TY - JOUR
T1 - A deimmunized bispecific ligand-directed toxin that shows an impressive anti-pancreatic cancer effect in a systemic nude mouse orthotopic model
AU - Oh, Seunguk
AU - Todhunter, Deborah A.
AU - Panoskaltsis-Mortari, Angela
AU - Buchsbaum, Donald J.
AU - Toma, Shoko
AU - Vallera, Daniel A.
PY - 2012/7
Y1 - 2012/7
N2 - Objective: The objective was to test a bispecific ligand-directed toxin (BLT), with reduced immunogenicity for enhanced efficacy in targeting orthotopic pancreatic cancer in vivo. Method: A new BLT was created in which both human epidermal growth factor (EGF) and interleukin 4 cytokines were cloned onto the same single chain molecule with deimmunized pseudomonas exotoxin (dEGF4KDEL). Key amino acids dictating B-cell generation of neutralizing antitoxin antibodies were mutated. Bioassays were used to determine whether mutation reduced potency, and enzyme-linked immunosorbent assay studies were performed to determine whether antitoxin antibodies were reduced. A genetically altered luciferase MIA PaCa-2 xenograft model was used to image in real time and determine effects on systemic malignant human cancer. Bispecific ligand-directed toxins targeting B cells were used as specificity controls. Results: Deimmunized EGF4KDEL was significantly effective after systemic injection against established orthotopic MIA PaCa-2 pancreatic cancer and selectively prevented metastasis. Mutagenesis significantly reduced antitoxin levels in vivo with no apparent activity loss in vitro. The drug was effective against 3 human pancreatic cancer lines in vitro, MIA PaCa-2, SW1990, and S2VP10. Conclusions: Despite the metastatic nature of the MIA PaCa-2 orthotopic tumor xenografted in nude mice, high percentages of tumors responded to extended dEGFKDEL treatment resulting in significant anticancer effects and disease-free survivors.
AB - Objective: The objective was to test a bispecific ligand-directed toxin (BLT), with reduced immunogenicity for enhanced efficacy in targeting orthotopic pancreatic cancer in vivo. Method: A new BLT was created in which both human epidermal growth factor (EGF) and interleukin 4 cytokines were cloned onto the same single chain molecule with deimmunized pseudomonas exotoxin (dEGF4KDEL). Key amino acids dictating B-cell generation of neutralizing antitoxin antibodies were mutated. Bioassays were used to determine whether mutation reduced potency, and enzyme-linked immunosorbent assay studies were performed to determine whether antitoxin antibodies were reduced. A genetically altered luciferase MIA PaCa-2 xenograft model was used to image in real time and determine effects on systemic malignant human cancer. Bispecific ligand-directed toxins targeting B cells were used as specificity controls. Results: Deimmunized EGF4KDEL was significantly effective after systemic injection against established orthotopic MIA PaCa-2 pancreatic cancer and selectively prevented metastasis. Mutagenesis significantly reduced antitoxin levels in vivo with no apparent activity loss in vitro. The drug was effective against 3 human pancreatic cancer lines in vitro, MIA PaCa-2, SW1990, and S2VP10. Conclusions: Despite the metastatic nature of the MIA PaCa-2 orthotopic tumor xenografted in nude mice, high percentages of tumors responded to extended dEGFKDEL treatment resulting in significant anticancer effects and disease-free survivors.
KW - EGF
KW - Immunoconjugate therapy
KW - Immunotoxin
KW - Pancreatic cancer
KW - Pseudomonas exotoxin
KW - Xenograft model
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U2 - 10.1097/MPA.0b013e31823b5f2e
DO - 10.1097/MPA.0b013e31823b5f2e
M3 - Article
C2 - 22258068
AN - SCOPUS:84863724580
SN - 0885-3177
VL - 41
SP - 789
EP - 796
JO - Pancreas
JF - Pancreas
IS - 5
ER -