Regulation of Stromal Cells by Sex Steroid Hormones in the Breast Cancer Microenvironment

Area of Science:

• Oncology
• Endocrinology
• Molecular Biology

Background:

• Breast cancer is a common hormone-dependent cancer, with estrogen receptor (ER) signaling a key target for endocrine therapy.
• Resistance to endocrine therapy remains a significant clinical challenge in ER-positive breast cancer.
• Androgens and androgen receptor (AR) signaling also play roles in breast cancer progression and endocrine resistance.

Purpose of the Study:

• To review the effects of sex steroid hormones, specifically estrogens and androgens, on stromal cells within the breast cancer microenvironment.
• To summarize current knowledge on how ER/AR signaling in breast cancer cells influences stromal cells.
• To highlight the direct impact of ER/AR signaling within stromal cells on breast cancer development.

Main Methods:

• Literature review of preclinical and clinical studies.
• Analysis of research on hormone receptor expression in breast cancer cells and stromal cells.
• Synthesis of findings on the cross-talk between hormone signaling pathways and the tumor microenvironment.

Main Results:

• Estrogen and androgen signaling in breast cancer cells modulate the tumor microenvironment.
• Stromal cells, including immune cells and fibroblasts, express ER and AR, influencing tumor progression.
• Hormone receptor expression in cancer cells correlates with the diversity of the stromal cell population.

Conclusions:

• Sex steroid hormones significantly impact the breast cancer tumor microenvironment by affecting stromal cells.
• Understanding ER/AR signaling in both cancer and stromal cells is crucial for developing effective breast cancer therapies.
• Targeting hormone signaling in the tumor microenvironment may overcome endocrine resistance.