Study on the mechanism of imatinib-induced resistance in gastrointestinal stromal tumors / 中华肿瘤杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the mechanism of imatinib mesylate (IM) induced-resistance in the patients with gastrointestinal stromal tumors (GISTs) and treated with imatinib.</p><p><b>METHODS</b>Eight patients with GIST treated with IM developed secondary IM resistance. A total of 16 tumor samples (pre-IM therapy) and 11 tumor samples (post-IM treatment) were available. Exon 9, 11, 13, and 17 of c-kit gene as well as exon 12 and exon 18 of PDGFRA gene were sequenced.</p><p><b>RESULTS</b>In addition to the changes of baseline genotype, the IM-induced gene changes were concentrated in the kinase domain of c-kit gene in all 8 patients, 2 of them were located in the exon 13 of c-kit gene presenting with V654A, while 6 in exon 17 involving 816 and 820 to 823 codons.</p><p><b>CONCLUSION</b>The mechanism of imatinib mesylate resistance after initial treatment with this agent in gastrointestinal stromal tumors is a novel mutation development in kinase domain of c-kit.</p>