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. 1985 May 1;100(5):1415–1422. doi: 10.1083/jcb.100.5.1415

Cell-cell interactions promote mammary epithelial cell differentiation

PMCID: PMC2113870  PMID: 3886667

Abstract

Mammary epithelium differentiates in a stromal milieu of adipocytes and fibroblasts. To investigate cell-cell interactions that may influence mammary epithelial cell differentiation, we developed a co-culture system of murine mammary epithelium and adipocytes and other fibroblasts. Insofar as caseins are specific molecular markers of mammary epithelial differentiation, rat anti-mouse casein monoclonal antibodies were raised against the three major mouse casein components to study this interaction. Mammary epithelium from mid-pregnant mice was plated on confluent irradiated monolayers of 3T3-L1 cells, a subclone of the Swiss 3T3 cell line that differentiates into adipocytes in monolayer culture and other cell monolayers (3T3-C2 cells, Swiss 3T3 cells, and human foreskin fibroblasts). Casein was synthesized by mammary epithelium only in the presence of co-cultured cells and the lactogenic hormone combination of insulin, hydrocortisone, and prolactin. Synthesis and accumulation of alpha-, beta-, and gamma-mouse casein within the epithelium was shown by immunohistochemical staining of cultured cells with anti-casein monoclonal antibodies, and the specificity of the immunohistochemical reaction was demonstrated using immunoblots. A competitive immunoassay was used to measure the amount of casein secreted into the culture medium. In a 24-h period, mammary epithelium co-cultured with 3T3-L1 cells secreted 12-20 micrograms beta- casein per culture dish. There was evidence of specificity in the cell- cell interaction that mediates hormone-dependent casein synthesis. Swiss 3T3 cells, newborn foreskin fibroblasts, substrate-attached material ("extracellular matrix"), and tissue culture plastic did not support casein synthesis, whereas monolayers of 3T3-L1 and 3T3-C2 cells, a subclone of Swiss 3T3 cells that does not undergo adipocyte differentiation, did. We conclude that interaction between mammary epithelium and other specific nonepithelial cells markedly influences the acquisition of hormone sensitivity of the epithelium and hormone- dependent differentiation.

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Selected References

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  1. Andersen C. R., Larson B. L. Comparative maintenance of function in dispersed cell and organ cultures of bovine mammary tissue. Exp Cell Res. 1970 Jul;61(1):24–30. doi: 10.1016/0014-4827(70)90253-3. [DOI] [PubMed] [Google Scholar]
  2. Banerjee M. R. Responses of mammary cells to hormones. Int Rev Cytol. 1976;47:1–97. doi: 10.1016/s0074-7696(08)60086-8. [DOI] [PubMed] [Google Scholar]
  3. Burnette W. N. "Western blotting": electrophoretic transfer of proteins from sodium dodecyl sulfate--polyacrylamide gels to unmodified nitrocellulose and radiographic detection with antibody and radioiodinated protein A. Anal Biochem. 1981 Apr;112(2):195–203. doi: 10.1016/0003-2697(81)90281-5. [DOI] [PubMed] [Google Scholar]
  4. Ceriani R. L. Hormone induction of specific protein synthesis in midpregnant mouse mammary cell culture. J Exp Zool. 1976 Apr;196(1):1–12. doi: 10.1002/jez.1401960102. [DOI] [PubMed] [Google Scholar]
  5. Crow M. T., Olson P. S., Stockdale F. E. Myosin light-chain expression during avian muscle development. J Cell Biol. 1983 Mar;96(3):736–744. doi: 10.1083/jcb.96.3.736. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Emerman J. T., Enami J., Pitelka D. R., Nandi S. Hormonal effects on intracellular and secreted casein in cultures of mouse mammary epithelial cells on floating collagen membranes. Proc Natl Acad Sci U S A. 1977 Oct;74(10):4466–4470. doi: 10.1073/pnas.74.10.4466. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Enami J., Nandi S. A sensitive radioimmunoassay for a component of mouse casein. J Immunol Methods. 1977;18(3-4):235–244. doi: 10.1016/0022-1759(77)90177-6. [DOI] [PubMed] [Google Scholar]
  8. Enami J., Nandi S. Hormonal control of milk protein synthesis in cultured mouse mammary explants. Cell Differ. 1977 Oct;6(3-4):217–227. doi: 10.1016/0045-6039(77)90017-3. [DOI] [PubMed] [Google Scholar]
  9. Green H., Kehinde O. An established preadipose cell line and its differentiation in culture. II. Factors affecting the adipose conversion. Cell. 1975 May;5(1):19–27. doi: 10.1016/0092-8674(75)90087-2. [DOI] [PubMed] [Google Scholar]
  10. Green H., Rheinwald J. G., Sun T. T. Properties of an epithelial cell type in culture: the epidermal keratinocyte and its dependence on products of the fibroblast. Prog Clin Biol Res. 1977;17:493–500. [PubMed] [Google Scholar]
  11. Hata R. I., Slavkin H. C. De novo induction of a gene product during heterologous epithelial--mesenchymal interactions in vitro. Proc Natl Acad Sci U S A. 1978 Jun;75(6):2790–2794. doi: 10.1073/pnas.75.6.2790. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Juergens W. G., Stockdale F. E., Topper Y. J., Elias J. J. Hormone-dependent differentiation of mammary gland in vitro. Proc Natl Acad Sci U S A. 1965 Aug;54(2):629–634. doi: 10.1073/pnas.54.2.629. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Kratochwil K. Organ specificity in mesenchymal induction demonstrated in the embryonic development of the mammary gland of the mouse. Dev Biol. 1969 Jul;20(1):46–71. doi: 10.1016/0012-1606(69)90004-9. [DOI] [PubMed] [Google Scholar]
  14. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  15. Lee E. Y., Parry G., Bissell M. J. Modulation of secreted proteins of mouse mammary epithelial cells by the collagenous substrata. J Cell Biol. 1984 Jan;98(1):146–155. doi: 10.1083/jcb.98.1.146. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Levine J. F., Stockdale F. E. 3T3-L1 adipocytes promote the growth of mammary epithelium. Exp Cell Res. 1984 Mar;151(1):112–122. doi: 10.1016/0014-4827(84)90361-6. [DOI] [PubMed] [Google Scholar]
  17. Ono M., Oka T. The differential actions of cortisol on the accumulation of alpha-lactalbumin and casein in midpregnant mouse mammary gland in culture. Cell. 1980 Feb;19(2):473–480. doi: 10.1016/0092-8674(80)90522-x. [DOI] [PubMed] [Google Scholar]
  18. Ptashne K., Hsueh H. W., Stockdale F. E. Partial purification and characterization of mammary stimulating factor, a protein which promotes proliferation of mammary epithelium. Biochemistry. 1979 Aug 7;18(16):3533–3539. doi: 10.1021/bi00583a015. [DOI] [PubMed] [Google Scholar]
  19. Ray D. B., Horst I. A., Jansen R. W., Kowal J. Normal mammary cells in long term culture. I. development of hormone-dependent functional monolayer cultures and assay of alpha-lactalbumin production. Endocrinology. 1981 Feb;108(2):573–583. doi: 10.1210/endo-108-2-573. [DOI] [PubMed] [Google Scholar]
  20. Rubin C. S., Hirsch A., Fung C., Rosen O. M. Development of hormone receptors and hormonal responsiveness in vitro. Insulin receptors and insulin sensitivity in the preadipocyte and adipocyte forms of 3T3-L1 cells. J Biol Chem. 1978 Oct 25;253(20):7570–7578. [PubMed] [Google Scholar]
  21. Sakakura T., Sakagami Y., Nishizuka Y. Dual origin of mesenchymal tissues participating in mouse mammary gland embryogenesis. Dev Biol. 1982 May;91(1):202–207. doi: 10.1016/0012-1606(82)90024-0. [DOI] [PubMed] [Google Scholar]
  22. Shannon J. M., Pitelka D. R. The influence of cell shape on the induction of functional differentiation in mouse mammary cells in vitro. In Vitro. 1981 Nov;17(11):1016–1028. doi: 10.1007/BF02618428. [DOI] [PubMed] [Google Scholar]
  23. Suard Y. M., Haeuptle M. T., Farinon E., Kraehenbuhl J. P. Cell proliferation and milk protein gene expression in rabbit mammary cell cultures. J Cell Biol. 1983 May;96(5):1435–1442. doi: 10.1083/jcb.96.5.1435. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Talbot D. N., Yphantis D. A. Fluorescent monitoring of SDS gel electrophoresis. Anal Biochem. 1971 Nov;44(1):246–253. doi: 10.1016/0003-2697(71)90367-8. [DOI] [PubMed] [Google Scholar]
  25. Topper Y. J., Freeman C. S. Multiple hormone interactions in the developmental biology of the mammary gland. Physiol Rev. 1980 Oct;60(4):1049–1106. doi: 10.1152/physrev.1980.60.4.1049. [DOI] [PubMed] [Google Scholar]
  26. Wang C., Smith R. L. Lowry determination of protein in the presence of Triton X-100. Anal Biochem. 1975 Feb;63(2):414–417. doi: 10.1016/0003-2697(75)90363-2. [DOI] [PubMed] [Google Scholar]
  27. Wicha M. S., Lowrie G., Kohn E., Bagavandoss P., Mahn T. Extracellular matrix promotes mammary epithelial growth and differentiation in vitro. Proc Natl Acad Sci U S A. 1982 May;79(10):3213–3217. doi: 10.1073/pnas.79.10.3213. [DOI] [PMC free article] [PubMed] [Google Scholar]

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