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Introduction to regenerative engineering and developmental biology
Published in David M. Gardiner, Regenerative Engineering and Developmental Biology, 2017
The paradigm shift in realizing that the genetic pathways controlling development are conserved was triggered largely by the discovery of the homeobox genes. Based on early studies of homeotic transformations in which one body part develops in the place of another (e.g., the antennapedia mutation in Drosophila), the sequencing of mRNA identified a highly conserved DNA-binding sequence, the homeodomain (Duboule and Dollé 1989; De Robertis et al. 1990; Gehring 1993). With the sequencing of more genes, it quickly became evident that the homeodomain is highly conserved among a family of related genes (the Hox complex), and that highly conserved homologous genes are present in all animals. What now is a fundamental concept of developmental biology was revolutionary at that time and led quickly to the discovery that gene function and sequence are conserved. Thus, homologous mammalian genes could substitute for the function of Drosophila genes. Today, it is recognized that gene regulatory networks and signaling pathways are conserved between species, and are reutilized multiple times at different developmental stages to make an embryo (Gilbert 2013).
Glossary of scientific and technical terms in bioengineering and biological engineering
Published in Megh R. Goyal, Scientific and Technical Terms in Bioengineering and Biological Engineering, 2018
Homeobox is a highly conserved 180 bp DNA sequence that controls body part-, organor tissuespecific gene expression, most particularly involved in segmentation in animals, but also in a variety of other eukaryotes.
Effects of tobacco compound 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) on the expression of epigenetically regulated genes in lung carcinogenesis
Published in Journal of Toxicology and Environmental Health, Part A, 2021
Sun Woo Jin, Jong Seung Im, Jae Hyeon Park, Hyung Gyun Kim, Gi Ho Lee, Se Jong Kim, Seung Jun Kwack, Kyu-Bong Kim, Kyu Hyuck Chung, Byung Mu Lee, Sam Kacew, Hye Gwang Jeong, Hyung Sik Kim
Cdx1 is a homeobox protein that inhibits the proliferation of intestinal epithelial cells and regulates intestine-specific genes involved in differentiation (Silberg et al. 2000). CDX1 gene expression is developmentally and spatially regulated with its expression aberrantly downregulated in colorectal cancer and colon cancer-derived cell lines (Suh et al. 2002). However, little is known regarding molecular mechanisms underlying the epigenetic regulation of CDX1 expression in carcinogenesis. In the present study, the epigenetically regulated CDX1 gene in promoter DNA methylation containing a typical CpG island was decreased, suggesting that the CDX1 gene is a target for aberrant methylation. Based upon these findings, it was postulated that CDX1 inhibits epithelial proliferation in the lung tissues of mice following nasal cavity exposure to NNK.
Down-regulation of pluripotency and expression of SSEA-3 surface marker for mesenchymal Muse cells by in vitro expansion passaging
Published in Egyptian Journal of Basic and Applied Sciences, 2019
Ali M. Fouad, Mahmoud M. Gabr, Elsayed K. Abdelhady, Sahar A. Rashed, Sherry M. Khater, Mahmoud M. Zakaria
Total RNA was extracted from all passages by Direct-Zol RNATM Mini Prep kit (ZYMORESEARCH, USA). Three micrograms of total RNA was converted by RT2 First Standard Kit (Qiagen, Germany) to cDNA. Gene expression was evaluated for pluripotent genes; Nanog Homeobox (Nanog), SRY-box2 (Sox2), and POU Class 5 Homeobox 1 (POU5F1 or OCT-4) as referred in Table 1. MSCs gene expression for targeted genes served as control and for mathematical calculations. Glyceraldehyde-3-Phosphate Dehydrogenase (GAPDH) was included as a reference gene and for normalization the results. Amplifications were performed in a total 25 µL reaction volume in each well that contains 12.5 µL 2X SYBR Green Rox Master Mix (Qiagen), 100 ng of cDNA template, 10 pmol primers and nuclease-free water. The plate array was inserted in CFX96 real-time system (Bio-Rad, USA) and programmed according to manufacturer instructions by using the cycling parameters of the PCR amplification as follows: initial denaturation at 95ºC for 3 min, followed by 40 cycles of amplification (denaturation at 94°C for 10 s, annealing and extension at 60°C for 30 s). For each sample, the procedure was carried out in triplicate. A mathematical model introduced by M. Pfaffl was used for the relative quantification of target genes [10].
Understanding the complex microenvironment in oral cancer: the contribution of the Faculty of Dentistry, University of Otago over the last 100 years
Published in Journal of the Royal Society of New Zealand, 2020
Alison Mary Rich, Haizal Mohd Hussaini, Benedict Seo, Rosnah Bt Zain
A typical feature of neoplasia is the secretion of angiogenic factors via a complex balance of pro- and anti-angiogenic mechanisms (Folkman and Shing 1992). It is known that endothelial cells in the TME participate in cross talk with tumour cells themselves and promote invasion. In a study in our laboratory angiogenic factors (vascular endothelial growth factor [VEGF], VEGF receptor 2 [KDR] and vasohibin-1 [VASH-1]) were expressed differently in the endothelial cells and the epithelial cells of inflamed hyperplastic oral tissues compared with OSCC and normal oral mucosa (NOM) (Allsobrook 2014). The malignant keratinocytes of OSCC were strongly VEGF+. Gene expression in three immortal OSCC cell lines (SCC4, SCC15 and SCC25) and three normal epithelial cell lines (OKF4, OKF6 and OKP7) showed differential regulation of VEGF in OSCC compared with normal epithelial cells (Allsobrook 2014). Likewise, lymphangiogenesis is a key component of carcinogenesis with loss of control of lymphangiogenic regulation leading to the formation of new lymph vessels within and around the tumour. This may increase the likelihood of lymphatic metastasis. Using IHC with reliable lymphatic endothelial cell (LEC) antibody markers, we were able to establish that the OSCC TME possessed significantly more lymphatic vessels expressing D2-40 (Figure 6) podoplanin (D2-40) and prospero-homeobox protein (Prox)-1 than the control groups (Chutipongpisit 2016). Overexpression of the lymphatic markers in the malignant tissues was significantly greater than in the inflamed connective tissue as well as the normal controls, i.e. increased lymphangiogenesis associated with non-specific inflammation was controlled for. This increase in lymphatic vessels density (LVD) may play a role in facilitating lymphatic invasion and later metastases. These molecular entities may serve as potential anti-oral cancer therapeutic targets. D2-40 expression on the tumour cells themselves has been associated with a role in tumour progression in experimental and human carcinogenesis (Schacht et al. 2005; Ugorski et al. 2016) including in oral cancer (Martin-Villar et al. 2005; Yuan et al. 2006; Cueni et al. 2010; Tsuneki et al. 2013) and OPMD (Kawaguchi et al. 2008; Mei et al. 2014). In OPMD, the basal cell layer of the dysplastic epithelium was D2-40+ (Kawaguchi et al. 2008), a phenomenon also observed in our study in dysplastic epithelium adjacent to OSCC (Chutipongpisit 2016). Multivariate analysis found that epithelial D2-40 positivity was an independent predictor of progression of OPMD to OSCC and that it can be used to further stratify oral cancer development risk (Kawaguchi et al. 2008).