Table 2.

Metastasis-Associated Proteins of Interest Identified by Protein Array Analysis of Lung-Conditioned Media^*.

Array Position (Figure 3)	Protein Name	Function/Association with Metastasis	References
39	bFGF, FGF2	Binds to CD44-bound proteoglycans for localized concentration and presentation to neighboring cells Mediates breast cancer migration, invasion, and metastasis	[33]
115	EREG	Member of epidermal growth factor family of growth factors Identified by Massagué and colleagues as a mediator of lung metastasis in breast cancer Mediator of pulmonary extravasation	[10,29]
117	SELE	CD44 ligand Adhesion molecule (soluble and surface-bound forms) Involved in transendothelial migration of tumor cells	[30]
303	SELL	CD44 ligand Adhesion molecule (soluble and surface-bound forms) Associated with the formation of a permissive metastatic microenvironment in the lung	[31,32]
333	OPN	CD44 ligand Identified by Massagué and colleagues as a mediator of lung metastasis in breast cancer Secreted and intracellular forms, well-established role in breast cancer cell migration and metastasis	[10,28]
346	SELP	CD44 ligand Adhesion molecule (soluble and surface-bound forms) Associated with the formation of a permissive metastatic microenvironment in the lung	[31,32]
429	uPA	Protease, interacts with COX-2 to mediate breast cancer motility/invasion COX-2 identified as a lung metastasis mediator by Massagué and colleagues	[10,27]
430	VCAM1	Adhesion molecule (soluble and surface-bound forms) Increased plasma levels of VCAM-1 associated with metastatic breast cancer	[40]
432	VEGFA	Growth factor, important in angiogenesis, therapeutic target for breast cancer	[41]

^*Data are derived from analysis of three separate protein arrays (N = 3) of lung-CM versus basal media.