miR-122 regulates p53/Akt signalling and the chemotherapy-induced apoptosis in cutaneous T-cell lymphoma

Exosomal microRNAs as biomarkers for viral replication in tofacitinib-treated rheumatoid arthritis patients with hepatitis C

Notwithstanding recent advances in direct antiviral specialists (DAAs) for hepatitis C infection (HCV), it is yet a pervasive overall issue in patients with rheumatoid arthritis (RA). Exosomal microRNAs (miRNAs) is associated with HCV infection. However, it remains unknown how miRNAs respond following biologic disease-modifying antirheumatic drug (bDMARD) and targeted synthetic DMARD (tsDMARD) treatment in HCV patients with RA. We prospectively recruited RA patients taking anti-tumor necrosis factor-α (TNF-α) inhibitors rituximab (RTX) and tofacitinib. The serum hepatitis C viral load was measured using real-time quantitative reverse transcriptase PCR before and 6 months after bDMARD and tsDMARD therapy. HCV RNA replication activity was measured using an HCV-tricistronic replicon reporter system, and quantitative analysis of hsa-mir-122-5p and hsa-mir-155-5p in patients was performed using quantitative PCR. HCV RNA replication in hepatocytes was not affected by tofacitinib or TNF-α inhibitor treatment. Hsa-mir-155-5p and hsa-mir-122-5p were significantly expanded in RA patients with HCV as compared with those without HCV. We observed a dramatic increase in hsa-mir-122-5p and a decrease in hsa-mir-155-5p expression levels in patients taking RTX in comparison with other treatments. Finally, a reduction in hsa-mir-122-5p and an increase in hsa-mir-155-5p were observed in a time-dependent manner after tofacitinib and DAA therapy in RA-HCV patients. These results showed that hsa-mir-155-5p and hsa-mir-122-5p were significantly increased in RA-HCV patients as compared with those without HCV after taking tofacitinib. Hsa-mir-155-5p and hsa-mir-122-5p may be potential biomarkers for treatment efficacy in RA patients with HCV.

Therapeutic challenges in peripheral T-cell lymphoma

Peripheral T-cell lymphoma (PTCL) is a rare and heterogeneous group of hematological malignancies. Compared to our knowledge of B-cell tumors, our understanding of T-cell leukemia and lymphoma remains less advanced, and a significant number of patients are diagnosed with advanced stages of the disease. Unfortunately, the development of drug resistance in tumors leads to relapsed or refractory peripheral T-Cell Lymphomas (r/r PTCL), resulting in highly unsatisfactory treatment outcomes for these patients. This review provides an overview of potential mechanisms contributing to PTCL treatment resistance, encompassing aspects such as tumor heterogeneity, tumor microenvironment, and abnormal signaling pathways in PTCL development. The existing drugs aimed at overcoming PTCL resistance and their potential resistance mechanisms are also discussed. Furthermore, a summary of ongoing clinical trials related to PTCL is presented, with the aim of aiding clinicians in making informed treatment decisions.

The role and mechanism of action of microRNA-122 in cancer: Focusing on the liver

microRNA-122 (miR-122) is a highly conserved microRNA that is predominantly expressed in the liver and plays a critical role in the regulation of liver metabolism. Recent studies have shown that miR-122 is involved in the pathogenesis of various types of cancer, particularly liver cancer. In this sense, The current findings highlighted the potential role of miR-122 in regulating many vital processes in cancer pathophysiology, including apoptosis, signaling pathway, cell metabolism, immune system response, migration, and invasion. These results imply that miR-122, which has been extensively studied for its biological functions and potential therapeutic applications, acts as a tumor suppressor or oncogene in cancer development. We first provide an overview and summary of the physiological function and mode of action of miR-122 in liver cancer. We will examine the various signaling pathways and molecular mechanisms through which miR-122 exerts its effects on cancer cells, including the regulation of oncogenic and tumor suppressor genes, the modulation of cell proliferation and apoptosis, and the regulation of metastasis. Most importantly, we will also discuss the potential diagnostic and therapeutic applications of miR-122 in cancer, including the development of miRNA-based biomarkers for cancer diagnosis and prognosis, and the potential use of miR-122 as a therapeutic target for cancer treatment.

Role of cytokine in malignant T-cell metabolism and subsequent alternation in T-cell tumor microenvironment

T cells are an important component of adaptive immunity and T-cell-derived lymphomas are very complex due to many functional sub-types and functional elasticity of T-cells. As with other tumors, tissues specific factors are crucial in the development of T-cell lymphomas. In addition to neoplastic cells, T- cell lymphomas consist of a tumor micro-environment composed of normal cells and stroma. Numerous studies established the qualitative and quantitative differences between the tumor microenvironment and normal cell surroundings. Interaction between the various component of the tumor microenvironment is crucial since tumor cells can change the microenvironment and vice versa. In normal T-cell development, T-cells must respond to various stimulants deferentially and during these courses of adaptation. T-cells undergo various metabolic alterations. From the stage of quiescence to attention of fully active form T-cells undergoes various stage in terms of metabolic activity. Predominantly quiescent T-cells have ATP-generating metabolism while during the proliferative stage, their metabolism tilted towards the growth-promoting pathways. In addition to this, a functionally different subset of T-cells requires to activate the different metabolic pathways, and consequently, this regulation of the metabolic pathway control activation and function of T-cells. So, it is obvious that dynamic, and well-regulated metabolic pathways are important for the normal functioning of T-cells and their interaction with the microenvironment. There are various cell signaling mechanisms of metabolism are involved in this regulation and more and more studies have suggested the involvement of additional signaling in the development of the overall metabolic phenotype of T cells. These important signaling mediators include cytokines and hormones. The impact and role of these mediators especially the cytokines on the interplay between T-cell metabolism and the interaction of T-cells with their micro-environments in the context of T-cells lymphomas are discussed in this review article.

Lnc-HULC, miR-122, and sirtulin-1 as potential diagnostic biomarkers for psoriasis and their association with the development of metabolic syndrome during the disease course

Psoriasis is a persistent inflammatory skin disorder driven by T cells. The disease is characterized by aberrant keratinocytes (KCs) differentiation, epidermal proliferation, and excessive hyperplasia of veins and arteries. The purpose of the study was to identify the levels of circulating lnc-HULC, miR-122, and Sirtuin 1 (SIRT-1) in psoriatic patients, evaluate their possible roles as diagnostic biomarkers, and link their levels with the development of metabolic syndrome during psoriasis progression. This study included 176 participants. The subjects were divided into four groups, with 44 participants in each group. All patients have undergone a complete history taking and clinical examination. Laboratory investigations included Low-density lipoprotein (LDL), High-density lipoprotein (HDL), Triglycerides (TG), Fasting blood sugar (FBS), and cholesterol plasma levels. Serum levels of miR-122 and lnc-HULC were examined by qRT-PCR. Serum levels of SIRT-1 were examined by ELISA. The serum concentrations of lnc-HULC and miR-122 were significantly higher in psoriatic participants compared to controls. Psoriatic patients' serum concentrations of SIRT-1 were much lower than those of healthy individuals. There was a negative association between SIRT-1 concentration and BMI, disease duration, PASI score, LDL, and cholesterol levels. The blood levels of lnc-HULC, miR-122, and SIRT-1 in psoriasis patients provide a promising role as diagnostic biomarkers in patients with and without metabolic syndrome.

Interruption of p53-MDM2 Interaction by Nutlin-3a in Human Lymphoma Cell Models Initiates a Cell-Dependent Global Effect on Transcriptome and Proteome Level

In most lymphomas, p53 signaling pathway is inactivated by various mechanisms independent to p53 gene mutations or deletions. In many cases, p53 function is largely regulated by alterations in the protein abundance levels by the action of E3 ubiquitin-protein ligase MDM2, targeting p53 to proteasome-mediated degradation. In the present study, an integrating transcriptomics and proteomics analysis was employed to investigate the effect of p53 activation by a small-molecule MDM2-antagonist, nutlin-3a, on three lymphoma cell models following p53 activation. Our analysis revealed a system-wide nutlin-3a-associated effect in all examined lymphoma types, identifying in total of 4037 differentially affected proteins involved in a plethora of pathways, with significant heterogeneity among lymphomas. Our findings include known p53-targets and novel p53 activation effects, involving transcription, translation, or degradation of protein components of pathways, such as a decrease in key members of PI3K/mTOR pathway, heat-shock response, and glycolysis, and an increase in key members of oxidative phoshosphorylation, autophagy and mitochondrial translation. Combined inhibition of HSP90 or PI3K/mTOR pathway with nutlin-3a-mediated p53-activation enhanced the apoptotic effects suggesting a promising strategy against human lymphomas. Integrated omic profiling after p53 activation offered novel insights on the regulatory role specific proteins and pathways may have in lymphomagenesis.

Biomarkers for Assessment of Human Immunodeficiency Virus and its Co-Infection with Hepatitis B and Hepatitis C Viruses: A Comprehensive Review

Recently, prevalence of hepatitis B virus (HBV), and hepatitis C virus (HCV) co-infection with Human immunodeficiency virus (HIV), has dramatically increased worldwide due to their shared routes of transmission. Compared to the sporadic infection with HIV, HBV, and HCV, concurrent infection with these agents increases the complications of these viruses. Furthermore, co-infection may also alter the therapeutic strategies against HIV. Accordingly, choosing appropriate biomarkers to detect these co-infections is one of the main concerns in the field of diagnostic pathology. Up to now, several markers have been introduced for the simultaneous diagnosis of HIV, HBV, and HCV. In this regard, serum adenosine deaminase activity (ADA), FibroTests, AST-to-Platelet Ratio Index (APRI), Fibrosis-4, Hyaluronic acid, and micro ribonucleic acids (MiR) have been investigated as potential biomarkers for diagnosis of HIV-HCV/HBV co-infections. This review summarizes diagnostic values of the current and emerging biomarkers in HIV patients concurrently infected with HBV and HCV.

Expression analysis of circulating miR-22, miR-122, miR-217 and miR-367 as promising biomarkers of acute lymphoblastic leukemia

BACKGROUND

The role of serum-based biomarkers such as microRNAs in cancer diagnosis has been extensively established. This study aimed to determine the expression levels of bioinformatically selected miRNAs and whether they can be used as biomarkers or a new therapeutic target in patients with acute lymphoblastic leukemia (ALL).

MATERIALS AND METHODS

The expression levels of serum miR-22, miR-122, miR-217, and miR-367 in 21 ALL patients and 21 healthy controls were measured using quantitative real-time PCR. The receiver operating characteristic (ROC) curve and the associated area under the curve (AUC) was used to assess candidate miRNAs' diagnostic value as a biomarker.

RESULTS

The results showed that miR-217 was markedly decreased in patients with ALL compared to controls. Moreover, miR-22, miR-122, and miR-367 were found to be upregulated. Furthermore, ROC analysis showed that serum miR-217 and miR-367 could differentiate ALL patients from healthy individuals, while miR-22 has approximate discriminatory power that requires further investigation.

CONCLUSION

These results provide promising preliminary evidence that circulating miR-217 and miR-367 could be considered potent diagnostic biomarkers and therapeutic goals in this disease.

Molecular pathogenesis of Cutaneous T cell Lymphoma: Role of chemokines, cytokines, and dysregulated signaling pathways

Cutaneous T cell lymphomas (CTCLs) are a heterogeneous group of lymphoproliferative neoplasms that exhibit a wide spectrum of immune-phenotypical, clinical, and histopathological features. The biology of CTCL is complex and remains elusive. In recent years, the application of next-generation sequencing (NGS) has evolved our understanding of the pathogenetic mechanisms, including genetic aberrations and epigenetic abnormalities that shape the mutational landscape of CTCL and represent one of the important pro-tumorigenic principles in CTCL initiation and progression. Still, identification of the major pathophysiological pathways including genetic and epigenetic components that mediate malignant clonal T cell expansion has not been achieved. This is of prime importance given the role of malignant T cell clones in fostering T helper 2 (Th2)-bias tumor microenvironment and fueling progressive immune dysregulation and tumor cell growth in CTCL patients, manifested by the secretion of Th2-associated cytokines and chemokines. Alterations in malignant cytokine and chemokine expression patterns orchestrate the inflammatory milieu and influence the migration dynamics of malignant clonal T cells. Here, we highlight recent insights about the molecular mechanisms of CTCL pathogenesis, emphasizing the role of cytokines, chemokines, and associated downstream signaling networks in driving immune defects, malignant transformation, and disease progression. In-depth characterization of the CTCL immunophenotype and tumoral microenvironment offers a facile opportunity to expand the therapeutic armamentarium of CTCL, an intractable malignant skin disease with poor prognosis and in dire need of curative treatment approaches.

MicroRNAs and their signaling pathway in mycosis fungoides

BACKGROUND

Oncogenic microRNAs, a kind of stable epigenetic inhibitors, often deregulated in Mycosis fungoides (MF) which affect the skin and tend to transform and spread.

RESULTS

Previous studies investigating the de-expression of microRNA in MF patients skin biopsies identified that they were not only regulated by signaling pathway, but also regulated other signaling pathway. Furthermore, studies have elucidated the molecular mechanisms of the STAT signaling pathway that can promote a great diversity of miRNA expression via cytokine binding receptors, activating Janus kinase-3 and STAT proteins. But some non-STAT signaling pathway with mircoRNA de-expression in MF was incomplete.

CONCLUSION

Taken together, these studies demonstrate that microRNA may be used as the prognosis, progression and diagnose of MF, as they can not only control MF cell proliferation, but also induce MF cell apoptosis.

The Role of microRNA in Pathogenesis, Diagnosis, Different Variants, Treatment and Prognosis of Mycosis Fungoides

Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma (CTCL), accounting for approximately 50% of all CTCLs. Although various molecular changes in MF have been described in existing studies, no obvious disease-specific changes have been found thus far. microRNAs (miRs) are short, noncoding RNA molecules that play roles in the post-transcriptional regulation of oncogenes and tumor suppressor genes in various diseases. Recently, there has been rapidly expanding experimental evidence for the role of miRs in the progression, early diagnosis, prognosis prediction for MF. Efforts to improve early diagnosis and develop personalized therapy options have become more important in recent years. Here, we provide an overview and update of recent advances regarding miRs associated with MF. Furthermore, we provide insights into future opportunities for miR-based therapies.

Inhibition of extracellular vesicle-associated MMP2 abrogates intercellular hepatic miR-122 transfer to liver macrophages and curtails inflammation

Hepatic miRNA, miR-122, plays an important role in controlling metabolic homeostasis in mammalian liver. Intercellular transfer of miR-122 was found to play a role in controlling tissue inflammation. miR-122, as part of extracellular vesicles released by lipid-exposed hepatic cells, are taken up by tissue macrophages to activate them and produce inflammatory cytokines. Matrix metalloprotease 2 or MMP2 was found to be essential for transfer of extracellular vesicles and their miRNA content from hepatic to non-hepatic cells. MMP2 was found to increase the movement of the extracellular vesicles along the extracellular matrix to enhance their uptake in recipient cells. Inhibition of MMP2 restricts functional transfer of hepatic miRNAs across the hepatic and non-hepatic cell boundaries, and by targeting MMP2, we could reduce the innate immune response in mammalian liver by preventing intra-tissue miR-122 transfer. MMP2 thus could be a useful target to restrict high-fat-diet-induced obesity-related metaflammation.

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Hepatocytes on exposure to high lipid export proinflammatory miR-122 in mouse liver

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Uptake of extracellular miR-122 induces inflammatory signals in liver macrophages

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MMP2 on extracellular vesicles is essential for intercellular transfer of miRNA

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Inhibition of MMP2 prevents miR-122 transfer and stops activation of macrophages

Schisandrin B Attenuates Colitis-Associated Colorectal Cancer through SIRT1 Linked SMURF2 Signaling

Colon cancer, a common type of malignant tumor, seriously endangers human health. However, due to the relatively slow progress in diagnosis and treatment, the clinical therapeutic technology of colon cancer has not been substantially improved in the past three decades. The present study was designed to investigate the effects and involved mechanisms of schisandrin B in cell growth and metastasis of colon cancer. C57BL/6 mice received AOM and dextran sulfate sodium. Mice in treatment groups were gavaged with 3.75-30 mg/kg/day of schisandrin B. Transwell chamber migration, enzyme-linked immunosorbent assay (ELISA), Western blot analysis, immunoprecipitation (IP) and immunofluorescence were conducted, and HCT116 cell line was employed in this study. Data showed that schisandrin B inhibited tumor number and tumor size in the AOD+DSS-induced colon cancer mouse model. Schisandrin B also inhibited cell proliferation and metastasis of colon cancer cells. We observed that schisandrin B induced SMURF2 protein expression and affected SIRT1 in vitro and in vivo. SMURF2 interacted with SIRT1 protein, and there was a negative correlation between SIRT1 and SMURF2 expressions in human colorectal cancer. The regulation of SMURF2 was involved in the anticancer effects of schisandrin B in both in vitro and in vivo models. In conclusion, the present study revealed that schisandrin B suppressed SIRT1 protein expression, and SIRT1 is negatively correlated with the induction of SMURF2, which inhibited cell growth and metastasis of colon cancer. Schisandrin B could be a leading compound, which will contribute to finding novel potential agents and therapeutic targets for colon cancer.

Potential roles for microRNAs in facilitating physiological adaptation to low-temperature stress in Penaeus vannamei

Water temperature is one of the most common physiological stressors in aquaculture. Previous studies demonstrate that organisms require miRNA activity for survival in various unfavourable environmental conditions. However, the detailed role of miRNA in response to low-temperature stress is still unclear. This study was conducted to construct a comprehensive miRNA dataset for the Penaeus vannamei after low-temperature stress. A total of 329 known miRNAs and 60 putative novel miRNAs were identified. Among them, 17 miRNAs were identified with the most significant differences, and they were found to be involved in stimulation or stress processes. The main enriched target pathways of the 17 miRNAs were the Hippo signalling pathway, autophagy, apoptosis and MAPK signalling. In addition, all the 17 miRNAs identified were up-regulated, suggesting that miRNA by inhibiting the expression of target genes constitutes an effective strategy for Penaeus vannamei to cope with low-temperature stress. The 35-putative target of the 17 miRNAs was related to apoptosis and autophagy-related proteins, such as Pxt, DRAM2, cytochrome c, ATG2B, JNK, ATG4 and API5. The analysis of miRNA expression profiles contributes to the understanding of the molecular mechanisms of low-temperature tolerance in Penaeus vannamei. This study's findings enrich current miRNA resources and offer the possibility to validate the involvement of 17 miRNAs in the response of shrimp to low-temperature stress.

MicroRNA‑10b modulates cisplatin tolerance by targeting p53 directly in lung cancer cells

MicroRNA (miRNA or miR)‑10b is an oncogenic miRNA associated with metastasis that is present in various types of tumor, including lung cancer. However, whether miR‑10b is involved in different malignant characteristics, such as drug resistance or stemness, remains unclear. Therefore, the present study investigated whether miR‑10b is an upstream regulator of p53. Ectopic expression of miR‑10b‑agomir decreased the expression of p53 and its downstream effectors, such as Bax and p53 upregulated modulator of apoptosis. Two non‑canonical sites, including 1,580‑1,587 and 2,029‑2,035, located in p53 3'‑untranslated region (UTR) were affected by the presence of miR‑10b. In functional assays, upregulation of the p53 signaling pathway following cisplatin treatment was associated with decreased levels of miR‑10b and upregulation of the luciferase activity of wild‑type, but not 1,584, 2,032‑dual‑mutant, p53 3'‑UTR. The ectopic expression of miR‑10b‑agomir attenuated the stability of p53 3'‑UTR and the expression of p53 and its downstream effectors induced by cisplatin. By contrast, the knockdown of miR‑10b induced the stability of p53 3'‑UTR and increased levels of p53 and the sensitivity of A549 cells to cisplatin treatment. Similar results were also observed for Beas 2B cells. In the clinical investigation, p53 exhibited two distinct associations (cocurrent and countercurrent) with miR‑10b in patients with lung cancer. Patients with lung cancer with low p53 and high miR‑10b levels exhibited the poorest prognosis, while those with high p53 and low miR‑10b exhibited the most favorable prognosis. These findings indicate a novel pathway in which cisplatin induces the levels of p53 by increasing mRNA stability via miR‑10b, indicating a novel oncogenic role of miR‑10b in promoting the malignant characteristics of non‑small cell lung carcinoma.

Circulating microRNA-122, microRNA-126-3p and microRNA-146a are associated with inflammation in patients with pre-diabetes and type 2 diabetes mellitus: A case control study

The prevalence of type 2 diabetes mellitus (T2DM) is increasing dramatically worldwide. Dysregulation of microRNA (miRNA) as key regulators of gene expression, has been reported in numerous diseases including diabetes. The aim of this study was to investigate the expression levels of miRNA-122, miRNA-126-3p and miRNA-146a in diabetic and pre-diabetic patients and in healthy individuals, and to determine whether the changes in the level of these miRNAs are reliable biomarkers in diagnosis, prognosis, and pathogenesis of T2DM. Additionally, we examined the relationship between miRNA levels and plasma concentrations of inflammatory factors including tumor necrosis factor alpha (TNF-α) and interleukin 6 (Il-6) as well as insulin resistance. In this case-control study, participants (n = 90) were allocated to three groups (n = 30/group): T2DM, pre-diabetes and healthy individuals as control (males and females, age: 25–65, body mass index: 25–35). Expression of miRNA was determined by real-time polymerase chain reaction (RT-PCR). Furthermore, plasma concentrations of TNF-α, IL-6 and fasting insulin were measured by enzyme-linked immunosorbent assay. Homeostatic model assessment for insulin resistance (HOMA-IR) was calculated as an indicator of insulin resistance. MiRNA-122 levels were higher while miRNA-126-3p and miRNA-146a levels were lower in T2DM and pre-diabetic patients compared to control (p<0.05). Furthermore, a positive correlation was found between miRNA-122 expression and TNF-α (r = 0.82), IL-6 (r = 0.83) and insulin resistance (r = 0.8). Conversely, negative correlations were observed between miRNA-126-3p and miRNA-146a levels and TNF-α (r = -0.7 and r = -0.82 respectively), IL-6 (r = -0.65 and r = -0.78 respectively) as well as insulin resistance (r = -0.67 and r = -0.78 respectively) (all p<0.05). Findings of this study suggest the miRNAs can potentially contribute to the pathogenesis of T2DM. Further studies are required to examine the reproducibility of these findings.

Cell signaling in cutaneous T-cell lymphoma microenvironment: promising targets for molecular-specific treatment

Cutaneous T-cell lymphomas (CTCL) result from the infiltration and proliferation of a population of T cells in the skin, inducing changes in the activity of both T cells and surrounding skin cells. In the CTCL microenvironment, cell interactions mediated by cell signaling pathways are altered. Defining changes in cell signaling enables to understand T-cell deregulations in the CTCL microenvironment and thus the progression of the disease. Moreover, characterizing signaling networks activated in CTCL stages can lead to consider new molecular biomarkers and therapeutic targets. Focusing on mycosis fungoides (MF), the most frequent variant of CTCL, and Sézary syndrome (SS), its leukemic variant, this review highlights recent molecular and genetic findings revealing modifications of key signaling pathways involved in (1) cell proliferation, cell growth, and cell survival such as MAP kinases and PI3K/Akt; (2) immune responses derived from TCR, TLR, JAK/STAT, and NF-kB; and (3) changes in tissue conditions such as extracellular matrix remodeling, hypoxia, and angiogenesis. Alterations in these signaling networks promote malignant T-cell proliferation and survival, T-cell migration, inflammation, and suppression of immune regulation of malignant T cells, making a skin microenvironment that allows disease progression. Targeting key proteins of these signaling pathways, using molecules already available and used in research, in clinical trials, and with other disease indications, can open the way to different therapeutic options in CTCL treatment.

The Roles of Epinephelus coioides miR-122 in SGIV Infection and Replication

In mammals, mature miR-122 is 22 nucleotides long and can be involved in regulating a variety of physiological and biological pathways. In this study, the expression profile and effects of grouper Epinephelus coioides miR-122 response to Singapore grouper iridovirus (SGIV) infection were investigated. The sequences of mature microRNAs (miRNAs) from different organisms are highly conserved, and miR-122 from E. coioides exhibits high similarity to that from mammals and other fish. The expression of miR-122 was up-regulated during SGIV infection. Up-regulation of miR-122 could significantly enhance the cytopathic effects (CPE) induced by SGIV, the transcription levels of viral genes (MCP, VP19, LITAF and ICP18), and viral replication; reduce the expression of inflammatory factors (TNF-a, IL-6, and IL-8), and the activity of AP-1 and NF-κB, and miR-122 can bind the target gene p38α MAPK to regulate the SGIV-induced cell apoptosis and the protease activity of caspase-3. The results indicated that SGIV infection can up-regulate the expression of E. coioides miR-122, and up-regulation of miR-122 can affect the activation of inflammatory factors, the activity of AP-1 and NF-κB, and cell apoptosis to regulate viral replication and proliferation.

miRNAs mediated drug resistance in hematological malignancies

Despite improvements in the therapeutic approaches for hematological malignancies in the last decades, refractory disease still occurs, and cancer drug resistance still remains a major hurdle in the clinical management of these cancer patients. The investigation of this problem has been extensive and different mechanism and molecules have been associated with drug resistance. MicroRNAs (miRNAs) have been described as having an important action in the emergence of cancer, including hematological tumors, and as being major players in their progression, aggressiveness and response to treatments. Moreover, miRNAs have been strongly associated with cancer drug resistance and with the modulation of the sensitivity of cancer cells to a wide array of anticancer drugs. Furthermore, this role has also been reported for miRNAs packaged into extracellular vesicles (EVs-miRNAs), which in turn have been described as essential for the horizontal transfer of drug resistance to sensitive cells. Several studies have been suggesting the use of miRNAs as biomarkers for drug response and clinical outcome prediction, as well as promising therapeutic tools in hematological diseases. Indeed, the combination of miRNA-based therapeutic tools with conventional drugs contributes to overcome drug resistance. This review addresses the role of miRNAs in the pathogenesis of hematological malignances, namely multiple myeloma, leukemias and lymphomas, highlighting their important action (either in their cell-free circulating form or within circulating EVs) in drug resistance and their potential clinical applications.

Epigenetics of cutaneous T-cell lymphoma: biomarkers and therapeutic potentials

Cutaneous T-cell lymphomas (CTCLs) are a heterogeneous group of skin-homing non-Hodgkin lymphomas. There are limited options for effective treatment of patients with advanced-stage CTCL, leading to a poor survival rate. Epigenetics plays a pivotal role in regulating gene expression without altering the DNA sequence. Epigenetic alterations are involved in virtually all key cancer-associated pathways and are fundamental to the genesis of cancer. In recent years, the epigenetic hallmarks of CTCL have been gradually elucidated and their potential values in the diagnosis, prognosis, and therapeutic intervention have been clarified. In this review, we summarize the current knowledge of the best-studied epigenetic modifications in CTCL, including DNA methylation, histone modifications, microRNAs, and chromatin remodelers. These epigenetic regulators are essential in the development of CTCL and provide new insights into the clinical treatments of this refractory disease.

MiR-122 is involved in immune response by regulating Interleukin-15 in the orange-spotted grouper (Epinephelus coioides)

Epinephelus coioides is an important economic culture marine fish and is susceptible to various pathogenic diseases. Increasingly evidences showed that miRNAs participated in the regulation of the cell proliferation, differentiation and immune response. MiR-122 has been reported to play an essential role in immune response by triggering an inflammatory reaction. However, the function of miR-122 in response to bacterial infection is unclear in Epinephelus coioides. Herein, we report that miR-122 is involved in response to Aeromonas hydrophila infection of grouper spleen cells (GS). IL-15, IL-6 and IL-1β are inhibited in overexpression miR-122 GS cells, while induced in silence miR-122 GS cells. In addition, IL-15 is predicted to be the target gene of miR-122, which is further confirmed by LUC. Taken together, we propose that miR-122 regulates the immune response to bacterial infection by triggering IL-15.

Overexpression of MicroRNA-122 Resists Oxidative Stress-Induced Human Umbilical Vascular Endothelial Cell Injury by Inhibition of p53

Deep venous thrombosis (DVT) constitutes a great threat to health worldwide. Endothelial cell injury and dysfunction comprise the critical contributor for the development of DVT. However, the mechanism behind it remains poorly elucidated. The study is aimed at investigating the role of microRNA-122 (miR-122) and oxidative stress on DVT. The results showed that miR-122 overexpression dampened H₂O₂-evoked cytotoxic injury in human umbilical vein endothelial cells (HUVECs) by increasing cell viability, suppressing cell apoptosis and oxidative stress injury. Notably, miR-122 overexpression attenuated provasoconstriction factor endothelin-1 (ET-1) expression in HUVECs exposed to H₂O₂ but enhanced the productions of vasodilatation factor Prostaglandin F1α (PGF1α). Moreover, inhibition of miR-122 had the opposite results. miR-122 could inhibit the expression of p53. Low expression of p53 could enhance the protection of miR-122 on HUVEC injury. This study highlights that miR-122 overexpression may restore H₂O₂-induced HUVEC injury by regulating the expression of p53.

Microbiota Imbalance Contributes to COPD Deterioration by Enhancing IL-17a Production via miR-122 and miR-30a

The changes of microbiota in lungs could change interleukin-17a (IL-17a) expression by altering microRNAs (miRNAs) profile, thus contributing to the pathogenesis of chronic obstructive pulmonary disease (COPD). In this study, we aimed to study molecular mechanisms’ underlying effect of microbiota imbalance on COPD deterioration. Real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) were performed to analyze expression of miRNAs and IL-17a mRNA. ELISA was used to evaluate abundance of IL-17a in plasma, peripheral blood monocyte, and sputum of COPD mice and patients. Luciferase assay was performed to explore underlying molecular mechanisms. The expression of miR-122, miR-30a, and miR-99b were remarkably decreased in COPD mice, while the expression of IL-17a was notably increased in plasma, peripheral blood monocytes, and lung tissues of COPD mice. The levels of Lactobacillus/Moraxella and IL-17a expression were significantly enhanced in sputum of exacerbated COPD patients, along with notably decreased expression of miR-122 and miR-30a. Luciferase assay confirmed that miR-122 and miR-30a played an inhibitory role in IL-17a expression. We identified miR-122 and miR-30a as differentially expressed miRNAs in sputum and plasma of COPD patients in exacerbation-month12 group. Furthermore, downregulated miR-122 and miR-30a expression associated with microbiota imbalance may contribute to COPD deterioration by enhancing IL-17a production.

MicroRNAs in the Pathogenesis, Diagnosis, Prognosis and Targeted Treatment of Cutaneous T-Cell Lymphomas

Cutaneous T-cell lymphoma (CTCL) represents a heterogeneous group of potentially devastating primary skin malignancies. Despite decades of intense research efforts, the pathogenesis is still not fully understood. In the early stages, both clinical and histopathological diagnosis is often difficult due to the ability of CTCL to masquerade as benign skin inflammatory dermatoses. Due to a lack of reliable biomarkers, it is also difficult to predict which patients will respond to therapy or progress towards severe recalcitrant disease. In this review, we discuss recent discoveries concerning dysregulated microRNA (miR) expression and putative pathological roles of oncogenic and tumor suppressive miRs in CTCL. We also focus on the interplay between miRs, histone deacetylase inhibitors, and oncogenic signaling pathways in malignant T cells as well as the impact of miRs in shaping the inflammatory tumor microenvironment. We highlight the potential use of miRs as diagnostic and prognostic markers, as well as their potential as therapeutic targets. Finally, we propose that the combined use of miR-modulating compounds with epigenetic drugs may provide a novel avenue for boosting the clinical efficacy of existing anti-cancer therapies in CTCL.

MiRNAs as Novel Adipokines: Obesity-Related Circulating MiRNAs Influence Chemosensitivity in Cancer Patients

Adipose tissue is an endocrine organ, capable of regulating distant physiological processes in other tissues via the release of adipokines into the bloodstream. Recently, circulating adipose-derived microRNAs (miRNAs) have been proposed as a novel class of adipokine, due to their capacity to regulate gene expression in tissues other than fat. Circulating levels of adipokines are known to be altered in obese individuals compared with typical weight individuals and are linked to poorer health outcomes. For example, obese individuals are known to be more prone to the development of some cancers, and less likely to achieve event-free survival following chemotherapy. The purpose of this review was twofold; first to identify circulating miRNAs which are reproducibly altered in obesity, and secondly to identify mechanisms by which these obesity-linked miRNAs might influence the sensitivity of tumors to treatment. We identified 8 candidate circulating miRNAs with altered levels in obese individuals (6 increased, 2 decreased). A second literature review was then performed to investigate if these candidates might have a role in mediating resistance to cancer treatment. All of the circulating miRNAs identified were capable of mediating responses to cancer treatment at the cellular level, and so this review provides novel insights which can be used by future studies which aim to improve obese patient outcomes.

miRNA-Mediated Immune Regulation in Islet Autoimmunity and Type 1 Diabetes

The important role of microRNAs as major modulators of various physiological processes, including immune regulation and homeostasis, has been increasingly recognized. Consequently, aberrant miRNA expression contributes to the defective regulation of T cell development, differentiation, and function. This can result in immune activation and impaired tolerance mechanisms, which exert a cardinal function for the onset of islet autoimmunity and the progression to T1D. The specific impact of miRNAs for immune regulation and how miRNAs and their downstream targets are involved in the pathogenesis of islet autoimmunity and T1D has been investigated recently. These studies revealed that increased expression of individual miRNAs is involved in several layers of tolerance impairments, such as inefficient Treg induction and Treg instability. The targeted modulation of miRNAs using specific inhibitors, resulting in improved immune homeostasis, as well as improved methods for the targeting of miRNAs, suggest that miRNAs, especially in T cells, are a promising target for the reestablishment of immune tolerance.

Hongjingtian Injection Inhibits Proliferation and Migration and Promotes Apoptosis in High Glucose-Induced Vascular Smooth Muscle Cells

Background

Hongjingtian injection (HJT) is administered in the treatment of vascular diseases, including diabetic angiopathies (DA). However, its underlying mechanisms have not been examined systematically.

Methods

In this research, we explored potential mechanisms of HJT through network pharmacology. HG-stimulated A7r5 cells served as the cell model. Cell proliferation, migration and apoptosis were investigated. The effects on key targets and the AKT pathway were verified by Western blotting in experiments with the AKT inhibitor LY294002 or activator SC79.

Results

Network analysis predicted that HJT targeted 10 candidate targets and 15 pathways including cell proliferation, migration and apoptosis in response to DA. Functional experiments showed that HJT markedly suppressed the proliferation and migration and promoted the apoptosis of HG-induced VSMCs, which validated the prediction. Mechanistically, HJT significantly downregulated the expression of pAKT, MMP9, and PCNA, upregulated the expression of p53 and cleaved caspase-3 and increased the Bax/Bcl-2 ratio compared with the HG group. SC79, an AKT activator, partially reversed the inhibitory effects of HJT on HG-induced VSMCs, confirming the involvement of the AKT pathway. Furthermore, the presence of the AKT inhibitor LY294002 had a similar inhibitory effect as HJT.

Conclusion

These findings systematically evaluate the potential mechanisms of HJT for the treatment of DA. HJT suppressed the proliferation and migration and promoted the apoptosis of HG-induced VSMCs partly by inhibiting the AKT pathway. Additionally, this study may provide a quick and effective way to investigate the molecular mechanisms of traditional Chinese medicine.

MicroRNA-122 promotes endothelial cell apoptosis by targeting XIAP: Therapeutic implication for atherosclerosis

Endothelial cell (EC) apoptosis is fundamental for the pathophysiology of atherosclerosis, in which microRNAs (miRNAs) emerge as critical regulators. miR-122 has been shown to regulate the apoptosis of various cell types, however, whether miR-122 is associated with atherosclerosis and EC apoptosis remains unknown. In this study, we found that miR-122 expression was increased in the aortic ECs of ApoE^-/- mice fed with a high-fat diet (HFD), as compared to normal-diet (ND), implying a potential association between miR-122 elevation and atherogenesis. In addition, in vitro, miR-122 expression was also induced in human aortic ECs (HAECs) by the treatment of oxidized low-density lipoprotein (ox-LDL), a common atherogenic factor. Functionally, miR-122 knockdown suppressed ox-LDL-induced apoptosis of HAECs, suggesting a pro-apoptotic role of miR-122 in HAECs under this pro-atherogenic condition. Further evidence revealed that the X-linked inhibitor-of-apoptosis protein (XIAP) was directly targeted and suppressed by miR-122 in HAECs, and more importantly, XIAP knockdown diminished miR-122 effect on apoptosis, thus establishing XIAP as a prominent target that mediates miR-122 regulation of the apoptosis of HAECs. Together, these results may identify miR-122 as a novel regulator in EC apoptosis, which offers it as a possible target for therapeutic interventions of atherosclerosis.

Bortezomib inhibited the progression of diffuse large B-cell lymphoma via targeting miR-198

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma, which is an aggressive malignancy with high variance of clinical features and response to the treatment. The proteasome inhibitor bortezomib (BTZ) has been demonstrated to suppress the progression of DLBCL, however, the underlying molecular mechanisms by which BTZ regulates the growth of DLBCL cells remain largely unknown. Increasing evidence has suggested that microRNAs (miRNAs) are novel targets of anti-cancer drugs to modulate the progression of cancers. Here, we showed BTZ treatment significantly inhibited the proliferation of DLBCL CRL-2630 cells. Mechanistically, exposure of BTZ up-regulated the expression of miR-198 in DLBCL cells. Depletion of miR-198 significantly reversed the inhibitory effect of BTZ on the proliferation of CRL-2630 cells. To further characterize the involvement of miR-198 in BTZ-induced growth defects of CRL-2630 cells, the downstream targets of miR-198 were predicted with the bioinformatics tools. The results showed that miR-198 bound the 3'-untranslated region (UTR) of the high mobility group AT-hook 1 (HMGA1) and suppressed the expression of HMGA1 in DLBCL cells. Consistently, BTZ treatment decreased the level of HMAG1 and inhibited the migration of DLBCL cells. Our results provided the possible mechanism by which BTZ suppressed the growth of DLBCL cells.

Combined Biomarkers Composed of Environment and Genetic Factors in Stroke

It was widely accepted that stroke onset was the result of interactions between environment and genetic factors. However, the combined biomarkers covering environment and genetic factors and their interplay information in stroke were still lacking. In this study, we proposed a framework to identify the targeting or indicating role each factor played in the combined stroke biomarkers. A combined set of 36 biomarkers were identified based on evaluation and importance scores. Validations on three independent microarray data sets justified that the obtained markers were pervasively effective in discriminating stroke patients of different stages from healthy people on genetic levels. 8 and 3 genetic factors were identified as biomarkers in the acute and recovery phases of stroke, respectively. For example, the expression changing of SERPINH1 only appeared in the acute phase of stroke showing its targeting role in the combined biomarker. Compared with this, 11 genetic factors such as MMP9 were found to be differentially expressed in both acute and recovery phases of stroke showing their indicating roles in stroke. Functional analyses further revealed that the biomarkers could be grouped into 4 closely related processes of stroke including prevention, occurrence, processing, and recovery, respectively. These results indicated that the adoption of interactions between environment and genetic factors would be helpful in selecting robust and biologically relevant biomarkers, which cast a new insight for stroke biomarker identification.

MiRAR-miRNA Activity Reporter for Living Cells

microRNA (miRNA) activity and regulation are of increasing interest as new therapeutic targets. Traditional approaches to assess miRNA levels in cells rely on RNA sequencing or quantitative PCR. While useful, these approaches are based on RNA extraction and cannot be applied in real-time to observe miRNA activity with single-cell resolution. We developed a green fluorescence protein (GFP)-based reporter system that allows for a direct, real-time readout of changes in miRNA activity in live cells. The miRNA activity reporter (MiRAR) consists of GFP fused to a 3&prime; untranslated region containing specific miRNA binding sites, resulting in miRNA activity-dependent GFP expression. Using qPCR, we verified the inverse relationship of GFP fluorescence and miRNA levels. We demonstrated that this novel optogenetic reporter system quantifies cellular levels of the tumor suppressor miRNA let-7 in real-time in single Human embryonic kidney 293 (HEK 293) cells. Our data shows that the MiRAR can be applied to detect changes in miRNA levels upon disruption of miRNA degradation pathways. We further show that the reporter could be adapted to monitor another disease-relevant miRNA, miR-122. With trivial modifications, this approach could be applied across the miRNome for quantification of many specific miRNA in cell cultures, tissues, or transgenic animal models.

Circulating MicroRNAs as Biomarkers in Diffuse Large B-cell Lymphoma: A Pilot Prospective Longitudinal Clinical Study

Objectives:

Diffuse large B-cell lymphoma (DLBCL) is highly heterogeneous in terms of phenotype and treatment response in patients. These characteristics make the prognosis difficult to establish and hinder the use of new personalized treatments in clinical practice. In this context, there is currently a need to define new biomarkers enabling a better definition of DLBCL subtypes, prognosis evaluation, and an overview of the resistance to chemotherapeutics. The aim of this study was to evaluate the use of microRNAs found in plasma from patients with DLBCL as biomarkers of tumor evolution in these patients.

Method:

For this purpose, a plasma biobank was created with samples from patients with DLBCL. The evolution of the level of selected microRNAs during treatment has been studied. A total of 19 patients with DLBCL were included in this pilot mono-centered study and a total of 68 samples were analyzed.

Results:

The first step of this study was the selection of the microRNAs to be quantified in all the samples of the biobank and that could potentially be used as biomarkers. To this end, quantification of 377 microRNAs was performed on the plasma samples of 2 selected patients with DLBCL and 1 healthy donor with no history of cancer. Among the 377 microRNAs evaluated, 7 were selected and analyzed in the entire biobank.

Conclusions:

This study highlighted 5 circulating microRNAs whose plasma levels would be worth further investigating for the characterization of DLBCL evolution in patients. MiR-21 and miR-197 had a significant higher plasmatic level in patients with tumors unresponsive to treatment. With a higher plasma level in patients with complete remission, miR-19b, miR-20a, and miR-451 could enable to differentiate, at the remission review, patients with residual tumor, from patients with complete remission.

Up-regulation of miR-122 protects against neuronal cell death in ischemic stroke through the heat shock protein 70-dependent NF-κB pathway by targeting FOXO3

Dysfunction of the microRNA (miRNA) network has been emerging as a main regulator in ischemic stroke. Recently, studies have linked the deregulation of miR-122 to ischemic stroke. However, the specific role and molecular mechanism of miR-122 in ischemic stroke remain to be further investigated. Here, we found that miR-122 was decreased in mouse N2A neuroblastoma (N2A) cells after oxygen-glucose deprivation (OGD) and mouse brain after transient middle cerebral artery occlusion (MCAO). OGD treatment significantly increased N2A cell death and Caspase-3 activity, and decreased Bcl-2 protein expression. In addition, MCAO treatment induced severe mouse brain infarction, mitochondrial reactive oxygen species (ROS) production, and long-term neurological deficit. Gain-of-miR-122 function significantly suppressed OGD- and MCAO-induced injures in vitro and in vivo. Subsequently, miR-122 was validated to directly bind to the predicted 3'-untranslated region (3'-UTR) of FOXO3 gene, and the inhibitory effects of miR-122 on ischemic injury in vitro and in vivo were overturned by FOXO3 overexpression. Moreover, our results further revealed that miR-122-FOXO3 axis functioned via the heat shock protein 70 (HSP-70)-mediated NF-κB pathway. Collectively, our data suggest that miR-122 inhibits ischemic neuronal death through the HSP-70-dependent NF-κB pathway by targeting FOXO3. These findings raise the possibility that this regulatory net may contribute to the pathogenesis of the ischemic brain injury in stroke.

Ubiquitin-specific protease 2 decreases p53-dependent apoptosis in cutaneous T-cell lymphoma

Treatment of advanced cutaneous T-cell lymphomas (CTCL) is challenging because they are resistant to conventional chemotherapy. USP2 has been shown to promote resistance to chemotherapeutic agents in several cancer models.We show here USP2 is expressed in quiescent and activated T-cells and its expression is 50% lower in CTCL cell lines (MyLa2000, SeAx and Hut-78) than in normal T-cells. USP2 is expressed in neoplastic cells in early, plaque-stage mycosis fungoides (MF) and is downregulated in advanced tumor stages. Upon treatment with psoralen with UVA (PUVA) or a p53 activator, nutlin3a, USP2 expression is significantly increased in MyLa2000 (p53wt/wt), but not in SeAx (p53mut) or Hut-78 (p53-/-). USP2 knockdown decreases MyLa2000 cell viability after PUVA by 50% but not Hut-78, suggesting that the function of USP2 in CTCL cells is p53-dependent. Furthermore, USP2 knockdown results in a decreased Mdm2 expression and upregulation of p53. Taken together, our findings suggest that USP2 stabilizes Mdm2 which antagonizes pro-apoptotic activity of p53 and possibly contributes to therapeutic resistance in CTCL.

The impact of microRNA-122 and its target gene Sestrin-2 on the protective effect of ghrelin in angiotensin II-induced cardiomyocyte apoptosis

Ghrelin with n-octanoylated serine 3 residue is a peptide hormone with well-known cardioprotective properties. MicroRNA-122 is associated with the pathogenesis of many cardiovascular diseases, including apoptosis and was found highly increased in our previous rat model of post-myocardial infarction heart failure. In this study, we aimed to identify the target gene of microRNA-122 and to evaluate their impacts on the protective effect of acylated ghrelin in angiotensin II-induced apoptosis. The results showed that microRNA-122 was upregulated in the angiotensin II administration group accompanied by increased cell apoptosis, which were both reversed by ghrelin. Furthermore, microRNA-122 mimics upregulated numerous pro-apoptotic genes and increased apoptosis. The luciferase activity assay revealed Sestrin-2 as a direct target of microRNA-122. The expression of Sestrin-2 was downregulated by angiotensin II and upregulated by co-treatment with ghrelin. Inhibition of microRNA-122 and overexpression of Sestrin-2 alleviated apoptosis which was further reduced upon administered of ghrelin. Together, these results indicated that Sestrin-2 expression is inhibited by microRNA-122 and that this inhibition is involved in the protective effect of ghrelin and angiotensin II-induced apoptosis. We also found that microRNA-122 influenced several apoptosis pathways including the caspase cascade reaction and death receptor-mediated pathways. Collectively, our data reveal that microRNA-122 and its target gene Sestrin-2, under the regulation of angiotensin II and ghrelin, are important players in cardiomyocyte apoptosis. We therefore believe that microRNA-122 and Sestrin-2 can be developed as potential therapeutic targets against apoptosis in cardiovascular diseases.

Inhibition of microRNA-122 and overexpression of Sestrin-2 alleviated angiotensin II-induced cardiomyocyte apoptosis and enhanced the protective effect of ghrelin.

EGBMMDA: Extreme Gradient Boosting Machine for MiRNA-Disease Association prediction

Associations between microRNAs (miRNAs) and human diseases have been identified by increasing studies and discovering new ones is an ongoing process in medical laboratories. To improve experiment productivity, researchers computationally infer potential associations from biological data, selecting the most promising candidates for experimental verification. Predicting potential miRNA–disease association has become a research area of growing importance. This paper presents a model of Extreme Gradient Boosting Machine for MiRNA-Disease Association (EGBMMDA) prediction by integrating the miRNA functional similarity, the disease semantic similarity, and known miRNA–disease associations. The statistical measures, graph theoretical measures, and matrix factorization results for each miRNA-disease pair were calculated and used to form an informative feature vector. The vector for known associated pairs obtained from the HMDD v2.0 database was used to train a regression tree under the gradient boosting framework. EGBMMDA was the first decision tree learning-based model used for predicting miRNA–disease associations. Respectively, AUCs of 0.9123 and 0.8221 in global and local leave-one-out cross-validation proved the model’s reliable performance. Moreover, the 0.9048 ± 0.0012 AUC in fivefold cross-validation confirmed its stability. We carried out three different types of case studies of predicting potential miRNAs related to Colon Neoplasms, Lymphoma, Prostate Neoplasms, Breast Neoplasms, and Esophageal Neoplasms. The results indicated that, respectively, 98%, 90%, 98%, 100%, and 98% of the top 50 predictions for the five diseases were confirmed by experiments. Therefore, EGBMMDA appears to be a useful computational resource for miRNA–disease association prediction.

miR-122 promotes metastasis of clear-cell renal cell carcinoma by downregulating Dicer

Although overall downregulation of microRNAs (miRNAs) is a general feature of clear-cell renal cell carcinoma (ccRCC), several miRNAs are consistently upregulated, among which miR-122 was markedly increased in ccRCC tissues. Our study aims to determine the functional importance and underlying mechanism of miR-122 in ccRCC metastasis. Here, we demonstrate that the expression of miR-122 increased in ccRCC tissues, and higher miR-122 expression was found in ccRCC tissues with metastatic disease than in those without metastasis. The increased miR-122 levels were associated with poor metastasis-free survival in ccRCC patients with localized disease. Dicer was validated as a direct functional target of miR-122. Overexpression of miR-122 promoted migration and invasion of ccRCC cells in vitro and metastatic behavior of ccRCC cells in vivo. Inhibition of miR-122 attenuated this metastatic phenotype in vitro. Importantly, miR-122 exerted its pro-metastatic properties in ccRCC cells by downregulating Dicer and its downstream effector, the miR-200 family, thereby inducing epithelial-mesenchymal transition (EMT). Our results suggest an important role of the miR-122/Dicer/miR-200s/EMT pathway in ccRCC metastasis. Furthermore, miR-122 may serve as a biomarker for discriminating ccRCC with metastatic potential.

The IGF-1R/AKT pathway has opposing effects on Nutlin-3a-induced apoptosis

Nutlin-3a is a small molecule MDM2 antagonist and potent activator of wild-type p53. Nutlin-3a disrupts MDM2 binding to p53, thus increasing p53 levels and allowing p53 to inhibit proliferation or induce cell death. Factors that control sensitivity to Nutlin-3a-induced apoptosis are incompletely understood. In this study we isolated cisplatin-resistant clones from MHM cells, an MDM2-amplified and p53 wild-type osteosarcoma cell line. Cisplatin resistance in these clones resulted in part from heightened activation of the IGF-1R/AKT pathway. Interestingly, these cisplatin resistant clones showed hyper-sensitivity to Nutlin-3a induced apoptosis. Increased Nutlin-3a sensitivity was associated with reduced authophagy flux and a greater increase in p53 levels in response to Nutlin-3a treatment. IGF-1R and AKT inhibitors further increased apoptosis by Nutlin-3a in parental MHM cells and the cisplatin-resistant clones, confirming IGF-1R/AKT signaling promotes apoptosis resistance. However, IGF-1R and AKT inhibitors also reduced p53 accumulation in Nutlin-3a treated cells and increased autophagy flux, which we showed can promote apoptosis resistance. We conclude the IGF-1R/AKT pathway has opposing effects on Nutlin-3a-induced apoptosis. First, it can inhibit apoptosis, consistent with its well-established role as a survival-signaling pathway. Second, it can enhance Nutlin-3a induced apoptosis through a combination of maintaining p53 levels and inhibiting pro-survival autophagy.

Comparative analysis of the microRNA transcriptome between yak and cattle provides insight into high-altitude adaptation

Extensive and in-depth investigations of high-altitude adaptation have been carried out at the level of morphology, anatomy, physiology and genomics, but few investigations focused on the roles of microRNA (miRNA) in high-altitude adaptation. We examined the differences in the miRNA transcriptomes of two representative hypoxia-sensitive tissues (heart and lung) between yak and cattle, two closely related species that live in high and low altitudes, respectively. In this study, we identified a total of 808 mature miRNAs, which corresponded to 715 pre-miRNAs in the two species. The further analysis revealed that both tissues showed relatively high correlation coefficient between yak and cattle, but a greater differentiation was present in lung than heart between the two species. In addition, miRNAs with significantly differentiated patterns of expression in two tissues exhibited co-operation effect in high altitude adaptation based on miRNA family and cluster. Functional analysis revealed that differentially expressed miRNAs were enriched in hypoxia-related pathways, such as the HIF-1α signaling pathway, the insulin signaling pathway, the PI3K-Akt signaling pathway, nucleotide excision repair, cell cycle, apoptosis and fatty acid metabolism, which indicated the important roles of miRNAs in high altitude adaptation. These results suggested the diverse degrees of miRNA transcriptome variation in different tissues between yak and cattle, and suggested extensive roles of miRNAs in high altitude adaptation.

The Role of MDM2 in Promoting Genome Stability versus Instability

In cancer, the mouse double minute 2 (MDM2) is an oncoprotein that contributes to the promotion of cell growth, survival, invasion, and therapeutic resistance. The impact of MDM2 on cell survival versus cell death is complex and dependent on levels of MDM2 isoforms, p53 status, and cellular context. Extensive investigations have demonstrated that MDM2 protein–protein interactions with p53 and other p53 family members (p63 and p73) block their ability to function as transcription factors that regulate cell growth and survival. Upon genotoxic insults, a dynamic and intricately regulated DNA damage response circuitry is activated leading to release of p53 from MDM2 and activation of cell cycle arrest. What ensues following DNA damage, depends on the extent of DNA damage and if the cell has sufficient DNA repair capacity. The well-known auto-regulatory loop between p53-MDM2 provides an additional layer of control as the cell either repairs DNA damage and survives (i.e., MDM2 re-engages with p53), or undergoes cell death (i.e., MDM2 does not re-engage p53). Furthermore, the decision to live or die is also influenced by chromatin-localized MDM2 which directly interacts with the Mre11-Rad50-Nbs1 complex and inhibits DNA damage-sensing giving rise to the potential for increased genome instability and cellular transformation.

IL-22-induced miR-122-5p promotes keratinocyte proliferation by targeting Sprouty2

Psoriasis is a common inflammatory skin disease, but the exact pathogenesis is largely unknown. Interleukin-22 (IL-22) has demonstrated its vital role in T-cell-mediated immune response by interacting with keratinocytes in the pathogenesis of psoriasis. Here, we showed the differentially expressed miRNAs and their potential targets in HaCaT cells stimulated by IL-22 using miRNA and mRNA microarrays. We revealed a total of 20 significantly changed (more than twofold) miRNAs in HaCaT cells and validated the results with quantitative reverse transcriptase PCR (qRT-PCR). We demonstrated that miR-122-5p was up-regulated both in HaCaT cells stimulated by IL-22 and in psoriatic lesions. Then, we aimed to investigate the biological roles and potential mechanism of miR-122-5p in keratinocytes. As a result, CCK-8 assay indicated that overexpression of miR-122-5p in keratinocytes promoted proliferation and conversely inhibition of endogenous miR-122-5p suppressed proliferation. According to the microarray analysis, we assumed that Sprouty2 (Spry2), a negative regulator of extracellular signal regulated kinase/mitogen-activated protein kinase signalling pathway, was a direct target gene of miR-122-5p. We found that the staining of Spry2 in cytoplasm was mainly localized in both basal and suprabasal layers of epidermis and showed a markedly decreased expression in psoriasis than in normal control by immunohistochemistry. Luciferase reporter and Western blot assays in HaCaT cells demonstrated that Spry2 was a direct target gene of miR-122-5p. In conclusion, IL-22-induced miR-122-5p promotes keratinocyte proliferation possibly by downregulating the expression of Spry2 thus playing important roles in the pathogenesis of psoriasis.

MiR-122 promotes renal cancer cell proliferation by targeting Sprouty2

MicroRNAs are short non-coding RNAs, which have been implicated in several biological processes. Aberrant expression of the microRNA miR-122 has frequently been reported in malignant cancers. However, the mechanism underlying the effects of miR-122 in renal cell carcinoma remains unknown. The aim of this study was to determine the biological function of miR-122 in renal cell carcinoma and to identify a novel molecular target regulated by miR-122. We measured the expression levels of Sprouty2 in six renal cell carcinoma tissue samples and adjacent non-tumor tissues by western blot analysis. We then used reverse transcription polymerase chain reaction to measure miR-122 levels in 40 primary renal cell carcinoma and adjacent non-malignant tissue samples. The effects of miR-122 down-regulation or Sprouty2 knockdown were evaluated via Cell Counting Kit-8 assay, flow cytometry, and western blot analysis. The relationship between miR-122 and Sprouty2 was determined using dual-luciferase reporter assays. Sprouty2 was down-regulated in renal cell carcinoma tissue samples compared with adjacent normal tissue. In contrast, miR-122 was up-regulated in primary renal cell carcinoma tissue samples compared with adjacent normal tissue samples. Down-regulation of miR-122 substantially weakened the proliferative ability of renal cell carcinoma cell lines in vitro. In contrast, Sprouty2 knockdown promoted the in vitro proliferation of renal cell carcinoma cell lines. The spry2 gene could therefore be a direct target of miR-122. In conclusion, miR-122 could act as a tumor promoter and potentially target Sprouty2. MiR-122 promotes renal cell carcinoma cell proliferation, migration, and invasion and could be a molecular target in novel therapies for renal cell carcinoma.

miR-600 inhibits cell proliferation, migration and invasion by targeting p53 in mutant p53-expressing human colorectal cancer cell lines

Mutations of the tumor protein p53 gene, a tumor suppressor, are one of the most frequent genetic alterations observed in cancer. It has been reported that mutations in p53 result in the loss of wild-type p53 activity, and the gain of novel oncogenic properties that promote tumor growth and progression. Recent studies have demonstrated that a number of microRNAs (miRs) are involved in the post-transcriptional regulation of p53. The present study demonstrates that miR-600 is a direct negative regulator of p53 through binding a site in the 3' untranslated region of p53 mRNA in human colorectal cancer (CRC) cells. Overexpression of miR-600 by lentiviral-mediated transduction decreased endogenous levels of p53 protein and inhibited cell proliferation, migration and invasion in mutant p53-expressing human CRC cell lines (SW480, SW620 and DLD-1) in vitro. In addition, silencing of p53 with small interfering RNA led to a similar phenotype. Furthermore, overexpression of miR-600 or p53 knockdown suppressed the expression of matrix metalloproteinase 9, and promoted the expression of E-cadherin and β-catenin. The results of the current study demonstrate that miR-600 is an important negative regulator of p53, and suggest that targeting mutant p53 using lentiviral-mediated miR-600 overexpression is a promising therapeutic strategy for the treatment of CRCs with p53 mutations.

Hepatitis C virus has a genetically determined lymphotropism through co-receptor B7.2

B-cell infection by hepatitis C virus (HCV) has been a controversial topic. To examine whether HCV has a genetically determined lymphotropism through a co-receptor specific for the infection by lymphotropic HCV, we established an infectious clone and chimeric virus of hepatotropic and lymphotropic HCV strains derived from an HCV-positive B-cell lymphoma. The viral envelope and 5'-UTR sequences of the lymphotropic HCV strain were responsible for the lymphotropism. Silencing of the virus sensor, RIGI, or overexpression of microRNA-122 promoted persistent viral replication in B cells. By cDNA library screening, we identified an immune cell-specific, co-stimulatory receptor B7.2 (CD86) as a co-receptor of lymphotropic HCV. Infection of B cells by HCV inhibited the recall reaction to antigen stimulation. Together, a co-receptor B7.2 enabled lymphotropic HCV to infect memory B cells, leading to inhibition of memory B-cell function and persistent HCV infection in HCV-infected hosts.

MicroRNA: Defining a new niche in Leukemia

MicroRNAs (miRNAs) are endogenous short non-coding RNAs found to play key roles in the pathogenesis of leukemia. Apart from being traditionally identified as modulators of oncogenes, the potential roles of miRNAs seems to be growing with novel and recent findings among different subtypes of hematological malignancies. Leukemia is one of the earliest malignancies to be linked to abnormal expression of miRNAs. However, a clear understanding of the involvement of miRNAs in intricate mechanisms of leukemogenesis is still a necessity. This review summarizes the multiple roles of miRNAs in the pathogenesis of leukemia and highlights major research findings contributing to these aspects.

Effect of Mir-122 on Human Cholangiocarcinoma Proliferation, Invasion, and Apoptosis Through P53 Expression

Background

Bile duct carcinoma is a common digestive tract tumor with high morbidity and mortality. As a kind of important non-coding RNA, microRNA (miR) plays an important role in post-transcriptional regulation. MiR-122 is the most abundant miR in the liver. Multiple studies have shown that miR-122 level is reduced in a variety of liver tumors and can be used as a specific marker for liver injury. P53 is a classic tumor suppressor gene that can induce tumor cell apoptosis through various pathways. Whether miR-122 affects p53 in bile duct carcinoma still needs investigation.

Material/Methods

miR inhibitor or mimics was transfected to bile duct carcinoma cells to evaluate its function on proliferation, invasion, apoptosis, and p53 expression.

Results

MiR-122 overexpression reduced cell invasion and migration ability, and inhibited cell apoptosis and p53 expression. Inhibiting miR-122 caused the opposite results.

Conclusions

Upregulating miR-122 can suppress bile duct carcinoma cell proliferation and induce apoptosis. MiR-122 could be used as a target for bile duct carcinoma treatment, which provides a new strategy for cholangiocarcinoma patients.

miR-155 as a Biomarker in B-Cell Malignancies

MicroRNAs have the potential to be useful biomarkers in the development of individualized treatment since they are easy to detect, are relatively stable during sample handling, and are important determinants of cellular processes controlling pathogenesis, progression, and response to treatment of several types of cancers including B-cell malignancies. miR-155 is an oncomiR with a crucial role in tumor initiation and development of several B-cell malignancies. The present review elucidates the potential of miR-155 as a diagnostic, prognostic, or predictive biomarker in B-cell malignancies using a systematic search strategy to identify relevant literature. miR-155 was upregulated in several malignancies compared to nonmalignant controls and overexpression of miR-155 was further associated with poor prognosis. Elevated expression of miR-155 shows potential as a diagnostic and prognostic biomarker in diffuse large B-cell lymphoma and chronic lymphocytic leukemia. Additionally, in vitro and in vivo studies suggest miR-155 as an efficient therapeutic target, supporting its oncogenic function. The use of inhibiting anti-miR structures indicates promising potential as novel anticancer therapeutics. Reports from 53 studies prove that miR-155 has the potential to be a molecular tool in personalized medicine.