All authors reviewed the manuscript.. CI: 0.730C0.924). The microarray assay used in this study is a highly sensitive, accurate, and efficient assay for the determination of the AFP-L3%. Alpha-fetoprotein (AFP) produced by primary hepatic cancer is different from that generated by hepatitis, hepatic cirrhosis, and other benign hepatic diseases with respect to the carbohydrate chain. Compared with AFP generated by benign hepatic diseases, AFP generated by hepatic cancer has a much higher fucosylation index. Fucose has the GPDA characteristic of binding to agglutinin (LCA), which is isolated from (lentil) seeds. It has two subunits and a molecular weight of 46 kDa, and it forms a complex with sucrose. LCA is a useful component in affinity chromatography columns for the separation of glycoconjugates. AFP can be categorized into AFP-L1, AFP-L2, and AFP-L3 according to the affinity of the fucose residues for LCA. AFP-L3 has a high binding affinity for lectin LCA. AFP-L1 is mainly produced in benign hepatic diseases, AFP-L2 is mainly produced by pregnant women, and AFP-L3 is mainly produced in hepatocellular carcinoma (HCC)1,2,3. In 2005, the Food and Drug Administration (FDA) of the United States of America (USA) approved the use AFP-L3 as a tumor marker for primary hepatic cancer. AFP-L3 has high specificity and sensitivity for early diagnosis, differential diagnosis, evaluations of therapeutic effects, and prognosis monitoring4,5,6. Fucose is a methylated hexose that exists in carbohydrate chains of various glycoproteins in tissue and serum and is referred to as protein-bound fucose (P-bf). A fucose residue is present in the carbohydrate chain of AFP. This heteroplasmon is called fucosylated AFP (FucAFP), and its percentage of the total amount of AFP is called the fucosylation index (Fuol)7,8,9. The Fuol has important theoretical and clinical significance and can be used as an important indicator in hepatic cancer diagnostic and prognostic applications. AFP-L3 is an indicator of the biological behavior of HCC. The AFP-L3 levels correlate with patient survival and treatment. AFP-L3-positive HCC has the potential for rapid growth and early EPLG1 distant metastasis. Elevated AFP-L3 levels are considered to indicate treatment failure. The conventional serum fucose protein separation method involves the crossed affinity immunoelectrophoresis technique10,11, affinity blotting12,13, affinity chromatography14,15, a dual-site GPDA sandwich enzyme- linked immunosorbent assay16, a LiBASys tester (Chuo-ku Japan), the TASWako? i30 detection system technology (Richmond, VA USA), and the Hotgen Biotech glycosyl capture spin column pretreatment technology (Beijing, China). Of these components, the phytolectin affinity immunoelectrophoresis technique and the TASWako? i30 detection system technology have sophisticated requirements and use expensive reagents, thus restricting their popularization and application. Moreover, the glycosyl capture spin column makes the procedures more complicated because the sample treatment and detection are separated. In this study, a protein GPDA microarray method was developed to quantitatively detect AFP and/or FucAFP in biological samples and address the lack of quantitative detection technology for AFP and AFP-L3 in serum. The application of the protein microarray technique to AFP is not GPDA novel, but its application to AFP-L3 is novel. To our knowledge, a protein microarray method for detecting AFP-L3 has not been reported previously. This method is applicable both for the detection of AFP antigens in serum as well as for the general detection of other fucosylated proteins. Moreover, it has the advantages of being time-saving, inexpensive, accurate, and convenient. Results and Discussion All serum samples, including those from subjects with HCC and healthy controls, were detected by the AFP-L3% protein microarray assay. The serum AFP and AFP-L3 levels were markedly higher in patients with HCC than in the healthy individuals. The current AFP detection level adopts 20?ng/ml as the boundary17,18, with healthy individuals having AFP values of less than.
