Small RNA expression signatures of gastrointestinal stromal tumors: associations to imatinib resistance and patient outcome

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.