title: Profiling protein markers associated with lymph node metastasis in prostate cancer by DIGE-based proteomics analysis.
abstract: Current predictive tools and imaging modalities are not accurate enough for preoperative diagnosis of lymph node metastatic prostate cancer (LNM PCa). Proteomic analysis is introduced to screen potential biomarkers for early detection of LNM PCa. In our initial study, protein samples from localized and LNM PCa as well as benign prostatic hyperplasia tissues were analyzed using two-dimensional fluorescence difference in gel electrophoresis (2-D DIGE) coupled with MALDI-TOF/TOF MS. We identified 58 proteins that were differentially expressed in the LNM PCa group relative to the localized PCa group. Six of these proteins, e-FABP5, MCCC2, PPA2, Ezrin, SLP2, and SM22, are functionally relevant to cancer metastasis. Expression of these proteins was therefore further validated in tissue samples from the original cohort and also from a larger, independent cohort of patients using real time PCR, Western blotting, and immunohistochemistry staining. In addition, the serum levels of e-FABP5 were also examined by ELISA. Relative to localized PCa tissues, LNM PCa tissues had increased expression of e-FABP5, MCCC2, PPA2, Ezrin, and SLP2 and decreased expression of SM22. Patients with LNM PCa had significantly higher levels of serum e-FABP5. This study presents evidence that increased expression of e-FABP5, MCCC2, PPA2, Ezrin, and SLP2 and decreased expression of SM22 are useful diagnostic markers for the existence of LNM PCa.
authors.affiliation: Department of Urology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou 510630, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Pang
authors.forename: Wei-Peng
authors.initials: WP
authors.lastname: Liu
authors.forename: Xiao-Peng
authors.initials: XP
authors.lastname: Liu
authors.forename: Liao-Yuan
authors.initials: LY
authors.lastname: Li
authors.forename: You-Qiang
authors.initials: YQ
authors.lastname: Fang
authors.forename: Qi-Peng
authors.initials: QP
authors.lastname: Sun
authors.forename: Shao-Jun
authors.initials: SJ
authors.lastname: Liu
authors.forename: Ming-Tao
authors.initials: MT
authors.lastname: Li
authors.forename: Zu-Lan
authors.initials: ZL
authors.lastname: Su
authors.forename: Xin
authors.initials: X
authors.lastname: Gao
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D014408:Biomarkers, Tumor / Q000378:metabolism*; D015153:Blotting, Western; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods*; D050556:Fatty Acid-Binding Proteins / Q000097:blood; D006801:Humans; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D011470:Prostatic Hyperplasia / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D040901:Proteomics / Q000379:methods*; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D014408:Biomarkers, Tumor; C493412:FABP5 protein, human; D050556:Fatty Acid-Binding Proteins; D009363:Neoplasm Proteins