Isolation of Resident Mammary Macrophages and Their Possible Role in Breast Cancer

Abstract

A novel tissue digestion and culture technique was used to enrich for macrophages and isolate cells from reduction mammoplasty and non-cancerous mastectomy tissue obtained from pre- and postmenopausal women. The effectiveness of the isolation procedure was tested with immunohistochemical techniques which characterized cells for the following proteins: CD 68 and Ham 56 (known markers of macrophage cells); keratin; and smooth muscle actin. The results of the immunohistochemistry verified the presence of macrophages in the cultures. Cell cultures were also tested for macrophage biological activity which was measured by the release of oxygen free radicals. Also studied was whether this response could be modified after cells were cultured with a reproductive hormone believed to affect the development of breast cancer. Estradiol (estrogen) showed high free radical production in this preliminary study and supports the immunohistochemical findings. This also suggests that macrophage response to stimulus is modified following the treatment with estradiol.