The challenges of modeling hormone receptor-positive breast cancer in mice

Area of Science:

• Oncology
• Endocrinology
• Cancer Biology

Background:

• Estrogen receptor-positive (ER+) breast cancer (BC) constitutes 70-80% of all BC cases and relies on estrogen for growth.
• Endocrine therapies are standard for ER+ BC but face challenges with de novo or acquired resistance and late recurrence.
• Current in vivo models often fail to accurately represent ER+ BC, with most genetically engineered mouse models (GEMMs) being ER-negative and xenografts limited to a few cell lines.

Purpose of the Study:

• To highlight the critical role of the tumor microenvironment in ER+ cancer cells.
• To review the potential of the intraductal xenograft model for ER+ BC research.
• To address the urgent need for in vivo models that mimic human ER+ BC for studying resistance and recurrence.

Main Methods:

• Review of existing literature on ER+ breast cancer models.
• Discussion of the limitations of current genetically engineered mouse models (GEMMs) and xenograft models.
• Emphasis on the potential of the intraductal xenograft model.

Main Results:

• The tumor microenvironment is crucial for ER+ cancer cells.
• Existing in vivo models have significant limitations in recapitulating ER+ BC.
• The intraductal xenograft model shows promise for preclinical research.

Conclusions:

• There is a critical need for better in vivo models for ER+ breast cancer.
• The intraductal xenograft model offers a promising avenue for studying ER+ BC biology, endocrine resistance, and recurrence.
• Understanding the microenvironment is key to advancing ER+ BC research and patient care.