Signaling-mediated regulation of MicroRNA processing

MicroRNA in prostate cancer: from biogenesis to applicative potential

Prostate cancer is the most common solid malignant tumor in men, characterized by high morbidity and mortality. While current screening tools, such as prostate-specific antigen (PSA) testing and digital rectal examination, are available for early detection of prostate cancer, their sensitivity and specificity are limited. Tissue puncture biopsy, although capable of offering a definitive diagnosis, has poor positive predictive rates and burdens the patient more. Therefore, more reliable molecular diagnostic tools for prostate cancer urgently need to be developed. In recent years, microRNAs (miRNAs) have attracted much attention in prostate cancer research. miRNAs are extensively engaged in biological processes such as cell proliferation, differentiation, apoptosis, migration, and invasion by modulating gene expression post-transcriptionally. Dysregulation of miRNA expression in cancer is considered a critical factor in tumorigenesis and progression. This review first briefly introduces the biogenesis of miRNAs and their functions in cancer, then focuses on tumor-promoting miRNAs and tumor-suppressor miRNAs in prostate cancer. Finally, the potential application of miRNAs as multifunctional tools for cancer diagnosis, prognostic assessment, and therapy is discussed in detail. The concluding section summarizes the major points of the review and the challenges ahead.

Unveiling the Role of Exosomes in the Pathophysiology of Sepsis: Insights into Organ Dysfunction and Potential Biomarkers

Extracellular vesicles (EVs) are tools for intercellular communication, mediating molecular transport processes. Emerging studies have revealed that EVs are significantly involved in immune processes, including sepsis. Sepsis, a dysregulated immune response to infection, triggers systemic inflammation and multi-organ dysfunction, posing a life-threatening condition. Although extensive research has been conducted on animals, the complex inflammatory mechanisms that cause sepsis-induced organ failure in humans are still not fully understood. Recent studies have focused on secreted exosomes, which are small extracellular vesicles from various body cells, and have shed light on their involvement in the pathophysiology of sepsis. During sepsis, exosomes undergo changes in content, concentration, and function, which significantly affect the metabolism of endothelia, cardiovascular functions, and coagulation. Investigating the role of exosome content in the pathogenesis of sepsis shows promise for understanding the molecular basis of human sepsis. This review explores the contributions of activated immune cells and diverse body cells' secreted exosomes to vital organ dysfunction in sepsis, providing insights into potential molecular biomarkers for predicting organ failure in septic shock.

Mechanism of Circ_HECW2 regulating osteoblast apoptosis in osteoporosis by attenuating the maturation of miR-1224-5p

BACKGROUND

Osteoporosis (OP) poses a significant clinical challenge with escalating morbidity. This study explores Circ_HECW2 expression in OP patients and its regulatory role in lipopolysaccharide (LPS)-induced osteoblast apoptosis.

METHODS

Circ_HECW2 expression in OP patient serum and healthy controls was quantified using RT-qPCR. Diagnostic value of Circ_HECW2 for OP was assessed via ROC curve. Pearson's correlation model examined associations between indicators. Human osteoblasts HFOB1.19, treated with LPS, were analyzed for Circ_HECW2, pre-miR-1224, miR-1224-5p, and PDK2 mRNA levels. TUNEL assay determined cell apoptosis and Western blot assessed cleaved-caspase-3 protein levels. RNase R resistance assay and actinomycin D assay confirmed Circ_HECW2's cyclic structure. RNA pull-down and dual-luciferase reporter assay verified binding relationships between Circ_HECW2 and miR-1224 and between miR-1224-5p and PDK2.

RESULTS

Circ_HECW2 exhibited elevated expression in OP patients with diagnostic significance and a negative correlation with lumbar T-score. LPS co-culture increased Circ_HECW2 expression in HFOB1.19 cells, significantly elevating apoptosis index and cleaved-caspase-3. Circ_HECW2 downregulation inhibited HFOB1.19 apoptosis, reduced pre-miR-1224 expression, and elevated mature miR-1224-5p. Circ_HECW2 bound to pre-miR-1224, and inhibiting miR-1224-5p reversed the effect of Circ_HECW2 downregulation on osteoblast apoptosis. miR-1224-5p targeted PDK2 transcription.

CONCLUSION

Circ_HECW2, highly expressed in OP, holds diagnostic significance and reflects disease severity. Circ_HECW2 reduces mature miR-1224-5p by binding to pre-miR-1224, upregulating PDK2, and facilitating LPS-induced osteoblast apoptosis.

The role of miRNAs in laryngeal cancer pathogenesis and therapeutic resistance - A focus on signaling pathways interplay

Laryngeal cancer (LC)is the malignancy of the larynx (voice box). The majority of LC are squamous cell carcinomas. Many risk factors were reported to be associated with LC as tobacco use, obesity, alcohol intake, human papillomavirus (HPV) infection, and asbestos exposure. Besides, epigenetics as non-coding nucleic acids also have a great role in LC. miRNAs are short nucleic acid molecules that can modulate multiple cellular processes by regulating the expression of their genes. Therefore, LC progression, apoptosis evasions, initiation, EMT, and angiogenesis are associated with dysregulated miRNA expressions. miRNAs also could have some vital signaling pathways such as mTOR/P-gp, Wnt/-catenin signaling, JAK/STAT, KRAS, and EGF. Besides, miRNAs also have a role in the modulation of LC response to different therapeutic modalities. In this review, we have provided a comprehensive and updated overview highlighting the microRNAs biogenesis, general biological functions, regulatory mechanisms, and signaling dysfunction in LC carcinogenesis, in addition to their clinical potential for LC diagnosis, prognosis, and chemotherapeutics response implications.

LncRNA NEAT1 promotes malignant phenotypes and TMZ resistance in glioblastoma stem cells by regulating let-7g-5p/MAP3K1 axis

Glioblastoma multiforme (GBM) is one of the most malign brain tumors in adults. Temozolomide (TMZ) is an oral chemotherapy drug constituting the backbone of chemotherapy regimens utilized as first-line treatment of GBM. However, resistance to TMZ often leads to treatment failure. In the present study, we explored the expression and related mechanisms of nuclear enriched abundant transcript 1 (NEAT1) in glioma stem cells (GSCs). Quantitative real-time PCR (qRT-PCR) showed that NEAT1 was up-regulated in serum samples of GBM patients and GSCs isolated from U87, U251 cell lines. Functional experiments showed that NEAT1 knockdown restrained malignant behaviors of GSC, including proliferation, migration and invasion. Dual-luciferase assays identified let-7g-5p was a downstream target and negatively adjusted by NEAT1. Restoration of let-7g-5p impeded tumor progression by inhibiting proliferation, migration and invasion. Mitogen-activated protein kinase kinase kinase 1 (MAP3K1), as a direct target of let-7g-5p, was positively regulated by NEAT1 and involved to affect the regulation of NEAT1 on GSCs' behaviors. In conclusion, our results suggested that NEAT1 promoted GSCs progression via NEAT1/let-7g-5p/MAP3K1 axis, which provided a depth insight into TMZ resistance mechanism.

Current paradigms in epigenetic anticancer therapeutics and future challenges

Any alteration at the genetic or epigenetic level, may result in multiplex of diseases including tumorigenesis which ultimately results in the cancer development. Restoration of the normal epigenome by reversing the epigenetic alterations have been reported in tumors paving the way for development of an effective epigenetic treatment in cancer. However, delineating various epigenetic events has been a challenging task so far despite substantial progress in understanding DNA methylation and histone modifications during transcription of genes. Many inhibitors in the form of epigenetic drugs mostly targeting chromatin and histone modifying enzymes including DNA methyltransferase (DNMT) enzyme inhibitors and a histone deacetylases (HDACs) inhibitor, have been in use subsequent to the approval by FDA for cancer treatment. Similarly, other inhibitory drugs, such as FK228, suberoylanilide hydroxamic acid (SAHA) and MS-275, have been successfully tested in clinical studies. Despite all these advancements, still we see a hazy view as far as a promising epigenetic anticancer therapy is concerned. The challenges are to have more specific and effective inhibitors with negligible side effects. Moreover, the alterations seen in tumors are not well understood for which one has to gain deeper insight into the tumor pathology as well. Current review focusses on such epigenetic alterations occurring in cancer and the effective strategies to utilize such alterations for potential therapeutic use and treatment in cancer.

A HIF1A/miR-485-5p/SRPK1 axis modulates the aggressiveness of glioma cells upon hypoxia

The high aggressiveness of gliomas remains a huge challenge to clinical therapies, and the hypoxic microenvironment in the core region is a critical contributor to glioma aggressiveness. In this study, it was found that miR-485-5p was low expressed within glioma tissue samples and cells. GO enrichment annotation indicated that the predicted downstream targets miR-485-5p were enriched in hypoxia response and decreased oxygen level. In glioma cells, miR-485-5p overexpression suppressed cell viability, migratory ability, and invasive ability under both normoxic and hypoxic conditions. Through direct binding, miR-485-5p suppressed SRPK1 expression. Under hypoxia, SRPK1 overexpression enhanced hypoxia-induced glioma cell aggressiveness and significantly reversed the effects of miR-485-5p overexpression. Moreover, HIF1A could target the miR-485-5p promoter region to inhibit the transcription. HIF1A, miR-485-5p, and SRPK1 form a regulatory axis, which modulates glioma cell aggressiveness under hypoxia. In conclusion, we identify a HIF1A/miR-485-5p/SRPK1 axis that modulates the aggressiveness of glioma cells under hypoxia. The axis could potentially provide new research avenues in the treatment of gliomas considering the hypoxic environment in its core.

Lead DEAD/H box helicase biomarkers with the therapeutic potential identified by integrated bioinformatic approaches in lung cancer

DEAD/H box helicases are implicated in lung cancer but have not been systematically investigated for their clinical significance and function. In this study, we aimed to evaluate the potential of DEAD/H box helicases as prognostic biomarkers and therapeutic targets in lung cancer by integrated bioinformatic analysis of multivariate large-scale databases. Survival and differential expression analysis of these helicases enabled us to identify four biomarkers with the most significant alterations. These were found to be the negative prognostic factors DDX11, DDX55 and DDX56, and positive prognostic factor DDX5. Pathway enrichment analysis indicates that MYC signalling is negatively associated with expression levels of the DDX5 gene while positively associated with that of DDX11, DDX55 and DDX56. High expression levels of the DDX5 gene is associated with low mutation levels of TP53 and MUC16, the two most frequently mutated genes in lung cancer. In contrast, high expression levels of DDX11, DDX55 and DDX56 genes are associated with high levels of TP53 and MUC16 mutation. The tumour-infiltrated CD8 + T and B cells positively correlate with levels of DDX5 gene expression, while negatively correlate with that of the other three DEAD box helicases, respectively. Moreover, the DDX5-associated miRNA profile is distinguished from the miRNA profiles of DDX11, DDX55 and DDX56, although each DDX has a different miRNA signature. The identification of these four DDX helicases as biomarkers will be valuable for prognostic prediction and targeted therapeutic development in lung cancer.

MicroRNA-16-1-3p Represses Breast Tumor Growth and Metastasis by Inhibiting PGK1-Mediated Warburg Effect

The Warburg effect (aerobic glycolysis) is a hallmark of cancer and is becoming a promising target for diagnosis and therapy. Phosphoglycerate kinase 1 (PGK1) is the first adenosine triphosphate (ATP)-generating glycolytic enzyme in the aerobic glycolysis pathway and plays an important role in cancer development and progression. However, how microRNAs (miRNAs) regulate PGK1-mediated aerobic glycolysis remains unknown. Here, we show that miR-16-1-3p inhibits PGK1 expression by directly targeting its 3′-untranslated region. Through inhibition of PGK1, miR-16-1-3p suppressed aerobic glycolysis by decreasing glucose uptake, lactate and ATP production, and extracellular acidification rate, and increasing oxygen consumption rate in breast cancer cells. Aerobic glycolysis regulated by the miR-16-1-3p/PGK1 axis is critical for modulating breast cancer cell proliferation, migration, invasion and metastasis in vitro and in vivo. In breast cancer patients, miR-16-1-3p expression is negatively correlated with PGK1 expression and breast cancer lung metastasis. Our findings provide clues regarding the role of miR-16-1-3p as a tumor suppressor in breast cancer through PGK1 suppression. Targeting PGK1 through miR-16-1-3p could be a promising strategy for breast cancer therapy.

MicroRNA-Independent Modulation of DICER1 Expression by hAgo2

Many proteins, including DICER1 and hAgo2, are involved in the biogenesis of microRNAs (miRNAs). Whether hAgo2 regulates DICER1 expression is unknown. Exogenously overexpressed hAgo2 suppressed DICER1 expression at the levels of both protein and mRNA, and the reduction in hAgo2 expression enhanced DICER1 expression. Precursor miRNA processing mediated by DICER1 was also modulated by hAgo2. However, hAgo2 protein did not suppress DICER1 promoter activity. Therefore, hAgo2 protein probably regulates DICER1 expression at the posttranscriptional level. Indeed, hAgo2 protein inhibited the reporter assay of the DICER1 mRNA 3' untranslated region (3'-UTR). Previous reports have demonstrated that miRNAs (e.g., let-7 and miR-103/107) inhibited DICER1 expression posttranscriptionally. However, hAgo2 still suppressed DICER1 expression in the cells depleted of these miRNAs. Moreover, the reporter activities of the DICER1 mRNA 3'-UTR without these miRNA binding sites were still suppressed by hAgo2. Therefore, in addition to an miRNA-dependent pathway, hAgo2 can also modulate DICER1 expression through an miRNA-independent mechanism. Downregulation of DICER1 expression was further proven to be dependent on both hAgo2 and AUF1 proteins. Interactions of hAgo2 and AUF1 proteins were demonstrated by the coimmunoprecipitation assay. As expected, hAgo2 could not suppress the DICER1 mRNA 3'-UTR reporter with a mutation in the potential AUF1-binding site. Thus, downregulation of DICER1 expression through the 3'-UTR requires both hAgo2 and AUF1.

MicroRNA-6071 Suppresses Glioblastoma Progression Through the Inhibition of PI3K/AKT/mTOR Pathway by Binding to ULBP2

Objective

The purpose of this study was to explore the effect of microRNA-6071 (miR-6071) on glioblastoma (GBM) and its potential mechanisms.

Methods

In this study, the expressions of miR-6071 and UL16 binding protein 2 (ULBP2) were measured by qRT-RCR in GBM tissues and cells. The prognostic values of miR-6071 and ULBP2 were evaluated by Kaplan–Meier methods using the data obtained from The Cancer Genome Atlas (TCGA) database. The cell clones, proliferation, apoptosis, migration and invasion in GBM cells were detected by colony formation assay, EdU assay, flow cytometry, wound-healing assay and transwell assay. The targeting relationship between miR-6071 and ULBP2 was predicted by Targetscan 7.2 and further verified by dual-luciferase reporter gene assay. Moreover, the expressions of Bax, caspase-3, Bcl-2, matrix metalloproteinases 2 (MMP-2), MMP-9, phosphatidylinositol 3′-kinase (PI3K), p-PI3K, protein kinase B (AKT), p-AKT, mammalian target of rapamycin (mTOR) and p-mTOR were measured by Western blot.

Results

miR-6071 was lowly expressed and ULBP2 was highly expressed in GBM tissues and cells. miR-6071 significantly repressed the proliferation, migration and invasion, and promoted apoptosis in GBM cells. Moreover, miR-6071 also inhibited the activation of PI3K/AKT/mTOR pathway in GBM cells. Additionally, miR-6071 has been shown to negatively regulate ULBP2 expression. We also confirmed that ULBP2 could reverse the effects of miR-6071 on GBM cells through regulating PI3K/AKT/mTOR pathway.

Conclusion

Our study demonstrated that miR-6071 could suppress cell proliferation, migration and invasion, as well as promote apoptosis through the inhibition of PI3K/Akt/mTOR pathway by binding to ULBP2 in GBM.

Uncovering the cellular capacity for intensive and specific feedback self-control of the argonautes and MicroRNA targeting activity

The miRNA pathway has three segments—biogenesis, targeting and downstream regulatory effectors. We aimed to better understand their cellular control by exploring the miRNA-mRNA-targeting relationships. We first used human evolutionarily conserved sites. Strikingly, AGOs 1–3 are all among the top 14 mRNAs with the highest miRNA site counts, along with ANKRD52, the phosphatase regulatory subunit of the recently identified AGO phosphorylation cycle; and the AGO phosphorylation cycle mRNAs share much more than expected miRNA sites. The mRNAs for TNRC6, which acts with AGOs to channel miRNA-mediated regulatory actions onto specific mRNAs, are also heavily miRNA-targeted. In contrast, upstream miRNA biogenesis mRNAs are not, and neither are downstream regulatory effectors. In short, binding site enrichment in miRNA targeting machinery mRNAs, but neither upstream biogenesis nor downstream effector mRNAs, was observed, endowing a cellular capacity for intensive and specific feedback control of the targeting activity. The pattern was confirmed with experimentally determined miRNA-mRNA target relationships. Moreover, genetic experiments demonstrated cellular utilization of this capacity. Thus, we uncovered a capacity for intensive, and specific, feedback-regulation of miRNA targeting activity directly by miRNAs themselves, i.e. segment-specific feedback auto-regulation of miRNA pathway, complementing miRNAs pairing with transcription factors to form hybrid feedback-loop.

Control of Angiogenesis via a VHL/miR-212/132 Axis

A common feature of tumorigenesis is the upregulation of angiogenesis pathways in order to supply nutrients via the blood for the growing tumor. Understanding how cells promote angiogenesis and how to control these processes pharmaceutically are of great clinical interest. Clear cell renal cell carcinoma (ccRCC) is the most common form of sporadic and inherited kidney cancer which is associated with excess neovascularization. ccRCC is highly associated with biallelic mutations in the von Hippel–Lindau (VHL) tumor suppressor gene. Although upregulation of the miR-212/132 family and disturbed VHL signaling have both been linked with angiogenesis, no evidence of a possible connection between the two has yet been made. We show that miRNA-212/132 levels are increased after loss of functional pVHL, the protein product of the VHL gene, in vivo and in vitro. Furthermore, we show that blocking miRNA-212/132 with anti-miRs can significantly alleviate the excessive vascular branching phenotype characteristic of vhl^−/− mutant zebrafish. Moreover, using human umbilical vascular endothelial cells (HUVECs) and an endothelial cell/pericyte coculture system, we observed that VHL knockdown promotes endothelial cells neovascularization capacity in vitro, an effect which can be inhibited by anti-miR-212/132 treatment. Taken together, our results demonstrate an important role for miRNA-212/132 in angiogenesis induced by loss of VHL. Intriguingly, this also presents a possibility for the pharmaceutical manipulation of angiogenesis by modulating levels of MiR212/132.

The role of miRNA biogenesis and DDX17 in tumorigenesis and cancer stemness

Cancer stemness represents one of the major mechanisms that predispose patients to tumor aggressiveness, metastasis, and treatment resistance. MicroRNA biogenesis is an important process controlling miRNA processing and maturation. Deregulation of miRNA biogenesis can lead to tumorigenesis and cancer stemness. DDX17 is a co-factor of the miRNA microprocessor. Misregulation of DDX17 can be associated with cancer stemness. K63-linked polyubiquitination of DDX17 presents a concerted mechanism of decreased synthesis of stemness-inhibiting miRNAs and increased transcriptional activation of stemness-related gene expression. K63-linked polyubiquitination of HAUSP serves as a scaffold to anchor HIF-1α, CBP, the mediator complex, and the super-elongation complex to enhance HIF-1α-induced gene transcription. Recent progress in RNA modifications shows that RNA N6-methyladenosine (m6A) modification is a crucial mechanism to regulate RNA levels. M6A modification of miRNAs can also be linked to tumorigenesis and cancer stemness. Overall, miRNA biogenesis and K63-linked polyubiquitination of DDX17 play an important role in the induction of cancer stemness. Delineation of the mechanisms and identification of suitable targets may provide new therapeutic options for treatment-resistant cancers.

[Down-regulation of miR-381-3p inhibits osteogenic differentiation of mouse embryonic palatal mesenchymal cells in 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin-induced cleft palate of fetal mice]

OBJECTIVE

To investigate the correlation between down-regulation of miR-381-3p and inhibition of osteogenic differentiation of mouse embryonic palatal mesenchymal (MEPM) cells in 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD)-induced cleft palate of fetal mice.

METHODS

Thirty-two pregnant mice were randomly divided into TCDD group and control group, 16 in each group. On embryonic day 10.5 (E10.5), the pregnant mice in TCDD group were orally administrated with TCDD at dosage of 28 μg/kg, while the pregnant mice in control group received equivalent corn oil. The pregnant mice in each group were sacrificed on E13.5 and E14.5, fetal palates were collected for analysis. The expression of miR-381-3p was detected by real-time fluorescent quantitative PCR and the protein expressions of runt- related transcription factor 2 (RUNX2) and osteopontin (OPN) were detected by Western blot. MEPM cells were extracted from fetal palates on E14.5 in control group and passaged. The 3rd passage cells were cultured with TCDD at dosage of 10 nmol/L for 0, 0.5, 1, 2, and 3 days. The expression of miR-381-3p was detected after 0, 0.5, 1, 2, and 3 days and the protein expressions of RUNX2 and OPN were detected after 0, 1, 2, and 3 days. Then, the 3rd passage cells were divided into 4 groups. The MEPM cells were transfected with miR-381-3p inhibitor (inhibitor group), NC inhibitor (NC inhibitor group) and miR-381-3p mimics (mimics group), NC mimics (NC mimics group) for 48 hours, respectively. And the expressions of miR-381-3p and the protein expressions of RUNX2 and OPN were detected.

RESULTS

On E13.5 and E14.5, 96 fetal mice in control group and 92 in TCDD group were obtained. The bilateral palates contacted in control group on E14.5, and a gap between the bilateral palates existed in TCDD group. On E13.5 and E14.5, the relative expressions of miR-381-3p and RUNX2 and OPN proteins were significant lower in TCDD group than in control group ( P<0.05). The relative expression of miR-381-3p at 0.5 and 1 day after TCDD treatment of MEPM cells were significantly lower than that at 0 day ( P<0.05); then, the relative expressions at 2 and 3 days significantly increased, showing no significant difference when compared with that at 0 day ( P>0.05). The relative expressions of RUNX2 and OPN proteins at 1, 2, and 3 days were significantly lower than that at 0 day ( P<0.05). The relative expressions of miR-381-3p and RUNX2 and OPN proteins significantly lower in inhibitor group than in NC inhibitor group ( P<0.05) and higher in mimics group than in NC mimics group ( P<0.05).

CONCLUSION

Down-regulation of miR-381-3p expression may be associated with inhibition of osteogenic differentiation of MEPM cells in TCDD-induced cleft palate of fetal mice.

p73-Governed miRNA Networks: Translating Bioinformatics Approaches to Therapeutic Solutions for Cancer Metastasis

The transcription factor p73 synthesizes a large number of isoforms and presents high structural and functional homology with p53, a well-known tumor suppressor and a famous "Holy Grail" of anticancer targeting. p73 has attracted increasing attention mainly because (a) unlike p53, p73 is rarely mutated in cancer, (b) some p73 isoforms can inhibit all hallmarks of cancer, and (c) it has the ability to mimic oncosuppressive functions of p53, even in p53-mutated cells. These attributes render p73 and its downstream pathways appealing for therapeutic targeting, especially in mutant p53-driven cancers. p73 functions are, at least partly, mediated by microRNAs (miRNAs), which constitute nodal components of p73-governed networks. p73 not only regulates transcription of crucial miRNA genes, but is also predicted to affect miRNA populations in a transcription-independent manner by developing protein-protein interactions with components of the miRNA processing machinery. This combined effect of p73, both in miRNA transcription and maturation, appears to be isoform-dependent and can result in a systemic switch of cell miRNomes toward either an anti-oncogenic or oncogenic outcome. In this review, we combine literature search with bioinformatics approaches to reconstruct the p73-governed miRNA network and discuss how these crosstalks may be exploited to develop next-generation therapeutics.

Autophagy-mediated Mir6981 degradation exhibits CDKN1B promotion of PHLPP1 protein translation

PHLPP1 (PH domain and leucine rich repeat protein phosphatase 1) is a newly identified family of Ser/Thr phosphatases that catalyzes the dephosphorylation of a conserved regulatory motif of the AGC kinases resulting in a tumor suppressive function, while CDKN1B/p27 also acts as a tumor suppressor by regulating cell cycle, senescence, apoptosis, and cell motility. Our most recent studies reveal that CDKN1B is required for PHLPP1 abundance, which contributes to the inhibition of carcinogenic arsenite-induced cell malignant transformation through inhibition of RPS6-mediated Hif1a translation. However, nothing is known about the mechanisms underlying the crosstalk between these 2 key tumor suppressors in intact cells. Here, for the first time to the best of our knowledge, we show that CDKN1B is able to promote PHLPP1 protein translation by attenuating the abundance of Mir6981, which binds directly to the 5'untranslated region (UTR) of Phlpp1 mRNA. Further studies indicate that the attenuation of Mir6981 expression is due to macroautophagy/autophagy-mediated degradation of Mir6981 in an SQSTM1/p62-dependent fashion. Moreover, we have determined that Sqstm1 is upregulated by CDKN1B at the level of transcription via enhancing SP1 protein stability in an HSP90-depdendent manner. Collectively, our studies prove that: 1) SQSTM1 is a CDKN1B downstream effector responsible for CDKN1B-mediated autophagy; 2) by promoting the autophagy-mediated degradation of Mir6981, CDKN1B exerts a positive regulatory effect on PHLPP1 translation; 3) Mir6981 suppresses PHLPP1 translation by binding directly to its mRNA 5'-UTR, rather than classical binding to the 3'-UTR. These findings provide significant insight into understanding the crosstalk between CDKN1B and PHLPP1. Abbreviations: ATG: autophagy related; ACTB: actin beta; BAF: bafilomycin; BECN1: beclin 1; Cdkn1b/p27: cyclin-dependent kinase inhibitor 1B; CHX: cycloheximide; DMEM: dulbecco's modified eagle medium; FBS: fetal bovine serum; GAPDH: glyceraldehyde -3-phosphate dehydrogenase; Hif1a: hypoxia inducible factor 1, alpha subunit; Hsp90: heat shock protein 90; JUN: Jun proto-oncogene, AP1 transcription factor subunit; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MG132: proteasome inhibitor; Mtor: mechanistic target of rapamycin kinase; Phlpp1: PH domain and leucine rich repeat protein phosphatase 1; Phlpp2: PH domain and leucine rich repeat protein phosphatase 2; Pp2c: protein phosphatase 2 C; RPS6: ribosomal protein S6; Sp1: trans-acting transcription factor 1; Sqstm1/p62: sequestosome 1; TUBA: alpha tubulin; 3'-UTR; 3'-untranslated region; 5'-UTR: 5'-untranslated region.

Specificity, versatility, and control of TGF-β family signaling

Encoded in mammalian cells by 33 genes, the transforming growth factor-β (TGF-β) family of secreted, homodimeric and heterodimeric proteins controls the differentiation of most, if not all, cell lineages and many aspects of cell and tissue physiology in multicellular eukaryotes. Deregulation of TGF-β family signaling leads to developmental anomalies and disease, whereas enhanced TGF-β signaling contributes to cancer and fibrosis. Here, we review the fundamentals of the signaling mechanisms that are initiated upon TGF-β ligand binding to its cell surface receptors and the dependence of the signaling responses on input from and cooperation with other signaling pathways. We discuss how cells exquisitely control the functional presentation and activation of heteromeric receptor complexes of transmembrane, dual-specificity kinases and, thus, define their context-dependent responsiveness to ligands. We also introduce the mechanisms through which proteins called Smads act as intracellular effectors of ligand-induced gene expression responses and show that the specificity and impressive versatility of Smad signaling depend on cross-talk from other pathways. Last, we discuss how non-Smad signaling mechanisms, initiated by distinct ligand-activated receptor complexes, complement Smad signaling and thus contribute to cellular responses.

Competing endogenous RNA networks in cervical cancer: function, mechanism and perspective

In the past several years, competing endogenous RNAs (ceRNAs) have emerged as a potential class of post-transcriptional regulators that alter gene expression through a microRNA (miRNA)-mediated mechanism. An increasing number of studies have found that ceRNAs play important roles in tumorigenesis. Cervical cancer is one of the most common cancers in female malignancies. Despite advances in our understanding of this neoplasm, patients with advanced cervical cancer still have poor prognosis. There is an urgent need to provide a new insight on the mechanism of cervical cancer development and may be acted as new anticancer therapeutic strategies. Here, we review the ceRNA studies and coherent researches in cervical cancer, especially in long non-coding RNA (lncRNA) and miRNAs in order to broaden horizons into mechanisms, selection biomarkers for diagnosis as well as predicting prognosis, and targeting treatment for cervical cancer in the future.

Marked disparity of microRNA modulation by cGMP-selective PDE5 versus PDE9 inhibitors in heart disease

MicroRNAs (miRs) posttranscriptionally regulate mRNA and its translation into protein, and are considered master controllers of genes modulating normal physiology and disease. There is growing interest in how miRs change with drug treatment, and leveraging this for precision guided therapy. Here we contrast 2 closely related therapies, inhibitors of phosphodiesterase type 5 or type 9 (PDE5-I, PDE9-I), given to mice subjected to sustained cardiac pressure overload (PO). Both inhibitors augment cyclic guanosine monophosphate (cGMP) to activate protein kinase G, with PDE5-I regulating nitric oxide (NO) and PDE9-I natriuretic peptide-dependent signaling. While both produced strong phenotypic improvement of PO pathobiology, they surprisingly showed binary differences in miR profiles; PDE5-I broadly reduces more than 120 miRs, including nearly half those increased by PO, whereas PDE9-I has minimal impact on any miR (P < 0.0001). The disparity evolves after pre-miR processing and is organ specific. Lastly, even enhancing NO-coupled cGMP by different methods leads to altered miR regulation. Thus, seemingly similar therapeutic interventions can be barcoded by profound differences in miR signatures, and reversing disease-associated miR changes is not required for therapy success.

Prognostic value of miR-17-5p in cancers: a meta-analysis

Background

Studies have shown that miR-17-5p plays an important role in the development of cancer. The aim of this meta-analysis was to quantitatively analyze the association of miR-17-5p with prognosis in various cancers.

Materials and methods

We searched the PubMed, EMBASE, Web of Science, and Cochrane library databases for relevant studies through August 2017. The prognostic data and clinico-pathological features of overall survival (OS) and disease-free survival (DFS) were extracted to investigate the association between miR-17-5p expression and tumor prognosis. In addition, odds ratios (ORs) were used to assess the correlations between miR-17-5p expression and clinicopathological characteristics.

Results

A total of ten studies were incorporated into this systematic review, and we found that high miR-17-5p expression can predict poor OS for malignancies (combined hazard ratio [HR]=1.87; 95% confidence interval [CI], 1.37–2.55; P=0.000) as well as poor DFS (combined HR=1.60; 95% CI, 1.05–2.44; P=0.027). Further subgroup analyses suggested that high miR-17-5p expression was related to poor OS in Asian patients (combined HR=1.92; 95% CI, 1.37–2.71; P=0.000) and the serum/plasma sample source subgroup (combined HR=2.13; 95% CI, 1.36–3.31; P=0.001). The combined OR indicated that the expression of miR-17-5p was associated with lymph node invasion (OR=1.28; 95% CI, 1.05–1.56; P=0.016) and venous invasion (OR=1.92; 95% CI, 1.40–2.63; P=0.000).

Conclusion

Elevated expression of miR-17-5p suggested a poor prognosis in cancer patients and may serve as a new tumor marker to monitor cancer development and progression.

Role of MicroRNAs in Renal Parenchymal Diseases-A New Dimension

Since their discovery in 1993, numerous microRNAs (miRNAs) have been identified in humans and other eukaryotic organisms, and their role as key regulators of gene expression is still being elucidated. It is now known that miRNAs not only play a central role in the processes that ensure normal development and physiology, but they are often dysregulated in various diseases. In this review, we present an overview of the role of miRNAs in normal renal development and physiology, in maladaptive renal repair after injury, and in the pathogenesis of renal parenchymal diseases. In addition, we describe methods used for their detection and their potential as therapeutic targets. Continued research on renal miRNAs will undoubtedly improve our understanding of diseases affecting the kidneys and may also lead to new therapeutic agents.

Circulating miR-31 as an effective biomarker for detection and prognosis of human cancer: a meta-analysis

PURPOSE

Circulating miR-31 was found to be associated with cancers detection and prognosis. The present meta-analysis aimed to explore the effect of circulating miR-31 on cancer detection and prognosis.

METHOD

The studies were accessed using multiple databases. RevMan5.3, Meta-DiSc 1.4, and STATA14.0 were used to estimate the pooled effects, heterogeneity among studies, and publication bias.

RESULTS

A total of 14 studies with 1397 cancer patients and 1039 controls were included. For the 12 prognostic tests, the adjusted pooled-AUC was 0.79 (95% CI: 0.73-0.86) as the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odd ratio (DOR) from 10 tests was 0.79 (95% CI: 0.76-0.82), 0.79 (95% CI: 0.76-0.82), 3.81 (95% CI: 2.90-5.01), 0.26 (95% CI: 0.20-0.35), and 16.81 (95% CI: 9.67-29.25), respectively. For the 5 prognosis analyses, the pooled HR (hazard ratio) of overall survival (OS) was 1.55 (95% CI 1.30-1.86) for high versus low circulating miR-31 expression. However, high expression of circulating miR-31 did not significantly increase the risk of poor differentiation (pooled OR=1.39, 95% CI: 0.56-3.47) and LNM (pooled OR=3.46, 95% CI: 0.96-12.42) in lung cancer.

CONCLUSION

Circulating miR-31 is an effective biomarker and could be used as a component of miRs signature for cancer detection and prognosis surveillance.

MicroRNA-138 promotes acquired alkylator resistance in glioblastoma by targeting the Bcl-2-interacting mediator BIM

Glioblastoma is the most aggressive brain tumor in adults with a median survival below 12 months in population-based studies. The main reason for tumor recurrence and progression is constitutive or acquired resistance to the standard of care of surgical resection followed by radiotherapy with concomitant and adjuvant temozolomide (TMZ/RT→TMZ). Here, we investigated the role of microRNA (miRNA) alterations as mediators of alkylator resistance in glioblastoma cells. Using microarray-based miRNA expression profiling of parental and TMZ-resistant cultures of three human glioma cell lines, we identified a set of differentially expressed miRNA candidates. From these, we selected miR-138 for further functional analyses as this miRNA was not only upregulated in TMZ-resistant versus parental cells, but also showed increased expression in vivo in recurrent glioblastoma tissue samples after TMZ/RT→TMZ treatment. Transient transfection of miR-138 mimics in glioma cells with low basal miR-138 expression increased glioma cell proliferation. Moreover, miR-138 overexpression increased TMZ resistance in long-term glioblastoma cell lines and glioma initiating cell cultures. The apoptosis regulator BIM was identified as a direct target of miR-138, and its silencing mediated the induced TMZ resistance phenotype. Altered sensitivity to apoptosis played only a minor role in this resistance mechanism. Instead, we identified the induction of autophagy to be regulated downstream of the miR-138/BIM axis and to promote cell survival following TMZ exposure. Our data thus define miR-138 as a glioblastoma cell survival-promoting miRNA associated with resistance to TMZ therapy in vitro and with tumor progression in vivo.

MicroRNA in gastrointestinal cell signalling

Our gut forms an important organ and its formation, functioning and homeostasis are maintained by several factors including cell signalling pathways and commensal microflora. These factors affect pathological, physiological and immunological parameters to maintain gut health and prevent its inflammation. Among these, different intracellular signalling pathways play an important role in regulating gut homeostasis. These pathways are in turn regulated by various microRNAs that play a key role in maintaining the balance between tolerance and inflammation. This review highlights the importance of various cell signalling pathways in modulating gut homeostasis and the role specific miRNAs play in their regulation.

MiR-7684-5p leads to surgery-induced cognitive decline in mice probably through the downregulation of SorLA

BACKGROUND

Postoperative cognitive dysfunction is a postoperative severe complication caused by many factors. However, its specific pathogenesis remains unclear. MicroRNAs (miRNAs), which are involved in the pathogenesis of neurodegenerative diseases, may also affect POCD.

METHODS

In this research, microarray technology was used to screen 26 miRNAs that had a differential expression in the hippocampus of mouse between the surgery group and control group. The qRT-PCR verification on the hippocampuses of 10 pairs of mouse testifies the high expression of miR-7684-5p in the surgery group (identical with the result of chip).

RESULTS

Surgical trauma was found to induce the expression of miR-7684-5p with the accumulation of Aβ in the hippocampus. Furthermore, miR-7684-5p knockdown effectively reduced the levels of Aβ triggered by surgery, and attenuated hippocampal-dependent memory impairment. Moreover, we testify that sorLA is a target gene of miR-7684-5p through bioinformatics prediction and dual-luciferase report gene experiment.

CONCLUSIONS

Our data indicate that decreased postoperative cognitive function may be caused by the increased generation of Aβ by reducing sorLA expression. Our work implicates miR-7684-5p as a potential biomarker and a novel therapeutic target.

Research progress on the roles of microRNAs in governing synaptic plasticity, learning and memory

The importance of non-coding RNA involved in biological processes has become apparent in recent years and the mechanism of transcriptional regulation has also been identified. MicroRNAs (miRNAs) represent a class of small regulatory non-coding RNAs of 22bp in length that mediate gene silencing by identifying specific sequences in the target messenger RNAs (mRNAs). Many miRNAs are highly expressed in the central nervous system in a spatially and temporally controlled manner in normal physiology, as well as in certain pathological conditions. There is growing evidence that a considerable number of specific miRNAs play important roles in synaptic plasticity, learning and memory function. In addition, the dysfunction of these molecules may also contribute to the etiology of several neurodegenerative diseases. Here we provide an overview of the current literatures, which support non-coding RNA-mediated gene function regulation represents an important but underappreciated, layer of epigenetic control that facilitates learning and memory functions.

The effect of circulating miR-223 on surveillance of different cancers: a meta-analysis

PURPOSE

Abnormal expression of miR-223 in cancerous tissue has confirmed it as an important player in tumorigenesis of cancers, such as hepatocellular carcinoma, colorectal carcinoma, osteosarcoma, gastric cancer, and chronic lymphocytic leukemia. The present meta-analysis aimed to explore the association between circulating miR-223 and prognosis of cancers.

METHODS

The studies were accessed by an electronic search of multiple databases. RevMan5.3 and STATA14.0 were used to estimate the heterogeneity among studies, pooled effects, and publication bias.

RESULTS

Ten studies with data of 1,002 patients with cancer were included in this meta-analysis. The risk of metastasis from stages 3 to 4 of TNM did not decrease when high versus low circulating expression of miR-223 were compared (pooled odds ratio =0.50, 95% CI: 0.24-1.03). In case of prognosis, the overall survival time was not significantly longer with high circulating miR-223 expression (pooled hazard ratio [HR] =0.64, 95% CI: 0.38-1.11) in all cancer types. However, the overall survival time of chronic lymphocytic leukemia (pooled HR =0.19, 95% CI: 0.07-0.54) increased in subgroup analysis. Moreover, the treatment-free survival of chronic lymphocytic leukemia was significantly increased with high circulating miR-223 expression (pooled HR =0.38, 95% CI: 0.23-0.64).

CONCLUSION

Circulating miR-223 was not an effective biomarker in prognosis surveillance in all cancers but in chronic lymphocytic leukemia.

MicroRNA-592 targets IGF-1R to suppress cellular proliferation, migration and invasion in hepatocellular carcinoma

MicroRNAs (miRs) can function as tumor suppressors or oncogenes in different types of human malignancy, and may provide an effective therapy for cancer. The expression and functions of miR-592 have previously been studied in relation to cancer. However, the expression and potential functions of miR-592 in hepatocellular carcinoma (HCC) are still unknown. Using quantitative polymerase chain reaction, MTT assays, cellular migration and invasion assays, bioinformatics software, western blot analysis and dual-luciferase report assays, the present study explored the expression and roles of miR-592 in HCC. It was identified that miR-592 was significantly downregulated in HCC tissues and cell lines. The statistical analysis revealed that low expression of miR-592 was evidently associated with tumor node metastasis stage and lymph node metastasis. Additionally, the present study provided the first evidence that miR-592 was likely to directly target the insulin-like growth factor 1 receptor in vitro. The present results indicated that miR-592 could be investigated as an efficacious therapeutic target for HCC in the future.

More than Just a Simple Cardiac Envelope; Cellular Contributions of the Epicardium

The adult pumping heart is formed by distinct tissue layers. From inside to outside, the heart is composed by an internal endothelial layer, dubbed the endocardium, a thick myocardial component which supports the pumping capacity of the heart and exteriorly covered by a thin mesothelial layer named the epicardium. Cardiac insults such as coronary artery obstruction lead to ischemia and thus to an irreversible damage of the myocardial layer, provoking in many cases heart failure and death. Thus, searching for new pathways to regenerate the myocardium is an urgent biomedical need. Interestingly, the capacity of heart regeneration is present in other species, ranging from fishes to neonatal mammals. In this context, several lines of evidences demonstrated a key regulatory role for the epicardial layer. In this manuscript, we provide a state-of-the-art review on the developmental process leading to the formation of the epicardium, the distinct pathways controlling epicardial precursor cell specification and determination and current evidences on the regenerative potential of the epicardium to heal the injured heart.

Role of MicroRNA in the Lung's Innate Immune Response

The immune response to respiratory pathogens must be robust enough to defend the host yet properly constrained such that inflammation-induced tissue damage is avoided. MicroRNA (miRNA) are small noncoding RNA which posttranscriptionally influence gene expression. In this review, we discuss recent experimental evidence of the contribution of miRNA to the lung's response to bacterial and viral pathogens.

MicroRNA-298 inhibits malignant phenotypes of epithelial ovarian cancer by regulating the expression of EZH2

MicroRNA (miRNA or miR)-298 has been reported to be downregulated and to modify the expression of the polycomb protein enhancer of zeste 2 (EZH2) in recurrent epithelial ovarian cancer (EOC). To date, no functional evidence of a miR-298-EZH2 axis in EOC has been documented. The present study aimed to investigate the associations of miR-298 and/or EZH2 expression with clinicopathological features of EOC patients, and revealed their roles in cell motility based on EOC cell lines. Reverse transcription-quantitative polymerase chain reaction was performed to detect the expression levels of miR-298 and EZH2 messenger RNA in human EOC tissues and cell lines. Wound healing and transwell assays were performed to determine the function of the miR-298-EZH2 axis on cell migration and invasion, respectively. Compared with normal tissues, miR-298 expression was significantly downregulated, while EZH2 expression was significantly upregulated, in human EOC tissues (both P=0.001). In addition, miR-298 downregulation and EZH2 upregulation were significantly associated with high clinical stage (both P=0.01) and pathological grade (both P=0.02) of EOC patients. Furthermore, the ectopic expression of miR-298 could efficiently inhibit cell migration and invasion. Notably, the overexpression of EZH2 could restore the cell migration and invasion abilities suppressed by miR-298. Our data offer convincing evidence that the dysregulation of the miR-298-EZH2 axis may be important in tumor progression of EOC patients. The present study also confirmed a tumor-suppressive role of miR-298 in modulating EOC cell motility by regulating the expression of EZH2, implying its potential as a novel miRNA-based therapeutic target for the treatment of human EOC.

A Suite of Biochemical Assays for Screening RNA Methyltransferase BCDIN3D

BCDIN3D is an RNA-methyltransferase that O-methylates the 5' phosphate of RNA and regulates microRNA maturation. To discover small-molecule inhibitors of BCDIN3D, a suite of biochemical assays was developed. A radiometric methyltransferase assay and fluorescence polarization-based S-adenosylmethionine and RNA displacement assays are described. In addition, differential scanning fluorimetry and surface plasmon resonance were used to characterize binding. These assays provide a comprehensive package for the development of small-molecule modulators of BCDIN3D activity.

miR-182-5p Induced by STAT3 Activation Promotes Glioma Tumorigenesis

Malignant glioma is an often fatal type of cancer. Aberrant activation of STAT3 leads to glioma tumorigenesis. STAT3-induced transcription of protein-coding genes has been extensively studied; however, little is known about STAT3-regulated miRNA gene transcription in glioma tumorigenesis. In this study, we found that abnormal activation or decreased expression of STAT3 promotes or inhibits the expression of miR-182-5p, respectively. Bioinformatics analyses determined that tumor suppressor protocadherin-8 (PCDH8) is a candidate target gene of miR-182-5p. miR-182-5p negatively regulated PCDH8 expression by directly targeting its 3'-untranslated region. PCDH8 knockdown induced the proliferative and invasive capacities of glioma cells. Silencing of PCDH8 or miR-182-5p mimics could reverse the inhibitory effect of WP1066, a STAT3 inhibitor, or STAT3 knockdown in vitro and in vivo on glioma progression. Clinically, expression levels of PCDH8 were inversely correlated with those of p-STAT3 or miR-182-5p in glioblastoma tissues. These findings reveal that the STAT3/miR-182-5p/PCDH8 axis has a critical role in glioma tumorigenesis and that targeting the axis may provide a new therapeutic approach for human glioma. Cancer Res; 76(14); 4293-304. ©2016 AACR.

Exosomes miR-126a released from MDSC induced by DOX treatment promotes lung metastasis

Acquired resistance to chemotherapy remains a major stumbling block in cancer treatment. Chronic inflammation plays a crucial role in induction of chemo resistance, and results in part from the induction and expansion of inflammatory cells that include myeloid derived suppressor cells (MDSC) and IL-13⁺Th2 cells. The mechanisms that lead to induction of activated MDSCs and IL-13⁺Th2 cells have not yet been identified. Here we demonstrated that doxorubicin treatment of 4T1 breast tumor bearing mice led to the induction of IL-13R⁺miR-126a⁺MDSC (DOX-MDSC). DOX-MDSC promote breast tumor lung metastasis through MDSC miR-126a⁺exosomal mediated induction of IL-13⁺Th2 cells and tumor angiogenesis. The induction of DOX-MDSC is regulated in a paracrine manner. DOX treatment not only increases IL-33 released from breast tumor cells, which is crucial for the induction of IL-13⁺Th2 cells, but it also participates in the induction of IL-13 receptors and miR-126a expressed on/in the MDSCs. IL-13 released from IL-13⁺Th2 cells then promotes the production of DOX-MDSC and MDSC miR-126a⁺exosomes via MDSC IL-13R. MDSC miR-126a⁺exosomes further induce IL13⁺Th2 cells in a positive feed-back loop manner. We also showed that MDSC miR-126a rescues doxorubicin induced MDSC death in a S100A8/A9 dependent manner and promotes tumor angiogenesis. Our findings provide insight into the MDSC exosomal mediated chemo resistance mechanism, which will be useful for the design of inhibitors targeting the blocking of induction of miR-126a⁺MDSC.

Oncogenic role of microRNA‑20a in human uveal melanoma

As a member of the microRNA (miR)-17-92 cluster, miR‑20a has been indicated to be involved in the regulation of the proliferation and invasion of various cancer cells. Previous studies have observed elevated plasma levels of miR‑20a in patients with uveal melanoma (UM), compared with normal controls. In the present study, the potential function of miR‑20a in UM was investigated. Reverse transcription‑quantitative polymerase chain reaction analysis was performed to detect the expression levels of miR‑20a in UM cells and tissues. The functions of miR‑20a on cell proliferation, migration and invasion were determined in vitro using 3‑(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide and Transwell assays, respectively. The expression levels of miR‑20a were significantly increased in the UM cells and tissues (P<0.05). Subsequently, miR‑20a mimics were transfected into UM cells, which led to increases in cell growth, migration and invasion activities. By contrast, miR‑20a inhibition markedly suppressed the viability and motility of UM cells in vitro. These data provided convincing evidence that miR‑20a may function as an oncogenic miRNA, and may be involved in promoting cell growth and motility in the molecular etiology of UM, suggesting its potential as a candidate therapeutic target for the treatment of patients with UM.

A ceRNA approach may unveil unexpected contributors to deletion syndromes, the model of 5q- syndrome

In genomic deletions, gene haploinsufficiency might directly configure a specific disease phenotype. Nevertheless, in some cases no functional association can be identified between haploinsufficient genes and the deletion-associated phenotype. Transcripts can act as microRNA sponges. The reduction of transcripts from the hemizygous region may increase the availability of specific microRNAs, which in turn may exert in-trans regulation of target genes outside the deleted region, eventually contributing to the phenotype. Here we prospect a competing endogenous RNA (ceRNA) approach for the identification of candidate genes target of epigenetic regulation in deletion syndromes. As a model, we analyzed the 5q- myelodysplastic syndrome. Genes in haploinsufficiency within the common 5q deleted region in CD34+ blasts were identified in silico. Using the miRWalk 2.0 platform, we predicted microRNAs whose availability, and thus activity, could be enhanced by the deletion, and performed a genomewide analysis of the genes outside the 5q deleted region that could be targeted by the predicted miRNAs. The analysis pointed to two genes with altered expression in 5q- transcriptome, which have never been related with 5q- before. The prospected approach allows investigating the global transcriptional effect of genomic deletions, possibly prompting discovery of unsuspected contributors in the deletion-associated phenotype. Moreover, it may help in functionally characterizing previously reported unexpected interactions.

MicroRNA-328 enhances cellular motility through posttranscriptional regulation of PTPRJ in human hepatocellular carcinoma

OBJECTIVE

Interaction between microRNA (miR-328) and PTPRJ (protein tyrosine phosphatase, receptor type, J) has been reported to be responsible for miR-328-dependent increase in epithelial cancer cell proliferation. However, the role of miR-328 and PTPRJ in hepatocellular carcinoma (HCC) remains unclear. The aim of this study was to investigate the clinical significance of miR-328 and/or PTPRJ expression in human HCC and determine their precise biological functions in this malignancy.

METHODS

Expression levels of miR-328 and PTPRJ messenger RNA (mRNA) in 100 pairs of HCC and adjacent noncancerous tissues were detected using quantitative real-time reverse transcription polymerase chain reaction. The associations between miR-328 and/or PTPRJ expression and various clinicopathological features of HCC patients were further statistically assessed. Then, the functions of miR-328 and PTPRJ in migration and invasion of two human HCC cell lines were determined by transwell assays.

RESULTS

miR-328 and PTPRJ mRNA expression levels were markedly upregulated and down-regulated in HCC tissues, respectively, compared to adjacent noncancerous tissues. Notably, the upregulation of miR-328 in HCC tissues was significantly correlated with the downregulation of PTPRJ mRNA in HCC tissues (r=-0.362, P=0.01). In addition, miR-328-high and/or PTPRJ-low expression were found to be closely correlated with high Edmondson-Steiner grading (all P<0.05) and advanced tumor-node-metastasis stage (all P<0.05). Moreover, the restoration of miR-328 dramatically promoted HCC cell migration and invasion by repressing PTPRJ expression. Interestingly, the loss of PTPRJ expression could significantly attenuate the inhibitory effects of knockdown miR-328 on the migration and invasion of HCC cells.

CONCLUSION

These findings demonstrated that the dysregulation of miR-328 and PTPRJ may be associated with tumor progression of HCC patients. Functionally, miR-328 may serve as a crucial oncogene and be implicated in the motility of HCC cells at least in part by the suppression of PTPRJ.

The Biological Functions of Non-coding RNAs: From a Line to a Circle

Non-coding RNAs have gained increasing attention, as their physiological and pathological functions are being gradually uncovered. MicroRNAs are the most well-studied ncRNAs, which play essential roles in translational repression and mRNA degradation. In contrast, long non-coding RNAs are distinguished from other small/short non-coding RNAs by length and regulate chromatin remodeling, gene transcription and posttranscriptional modifications. Recently, circular RNAs have emerged as endogenous, abundant, conserved and stable in mammalian cells. It has been demonstrated that circular RNAs can function as miRNA sponges. Other possible biological functions of circular RNAs are still under investigation. In this review, the biogenesis and biological functions of the three major types of ncRNAs, including miRNAs, lncRNAs and circRNAs, are overviewed. In addition, the role of ncRNAs in human diseases and potential clinical applications of ncRNAs are discussed.

MicroRNA Regulation of Airway Inflammation and Airway Smooth Muscle Function: Relevance to Asthma

Genetic and environmental factors contribute to the onset and severity of asthma. Molecular pathogenesis of asthma involves changes in gene expression by a variety of inflammatory mediators acting in autocrine and paracrine fashion on effector cells of the airways. Transcriptional regulation of gene expression in resident airway cells has been studied extensively. However, protein function in a target cell can be regulated at multiple levels starting from transcription followed by post-transcription, translation, and post-translation steps. In this context, small noncoding RNAs known as microRNAs (miRNAs) have evolved as one of the key regulators of gene expression post-transcriptionally. Most importantly, miRNA expression is dynamic in nature and can be regulated by a variety of external stimuli. Altered expression of individual or a group of miRNAs is thought to contribute to human diseases. Recent studies have implicated differential expression of miRNAs in the lungs during inflammation. Most importantly, advanced biochemical and molecular tools could be used to manipulate miRNA expression thereby effecting functional changes in target cells and organ systems. This review summarizes the current understanding of miRNA in the regulation of airway function in health and disease, and highlights the potential clinical utility of mRNAs as biomarkers of airway diseases and as potential therapeutic targets.

Could MicroRNA polymorphisms influence warfarin dosing? A pharmacogenetics study on mir133 genes

MicroRNAs are small single stranded molecules that play a crucial role in regulation of physiological and pathological processes. Recent studies showed that VKORC1 gene contains an highly evolutionary conserved binding site for mir-133. Moreover, in human hepatocytes mir-133 is constitutively co-expressed with VKORC1. Since VKORC1 protein is the target of warfarin treatment, the aim of this study was to verify if genetic variations in MIR133A1, MIR133A2 and MIR133B could contribute to warfarin dose variability. By direct sequencing, we identified 4 SNPs in MIR133A2 gene and 1 SNP in MIR133B gene. Three SNPs in MIR133A2 were in complete linkage disequilibrium and correlated with warfarin dose: indeed, for each SNP, patients carrying the GA or AA genotype required a MWWD significantly higher than the wildtype genotype (P=0.019). We also inferred the haplotypes in MIR133A2 gene. The GC haplotype required a MWWD significantly lower than AT haplotype (P=0.012). The multiple linear regression analysis confirmed that rs45547937 (as tag SNP) in MIR133A2 could be involved in warfarin dosing variability, (P=0.016). These results seem to suggest that also polymorphisms in miRNA precursors may potentially affects drug response variability.