Differential transcriptional regulation of the NANOG gene in chicken primordial germ cells and embryonic stem cells.

BACKGROUND: NANOG is a core transcription factor (TF) in embryonic stem cells (ESCs) and primordial germ cells (PGCs). Regulation of the NANOG gene by TFs, epigenetic factors, and autoregulatory factors is well characterized in ESCs, and transcriptional regulation of NANOG is well established in these cells. Although NANOG plays a key role in germ cells, the molecular mechanism underlying its transcriptional regulation in PGCs has not been studied. Therefore, we investigated the mechanism that regulates transcription of the chicken NANOG (cNANOG) gene in PGCs and ESCs. RESULTS: We first identified the transcription start site of cNANOG by 5'-rapid amplification of cDNA ends PCR analysis. Then, we measured the promoter activity of various 5' flanking regions of cNANOG in chicken PGCs and ESCs using the luciferase reporter assay. cNANOG expression required transcriptional regulatory elements, which were positively regulated by POU5F3 (OCT4) and SOX2 and negatively regulated by TP53 in PGCs. The proximal region of the cNANOG promoter contains a positive transcriptional regulatory element (CCAAT/enhancer-binding protein (CEBP)-binding site) in ESCs. Furthermore, small interfering RNA-mediated knockdown demonstrated that POU5F3, SOX2, and CEBP played a role in cell type-specific transcription of cNANOG. CONCLUSIONS: We show for the first time that different trans-regulatory elements control transcription of cNANOG in a cell type-specific manner. This finding might help to elucidate the mechanism that regulates cNANOG expression in PGCs and ESCs.

Long non-coding RNA-H19 promotes proliferation and migration of non-small cell lung cancer cells through sponging microRNA-760 to regulate nanog gene expression / 第二军医大学学报

ObjectiveTo explore the role of long non-coding RNA (lncRNA)-H19 in the proliferation and migration of non-small cell lung cancer (NSCLC) cells and the molecular mechanisms. MethodsThe expressions of lncRNA-H19 in 20 NSCLC tissues and paired non-tumor tissues, which were collected from Changhai Hospital of Naval Medical University (Second Military Medical University) from Oct. 2015 to May 2016, were detected by real-time quantitative PCR (qPCR). We also examined lncRNA-H19 expressions in NSCLC cell lines A549 and NCI-H1299 and normal lung epithelial cell line BEAS-2B by qPCR. The proliferation and migration of A549 cells overexpressing lncRNA-H19 were detected by CCK-8 assay and Transwell assay, respectively. Bioinformatics analysis and duel-luciferase reporter assay were conducted to predict and confirm the interaction between microRNA (miRNA)-760 and lncRNA-H19. Western blotting analysis and RT-qPCR were performed to observe the influence of lncRNA-H19 overexpression on the expression of miRNA-760 and target gene nanog. MiRNA-760 was overexpressed in A549 cells, and its role in lncRNA-H19 promoting proliferation and migration of NSCLC cells was observed. Results The expressions of lncRNA-H19 in NSCLC tissues and A549 and NCI-H1299 cells were significantly upregulated compared with those in normal tissues and BEAS-2B cells (all P<0.01). Overexpression of lncRNA-H19 significantly improved the proliferation ability (P<0.05) and migration ability (P<0.01) of A549 cells compared with the negative control group. The results of starBase v3.0 showed that lncRNA-H19 could specifically adsorb miRNA-760, and duel-luciferase reporter assay showed that lncRNA-H19 directly bound to miRNA-760. Compared with the negative control group, overexpression of lncRNA-H19 significantly inhibited miRNA-760 expression in A549 cells (P<0.05) and promoted the expression of the downstream gene nanog at mRNA and protein levels (all P<0.01). Overexpression of miRNA-760 significantly inhibited lncRNA-H19-induced proliferation and migration of A549 cells (all P <0.05). ConclusionLncRNA-H19 can promote the proliferation and migration of NSCLC cells through sponging miRNA-760 to regulate nanog gene expression.

Significance of stem cell marker Nanog gene in the diagnosis and prognosis of lung cancer.

The aim of the present study was to analyze the stem cell marker, Nanog gene, for the diagnosis and prognosis of lung cancer cases, and to study its application in the diagnosis of lung cancer. In total, 100 patients diagnosed with lung cancer between April, 2013 and May, 2015 were included in the present study. The patients were randomly divided into group A (lung cancer) and group B (squamous cell lung carcinoma). RT-PCR was used to detect the cancer and adjacent tissues, and Nanog gene expression was detected in groups A and B in cells. The results showed that, analysis of Nanog gene expression in the two groups of patients varied to different degrees. There was no significant difference between the two groups with regard to age, gender, disease stage and lymph node metastasis. Nanog gene expression in patients with carcinoma were significantly higher than that in the adjacent tissues (p<0.05). By contrast, differentiated and well-differentiated carcinoma tissue showed a significantly higher Nanog gene expression than poorly differentiated and undifferentiated carcinoma (p<0.05). The expression of Nanog in normal cells was significantly higher than that in normal lung tissues and benign lesions in lung cancer stem cells. Nanog was highly expressed in CD44+ cells, and Nanog expression in lung cancer stem cells was significantly higher (p<0.05). In conclusion, for groups A (lung cancer) and B (squamous cell lung carcinoma) the Nanog gene expression was significantly higher. The data of the present study show that the patients with stage III and IV lung cancer had a higher Nanog gene expression. In addition, there was a higher expression of Nanog in lung cancer patients. By contrast, a lower degree of cell differentiation was associated with strong Nanog gene expression in lung cancer.

The synergistic effect of 5Azadc and TSA on maintenance of pluripotency of chicken ESCs by overexpression of NANOG gene.

NANOG is a transcription factor that functions in embryonic stem cells (ESCs) and a key factor in maintaining pluripotency. Here, we cloned the NANOG gene promoter from the Rugao yellow chicken and constructed a dual luciferase reporter vector to detect its transcriptional activity and analyze the effects of 5-aza-2'-deoxycytidine (5-Azadc) and trichostatin A (TSA) on NANOG promoter activity and ESC pluripotency maintenance in vitro. NANOG transcriptional activity was enhanced when 5-Azadc and TSA were used alone or together, suggesting the possibility of elevated methylation of the CpG island in the NANOG regulatory region. When ESCs were cultured in basic medium with 5-Azadc and TSA in vitro, significantly more cell colonies were maintained in the 5-Azadc + TSA group than in the control group, which had many differentiated cells and few cell colonies after 6 d of induction. On the tenth day of induction, the cells in the control group fully differentiated and no cell colonies remained, but many cell colonies were present in the 5-Azadc + TSA group. The expression of NANOG in the cell colonies was confirmed by indirect immunofluorescence. Furthermore, ESCs could be passaged to the 12th generation under 5-Azadc and TSA treatment and maintained their pluripotency. Thus, we showed that 5-Azadc and TSA can effectively maintain chicken ESC pluripotency in vitro by increasing NANOG gene expression.

Expression of NANOG gene in cervical cancer and its significance / 西安交通大学学报(医学版)

Objective To investigate the expression of NANOG gene in cervical cancer and its effect on the development of the cancer. Methods By using immunohistochemistry, NANOG expression levels were demonstrated in normal cervical tissues, cervical cancer in situ and cervical cancer tissues. Tumor sphere cells from cervical cancer tissue and their differentiated cells were injected into nude mice to observe the tumor growth. Results When compared with that of the normal cervical tissue, significantly higher NANOG protein expression level was found in cervical cancer and cervical cancer in situ (P<0.05). Tumor spheres were formed from the non-serum culture of cervical cancer tissue and the spheres could differentiate into epithelial-like cells. The sphere cells of cervical cancer caused tumor formation in nude mice. Conclusion The results suggest that cancer stem cells are present in cervical cancer and NANOG may play a crucial role in the development of cervical cancer.

Células madre: generalidades, eventos biológicos y moleculares / Stem cells: general aspects, biological and molecular events

Las autorrenovación y la diferenciación son características de las células madre que varían entre los diferentes tipos celulares según el tejido en el que se encuentren y el microambiente que las rodee. En ambos procesos intervienen inhibidores del ciclo celular, genes implicados en rearreglos cromosómicos, proteínas del desarrollo esencial y vías de señalización específicas. La autorrenovación está regulada por diversos mecanismos, entre los cuales se destacan las vías Wnt, Notch y Hedgehog, y los factores BMI-1, p16Ink4a, ARF, NANOG, OCT3/4, SOX2, HOXB4 y sus páralogos. Los adelantos en el conocimiento de la biología de las células madre y de los mecanismos moleculares que regulan la autorrenovación y la diferenciación han convertido a estas células en una importante promesa para la investigación básica y aplicada.

Self-renewal capacity and differentiation are features of stem cells that vary among the different cellular types according to the tissue in which they reside and the surroundingmicroenvironment. Cellular cycle inhibitors, genes implied in chromosomal rearrangements, essential development proteins and specific signaling pathways intervene in these processes. Self-renewal is regulated by different mechanisms, the most important of which are the Wnt, Notch and Hedgehogpathways, and the factors BMI-1, p16Ink4a, ARF, NANOG, OCT3/4, SOX2, HOXB4 and their paralogs. Advancesin the knowledge of stem cells biology and of the molecular mechanisms that influence their selfrenewal and differentiation have made these cellsan important promise for both basic and applied research.

Expression of Nanog Gene with the Mediation of Ientiviral Vector in Mouse ES Cells / 中国生物工程杂志

In order to further study mouse embryonic stem cells(ES cells),lentiviral vector PLL-IRES-Nanog-Neo was constructed.Mouse ES cells overexpressed nanog by mediation of lentiviral were cultured on mouse fetal fibroblast feeders after 2 weeks under G418 media and examined according to gowth characteristics. Results were showed that 918 bp nanog fragments were expressed in mouse ES cells mediated by lentiviral vector PLL-IRES-Nanog-Neo,mouse nanog-ES cells were taken on mass-like image and positve with alkaline phosphatase staining and Oct4 and SSEA1 immunocytochemistry under no LIF condition in the media. It is concluded that mouse ES cells Elevated nanog gene expression by mediation of lentiviral were constucted and cultured.