Protein profiling of post-prostatic massage urine specimens by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry to discriminate between prostate cancer and benign lesions.
Post-prostatic massage urine specimens (PMUS) are expected to be rich in proteins originating from the prostatic acini. In this study, we created a PMUS bank consisting of 57 samples obtained from patients with biopsy-proven prostate cancer (PC) and 56 samples from subjects with biopsy-proven benign lesions to analyze protein profiles of PMUS by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS). Strong anion-exchange (Q10), weak cation-exchange (CM10) and immobilized metal affinity capture (IMAC30) ProteinChip Arrays were used for protein profiling. In PC samples, single-marker analysis detected 49 mass peaks that were significantly up-regulated and 23 peaks that were significantly down-regulated, compared with peaks obtained from benign lesion samples. To confirm reproducibility we performed additional three rounds of assay using CM10 chip with pH 4.0 binding buffer. Among these significant peaks, a peak of m/z 10788 was significant throughout all 4 rounds of assays. For hierarchical clustering analysis (HCA), we used the 72 peaks which revealed significant differences in single-marker analysis. The heat map discriminated PC from benign lesions with a sensitivity of 91.7% and a specificity of 83.3%. Therefore, SELDI-TOF MS profiling of PMUS can be applied to differentiate patients with PC from cancer-free subjects. However, further investigation is required to verify the usefulness of this method in clinical practice.
Okamoto
Akiko
A
Department of Urology, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan.
Yamamoto
Hayato
H
Imai
Atsushi
A
Hatakeyama
Shingo
S
Iwabuchi
Ikuya
I
Yoneyama
Takahiro
T
Hashimoto
Yasuhiro
Y
Koie
Takuya
T
Kamimura
Noritaka
N
Mori
Kazuyuki
K
Yamaya
Kanemitsu
K
Ohyama
Chikara
C
D000368:Aged; D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000652:urine*; D006801:Humans; D008297:Male; D008405:Massage; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000652:urine*; D040081:Protein Array Analysis / Q000379:methods; D040901:Proteomics / Q000379:methods; D012372:ROC Curve; D015203:Reproducibility of Results; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D014408:Biomarkers, Tumor