Project description:To understand the contribution of germline DNA polymorphisms discriminating between imatinib clinical outcome and toxicity, 38 GIST patients (all with KIT exon 11 mutation) treated with imatinib were analyzed through Affymetrix human DMET Plus array.
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:The gene expression profile of TAMs sorted from vehicle control tumors in GIST mice (Sommer et al, PNAS 2003) was compared to TAMs sorted from mice after 2 weeks of imatinib therapy The Affymetrix Mouse Genome 430A 2.0 platform was used
Project description:Purpose: The goals of this study are to characterize the transcriptional dysregulation of GIST. More importantly, the transcriptome differences betweeen Imatinib-sensitive and resistant patients are compared to identify RNAs that may impact Imatinib resistance. Methods: High-throughput RNA sequencing (RNA-seq) was employed to capture the transcriptional changes in GIST compared to normal samples. RSEM was used to quantify gene expression and DESeq2 was utilized to compared expression changes between different sample groups.
Project description:The gene expression profile of TAMs sorted from vehicle control tumors in GIST mice (Sommer et al, PNAS 2003) was compared to TAMs sorted from mice after 2 weeks of imatinib therapy The Affymetrix Mouse Genome 430A 2.0 platform was used Each treatment group had 8 mice. After 2 weeks of treatment, mice were sacrificed and tumors digested with collagenase. TAMs were then FACS sorted and pooled by group. Pooled groups were run in duplicate for the gene expression array.
Project description:Activating mutations in either KIT or PDGFRA are present in approximately 90% of gastrointestinal stromal tumors (GISTs). Although treatment with the KIT and PDGFR inhibitor imatinib can control advanced disease in about 80% of GIST patients, the beneficial effect is not durable. Here, we report that ligands from the FGF family reduced the effectiveness of imatinib in GIST cells, and FGF2 and FGFR1 are highly expressed in all primary GIST samples examined. The combination of KIT and FGFR inhibition showed increased growth inhibition in imatinib-sensitive GIST cell lines in the presence or absence of added FGF2 in vitro, and delayed tumor regrowth in vivo. In addition, inhibition of mitogen-activated protein kinase (MAPK) signaling by imatinib was not sustained in GIST cells. An extracellular signal-regulated kinase (ERK) rebound occurred through activation of FGF signaling, and was repressed by FGFR1 inhibition. Downregultation of Sprouty proteins played a role in the imatinib-induced feedback activation of FGF signaling in GIST cells. We used micorarrays to quantify the gene expression levels in GIST cell lines. Four GIST cell lines were split and cultured overnight. Cells were harvested for RNA extraction and hybridization on Affymetrix U133plus2 microarrays.
Project description:Activating mutations in either KIT or PDGFRA are present in approximately 90% of gastrointestinal stromal tumors (GISTs). Although treatment with the KIT and PDGFR inhibitor imatinib can control advanced disease in about 80% of GIST patients, the beneficial effect is not durable. Here, we report that ligands from the FGF family reduced the effectiveness of imatinib in GIST cells, and FGF2 and FGFR1 are highly expressed in all primary GIST samples examined. The combination of KIT and FGFR inhibition showed increased growth inhibition in imatinib-sensitive GIST cell lines in the presence or absence of added FGF2 in vitro, and delayed tumor regrowth in vivo. In addition, inhibition of mitogen-activated protein kinase (MAPK) signaling by imatinib was not sustained in GIST cells. An extracellular signal-regulated kinase (ERK) rebound occurred through activation of FGF signaling, and was repressed by FGFR1 inhibition. Downregultation of Sprouty proteins played a role in the imatinib-induced feedback activation of FGF signaling in GIST cells. We used micorarrays to quantify the gene expression levels in GIST cell lines.
Project description:Gastrointestinal Stromal Tumor frequently harbor mutations in the KIT receptor tyrosine kinase and depend on its activity for growth. This underlies the efficacy of imatinib, a inhibitor of KIT activity, in GIST management. GIST882 is a patient derived GIST cell line that harbor a K640E exon 13 KIT mutation and is sensitive to imatinib treatment. To analyze the downstream effect of KIT inhibition, GIST882 cells were treated for 8 hours with 1μM Imatinib.
Project description:Analysis of mouse GIST tumors at the gene expression level. The purpose of the study was to identify immunomodulatory genes in mouse GIST tumors after in vivo treatment with the specific tyrosine kinase inhibitor imatinib mesylate. Total RNA obtained from mouse GIST tumors after in vivo treatment with imatinib or vehicle control injected intraperitoneally.
Project description:Analysis of mouse GIST tumors at the gene expression level. The purpose of the study was to identify immunomodulatory genes in mouse GIST tumors after in vivo treatment with the specific tyrosine kinase inhibitor imatinib mesylate.