Angiopoietin-like protein 2 as a potential biomarker for colorectal cancer.

Colorectal cancer (CRC) is the third most common malignancy worldwide. Disease progression leads to its spread to other organs, such as the liver, and is associated with higher mortality rates. Early CRC detection is therefore crucial for maximizing the chances of complete cure. The measurement of serum-based tumor biomarkers has shown great potential for the detection of CRC. In this study, we investigated the feasibility of using angiopoietin-like protein 2 (ANGPTL2) as a candidate biomarker for CRC. We first investigated ANGPTL2 expression in 7 CRC cell lines, among which Colo320, NCC-CoCK-115P, Caco-2 and Colo205 exhibited comparatively high ANGPTL2 expression. The serum levels of ANGPTL2 in CRC patients (3.45±1.30 ng/ml) were higher compared with those in healthy controls (2.74±0.64 ng/ml) (P<0.05). A receiver operating characteristic analysis demonstrated that the diagnostic performance of ANGPTL2 was marginally lower compared with that of the established biomarker C-reactive protein, but higher compared with that of carbohydrate antigen 19-9. These results suggested that the simultaneous measurement of ANGPTL2, along with previously established serum biomarkers, may increase the likelihood of early detection of CRC.