Effect of mammary-derived growth inhibitor on proliferation of MAC-T bovine mammary epithelial cells.
An established bovine mammary epithelial cell line (MAC-T) was used as a model to examine the effect of mammary-derived growth inhibitor on mammary epithelial cell proliferation. Prior to each proliferation assay, cells were synchronized in G1/G0 by culturing for 24 h without serum. Flow cytometry revealed that 90% of cells were in G1/G0, 4% in G2/M, and 6% in the S-phase after serum deprivation. Approximately 2 x 10(3) cells per well were seeded onto 24-well plates. Cells were incubated for 5 to 6 d with various amounts of mammary-derived growth inhibitor (0 to 100 ng/ml). Mammary-derived growth inhibitor and medium were changed daily. Mammary-derived growth inhibitor decreased mammary epithelial cell proliferation at .1 ng/ml. Synchronization of cells in G1/G0 was necessary for inhibition of cell proliferation. Cells not arrested by serum deprivation were not responsive to mammary derived-growth inhibitor. Inhibition of cell proliferation was transient and observed up to 96 h in culture. Mammary-derived growth inhibitor appears to act in vitro by inhibiting the resumption of stationary cell proliferation following starvation.
Zavizion
B
B
Department of Animal Science, Cornell University, Ithaca, NY 14853.
Politis
I
I
Gorewit
R C
RC
Turner
J D
JD
Spitzer
E
E
Grosse
R
R
D000818:Animals; D002352:Carrier Proteins; D002417:Cattle; D002455:Cell Division / Q000187:drug effects*; D002460:Cell Line; D003470:Culture Media; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells; D050556:Fatty Acid-Binding Proteins; D005260:Female; D005434:Flow Cytometry; D016193:G1 Phase; D008321:Mammary Glands, Animal / Q000166:cytology*; D010455:Peptides / Q000008:administration & dosage / Q000494:pharmacology*; D016192:Resting Phase, Cell Cycle
D002352:Carrier Proteins; D003470:Culture Media; D050556:Fatty Acid-Binding Proteins; D010455:Peptides