Protein Microarrays for Quantitative Detection of PAI-1 in Serum.
OBJECTIVE
Plasminogen activator inhibitor-1 (PAI-1), one crucial component of the plasminogen activator system, is a major player in the pathogenesis of many vascular diseases as well as in cancer. High levels of PAI-1 in breast cancer tissue are associated with poor prognosis. The aim of this study is to evaluate rigorously the potential of serum PAI-1 concentration functioning as a general screening test in diagnostic or prognostic assays.


METHODS
A protein-microarray-based sandwich fluorescence immunoassay (FIA) was developed to detect PAI-1 in serum. Several conditions of this microarray-based FIA were optimized to establish an efficacious method. Serum specimens of 84 healthy women and 285 women with breast cancer were analyzed using the optimized FIA microarray.


RESULTS
The median serum PAI-1 level of breast cancer patients was higher than that of healthy women (109.7 ng/ml vs. 63.4 ng/ml). Analysis of covariance revealed that PAI-1 levels of the two groups were significantly different (P<0.001) when controlling for an age effect on PAI-1 levels. However, PAI-1 values in TNM stage I-IV patients respectively were not significantly different from each other.


CONCLUSIONS
This microarray-based sandwich FIA holds potential for quantitative analysis of tumor markers such as PAI-1.
Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Clinical Laboratory, Peking University Cancer Hospital & Institute, Beijing 100142, China.
Xu
X
Ma
Qing-Yun
QY
Zhang
Breast cancer; Plasminogen activator inhibitor-1; Protein microarray; Serum