A Highly Sensitive Targeted Mass Spectrometric Assay for Quantification of AGR2 Protein in Human Urine and Serum

作者：Shi Tujin; Gao Yuqian; Quek Sue Ing; Fillmore Thomas L; Nicora Carrie D; Su Dian; Zhao Rui; Kagan Jacob; Srivastava Sudhir; Rodland Karin D; Liu Tao; Smith Richard D; Chan Daniel W; Camp David G II; Liu Alvin Y^*; Qian Wei Jun

来源：Journal of Proteome Research, 2014, 13(2): 875-882.

DOI：10.1021/pr400912c

• AGR2
• PSA
• prostate cancer
• PRISM-SRM
• human urine
• human serum

Anterior gradient 2 (AGR2) is a secreted, cancer-associated protein in many types of epithelial cancer cells. We developed a highly sensitive targeted mass spectrometric assay for quantification of AGR2 in urine and serum. Digested peptides from clinical samples were processed by PRISM (high pressure and high resolution separations coupled with intelligent selection and multiplexing), which incorporates high pH reversed-phase liquid chromatography (LC) separations to fractionate and select target fractions for follow-on LC-selected reaction monitoring (LC-SRM) analyses. The PRISM-SRM assay for AGR2 showed a reproducibility of <10% CV and limit of quantification (LOQ) values of similar to 130 pg/mL in serum and similar to 10 pg per 100 mu g of total protein mass in urine, respectively. A good correlation (R-2 = 0.91) was observed for the measurable AGR2 concentrations in urine between SRM and enzyme-linked immunosorbent assay (ELISA). On the basis of an initial cohort of 37 subjects, urinary AGR2/PSA concentration ratios showed a significant difference (P = 0.026) between noncancer and cancer. Large clinical cohort studies are needed for the validation of AGR2 as a useful diagnostic biomarker for prostate cancer. Our work validated the approach of identifying candidate secreted protein biomarkers through genomics and measurement by targeted proteomics, especially for proteins where no immunoassays are available.

• 出版日期2014-2