or block its translation; they can also act as tumor suppressors (e.g., let-7b, miR-29a, miR-99, mir-100, miR-155, and miR-181) and/or oncogenes (e.g., miR-29a, miR-125b, miR-143-p3, mir-155, miR-181, miR-183, miR-196b, and miR-223) in childhood acute leukemia (AL). Differentially expressed miRNAs are important factors associated with the initiation and progression of AL. As shown in many studies, they can be used as noninvasive diagnostic and prognostic biomarkers, which are useful in monitoring early stages of AL development or during therapy (e.g., miR-125b, miR-146b, miR-181c, and miR-4786), accurate classification of different cellular or molecular AL subgroups (e.g., let-7b, miR-98, miR-100, miR-128b, and miR-223), and identification and development of new therapeutic agents (e.g., mir-10, miR-125b, miR-203, miR-210, miR-335). Specific miRNA patterns have also been described for commonly used AL therapy drugs (e.g., miR-125b and miR-223 for doxorubicin, miR-335 and miR-1208 for prednisolone, and miR-203 for imatinib), uncovering miRNAs that are associated with treatment response. In the current review, the role of miRNAs in the development, progression, and therapy monitoring of pediatric ALs will be presented and discussed.

Relationship between Sphk1/S1P and microRNAs in human cancers

Sphingosine kinases type 1 (SphK1) is a key enzyme in the phosphorylation of sphingosine to sphingosine 1-phosphate (S1P). Different abnormalities in SphK1 functions may correspond with poor prognosis in various cancers. Additionally, upregulated SphK1/S1P could promote cancer cell proliferation, angiogenesis, mobility, invasion, and metastasis. MicroRNAs as conserved small noncoding RNAs play major roles in cancer initiation, progression, metastasis, etc. Their posttranscriptionally mechanisms could affect the development of cancer growth or tumorigenesis suppression. The growing number of studies has described that various microRNAs can be regulated by SphK1, and its expression level can also be regulated by microRNAs. In this review, the relationship of SphK1 and microRNA functions and their interaction in human malignancies have been discussed. Based on them novel treatment strategies can be introduced.

MicroRNA-125b as a tumor suppressor by targeting MMP11 in breast cancer

Background

Breast cancer is a common type of tumor in women worldwide. MicroRNAs have been identified as regulators in many human cancers. The aim of this study was therefore to investigate the functional role of miR‐125b in regulating breast cancer progression.

Methods

We used the StarBase database to investigate the expression of miRNA‐125b in breast cancer and adjacent normal tissues. MMP11 3′‐UTR construct and luciferase reporter assays was performed for target genes. Cell proliferation was evaluated by CCK‐8 and colony formation assay. The migration and invasion were assessed by transwell assay.

Results

Luciferase reporter assays showed miRNA‐125b directly targeted MMP11. miRNA‐125b by transfection with its mimic in breast cancer cells significantly suppressed breast cancer cell proliferation and migration. Western blot revealed that overexpression of miRNA‐125b substantially reduced MMP11 protein expression. We used the UALCAN database to investigate the expression of MMP11 in human breast cancer and adjacent normal tissues. In addition, we found that miRNA‐125b spoiled MMP11 induced breast cancer cell proliferation and migration promotion effect.

Conclusions

miRNA‐125b mimic inhibited proliferation, migration, and invasion of breast cancer cells through targeting MMP11 protein.

Improved Antitumor Efficacy of Chimeric Antigen Receptor T Cells that Secrete Single-Domain Antibody Fragments

Chimeric antigen receptor (CAR) T-cell therapy is effective in the treatment of cancers of hematopoietic origin. In the immunosuppressive solid tumor environment, CAR T cells encounter obstacles that compromise their efficacy. We developed a strategy to address these barriers by having CAR T cells secrete single-domain antibody fragments [variable heavy domain of heavy chain antibodies (VHH) or nanobodies] that can modify the intratumoral immune landscape and thus support CAR T-cell function in immunocompetent animals. VHHs are small in size and able to avoid domain swapping when multiple nanobodies are expressed simultaneously-features that can endow CAR T cells with desirable properties. The secretion of an anti-CD47 VHH by CAR T cells improves engagement of the innate immune system, enables epitope spreading, and can enhance the antitumor response. CAR T cells that secrete anti-PD-L1 or anti-CTLA-4 nanobodies show improved persistence and demonstrate the versatility of this approach. Furthermore, local delivery of secreted anti-CD47 VHH-Fc fusions by CAR T cells at the tumor site limits their systemic toxicity. CAR T cells can be further engineered to simultaneously secrete multiple modalities, allowing for even greater tailoring of the antitumor immune response.

microRNA and Metabolite Signatures Linked to Early Consequences of Lethal Radiation

Lethal total body irradiation (TBI) triggers multifactorial health issues in a potentially short time frame. Hence, early signatures of TBI would be of great clinical value. Our study aimed to interrogate microRNA (miRNA) and metabolites, two biomolecules available in blood serum, in order to comprehend the immediate impacts of TBI. Mice were exposed to a lethal dose (9.75 Gy) of Cobalt-60 gamma radiation and euthanized at four time points, namely, days 1, 3, 7 and 9 post-TBI. Serum miRNA libraries were sequenced using the Illumina small RNA sequencing protocol, and metabolites were screened using a mass spectrometer. The degree of early impacts of irradiation was underscored by the large number of miRNAs and metabolites that became significantly expressed during the Early phase (day 0 and 1 post-TBI). Radiation-induced inflammatory markers for bone marrow aplasia and pro-sepsis markers showed early elevation with longitudinal increment. Functional analysis integrating miRNA-protein-metabolites revealed inflammation as the overarching host response to lethal TBI. Early activation of the network linked to the synthesis of reactive oxygen species was associated with the escalated regulation of the fatty acid metabolism network. In conclusion, we assembled a list of time-informed critical markers and mechanisms of significant translational potential in the context of a radiation exposure event.

Tissue microRNAs in non-small cell lung cancer detected with a new kind of liquid bead array detection system

Background

Commonly used miRNA detection methods cannot be applied for high-throughput analyses. However, this study was aimed to performed a liquid bead array detection system (LBAS) to detect tissue 6 miRNAs in non-small cell lung cancer (NSCLC).

Methods

In this study, evaluation of LBAS was performed to observe the precision, specificity, limitation and stability. Then, a total of 52 primary NSCLC patients who received resection operation without preoperative radiotherapy and chemotherapy between June 2013 and March 2014 were selected, and then the total RNA of the tissues were extracted. We prepared six NSCLC-related miRNAs for LBAS. After optimization and evaluation, LBAS was verified by detecting the relative expression levels of 6 microRNAs in the pathological tissues and corresponding normal tissues of 52 NSCLC patients.

Results

The results of evaluation of LBAS showed that the Mean Fluorescence Intensity (MFI) of the reaction only added with chimeric probes and beads showed no significant change after 180 days (P > 0.05). And the intra-assay Coefficient of Variation (CV) was between 1.57 and 3.5%, while the inter-assay CV was between 4.24 and 11.27%, indicating this system was ideal for diagnostic reagents. In addition, only the beads corresponding to the additional miRNAs showed high MFIs from 8426 to 18,769, whereas the fluorescence values of the other beads were under background levels (MFIs = 20 to 55) in each reaction, indicating no cross reactivity among the miRNAs. The limit of detection of miR-21, miR-210, miR-125b, miR-155, miR-375, and miR-31 were 5.27, 1.39, 1.85, 2.01, 1.34, and 2.73 amol/μL, respectively, showing that the lowest detection limit of miRNA by this system was under pM level. Then, the relative expression levels of miR-21, miR-210, miR-125b, miR-155, miR-375, and miR-31 by using this system were significantly correlated with NSCLC (P < 0.05). And the results of AUC method indicated that specific of the LBAS system was 94.2%.

Conclusions

Our findings suggest that LBAS was simple, high-throughput, and freely combined with absolute quantification. Thus, this system could be applied for tumor miRNAs detection.

Overview of current microRNA biomarker signatures as potential diagnostic tools for leukaemic conditions

Haematological malignancies encompass all variations of leukaemia at both the chronic and acute level, together with the specific cell type induced into tumourigenesis. Current diagnostic protocols for leukaemic conditions rely heavily on cytomorphology and other histological examinations from bone marrow aspirates, with the latter being a highly invasive surgical procedure for the patient. The discovery of microRNAs as one of the key gene regulatory networks in the past two decades has enabled researchers to investigate the possibility of exploiting the identification of dysregulated expression profiles for specific microRNAs present in the leukaemic patient's bloodstream as novel liquid biopsy diagnostic tools. This review article serves to consolidate recent global research efforts aiming to achieve such scopes.

MicroRNA profiling in canine multicentric lymphoma

Lymphoma is the most common hematopoietic tumour in dogs and is remarkably similar to the human disease. Tumour biomarker discovery is providing new tools for diagnostics and predicting therapeutic response and clinical outcome. MicroRNAs are small non-coding RNAs that participate in post-transcriptional gene regulation and their aberrant expression can impact genes involved in cancer. The aim of this study was to characterize microRNA expression in lymph nodes and plasma from dogs with multicentric B or T cell lymphoma compared to healthy control dogs. We further compared expression between lymph nodes and corresponding plasma samples and assessed changes in expression at relapse compared to time of diagnosis. Lastly, we investigated microRNAs for association with clinical outcome in patients treated with CHOP chemotherapy. A customized PCR array was utilized to profile 38 canine target microRNAs. Quantification was performed using real time RT-qPCR and relative expression was determined by the delta-delta Ct method. In lymph nodes, there were 16 microRNAs with significantly altered expression for B cell lymphoma and 9 for T cell lymphoma. In plasma, there were 15 microRNAs altered for B cell lymphoma and 3 for T cell lymphoma. The majority of microRNAs did not have correlated expression between lymph node and plasma and only 8 microRNAs were significantly different between diagnosis and relapse. For B cell lymphoma, 8 microRNAs had differential expression in the non-remission group compared to dogs that completed CHOP in complete remission. Four of these microRNAs were also altered in patients that died prior to one-year. Kaplan-Meier survival curves for high versus low microRNA expression revealed that 10 microRNAs were correlated with progression-free survival and 3 with overall survival. This study highlights microRNAs of interest for canine multicentric lymphoma. Future goals include development of microRNA panels that may be useful as biomarkers with the intent to provide improved outcome prediction to veterinary cancer patients.

Immune-Related Circulating miR-125b-5p and miR-99a-5p Reveal a High Recurrence Risk Group of Pancreatic Cancer Patients after Tumor Resection

Clinical follow-up aided by changes in the expression of circulating microRNAs (miRs) may improve prognostication of pancreatic ductal adenocarcinoma (PDAC) patients. Changes in 179 circulating miRs due to cancer progression in the transgenic Kras G12D/+; Trp53 R172H/+; P48-Cre (KPC) animal model of PDAC were analyzed for serum miRs that are altered in metastatic disease. In addition, expression levels of 250 miRs were profiled before and after pancreaticoduodenectomy in the serum of two patients with resectable PDAC with different progression free survival (PFS) and analyzed for changes indicative of PDAC recurrence after resection. Three miRs that were upregulated ≥3-fold in progressive PDAC in both mice and patients were selected for validation in 26 additional PDAC patients before and after resection. We found that high serum miR-125b-5p and miR-99a-5p levels after resection are significantly associated with shorter PFS (HR 1.34 and HR 1.73 respectively). In situ hybridization for miR detection in the paired resected human PDAC tissues showed that miR-125b-5p and miR-99a-5p are highly expressed in inflammatory cells in the tumor stroma, located in clusters of CD79A expressing cells of the B-lymphocyte lineage. In conclusion, we found that circulating miR-125b-5p and miR-99a-5p are potential immune-cell related prognostic biomarkers in PDAC patients after surgery.

The Role of MicroRNA in Paediatric Acute Lymphoblastic Leukaemia: Challenges for Diagnosis and Therapy

Acute lymphoblastic leukaemia (ALL) is the most common cancer of childhood. Although the overall survival of children with ALL is now more than 90%, leukaemia remains one of the leading causes of death from disease. In developed countries, the overall survival of patients with ALL has increased to more than 80%; however, those children cured from ALL still show a significant risk of short- and long-term complications as a consequence of their treatment. Accordingly, there is a need not only to develop new methods of diagnosis and prognosis but also to provide patients with less toxic therapies. MicroRNAs (miRNAs) are small ribonucleic acids (RNA), usually without coding potential, that regulate gene expression by directing their target messenger RNAs (mRNAs) for degradation or translational suppression. In paediatric ALL, several miRNAs have been observed to be overexpressed or underexpressed in patient cohorts compared to healthy individuals, while numerous studies have identified specific miRNAs that can be used as biomarkers to diagnose ALL, classify it into subgroups, and predict prognosis. Likewise, a variety of miRNAs identify as candidate targets for treatment, although there are numerous obstacles to overcome before their clinical use in patients. Here, we summarise the roles played by different miRNAs in childhood leukaemia, focussing primarily on their use as diagnostic tools and potential therapeutic targets, as well as a role in predicting treatment outcome. Finally, we discuss the potential roles of miRNA in immunotherapy and the novel contributions made by gut miRNAs to regulation of the host microbiome.

MiR-125b-5p and miR-181b-5p inhibit keratinocyte proliferation in skin by targeting Akt3

MicroRNAs (miRNAs) have been widely accepted to play important roles in the regulation of keratinocyte functions. Here, we aimed to further explore the role and underlying mechanism of miR-125b-5p and miR-181b-5p in psoriasis. The expression levels of miR-125b-5p, miR-181b-5p and Akt3 mRNA were detected by qRT-PCR assay. Cell proliferation ability was determined by MTT assay and BrdU incorporation assay. Dual-luciferase reporter assay and RNA Immunoprecipitation assay were used to confirm the targeted interaction between miR-125b-5p or miR-181b-5p and Akt3 in human epidermal keratinocytes (HEKs). The levels of ki-67, Akt3 protein, Akt, p-Akt, mTOR and p-mTOR were measured by Western blot. Our study indicated that miR-125b-5p and miR-181b-5p were downregulated (about 61.3% with miR-125b-5p and 60.4% with miR-181b-5p) and Akt3 was upregulated (about 2.68-fold) in psoriasis. Upregulation of miR-125b-5p or miR-181b-5p resulted in about a 33% or 40% reduction of HEKs proliferation in vitro, while Akt3 overexpression triggered a 1.3-fold enhancement on HEKs proliferation. Akt3 was a direct target of miR-125b-5p or miR-181b-5p. Moreover, HEKs proliferation ability in cotransfection of miR-125b-5p mimics (or miR-181-5p mimics) and vector-Akt3 group was about 2-fold (or 1.98-fold) that in the miR-125b-5p mimics (or miR-181-5p mimics) alone group. Akt/mTOR signaling was involved in miR-125b-5p mimics- or miR-181b-5p mimics-mediated inhibition effect on HEKs proliferation. Our study suggested that the upregulation of miR-125b-5p or miR-181b-5p inhibited HEKs proliferation at least partly by targeting Akt3, providing novel mechanisms of miRNAs involved in psoriasis.

MicroRNAs and their involvement in T-ALL: A brief overview

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy in which the transformed clone is arrested during T-cell development. Several genetic and epigenetic events have been implicated in this transformation. MicroRNAs (miRNAs) are small, non-coding RNAs that primarily function as endogenous translational repressors of protein-coding genes. The involvement of miRNAs in the regulation of cancer progression is well-established, namely by down-regulating the expression of key oncogenes or tumor suppressors and thereby preventing or promoting tumorigenesis, respectively. Similar to other cancers, several miRNA genes have been identified and implicated in the context of T-ALL. In this review we focused on the most studied microRNAs associated with T-ALL pathogenesis.

Genome-wide miRNA profiling and pivotal roles of miRs 125a-5p and 17-92 cluster in human neutrophil maturation and differentiation of acute myeloid leukemia cells

MicroRNAs (miRNAs, miRs) are short non-coding post-transcriptional regulators of gene expression in normal physiology and disease. Acute myeloid leukemia is characterized by accumulation of malignantly transformed immature myeloid precursors, and differentiation therapy, used to overcome this differentiation blockage, has become a successful therapeutic option. The human HL-60 acute leukemia cell line serves as a cell culture model for granulocytic maturation, and dimethyl sulfoxide (DMSO) incubation leads to its differentiation towards neutrophil-like cells, as assessed by biochemical, functional and morphological parameters. DMSO-induced HL-60 cell differentiation constitutes an excellent model to examine molecular processes that turn a proliferating immortal leukemic cell line into mature non-proliferating and apoptosis-prone neutrophil-like end cells. By performing genome-wide miRNA profiling and functional assays, we have identified a signature of 86 differentially expressed canonical miRNAs (51 upregulated; 35 downregulated) during DMSO-induced granulocytic differentiation of HL-60 cells. Quantitative real-time PCR was used to validate miRNA expression. Among these differentially expressed canonical miRNAs, we found miR-125a-5p upregulation and miR-17-92 cluster downregulation acted as major regulators of granulocytic differentiation in HL-60 cells. Enforced expression of miR-125a-5p promoted granulocytic differentiation in HL-60 cells, whereas miR-17-92 ectopic expression inhibited DMSO-induced HL-60 granulocytic differentiation. Ectopic expression of miR-125a-5p also promoted granulocytic differentiation in human acute promyelocytic leukemia NB4 cells, as well as in naïve human primary CD34⁺-hematopoietic progenitor/stem cells. These findings provide novel molecular insights into the identification of miRNAs regulating granulocytic differentiation of human leukemia cells and normal CD34⁺-hematopoietic progenitor/stem cells, and may assist in the development of novel miRNA-targeted therapies for leukemia.