Cell lines:
- By flow cytometry analysis, MCAM was found to be expressed by SK-BR-3 (>50% positive cells), MDA-MB-435 (>10% positive cells), MCF-7 (1-10% positive cells), but not by BT-20 breast cancer cells (BCC). Thus, expression of MCAM could not be a common phenomenon of cultured epithelial tumor cells (Putz E. et al., 1999).
- The phenotypic characteristics of 2 BCC lines (BC-H1 and BC-K1) established from bone marrow of patients with breast cancer were studied by immunocytochemistry, flow cytometry, and RT-PCR. Both cell lines expressed
E-cadherin,
vimentin, cytokeratins (including
component 18), alpha 5-,
alpha V-,
beta 1-, and
beta 3- integrin subunits,
ICAM-1, MCAM, LFA-3 (CD58), and
CD44s (but not
CD44v5,
v6,
v7/8). BC-H1 also expressed
ErbB2 (not found in BC-K1), and
MAGE-4 (but not MAGE-1, -2, -3/6, -12; BC-K1 was not tested). The expressed molecules might be potential candidates for novel therapeutic targets (Putz E. et al., 1999).
- Two BCC lines established from bone marrow of patients with breast cancer were found to express MCAM and ICAM-1 (Putz E. et al., 1999).
Tumors:
- The distribution and biological significance of MCAM was determined in normal, benign proliferative, and neoplastic breast ductal epithelium. MCAM expression was determined immunohistochemically in 14 of 14 (100%) normal breast epithelia and benign proliferative ductal epithelial lesions, whereas MCAM expression could only be focally detected in 12 of 72 (17%) breast carcinomas. Solid-phase cell adhesion assay revealed that breast carcinoma cells in culture express the ligand for MCAM. Transfection of MCAM cDNA into breast carcinoma cells induced a more cohesive cell growth pattern and established smaller tumors in immunocompromised mice than mock transfectants. In conclusion, MCAM is distributed throughout normal and benign proliferative mammary ductal epithelium, but it is frequently lost in carcinomas; it functions as a heterophilic cell-cell adhesion molecule in breast epithelium, and loss of MCAM expression in breast carcinoma might be an important step for tumor progression (Shih L.M. et al., 1997).
- 2 of 11 of infiltrating breast carcinomas, and 4 of 11 of germinomas were focally and weakly positive for MN-4, a mouse monoclonal antibody that specifically recognized a fixation-resistant epitope in the second extracellular (C2) domain of MCAM (Shih I.M. et al., 1998).
