Increased serum level of GRS antigen as a novel diagnostic biomarker for renal cell carcinoma

Abstract

Background: There is a lack of reliable and specific markers for the diagnosis of early stage renal cell carcinoma (RCC). In renal cell carcinoma, CDH 6 expression level is increased. Furthermore, in our previous study, we founded that CDH 6 is a functional receptor for GRS (Glycyl-tRNA synthetase). This study observed level of serum GRS antigen and antibody as detection biomarkers in renal cell carcinoma. Methods: Serum samples from patients with renal cell carcinoma were examined for serum GRS antigen and antibody level by an enzyme-linked immunosorbent assay (ELISA). The receiver operating characteristic (ROC) curves were used to determine area under the curve (AUC), sensitivity, specificity, and cut-off value for prediction of RCC. Results: The level of serum GRS antigen was significantly higher in RCC patients than in normal human serum (NHS) (RCC 34.11 ± 9.76 ug/ml

NHS 19.22 ± 6.06 ug/ml

p < 0.0001). The AUC for GRS antigen was 0.900 (95% CI = 0.840-0.960, p < 0.0001). The sensitivity and specificity for GRS antigen detection method were 91.0 % and 75.0 %, respectively, when cut-off value of GRS antigen was 22.86 ug/ml. Conclusions: Serum antigen level of GRS was significantly associated with RCC. GRS antigen may be a good novel biomarker or drug target for renal cell carcinoma.