Project description:Silencing of the adaptor SH3BP2 impairs Gastrointestinal stromal tumors growth through miRNAs We dissected SH3BP2 pathway in Gastrointestinal Stromal Tumor cells (GIST) performing a miRNA array in SH3BP2-silenced GIST cells
Project description:Gastrointestinal stromal tumors (GISTs) are the most important mesenchymal tumors of the gastrointestinal tract. The vast majority of GISTs exhibit activating mutations of KIT or PDGFRA, but epigenetic alteration of GISTs is largely unknown. In this study, we aimed to clarify the involvement of DNA methylation in GIST malignancy. A total of 25 GIST specimens were studied using Human Genome CGH Microarray Kit 105A (G4412A, Agilent). Levels of LINE-1 methylation were analyzed using bisulfite-pyrosequencing. LINE-1 hypomethylation was correlated with risk grade, and high-risk GISTs exhibited lower levels of LINE-1 methylation than low- or intermediate-risk GISTs. Array CGH analysis revealed a significant correlation between LINE-1 hypomethylation and chromosomal aberrations. Our data suggest that LINE-1 hypomethylation correlates with the aggressiveness of GISTs. Hypomethylation may increase the malignant potential of GISTs by inducing accumulation of chromosomal aberrations. A total of 25 surgically obtained human gastrointestinal stromal tumors (GISTs) was analyzed using Agilent CGH microarray. Copy number aberration was compared with clinicopathological features and DNA methylation status.
Project description:Gastrointestinal stromal tumors (GISTs) are the most important mesenchymal tumors of the gastrointestinal tract. The vast majority of GISTs exhibit activating mutations of KIT or PDGFRA, but epigenetic alteration of GISTs is largely unknown. In this study, we aimed to clarify the involvement of DNA methylation in GIST malignancy. A total of 25 GIST specimens were studied using Human Genome CGH Microarray Kit 105A (G4412A, Agilent). Levels of LINE-1 methylation were analyzed using bisulfite-pyrosequencing. LINE-1 hypomethylation was correlated with risk grade, and high-risk GISTs exhibited lower levels of LINE-1 methylation than low- or intermediate-risk GISTs. Array CGH analysis revealed a significant correlation between LINE-1 hypomethylation and chromosomal aberrations. Our data suggest that LINE-1 hypomethylation correlates with the aggressiveness of GISTs. Hypomethylation may increase the malignant potential of GISTs by inducing accumulation of chromosomal aberrations.
Project description:To determine the circRNA expression profile in gastrointestinal stromal tumor and matched non-tumor tissues, we used circRNA microArray analysis from Arraystar to examine the expression of circRNAs in gastrointestinal stromal tumor and matched non-tumor tissues.
Project description:Gastrointestinal stromal tumors (GISTs) have an impaired gene expression. As microRNAs (miRNAs) are involved in post-transcriptional regulation of gene expression we performed the first high-throughput miRNA profiling of 15 paired GIST formalin-fixed and paraffin-embedded samples (tumor and adjacent normal tissue) using small RNA sequencing approach.
Project description:siRNA knock-down of ZNF genes determined to impact gastrointestinal stromal tumor response to imatinib were used to determine functional significance of ZNFs and identify key targets related to imatinib resistance. exploratory array design to identify candidate effector genes for targeted study
Project description:To clarify the microRNA (miRNA) expression signatures in gastrointestinal stromal tumors (GISTs), a series of 32 GIST specimens were analyzed using Agilent miRNA microarray V3. Unsupervised hierarchical clustering revealed that GISTs can be categorized into 2 groups according to the expression of a miRNA cluster encoded on chromosome 14q32.31. Total RNA was extracted from 32 fresh frozen GIST specimens obtained from surgical resections. Expression of 851 miRNAs was analyzed using Human miRNA Microarray V3 (Rel 12.0 G4470C; Agilent technologies, Santa Clara, CA, USA). Risk grade was assessed according to the risk definition system proposed by Fletcher et al. (Hum Pathol. 2002;33:459-65.)
Project description:Gastrointestinal stromal tumors (GIST) are phenotypically and clinically heterogeneous mesenchymal tumors. Using the cDNA array technique, we analyzed the gene expression profiles of 22 GIST and 7 non-neoplastic gastrointestinal smooth muscle specimens, in order to detect molecular differences between GIST and non-neoplastic tissue, and to detect differences between GIST of various phenotypic and clinical subgroups. As a result, we found 796 differentially expressed genes and ESTs between GIST and smooth muscle tissue, including promising new candidate genes for the pathogenesis of GIST. Furthermore, we identified differences in gene expression between GIST of different site, size, and immunohistochemical expression of CD34 and SMA. Our data show that alterations in gene expression are associated with morphologically and clinically detectable features of GIST and provide new aspects for the understanding of these tumors. Keywords = Gastrointestinal Stromal Tumor (GIST)
Project description:We performed miRNA expression profiling in a series of fresh-frozen neoadjuvantly imatinib treated gastrointestinal stromal tumors (GIST), using a microarray approach. Significant differentially expressed miRNAs among imatinib-resistant and imatinib-sensitive groups were identified using SAM analysis. Agilent microarray platform with probes matching 903 human miRNAs was used to determine miRNA expression profiles in 17 GISTs (imatinib-sensitive and 7 imatinib-resistant). To validate the microarray platform, the expression levels of selected miRNAs were evaluated using qRT-PCR.