Profiling protein markers associated with lymph node metastasis in prostate cancer by DIGE-based proteomics analysis.
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.
Pang
Jun
J
Department of Urology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou 510630, China.
Liu
Wei-Peng
WP
Liu
Xiao-Peng
XP
Li
Liao-Yuan
LY
Fang
You-Qiang
YQ
Sun
Qi-Peng
QP
Liu
Shao-Jun
SJ
Li
Ming-Tao
MT
Su
Zu-Lan
ZL
Gao
Xin
X
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
D014408:Biomarkers, Tumor; C493412:FABP5 protein, human; D050556:Fatty Acid-Binding Proteins; D009363:Neoplasm Proteins