Induction of differentiation by down-regulation of Nanog and Rex-1 in cord blood derived unrestricted somatic stem cells

Advanced theragnostics for the central nervous system (CNS) and neurological disorders using functional inorganic nanomaterials

Various types of inorganic nanomaterials are capable of diagnostic biomarker detection and the therapeutic delivery of a disease or inflammatory modulating agent. Those multi-functional nanomaterials have been utilized to treat neurodegenerative diseases and central nervous system (CNS) injuries in an effective and personalized manner. Even though many nanomaterials can deliver a payload and detect a biomarker of interest, only a few studies have yet to fully utilize this combined strategy to its full potential. Combining a nanomaterial's ability to facilitate targeted delivery, promote cellular proliferation and differentiation, and carry a large amount of material with various sensing approaches makes it possible to diagnose a patient selectively and sensitively while offering preventative measures or early disease-modifying strategies. By tuning the properties of an inorganic nanomaterial, the dimensionality, hydrophilicity, size, charge, shape, surface chemistry, and many other chemical and physical parameters, different types of cells in the central nervous system can be monitored, modulated, or further studies to elucidate underlying disease mechanisms. Scientists and clinicians have better understood the underlying processes of pathologies for many neurologically related diseases and injuries by implementing multi-dimensional 0D, 1D, and 2D theragnostic nanomaterials. The incorporation of nanomaterials has allowed scientists to better understand how to detect and treat these conditions at an early stage. To this end, having the multi-modal ability to both sense and treat ailments of the central nervous system can lead to favorable outcomes for patients suffering from such injuries and diseases.

miR-29b Regulates Lung Cancer Progression by Downregulating FEM1B and Inhibiting the FOX01/AKT Pathway

Purpose

Lung cancer is a relatively common type of cancer, and the incidence rate has been on the rise in recent years. MicroRNAs are a class of endogenous small RNA molecules, which are essential for the posttranscriptional regulation of genes. miR-29b is closely related to the occurrence and development of tumors, including prostate cancer, colon cancer, and breast cancer. However, few studies have been performed to explore the expression and pathway of miR-29b in non-small-cell lung cancer (NSCLC).

Methods

Using bioinformatics analysis, we found that patients with low relative expression of the miR-29b gene have a low long-term survival rate. The results of in vitro research showed that when miR-29b expression was upregulated, the invasion, migration, and proliferation of A549 and NCI-H-1792 cells was inhibited, and the apoptosis was accelerated.

Results

The results showed that FEM1B is a miR-29b target gene, and the expressions of FEM1B and miR-29b were negatively correlated. Like the upregulation of miR-29b expression, silencing the FEM1B expression could also impair the invasion, migration, and proliferation abilities of A549 and NCI-H-1792 cells. When FEM1B expression was restored, the inhibitory effect of miR-29b could be reversed. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot (WB) analysis showed that overexpression of miR-29b could inhibit the expression of FEM1B, AKT, vascular endothelial growth factor (VEGF), and Sirt3 in A549 and NCI-H-1792 cells and upregulate the expression of FOXO1 protein.

Conclusion

The results of this study indicate that miR-29b inhibits the proliferation and deterioration of NSCLC cells by targeting FEM1B and inhibiting the activation of the FOXO1/AKT pathway. miR-29b may become a new target for the clinical diagnosis and treatment of lung cancer, and it is expected to become a new inhibitor of NSCLC.

Knockdown of NANOG Reduces Cell Proliferation and Induces G0/G1 Cell Cycle Arrest in Human Adipose Stem Cells

The core components of regenerative medicine are stem cells with high self-renewal and tissue regeneration potentials. Adult stem cells can be obtained from many organs and tissues. NANOG, SOX2 and OCT4 represent the core regulatory network that suppresses differentiation-associated genes, maintaining the pluripotency of mesenchymal stem cells. The roles of NANOG in maintaining self-renewal and undifferentiated status of adult stem cells are still not perfectly established. In this study we define the effects of downregulation of NANOG in maintaining self-renewal and undifferentiated state in mesenchymal stem cells (MSCs) derived from subcutaneous adipose tissue (hASCs). hASCs were expanded and transfected in vitro with short hairpin Lentivirus targeting NANOG. Gene suppressions were achieved at both transcript and proteome levels. The effect of NANOG knockdown on proliferation after 10 passages and on the cell cycle was evaluated by proliferation assay, colony forming unit (CFU), qRT-PCR and cell cycle analysis by flow-cytometry. Moreover, NANOG involvement in differentiation ability was evaluated. We report that downregulation of NANOG revealed a decrease in the proliferation and differentiation rate, inducing cell cycle arrest by increasing p27/CDKN1B (Cyclin-dependent kinase inhibitor 1B) and p21/CDKN1A (Cyclin-dependent kinase inhibitor 1A) through p53 and regulate DLK1/PREF1. Furthermore, NANOG induced downregulation of DNMT1, a major DNA methyltransferase responsible for maintaining methylation status during DNA replication probably involved in cell cycle regulation. Our study confirms that NANOG regulates the complex transcription network of plasticity of the cells, inducing cell cycle arrest and reducing differentiation potential.

Inhibition of breast cancer metastasis by co-transfection of miR-31/193b-mimics

OBJECTIVES

Various studies have been conducted to reduce the metastatic behavior of cancerous cells. In this regard, ectopic expression of anti-metastatic microRNAs by miR-mimic and miR-restoration-based therapies could bring new insights to the field. In the present study, the consequences of co-transfecting breast cancer cell lines with miR-193b and miR-31 were investigated via invasion and migration assays.

MATERIALS AND METHODS

Double stranded oligonucleotide of mature miR-193b-3p and miR-31-5p were cloned into pcDNA 6.2gw/EmGFP plasmid. The resulting plasmids were used for transfection. Real time-PCR was performed to assess the expression of miR-193b and miR-31 as well as Ras homolog gene family member A (RhoA) and urokinase-type plasminogen activator (uPA) as miR targets. Scratch, Transwell migration and Matrigel invasion assays were carried out to assess the extent of migration and invasion of cell lines.

RESULTS

The most significant increase in expression of miRs belonged to the single transfection of mimic-miRs in MDA-MB231. Although the co-transfection was not as successful as single transfection in miR expression, it was significantly more effective in inhibition of the cells invasive potential.

CONCLUSION

Although the miR-restoration therapy based on co-transfection of two miRs could be less effective in expression of each miRNA, the resulting decrease in metastatic behavior of the cells is more significant due to collective effect of co-transfection to decrease target gene expression. Our results revealed that employing this sort of combinatorial strategies could lead to more efficient reduction in metastatic behavior. It seems that using this strategy would bring about more successful therapeutic outcomes.

Dual delivery of siRNA and plasmid DNA using mesoporous silica nanoparticles to differentiate induced pluripotent stem cells into dopaminergic neurons

Nurr1 plasmid and Rex1 siRNA were complexed with positively charged FITC-conjugated mesoporous silica nanoparticles. The pNurr1–siRex1–FMSN(+) was delivered to induced pluripotent stem cells to enhance their differentiation into dopaminergic neurons.

Basic Fibroblast Growth Factor Regulates REX1 Expression Via IL-6 In Stem Cells Isolated From Human Exfoliated Deciduous Teeth

Basic fibroblast growth factor (bFGF) regulates pluripotent marker expression and cellular differentiation in various cell types. However, the mechanism by which bFGF regulates REX1 expression in stem cells, isolated from human exfoliated deciduous teeth (SHEDs) remains unclear. The aim of the present study was to investigate the regulation of REX1 expression by bFGF in SHEDs. SHEDs were isolated and characterized. Their mRNA and protein expression levels were determined using real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. In some experiments, chemical inhibitors were added to the culture medium to impede specific signaling pathways. Cells isolated from human exfoliated deciduous tooth dental pulp tissue expressed mesenchymal stem cell surface markers (CD44, CD73, CD90, and CD105). These cells differentiated into osteogenic and adipogenic lineages, when appropriately induced. Treating SHEDs with bFGF induced REX1 mRNA expression and this effect was attenuated by pretreatment with FGFR or Akt inhibitors. Cycloheximide pretreatment also inhibited the bFGF-induced REX1 expression, implying the involvement of intermediate molecule(s). Further, the addition of an IL-6 neutralizing antibody attenuated the bFGF-induced REX1 expression by SHEDs. In conclusion, bFGF enhanced REX1 expression by SHEDs via the FGFR and Akt signaling pathways. Moreover, IL-6 participated in the bFGF-induced REX1 expression in SHEDs. J. Cell. Biochem. 118: 1480-1488, 2017. © 2016 Wiley Periodicals, Inc.

Cellular stage specific functional analysis of REX1: In human embryonic stem cells

As transcription and translation are dynamic and can vary among the cell types and conditions, proteomics may reveal the tissue-specific functions of a protein, more relevant to its genuine functions on cellular mechanisms. The new proteome analysis by Son et al. [Proteomics 2015, 15, 2220-2229] identified the functions of the pluripotency marker protein, REX1 in hESCs, and unraveling its regulatory network orchestrating pluripotency. Compared to the previous transcriptome analysis that showed mechanisms irrelevant to pluripotency, Son et al. employed a proteome analysis determined convincing and meaningful mechanisms of REX. In addition to demonstrating the biological importance of REX1, this research by Son et al. is also a compelling example of the conceptual significance of connecting proteomics with stem cell biology.

MiR-371-373 cluster acts as a tumor-suppressor-miR and promotes cell cycle arrest in unrestricted somatic stem cells

Recent advances in small RNA research have implicated microRNAs (miRNAs) as important regulators of proliferation and development. The miR-371-373 cluster is prominently expressed in human embryonic stem cells (ESCs) and rapidly decreases after cell differentiation. MiR-371-373 cluster was investigated as one of the key factors of stem cell maintenance and pluripotency in unrestricted somatic stem cells (USSCs) using a lentivirus system. Gene expression showed a dual effect on proliferation, which revealed a transient cell cycle progression and consequent repression in pluripotency factors and cell cycle genes. Cell proliferation analysis with CFU, MTT, and DNA content assays further confirmed the dual effect of cluster after prolonged exposure. Analyzing the course of action, it seems that miR-371-373 cluster acts as an onco/tumor suppressor-miR. MiR371-373 cluster acts by modulating the function of these factors and limiting the excessive cell cycle propagation upon oncogenic stimuli to protect cells from replicative stress, but also activate CDK inhibitors and transcriptional repressors of the retinoblastoma family to cause cell cycle arrest. In contrast to the previous studies, we believe that miR-371-373 cluster functions as a self-renewal miRNA to induce and maintain the pluripotent state but also to potentially inhibit dysregulated proliferation through cell cycle arrest. It seems that miR-371-373 cluster presents with a dual effect in this cellular context which may possess different actions in various cells. This not only expands the basic knowledge of the cluster but may offer a great chance for therapeutic interventions.