Cyclic AMP regulates formation of mammary epithelial acini in vitro.
Epithelial cells form tubular and acinar structures notable for a hollow lumen. In three-dimensional culture utilizing MCF10A mammary epithelial cells, acini form due to integrin-dependent polarization and survival of cells contacting extracellular matrix (ECM), and the apoptosis of inner cells of acini lacking contact with the ECM. In this paper, we report that cyclic AMP (cAMP)-dependent protein kinase A (PKA) promotes acinus formation via two mechanisms. First, cAMP accelerates redistribution of α6-integrin to the periphery of the acinus and thus facilitates the polarization of outer acinar cells. Blocking of α6-integrin function by inhibitory antibody prevents cAMP-dependent polarization. Second, cAMP promotes the death of inner cells occupying the lumen. In the absence of cAMP, apoptosis is delayed, resulting in perturbed luminal clearance. cAMP-dependent apoptosis is accompanied by a posttranscriptional PKA-dependent increase in the proapoptotic protein Bcl-2 interacting mediator of cell death. These data demonstrate that cAMP regulates lumen formation in mammary epithelial cells in vitro, both through acceleration of polarization of outer cells and apoptosis of inner cells of the acinus.
Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143-2140, USA.
Pavel I
PI
Nedvetsky
Sang-Ho
SH
Kwon
Jayanta
J
Debnath
Keith E
KE
Mostov
D061354:Acinar Cells / Q000166:cytology / Q000378:metabolism; D017209:Apoptosis / Q000235:genetics; D018929:Cell Culture Techniques; D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism; D005260:Female; D006801:Humans; D039503:Integrin alpha6 / Q000378:metabolism; D042361:Mammary Glands, Human / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D009024:Morphogenesis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism
D039503:Integrin alpha6; D019253:Proto-Oncogene Proteins c-bcl-2; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases