Activated β1 integrins in primary and metastatic human tumors.

<p>(A and B) Representative immunostaining of FFPE tissue sections for total β1 integrin (antibody 4B7R) and activated β1 integrin (antibody 9EG7) in primary and metastatic tumors. For detection and analysis of tumor cells, samples were stained with an antibody to pan-keratin (breast cancer) (A) or MART-1 (melanoma) (B). The breast cancer metastasis was from a lymph node and the melanoma metastasis was from the abdominal cavity. Primary and metastatic tumors were from different patients. Note that in the primary breast tumor and metastatic melanoma, activated β1 integrins were observed in some connective tissue cells as well as in tumor cells. Fluorescence images of primary and metastatic tumors were processed identically. (C) Box plot showing β1 integrin activation in primary (n = 50) and metastatic (n = 26) melanomas in a tissue microarray. The proportion of areas with activated β1 integrin to total β1 integrin within MART-1 positive melanoma cells was analyzed with Volocity software. Statistical analysis was performed by Mann-Whitney U test (Outliers, values outside of 1.5 X interquartile distance from the quartiles, are indicated by an X).