Evaluation of the circulating level of fibroblast activation protein ? for diagnosis of esophageal squamous cell carcinoma.
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ABSTRACT: To evaluate whether circulating fibroblast activation protein ? (FAP?) could serve as a biomarker for the diagnosis of esophageal squamous cell carcinoma (ESCC), enzyme-linked immunosorbent assay (ELISA) was used to detect plasma FAP? in 556 participants including ESCC group, benign esophageal disease group, healthy controls and other cancer controls group. The levels of plasma FAP? were significantly decreased in ESCC patients (P < 0.001) and showed a positive correlation with HDL-C levels (R = 0.372, P < 0.001). The sensitivity and specificity of plasma FAP? were 56.1% and 85.6% based on the optimal cut-off (49.04 ng/ml, AUC = 0.714). The combination of FAP? and the traditional biomarkers (CEA, CYFR211 and SCCA) improved the sensitivity (41.5%) without compromising the specificity (95.0%). Contradictorily, the immunohistochemical staining revealed the overexpression of FAP? in stroma of ESCC tissues. So the source of soluble FAP? was further explored by qRT-PCR, Western blotting, ELISA and immunoprecipitation in fibroblast cell lines and mouse xenograft models. We found that the plasma FAP? was not correlated with the FAP? expressed in tumor, and the multi-organ might contribute to the circulating levels of FAP? including skeletal muscle, liver and bone marrow. These results indicated that the low plasma FAP? level might due to the systemic reaction to the presence of tumor and circulating FAP? level might be a potential indicator for diagnosing ESCC.
SUBMITTER: Liao Y
PROVIDER: S-EPMC5444725 | biostudies-literature | 2017 May
REPOSITORIES: biostudies-literature
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