A key transcription factor associated with poor prognosis and resistance to chemotherapy in ovarian cancer is NANOG. However, the mechanism by which NANOG functions remains undefined. It has been ...suggested that epithelial-to-mesenchymal transition (EMT) also contributes to development of drug resistance in different cancers. We thus determined whether NANOG expression was associated with EMT and chemoresistance in epithelial ovarian cancer cells. NANOG expression was increased in epithelial ovarian cancer cell lines compared with its expression in normal epithelial ovarian cell lines. NANOG expression in SKOV-3 or OV2008 cells directly correlated with high expression of mesenchymal cell markers and inversely with low expression of epithelial cell marker. RNAi-mediated silencing of NANOG in SKOV-3 reversed the expression of mesenchymal cell markers and restored expression of E-cadherin. Reversibly, stable overexpression of NANOG in Moody cells increased expression of N-cadherin whereas down-regulating expression of E-cadherin, cumulatively indicating that NANOG plays an important role in maintaining the mesenchymal cell markers. Modulating NANOG expression did not have any effect on proliferation or colony formation. Susceptibility to cisplatin increased in SKOV-3 cells on down-regulating NANOG and reversible results were obtained in Moody cells post-overexpression of NANOG. NANOG silencing in SKOV-3 and OV2008 robustly attenuated in vitro migration and invasion. NANOG expression exhibited a biphasic pattern in patients with ovarian cancer and expression was directly correlated to chemoresistance retrospectively. Cumulatively, our data demonstrate that NANOG expression modulates chemosensitivity and EMT resistance in ovarian cancer.
NANOG, a stemness-associated transcription factor, is highly expressed in many cancers and plays a critical role in regulating tumorigenicity. Transformation/transcription domain-associated protein ...(TRRAP) has been reported to stimulate the tumorigenic potential of cancer cells and induce the gene transcription of NANOG. This study aimed to investigate the role of the TRRAP-NANOG signaling pathway in the tumorigenicity of cancer stem cells. We found that TRRAP overexpression specifically increases NANOG protein stability by interfering with NANOG ubiquitination mediated by FBXW8, an E3 ubiquitin ligase. Mapping of NANOG-binding sites using deletion mutants of TRRAP revealed that a domain of TRRAP (amino acids 1898-2400) is responsible for binding to NANOG and that the overexpression of this TRRAP domain abrogated the FBXW8-mediated ubiquitination of NANOG. TRRAP knockdown decreased the expression of CD44, a cancer stem cell marker, and increased the expression of P53, a tumor suppressor gene, in HCT-15 colon cancer cells. TRRAP depletion attenuated spheroid-forming ability and cisplatin resistance in HCT-15 cells, which could be rescued by NANOG overexpression. Furthermore, TRRAP knockdown significantly reduced tumor growth in a murine xenograft transplantation model, which could be reversed by NANOG overexpression. Together, these results suggest that TRRAP plays a pivotal role in the regulation of the tumorigenic potential of colon cancer cells by modulating NANOG protein stability.
Despite their rapidly-expanding therapeutic potential, human pluripotent stem cell (hPSC)-derived cell therapies continue to have serious safety risks. Transplantation of hPSC-derived cell ...populations into preclinical models has generated teratomas (tumors arising from undifferentiated hPSCs), unwanted tissues, and other types of adverse events. Mitigating these risks is important to increase the safety of such therapies. Here we use genome editing to engineer a general platform to improve the safety of future hPSC-derived cell transplantation therapies. Specifically, we develop hPSC lines bearing two drug-inducible safeguards, which have distinct functionalities and address separate safety concerns. In vitro administration of one small molecule depletes undifferentiated hPSCs >10
-fold, thus preventing teratoma formation in vivo. Administration of a second small molecule kills all hPSC-derived cell-types, thus providing an option to eliminate the entire hPSC-derived cell product in vivo if adverse events arise. These orthogonal safety switches address major safety concerns with pluripotent cell-derived therapies.
Pluripotency is a crucial feature of pluripotent stem cells, which are regulated by the core pluripotency network consisting of key transcription factors and signaling molecules. However, relatively ...less is known about the molecular mechanisms that modify the core pluripotency network. Here we used the CAPTURE (CRISPR Affinity Purification in situ of Regulatory Elements) to unbiasedly isolate proteins assembled on the
promoter in mouse embryonic stem cells (mESCs), and then tested their functional relevance to the maintenance of mESCs and reprogramming of somatic cells. Gene ontology analysis revealed that the identified proteins, including many RNA-binding proteins (RBPs), are enriched in RNA-related functions and gene expression. ChIP-qPCR experiments confirmed that BCLAF1, FUBP1, MSH6, PARK7, PSIP1, and THRAP3 occupy the
promoter region in mESCs. Knockdown experiments of these factors show that they play varying roles in self-renewal, pluripotency gene expression, and differentiation of mESCs as well as in the reprogramming of somatic cells. Our results show the utility of unbiased identification of chromatin-associated proteins on a pluripotency gene in mESCs and reveal the functional relevance of RBPs in ESC differentiation and somatic cell reprogramming.
Spermatogonial stem cells (SSCs) are defined as the tissue-specific stem cells in the testes that produce sperm and support life-long spermatogenesis. A culture microenvironment could convert mouse ...SSCs from unipotent to pluripotent states; however, the underlying mechanism is unclear. NANOG has been considered the decisive transcriptional factor for pluripotency transition of stem cells, but NANOG is not expressed in SSCs. Here, we investigated whether NANOG overexpression could result in SSCs being converted into a pluripotent state. We found that rare NANOG-positive cells could be detected in spermatogonia, pachytene spermatocytes, and even round spermatids in mouse testes, and that the induction of NANOG could promote the proliferation of cultured SSCs in vitro and partially compensate for the role of the growth factor GDNF. In vivo allogeneic transplantation of NANOG-overexpressing germ cells did not yield any teratoma-like tissues, but regenerated normal colonies of spermatogenesis in the testes of recipient mice. Collectively, our data showed that overexpression of the pluripotency factor NANOG along did not dedifferentiate testis germline stem cells into a pluripotent state, suggesting that other genetic or epigenetic factors are involved in SSC reprogramming.
•The mechanism of potency conversion between germline cells is not clear.•Overexpression of NANOG promotes the proliferation of mouse germ cells.•NANOG-induced germline stem cells showed spermatogenic properties by transplantation.•NANOG induction did not trigger the dedifferentiation of spermatogonia stem cells.
Transcription factor networks, together with histone modifications and signalling pathways, underlie the establishment and maintenance of gene regulatory architectures associated with the molecular ...identity of each cell type. However, how master transcription factors individually impact the epigenomic landscape and orchestrate the behaviour of regulatory networks under different environmental constraints is only partially understood. Here, we show that the transcription factor Nanog deploys multiple distinct mechanisms to enhance embryonic stem cell self-renewal. In the presence of LIF, which fosters self-renewal, Nanog rewires the pluripotency network by promoting chromatin accessibility and binding of other pluripotency factors to thousands of enhancers. In the absence of LIF, Nanog blocks differentiation by sustaining H3K27me3, a repressive histone mark, at developmental regulators. Among those, we show that the repression of Otx2 plays a preponderant role. Our results underscore the versatility of master transcription factors, such as Nanog, to globally influence gene regulation during developmental processes.
The transcription factor NANOG regulates self-renewal and pluripotency in embryonic cells, and its downregulation leads to cell differentiation. Recent studies have linked upregulation of
in various ...cancers and the regulation of expression of different molecules, and
, to induce proliferation, metastasis, invasion and chemoresistance. Thus
is an oncogene that functions by inducing stem cells’ circuitries and heterogeneity in cancers. Understanding NANOG’s role in various cancers may lead to it becoming a therapeutic target to halt cancer progression. The NANOG network can also be targeted to resensitize resistant cancer cells to conventional therapies. The current review focuses on NANOG regulation in the various signaling networks leading to cancer progression and chemoresistance, and highlights the therapeutic aspect of targeting NANOG in various cancers.
is a gene that is mainly expressed during development of the embryo. In adult tissues,
is hardly expressed. In embryonal cells, NANOG is responsible for generating stem cells. Once the cells are differentiated into their specific function, they no longer need this renewing property. So expression of NANOG in differentiated ‘adult’ cells is harmful as it helps tumor cells to grow.
expression also enables the tumor cells to keep on evolving their microenvironment, thus making it difficult for conventional therapy to destroy them. This review highlights the factors that influence NANOG’s expression in cancer progression and chemoresistance and how it can be targeted for therapy.
Zinc oxide (ZnO) nanoparticles (NPs) are generally utilized in cosmetic goods, sheds, biosensors, and delivery of drug. As in vitro ideal systems, mesenchymal stem cells (MSCs) are used to test acute ...toxicity. In the present study, size-dependent cytotoxicity effects of ZnO NPs on MSCs were assessed. Bone marrow and adipose MSCs were treated with ZnO NPs with average sizes of 10–30 and 35–45 nm. The 5 and 10 µg/ml concentrations of ZnO NP were found to be the safe concentrations for the NP sizes of 10–30 and 35–45 nm, respectively. Cell-cycle analysis indicated that the small size of ZnO NPs has more negative effects on the process of cell entry to DNA synthesis when compared to the larger size. The results of the β-galactosidase test showed the promotion of the aging process in the cells treated with the smaller size of ZnO NPs. Both sizes of the NP were found to upregulate the aging-related genes NF-kB and p53 and downregulate the anti-aging gene Nanog. To sum up, the smaller size of ZnO NPs can enhance the aging process in the cells.
ABSTRACT
Collagen type III (COL3) is one of the 3 major collagens in the body, and loss of expression or mutations in the COL3 gene have been associated with the onset of vascular diseases such the ...Ehlers‐Danlos syndrome. Previous work reported a significant reduction of COL3 in tissues such as skin and vessels with aging. In agreement, we found that COL3 was significantly reduced in senescent human mesenchymal stem cells and myofibroblasts derived from patients with Hutchinson‐Gilford progeria syndrome, a premature aging syndrome. Most notably, we discovered that ectopic expression of the embryonic transcription factor Nanog homeobox (NANOG) restored COL3 expression by restoring the activity of the TGF‐β pathway that was impaired in senescent cells. RNA sequencing analysis showed that genes associated with the activation of the TGF‐β pathway were up‐regulated, whereas negative regulators of the pathway were down‐regulated upon NANOG expression. Chromatin immunoprecipitation sequencing and immunoprecipitation experiments revealed that NANOG bound to the mothers against decapentaplegic (SMAD)2 and SMAD3 promoters, in agreement with increased expression and phosphorylation levels of both proteins. Using chemical inhibition, short hairpin RNA knockdown, and gain of function approaches, we established that both SMAD2 and SMAD3 were necessary to mediate the effects of NANOG, but SMAD3 overexpression was also sufficient for COL3 production. In summary, NANOG restored production of COL3, which was impaired by cellular aging, suggesting novel strategies to restore the impaired extracellular matrix production and biomechanical function of aged tissues, with potential implications for regenerative medicine and anti‐aging treatments.—Rong, N., Mistriotis, P., Wang, X., Tseropoulos, G., Rajabian, N., Zhang, Y., Wang, J., Liu, S., Andreadis, S. T. Restoring extracellular matrix synthesis in senescent stem cells. FASEB J. 33, 10954–10965 (2019). www.fasebj.org
Generating properly differentiated embryonic structures in vitro from pluripotent stem cells remains a challenge. Here we show that instruction of aggregates of mouse embryonic stem cells with an ...experimentally engineered morphogen signalling centre, that functions as an organizer, results in the development of embryo-like entities (embryoids). In situ hybridization, immunolabelling, cell tracking and transcriptomic analyses show that these embryoids form the three germ layers through a gastrulation process and that they exhibit a wide range of developmental structures, highly similar to neurula-stage mouse embryos. Embryoids are organized around an axial chordamesoderm, with a dorsal neural plate that displays histological properties similar to the murine embryo neuroepithelium and that folds into a neural tube patterned antero-posteriorly from the posterior midbrain to the tip of the tail. Lateral to the chordamesoderm, embryoids display somitic and intermediate mesoderm, with beating cardiac tissue anteriorly and formation of a vasculature network. Ventrally, embryoids differentiate a primitive gut tube, which is patterned both antero-posteriorly and dorso-ventrally. Altogether, embryoids provide an in vitro model of mammalian embryo that displays extensive development of germ layer derivatives and that promises to be a powerful tool for in vitro studies and disease modelling.
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