Human mammary tumor cell proliferation: primary role of platelet-derived growth factor and possible synergism with human alpha-fetoprotein.
Human mammary medullary carcinoma cells (passages 16 to 21) were cultured for 2 days to allow for attachment, followed by 6 days of culture in either fetal calf serum, human cord blood, human amniotic fluid, or growth factors in the presence or absence of purified human alpha-fetoprotein (AFP). When growth factors were tested alone, only platelet-derived growth factor produced a significant increase in cell proliferation. Although up to 40% amniotic fluid had no effect on cell proliferation, human cord blood was two-fold more potent than fetal calf serum at similar concentrations. The addition of 10 ng/ml of platelet-derived growth factor increased the proliferative activity of human cord blood 1.5- to 2.5-fold. Ablation of endogenous AFP by affinity chromatography reduced the proliferative activity of cord blood by 75%. Similarly, the mitogenic activity of cord blood plus platelet-derived growth factor was reduced by 56% when AFP was removed. Purified AFP dose-dependently enhanced the proliferative activity of platelet-derived growth factor. This synergistic effect was specific for platelet-derived growth factor. We conclude that platelet-derived growth factor is a major growth factor controlling the proliferation of these tumor cells and that AFP may enhance growth factor proliferative activity and human mammary tumor growth.
Leal
J A
JA
Department of Obstetrics and Gynecology, University of Kansas School of Medicine-Wichita 67214-4716.
Gangrade
B K
BK
Kiser
J L
JL
May
J V
JV
Keel
B A
BA
D000653:Amniotic Fluid / Q000502:physiology; D001790:Blood Physiological Phenomena; D001943:Breast Neoplasms / Q000473:pathology*; D005312:Fetal Blood / Q000737:chemistry / Q000502:physiology; D006133:Growth Substances / Q000502:physiology; D006801:Humans; D010982:Platelet-Derived Growth Factor / Q000502:physiology*; D014407:Tumor Cells, Cultured; D000509:alpha-Fetoproteins / Q000502:physiology*
D006133:Growth Substances; D010982:Platelet-Derived Growth Factor; D000509:alpha-Fetoproteins