XPNPEP2 Is Associated with Lymph Node Metastasis in Pca Patients
28 Pages Posted: 20 Feb 2019More...
In our previous study, a tumor-homing peptide, TMTP1, selectively targets to the highly metastatic tumors and its metastatic foci. Aminopeptidase P2(XPNPEP2) is a receptor for TMTP1 tumor-homing peptide. However, the biological and clinical significance of Aminopeptidase P2 in human cancers remains unknown. In this study, the high-density multiple organ tumor tissue array was employed for the profile of XPNPEP2 expression in human specimens. The results showed that XPNPEP2 was moderately expressed in the prostate, but significantly decreased in the prostate cancer. Moreover, XPNPEP2 acts synergistically with kallikrein during bradykinin production. Hence we used TCGA, IHC and Elisa to analyze the expression of XPNPEP2 in tissues and serum of prostate cancer patients. XPNPEP2 expression was lower in prostate cancer tissue than in normal prostate tissue, but was higher in Prostate cancer tissue with local invasion and LN metastasis than in tissue with localized Pca. Western blot clarified XPNPEP2 had a secreted form in the serum. Then the serum of 128 Pca patients along with 70 healthy males and 40 prostate hyperplasia patients were obtained for detecting serum XPNPEP2 levels. Serum XPNPEP2 levels in Pca patients with LN metastasis (142.7±14.40 ng/mL) were significantly higher than levels in Pca patients without LN metastasis (61.63±5.50 ng/mL) (P <0.01). An ROC analysis revealed that a combination of PSA and XPNPEP2 was more efficient than PSA or XPNPEP2 alone for predicting LN metastasis, especially for Pca patients with low serum PSA levels. In summary, serum XPNPEP2 levels when combined with PSA levels may result in increased sensitivity for predicting LN metastasis in Pca patients, especially for patients with low serum PSA levels.
Funding Statement: This work was supported by the National Natural Science Foundation of China (81802608; 81302249; 81202061, 86271600).
Declaration of Interests: The authors declare: "No."
Ethics Approval Statement: Ethical approval was obtained from the ethical management committees of Tongji hospital. All participants provided written informed consent before being sampled for our study.
Keywords: Biomarker, XPNPEP2, Prostate cancer, Lymph node metastasis
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