Cytotoxic activities of a fusion protein comprised of TGF alpha and Pseudomonas exotoxin.
A cDNA encoding transforming growth factor type alpha (TGF alpha) was fused to the 5' end of a gene encoding a modified form of Pseudomonas exotoxin A (PE), which is devoid of the cell recognition domain (domain Ia). The chimeric molecule, termed TGF alpha-PE40, was expressed in Escherichia coli and isolated from the periplasm or inclusion bodies depending on the construction expressed. TGF alpha-PE40 was found to be extremely cytotoxic to cells displaying epidermal growth factor (EGF) receptors. Comparison with a similar molecule in which TGF alpha was placed at the carboxyl end of PE40 demonstrated the importance of the position of the cell recognition element; TGF alpha-PE40 was found to be about 30-fold more cytotoxic to cells bearing EGF receptors than PE40-TGF alpha. In addition, TGF alpha-PE40 was shown to be extremely cytotoxic to a variety of cancer cell lines including liver, ovarian, and colon cancer cell lines, indicating high levels of EGF receptor expression in these cells.
Siegall
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CB
Laboratory of Molecular Biology, National Cancer Institute, Bethesda, Maryland 20892.
Xu
Y H
YH
Chaudhary
V K
VK
Adhya
S
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Fitzgerald
D
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Pastan
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I
D036002:ADP Ribose Transferases; D001427:Bacterial Toxins; D001483:Base Sequence; D001667:Binding, Competitive; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy; D002470:Cell Survival; D003110:Colonic Neoplasms / Q000188:drug therapy; D004815:Epidermal Growth Factor / Q000378:metabolism; D066246:ErbB Receptors / Q000502:physiology; D004926:Escherichia coli / Q000235:genetics; D005098:Exotoxins / Q000235:genetics* / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D015870:Gene Expression; D008113:Liver Neoplasms / Q000188:drug therapy; D008969:Molecular Sequence Data; D010051:Ovarian Neoplasms / Q000188:drug therapy; D011993:Recombinant Fusion Proteins / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D016211:Transforming Growth Factor alpha; D015291:Transforming Growth Factors / Q000235:genetics* / Q000494:pharmacology* / Q000627:therapeutic use; D014407:Tumor Cells, Cultured; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A
D036002:ADP Ribose Transferases; D001427:Bacterial Toxins; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D005098:Exotoxins; D011993:Recombinant Fusion Proteins; D016211:Transforming Growth Factor alpha; D015291:Transforming Growth Factors; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A; C062005:transforming growth factor type alpha-Pseudomonas exotoxin A