TY - JOUR
T1 - Antitumor activity of a humanized, bivalent immunotoxin targeting Fn14-positive solid tumors
AU - Zhou, Hong
AU - Hittelman, Walter N.
AU - Yagita, Hideo
AU - Cheung, Lawrence H.
AU - Martin, Stuart S.
AU - Winkles, Jeffrey A.
AU - Rosenblum, Michael G.
PY - 2013/7/15
Y1 - 2013/7/15
N2 - The TNF-like weak inducer of apoptosis (TWEAK; TNFSF12) receptor Fn14 (TNFRSF12A) is expressed at low levels in normal tissues but frequently highly expressed in a wide range of tumor types such as lung, melanoma, and breast, and therefore it is a potentially unique therapeutic target for these diverse tumor types. We have generated a recombinant protein containing a humanized, dimeric single-chain anti-fibroblast growth factorinducible 14-kDa protein (Fn14) antibody fused to recombinant gelonin toxin as a potential therapeutic agent (designated hSGZ). The hSGZ immunotoxin is a highly potent and selective agent that kills Fn14-positive (Fn14+) tumor cells in vitro. Treatment of cells expressing the MDR protein MDR1 (ABCB1B) showed no cross-resistance to hSGZ. Induced overexpression of Fn14 levels in MCF7 cells through HER2 (ERBB2) signaling translated to an improved therapeutic index of hSGZ treatment. In combination with trastuzumab, hSGZ showed an additive or synergistic cytotoxic effect on HER2+/Fn14+ breast cancer cell lines. Also, hSGZ treatment inhibited Erb3/Akt signaling in HER2-overexpressing breast cancer cells. Pharmacokinetic studies in mice revealed that hSGZ exhibited a biexponential clearance from plasma with a rapid initial clearance (t 1/2α = 1.26 hours) followed by a seven-fold longer plasma half-life (t1/2β; = 7.29 hours). At 24, 48, and 72 hours after injection, uptake of the hSGZ into tumors was 5.1, 4.8, and 4.7%ID/g, with a tumor-to-muscle ratio of 5.6, 6.2, and 9.0, respectively. Therapeutic efficacy studies showed significant tumor inhibition effects using an MDA-MB-231/Luc breast cancer xenograft model. Our findings show that hSGZ is an effective anticancer agent and a potential candidate for clinical studies.
AB - The TNF-like weak inducer of apoptosis (TWEAK; TNFSF12) receptor Fn14 (TNFRSF12A) is expressed at low levels in normal tissues but frequently highly expressed in a wide range of tumor types such as lung, melanoma, and breast, and therefore it is a potentially unique therapeutic target for these diverse tumor types. We have generated a recombinant protein containing a humanized, dimeric single-chain anti-fibroblast growth factorinducible 14-kDa protein (Fn14) antibody fused to recombinant gelonin toxin as a potential therapeutic agent (designated hSGZ). The hSGZ immunotoxin is a highly potent and selective agent that kills Fn14-positive (Fn14+) tumor cells in vitro. Treatment of cells expressing the MDR protein MDR1 (ABCB1B) showed no cross-resistance to hSGZ. Induced overexpression of Fn14 levels in MCF7 cells through HER2 (ERBB2) signaling translated to an improved therapeutic index of hSGZ treatment. In combination with trastuzumab, hSGZ showed an additive or synergistic cytotoxic effect on HER2+/Fn14+ breast cancer cell lines. Also, hSGZ treatment inhibited Erb3/Akt signaling in HER2-overexpressing breast cancer cells. Pharmacokinetic studies in mice revealed that hSGZ exhibited a biexponential clearance from plasma with a rapid initial clearance (t 1/2α = 1.26 hours) followed by a seven-fold longer plasma half-life (t1/2β; = 7.29 hours). At 24, 48, and 72 hours after injection, uptake of the hSGZ into tumors was 5.1, 4.8, and 4.7%ID/g, with a tumor-to-muscle ratio of 5.6, 6.2, and 9.0, respectively. Therapeutic efficacy studies showed significant tumor inhibition effects using an MDA-MB-231/Luc breast cancer xenograft model. Our findings show that hSGZ is an effective anticancer agent and a potential candidate for clinical studies.
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UR - http://www.scopus.com/inward/citedby.url?scp=84880905289&partnerID=8YFLogxK
U2 - 10.1158/0008-5472.CAN-13-0187
DO - 10.1158/0008-5472.CAN-13-0187
M3 - Article
C2 - 23722548
AN - SCOPUS:84880905289
SN - 0008-5472
VL - 73
SP - 4439
EP - 4450
JO - Cancer Research
JF - Cancer Research
IS - 14
ER -