MiR-15 and miR-16 are direct transcriptional targets of E2F1 that limit E2F-induced proliferation by targeting cyclin E

miR-424-3p promotes metastasis of hepatocellular carcinoma via targeting the SRF-STAT1/2 axis

Although emerging evidence has established the roles of miRNAs in hepatocellular carcinoma (HCC), the global functional implication of miRNAs in this malignancy remains largely uncharacterized. Here, we aim to systematically identify novel miRNAs involved in HCC and clarify the function and mechanism of specific novel candidate miRNA(s) in this malignancy. Through an integrative omics approach, we identified ten HCC-associated functional modules and a collection of candidate miRNAs. Among them, we demonstrated that miR-424-3p, exhibiting strong associations with extracellular matrix (ECM), promotes HCC cells migration and invasion in vitro and facilitates HCC metastasis in vivo. We further demonstrated that SRF is a direct functional target of miR-424-3p, and is required for the oncogenic activity of miR-424-3p. Finally, we found that miR-424-3p reduces the interferon pathway by attenuating the transactivation of SRF on STAT1/2 and IRF9 genes, which in turn enhances the matrix metalloproteinases (MMPs)-mediated ECM remodeling. This study provides comprehensive functional relevance of miRNAs in HCC by an integrative omics analysis, and further clarifies that miR-424-3p in ECM functional module plays an oncogenic role via reducing the SRF-STAT1/2 axis in this malignancy.

Biomarkers or biotargets? Using competition to lure cancer cells into evolutionary traps

Background and Objectives

Cancer biomarkers provide information on the characteristics and extent of cancer progression and help inform clinical decision-making. However, they can also play functional roles in oncogenesis, from enabling metastases and inducing angiogenesis to promoting resistance to chemotherapy. The resulting evolution could bias estimates of cancer progression and lead to suboptimal treatment decisions.

Methodology

We create an evolutionary game theoretic model of cell-cell competition among cancer cells with different levels of biomarker production. We design and simulate therapies on top of this pre-existing game and examine population and biomarker dynamics.

Results

Using total biomarker as a proxy for population size generally underestimates chemotherapy efficacy and overestimates targeted therapy efficacy. If biomarker production promotes resistance and a targeted therapy against the biomarker exists, this dynamic can be used to set an evolutionary trap. After chemotherapy selects for a high biomarker-producing cancer cell population, targeted therapy could be highly effective for cancer extinction. Rather than using the most effective therapy given the cancer's current biomarker level and population size, it is more effective to 'overshoot' and utilize an evolutionary trap when the aim is extinction. Increasing cell-cell competition, as influenced by biomarker levels, can help prime and set these traps.

Conclusion and Implications

Evolution of functional biomarkers amplify the limitations of using total biomarker levels as a measure of tumor size when designing therapeutic protocols. Evolutionarily enlightened therapeutic strategies may be highly effective, assuming a targeted therapy against the biomarker is available.

New roles for AP-1/JUNB in cell cycle control and tumorigenic cell invasion via regulation of cyclin E1 and TGF-β2

BACKGROUND

JUNB transcription factor contributes to the formation of the ubiquitous transcriptional complex AP-1 involved in the control of many physiological and disease-associated functions. The roles of JUNB in the control of cell division and tumorigenic processes are acknowledged but still unclear.

RESULTS

Here, we report the results of combined transcriptomic, genomic, and functional studies showing that JUNB promotes cell cycle progression via induction of cyclin E1 and repression of transforming growth factor (TGF)-β2 genes. We also show that high levels of JUNB switch the response of TGF-β2 stimulation from an antiproliferative to a pro-invasive one, induce endogenous TGF-β2 production by promoting TGF-β2 mRNA translation, and enhance tumor growth and metastasis in mice. Moreover, tumor genomic data indicate that JUNB amplification associates with poor prognosis in breast and ovarian cancer patients.

CONCLUSIONS

Our results reveal novel functions for JUNB in cell proliferation and tumor aggressiveness through regulation of cyclin E1 and TGF-β2 expression, which might be exploited for cancer prognosis and therapy.

A Regulatory Loop Involving miR-200c and NF-κB Modulates Mortalin Expression and Increases Cisplatin Sensitivity in an Ovarian Cancer Cell Line Model

Ovarian cancer is currently the most lethal gynecological cancer. At present, primary debulking surgery combined with platinum-based chemotherapy is the standard treatment strategy for ovarian cancer. Although cisplatin-based chemotherapy has greatly improved the prognosis of patients, the subsequent primary or acquired drug resistance of cancer cells has become an obstacle to a favorable prognosis. Mortalin is a chaperone that plays an important role in multiple cellular and biological processes. Our previous studies have found that mortalin is associated with the proliferation and migration of ovarian cancer cells and their resistance to cisplatin-based chemotherapy. In this study, microRNA (miR)-200b/c downregulated mortalin expression and inhibited the proliferation and migration of the paired cisplatin-sensitive (A2780S) and cisplatin-resistant (A2780CP) epithelial ovarian cancer cell lines. Moreover, miR-200c increased the sensitivity of ovarian cancer cells to cisplatin treatment by regulating mortalin levels. Nuclear factor (NF)-κB directly regulated mortalin and miR-200b/c expression levels, while NF-κB and miR-200b/c jointly regulated the expression of mortalin. The combination of cisplatin and miR-200c significantly enhanced the therapeutic effects on ovarian cancer in vivo, suggesting that miR-200c may serve as a potential therapeutic agent for ovarian cancer.

E2F1 regulates miR-215-5p to aggravate paraquat-induced pulmonary fibrosis via repressing BMPR2 expression

Background

Pulmonary fibrosis is considered to be an irreversible lung injury, which can be caused by paraquat (PQ) poisoning. MiRNAs have been demonstrated crucial roles in pulmonary fibrosis caused by numerous approaches including PQ induction. The purpose of this study was to investigate the role and the underlying mechanism of miR-215 in PQ-induced pulmonary fibrosis.

Methods

The cell and animal models of pulmonary fibrosis were established through PQ intervention. Cell viability was performed to test by MTT assay. Immunofluorescence assay was used to detect COL1A1 expression and its location. The relationships among E2F1, miR-215-5p, and BMPR2 were validated by dual luciferase reporter gene assay, chromatin immunoprecipitation and RNA-binding protein immunoprecipitation. Lung morphology was evaluated by hematoxylin and eosin staining.

Results

MiR-215-5p was upregulated in PQ-induced pulmonary fibrosis in vitro and in vivo. MiR-215-5p silencing relieved PQ-induced pulmonary fibrosis progression by enhancing cell viability and reducing the expression of fibrosis-related markers (COL1A1, COL3A1, and α-SMA). Mechanistically, miR-215-5p directly targeted BMRP2. BMPR2 knockdown abolished the suppressive effects of miR-215-5p knockdown on PQ-induced pulmonary fibrosis. In addition, E2F1 interacted with miR-215-5p promoter and positively regulated miR-215-5p expression. E2F1 downregulation reduced miR-215-5p level and promoted BMPR2 level via regulating TGF-β/Smad3 pathway, and then suppressed PQ-induced pulmonary fibrosis, whereas these effects were compromised by miR-215-5p sufficiency.

Conclusion

MiR-215-5p was activated by E2F1 to repress BMPR2 expression and activate TGF-β/Smad3 pathway, which aggravated PQ-induced pulmonary fibrosis progression. Targeting the E2F1/miR-215-5p/BMPR2 axis might be a new approach to alleviate PQ-induced pulmonary fibrosis.

The role of microRNAs in neurodegenerative diseases: a review

MicroRNAs (miRNAs) are non-coding RNAs which are essential post-transcriptional gene regulators in various neuronal degenerative diseases and playact a key role in these physiological progresses. Neurodegenerative diseases, such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, multiple sclerosis, and, stroke, are seriously threats to the life and health of all human health and life kind. Recently, various studies have reported that some various miRNAs can regulate the development of neurodegenerative diseases as well as act as biomarkers to predict these neuronal diseases conditions. Endogenic miRNAs such as miR-9, the miR-29 family, miR-15, and the miR-34 family are generally dysregulated in animal and cell models. They are involved in regulating the physiological and biochemical processes in the nervous system by targeting regulating different molecular targets and influencing a variety of pathways. Additionally, exogenous miRNAs derived from homologous plants and defined as botanmin, such as miR2911 and miR168, can be taken up and transferred by other species to be and then act analogously to endogenic miRNAs to regulate the physiological and biochemical processes. This review summarizes the mechanism and principle of miRNAs in the treatment of some neurodegenerative diseases, as well as discusses several types of miRNAs which were the most commonly reported in diseases. These miRNAs could serve as a study provided some potential biomarkers in neurodegenerative diseases might be an ideal and/or therapeutic targets for neurodegenerative diseases. Finally, the role accounted of the prospective exogenous miRNAs involved in mammalian diseases is described.

DISE/6mer seed toxicity-a powerful anti-cancer mechanism with implications for other diseases

micro(mi)RNAs are short noncoding RNAs that through their seed sequence (pos. 2-7/8 of the guide strand) regulate cell function by targeting complementary sequences (seed matches) located mostly in the 3' untranslated region (3' UTR) of mRNAs. Any short RNA that enters the RNA induced silencing complex (RISC) can kill cells through miRNA-like RNA interference when its 6mer seed sequence (pos. 2-7 of the guide strand) has a G-rich nucleotide composition. G-rich seeds mediate 6mer Seed Toxicity by targeting C-rich seed matches in the 3' UTR of genes critical for cell survival. The resulting Death Induced by Survival gene Elimination (DISE) predominantly affects cancer cells but may contribute to cell death in other disease contexts. This review summarizes recent findings on the role of DISE/6mer Seed Tox in cancer; its therapeutic potential; its contribution to therapy resistance; its selectivity, and why normal cells are protected. In addition, we explore the connection between 6mer Seed Toxicity and aging in relation to cancer and certain neurodegenerative diseases.

E2F transcription factor 1 elevates cyclin D1 expression by suppressing transcription of microRNA-107 to augment progression of glioma

BACKGROUND

Dysregulation of microRNAs has been frequently implicated in the progression of human diseases, including glioma. This study aims to explore the interaction between E2F transcription factor 1 (E2F1) and miR-107 in the progression of glioma.

METHODS

Expression of miR-107 in glioma tissues and cells was examined. Putative binding sites between E2F1 and the promoter region of miR-107, and between miR-107 and cyclin D1 (CCND1) mRNA were predicted via bioinformatic systems and validated via chromatin immunoprecipitation and luciferase reporter gene assays. Altered expression of miR-107, E2F1, and CCND1 was introduced in A172 and T98G cells to examine their roles in cell growth and the activity of the Wnt/β-catenin signaling. In vivo experiments were performed by injecting cells in nude mice.

RESULTS

miR-107 was poorly expressed, whereas E2F1 and CCND1 were highly expressed in glioma tissues and cells. E2F1 bound to the promoter region of miR-107 to induce transcriptional repression, and miR-107 directly bound to CCND1 mRNA to reduce its expression. Overexpression of miR-107 reduced proliferation, migration and invasion, and augmented apoptosis of glioma cells, and it reduced activity of the Wnt/β-catenin pathway. The anti-tumorigenic roles of miR-107 were blocked by E2F1 or CCND1 overexpression. Similar results were reproduced in vivo where miR-107 overexpression or E2F1 inhibition blocked tumor growth in nude mice.

CONCLUSION

This study suggested that E2F1 reduces miR-107 transcription to induce CCND1 upregulation, which leads to progression of glioma via Wnt/β-catenin signaling activation.

Jak HPV wysokiego ryzyka indukuje optymalne środowisko dla własnej replikacji w różnicującym się nabłonku

Wirusy brodawczaka ludzkiego (HPV) są często czynnikami wywołującymi niegroźne dla człowieka infekcje, ale przetrwałe zakażenie niektórymi typami HPV jest poważnym zagrożeniem dla zdrowia, ponieważ jest związane z wieloma nowotworami, w tym z rakiem szyjki macicy oraz rosnącą liczbą nowotworów głowy i szyi. Cykl replikacyjny HPV jest ściśle zależny od różnicowania komórek wielowarstwowego nabłonka, co oznacza, że genom wirusa musi być replikowany za pomocą różnych mechanizmów na różnych etapach różnicowania komórek. Ustanowienie infekcji i utrzymywanie genomu wirusa zachodzi w proliferujących komórkach nabłonka, gdzie dostępność czynników replikacji jest optymalna dla wirusa. Jednak produktywna faza cyklu rozwojowego wirusa, w tym produktywna replikacja, późna ekspresja genów i wytwarzanie wirionów, zachodzi w wyniku różnicowania się nabłonka w komórkach, które prawidłowo opuszczają cykl komórkowy. Wirus wykorzystuje wiele szlaków sygnalizacyjnych komórki, w tym odpowiedź na uszkodzenia DNA (DDR, DNA damage response) do realizacji produktywnej replikacji własnego genomu. Zrozumienie mechanizmów związanych z cyklem replikacyjnym HPV jest potrzebne do ustalenia właściwego podejścia terapeutycznego do zwalczania chorób powodowanych przez HPV.

MicroRNAs and the DNA damage response: How is cell fate determined?

It is becoming clear that the DNA damage response orchestrates an appropriate response to a given level of DNA damage, whether that is cell cycle arrest and repair, senescence or apoptosis. It is plausible that the alternative regulation of the DNA damage response (DDR) plays a role in deciding cell fate following damage. MicroRNAs (miRNAs) are associated with the transcriptional regulation of many cellular processes. They have diverse functions, affecting, presumably, all aspects of cell biology. Many have been shown to be DNA damage inducible and it is conceivable that miRNA species play a role in deciding cell fate following DNA damage by regulating the expression and activation of key DDR proteins. From a clinical perspective, miRNAs are attractive targets to improve cancer patient outcomes to DNA-damaging chemotherapy. However, cancer tissue is known to be, or to become, well adapted to DNA damage as a means of inducing chemoresistance. This frequently results from an altered DDR, possibly owing to miRNA dysregulation. Though many studies provide an overview of miRNAs that are dysregulated within cancerous tissues, a tangible, functional association is often lacking. While miRNAs are well-documented in 'ectopic biology', the physiological significance of endogenous miRNAs in the context of the DDR requires clarification. This review discusses miRNAs of biological relevance and their role in DNA damage response by potentially 'fine-tuning' the DDR towards a particular cell fate in response to DNA damage. MiRNAs are thus potential therapeutic targets/strategies to limit chemoresistance, or improve chemotherapeutic efficacy.

The role of noncoding RNAs in pituitary adenoma

Pituitary adenomas (PAs) are common cranial tumors that affect the quality of life in patients. Early detection of PA is beneficial for avoiding clinical complications of this disease and increasing the quality of life. Noncoding RNAs, including long noncoding RNA, miRNA and circRNA, regulate protein expression, mostly by inhibiting the translation process. Studies have shown that dysregulation of noncoding RNAs is associated with PA. Hence understanding the expression pattern of noncoding RNAs can be considered a promising method for developing biomarkers. This article reviews data on the expression pattern of dysregulated noncoding RNAs involved in PA. Possible molecular mechanisms by which the dysregulated noncoding RNA could possibly induce PA are also described.

Fecal Microbiota Transplantation for Recurrent Clostridioides difficile Infection Associates With Functional Alterations in Circulating microRNAs

BACKGROUND AND AIMS

The molecular mechanisms underlying successful fecal microbiota transplantation (FMT) for recurrent Clostridioides difficile infection (rCDI) remain poorly understood. The primary objective of this study was to characterize alterations in microRNAs (miRs) following FMT for rCDI.

METHODS

Sera from 2 prospective multicenter randomized controlled trials were analyzed for miRNA levels with the use of the Nanostring nCounter platform and quantitative reverse-transcription (RT) polymerase chain reaction (PCR). In addition, rCDI-FMT and toxin-treated animals and ex vivo human colonoids were used to compare intestinal tissue and circulating miRs. miR inflammatory gene targets in colonic epithelial and peripheral blood mononuclear cells were evaluated by quantitative PCR (qPCR) and 3'UTR reporter assays. Colonic epithelial cells were used for mechanistic, cytoskeleton, cell growth, and apoptosis studies.

RESULTS

miRNA profiling revealed up-regulation of 64 circulating miRs 4 and 12 weeks after FMT compared with screening, of which the top 6 were validated in the discovery cohort by means of RT-qPCR. In a murine model of relapsing-CDI, RT-qPCR analyses of sera and cecal RNA extracts demonstrated suppression of these miRs, an effect reversed by FMT. In mouse colon and human colonoids, C difficile toxin B (TcdB) mediated the suppressive effects of CDI on miRs. CDI dysregulated DROSHA, an effect reversed by FMT. Correlation analyses, qPCR ,and 3'UTR reporter assays revealed that miR-23a, miR-150, miR-26b, and miR-28 target directly the 3'UTRs of IL12B, IL18, FGF21, and TNFRSF9, respectively. miR-23a and miR-150 demonstrated cytoprotective effects against TcdB.

CONCLUSIONS

These results provide novel and provocative evidence that modulation of the gut microbiome via FMT induces alterations in circulating and intestinal tissue miRs. These findings contribute to a greater understanding of the molecular mechanisms underlying FMT and identify new potential targets for therapeutic intervention in rCDI.

Reprogramming of microRNA expression via E2F1 downregulation promotes Salmonella infection both in infected and bystander cells

Cells infected with pathogens can contribute to clearing infections by releasing signals that instruct neighbouring cells to mount a pro-inflammatory cytokine response, or by other mechanisms that reduce bystander cells’ susceptibility to infection. Here, we show the opposite effect: epithelial cells infected with Salmonella Typhimurium secrete host factors that facilitate the infection of bystander cells. We find that the endoplasmic reticulum stress response is activated in both infected and bystander cells, and this leads to activation of JNK pathway, downregulation of transcription factor E2F1, and consequent reprogramming of microRNA expression in a time-dependent manner. These changes are not elicited by infection with other bacterial pathogens, such as Shigella flexneri or Listeria monocytogenes. Remarkably, the protein HMGB1 present in the secretome of Salmonella-infected cells is responsible for the activation of the IRE1 branch of the endoplasmic reticulum stress response in non-infected, neighbouring cells. Furthermore, E2F1 downregulation and the associated microRNA alterations promote Salmonella replication within infected cells and prime bystander cells for more efficient infection.

Cells infected with pathogens can release signals that instruct neighbouring cells to mount an immune response or that reduce these cells’ susceptibility to infection. Here, Aguilar et al. show the opposite effect: cells infected with Salmonella Typhimurium secrete host factors that facilitate the infection of bystander cells by activating their ER-stress response.

A novel E2F1-regulated lncRNA, LAPAS1, is required for S phase progression and cell proliferation

The transcription factor E2F1 induces both proliferation and apoptosis and is a critical downstream target of the tumor suppressor RB.

Long non-coding RNAs (lncRNAs) are major regulators of many cellular processes, including cell cycle progression and cell proliferation. However, the mode of action as well as the transcriptional regulation of most lncRNAs are only beginning to be understood.

Here, we report that a novel human lncRNA, LAPAS1, is an E2F1- regulated lncRNA that affects S phase progression. Inhibition of LAPAS1 expression increases percentage of S phase cells, and its silencing in synchronized cells delays their progression through S phase. In agreement with its suggested role in cell cycle progression, prolonged inhibition of LAPAS1 attenuates proliferation of human cancer cells.

Our data demonstrate that LAPAS1 predominantly functions in trans to repress expression of Sphingolipid Transporter 2 (SPNS2). Importantly, knockdown of SPNS2 rescues the effect of LAPAS1 silencing on cell cycle and cell proliferation.

Notably, low levels of LAPAS1 are associated with increased survival of kidney cancer patients.

Summarily, we identify LAPAS1 as a novel E2F-regulated lncRNA that has a potential role in human cancer and regulates cell-cycle progression and cell proliferation, at least in part, via regulation of SPNS2.

The role of HPV-induced epigenetic changes in cervical carcinogenesis (Review)

Cervical cancer is associated with infection by certain types of human papillomaviruses (HPVs), and this affects women worldwide. Despite the improvements in prevention and cure of HPV-induced cervical cancer, it remains the second most common type of cancer in women in the least developed regions of the world. Epigenetic modifications are stable long-term changes that occur in the DNA, and are part of a natural evolutionary process of necessary adaptations to the environment. They do not result in changes in the DNA sequence, but do affect gene expression and genomic stability. Epigenetic changes are important in several biological processes. The effects of the environment on gene expression can contribute to the development of numerous diseases. Epigenetic modifications may serve a critical role in cancer cells, by silencing tumor suppressor genes, activating oncogenes, and exacerbating defects in DNA repair mechanisms. Although cervical cancer is directly related to a persistent high-risk HPV infection, several epigenetic changes have been identified in both the viral DNA and the genome of the infected cells: DNA methylation, histone modification and gene silencing by non-coding RNAs, which initiate and sustain epigenetic changes. In the present review, recent advances in the role of epigenetic changes in cervical cancer are summarized.

Role of miRNAs in cervical cancer: A comprehensive novel approach from pathogenesis to therapy

Human papillomaviruses (HPV) infection is a major causative agent and strongly associated with the development of cervical cancer. Understanding the mechanisms of HPV-induced cervical cancer is extremely useful in therapeutic strategies for primary prevention (HPV vaccines) and secondary prevention (screening and diagnosis of precancerous lesions). However, due to the lack of proper implementation of screening programs in developing countries, cervical cancer is usually diagnosed at advanced stages that result in poor treatment responses. Nearly half of the patients will experience disease recurrence within two years post treatment. Therefore, it is vital to identify new tools for early diagnosis, prognosis, and treatment prediction. MicroRNAs (miRNAs) are small non-coding RNAs, implicated in posttranscriptional regulation of gene expression. Growing evidence has shown that abnormal miRNA expression is associated with cervical cancer progression, metastasis, and influences treatment outcomes. In this review, we provide comprehensive information about miRNA and their potential utility in cervical cancer diagnosis, prognosis, and clinical management to improve patient outcomes.

Epigenetic modulation and understanding of HDAC inhibitors in cancer therapy

The role of genetic and epigenetic factors in tumor initiation and progression is well documented. Histone deacetylases (HDACs), histone methyl transferases (HMTs), and DNA methyl transferases. (DNMTs) are the main proteins that are involved in regulating the chromatin conformation. Among these, histone deacetylases (HDAC) deacetylate the histone and induce gene repression thereby leading to cancer. In contrast, histone acetyl transferases (HATs) that include GCN5, p300/CBP, PCAF, Tip 60 acetylate the histones. HDAC inhibitors are potent drug molecules that can induce acetylation of histones at lysine residues and induce open chromatin conformation at tumor suppressor gene loci and thus resulting in tumor suppression. The key processes regulated by HDAC inhibitors include cell-cycle arrest, chemo-sensitization, apoptosis induction, upregulation of tumor suppressors. Even though FDA approved drugs are confined mainly to haematological malignancies, the research on HDAC inhibitors in glioblastoma multiforme and triple negative breast cancer (TNBC) are providing positive results. Thus, several combinations of HDAC inhibitors along with DNA methyl transferase inhibitors and histone methyl transferase inhibitors are in clinical trials. This review focuses on how HDAC inhibitors regulate the expression of coding and non-coding genes with specific emphasis on their anti-cancer potential.

PKCδ mediates mitochondrial ROS generation and oxidation of HSP60 to relieve RKIP inhibition on MAPK pathway for HCC progression

Both protein kinase C (PKC) and reactive oxygen species (ROS) are well-known signaling messengers cross-talking with each other to activate mitogen-activated protein kinases (MAPKs) for progression of hepatocellular carcinoma (HCC). However, the underlying mechanisms are not well elucidated. Especially, whether mitochondrial ROS (mtROS) is involved and how it triggers MAPK signaling are intriguing. In this study, we found mtROS generation and phosphorylation of MAPKs were mediated by PKCδ in HCCs treated with the tumor promoter 12-O-tetradecanoyl-phorbol-13-acetate (TPA). Heat shock protein 60 (HSP60), one of the chaperones in mitochondria was the major protein oxidized in TPA-treated HCCs. Moreover, depletion of HSP60 or expression of HSP60 cysteine mutant prevented TPA-induced phosphorylation of MAPKs. To delineate how HSP60 mediated MAPK activation, the role of Raf kinase inhibitor protein (RKIP), a negative regulator of MAPK, was investigated. TPA dissociated RKIP from HSP60 in both mitochondria and cytosol, concurrently with translocation of HSP60 and MAPK from mitochondria to cytosol, which was associated with robust phosphorylation of MAPKs in the cytosol. Moreover, TPA induced opposite phenotypical changes of HCCs, G1 cell cycle arrest, and cell migration, which were prevented by mtROS scavengers and depletion of PKCδ and HSP60. Consistently, TPA increased the migration-related genes, hydrogen peroxide inducible clone5, matrix metalloproteinase-1/3, lamininγ2, and suppressed the cell cycle regulator cyclin E1 (CCNE1) via PKCδ/mtROS/HSP60/MAPK-axis. Finally, c-jun and c-fos were required for TPA-induced expression of the migration-related genes and a novel microRNA, miR-6134, was responsible for TPA-induced suppression of CCNE1. In conclusion, PKCδ cross-talked with mtROS to trigger HSP60 oxidation for release of RKIP to activate MAPK, regulating gene expression for migration, and G1 cell cycle arrest in HCC. Targeted therapy aiming at key players like PKCδ, RKIP, and HSP60 is promising for preventing HCC progression.

Regulation of breast cancer metastasis signaling by miRNAs

Despite the decline in death rate from breast cancer and recent advances in targeted therapies and combinations for the treatment of metastatic disease, metastatic breast cancer remains the second leading cause of cancer-associated death in U.S. women. The invasion-metastasis cascade involves a number of steps and multitudes of proteins and signaling molecules. The pathways include invasion, intravasation, circulation, extravasation, infiltration into a distant site to form a metastatic niche, and micrometastasis formation in a new environment. Each of these processes is regulated by changes in gene expression. Noncoding RNAs including microRNAs (miRNAs) are involved in breast cancer tumorigenesis, progression, and metastasis by post-transcriptional regulation of target gene expression. miRNAs can stimulate oncogenesis (oncomiRs), inhibit tumor growth (tumor suppressors or miRsupps), and regulate gene targets in metastasis (metastamiRs). The goal of this review is to summarize some of the key miRNAs that regulate genes and pathways involved in metastatic breast cancer with an emphasis on estrogen receptor α (ERα+) breast cancer. We reviewed the identity, regulation, human breast tumor expression, and reported prognostic significance of miRNAs that have been documented to directly target key genes in pathways, including epithelial-to-mesenchymal transition (EMT) contributing to the metastatic cascade. We critically evaluated the evidence for metastamiRs and their targets and miRNA regulation of metastasis suppressor genes in breast cancer progression and metastasis. It is clear that our understanding of miRNA regulation of targets in metastasis is incomplete.

Computational Analysis of Targeting SARS-CoV-2, Viral Entry Proteins ACE2 and TMPRSS2, and Interferon Genes by Host MicroRNAs

Rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for coronavirus disease 2019 (COVID-19), has led to a global pandemic, failures of local health care systems, and global economic recession. MicroRNAs (miRNAs) have recently emerged as important regulators of viral pathogenesis, particularly among RNA viruses, but the impact of host miRNAs on SARS-CoV-2 infectivity remains unknown. In this study, we utilize the combination of powerful bioinformatic prediction algorithms and miRNA profiling to predict endogenous host miRNAs that may play important roles in regulating SARS-CoV-2 infectivity. We provide a collection of high-probability miRNA binding sites within the SARS-CoV-2 genome as well as within mRNA transcripts of critical viral entry proteins ACE2 and TMPRSS2 and their upstream modulators, the interferons (IFN). By utilizing miRNA profiling datasets of SARS-CoV-2-resistant and -susceptible cell lines, we verify the biological plausibility of the predicted miRNA-target RNA interactions. Finally, we utilize miRNA profiling of SARS-CoV-2-infected cells to identify predicted miRNAs that are differentially regulated in infected cells. In particular, we identify predicted miRNA binders to SARS-CoV-2 ORFs (miR-23a (1ab), miR-29a, -29c (1ab, N), miR-151a, -151b (S), miR-4707-3p (S), miR-298 (5'-UTR), miR-7851-3p (5'-UTR), miR-8075 (5'-UTR)), ACE2 3'-UTR (miR-9-5p, miR-218-5p), TMPRSS2 3'-UTR (let-7d-5p, -7e-5p, miR-494-3p, miR-382-3p, miR-181c-5p), and IFN-α 3'-UTR (miR-361-5p, miR-410-3p). Overall, this study provides insight into potential novel regulatory mechanisms of SARS-CoV-2 by host miRNAs and lays the foundation for future investigation of these miRNAs as potential therapeutic targets or biomarkers.

MicroRNA-Based Fingerprinting of Cervical Lesions and Cancer

The regulatory functions of microRNA (miRNA) are involved in all processes contributing to carcinogenesis and response to viral infections. Cervical cancer in most cases is caused by the persistence of high-risk human papillomavirus (HR-HPV) infection. While oncogenic human papillomaviruses induce aberrant expression of many cellular miRNAs, this dysregulation could be harnessed as a marker in early diagnosis of HR-HPV infection, cervical squamous intraepithelial lesions, and cancer. In recent years, growing data indicate that miRNAs show specific patterns at various stages of cervical pathology. The aim of this review is to systematize current reports on miRNA capacity that can be utilized in personalized diagnostics of cervical precancerous and cancerous lesions. The analysis of the resources available in online databases (National Center for Biotechnology Information—NCBI, PubMed, ScienceDirect, Scopus) was performed. To date, no standardized diagnostic algorithm using the miRNA pattern in cervical pathology has been defined. However, the high sensitivity and specificity of the reported assays gives hope for the development of non-invasive diagnostic tests that take into account the heterogeneity of tumor-related changes. Due to this variability resulting in difficult to predict clinical outcomes, precise molecular tools are needed to improve the diagnostic and therapeutic process.

An increase of microRNA-16-1 is associated with the high proliferation of squamous intraepithelial lesions in the presence of the integrated state of HR-HPV in liquid cytology samples

Studies of cervical cancer (CC) have reported that microRNA-16-1 (miR-16-1), which is an oncomiR, is increased in the tissues and cell lines of CC. The aim of the present study was to investigate the association of miRNA-16-1 expression level with squamous cell carcinoma (SCC), the presence of squamous intraepithelial lesions (SIL) and the integration of high-risk human papillomavirus (HR-HPV) DNA. The current study analyzed 80 samples obtained from women by liquid-based cytology, which revealed that 20 were negative for SIL (NSIL) and without HPV, 20 were low-grade SIL (LSIL), 20 were high-grade SIL (HSIL), and 20 were diagnosed as SCC with HR-HPV. The genotyping of the viral DNA was conducted via an INNO-LiPA-HPV array, the expression of miR-16-1 was determined by reverse transcription-quantitative PCR, and the physical state of the HR-HPV was ascertained by in situ hybridization with amplification with tyramide. A total of eight HR-HPV genotypes were distinguished; the most frequent of these being HPV16, followed by multiple infection with HR-HPV (including HPV16). The mixed state of the HR-HPV was observed in 60 and 65% of LSIL and HSIL cases, respectively, while an integrated HR-HPV state was identified in 90% of cases with SCC. The expression level of miR-16-1 increased according to the grade of SIL, and cases with HSIL exhibited a significantly higher miR-16-1 expression level compared with women with NSIL (P<0.001; Table II). It can therefore be determined that the expression of miR-16-1 effects cellular proliferation, due to the viral integration of various HR-HPV genotypes in unique infection or in multiple infection. Thus, the overexpression of miR-16-1 could be monitored in women with LSIL, in order to discard a major lesion.

Quercetin radiosensitizes non-small cell lung cancer cells through the regulation of miR-16-5p/WEE1 axis

BACKGROUND

Quercetin, a widely distributed bioflavonoid, plays a role in combating diverse human cancers including non-small cell lung cancer (NSCLC). However, the role of quercetin in reversing the radioresistance of NSCLC cells and its underlying mechanism are far from being elucidated.

METHOD

Radiation-resistant NSCLC cell lines were established. Quantitative real-time PCR (qRT-PCR) was used to detect the expression of miR-16-5p and WEE1 G2 checkpoint kinase (WEE1) mRNA in radiation-resistant cells. After being treated with different concentrations of quercetin and different doses of X-ray, cell proliferation and apoptosis were monitored by CCK-8 assay, colony formation assay, and flow cytometry, respectively. Ultimately, the targeting relationship between miR-16-5p and WEE1 was verified via a dual fluorescent reporter gene assay.

RESULTS

The expression of miR-16-5p was down-regulated in radiation-resistant cells, while the expression of WEE1 was up-regulated. Quercetin enhanced the radiosensitivity of NSCLC cells in a dose- and time-dependent manner. Furthermore, quercetin treatment increased the expression of miR-16-5p and decreased the expression of WEE1. The function of quercetin was reversed by miR-16-5p inhibitors or the transfection of WEE1 overexpressing plasmids.

CONCLUSION

In conclusion, quercetin enhanced the radiosensitivity of NSCLC cells via modulating the expression of miR-16-5p and WEE1.

Reciprocal regulation of miR-1205 and E2F1 modulates progression of laryngeal squamous cell carcinoma

The burgeoning functions of many microRNAs (miRs) have been well study in cancer. However, the level and function of miR-1205 in laryngeal squamous cell cancer remains unknown. In the current research, we validated that miR-1205 was notably downregulated in human laryngeal squamous cell carcinoma (LSCC) samples in comparison with tissues adjacent to LSCC, and correlated with T stage, lymph node metastasis, and clinical stage. Using Kaplan–Meier analysis indicates that high expression of miR-1205 has a favorable prognosis for patients with LSCC. Functional assays show that enforced miR-1205 expression attenuates the migration, growth, and invasion of LSCC cells. And E2F1 is verified to be a target of miR-1205, while E2F1 binds to miR-1205 promoter and transcriptionally inhibits miR-1205 expression. Overexpression of E2F1 reverses the inhibitory impacts of miR-1205 on LSCC cells in part. Importantly, E2F1 is abnormally increased in LSCC tissues, and its protein levels were inversely relevant to miR-1205 expression. High E2F1 protein level is in connection with clinical stage, T stage, lymph node metastasis, and poor prognosis. Consequently, reciprocal regulation of miR-1205 and E2F1 plays a crucial role in the progression of LSCC, suggesting a new miR-1205/E2F1-based clinical application for patients of LSCC.

Silencing circular RNA circANKRD36 remits lipopolysaccharide-induced inflammatory damage by regulating microRNA-15/MyD88

Bedsore is a familiar disease, which fearfully harms the health of the patients. We investigated the efficacy and mechanism of circular RNA circANKRD36 on HaCaT cell in inflammatory damage. CCK-8 and flow cytometry were respectively used to investigate the efficacies of lipopolysaccharide (LPS), circANKRD36, and microRNA (miR)-15 on cell viability and apoptosis. Moreover, circANKRD36 and miR-15 expression were changed by cell transfection and investigated by reverse transcription-quantitative polymerase chain reaction. Furthermore, the levels of Bax, pro caspase-3, cleaved caspase-3, interleukin (IL)-1β, IL-6, and proteins of the pathway were investigated by Western blot. Otherwise, the levels of IL-1β and IL-6 were investigated by enzyme-linked immunosorbent assay. Reactive oxygen species (ROS) was investigated by ROS assay. The relation between myeloid differentiation factor 88 (MyD88) and miR-15 was investigated by luciferase assay. LPS caused inflammatory damage and upregulated circANKRD36. circANKRD36 was silenced in cells and si-circANKRD36 remitted inflammatory damage. Furthermore, si-circANKRD36 negatively regulated miR-15 and miR-15 inhibitor could reverse the efficacies of si-circANKRD36. Besides, si-circANKRD36 restrained the NF-κB pathway by upregulating miR-15. Finally, MyD88 was authenticated as a target of miR-15. circANKRD36 remitted cell inflammatory damage upregulating miR-15/MyD88 via the NF-κB pathway in HaCaT cells.

Long noncoding RNA MIAT2 alleviates lipopolysaccharide-induced inflammatory damage in WI-38 cells by sponging microRNA-15

Neonatal pneumonia is a high neonatal mortality disease. We studied the function and mechanism of long noncoding RNA myocardial infarction-associated transcript 2 (lncRNA MIAT2) on lipopolysaccharide (LPS)-induced inflammation in WI-38 cells. Cell Counting Kit-8 and apoptosis assay were respectively used to detect the functions of LPS, MIAT2, and microRNA-15 (miR-15) on viability and apoptosis. MIAT2 and miR-15 expressions were changed by cell transfection. Moreover, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blot, and enzyme-linked immunosorbent assay were used to detect the expressions of interleukin (IL)-6 and monocyte chemoattractant protein-1 (MCP-1). The levels of Bax, cleaved-caspase-3, and cell pathways-related proteins were tested by western blot. Besides, the levels of miR-15 and MIAT2 were tested by RT-qPCR. We found that LPS declined cell viability and heightened apoptosis and levels of Bax, cleaved-caspase-3, IL-6, and MCP-1. MIAT2 was negatively regulated by LPS and it alleviated LPS-induced damage. Furthermore, MIAT2 reversely regulated miR-15 and miR-15 mimic could reverse the effects of MIAT2. Finally, MIAT2 restrained the p38MAPK and NF-κB pathways by downregulating miR-15. In conclusion, MIAT2 alleviated LPS-induced inflammation damage in WI-38 cells by sponging miR-15 via p38MAPK and NF-κB pathways.

MicroRNA Regulation of the Autotaxin-Lysophosphatidic Acid Signaling Axis

The revelation that microRNAs (miRNAs) exist within the human genome uncovered an underappreciated mechanism of gene expression. For cells to regulate expression of their genes, miRNA molecules and argonaute proteins bind to mRNAs and interfere with efficient translation of the RNA transcript. Although miRNAs have important roles in normal tissues, miRNAs may adopt aberrant functions in malignant cells depending on their classification as either a tumor suppressor or oncogenic miRNA. Within this review, the current status of miRNA regulation is described in the context of signaling through the lysophosphatidic acid receptors, including the lysophosphatidic acid-producing enzyme, autotaxin. Thus far, research has revealed miRNAs that increase in response to lysophosphatidic acid stimulation, such as miR-21, miR-30c-2-3p, and miR-122. Other miRNAs inhibit the translation of lysophosphatidic acid receptors, such as miR-15b, miR-23a, and miR200c, or proteins that are downstream of lysophosphatidic acid signaling, such as miR-146 and miR-21. With thousands of miRNAs still uncharacterized, it is anticipated that the complex regulation of lysophosphatidic acid signaling by miRNAs will continue to be elucidated. RNA-based therapeutics have entered the clinic with enormous potential in precision medicine. This exciting field is rapidly emerging and it will be fascinating to witness its expansion in scope.

Regulation of Cyclin E by transcription factors of the naïve pluripotency network in mouse embryonic stem cells

Continuous, non-cell cycle-dependent expression of cyclin E is a characteristic feature of mouse embryonic stem cells (mESCs). We studied the 5′ regulatory region of Cyclin E, also known as Ccne1, and identified binding sites for transcription factors of the naïve pluripotency network, including Esrrb, Klf4, and Tfcp2l1 within 1 kilobase upstream of the transcription start site. Luciferase assay and chromatin immunoprecipitation-quantitative polymerase chain reaction (ChiP–qPCR) study highlighted one binding site for Esrrb that is essential to transcriptional activity of the promoter region, and three binding sites for Klf4 and Tfcp2l1. Knockdown of Esrrb, Klf4, and Tfcp2l1 reduced Cyclin E expression whereas overexpression of Esrrb and Klf4 increased it, indicating a strong correlation between the expression level of these factors and that of cyclin E. We observed that cyclin E overexpression delays differentiation induced by Esrrb depletion, suggesting that cyclin E is an important target of Esrrb for differentiation blockade. We observed that mESCs express a low level of miR-15a and that transfection of a miR-15a mimic decreases Cyclin E mRNA level. These results lead to the conclusion that the high expression level of Cyclin E in mESCs can be attributed to transcriptional activation by Esrrb as well as to the absence of its negative regulator, miR-15a.

MicroRNA regulation of CD8+ T cell responses

MicroRNAs (miRNAs) are a class of short noncoding RNAs that play critical roles in the regulation of a broad range of biological processes. Like transcription factors, miRNAs exert their effects by modulating the expression of networks of genes that operate in common or convergent pathways. CD8⁺ T cells are critical agents of the adaptive immune system that provide protection from infection and cancer. Here, we review the important roles of miRNAs in the regulation of CD8⁺ T cell biology and provide perspectives on the broader emerging principles of miRNA function.

MTMR3 is upregulated in patients with breast cancer and regulates proliferation, cell cycle progression and autophagy in breast cancer cells

As a member of the myotubularin family, myotubularin related protein 3 (MTMR3) has been demonstrated to participate in tumor development, including oral and colon cancer. However, little is known about its functional roles in breast cancer. In the present study, the expression of MTMR3 in breast cancer was evaluated by immunohistochemical staining of tumor tissues from 172 patients. Online data was then used for survival analysis from the PROGgeneV2 database. In vitro, MTMR3 expression was silenced in MDA-MB-231 cells via lentiviral shRNA transduction. MTT, colony formation and flow cytometry assays were performed in the control and MTMR3-silenced cells to evaluate the cell growth, proliferation and cell cycle phase distribution, respectively. Western blotting was used to evaluate the protein expression levels of autophagy-related markers. The results demonstrated that the expression of MTMR3 in breast cancer tissues was significantly increased compared with adjacent normal tissues. MTMR3 was highly expressed in triple-negative breast cancer and was associated with disease recurrence. MTMR3 knockdown in MDA-MB-231 cells inhibited cell proliferation and induced cell cycle arrest and autophagy. The present results indicated that MTMR3 may have an important role in promoting the progression of breast cancer, and its inhibition may serve as a promising therapeutic target for breast cancer treatment.

MicroRNA-15a Regulates the Differentiation of Intramuscular Preadipocytes by Targeting ACAA1, ACOX1 and SCP2 in Chickens

Our previous studies showed that microRNA-15a (miR-15a) was closely related to intramuscular fat (IMF) deposition in chickens; however, its regulatory mechanism remains unclear. Here, we evaluated the expression characteristics of miR-15a and its relationship with the expression of acetyl-CoA acyltransferase 1 (ACAA1), acyl-CoA oxidase 1 (ACOX1) and sterol carrier protein 2 (SCP2) by qPCR analysis in Gushi chicken breast muscle at 6, 14, 22, and 30 weeks old, where we performed transfection tests of miR-15a mimics in intramuscular preadipocytes and verified the target gene of miR-15a in chicken fibroblasts (DF1). The miR-15a expression level at 30 weeks increased 13.5, 4.5, and 2.7-fold compared with the expression levels at 6, 14, and 22 weeks, respectively. After 6 days of induction, miR-15a over-expression significantly promoted intramuscular adipogenic differentiation and increased cholesterol and triglyceride accumulation in adipocytes. Meanwhile, 48 h after transfection with miR-15a mimics, the expression levels of ACAA1, ACOX1 and SCP2 genes decreased by 56.52%, 31.18% and 37.14% at the mRNA level in intramuscular preadipocytes. In addition, the co-transfection of miR-15a mimics and ACAA1, ACOX1 and SCP2 3′UTR (untranslated region) dual-luciferase vector significantly inhibited dual-luciferase activity in DF1 cells. Taken together, our data demonstrate that miR-15a can reduce fatty acid oxidation by targeting ACAA1, ACOX1, and SCP2, which subsequently indirectly promotes the differentiation of chicken intramuscular preadipocytes.

Small extracellular vesicles and their miRNA cargo are anti-apoptotic members of the senescence-associated secretory phenotype

Loss of functionality during aging of cells and organisms is caused and accompanied by altered cell-to-cell communication and signalling. One factor thereby is the chronic accumulation of senescent cells and the concomitant senescence-associated secretory phenotype (SASP) that contributes to microenvironment remodelling and a pro-inflammatory status. While protein based SASP factors have been well characterized, little is known about small extracellular vesicles (sEVs) and their miRNA cargo. Therefore, we analysed secretion of sEVs from senescent human dermal fibroblasts and catalogued the therein contained miRNAs. We observed a four-fold increase of sEVs, with a concomitant increase of >80% of all cargo miRNAs. The most abundantly secreted miRNAs were predicted to collectively target mRNAs of pro-apoptotic proteins, and indeed, senescent cell derived sEVs exerted anti-apoptotic activity. In addition, we identified senescence-specific differences in miRNA composition of sEVs, with an increase of miR-23a-5p and miR-137 and a decrease of miR-625-3p, miR-766-3p, miR-199b-5p, miR-381-3p, miR-17-3p. By correlating intracellular and sEV-miRNAs, we identified miRNAs selectively retained in senescent cells (miR-21-3p and miR-17-3p) or packaged specifically into senescent cell derived sEVs (miR-15b-5p and miR-30a-3p). Therefore, we suggest sEVs and their miRNA cargo to be novel, members of the SASP that are selectively secreted or retained in cellular senescence.

The Role of Non-Coding RNAs Involved in Nickel-Induced Lung Carcinogenic Mechanisms

Nickel is a naturally occurring element found in the Earth’s crust and an International Agency for Research on Cancer (IARC)-classified human carcinogen. While low levels found in the natural environment pose a minor concern, the extensive use of nickel in industrial settings such as in the production of stainless steel and various alloys complicate human exposure and health effects. Notably, interactions with nickel macromolecules, primarily through inhalation, have been demonstrated to promote lung cancer. Mechanisms of nickel-carcinogenesis range from oxidative stress, DNA damage, and hypoxia-inducible pathways to epigenetic mechanisms. Recently, non-coding RNAs have drawn increased attention in cancer mechanistic studies. Specifically, nickel has been found to disrupt expression and functions of micro-RNAs and long-non-coding RNAs, resulting in subsequent changes in target gene expression levels, some of which include key cancer genes such as p53, MDM2, c-myc, and AP-1. Non-coding RNAs are also involved in well-studied mechanisms of nickel-induced lung carcinogenesis, such as the hypoxia-inducible factor (HIF) pathway, oxidative stress, DNA damage and repair, DNA hypermethylation, and alterations in tumor suppressors and oncogenes. This review provides a summary of the currently known epigenetic mechanisms involved in nickel-induced lung carcinogenesis, with a particular focus on non-coding RNAs.

Tumour biomarkers-Tracing the molecular function and clinical implication

In recent years, with the increase in cancer mortality caused by metastasis, and with the development of individualized and precise medical treatment, early diagnosis with precision becomes the key to decrease the death rate. Since detecting tumour biomarkers in body fluids is the most non‐invasive way to identify the status of tumour development, it has been widely investigated for the usage in clinic. These biomarkers include different expression or mutation in microRNAs (miRNAs), circulating tumour DNAs (ctDNAs), proteins, exosomes and circulating tumour cells (CTCs). In the present article, we summarized and discussed some updated research on these biomarkers. We overviewed their biological functions and evaluated their multiple roles in human and small animal clinical treatment, including diagnosis of cancers, classification of cancers, prognostic and predictive values for therapy response, monitors for therapy efficacy, and anti‐cancer therapeutics. Biomarkers including different expression or mutation in miRNAs, ctDNAs, proteins, exosomes and CTCs provide more choice for early diagnosis of tumour detection at early stage before metastasis. Combination detection of these tumour biomarkers may provide higher accuracy at the lowest molecule combination number for tumour early detection. Moreover, tumour biomarkers can provide valuable suggestions for clinical anti‐cancer treatment and execute monitoring of treatment efficiency.

Peripheral blood E2F1 mRNA in depression and following electroconvulsive therapy

The E2F transcription factors are a group of proteins that bind to the promotor region of the adenovirus E2 gene. E2F1, the first family member to be cloned, is linked to functions including cell proliferation and apoptosis, DNA repair, cell senescence and metabolism. We recently performed a deep sequencing study of micro-RNA changes in whole blood following ECT. Two micro-RNAs (miR-126-3p and miR-106a-5p) were identified and gene targeting analysis identified E2F1 as a shared target of these miRNAs. To our knowledge, no studies have examined E2F1 mRNA levels in patients with depression. Peripheral blood E2F1 mRNA levels were therefore examined in patients with depression, compared to healthy controls, and the effects of a course of ECT on peripheral blood E2F1 mRNA was investigated. Depressed patient and healthy control groups were balanced on the basis of age and sex. E2F1 mRNA levels were significantly lower in depressed patients in comparison to controls (p = .009) but did not change with ECT. There was no relationship between baseline E2F1 levels and depression severity, response to treatment, presence of psychosis or polarity of depression. There were no significant correlations between E2F1 levels and mood scores based on the HAM-D24. These results indicate that reduced peripheral blood E2F1 mRNA could be a trait feature of depression.

High Glucose-Induced Apoptosis in Human Kidney Cells Was Alleviated by miR-15b-5p Mimics

MicroRNAs were involved in a wide range of biological processes of diabetic nephropathy (DN). It is reported that miR-15b-5p was downregulated in the patients with DN. However, the mechanisms underlying the regulatory effects of miR-15b-5p on patients with diabetes remain unclear. Thus, this study aimed to investigate the role of miR-15b-5p during high glucose (HG)-induced apoptosis in human kidney cells. Quantitative real-time (qRT)-PCR was used to detect the level of miR-15b-5p. CCK-8 assay, EdU staining assays and flow cytometry were used to detect cell proliferation, apoptosis respectively in vitro. In addition, Western blotting was used to determine active caspase-3, cleaved poly(ADP-ribose) polymerase (PARP), phosphorylated (p)-AKT, p-mammalian target of rapamycin (mTOR), p-S6, p-c-Jun N terminal kinase (JNK), p-p38 and p-extracellular signal-regulated kinase (ERK) proteins levels. The expression of miR-15b-5p in patients with DN were dramatically decreased compared with health persons. Similarly, HG down-regulated the expression of miR-15b-5p in HK-2 cells. In contrast, miR-15b-5p mimics alleviated HG-induced apoptosis in HK-2 cells via decreasing the expressions of active caspase 3 and cleaved PARP. EdU detection further confirmed that miR-15b-5p mimics attenuated the anti-proliferation effect of HG in HK-2 cells. Furthermore, HG-induced Akt/mTOR pathway downregulation and JNK upregulation were markedly reversed by miR-15b-5p mimics in cells. The data suggested that miR-15b-5p mimics protects HK-2 cells from HG-induced apoptosis. The anti-apoptotic effects of miR-15b-5p may due to the activation of the Akt/mTOR pathway as well as inactivation of JNK. Taken together, miR-15b-5p might be a potential therapeutic target for the treatment of patients with DN.

Extensive reprogramming of the nascent transcriptome during iPSC to hepatocyte differentiation

Hepatocyte-like cells (HLCs) derived from induced pluripotent stem cells (iPSCs) provide a renewable source of cells for drug discovery, disease modelling and cell-based therapies. Here, by using GRO-Seq we provide the first genome-wide analysis of the nascent RNAs in iPSCs, HLCs and primary hepatocytes to extend our understanding of the transcriptional changes occurring during hepatic differentiation process. We demonstrate that a large fraction of hepatocyte-specific genes are regulated at transcriptional level and identify hundreds of differentially expressed non-coding RNAs (ncRNAs), including primary miRNAs (pri-miRNAs) and long non-coding RNAs (lncRNAs). Differentiation induced alternative transcription start site (TSS) usage between the cell types as evidenced for miR-221/222 and miR-3613/15a/16-1 clusters. We demonstrate that lncRNAs and coding genes are tightly co-expressed and could thus be co-regulated. Finally, we identified sets of transcriptional regulators that might drive transcriptional changes during hepatocyte differentiation. These included RARG, E2F1, SP1 and FOXH1, which were associated with the down-regulated transcripts, and hepatocyte-specific TFs such as FOXA1, FOXA2, HNF1B, HNF4A and CEBPA, as well as RXR, PPAR, AP-1, JUNB, JUND and BATF, which were associated with up-regulated transcripts. In summary, this study clarifies the role of regulatory ncRNAs and TFs in differentiation of HLCs from iPSCs.

Upregulated gga-miR-16-5p Inhibits the Proliferation Cycle and Promotes the Apoptosis of MG-Infected DF-1 Cells by Repressing PIK3R1-Mediated the PI3K/Akt/NF-κB Pathway to Exert Anti-Inflammatory Effect

Mycoplasma gallisepticum (MG) mainly infects chickens to initiate chronic respiratory disease (CRD). microRNAs (miRNAs) play vital roles according to previously reported studies. Our previous study showed that gga-miR-16-5p, in MG-infected lungs of chicken embryo, was upregulated by Illumina sequencing. The study aimed to reveal what role gga-miR-16-5p plays in CRD progression. gga-miR-16-5p was upregulated in MG-infected fibroblast cells (DF-1). Phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1) was demonstrated as the target gene of gga-miR-16-5p. Furthermore, PIK3R1 expression was lower in MG-infected groups than it in noninfected controls measured by qPCR. Additionally, overexpressed gga-miR-16-5p could downregulate PIK3R1 and phosphorylated serine/threonine kinase (p-Akt) to express protein, whereas there is an opposite effect on inhibition. Overexpressed gga-miR-16-5p resulted in decreased activity of tumor necrosis factor alpha (TNF-α) and the nuclear factor-kappaB (NF-κB) by qPCR. Furthermore, overexpressed gga-miR-16-5p restricted cell multiplication, cycle progression, and increased apoptosis of MG-infected DF-1 cells, whereas inhibited gga-miR-16-5p led to the opposite effect. Collectively, upregulated gga-miR-16-5p could decrease multiplication, cycle progression, and increase apoptosis of MG-infected DF-1 cells, at least partly through directly targeting PIK3R1 and inhibiting PI3K/Akt/NF-κB pathway to exert an anti-inflammatory effect. Our results will provide more experimental evidence to bring pathogenesis of MG infection to light.

MiR-15b and miR-322 inhibit SETD3 expression to repress muscle cell differentiation

SETD3 is a member of SET-domain containing methyltransferase family, which plays critical roles in various biological events. It has been shown that SETD3 could regulate the transcription of myogenic regulatory genes in C2C12 differentiation and promote myoblast determination. However, how SETD3 is regulated during myoblast differentiation is still unknown. Here, we report that two important microRNAs (miRNAs) could repress SETD3 and negatively contribute to myoblast differentiation. Using microRNA (miRNA) prediction engines, we identify and characterize miR-15b and miR-322 as the primary miRNAs that repress the expression of SETD3 through directly targeting the 3’-untranslated region of SETD3 gene. Functionally, overexpression of miR-15b or miR-322 leads to the repression of endogenous SETD3 expression and the inhibition of myoblast differentiation, whereas inhibition of miR-15b or miR-322 derepresses endogenous SETD3 expression and facilitates myoblast differentiation. In addition, knockdown SETD3 in miR-15b or miR-322 repressed myoblasts is able to rescue the facilitated differentiation phenotype. More interestingly, we revealed that transcription factor E2F1 or FAM3B positively or negatively regulates miR-15b or miR-322 expression, respectively, during muscle cell differentiation, which in turn affects SETD3 expression. Therefore, our results establish two parallel cascade regulatory pathways, in which transcription factors regulate microRNAs fates, thereby controlling SETD3 expression and eventually determining skeletal muscle differentiation.

FBXW7 mutations reduce binding of NOTCH1, leading to cleaved NOTCH1 accumulation and target gene activation in CLL

NOTCH1 is mutated in 10% of chronic lymphocytic leukemia (CLL) patients and is associated with poor outcome. However, NOTCH1 activation is identified in approximately one-half of CLL cases even in the absence of NOTCH1 mutations. Hence, there appear to be additional factors responsible for the impairment of NOTCH1 degradation. E3-ubiquitin ligase F-box and WD40 repeat domain containing-7 (FBXW7), a negative regulator of NOTCH1, is mutated in 2% to 6% of CLL patients. The functional consequences of these mutations in CLL are unknown. We found heterozygous FBXW7 mutations in 36 of 905 (4%) untreated CLL patients. The majority were missense mutations (78%) that mostly affected the WD40 substrate binding domain; 10% of mutations occurred in the first exon of the α-isoform. To identify target proteins of FBXW7 in CLL, we truncated the WD40 domain in CLL cell line HG-3 via clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein-9 (Cas9). Homozygous truncation of FBXW7 resulted in an increase of activated NOTCH1 intracellular domain (NICD) and c-MYC protein levels as well as elevated hypoxia-inducible factor 1-α activity. In silico modeling predicted that novel mutations G423V and W425C in the FBXW7-WD40 domain change the binding of protein substrates. This differential binding was confirmed via coimmunoprecipitation of overexpressed FBXW7 and NOTCH1. In primary CLL cells harboring FBXW7 mutations, activated NICD levels were increased and remained stable upon translation inhibition. FBXW7 mutations coincided with an increase in NOTCH1 target gene expression and explain a proportion of patients characterized by dysregulated NOTCH1 signaling.

Role of miRNAs in lung cancer

Lung cancer (LC) is the leading cause of cancer-related deaths all over the world, among both men and women, with an incidence of over 200,000 new cases per year coupled with a very high mortality rate. LC comprises of two major clinicopathological categories: small-cell (SCLC) and nonsmall-cell lung carcinoma (NSCLC). The microRNAs (miRNAs) are small noncoding RNAs, usually 18-25 nucleotides long, which repress protein translation through binding to complementary target mRNAs. The miRNAs regulate many biological processes including cell cycle regulation, cellular growth, proliferation, differentiation, apoptosis, metabolism, neuronal patterning, and aging. This review summarizes the role of miRNAs expression in LC. It also provides information about the miRNAs as biomarker and therapeutic target for lung cancer. Understanding the role of miRNAs in LC may provide insights into the diagnosis and treatment strategy for LC.

Omega-3 fatty acid DHA modulates p53, survivin, and microRNA-16-1 expression in KRAS-mutant colorectal cancer stem-like cells

Background

The presence of chemotherapy-resistant colorectal cancer stem cells (CCSCs) with KRAS mutation is thought to be one of the primary causes for treatment failure in colorectal cancer (CRC). P53, survivin, and microRNA-16-1 are challenging targets for anticancer drugs which are associated with chemoresistance in CRC. Yet, no p53-, survivin-, and microRNA-16-1-modulating drug with low toxicity but high efficacy against KRAS-mutant CCSCs have been approved for clinical application in CRC. Here, we investigated whether in vitro concentrations of DHA equal to human plasma levels, are able to modulate, Wt-p53, survivin, and microRNA-16-1 in CRC cells with stem cell-like properties.

Methods

Wt-p53/KRAS-mutant CRC cells (HCT-116) with stem cell-like properties were treated with 100-, 150- and 200-μM/L DHA, after which cell number, viability, growth inhibition, Wt-p53, survivin and microRNA-16-1 expression, caspase-3 activation and apoptotic-rate were evaluated by different cellular and molecular techniques.

Results

After 24-, 48-, and 72-h treatments with 100- to 200-μM/L DHA, growth inhibition- rates were measured to be 54.7% to 59.7%, 73.% to 75.8%, and 63.3% to 97.7%, respectively. Treatment for 48 h with indicated DHA concentrations decreased cell number and viability. In addition, we observed a decrease in both the transcript and protein levels of survivin followed by 1.3- to 1.7- and 1.1- to 4.7-fold increases in the Wt-p53 accumulation and caspase-3 activation levels respectively. Treatment with 100 and 150 μM/L DHA increased microRNA-16-1 expression levels by 1.3- to 1.7-fold and enhanced the microRNA-16-1/survivin mRNA, p53/survivin, and caspase-3/survivin protein ratios by 1.7- to 1.8-, 1.3- to 2.6-, and 1.3- to 2-fold increases respectively. A decrease in the number of live cells and an increase in the number of apoptotic cells were also observed with increasing DHA concentrations.

Conclusion

Wt-p53, survivin, and microRNA-16-1 appear to be promising molecular targets of DHA. Thus, DHA might represent an attractive anti-tumor agent directed against KRAS-mutant CCSCs.

EIF2S3Y suppresses the pluripotency state and promotes the proliferation of mouse embryonic stem cells

Eukaryotic translation initiation factor 2, subunit 3, and structural gene Y-linked (EIF2S3Y) is essential for spermatogenesis in mouse models. However, its effect on embryonic stem (ES) cells remains unknown. In our observation, differentiated ES cells showed higher levels of EIF2S3Y. To further elucidate its role in ES cells, we utilized ES-derived EIF2S3Y-overexpressing cells and found that EIF2S3Y down-regulated the pluripotency state of ES cells, which might be explained by decreased histone methylation levels because of reduced levels of ten-eleven translocation 1 (TET1). Moreover, EIF2S3Y-overexpressing cells showed an enhanced proliferation rate, which might be due to increased Cyclin A and Cyclin E levels. This study highlighted novel roles of EIF2S3Y in the pluripotency maintenance and proliferation control of ES cells, which would provide an efficient model to study germ cell generation as well as cancer development using ES cells, thus providing valuable target for clinical applications of ES cells.

MiR-16-5p mediates a positive feedback loop in EV71-induced apoptosis and suppresses virus replication

Enterovirus 71 (EV71) is the predominant causative pathogen of hand-foot-and-mouth disease (HFMD). Contrary to other HFMD-causing enterovirus, EV71 can lead to severe neurological complications, even death. MicroRNAs (miRNAs) are small non-coding RNAs that constitute the largest family of gene regulators participating in numerous biological or pathological processes. We previously reported that miR-16-5p increases with severity of HFMD by investigating the expression patterns of host miRNAs in patients with HFMD. However, the mechanisms by which EV71 induces miR-16-5p expression are not clear, and the interaction between EV71 and miR-16-5p is not yet fully understood. Here, we confirmed EV71-induced expression of miR-16-5p both in vitro and in vivo and show that upregulation of miR-16-5p by EV71 infection may occur at the posttranscriptional level. Moreover, EV71-induced caspase activation facilitates the processing of pri-miR-16-1. We also revealed that miR-16-5p can promote EV71-induced nerve cells apoptosis through activating caspase-3. In addition, we found that miR-16-5p can inhibit EV71 replication. CCNE1 and CCND1, two important cell cycle regulators, play an important role in the suppression of EV71 replication by miR-16-5p. Therefore, miR-16-5p is a positive feedback regulator in EV71-induced apoptosis and a suppressor of virus replication. These results help in understanding the interaction network between miRNA and EV71 infection and provide a potential target for the development of antiviral therapy.

microRNAs and Acute Myeloid Leukemia Chemoresistance: A Mechanistic Overview

Up until the early 2000s, a functional role for microRNAs (miRNAs) was yet to be elucidated. With the advent of increasingly high-throughput and precise RNA-sequencing techniques within the last two decades, it has become well established that miRNAs can regulate almost all cellular processes through their ability to post-transcriptionally regulate a majority of protein-coding genes and countless other non-coding genes. In cancer, miRNAs have been demonstrated to play critical roles by modifying or controlling all major hallmarks including cell division, self-renewal, invasion, and DNA damage among others. Before the introduction of anthracyclines and cytarabine in the 1960s, acute myeloid leukemia (AML) was considered a fatal disease. In decades since, prognosis has improved substantially; however, long-term survival with AML remains poor. Resistance to chemotherapy, whether it is present at diagnosis or induced during treatment is a major therapeutic challenge in the treatment of this disease. Certain mechanisms such as DNA damage response and drug targeting, cell cycling, cell death, and drug trafficking pathways have been shown to be further dysregulated in treatment resistant cancers. miRNAs playing key roles in the emergence of these drug resistance phenotypes have recently emerged and replacement or inhibition of these miRNAs may be a viable treatment option. Herein, we describe the roles miRNAs can play in drug resistant AML and we describe miRNA-transcript interactions found within other cancer states which may be present within drug resistant AML. We describe the mechanisms of action of these miRNAs and how they can contribute to a poor overall survival and outcome as well. With the precision of miRNA mimic- or antagomir-based therapies, miRNAs provide an avenue for exquisite targeting in the therapy of drug resistant cancers.

Epigenetic regulation of miR-200 as the potential strategy for the therapy against triple-negative breast cancer

MicroRNAs (miRNAs) are a class of small, non-coding RNAs that are involved in the regulation of gene expression at the post-transcriptional level. MicroRNAs play an important role in cancer cell proliferation, survival and apoptosis. Epigenetic modifiers regulate the microRNA expression. Among the epigenetic players, histone deacetylases (HDACs) function as the key regulators of microRNA expression. Epigenetic machineries such as DNA and histone modifying enzymes and various microRNAs have been identified as the important contributors in cancer initiation and progression. Recent studies have shown that developing innovative microRNA-targeting therapies might improve the human health, specifically against the disease areas of high unmet medical need. Thus microRNA based therapeutics are gaining importance for anti-cancer therapy. Studies on Triple negative breast cancer (TNBC) have revealed the early relapse and poor overall survival of patients which needs immediate therapeutic attention. In this report, we focus the effect of HDAC inhibitors on TNBC cell proliferation, regulation of microRNA gene expression by a series of HDAC genes, chromatin epigenetics, epigenetic remodelling at miR-200 promoter and its modulation by various HDACs. We also discuss the need for identifying novel HDAC inhibitors for modulation of miR-200 in triple negative breast cancer.

A novel lncRNA, GASL1, inhibits cell proliferation and restricts E2F1 activity

The human genome encodes thousands of unique long non-coding RNAs (lncRNAs), many of which are emerging as critical regulators of cell fate. However, their functions as well as their transcriptional regulation are only partially understood. The E2F1 transcription factor induces both proliferation and apoptosis, and is a critical downstream target of the tumor suppressor, RB. Here, we provide evidence that a novel lncRNA named GASL1 is transcriptionally regulated by E2F1; GASL1 levels are elevated upon activation of exogenous E2F1 or endogenous E2Fs. Inhibition of GASL1 expression induced cell cycle progression, and in particular, G1 exit. Moreover, GASL1 silencing enhanced cell proliferation, while, conversely, its ectopic expression inhibited proliferation. Knockdown of GASL1 also enhanced E2F1-induced apoptosis, suggesting the existence of an E2F/GASL1 negative feedback loop. In agreement with this notion, silencing of GASL1 led to increased levels of phosphorylated pRB and loss of Rb impaired the effect of GASL1 silencing on G1 exit. Importantly, xenograft experiments demonstrated that GASL1 deletion enhances tumor growth. Moreover, low levels of GASL1 are associated with decreased survival of liver cancer patients. Taken together, our data identify GASL1 as a novel lncRNA regulator of cell cycle progression and cell proliferation with a potential role in cancer.