Detection and location of amphiregulin and Cripto-1 expression in the developing postnatal mouse mammary gland.
Amphiregulin (Ar) and Cripto-1 (Cr-1) are growth promoting peptides that share amino acid sequence homology with epidermal growth factor (EGF). The present study examined Ar and Cr-1 mRNA and protein expression during various stages of C57BL/6 mouse mammary morphogenesis. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect transcripts for Ar and Cr-1 at all stages of mammary development. Immunocytochemical (ICC) localization demonstrated that in virgin 4-week to mature 12-week-old mouse fourth inguinal mammary gland, Ar and Cr-1 are expressed in the stromal cells, luminal epithelial cells, and myoepithelial cells of the branching ducts. Ar, and to lesser extent Cr-1, were also found in the epithelial cap cells and in the luminal epithelial cells of the advancing terminal end bud (TEB) from virgin 4-week and 6-week-old mice. Western blot analysis demonstrated that both Ar (28 and 26 kDa) and Cr-1 (90, 67, 56, and 21 kDa) proteins are expressed in virgin, 13.5 day midpregnant and in the 14 day lactating mammary gland. In addition, Ar and Cr-1 are associated with developing alveolar structures as determined by ICC. These results imply that together with EGF and transforming growth factor alpha (TGF alpha), Ar and Cr-1 may play salient roles as modifiers in the morphogenesis and differentiation of the mammary gland.
Kenney
N J
NJ
La Jolla Cancer Research Foundation, California 92037, USA.
Huang
R P
RP
Johnson
G R
GR
Wu
J X
JX
Okamura
D
D
Matheny
W
W
Kordon
E
E
Gullick
W J
WJ
Plowman
G
G
Smith
G H
GH
D066258:Amphiregulin; D000818:Animals; D002478:Cells, Cultured; D066255:EGF Family of Proteins; D004815:Epidermal Growth Factor; D005260:Female; D006023:Glycoproteins / Q000096:biosynthesis*; D006133:Growth Substances / Q000096:biosynthesis*; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins; D008321:Mammary Glands, Animal / Q000196:embryology / Q000378:metabolism*; D008562:Membrane Glycoproteins; D051379:Mice; D008810:Mice, Inbred C57BL; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D012333:RNA, Messenger / Q000032:analysis
D066258:Amphiregulin; C587849:Areg protein, mouse; D066255:EGF Family of Proteins; D006023:Glycoproteins; D006133:Growth Substances; D036341:Intercellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; C489450:Tdgf1 protein, mouse; D004815:Epidermal Growth Factor