RNA aptamer blockade of osteopontin inhibits growth and metastasis of MDA-MB231 breast cancer cells.

Journal Article

Osteopontin (OPN) is a secreted phosphoprotein which mediates tumorigenesis, local growth, and metastasis in a variety of cancers. It is a potential therapeutic target for the regulation of cancer metastasis. RNA aptamer technology targeting OPN may represent a clinically viable therapy. In this study, we characterize the critical sequence of an RNA aptamer, termed OPN-R3, directed against human OPN. It has a K(d) of 18 nmol/l and binds specifically to human OPN as determined by RNA electrophoretic mobility assays. In MDA-MB231 human breast cancer cells examined under fluorescence microscopy, OPN-R3 ablates cell surface binding of OPN to its cell surface CD44 and alpha(v)beta(3) integrin receptors. Critical enzymatic components of the OPN signal transduction pathways, PI3K, JNK1/2, Src and Akt, and mediators of extracellular matrix degradation, matrix metalloproteinase 2 (MMP2) and uroplasminogen activator (uPA), are significantly decreased following exposure to OPN-R3. OPN-R3 inhibits MDA-MB231 in vitro adhesion, migration, and invasion characteristics by 60, 50, and 65%, respectively. In an in vivo xenograft model of breast cancer, OPN-R3 significantly decreases local progression and distant metastases. On the basis of this "proof-of-concept" study, we conclude that RNA aptamer targeting of OPN has biologically relevance for modifying tumor growth and metastasis.

Full Text

Duke Authors

Cited Authors

  • Mi, Z; Guo, H; Russell, MB; Liu, Y; Sullenger, BA; Kuo, PC

Published Date

  • January 2009

Published In

Volume / Issue

  • 17 / 1

Start / End Page

  • 153 - 161

PubMed ID

  • 18985031

Electronic International Standard Serial Number (EISSN)

  • 1525-0024

Digital Object Identifier (DOI)

  • 10.1038/mt.2008.235

Language

  • eng

Conference Location

  • United States