TY - JOUR
T1 - Antimetastatic activity of insulin-like growth factor binding protein-3 in lung cancer is mediated by insulin-like growth factor-independent urokinase-type plasminogen activator inhibition
AU - Oh, Seung Hyun
AU - Lee, Ok Hee
AU - Schroeder, Claudia P.
AU - Oh, Yun W.
AU - Ke, Shi
AU - Cha, Hee Jae
AU - Park, Rang Woon
AU - Onn, Amir
AU - Herbst, Roy S.
AU - Li, Chun
AU - Lee, Ho Young
PY - 2006/11
Y1 - 2006/11
N2 - Insulin-like growth factor binding protein-3 (IGFBP-3), a major IGF-binding protein in human serum, regulates the growth of non-small cell lung cancer (NSCLC) cells through IGF-dependent and IGF-independent mechanisms. However, the role of IGFBP-3 in lung cancer metastasis is not well known. In the present study, we showed that noncytotoxic doses of adenoviral or recombinant IGFBP-3 significantly decreased the migration and invasion of H1299 and A549 NSCLC cells. Furthermore, treatment of human lung fibroblasts with recombinant IGFBP-3 suppressed their ability to stimulate the invasion of H1299 cells. Overexpression of IGFBP-3 markedly reduced lung metastasis of A549 cells in an experimental animal model system and prolonged the survival time of the animals. Urokinase-type plasminogen activator (uPA) inhibitor treatment or uPA small interfering RNA transfection of A549 and H1299 cells resulted in a significant decrease in invasion. Corresponding ELISA, Western blot, gelatin zymogram, and serniquantitative reverse transcription-PCR analyses revealed that IGFBP-3 reduced the expression of uPA mRNA through IGF-independent mechanisms. The specific role of uPA in anti-invasive activity of IGFBP-3 was further confirmed in NSCLC cells, in which uPA expression/activity was suppressed by the transfection with synthetic small interfering RNA or by the treatment with uPA inhibitor or induced by the infection with an adenoviral vector. IGFBP-3 also decreased the expression/activity of matrix metalloproteinase-2 through IGF-dependent but uPA-independent pathways. Taken together, our data suggest that IGFPB-3 effectively block uPA- and matrix metalloproteinase-2 -stimulated invasion pathways, ultimately reducing lung cancer cell metastasis. Our findings indicate that IGFBP-3 may be a promising anti-invasive and antimetastatic therapeutic agent in lung cancer.
AB - Insulin-like growth factor binding protein-3 (IGFBP-3), a major IGF-binding protein in human serum, regulates the growth of non-small cell lung cancer (NSCLC) cells through IGF-dependent and IGF-independent mechanisms. However, the role of IGFBP-3 in lung cancer metastasis is not well known. In the present study, we showed that noncytotoxic doses of adenoviral or recombinant IGFBP-3 significantly decreased the migration and invasion of H1299 and A549 NSCLC cells. Furthermore, treatment of human lung fibroblasts with recombinant IGFBP-3 suppressed their ability to stimulate the invasion of H1299 cells. Overexpression of IGFBP-3 markedly reduced lung metastasis of A549 cells in an experimental animal model system and prolonged the survival time of the animals. Urokinase-type plasminogen activator (uPA) inhibitor treatment or uPA small interfering RNA transfection of A549 and H1299 cells resulted in a significant decrease in invasion. Corresponding ELISA, Western blot, gelatin zymogram, and serniquantitative reverse transcription-PCR analyses revealed that IGFBP-3 reduced the expression of uPA mRNA through IGF-independent mechanisms. The specific role of uPA in anti-invasive activity of IGFBP-3 was further confirmed in NSCLC cells, in which uPA expression/activity was suppressed by the transfection with synthetic small interfering RNA or by the treatment with uPA inhibitor or induced by the infection with an adenoviral vector. IGFBP-3 also decreased the expression/activity of matrix metalloproteinase-2 through IGF-dependent but uPA-independent pathways. Taken together, our data suggest that IGFPB-3 effectively block uPA- and matrix metalloproteinase-2 -stimulated invasion pathways, ultimately reducing lung cancer cell metastasis. Our findings indicate that IGFBP-3 may be a promising anti-invasive and antimetastatic therapeutic agent in lung cancer.
UR - http://www.scopus.com/inward/record.url?scp=33845230171&partnerID=8YFLogxK
U2 - 10.1158/1535-7163.MCT-06-0142
DO - 10.1158/1535-7163.MCT-06-0142
M3 - Article
C2 - 17121915
AN - SCOPUS:33845230171
SN - 1535-7163
VL - 5
SP - 2685
EP - 2695
JO - Molecular Cancer Therapeutics
JF - Molecular Cancer Therapeutics
IS - 11
ER -
