Mapping and Identification of the Urine Proteome of Prostate Cancer Patients by 2D PAGE/MS

Abstract

Proteome analysis of the urine has shown that urine contains disease-specific information for a variety of urogenital system disorders, including prostate cancer (PCa). The aim of this study was to determine the protein components of urine from PCa patients. Urine from 8 patients with clinically and histologically confirmed PCa was analyzed by conventional 2D PAGE. The MS identification of the most prominent 125 spots from the urine map revealed 45 distinct proteins. According to Gene Ontology, the identified proteins are involved in a variety of biological processes, majority of them are secreted (71%), and half of them are enzymes or transporters. Comparison with the normal urine proteome revealed 11 proteins distinctive for PCa. Using Ingenuity Pathways Analysis, we have found 3 proteins (E3 ubiquitin-protein ligase rififylin, tumor protein D52, and thymidine phosphorylase) associated with cellular growth and proliferation (p = 8.35 × 10−4 − 3.41 × 10−2). The top network of functional associations between 11 proteins was Cell Death and Survival, Cell-To-Cell Signaling and Interaction, and System Development and Function (p = 10−30). In summary, we have created an initial proteomic map of PCa patient's urine. The results from this study provide some leads to understand the molecular bases of prostate cancer.

Proteomics analysis of malignant and benign prostate tissue by 2D DIGE/MS reveals new insights into proteins involved in prostate cancer

“…Another important observation that deserves to be highlighted is that only three proteins with differential abundance identified in this study (ALB, GC, AZGP1), were also detected in urine of PCa patients . Among them, only vitamin D binding protein was found with differential abundance in urine samples with the same fold change as in this study .…”

Proteomics in Diagnosis of Prostate Cancer/ Протеомика Во Дијагноза На Простатниот Карцином

“…Moreover, five of the proteins associated with PCa in previous study [96] such as TYMP, ENDOD1, RFFL, CRYZL1 and ILF2 were also detected with differential abundance in this study. Nine proteins with differential abundances were acute phase response proteins and the expression pattern of 4 differed from the defined expression in the canonical pathway.…”

“…Lastly, levels of the proteins in tumor tissue may be unchanged compared to unaffected tissues, but because of altered processing, increased turnover and cell breakdown, the proteins may appear at increased concentrations in the circulation, as in the case of PSA. In our experience, from 28 proteins identified with altered abundance between PCa and BPH tissues (Davalieva et al, submitted) we have detected only 3 (ALB, GC and AZGP1) in the urine of PCa patients [96]. Among them, only vitamin D binding protein (GC) was found with differential abundance in urine samples [97] with the same fold change as in the study analyzing tissue.…”

“…In the most recent studies, our group also focused on identification of non-invasive biomarkers in urine with higher specificity than PSA. In the first preliminary study we have determined the protein components of urine from PCa patients by conventional 2-D PAGE [96]. The MS identification of the most prominent 125 spots from the urine map revealed 45 distinct proteins.…”

Proteomics analysis of urine reveals acute phase response proteins as candidate diagnostic biomarkers for prostate cancer

“…One hundred and thirty four spots showed statistically significant (p < 0.05) 1.8 fold variation or more in abundance. However, upon manual checking of the spot quality, the majority of the protein spots with differential abundance were either part of the most abundant protein in the urine, later identified as albumin [ 28 ], or were low quality spots. Therefore, only 41 spots were selected for further analysis (Figure 1 ).…”