This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Guan, H. Articles by Kleinerman, E. S. PubMed PubMed Citation Articles by Guan, H. Articles by Kleinerman, E. S.

Research Articles: Therapeutics, Targets, and Development

Targeting Lyn inhibits tumor growth and metastasis in Ewing's sarcoma

¹ Division of Pediatrics and Departments of ² Cancer Biology and ³ Gynecologic Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas

Requests for reprints: Eugenie S. Kleinerman, Division of Pediatrics, The University of Texas M. D. Anderson Cancer Center, Unit 87, 1515 Holcombe Boulevard, Houston, TX 77030. Phone: 713-792-8110; Fax: 713-794-5042. E-mail: ekleiner{at}mdanderson.org

Abstract

Src family tyrosine kinases (SFK) play an important role in growth and metastasis of many types of human malignancies. However, their significance in Ewing's sarcoma remains to be elucidated. The purpose of this study was to evaluate the role of Lyn, one member of the SFK, in Ewing's sarcoma growth and metastasis and to determine whether a SFK inhibitor can induce Ewing's tumor regression. Lyn was expressed and activated in TC71, A4573, and SK-ES human Ewing's sarcoma cells. Lyn expression was seen in 13 of 15 patient tumor samples, 6 of which showed Lyn activation. Specific inhibition of Lyn using small interfering RNA significantly decreased primary tumor growth and lytic activity, and also reduced lung metastases in vivo. Down-regulation of Lyn resulted in decreased invasive capacity of tumor cells in vitro. AP23994, a small-molecule SFK inhibitor, decreased Lyn kinase activity and suppressed TC71 cell growth in vitro in a dose-dependent manner. Furthermore, treatment of mice bearing s.c. TC71 tumors with AP23994 or with polyethylenimine/Lyn-small interfering RNA gene therapy resulted in reduced Lyn kinase activity and significant tumor growth suppression. EWS/FLI-1, which is translocation fusion protein associated with Ewing's sarcoma, regulated Lyn gene expression and kinase activity. These data suggest that targeting Lyn may be a new therapeutic approach in treatment of Ewing's sarcoma. [Mol Cancer Ther 2008;7(7):1807–16]

Grant support: Kayton Fund, Lindner Fund, and NIH Core grant CA16672.

The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

Received 1/16/08; accepted 2/28/08.