Adenoviral-mediated gene transfer into primary human and mouse mammary epithelial cells in vitro and in vivo

Primary mammary epithelial cells from both the human and mouse mammary glands can be genetically altered under a variety of situations using the replication-defective adenoviral vector containing a marker gene encoding the E. coli β-galactosidase. Primary human and mouse mammary epithelial cells in monolayer culture and in three-dimensional collagen gel culture systems were transduced by adenovector at high efficiency. Successful gene transfer was also accomplished in situ and in vivo. In the mouse mammary gland, anatomically restricted gene transfer and expression was demonstrated by micro-injection of adenoviral vector directly into the main duct of the mammary gland. Injection of adenoviral vector directly into the human mammary tissues from reduction mammoplasty specimens, into the mouse mammary gland-free fat pad containing the previously transplanted dissociated human mammary epithelial cells, and intratumorally into the human breast cancer xenografts in nude mice, all resulted in successful gene transfer to human mammary epithelial cells. High efficiency introduction of genetic material into primary mammary epithelial cells is important in the study of mammary carcinogenesis and potentially for gene therapy of human breast cancer.