３次元培養法を用いたホルモン依存性増殖の観察

抄録

The use of in vitro culture methods which faithfully reproduce the in vivo behavior of cells is expected to add further information for prediction of effectiveness of drugs used for treatment of mammary cancer. The conventional monolayer culture method, however, has not always been satisfactory in this respect. For example, only limited degrees of growth and differentiation of mouse mammary epithelical cells have been observed in vitro in response to mammogenic and lactogenic hormones. Analysis of physicochemical microenvironment surrounding the mammary epithelial cells suggested that extracellular matrix as well as chemical mediators produced by the stromal cells of the mammary gland may be the key factors for the hormone-responsiveness. Our studies led us to hypothesize that hepatocyte growth factor (HGF) may be the mammary stroma-produced environmental factor which mediates the growth of adjacent epithelial cells. Use of three-dimensional collagen gel matrix culture method further enabled us to observe the hormone-responsive growth as well as branching morphogenesis of mammary epithelial cells. In the absence of homornes in the culture medium, the cells underwent apoptosis. Similarly to the observations on mammary epithelial cells, ventral prostate epithelial cells of the mouse grew in response to androgens under the three-dimensional collagen gel culture conditions in the presence of HGF. These observations strongly support the hypothesis that three-dimensional culture conditions allow the cells cultured in vitro to behave as those in vivo. [J Physiol Sci. 2006;56 Suppl:S12]