Identification of a pepsin-sensitive type III-like collagen in breast cancer MCF-7 cells.
Electrophoretic analysis of [3H]proline-labeled culture medium proteins of MCF-7 cells revealed the presence of disulfide-bonded, bacterial collagenase-sensitive component which comigrated with pro(alpha)1 chains of type III and type I collagens. However, it was pepsin- and trypsin-sensitive. Within 1 min of pepsin-digestion, a component with a size of alpha1 chain of type I or III collagen was produced which degraded after 5 min of digestion. Similarly, the pepsin-sensitive band was completely degraded by trypsin at 30 degrees C within 5 min. We examined CNBr peptides of the collagenous band and demonstrated that it was alpha1 chain of type III collagen. When MCF-7 cells were cultured in the presence of 2 nM estradiol, a marked increase in the level of collagen secreted into medium was found. The identified proteinase-sensitive type III-like collagen as major protein of extracellular matrix, would be expected to be more susceptible to degradation which might contribute to tumor progression.
Galicka
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Department of General and Organic Chemistry, Medical Academy of Bialystok, Poland. angajko@amb.ac.bialystok.pl
Wolczynski
S
S
Anchim
T
T
Gindzienski
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D001943:Breast Neoplasms / Q000378:metabolism*; D024061:Collagen Type III / Q000302:isolation & purification* / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D004958:Estradiol / Q000494:pharmacology; D006801:Humans; D008970:Molecular Weight; D010434:Pepsin A / Q000378:metabolism*; D010446:Peptide Fragments / Q000302:isolation & purification; D014407:Tumor Cells, Cultured
D024061:Collagen Type III; D010446:Peptide Fragments; D004958:Estradiol; D010434:Pepsin A