Breast tissue showed two distinct aging patterns in mice
In one mouse model, cancer-linked gene and protein changes appeared at 11 and 19 months but not at 3 or 14 months.
Limit: Only five mice per age group in each model
Edited by Boris Djordjevic · AgingResearch.News
An animal experiment in female BL/6C57 and BL/6NZB mice compared aging in mammary glands, the milk-producing glands, with five mice per age group in each model. BL/6C57 glands aged progressively, while BL/6NZB glands showed two waves of change. In the latter, genes and proteins linked to breast cancer processes showed waves at 11 and 19 months, absent at 3 and 14 months.
Researchers also injected mouse cancer cells and measured tumors after three weeks. BL/6NZB glands supported tumor growth at 11 and 19 months, but not at 14 or 22–26 months. In BL/6C57 mice, tumor growth increased from 14 months onward. Separately, analyses of two breast cancer databases found that a pattern of gene activity identified in mice was more prominent in women diagnosed at ages 45 and 65.
Why it matters
Breast aging may contribute to breast cancer’s two age peaks, the authors suggest. The work also adds to evidence that aging does not always follow a steady course.
Caveats
The cancer-growth experiments used injected cancer cells, not naturally arising breast cancers. The human database associations do not establish that women’s breasts age in the same two patterns.
