The recombinant anti-EGF receptor immunotoxin 425(scFv)-ETA' suppresses growth of a highly metastatic pancreatic carcinoma cell line.
Pancreatic carcinoma still has the highest mortality rate in comparison to any other malignancy. Major reasons are late detection of disease, highly aggressive tumor growth and the early formation of metastases. Thus, novel effective therapies are urgently needed to improve the outcome of the patients. Overexpression of the epidermal growth factor receptor (EGFR) and its ligands has been implicated in the oncogenesis of pancreatic carcinoma and associated with an unfavorable prognosis. Consequently, the EGFR represents a specific target antigen suitable for immunotherapy. We generated a recombinant immunotoxin by fusing the anti-EGFR single chain fragment 425(scFv) to a truncated mutant of Pseudomonas Exotoxin A (ETA'). Using the expression vector pBM1.1, functional 425(scFv)-ETA' was periplasmically expressed under osmotic stress conditions in the presence of compatible solutes. The 72 kDa His10-tagged fusion protein was purified by a combination of metal-ion affinity and molecular size chromatography. Binding activity and specificity of the immunotoxin to the EGFR-positive pancreatic carcinoma cell line L3.6pl was confirmed by flow cytometry and ELISA. Finally, 425(scFv)-ETA' showed significant toxicity toward this cell line reaching 50% inhibition of cell proliferation at a concentration (IC50) of 7.5 ng/ml. This is the first report documenting the specific cytotoxicity of a recombinant immunotoxin towards metastatic pancreatic carcinoma cells, suggesting that EGFR-specific antibody toxins may become valuable therapeutic reagents for the treatment of pancreatic carcinoma.
Bruell
Daniela
D
Department of Molecular Biotechnology, University Aachen, Aachen, Germany.
Stöcker
Michael
M
Huhn
Michael
M
Redding
Nicole
N
Küpper
Michael
M
Schumacher
Petra
P
Paetz
Antje
A
Bruns
Christiane J
CJ
Haisma
Hidde J
HJ
Fischer
Rainer
R
Finnern
Ricarda
R
Barth
Stefan
S
D002277:Carcinoma / Q000188:drug therapy*; D002455:Cell Division; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D004815:Epidermal Growth Factor / Q000737:chemistry*; D004926:Escherichia coli / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D007135:Immunoglobulin Variable Region / Q000737:chemistry*; D007167:Immunotherapy; D000922:Immunotoxins / Q000737:chemistry; D020128:Inhibitory Concentration 50; D008024:Ligands; D008957:Models, Genetic; D009154:Mutation; D009362:Neoplasm Metastasis; D010190:Pancreatic Neoplasms / Q000628:therapy*; D010957:Plasmids / Q000378:metabolism; D011379:Prognosis; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry*; D057127:Single-Chain Antibodies
C513566:425(scFv)-ETA'; D007135:Immunoglobulin Variable Region; D000922:Immunotoxins; D008024:Ligands; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D057127:Single-Chain Antibodies; C114035:scFv 425; D004815:Epidermal Growth Factor