The liver niche accelerates, while the lung niche restrains secondary spread of breast cancer.

Liver microenvironment promotes secondary breast cancer spread by enhancing metastasis, while lung microenvironment restricts this process, favoring local growth.

• Why it matters: Understanding how different organ microenvironments influence metastatic behavior is crucial for developing targeted therapies to prevent cancer dissemination and improve patient outcomes.
• What they did: The study used patient data, mouse models with barcode tracing, niche-labeling, and single-cell analysis to investigate cellular and molecular factors in liver and lung metastases, focusing on over 100 samples.
• The result: Findings identify BMP2-producing endothelial cells as key in the liver niche, promoting metastasis spread; inhibiting BMP2 signaling reduces secondary dissemination, offering new therapeutic avenues.