Breast Cancer Tumor Growth and Metastasis

The human breast cancer cell line MDA-MB-231 was purchased from ATCC (Manassas, VA, USA). Animal experiments were approved by the Catholic University of Korea Animal Care and Use Committee (IACUC no. 2018-0172-01). MDA-MB-231 cells (5 × 10⁵) and MSCs from TB or BM (5 × 10⁵) were co-injected into mammary fat pads of immune-deficient NOD scid gamma (NSG) mice in a mixture with growth factor-reduced Matrigel (BD). Primary tumor volumes were measured as previously described (width × length × height × 0.52) [32 (link)]. Distant metastasis was analyzed by gross and microscopic analysis of organs by hematoxylin/eosin staining.