Derivation and expansion of human epithelial mammary glands colonies for breast reconstruction

In this thesis we leveraged in vitro regenerating mammary gland as an experimental strategy aiming at improving our understanding of mammary gland biology and, in perspective, to design innovative strategies in regenerative medicine. Specifically, we investigated the reprogramming of mature breast cells, explanted from adult patients undergoing reduction mastoplasty, into cells similar to mammary stem cells, capable of regenerating tissue and adapting to new environments. Using these samples, we isolated specific cell types and induced them to revert to a more primitive, regenerative state. These reprogrammed cells were then grown in lab-based 3D conditions to see if they could form organoids, an indicator of regenerative potential. We found that these adult cells could indeed regain some regenerative abilities, forming multiple generations of organoids. However, the shape and structure of these colonies became less organized over time, and the results varied between individuals. Overall, our findings suggest that adult breast cells can regain plasticity, offering a potential avenue for biologically compatible breast tissues and for proof-of-principle investigation on mammary gland biology.