Human schwannomas express activated platelet-derived growth factor receptors and c-kit and are growth inhibited by Gleevec (Imatinib Mesylate).

Abstract

Schwannomas, although benign, can be fatal or give rise to significant morbidity due to an unpredictable growth rate. They can reoccur after surgery or radiation, current treatments each with significant inherent risks. These risks are further amplified in neurofibromatosis type 2 (NF2), a germ line predisposition syndrome characterized by multiple schwannomas, underlying the need for biological targeted therapies. Gleevec (STI571, imatinib mesylate), in addition to the bcr-abl oncogene in chronic myelogenous leukemia, inhibits c-kit and platelet-derived growth factor receptor (PDGFR) signaling, thereby expanding its use to several malignant and benign human diseases. In the present study, we show that human sporadic and NF2-associated schwannomas have increased expression along with activation of PDGFR-alpha, PDGFR-beta, and c-kit receptors, compared with normal or traumatic nerve. Using the human NF2-null HEI-193 schwannoma cell line, Gleevec inhibited schwannoma viability, proliferation, and anchorage-independent growth, as well as induced apoptosis in a dose-dependent manner (IC(50) 5-10 micromol/L). These antitumorigenic effects were correlated to inhibition of PDGFR-alpha, PDGFR-beta, and c-kit activation/phosphorylation and major downstream signaling pathways. Lack of robust xenograft or transgenic models of schwannomas prevents extension of these studies in vivo. However, the established long track record and tolerable toxicity of Gleevec already in clinical use and our preclinical data lead us to propose that Gleevec should be evaluated in human schwannomas with shown progressive growth.

• Authors: Joydeep Mukherjee, Deepak Kamnasaran, Anand Balasubramaniam, Ivan Radovanovic, Gelareh Zadeh, Tim-Rasmus Kiehl, Abhijit Guha
• Journal: Cancer research (Cancer Res) Vol. 69 Issue 12 Pg. 5099-107 (Jun 15 2009) ISSN: 1538-7445 [Electronic] United States
• PMID: 19509233 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antineoplastic Agents
• Benzamides
• Piperazines
• Pyrimidines
• Imatinib Mesylate
• Proto-Oncogene Proteins c-kit
• Receptors, Platelet-Derived Growth Factor

Topics

• Antineoplastic Agents (pharmacology)
• Apoptosis
• Benzamides
• Blotting, Western
• Cell Cycle
• Cell Division (drug effects)
• Cell Line, Tumor
• Humans
• Imatinib Mesylate
• Magnetic Resonance Imaging
• Neurilemmoma (metabolism, pathology)
• Piperazines (pharmacology)
• Polymerase Chain Reaction
• Proto-Oncogene Proteins c-kit (metabolism)
• Pyrimidines (pharmacology)
• Receptors, Platelet-Derived Growth Factor (metabolism)