Galectin-3 is strongly up-regulated in nonapoptosing mammary epithelial cells during rat mammary gland involution.
Galectin-3 is an endogenous mammalian lectin that binds to ABH carbohydrate antigens. Here we show that galectin-3 is strongly up-regulated during mammary gland involution and that it is expressed virtually exclusively on nonapoptotic cells. We demonstrate that dexamethasone, an inhibitor of the second phase of mammary gland involution, potently suppresses up-regulation of galectin-3 as judged immunohistochemically and on western blots, suggesting that systemic hormone levels regulate galectin-3 expression during involution. However, at the RNA level galectin-3 expression is rapidly up-regulated on the onset of involution but remains consistantly high during the first and second phase of involution regardless of dexamethasone treatment. These data suggest that the up-regulation of galectin-3 in the involuting mammary gland is not only controlled transcriptionally but also regulated posttranscriptionally under the control of systemic glucocorticoid hormones involved in coordinating the involution process.
Mengwasser
Jörg
J
Forschungszentrum Karlsruhe, Institute for Toxicology and Genetics, PO Box 3640, D-76021 Karlsruhe, Germany.
Liu
Fu-Tong
FT
Sleeman
Jonathan P
JP
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D000943:Antigens, Differentiation / Q000235:genetics / Q000378:metabolism*; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000378:metabolism; D017209:Apoptosis / Q000502:physiology*; D015152:Blotting, Northern; D015153:Blotting, Western; D003001:Cloning, Molecular; D017931:DNA Primers / Q000737:chemistry; D003907:Dexamethasone / Q000494:pharmacology; D004847:Epithelial Cells / Q000378:metabolism*; D005260:Female; D037502:Galectin 3; D007124:Immunoenzyme Techniques; D008321:Mammary Glands, Animal / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D014158:Transcription, Genetic; D015854:Up-Regulation / Q000187:drug effects
D000893:Anti-Inflammatory Agents; D000943:Antigens, Differentiation; D015295:Antigens, Tumor-Associated, Carbohydrate; D017931:DNA Primers; D037502:Galectin 3; C437397:M-N 1 antigen; D012333:RNA, Messenger; D003907:Dexamethasone