Urinary transforming growth factors in neoplasia: separation of /sup 125/I-labeled transforming growth factor-alpha from epidermal growth factor in human urine
Purified human epidermal growth factor (hEGF) from urine promotes anchorage-independent cell growth in soft agar medium. This growth is enhanced by transforming growth factor-beta (TGF-beta), and is specifically inhibited by hEGF antiserum. Transforming growth factors of the alpha type (TGF-alpha), potentially present in normal human urine or urine from tumor-bearing patients, also promote anchorage-independent cell growth and compete with EGF for membrane receptor binding. Consequently, TGF-alpha cannot be distinguished from urinary hEGF by these two functional assays. Therefore, a technique for separation of TGF-alpha and related peptides from urinary EGF based on biochemical characteristics would be useful. Radioiodination of characterized growth factors (mouse EGF (mEGF), hEGF, and rat TGF-alpha (rTGF-alpha)), which were then separately added to human urine, was used to evaluate a resolution scheme that separates TGF-alpha from the high level of background hEGF present in human urine. Methyl bonded microparticulate silica efficiently adsorbed the /sup 125/I-labeled mEGF, /sup 125/I-labeled hEGF, and /sup 125/I-labeled rTGF-alpha that were added to 24-h human urine samples. Fractional elution with acetonitrile (MeCN) of the adsorbed silica released approximately 70 to 80% of the /sup 125/I-labeled mEGF and /sup 125/I-labeled hEGF between 25 and 30% MeCN, and over 80% of the /sup 125/I-labeled rTGF-alpha between 15 and 25% MeCN, with retention after dialysis of less than 0.2 and 1.7% of the original urinary protein, respectively. A single-step enrichment of about 400-fold for mEGF and hEGF, and 50-fold for rTGF-alpha were achieved rapidly. /sup 125/I-labeled mEGF and /sup 125/I-labeled hEGF eluted later than would be predicted on the basis of their reported molecular weight of approximately 6000, whereas /sup 125/I-labeled rTGF-alpha eluted from Bio-Gel P-10 at an approximate molecular weight of 8000 to 9000.
- Research Organization:
- National Cancer Institute, Frederick, MD
- OSTI ID:
- 6851479
- Journal Information:
- Cancer Res.; (United States), Vol. 11
- Country of Publication:
- United States
- Language:
- English
Similar Records
Radioreceptor assay for epidermal growth factor. [/sup 125/I tracer technique, mice]
cap alpha. -transforming growth factor secreted by untransformed bovine anterior pituitary cells in culture. I. Purification from conditioned medium
Related Subjects
HORMONES
SEPARATION PROCESSES
ADSORPTION
CHROMATOGRAPHY
IODINATION
IODINE 125
LABELLED COMPOUNDS
MOLECULAR WEIGHT
NEOPLASMS
PEPTIDES
RADIOCHEMISTRY
SILICA
SOLUBILITY
TRACER TECHNIQUES
URINE
BETA DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BIOLOGICAL WASTES
BODY FLUIDS
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISTRY
DAYS LIVING RADIOISOTOPES
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
HALOGENATION
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MATERIALS
MINERALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PROTEINS
RADIOISOTOPES
SILICON COMPOUNDS
SILICON OXIDES
SORPTION
WASTES
550201* - Biochemistry- Tracer Techniques