Purification of a novel protein (ps20) from urogenital sinus mesenchymal cells with growth inhibitory properties in vitro.
Our previous studies have characterized mesenchyme-derived proteins to identify biologically active proteins and novel markers for stromal cell paracrine action relative to stromal-epithelial interactions. Previous reports have characterized properties of a growth inhibitory activity (to bladder and prostatic epithelial cells), secreted by U4F fetal rat urogenital sinus mesenchymal cells, not cross-reactive with antibodies to known cytokines, and provisionally termed UGIF. The present study reports the characterization, purification, and biological properties of a 20-21-kDa protein responsible for UGIF activity. The 20-21-kDa protein (termed ps20) was purified to near homogeneity, the amino-terminal sequence was determined, and biological properties were characterized in vitro. Amino-terminal sequence analysis indicated no direct matches or regions of homology with known proteins. Purified ps20 induced a linear and saturable inhibition of [3H]thymidine incorporation in PC-3 prostatic carcinoma cells (half-maximal activity at 2.6 nM), inhibited cell proliferation (increased population doubling time from 19.8 to 25.8 h), and induced a 210% stimulation in the synthesis of secreted proteins. These data suggest that ps20 may be a candidate paracrine effector protein and may play a role in stromal-epithelial cell interaction in the prostate gland.
Rowley
D R
DR
Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
Dang
T D
TD
Larsen
M
M
Gerdes
M J
MJ
McBride
L
L
Lu
B
B
D000818:Animals; D002455:Cell Division; D002460:Cell Line; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D003238:Connective Tissue / Q000378:metabolism*; D003239:Connective Tissue Cells; D004591:Electrophoresis, Polyacrylamide Gel; D004847:Epithelial Cells; D005333:Fetus; D006131:Growth Inhibitors / Q000096:biosynthesis* / Q000302:isolation & purification / Q000494:pharmacology; D036341:Intercellular Signaling Peptides and Proteins; D008297:Male; D008970:Molecular Weight; D011467:Prostate / Q000166:cytology; D014176:Protein Biosynthesis; D011506:Proteins / Q000302:isolation & purification / Q000494:pharmacology; D051381:Rats; D001743:Urinary Bladder / Q000166:cytology; D014566:Urogenital System / Q000166:cytology / Q000378:metabolism*
D006131:Growth Inhibitors; D036341:Intercellular Signaling Peptides and Proteins; D011506:Proteins; C095570:Wfdc1 protein, rat