Early effects of imatinib mesylate on the expression of insulin-like growth factor binding protein-3 and positron emission tomography in patients with gastrointestinal stromal tumor.

Journal Article

BACKGROUND: Imatinib has demonstrated marked clinical efficacy against gastrointestinal stromal tumor (GIST). Microarray technology, real-time polymerase chain reaction (PCR) validation, and fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging were used to study the early molecular effects of imatinib antitumor activity in GIST. METHODS: After exposure of sensitive and resistant sarcoma cell lines to imatinib for 24 to 48 hours, the changes in gene expression were evaluated using a 1146 unique pathway array with Western blot validation. Real-time PCR was used to confirm changes in gene expression in human GIST samples (preimatinib biopsy and postimatinib surgical specimen after 3-7 days of therapy). FDG-PET was performed to correlate radiographic findings with the effects of imatinib on gene expression in GIST. RESULTS: In all, 55 genes demonstrated a > or = 2-fold change after imatinib treatment of the GIST882 cells. Among these genes there was up-regulation of insulin-like growth factor binding protein-3 (IGFBP-3), a protein that modulates proliferation and apoptosis. Western blot analysis confirmed the increase of IGFBP-3 only in imatinib-sensitive GIST882 cells. Up to a 7-fold induction (49% mean increase; P = .08) of IGFBP-3 mRNA was found in tumor samples from patients with low residual FDG uptake, whereas there was an up to 12-fold reduction (-102% mean decrease; P = .03) in IGFBP-3 in those patients with high residual FDG uptake after imatinib therapy. CONCLUSIONS: In the current study, imatinib appears to regulate numerous genes and specifically induces IGFBP-3 in GIST cells and tumor samples. IGFBP-3 levels also were found to be inversely correlated with residual FDG uptake in GIST patients early in imatinib therapy. These initial observations suggest that IGFBP-3 is an important early marker of antitumor activity of imatinib in GIST.

Full Text

Duke Authors

Cited Authors

  • Trent, JC; Ramdas, L; Dupart, J; Hunt, K; Macapinlac, H; Taylor, E; Hu, L; Salvado, A; Abbruzzese, JL; Pollock, R; Benjamin, RS; Zhang, W

Published Date

  • October 2006

Published In

Volume / Issue

  • 107 / 8

Start / End Page

  • 1898 - 1908

PubMed ID

  • 16986125

Electronic International Standard Serial Number (EISSN)

  • 1097-0142

International Standard Serial Number (ISSN)

  • 0008-543X

Digital Object Identifier (DOI)

  • 10.1002/cncr.22214

Language

  • eng