Cross-talk between miRNA and Notch signaling pathways in tumor development and progression

Regulation of the Notch signaling pathway by natural products for cancer therapy

The Notch signaling pathway is an evolutionarily conserved pathway that modulates normal biological processes involved in cellular differentiation, apoptosis, and stem cell self-renewal in a context-dependent fashion. Attributed to its pleiotropic physiological roles, both overexpression and silencing of the pathway are associated with the emergence, progression, and poorer prognosis in various types of cancer. To decrease disease incidence and promote survival, targeting Notch may have chemopreventive and anti-cancer effects. Natural products with profound historical origins have distinguished themselves from other therapies due to their easy access, high biological compatibility, low toxicity, and reliable effects at specific physiological sites in vivo. This review describes the Notch signaling pathway, particularly its normal activation process, and some main illnesses related to Notch signaling pathway dysregulation. Emphasis is placed on the effects and mechanisms of natural products targeting the Notch signaling pathway in diverse cancer types, including curcumin, ellagic acid (EA), resveratrol, genistein, epigallocatechin-3-gallate (EGCG), quercetin, and xanthohumol and so on. Existing evidence indicates that natural products are feasible solution to fight against cancer by targeting Notch signaling, either alone or in combination with current therapeutic agents.

The epigenetics orchestra of Notch signaling: a symphony for cancer therapy

The aberrant regulation of the Notch signaling pathway, which is a fundamental developmental pathway, has been implicated in a wide range of human cancers. The Notch pathway can be activated by both canonical and noncanonical Notch ligands, and its role can switch between acting as an oncogene or a tumor suppressor depending on the context. Epigenetic modifications have the potential to modulate Notch and its ligands, thereby influencing Notch signal transduction. Consequently, the utilization of epigenetic regulatory mechanisms may present novel therapeutic opportunities for both single and combined therapeutics targeted at the Notch signaling pathway. This review offers insights into the mechanisms governing the regulation of Notch signaling and explores their therapeutic potential.

Epigenetic control of cell signalling in cancer stem cells

The self-renewing cancer stem cells (CSCs) represent one of the distinct cell populations occurring in a tumour that can differentiate into multiple lineages. This group of sparsely abundant cells play a vital role in tumour survival and resistance to different treatments during cancer. The lack of exclusive markers associated with CSCs makes diagnosis and prognosis in cancer patients extremely difficult. This calls for the identification of unique regulators and markers for CSCs. Various signalling pathways like the Wnt/β-catenin pathway, Hedgehog pathway, Notch pathway, and TGFβ/BMP play a major role in the regulation and maintenance of CSCs. Epigenetic regulatory mechanisms add another layer of complexity to control these signalling pathways. In this chapter, we discuss about the role of epigenetic mechanisms in regulating the cellular signalling pathways in CSCs. The epigenetic regulatory mechanisms such as DNA methylation, histone modification and microRNAs can modulate the diverse effectors of signalling pathways and consequently the growth, differentiation and tumorigenicity of CSCs. In the end, we briefly discuss the therapeutic potential of targeting these epigenetic regulators and their target genes in CSCs.

miRNAs as potential game-changers in bone diseases: Future medicinal and clinical uses

MicroRNAs (miRNAs), short, highly conserved non-coding RNA, influence gene expression by sequential mechanisms such as mRNA breakdown or translational repression. Many biological processes depend on these regulating substances, thus changes in their expression have an impact on the maintenance of cellular homeostasis and result in the emergence of a variety of diseases. Relevant studies have shown in recent years that miRNAs are involved in many stages of bone development and growth. Additionally, abnormal production of miRNA in bone tissues has been closely associated with the development of numerous bone disorders, such as osteonecrosis, bone cancer, and bone metastases. Many pathological processes, including bone loss, metastasis, the proliferation of osteosarcoma cells, and differentiation of osteoblasts and osteoclasts, are under the control of miRNAs. By bringing together the most up-to-date information on the clinical relevance of miRNAs in such diseases, this study hopes to further the study of the biological features of miRNAs in bone disorders and explore their potential as a therapeutic target.

miRNAs as cornerstones in chronic lymphocytic leukemia pathogenesis and therapeutic resistance- An emphasis on the interaction of signaling pathways

Chronic lymphocytic leukemia (CLL) accounts for the vast majority of cases of leukemia. Patients of advanced age are more likely to develop the condition, which has a highly varied clinical course. Consideration of illness features and preceding treatment sequence, as well as patient preferences and comorbidities, is necessary for selecting the appropriate treatment for the appropriate patient. Therefore, there is an urgent need for novel biomarkers with high sensitivity and specificity to detect CLL early, monitor CLL patients, select the treatment responders, and reduce ineffective treatment, unwanted side effects, and unnecessary expenses. In both homeostasis and illness, microRNAs (miRNAs/miRs) play a vital role as master regulators of gene expression and, by extension, protein expression. MiRNAs typically reduce the stability of mRNAs, including those encoding genes involved in tumorigenesis processes as cell cycle regulation, inflammation, stress response, angiogenesis, differentiation, apoptosis, and invasion. Due to their unique properties, miRNAs are rapidly being exploited as accurate biomarkers for illness detection, and medicines based on miRNA targets are finding widespread application in clinical practice. Accordingly, the current review serves as a quick primer on CLL and the biogenesis of miRNAs. In addition to providing a brief overview of the miRNAs whose function in the progression of CLL has been established by recent in vitro or in vivo research through articulating the influence of these miRNAs on a wide variety of cellular functions, including increased proliferative potential; support for angiogenesis; cell cycle aberration; evasion of apoptosis; promotion of metastasis; and reduced sensitivity to specific treatments.

MicroRNA-506 as a tumor suppressor in anaplastic thyroid carcinoma by regulation of WNT and NOTCH signaling pathways

Objectives

Anaplastic thyroid carcinoma (ATC) is an aggressive thyroid tumor type that has a poor prognosis due to its high therapeutic resistance. Since ATC accounts for half of thyroid cancer-related deaths, it is required to introduce novel therapeutic targets to increase survival in ATC patients. WNT and NOTCH signaling pathways are the pivotal regulators of cell proliferation and migration that can be regulated by microRNAs. We assessed the role of miR-506 in the regulation of cell migration, apoptosis, and drug resistance via NOTCH and WNT pathways in ATC cells.

Materials and Methods

The levels of miR-506 expressions were assessed in ATC cells and tissues. The levels of NOTCH, WNT, and EMT-related gene expressions were also assessed in miR-506 ectopic expressed cells compared with controls. Cell migration and drug resistance were also evaluated to assess the role of miR-506 in the regulation of ATC aggressiveness.

Results

There were significant miR-506 down-regulations in ATC cells and clinical samples compared with normal cells and margins. MiR-506 suppressed NOTCH and WNT signaling pathways through LEF1, DVL, FZD1, HEY2, HES5, and HEY2 down-regulations, and APC and GSK3b up-regulations. MiR-506 significantly inhibited ATC cell migration and EMT (P=0.028). Moreover, miR-506 significantly increased Cisplatin (P=0.004), Paclitaxel (P<0.0001), and Doxorubicin (P=0.0014) sensitivities in ATC cells.

Conclusion

MiR-506 regulated EMT, cell migration, and chemoresistance through regulation of WNT and NOTCH signaling pathways in ATC cells. Therefore, after confirmation with animal studies, it can be introduced as an efficient novel therapeutic factor for ATC tumors.

Expression profiling of inflammation-related genes including IFI-16, NOTCH2, CXCL8, THBS1 in COVID-19 patients

The present study aimed to scrutinize the expression profile of inflammatory-related genes (IFI-16, NOTCH2, CXCL8, and THBS1) from acute to post-acute stage of this infectious epidemic. The current cross-sectional study consisted of 53 acute-phase COVID-19 patients and 53 healthy individuals between February and March 2021. The extraction of total RNA was performed from PBMC specimens and also expression level of selected genes (IFI-16, NOTCH2, CXCL8, and THBS1) was evaluated by real-time PCR. Subsequently, levels of these factors were re-measured six weeks after the acute phase to determine if the levels of chosen genes returned to normal after the acute phase of COVID-19. Receiver operating characteristic (ROC) curve was plotted to test potential of genes as a diagnostic biomarker. The expression levels of inflammatory-related genes were significantly different between healthy and COVID-19 subjects. Besides, a significant higher CXCL8 level was found in the acute-phase COVID-19 compared to post-acute-phase infection which may be able to be considered as a potential biomarker for distinguishing between the acute phases from the post-acute-phase status. Deregulation of the inflammatory-related genes in COVID-19 patients, especially CXCL-8, can be serving as potent biomarkers to manage the COVID-19 infection.

CEMIP Promotes Osteosarcoma Progression and Metastasis Through Activating Notch Signaling Pathway

Cell migration inducing protein (CEMIP) has been linked to carcinogenesis in several types of cancers. However, the role and mechanism of CEMIP in osteosarcoma remain unclear. This study investigated the role of CEMIP in the progression and metastasis of osteosarcoma, CEMIP was found to be overexpressed in osteosarcoma tissues when compared to adjacent non-tumor tissues, and its expression was positively associated with a poor prognosis in osteosarcoma patients. Silencing CEMIP decreased osteosarcoma cells proliferation, migration, and invasion, but enhanced apoptosis in vitro, and suppressed tumor growth and metastasis in vivo. Mechanistically, CEMIP promoted osteosarcoma cells growth and metastasis through activating Notch signaling pathway, silencing CEMIP would reduce the protein expression and activation of Notch/Jagged1/Hes1 signaling pathway in vitro and in vivo, activation of Notch signaling pathway could partially reversed cell proliferation and migration in shCEMIP osteosarcoma cells. In conclusion, our study demonstrated that CEMIP plays a substantial role in the progression of osteosarcoma via Notch signaling pathway, providing a promising therapeutic target in osteosarcoma.

Non-classical Notch signaling by MDA-MB-231 breast cancer cell-derived small extracellular vesicles promotes malignancy in poorly invasive MCF-7 cells

Aberrant Notch signaling is implicated in breast cancer progression, and recent studies have demonstrated links between the Notch pathway components Notch1 and Notch1 intracellular domain (N1ICD) with poor clinical outcomes. Growing evidence suggests that Notch signaling can be regulated by small extracellular vesicles (SEVs). Here, we used breast cancer cell models to examine whether SEVs are involved in functional Notch signaling. We found that Notch components are packaged into MDA-MB-231- and MCF-7-derived SEVs, although higher levels of N1ICD were detected in SEVs from the more aggressive MDA-MB-231 cell line than from poorly invasive MCF-7 cells. SEV-Notch components were functional, as SEVs cargo from MDA-MB-231 cells induced the expression of Notch target genes in MCF-7 cells and triggered a more invasive and proliferative phenotype concomitant with the acquisition of mesenchymal features. Neutralization of the N1ICD cargo in MDA-MB-231-derived SEVs significantly reduced their potential to enhance the aggressiveness of MCF-7 cells in vitro and in a xenograft model. Overall, our results indicate that a SEV-mediated non-classical pathway of Notch signal transduction in breast cancer models bypasses the need for classical ligand-receptor interactions, which may have important implications in cancer.

Dysregulated Notch Signaling in the Airway Epithelium of Children with Wheeze

The airway epithelium of children with wheeze is characterized by defective repair that contributes to disease pathobiology. Dysregulation of developmental processes controlled by Notch has been identified in chronic asthma. However, its role in airway epithelial cells of young children with wheeze, particularly during repair, is yet to be determined. We hypothesized that Notch is dysregulated in primary airway epithelial cells (pAEC) of children with wheeze contributing to defective repair. This study investigated transcriptional and protein expression and function of Notch in pAEC isolated from children with and without wheeze. Primary AEC of children with and without wheeze were found to express all known Notch receptors and ligands, although pAEC from children with wheeze expressed significantly lower NOTCH2 (10-fold, p = 0.004) and higher JAG1 (3.5-fold, p = 0.002) mRNA levels. These dysregulations were maintained in vitro and cultures from children with wheeze displayed altered kinetics of both NOTCH2 and JAG1 expression during repair. Following Notch signaling inhibition, pAEC from children without wheeze failed to repair (wound closure rate of 76.9 ± 3.2%). Overexpression of NOTCH2 in pAEC from children with wheeze failed to rescue epithelial repair following wounding. This study illustrates the involvement of the Notch pathway in airway epithelial wound repair in health and disease, where its dysregulation may contribute to asthma development.

Key miRNAs in Modulating Aging and Longevity: A Focus on Signaling Pathways and Cellular Targets

Aging is a multifactorial procedure accompanied by gradual deterioration of most biological procedures of cells. MicroRNAs (miRNAs) are a class of short non-coding RNAs that post-transcriptionally regulate the expression of mRNAs through sequence-specific binding, and contributing to many crucial aspects of cell biology. Several miRNAs are expressed differently in various organisms through aging. The function of miRNAs in modulating aging procedures has been disclosed recently with the detection of miRNAs that modulate longevity in the invertebrate model organisms, through the IIS pathway. In these model organisms, several miRNAs have been detected to both negatively and positively regulate lifespan via commonly aging pathways. miRNAs modulate age-related procedures and disorders in different mammalian tissues by measuring their tissue-specific expression in older and younger counterparts, including heart, skin, bone, brain, and muscle tissues. Moreover, several miRNAs have been contributed to modulating senescence in different human cells, and the roles of these miRNAs in modulating cellular senescence have allowed illustrating some mechanisms of aging. The review discusses the available data on miRNAs through the aging process and we highlight the roles of miRNAs as aging biomarkers and regulators of longevity in cellular senescence, tissue aging, and organism lifespan.

Epigenetic Regulation of Breast Cancer Stem Cells Contributing to Carcinogenesis and Therapeutic Implications

Globally, breast cancer has remained the most commonly diagnosed cancer and the leading cause of cancer death among women. Breast cancer is a highly heterogeneous and phenotypically diverse group of diseases, which require different selection of treatments. Breast cancer stem cells (BCSCs), a small subset of cancer cells with stem cell-like properties, play essential roles in breast cancer progression, recurrence, metastasis, chemoresistance and treatments. Epigenetics is defined as inheritable changes in gene expression without alteration in DNA sequence. Epigenetic regulation includes DNA methylation and demethylation, as well as histone modifications. Aberrant epigenetic regulation results in carcinogenesis. In this review, the mechanism of epigenetic regulation involved in carcinogenesis, therapeutic resistance and metastasis of BCSCs will be discussed, and finally, the therapies targeting these biomarkers will be presented.

Therapeutic effect of curcumin in gastrointestinal cancers: A comprehensive review

Gastrointestinal (GI) cancers with a high global prevalence are a leading cause of morbidity and mortality. Accordingly, there is a great need to develop efficient therapeutic approaches. Curcumin, a naturally occurring agent, is a promising compound with documented safety and anticancer activities. Recent studies have demonstrated the activity of curcumin in the prevention and treatment of different cancers. According to systematic studies on curcumin use in various diseases, it can be particularly effective in GI cancers because of its high bioavailability in the gastrointestinal tract. Nevertheless, the clinical applications of curcumin are largely limited because of its low solubility and low chemical stability in water. These limitations may be addressed by the use of relevant analogues or novel delivery systems. Herein, we summarize the pharmacological effects of curcumin against GI cancers. Moreover, we highlight the application of curcumin's analogues and novel delivery systems in the treatment of GI cancers.

Ganoderma lucidum triterpenoids and polysaccharides attenuate atherosclerotic plaque in high-fat diet rabbits

BACKGROUND AND AIMS

Atherosclerosis is characterized by lipid deposition, oxidative stress, and inflammation in the arterial intima. Ganoderma lucidum triterpenoids (GLTs) and polysaccharides (GLPs) are traditional Chinese medicines with potential cardiovascular benefits. We aimed to comprehensively evaluate the effect of GLTs and GLPs on atherosclerosis and the associated underlying mechanisms in vivo and in vitro.

METHODS AND RESULTS

Japanese big-ear white rabbits were randomly divided into three groups of blank, model, and treatment, and the treatment group was fed with GLSO and GLSP (0.3 g/kg body-weight/day) for 4 months. Serum levels of triglyceride (TG), total (TC), and low density lipoprotein cholesterol (LDL-C) in GL treatment group were significantly lower than those in the model group. The area of aortic plaques was significantly reduced in the treatment group. Further, GL administration in oxidized low-density lipoprotein (ox-LDL) stimulated human umbilical vein endothelial cells (HUVECs) reduced the generation of reactive oxygen species (ROS) and malondialdehyde (MDA) by inhibiting the upregulation of the nuclear transcription factor (NF)-κB p65 and the relative receptor LOX-1. In THP-1 cells treated with phorbol myristate acetate, GL inhibited the inflammatory polarization of macrophages (as evidenced by reduced TNF-α levels) via regulation of Notch1 and DLL4 pathways. Ox-LDL-stimulated THP-1 cells treated with GL showed an increase in the apoptosis of foam cells.

CONCLUSIONS

GLTs and GLPs attenuated the progression of atherosclerosis by alleviating endothelial dysfunction and inflammatory polarization of macrophages, thus promoting apoptosis of foam cells.

miRNA signaling networks in cancer stem cells

Cancer stem cells (CSCs) are a small cell subpopulation in many cancer types and are involved in various processes of tumor progression, such as initiation, metastasis and recurrence. The distinguished features of CSCs include a variety of biological properties, including self-renewal, multidifferentiation, stemness marker expression, and resistance to chemotherapy and radiotherapy. Despite their great potential of clinical importance, the CSC signaling pathways are not well understood at the molecular level. MicroRNAs (miRNAs) are a class of endogenous noncoding RNAs that play an important role in the regulation of several cellular, physiological, and developmental processes. Aberrant miRNA expression is associated with many human diseases, including cancer. miRNAs have been implicated in the regulation of CSC properties; therefore, a better understanding of miRNA-induced modulation of CSC gene expression could aid in the identification of promising biomarkers and therapeutic targets. In the present review, we summarize the major findings of the impacts of miRNAs on CSC signaling networks; we then discuss the recent advances that have improved our understanding of CSC regulation by miRNA-mediated signaling networks and that may lead to the development of miRNA therapeutics specifically targeting CSCs.

Cancer stem cells targets and combined therapies to prevent cancer recurrence

Cancer stem cells (CSCs) control the dynamics of tumorigenesis by self-renewal ability and differentiation potential. These properties contribute towards tumor malignancy, metastasis, cellular heterogeneity, and immune escape, which are regulated by multiple signaling pathways. The CSCs are chemoresistant and cause cancer recurrence, generally recognized as a small side-population that eventually leads to tumor relapse. Despite many treatment options available, none can be considered entirely efficient due to a lack of specificity and dose limitation. This review primarily highlights the processes involved in CSCs development and maintenance. Secondly, the current effective therapies based on stem cells, cell-free therapies that involve exosomes and miRNAs, and photodynamic therapy have been discussed. Also, the inhibitors that specifically target various signaling pathways, which can be used in combination to control CSCs kinetics have been highlighted. Conclusively, this comprehensive review is a detailed study of recently developed novel treatment strategies that will facilitate in coming up with better-targeted approaches against CSCs.

RUNX2 as a promising therapeutic target for malignant tumors

The transcription factor runt-related protein 2 (RUNX2) has an important impact on the transformation of bone marrow mesenchymal stem cells to osteoblasts. Further studies have shown that RUNX2 plays a key role in the invasion and metastasis of cancers. RUNX2 is a “key” molecule in the regulatory network comprised of multiple signaling pathways upstream and its target downstream molecules. Due to the complex regulatory mechanisms of RUNX2, the specific mechanism underlying the occurrence, development and prognosis of malignant tumors has not been fully understood. Currently, RUNX2 as a promising therapeutic target for cancers has become a research hotspot. Herein, we reviewed the current literature on the modulatory functions and mechanisms of RUNX2 in the development of malignant tumors, aiming to explore its potential clinical application in the diagnosis, prognosis and treatment of tumors.

Changes in NOTCH1 gene and its regulatory circRNA, hsa_circ_0005986 expression pattern in human gastric adenocarcinoma and human normal fibroblast cell line following the exposure to extremely low frequency magnetic field

The effect of an extremely low-frequency magnetic field (ELF-MFs) on the expression levels of NOTCH1 and its regulatory circular RNA (circ-RNA) in gastric cancer has not yet investigated. This study aimed to find the expression changes of NOTCH1 and its regulatory circ-RNA, hsa_circ_0005986, in human gastric adenocarcinoma cell line (AGS) and human normal fibroblast (Hu02) cells fallowing the exposure to discontinuously magnetic flux densities (MFDs) of 0.25, 0.5 ,1 and 2 millitesla (mT) for 18h in comparison to unexposed cells. In addition, the effect of various MFDs on viability of tumor and normal cells was investigated. The cell viability was evaluated by MTT assay. The relative expression of NOTCH1and hsa_circ_0005986 mRNAs was analyzed by quantitative Real-time PCR. The viability of tumor cells was decreased under the exposure of MFs, while the normal cells viability was increased. NOTCH1 was significantly down-regulated in AGS cells and up-regulated in Hu02 cells at all MFDs. The expression changes of NOTCH1 in tumor and  normal cells was depended to the MFD of MFs. According to our results, the tumor and normal cells show different behavior at the molecular level in various MFDs in terms of NOTCH1 and hsa_circ_0005986 expression level. Decrease in tumor cell survival following the exposure to ELF-MFs may be the result of decreased in the expression level of NOTCH1 and its Reg-circ-RNA. These magnetic field-reducing effects on cancer cell survival through the change on the expression of genes involved in the proliferation and progression of cancer can be a new key in cancer treatment.

Downregulation of lncRNA SNHG14 attenuates osteoarthritis by inhibiting FSTL-1 mediated NLRP3 and TLR4/NF-κB pathway through miR-124-3p

Osteoarthritis (OA) is the joint pain and dysfunction syndrome caused by severe joint degeneration. The overproduced inflammatory mediators contribute greatly to OA development. It is reported that long non-coding RNA (lncRNA) takes part in many inflammatory diseases. Here, we mainly explored the function of lncRNA SNHG14 in OA process and its specific mechanisms. An OA rat model was induced by destabilizing the medial meniscus (DMM) and IL-1β (5 ng/mL) was used to mediate an OA cell model in particular chondrocytes (AC). Gain- or loss-of functional assays of SNHG14 and miR-124-3p were carried out to explore their roles in OA development. The experimental statistics illustrated that lncRNA SNHG14 and IL-1β mRNA expression were both increased in OA tissues, while miR-124-3p was lowly-expressed. Linear regression analysis showed that SNHG14 and miR-124-3p had negative relationship in the OA tissues. In the in vitro experiments, downregulation of lncRNA SNHG14 promoted the proliferation of IL-1β-treated AC and inhibited cell apoptosis and COX-2, iNOS, TNF-α, IL-6 expression. Moreover, lncRNA SNHG14 inhibited miR-124-3p expression as a miRNA sponge. MiR-124-3p targeted the 3'non-translated region (3'UTR) of FSTL-1 and TLR4 and inhibited their expressions. Also, the in vivo experiments confirmed that knocking down SNHG14 relieved the progression of OA in rats via inhibiting inflammatory responses. In conclusion, this study confirmed that downregulation of lncRNA SNHG14 inhibits FSTL-1-mediated activation of NLRP3 and TLR4/NF-κB signalling pathway activation by targeting miR-124-3p, thus attenuating inflammatory reactions in OA.

Novel Tyrosine Kinase Targets in Urothelial Carcinoma

Urothelial carcinoma represents one of the most prevalent types of cancer worldwide, and its incidence is expected to grow. Although the treatment of the advanced disease was based on chemotherapy for decades, the developments of different therapies, such as immune checkpoint inhibitors, antibody drug conjugates and tyrosine kinase inhibitors, are revolutionizing the therapeutic landscape of this tumor. This development coincides with the increasing knowledge of the pathogenesis and genetic alterations in urothelial carcinoma, from the non-muscle invasive setting to the metastatic one. The purpose of this article is to provide a comprehensive review of the different tyrosine kinase targets and their roles in the therapeutic scene of urothelial carcinoma.

Breast tumor cells promotes the horizontal propagation of EMT, stemness, and metastasis by transferring the MAP17 protein between subsets of neoplastic cells

MAP17 (PDZK1IP1) is a small protein regulating inflammation and tumor progression, upregulated in a broad range of carcinomas. MAP17 levels increase during tumor progression in a large percentage of advanced tumors. In the present work, we explored the role of this protein shaping tumor evolution. Here we show that in breast cancer, cells increased MAP17 levels in tumors by demethylation induced multiple changes in gene expression through specific miRNAs downregulation. These miRNA changes are dependent on Notch pathway activation. As a consequence, epithelial mesenchymal transition (EMT) and stemness are induced promoting the metastatic potential of these cells both in vitro and in vivo. Furthermore, MAP17 increased the exosomes in tumor cells, where MAP17 was released as cargo, and this horizontal propagation also increased the EMT in the recipient cells. Importantly, an antibody against MAP17 in the media reduces the EMT and stemness alterations promoted by the conditioned media from MAP17-expressing cells. Therefore, MAP17 expression promotes the horizontal propagation of EMT and metastasis by transferring the MAP17 protein between subsets of neoplastic cells. Thus, MAP17 can be used to describe a new mechanism for cell malignity at distance, without the involvement of genetic or epigenetic modifications. MAP17 can also be taken in consideration as new target for metastatic high-grade breast tumors.

microRNA-1271-5p/TIAM1 suppresses the progression of ovarian cancer through inactivating Notch signaling pathway

Objective

Ovarian cancer (OC) has been regarded as the most malignant gynecological neoplasm and often confers grave outcomes owing to the frequent metastasis and high recurrence. A previous study has demonstrated that miR-1271-5p is implicated in OC progression, however, the possible mechanism of it remains unknown. The purpose of this investigation was to explore how miR-1271-5p regulates the progression of OC.

Methods

Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases were employed to analyze the differentially expressed miRNAs or genes as well as their corresponding prognostic values. miR-1271-5p expression in OC cells was examined by qRT-PCR. Cell counting kit 8 (CCK-8), colony formation, and transwell tests were conducted to evaluate the proliferation, migration and invasion potentials. Bioinformatics prediction and luciferase activity analysis were utilized to predict and verify the target gene of miR-1271-5p. Western blot assay was carried out to measure protein expression.

Results

miR-1271-5p was significantly decreased in OC and its down-regulation was associated with the grave outcome of OC patients. Upregulation of miR-1271-5p inhibited cell viability, but miR-1271-5p knockdown promoted the proliferation of OC cells. TIAM1 was a direct target gene of miR-1271-5p and expressed in OC tissues at higher level. High expression of TIAM1 induced the poorer prognosis of patients with OC. Further functional analyses showed that the suppressive role of miR-1271-5p on OC cell malignant behaviors was overturned by the upregulation of TIAM1. The protein levels of Cyclin D1, HES1, NOTCH and NUMB were remarkably changed due to the abnormal expression of miR-1271-5p and TIAM1.

Conclusion

To sum up, miR-1271-5p inhibits proliferation, invasion and migration of OC cells by directly repressing TIAM1 to inactivate the Notch signaling pathway, which provides an alternative therapeutic candidate for the advancement of OC treatment.

CircAPLP2 regulates the proliferation and metastasis of colorectal cancer by targeting miR-101-3p to activate the Notch signalling pathway

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers, and it has a poor prognosis. Emerging evidence shows that circular RNAs (circRNAs) may act as good therapeutic targets for cancers due to their abundance and stability. However, their regulatory role in CRC needs further investigation. This study revealed that circAPLP2 was upregulated and miR-101-3p was downregulated in CRC tissues and cells compared to normal controls. Knockdown of circAPLP2 and overexpression of miR-101-3p inhibited the cell proliferation, migration and invasion and induced the apoptosis of CRC cells. circAPLP2 acted as a miR-101-3p sponge to upregulate its target gene Notch1, which activated cascades of proliferation- and metastasis-related proteins (c-Myc, cyclin D1, MMP-2 and MMP-9). Additionally, knockdown of circAPLP2 suppressed tumour growth and liver metastases of CRC in nude mice. Taken together, these results indicate that circAPLP2 promotes proliferation and metastasis by targeting miR-101-3p to activate the Notch signalling pathway in CRC, which provides new insights into the mechanisms underlying CRC malignancy and suggests a new therapeutic target.

MicroRNA-216a inhibits neuronal apoptosis in a cellular Parkinson's disease model by targeting Bax

The study found that microRNAs play an important role in Parkinson's disease (PD). However, the function of MicroRNA-216a (miR-216a) in PD is unclear. Therefore, this experiment aimed to investigate the pathogenesis of miR-216a in PD. Using the toxicity of MPP+ to polyhexamine neurons, apoptosis of SH-SY5Y neuroblastoma cells was induced at different time by MPP+ to construct a stable acute PD cell model. The effects of DNA breakage, mitochondrial membrane potential (A ^ m), caspase-3 activity and nucleosome enrichment on cell apoptosis were detected by flow cytometry, TUNEL. MPP+ increased the toxic effects of dopaminergic neurons in a PD model. The introduction of miR-216a inhibited MPP + -induced neuronal apoptosis. The main manifestations were the decreased levels of positive rate of Tunel cells, caspase 3 activity and nucleosome enrichment factor. Bax was a direct target of miR-216a. In addition, Bax overexpression reversed the effects of miR-216a on neural cells. Bax downstream factors were also involved in miR-216a regulation of MPP + -triggered neuronal apoptosis. miR-216a regulated the progression of PD by regulating Bax, and miR-216a may be a potential target for PD.

Interaction of Long Noncoding RNAs and Notch Signaling: Implications for Tissue Homeostasis Loss

The Notch signaling is a crucial pathway involved in cellular development, progression, and differentiation. Deregulation of Notch signaling pathway commonly impacts tissue homeostasis, being highly associated with proliferative disorders. The long noncoding RNAs (lncRNAs), which are transcripts with more than 200 nucleotides that do not code for proteins, were already described as Notch signaling pathway-interacting molecules. Many of them act as important transcriptional and posttranscriptional regulators, affecting gene expression and targeting other regulatory molecules, such as miRNAs. Due to their strong impact on function and gene expression of Notch-related molecules, lncRNAs influence susceptibility to cancer and other diseases, and can be regarded as potential biomarkers and therapeutic targets. Along this chapter, we summarize the cross talk between the Notch signaling pathway and their most important modulating lncRNAs, as well as the pathological consequences of these interactions, in different tissues.

Expression Profiles of MicroRNAs in Stem Cells Differentiation

Stem cells are undifferentiated cells and have a great potential in multilineage differentiation. These cells are classified into adult stem cells like Mesenchymal Stem Cells (MSCs) and Embryonic Stem Cells (ESCs). Stem cells also have potential therapeutic utility due to their pluripotency, self-renewal, and differentiation ability. These properties make them a suitable choice for regenerative medicine. Stem cells differentiation toward functional cells is governed by different signaling pathways and transcription factors. Recent studies have demonstrated the key role of microRNAs in the pathogenesis of various diseases, cell cycle regulation, apoptosis, aging, cell fate decisions. Several types of stem cells have different and unique miRNA expression profiles. Our review summarizes novel regulatory roles of miRNAs in the process of stem cell differentiation especially adult stem cells into a variety of functional cells through signaling pathways and transcription factors modulation. Understanding the mechanistic roles of miRNAs might be helpful in elaborating clinical therapies using stem cells and developing novel biomarkers for the early and effective diagnosis of pathologic conditions.

The potential mechanism of miR-130b on promotion of the invasion and metastasis of hepatocellular carcinoma by inhibiting Notch-Dll1

Introduction: This study aimed to elucidate the regulatory role and molecular regulation mechanism of miR-130b gene in the process of invasion and metastasis of hepatocarcinoma, and provide a theoretical basis for seeking of effective prevention and treatment of new targets for hepatocellular carcinoma.Materials and methods: The expression level of miR-130b gene in hepatocarcinoma tissues was determined by qRT-PCR. The biological function and mechanism of miR-130b gene were verified by cell and animal models, and the target gene was verified by double luciferase assay.Results: In the liver cancer tissues of patients with metastasis, the expression level of miR-130b gene was increased, and the difference was significantly significant (p < 0.05). Evaluation of independent risk factors for overall survival showed significant difference (p < 0.01). Up-regulation of miR-130b in MHCC97L- subpopulation cells significantly enhanced the invasion and migration ability, and the difference was statistically significant (p < 0.05). The invasion and migration ability of MHCC97H + subpopulation cells with increased expression of miR-130b was significantly decreased, and the difference was notably significant (p < 0.05). When the expression of miR-130b in MHCC97H + subpopulation cells was inhibited, the expressions of Notch-Dll1 and SOX2, Nanog and E2F3 proteins in transplanted tumor tissues were significantly higher than those in other groups (p < 0.05). When miR-130b in MHCC97L- subpopulation cells was up-regulated, the expressions of Notch-Dll1 and Bcl-2, CCND1, Nanog and MET proteins in transplanted tumor tissues were significantly increased than those in other groups (p < 0.05). The prediction results of bioinformatics data suggest that the target gene of miR-130b may be Notch-Dll1 gene. The experiment of luciferase reporter gene confirmed that miR-130b gene can be inhibited and contains fluorescent reporter gene with complementary binding site, lost activity.Conclusion: The miR-130b gene can inhibit the protein expression of Notch-Dll1, and it can promote the invasion and metastasis of liver cancer cells.

LeukmiR: a database for miRNAs and their targets in acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is one of the most common hematological malignancies in children. Recent studies suggest the involvement of multiple microRNAs in the tumorigenesis of various leukemias. However, until now, no comprehensive database exists for miRNAs and their cognate target genes involved specifically in ALL. Therefore, we developed 'LeukmiR' a dynamic database comprising in silico predicted microRNAs, and experimentally validated miRNAs along with the target genes they regulate in mouse and human. LeukmiR is a user-friendly platform with search strings for ALL-associated microRNAs, their sequences, description of target genes, their location on the chromosomes and the corresponding deregulated signaling pathways. For the user query, different search modules exist where either quick search can be carried out using any fuzzy term or by providing exact terms in specific modules. All entries for both human and mouse genomes can be retrieved through multiple options such as miRNA ID, their accession number, sequence, target genes, Ensemble-ID or Entrez-ID. User can also access miRNA: mRNA interaction networks in different signaling pathways, the genomic location of the targeted regions such as 3'UTR, 5'UTR and exons with their gene ontology and disease ontology information in both human and mouse systems. Herein, we also report 51 novel microRNAs which are not described earlier for ALL. Thus, LeukmiR database will be a valuable source of information for researchers to understand and investigate miRNAs and their targets with diagnostic and therapeutic potential in ALL. Database URL: http://tdb.ccmb.res.in/LeukmiR/.

Long Noncoding RNA Nuclear Enriched Abundant Transcript 1 (NEAT1) Regulates Proliferation, Apoptosis, and Inflammation of Chondrocytes via the miR-181a/Glycerol-3-Phosphate Dehydrogenase 1-Like (GPD1L) Axis

Background

Osteoarthritis (OA) is one of the most common chronic musculoskeletal diseases, yet to date it lacks effective therapeutic strategies. Increasing evidence suggests that long noncoding RNAs (lncRNAs) serve pivotal roles in the occurrence and development of OA. However, the possible molecular mechanism involving lncRNAs, such as nuclear enriched abundant transcript 1 (NEAT1), in OA progression is still unclear.

Material/Methods

First, NEAT1 and miR-181a expression in OA synovium tissues and normal synovium tissues were detected. Then, the effect of NEAT1 on modulating growth ability, apoptosis, and inflammation in OA chondrocytes was investigated by a series of loss-function experiments. Next, the correlation between NEAT1, miR-181a, and glycerol-3-phosphate dehydrogenase 1-like (GPD1L) was fully investigated. Finally, the downregulation of miR-181a was employed as a recovery experiment to explore the functional mechanism of NEAT1 in OA.

Results

In the present study, we found that NEAT1 expression was downregulated in OA tissues, while miR-181a expression was prominently upregulated. Moreover, reduced expression of NEAT1 suppressed cell growth while elevating the apoptotic rate and increasing the abundance of inflammatory cytokines released in OA chondrocytes. Furthermore, we clarified that miR-181a was a direct sponge of NEAT1, and GPD1L was able to bind to miR-181a. Additionally, we found that downregulation of miR-181a was able to attenuate the effect of NEAT1 on apoptosis, inflammatory response, and proliferation in OA chondrocytes.

Conclusions

Our findings indicate that downregulation of NEAT1 aggravated progression of OA via modulating the miR-181a/GPD1L axis, providing a novel insight into the mechanism of OA pathogenesis.

MicroRNA-16 is involved in the pathogenesis of pre-eclampsia via regulation of Notch2

In recent years, the role of microRNAs (miRNAs) in pre-eclampsia (PE) has been demonstrated, while the relevant mechanisms of miR-16 in PE await to be unearthed. Thus, the aim of this study is to explore whether miR-16 exerts its function in PE, and we assumed that miR-16 may be implicated in the occurrence of PE by adjusting the biological functions of trophoblast cells via modulating Notch2. Placental tissues of pregnant women with normal pregnancy and PE were collected to detect the expression of miR-16, Notch2, and Notch3. The effects of miR-16 and Notch2 on the biological functions of BeWo and JEG-3 cells were further determined. Expression of miR-16 and Notch2 in trophoblast cells was detected by reverse transcription quantitative polymerase chain reaction and western blot assay. Downregulated Notch2 and upregulated miR-16 and Notch3 were found in placental tissues of PE. There was a negative correlation between Notch2 and miR-16 expression (r = -0.769), and a positive correlation between Notch3 and miR-16 expression (r = 0.676; p < .05). Overexpression of miR-16 inhibited proliferation, migration, and invasion, and facilitated the apoptosis of BeWo and JEG-3 cells, but overexpression of Notch2 reversed this trend. Overexpression of miR-16 inhibited Notch2 expression in BeWo and JEG-3 cells, and Notch2 was the target gene of miR-16. Our study highlights that overexpression of miR-16 is involved in PE by regulating the biological functions of trophoblast cells via inhibition of Notch2. This paper provides a new idea for further study of the pathogenesis of PE.

MicroRNA-494 induces breast cancer cell apoptosis and reduces cell viability by inhibition of nicotinamide phosphoribosyltransferase expression and activity

Breast cancer (BC) is the most prevalent cause of cancer-related death in women worldwide. BC is frequently associated with elevated levels of nicotinamide phosphoribosyltransferase (NAMPT) in blood and tumor tissue. MicroRNA-494 (miR-494) has been described to play key anti-tumor roles in human cancers. The aim of the present study was to investigate the inhibitory effect of miR-494 on NAMPT-mediated viability of BC cells. In this experimental study, MCF-7 and MDA-MB-231 cells were cultured and then transfected with miR-494 mimic, miR-494 inhibitor and their negative controls. The mRNA and protein expression of NAMPT were assessed using real-time PCR and Western blotting, respectively. Subsequently, intracellular NAD levels were determined by a colorimetric method. Finally, cell apoptosis was examined by flow cytometry. Bioinformatics evaluations predicted NAMPT as a miR-494 target gene which was confirmed by luciferase reporter assay. Our results showed an inverse relationship between the expression of miR-494 and NAMPT in both MCF-7 and MDA-MB-231 cell lines. miR-494 significantly down-regulated NAMPT mRNA and protein expression and was also able to reduce the cellular NAD content. Cell viability was decreased following miR-494 up-regulation. In addition, apoptosis was induced in MCF-7 and MDA-MB-231 cells by miR-494 mimic. Our findings indicate that miR-494 acts as a tumor suppressor and has an important effect in suppressing the growth of BC cells through NAMPT. Therefore, miR-494 might be considered as a novel therapeutic target for the management of human breast cancer.

The Roles of miRNAs in Medulloblastoma: A Systematic Review

Medulloblastoma is considered one of the most threatening malignant brain tumors with an extremely high mortality rate in children. In the medulloblastoma, there are several genes and mutations found to work in an unregulated manner that works together to push the cells into a cancerous state. With the discovery of non-coding RNAs such as microRNAs (miRNAs), it has been shown that a different layer of gene regulations may be disrupted which would cause cancer. This fact led scientists to put their focus on the role of miRNAs in cancer. A mature miRNA contains a seed sequence which gives the miRNA to identify and attach to the interest mRNA; this attachment may lead degradation of mRNA or suppress of translation of the mRNA. The expression of miRNAs in medulloblastoma shows that some of these non-coding RNAs are overexpressed (OncomiRs) which help cells to proliferate and keep their stemness features. On the other hand, there are other forms of these miRNAs which normally inhibit cell proliferation and promote cell differentiation (tumor suppressor). These are down-regulated during cancer progression. In this systematic review, we attempted to gather several important studies on miRNAs’ role in medulloblastoma tumors and the importance of these non-coding RNAs in the future study of cancer.

Dual regulation of lin28a by Myc is necessary during zebrafish retina regeneration

Cellular reprogramming leading to induction of Muller glia-derived progenitor cells (MGPCs) with stem cell characteristics is essential for zebrafish retina regeneration. Although several regeneration-specific genes are characterized, the significance of MGPC-associated Mycb induction remains unknown. Here, we show that early expression of Mycb induces expression of genes like ascl1a, a known activator of lin28a in MGPCs. Notably, mycb is simultaneously activated by Ascl1a and repressed by Insm1a in regenerating retina. Here, we unravel a dual role of Mycb in lin28a expression, both as an activator through Ascl1a in MGPCs and a repressor in combination with Hdac1 in neighboring cells. Myc inhibition reduces the number of MGPCs and abolishes normal regeneration. Myc in collaboration with Hdac1 inhibits her4.1, an effector of Delta-Notch signaling. Further, we also show the repressive role of Delta-Notch signaling on lin28a expression in post-injured retina. Our studies reveal mechanistic understanding of Myc pathway during zebrafish retina regeneration, which could pave way for therapeutic intervention during mammalian retina regeneration.

Aberrant miRNAs Regulate the Biological Hallmarks of Glioblastoma

GBM is the highest incidence in primary intracranial malignancy, and it remains poor prognosis even though the patient is gave standard treatment. Despite decades of intense research, the complex biology of GBM remains elusive. In view of eight hallmarks of cancer which were proposed in 2011, studies related to the eight biological capabilities in GBM have made great progress. From these studies, it can be inferred that miRs, as a mode of post-transcriptional regulation, are involved in regulating these malignant biological hallmarks of GBM. Herein, we discuss state-of-the-art research on how aberrant miRs modulate the eight hallmarks of GBM. The upregulation of 'oncomiRs' or the genetic loss of tumor suppressor miRs is associated with these eight biological capabilities acquired during GBM formation. Furthermore, we also discuss the applicable clinical potential of these research results. MiRs may aid in the diagnosis and prognosis of GBM. Moreover, miRs are also therapeutic targets of GBM. These studies will develop and improve precision medicine for GBM in the future.

Aptamers as targeting ligands and therapeutic molecules for overcoming drug resistance in cancers

Traditional anticancer therapies are often unable to completely eradicate the tumor bulk due to multi-drug resistance (MDR) of cancers. A number of mechanisms such as micro-environmental stress and overexpression of drug efflux pumps are involved in the MDR process. Hence, therapeutic strategies for overcoming MDR are urgently needed to improve cancer treatment efficacy. Aptamers are short single-stranded oligonucleotides or peptides exhibiting unique three-dimensional structures and possess several unique advantages over conventional antibodies such as low immunogenicity and stronger tissue-penetration capacity. Aptamers targeting cancer-associated receptors have been explored to selectively deliver a therapeutic cargo (anticancer drugs, siRNAs, miRNAs and drug-carriers) to the intratumoral compartment where they can exert better tumor-killing effects. In this review, we summarize current knowledge of the multiple regulatory mechanisms of MDR, with a particular emphasis on aptamer-mediated novel therapeutic agents and strategies that seek to reversing MDR. The challenges associated with aptamer-based agents and approaches are also discussed.

NFIX Circular RNA Promotes Glioma Progression by Regulating miR-34a-5p via Notch Signaling Pathway

Objective: The present study aimed to explore the association between NFIX circular RNA (circNFIX) and miR-34a-5p in glioma. Furthermore, this study investigated the influence that circNFIX has on glioma progression through the upregulation of NOTCH1 via the Notch signaling pathway by sponging miR-34a-5p.

Methods: We applied five methods, CIRCexplorer2, circRNA-finder, CIRI, find-circ and MapSplice2, to screen for circRNAs with differential expression between three glioma tissue samples and three paired normal tissue samples. The GSEA software was used to confirm whether significantly different pathways were activated or inactivated in glioma tissues. The binding sites between circNFIX and miR-34a-5p were confirmed by TargetScan. QRT-PCR and western blot were used to measure the relative expression levels of circNFIX, miR-34a-5p and NOTCH and identify their correlation in glioma. RNA immunoprecipitation (RIP) validated the binding relationship between circNFIX and miR-34a-5p, while the targeted relationship between NOTCH1 and miR-34a-5p was verified by a dual luciferase reporter assay. Cell viability and mobility were examined by a CCK-8 assay and wound healing assay, and a flow cytometry assay was employed to analyze cell apoptosis. The nude mouse transplantation tumor experiment verified that si-circNFIX exerted a suppressive effect on glioma progression in vivo.

Results: Twelve circRNAs were differentially expressed between the tissue types. Of those, circNFIX was the sole circRNA to be overexpressed in glioma among the five methods of finding circRNAs. In addition, the Notch signaling pathway was considerably upregulated in tumor tissues compared with the paired normal brain tissues. It was determined that circNFIX acted as a sponge of miR-34a-5p, a miRNA that targeted NOTCH1. Downregulation of circNFIX and upregulation of miR-34a-5p both inhibited cell propagation and migration. Furthermore, a miR-34a-5p inhibitor neutralized the suppressive effect of si-circNFIX on glioma cells. Si-circNFIX and miR-34a-5p mimics promoted cell apoptosis. Moreover, it was demonstrated in vivo that si-circNFIX could suppress glioma growth by regulating miR-34a-5p and NOTCH1.

Conclusion: CircNFIX was markedly upregulated in glioma cells. CircNFIX could regulate NOTCH1 and the Notch signaling pathway to promote glioma progression by sponging miR-34a-5p via the Notch signaling pathway. This finding provided a deeper insight into the function of circNFIX in human glioma cancer progression.

Cross-regulation between Notch signaling pathway and miRNA machinery in cancer

Despite their simple structure, the Notch family of receptors regulates a wide-spectrum of key cellular processes including development, tissue patterning, cell-fate determination, proliferation, differentiation and, cell death. On the other hand, accumulating date pinpointed the role of non-coding microRNAs, namely miRNAs in cancer initiation/progression via regulating the expression of multiple oncogenes and tumor suppressor genes, as such the Notch signaling. It is now documented that these two partners are in one or in the opposite directions and rule together the cancer fate. Here, we review the current knowledge relevant to this tricky interplay between different miRNAs and components of Notch signaling pathway. Further, we discuss the implication of this crosstalk in cancer progression/regression in the context of cancer stem cells, tumor angiogenesis, metastasis and emergence of multi-drug resistance. Understanding the molecular cues and mechanisms that occur at the interface of miRNA and Notch signaling would open new avenues for development of novel and effective strategies for cancer therapy.

Notch1 pathway-mediated microRNA-151-5p promotes gastric cancer progression

Gastric carcinoma is the third leading cause of lethal cancer worldwide. Previous studies showed that Notch1 receptor intracellular domain (N1IC), the activated form of Notch1 receptor, promotes gastric cancer progression. It has been demonstrated that a significant cross-talk interplays between Notch pathways and microRNAs (miRNAs) in controlling tumorigenesis. This study identified an intronic microRNA-151 (miR-151), which consists of two mature miRNAs, miR-151-3p and miR-151-5p, as a Notch1 receptor-induced miRNA in gastric cancer cells. Activation of Notch1 pathway enhanced expressions of miR-151 and its host gene, focal adhesion kinase (FAK), in gastric cancer cells. The levels of miR-151 in gastric cancer samples were higher than those of adjacent non-tumor samples. Activated Notch1 pathway induced CBF1-dependent FAK promoter activity. The ectopic expression of miR-151 promoted growth and progression of SC-M1 gastric cancer cells including cell viability and colony formation, migration, and invasion abilities. Activated Notch1 pathway could augment progression of gastric cancer cells through miR-151-5p and FAK. The mRNA levels of pluripotency genes, Nanog and SOX-2, tumorsphere formation ability, tumor growth, and lung metastasis of SC-M1 cells were elevated by activated Notch1 pathway through miR-151-5p. Furthermore, miR-151-5p could target 3′-untranslated region (3′-UTR) of p53 mRNA and down-regulate p53 level in SC-M1 cells. Mechanistically, Notch1/miR-151-5p axis contributed to progression of SC-M1 cells through down-regulation of p53 which in turn repressed FAK promoter activity. Taken together, these results suggest that Notch1 pathway and miR-151-5p interplay with p53 in a reciprocal regulation loop in controlling gastric carcinogenesis.

Crosstalk between the Notch signaling pathway and long non-coding RNAs

The Notch signaling pathway has a key role in cellular development and is involved in initiation and progression of cancer by fundamentally influencing cellular processes such as differentiation, proliferation or migration. The pathway is regulated on many stages, generating diverse outcomes depending on cellular context or signaling dose. Recent studies suggest that long non-coding RNAs (lncRNAs), a class of non-coding RNAs deregulated in many cancers, are involved in regulating the Notch pathway activity by modulating the expression of receptors or ligands on transcriptional or posttranscriptional levels. LncRNAs are also downstream targets of Notch signaling and some of these Notch-induced lncRNAs have been reported to be inducers of its oncogenic effects. This cross-talk between Notch signaling and lncRNAs makes those molecules potential biomarkers for Notch signaling activity and interesting therapeutic RNA-based targets in the future.

MicroRNAs as effective surrogate biomarkers for early diagnosis of oral cancer

BACKGROUND

Oral squamous cell carcinomas (OC) are life-threatening diseases emerging as major international health concerns.

OBJECTIVE

Development of an efficient clinical strategy for early diagnosis of the disease is a key for reducing the death rate. Biomarkers are proven to be an effective approach for clinical diagnosis of cancer. Although mechanisms underlying regulation of oral malignancy are still unclear, microRNAs (miRNAs) as a group of small non-coded RNAs may be developed as the effective biomarkers used for early detection of oral cancer.

METHODS

A literature search was conducted using the databases of PubMed, Web of Science, and the Cochrane Library. The following search terms were used: miRNAs and oral cancer or oral carcinoma. A critical appraisal of the included studies was performed with upregulated miRNAs and downregulated miRNAs in oral cancer.

RESULTS

In this review, we summarize the research progress made in miRNAs for diagnosis of oral cancer. The involvement of miRNAs identified in signal transduction pathways in OC, including Ras/MAPK signaling, PI3K/AKT signaling, JAK/STAT signaling, Wnt/β-catenin signaling, Notch signaling, and TGF-β/SMAD signaling pathway.

CONCLUSIONS

A number of studies demonstrated that miRNAs may be developed as an ideal set of biomarkers used for early diagnosis and prognosis of cancers because of the stability in human peripheral blood and body fluids and availability of non-invasive approaches being developed for clinical utility.

CLINICAL RELEVANCE

These findings suggest that miRNAs as biomarkers may be useful for diagnosis of OC.

In vivo and in vitro effects of microRNA-124 on human gastric cancer by targeting JAG1 through the Notch signaling pathway

In this study, we aim to determine the function of miR-124 on gastric cancer (GC) cells and the underlying mechanism that involves jaddeg1 (JAG1) and the Notch signaling pathway. GC tissues and adjacent tissues from 100 patients suffering from GC were selected. GC SGC-7901 and AGS cells were selected and grouped into control, mimic-NC, miR-124 mimic, inhibitor-NC, miR-124 inhibitor, and miR-124 inhibitor + si-JAG1 groups. RT-qPCR and a Western blotting assay were conducted to detect the expression of miR-124, JAG1, and Notch signaling pathway-related proteins (NICD, HES1, and HES5). MTS, wound-healing, transwell assay and flow cytometry were performed to detect cell proliferation, migration, invasion, cell cycle distribution, and apoptosis, respectively. Compared with adjacent tissues, a lower miR-124 expression and higher JAG1 expression were found in GC tissues. JAG1 is a direct target gene of miR-124. Compared with the control group, the expression of JAG1, NICD, HES1, and HES5, cell invasion, migration, and proliferation in the miR-124 mimic group were decreased, while the apoptosis rate was increased and cells were arrested at the G0/G1 phase. Compared with the miR-124 inhibitor group, the expression of JAG1, NICD, HES1, and HES5, cell invasion, migration, and proliferation in the miR-124 inhibitor + si-JAG1 group were decreased, while the apoptosis rate and cell ratio at the G0/G1 phase were increased. The demonstration that miR-124 inhibits GC cell growth supports the concept that miR-124 functions as a tumor suppressor by a mechanism that involves translational repression of the JAG1 and the inhibition of Notch signaling pathway.

Crosstalk between the Notch signaling pathway and non-coding RNAs in gastrointestinal cancers

The Notch signaling pathway is one of the main signaling pathways that mediates direct contact between cells, and is essential for normal development. It regulates various cellular processes, including cell proliferation, apoptosis, migration, invasion, angiogenesis and metastasis. It additionally serves an important function in tumor progression. Non-coding RNAs mainly include small microRNAs, long non-coding RNAs and circular RNAs. At present, a large body of literature supports the biological significance of non-coding RNAs in tumor progression. It is also becoming increasingly evident that cross-talk exists between Notch signaling and non-coding RNAs. The present review summarizes the current knowledge of Notch-mediated gastrointestinal cancer cell processes, and the effect of the crosstalk between the three major types of non-coding RNAs and the Notch signaling pathway on the fate of gastrointestinal cancer cells.

MicroRNA‑141 inhibits the self‑renewal of glioblastoma stem cells via Jagged1

Glioblastoma multiforme is one of the most lethal types of brain cancer. With limited success from conventional therapies, the cancer stem cell theory was developed, and investigation into microRNAs (miRs) has facilitated understanding of this theory. The present study demonstrated that miR-141 is suppressed in sorted cluster of differentiation (CD) 133(+) glioblastoma stem cells (GSCs) compared with CD133(−) non-glioblastoma stem cells (NSCs) from patient samples. In addition, miR-141 overexpression inhibited the sphere formation ability of GSCs in vitro and in vivo. Furthermore, Jagged1 may reverse the effect of miR-141; miR-141 was revealed to target the 3′-untranslated region of Jagged1, thereby inhibiting the stemness of GSCs. Thus, miR-141 may serve as a potent antioncomir targeting cancer stem cells, and may facilitate the development of therapeutic targets to prolong the overall survival of patients with glioblastoma.

miR-181a Modulates Chondrocyte Apoptosis by Targeting Glycerol-3-Phosphate Dehydrogenase 1-Like Protein (GPD1L) in Osteoarthritis

BACKGROUND miR-181a is a small non-coding RNA known to be dysregulated in osteoarthritis (OA), but the role of miR-181a in human OA remains unclear. The aim of this study was to identify its function and molecular target in chondrocytes during OA pathogenesis. MATERIAL AND METHODS The function of miR-181a was assessed by gain-of-function studies in human OA chondrocytes. Potential targets of miR-181a were predicted using series of bioinformatics and intersection analysis, then confirmed by luciferase reporter assay. Gene expression was quantified using quantitative reverse transcription PCR (qRT-PCR) assays, and protein production was quantified by Western blot analysis. RESULTS The FITC apoptosis assay results indicated that the upregulation of miR-181a led to an increase of apoptosis rate in chondrocytes. Then bioinformatic analysis identified potential target sites of the miR-181a located in the 3' untranslated region of GPD1L. Dual-luciferase reporter assays results showed that GPD1L is a target gene of miR-181a. Furthermore, Western blot and qRT-PCR analysis demonstrated that miR-181a inhibited GPD1L gene expression. Increased GPD1L and decreased miRNA-181a were observed in tissues from osteoarthritis patients. Moreover, we found a highly negative correlation between miRNA-181a and GPD1L. CONCLUSIONS Our results demonstrated that miR-181a may play an important role in the pathogenesis of OA through targeting GPD1L and regulating chondrocyte apoptosis.