Sustained co-cultivation with human placenta-derived MSCs enhances ALK5/Smad3 signaling in human breast epithelial cells, leading to EMT and differentiation.
The interaction between mammary epithelial cells and their surrounding microenvironment are important in the development of the mammary gland. Thus, mesenchymal stem cells (MSCs), which retain pluripotency for various mesenchymal lineages, may provide a permissive environment for the morphologic alteration and differentiation of mammary epithelial cells. To this end, we investigated whether the interactions between mammary epithelial cells and human placenta-derived MSCs (hPMSC) affect the morphology, proliferation, and differentiation of epithelial cells in a co-culture system. We show that after co-culture with hPMSCs, human mammary epithelial cell lines (MCF-10F and HEMC) underwent significant morphologic alterations and a dramatic increase in ductal-alveolar branching, which was accompanied by a decrease or loss of the epithelial marker E-cadherin and a gain of the mesenchymal markers, alpha-SMA and vimentin. MCF-10F and HEMC proliferation was also inhibited in the presence of hPMSCs, and this retardation in growth was due to cell cycle arrest. Furthermore, in MCF-10F and HMEC cells, hPMSCs induced the production of lipid droplets, milk fat globule protein, and milk protein lactoferrin, which are markers of functional mammary differentiation. We also noticed an elevation in ALK5 and phosphorylated Smad3 protein levels upon hPMSC co-culture. Strikingly, the changes in morphology, proliferation, and differentiation were reversed by treatment with ALK5 or Smad3 knockdown in MCF-10F/hPMSC co-cultures. Collectively, our findings suggest that co-cultivation with hPMSCs leads to epithelial to mesenchymal transition (EMT) and differentiation of human breast epithelial cells through the ALK5/Smad3 signaling pathway.
Brain Korea 21 Program for Biomedical Science, Korea University College of Medicine, Korea University, Seoul 136-705, South Korea.
Young A
YA
Yoo
Myoung Hee
MH
Kang
Byung Soo
BS
Kim
Jun Suk
JS
Kim
Jae Hong
JH
Seo
D001940:Breast / Q000166:cytology; D002454:Cell Differentiation; D018920:Coculture Techniques; D004848:Epithelium / Q000378:metabolism; D005260:Female; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism*; D008648:Mesoderm / Q000166:cytology / Q000378:metabolism; D010920:Placenta / Q000166:cytology; D011247:Pregnancy; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism*; D015398:Signal Transduction; D051900:Smad3 Protein / Q000378:metabolism*
D018125:Receptors, Transforming Growth Factor beta; C497790:SMAD3 protein, human; D051900:Smad3 Protein; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I; C000625841:TGFBR1 protein, human