Divide and Conquer: Isolating Cell Populations to Investigate How Breast Cancer Risk Factors Alter the Breast Microenvironment.

Breast cancer is a multifactorial disease with risk factors that are fixed or modifiable. Understanding how these risk factors interact within breast tissue may provide insight into how to improve interventions or chemoprevention strategies to reduce breast cancer incidence. Here we describe methods to utilize breast tissue from patients with defined risk factors undergoing reduction mammoplasty or prophylactic mastectomy to isolate epithelial cells, stromal cells, adipocytes, and macrophages to investigate how risk factors impact distinct cell populations within breast tissue. Following enzymatic digestion of breast tissue, adipocyte-enriched, stromal cell, and epithelial organoid fractions can be isolated. Using antibody-conjugated beads, further cell populations, such as macrophages, can be isolated for molecular analysis. These methods can be adapted to sequentially isolate other cell populations based on specific cell surface markers and are useful for small-sized breast tissue specimens.