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: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) Keywords: other
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:Prognosis in Gastrointestinal Stromal Tumors (GIST) depends on clinical and pathological parameters that may be little objective, thus it is necessary to have other molecular biomarkers in the management of the disease.
Project description:To analyze the gene expression signatures in gastrointestinal stromal tumors (GISTs), a series of 14 GIST specimens were analyzed using Agilent Whole Human Genome Microarray (4x44K, G4112F).
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.
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:To reveal mechanisms for acquired imatinib resistance in gastrointestinal stromal tumor (GIST), we have analyzed several cell lines with resistance to imatinib.
Project description:We performed microRNA expression profiling in a series of fresh-frozen neoadjuvantly imatinib-treated and non-treated gastrointestinal stromal tumors (GIST), using a microarray approach. Significant differentially expressed microRNAs among imatinib-treated and non-treated groups were identified using SAM analysis.
Project description:Activating mutations in the KIT or PDGFRA receptor tyrosine kinases are hallmarks of gastrointestinal stromal tumor (GIST). The biological underpinnings of recurrence following resection or disease progression beyond kinase mutation are poorly understood. Utilizing chromatin immunoprecipitation with sequencing (ChIP-seq) of tumor samples and cell lines, we describe the enhancer landscape of GIST, highlighting genes that reinforce and extend our understanding of these neoplasms. A group of core transcription factors can be distinguished from others unique to localized and metastatic disease. The transcription factor HAND1 emerges in metastatic disease, binds to established GIST-associated enhancers and is required for GIST cell proliferation and KIT gene expression. The pattern of transcription factor expression in primary tumors is predictive of metastasis-free survival in GIST patients. These results provide insight into the enhancer landscape and transcription factor network underlying GIST, and define a new strategy for predicting clinical behavior of this disease.