Laminin inhibits lactotroph proliferation and is reduced in early prolactinoma development.
Laminin is a component of the extracellular matrix (ECM) that regulates cell proliferation and hormone secretion. Here we describe the effects of laminin on prolactin secretion in normal and tumor cells and analyze laminin expression pattern during prolactinoma development. Prolactin secretion and cell proliferation were inhibited by laminin in GH3 cells. In contrast, no effect was observed in normal pituitary cells. Laminin showed a dynamic expression pattern during prolactinoma development, which was: (a) strong in normal pituitaries from wild type or dopamine D2 receptor deficient mice, (b) lower in pituitary hyperplasia and (c) markedly reduced in prolactinomas from D2R -/- mice. A similar gradual decrease in laminin was found by comparing normal human pituitaries, human pituitary hyperplasia and human prolactinomas. These results show dynamic changes of laminin expression during prolactinoma formation which, due to laminin action on PRL production and cell proliferation, indicate a possible role for laminin in prolactinoma development.
Kuchenbauer
F
F
Max Planck Institute of Psychiatry, Neurosignaling Section, Kraepelinstr. 10, 80804, Munich, Germany.
Theodoropoulou
M
M
Hopfner
U
U
Stalla
J
J
Renner
U
U
Tonn
J C
JC
Low
M J
MJ
Arzt
E
E
Stalla
G K
GK
Páez-Pereda
M
M
D000704:Analysis of Variance; D000818:Animals; D002448:Cell Adhesion; D018929:Cell Culture Techniques / Q000379:methods; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor / Q000378:metabolism; D002478:Cells, Cultured; D013006:Growth Hormone / Q000378:metabolism; D006801:Humans; D006965:Hyperplasia / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D019012:Integrin beta1 / Q000378:metabolism; D007797:Laminin / Q000378:metabolism* / Q000494:pharmacology; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D010902:Pituitary Gland / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010911:Pituitary Neoplasms / Q000378:metabolism* / Q000473:pathology; D011388:Prolactin / Q000378:metabolism; D015175:Prolactinoma / Q000378:metabolism* / Q000473:pathology; D011485:Protein Binding; D011863:Radioimmunoassay; D051381:Rats; D017207:Rats, Sprague-Dawley; D017448:Receptors, Dopamine D2 / Q000235:genetics
D019012:Integrin beta1; D007797:Laminin; D017448:Receptors, Dopamine D2; D011388:Prolactin; D013006:Growth Hormone