The increasing use of three-dimensional (3D) cell culture is because it reproduces in vitro results similar to in vivo results. Multicellular tumor spheroids generated in vitro exhibit important characteristics of avascular tumors, mainly with respect to tumor physiology and microenvironment. The interaction among cells in a tridimensional culture environment enhances cell differentiation and leads to luminal formation in some breast-derived cell cultures. The present work describes a method that permits luminal formation in breast adenocarcinoma cell (MCF-7)-derived spheroids in a 3D environment. In the proposed model, several relevant parameters, such as cell survival, apoptosis, autophagy, and E-cadherin expression, were analyzed to understand the organization of MCF-7 cells during different culture phases, including luminal and bud formation.