Human A673 cells secrete high molecular weight EGF-receptor binding growth factors that appear to be immunologically unrelated to EGF or TGF-α
✍ Scribed by Kurt Stromberg; W. Robert Hudgins; Charlotte M. Fryling; Parul Hazarika; John R. Dedman; Robert L. Pardue; William R. Hargreaves; David N. Orth
- Book ID
- 102879765
- Publisher
- John Wiley and Sons
- Year
- 1986
- Tongue
- English
- Weight
- 775 KB
- Volume
- 32
- Category
- Article
- ISSN
- 0730-2312
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✦ Synopsis
Extracts of serum-free conditioned medium from human rhabdomyosarcoma A673 cells contain high molecular weight (HMW) transforming growth factors (TGFs) that can be partially purified by Bio-Gel P-100 and carboxymethyl (CM)-cellulose chromatography (Todaro et al: Proc Natl Acad Sci USA 775258, 1980). Reversephase high performance liquid chromatography (HPLC) revealed a principal peak of epidermal growth factor (EGF) radioreceptor assay (RRA) activity and anchorage-independent growth (AIG) activity that coeluted with 25-26 % acetonitrile. If a trailing shoulder of EGF RRA activity from the CM-C chromatography was included in the material for HPLC analysis, additional active fractions were observed at 21-22 % acetonitrile. Importantly, both active regions from HPLC failed to compete in radioimmunoassays under reduced and denatured conditions for human EGF (hEGF), human TGF-a (hTGF-a), or rat TGF-a (rTGF-a) and failed to give positive signals in Western blots under conditions in which TGF-(r was readily detected when using an antisera raised against the 17 C-terminal amino acids of rTGF-a. Nonreducing sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) revealed EGF RRA and AIG activities in gel slices corresponding to M, 15,000 and 22,000 in the 2 5 2 6 % acetonitrile eluate and M,