(A) The effect of coinjection of different cells on tumor weight. Normal myoepithelial cells (HME) significantly suppressed tumor weight, fibroblasts from normal breast (PBS) had no effect, and fibroblasts from breast tumors (PBTS) and rheumatoid arthritis synovium (RASF) increased tumor weight. (B) Histological and immunohistochemical analyses of MCFDCIS xenografts from coinjection experiments.
(C and D) The dominant effect of normal myoepithelial cells on tumor weight (C) and histology (D). Tumors resulting from the injection of MCFDCIS cells together with PBS+HME, PBTS+HME, and RASF+HME were significantly smaller and had DCIS histology compared to xenografts initiated from MCFDCIS cells coinjected with fibroblasts (PBS, PBTS, or RASF).
(E) Tumors of various coinjections were removed and analyzed 22 days after injection (original day 22). Reinjection of MCFDCIS cells isolated from these tumors (without any coinjection) resulted in DCIS-like xenografts (reinjected day 22).
Scale bars correspond to 100 μm in all panels.