title: CPA4 is a promising diagnostic serum biomarker for pancreatic cancer.
abstract: CPA4 belongs to a member of the metallocarboxypeptidase family, and its expression in pancreatic cancer samples and clinical significance are still not investigated until now. In this study, we aimed to evaluate the level of CPA4 in pancreatic cancer samples and study its clinical implications as a diagnostic marker for pancreatic cancer. The levels of CPA4 in pancreatic cancer tissues and serum samples were measured by immunohistochemistry (IHC) and enzyme-linked immunosorbent assay (ELISA), respectively. Among 150 pancreatic cancer tissues examined, 86.7% (130/150) of cases showed positive staining for CPA4. Clinicopathological relevance analysis showed that CPA4 expression was correlated with advanced clinical stage and lymph node metastasis. Also, we found that the levels of CPA4 in serum samples were significantly high in cases whose expression was also high in paired tissue samples (N=50). In a larger sample set, we found that serum CPA4 in pancreatic cancer patients was significantly higher than for healthy controls (P<0.05). In addition, high serum CPA4 was significantly associated with the TNM stage, Lymph node involvement and distant metastasis. At a cutoff value of 0.3 ng/ml, CPA4 might be a better diagnostic biomarker of pancreatic cancer than CA199. In conclusion, CPA4 overexpression is associated with pancreatic cancer progression, and it might be a potential diagnostic serum marker for pancreatic cancer.
authors.affiliation: State Key Laboratory of Molecular Oncology, Cancer Hospital, Chinese Academy of Medical Sciences, Peking Union Medical CollegeBeijing 100021, P. R. China; Department of Pharmaceutical Sciences, University of MichiganAnn Arbor, MI 48109, USA.
authors.forename: Lichao
authors.initials: L
authors.lastname: Sun
authors.affiliation: Department of Pharmaceutical Sciences, University of Michigan Ann Arbor, MI 48109, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Burnett
authors.affiliation: The Department of Abdominal Surgical Oncology Cancer Hospital, Chinese Academy of Medical Sciences (CAMS) Beijing 100021, P. R. China.
authors.forename: Chunguang
authors.initials: C
authors.lastname: Guo
authors.affiliation: The Department of Abdominal Surgical Oncology Cancer Hospital, Chinese Academy of Medical Sciences (CAMS) Beijing 100021, P. R. China.
authors.forename: Yibin
authors.initials: Y
authors.lastname: Xie
authors.affiliation: Department of Hematology and Oncology, Children's Hospital of Soochow University Suzhou 215005, Jiangsu, P. R. China.
authors.forename: Jian
authors.initials: J
authors.lastname: Pan
authors.affiliation: State Key Laboratory of Molecular Oncology, Cancer Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College Beijing 100021, P. R. China.
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Molecular Oncology, Cancer Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College Beijing 100021, P. R. China.
authors.forename: Yuliang
authors.initials: Y
authors.lastname: Ran
authors.affiliation: Department of Pharmaceutical Sciences, University of Michigan Ann Arbor, MI 48109, USA.
authors.forename: Duxin
authors.initials: D
authors.lastname: Sun
keywords: CPA4; ELISA; immunohistochemistry; marker; pancreatic cancer