TY - JOUR
T1 - A human monoclonal antibody against insulin-like growth factor-II blocks the growth of human hepatocellular carcinoma cell lines in vitro and in vivo
AU - Dransfield, Daniel T.
AU - Cohen, Edward H.
AU - Chang, Qing
AU - Sparrow, Lindsay G.
AU - Bentley, John D.
AU - Dolezal, Olan
AU - Xiao, Xiaowen
AU - Peat, Thomas S.
AU - Newman, Janet
AU - Pilling, Patricia A.
AU - Phan, Tram
AU - Priebe, Ilka
AU - Brierley, Gemma V.
AU - Kastrapeli, Niksa
AU - Kopacz, Kris
AU - Martik, Diana
AU - Wassaf, Dina
AU - Rank, Douglas
AU - Conley, Greg
AU - Huang, Yan
AU - Adams, Timothy E.
AU - Cosgrove, Leah
PY - 2010/6
Y1 - 2010/6
N2 - Elevated expression of insulin-like growth factor-II (IGF-II) is frequently observed in a variety of human malignancies, including breast, colon, and liver cancer. As IGF-II can deliver a mitogenic signal through both IGF-IR and an alternately spliced form of the insulin receptor (IR-A), neutralizing the biological activity of this growth factor directly is a potential alternative option to IGF-IR-directed agents. Using a Fab-displaying phage library and a biotinylated precursor form of IGF-II (1-104 amino acids) as a target, we isolated Fabs specific for the E-domain COOH-terminal extension form of IGF-II and for mature IGF-II. One of these Fabs that bound to both forms of IGF-II was reformatted into a full-length IgG, expressed, purified, and subjected to further analysis. This antibody (DX-2647) displayed a very high affinity for IGF-II/IGF-IIE (KD value of 49 and 10 pmol/L, respectively) compared with IGF-I (∼10 nmol/L) and blocked binding of IGF-II to IGF-IR, IR-A, a panel of insulin-like growth factor-binding proteins, and the mannose-6-phosphate receptor. A crystal complex of the parental Fab of DX-2647 bound to IGF-II was resolved to 2.2 Å. DX-2647 inhibited IGF-II and, to a lesser extent, IGF-I-induced receptor tyrosine phosphorylation, cellular proliferation, and both anchorage-dependent and anchorage-independent colony formation in various cell lines. In addition, DX-2647 slowed tumor progression in the Hep3B xenograft model, causing decreased tumoral CD31 staining as well as reduced IGF-IIE and IGF-IR phosphorylation levels. Therefore, DX-2647 offers an alternative approach to targeting IGF-IR, blocking IGF-II signaling through both IGF-IR and IR-A.
AB - Elevated expression of insulin-like growth factor-II (IGF-II) is frequently observed in a variety of human malignancies, including breast, colon, and liver cancer. As IGF-II can deliver a mitogenic signal through both IGF-IR and an alternately spliced form of the insulin receptor (IR-A), neutralizing the biological activity of this growth factor directly is a potential alternative option to IGF-IR-directed agents. Using a Fab-displaying phage library and a biotinylated precursor form of IGF-II (1-104 amino acids) as a target, we isolated Fabs specific for the E-domain COOH-terminal extension form of IGF-II and for mature IGF-II. One of these Fabs that bound to both forms of IGF-II was reformatted into a full-length IgG, expressed, purified, and subjected to further analysis. This antibody (DX-2647) displayed a very high affinity for IGF-II/IGF-IIE (KD value of 49 and 10 pmol/L, respectively) compared with IGF-I (∼10 nmol/L) and blocked binding of IGF-II to IGF-IR, IR-A, a panel of insulin-like growth factor-binding proteins, and the mannose-6-phosphate receptor. A crystal complex of the parental Fab of DX-2647 bound to IGF-II was resolved to 2.2 Å. DX-2647 inhibited IGF-II and, to a lesser extent, IGF-I-induced receptor tyrosine phosphorylation, cellular proliferation, and both anchorage-dependent and anchorage-independent colony formation in various cell lines. In addition, DX-2647 slowed tumor progression in the Hep3B xenograft model, causing decreased tumoral CD31 staining as well as reduced IGF-IIE and IGF-IR phosphorylation levels. Therefore, DX-2647 offers an alternative approach to targeting IGF-IR, blocking IGF-II signaling through both IGF-IR and IR-A.
UR - http://www.scopus.com/inward/record.url?scp=77953440123&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77953440123&partnerID=8YFLogxK
U2 - 10.1158/1535-7163.MCT-09-1134
DO - 10.1158/1535-7163.MCT-09-1134
M3 - Article
C2 - 20515953
AN - SCOPUS:77953440123
SN - 1535-7163
VL - 9
SP - 1809
EP - 1819
JO - Molecular cancer therapeutics
JF - Molecular cancer therapeutics
IS - 6
ER -