Researchers in this study wanted to understand why breast cancer risk and outcomes can differ between populations, particularly between women of different genetic ancestries. While many studies focus on tumor cells, this research looked at the stromal cells—the supportive cells surrounding breast tissue—to see whether differences in these cells might influence cancer development.
To investigate this, the researchers studied normal breast tissue samples and developed special cell lines from these tissues. They focused on a group of stromal cells that express specific markers (including PROCR, ZEB1, and PDGFRα), which they referred to as PZP cells. These cells behave similarly to stem-like support cells and can develop into different types of tissue depending on their environment.
The researchers found that these PZP cells were more abundant in the normal breast tissue of women of African ancestry compared to those of European ancestry. These cells were also able to interact with nearby epithelial (breast) cells, influencing their behavior and increasing signals linked to inflammation and cancer development.
Overall, the study suggests that differences in the normal breast tissue environment—especially in supportive stromal cells—may help explain variations in breast cancer risk and progression.
