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Gastrointestinal Stromal Tumors: From Molecular Pathogenesis to Therapy
Published in Sherry X. Yang, Janet E. Dancey, Handbook of Therapeutic Biomarkers in Cancer, 2021
Joaquina Baranda, Stafinur Atay, Andrew K. Godwin
Two additional studies have attempted to further characterize pediatric GISTs using expression profiling [88, 90]. In 2005 Prakash and colleagues performed gene expression analysis on seven gastric samples: five from two pediatric WT patients and two from different young adult patients (1 mutant, 1 WT) and compared these to 10 gastric adult GISTs (9 mutant, 1 WT). Although the sample sizes were small, the authors reported that all of the pediatric and young adult samples, with the exception of one pediatric sample, clustered together and were distinct from the adult GISTs, suggesting major molecular differences between these two GIST subsets. 385 genes were determined to be differentially expressed (> 2-fold change) between the two groups. Genes upregulated in the pediatric and young adult group included neuroligin 4 (NLGN4), ankyrin 3 (ANK3), frizzled 2 (FZD2), insulin-like growth factor receptor type 1 (IGF1R) and phosphorylase kinase alpha 1 (PHKA1). Genes that were significantly downregulated included dermatopontin (DPT), PDGFRA, RAS-family member, RAB38, and G-protein-coupled receptor 88 (GPR88). These results point to a possible genotype/phenotype correlation, since the pediatric/young adult group consisted of mostly WT tumors while the adult group consisted of mutant tumors.
The role of Thymosin β4 in angiotensin II-induced cardiomyocytes growth
Published in Expert Opinion on Biological Therapy, 2018
Our recent findings showed the efficacy of Tβ4 in Ang II-stimulated cardiomyocytes growth and the contribution of Wnt signaling cascade, particularly the WISP-1 [30]. Our data showed that Ang II increased the mRNA expression of Wnt signaling member proteins, which include Wnt-1, Wnt-3a, Frizzled 2 (Fz2), Dishevelled (Dvl)1, Dvl2 and the WISP-1. The cells treated with Tβ4 showed significant reduction in their expression indicating a new role of Tβ4 in Wnt signaling cascade (Figure 2(a)). Importantly, our data showed that Ang II stimulation stabilized β-catenin and upregulated the WISP-1 level and indicated a new role of WISP-1 in cardiac hypertrophy. The observation supports the previous findings where inhibition of β-catenin attenuated left ventricular remodeling [43,46]. The data may underscore a new role of Tβ4 in cardiac hypertrophy. To determine whether WISP-1 contributed a critical role in cardiac hypertrophy in vitro, our data demonstrated that overexpression of WISP-1 in cardiomyocytes enhances cell size along with hypertrophic marker gene expression (ANP, BNP, and β-MHC) (Figure 3). Cardiomyocytes treated with Tβ4 show a significant reduction in cell size and hypertrophy marker gene expression, indicating an antihypertrophic role of Tβ4 targeting WISP-1. The in vitro study suggests that Tβ4 targets WISP-1 in Ang II stimulated myocytes growth [30] . It is of note that the study was performed in cultured cardiomyocytes only and further study is needed in experimental in vivo model.
An RNAi-mediated screen identifies novel targets for next-generation antiepileptic drugs based on increased expression of the homeostatic regulator pumilio
Published in Journal of Neurogenetics, 2018
Wei-Hsiang Lin, Miaomiao He, Yuen Ngan Fan, Richard A. Baines
Insect S2 cells, derived from a primary culture of late stage (20–24 h old) Drosophila (Oregon-R) embryos (Schneider, 1972), are widely used to carry out large-scale functional screens (Boutros et al., 2004; Kleino et al., 2005; Ramet, Manfruelli, Pearson, Mathey-Prevot, & Ezekowitz, 2002). The S2R + subtype, used in this study, differs in the expression of the membrane receptor Drosophila frizzled 2 (Dfz2) (Yanagawa, Lee, & Ishimoto, 1998), making them more adherent than S2 cells and readily attach and spread to tissue culture plastic and glass. S2R + cells (1.5 × 104 cells in 15 μl of Schneider's Drosophila Medium, GibcoTM) were treated with 250 ng of double-stranded RNA (∼21,000 double-stranded RNAs, ∼98.8% coverage, covering ∼14,000 protein encoding genes and ∼1000 noncoding genes on 53 × 384 well plates) for 48 h, followed by co-transfection (Effectene®, QIAGEN) with firefly-PRE and renilla luciferase reporters (10 ng each) (Lin et al., 2017) for a further 48 h. The transfection procedure is as described in the manufacturer’s instructions (QIAGEN). S2R + cells were lysed with 0.35% TritonTM X-100 in BL buffer (50 mM HEPES, 0.5 mM EDTA, 0.36 mM phenylacetic acid and 0.07 mM oxalic acid) and D-Luciferin (0.46 mM, Molecular Probes) was added to measure firefly luciferase activity. This was followed by the addition of coelenterazine-h (3 mM, Promega) to measure renilla luciferase activity. A Varioskan® flash plate reader (Thermo Scientific) was used to measure luminescence.