Coexpression of the sis and myc proto-oncogenes in developing human placenta suggests autocrine control of trophoblast growth.
First trimester human placentas actively express the sis proto-oncogene, the structural gene for the B chain of platelet-derived growth factor (PDGF). Using the in situ hybridization technique, the 4.2 kb c-sis transcript has been localized to the cytotrophoblastic component, especially the highly proliferative and invasive cytotrophoblastic shell, paralleling the distribution of c-myc transcripts in early placenta. Explants of first trimester placenta release significant levels of PDGF-like activity into the medium under apparent developmental control. Moreover, cultured trophoblasts display abundant high-affinity PDGF receptors and respond to exogenous authentic PDGF by an activation of the c-myc gene and DNA synthesis. The developing human placenta may therefore represent a case of autocrine growth regulation in a normal tissue, in which cells bearing receptors for a growth factor can also synthesize and respond to that factor.
Goustin
A S
AS
Betsholtz
C
C
Pfeifer-Ohlsson
S
S
Persson
H
H
Rydnert
J
J
Bywater
M
M
Holmgren
G
G
Heldin
C H
CH
Westermark
B
B
Ohlsson
R
R
D002460:Cell Line; D005260:Female; D005786:Gene Expression Regulation; D005796:Genes; D006801:Humans; D009693:Nucleic Acid Hybridization; D009857:Oncogenes; D010920:Placenta / Q000166:cytology / Q000378:metabolism*; D010982:Platelet-Derived Growth Factor / Q000096:biosynthesis / Q000235:genetics* / Q000494:pharmacology; D011247:Pregnancy; D000090063:Proto-Oncogene Mas; D011956:Receptors, Cell Surface / Q000032:analysis; D017479:Receptors, Platelet-Derived Growth Factor; D014327:Trophoblasts / Q000166:cytology / Q000378:metabolism*
C000715470:MAS1 protein, human; D010982:Platelet-Derived Growth Factor; D000090063:Proto-Oncogene Mas; D011956:Receptors, Cell Surface; D017479:Receptors, Platelet-Derived Growth Factor