CULTURE PLATFORMS, METHODS, AND USES THEREOF

The present invention relates to the fields of life sciences and cell and tissue cultures, especially 3D cultures. Specifically, the invention relates to a method of maintaining the presence or activity of a human or mouse estrogen receptor (ER) in a cell of an ex vivo mammary cell or tissue culture or in a cell of other hormone responsive cell or tissue culture. Also, the present invention relates to a method of maintaining a luminal epithelial phenotype and/or cell identity of a mammalian cell in an ex vivo cell or tissue culture. Still, the present invention relates to a 3D matrix or 3D medium comprising the matrix for ex vivo culture, wherein said 3D matrix or 3D medium comprises one or more mammalian cells or tissues embedded in said 3D matrix or 3D medium, and to a system for ex vivo culture, wherein the system comprises mammalian cells or tissues embedded in a 3D matrix or 3D medium comprising said matrix. Still furthermore, the present invention relates to use of the 3D matrix, 3D medium or system of the present invention e.g. for ex vivo culture of a mammalian cell, drug discovery methods, biomarker studies and/or estrogen receptor (ER) signaling studies.