Table 2.
Proteomic studies for exosome biomarker discovery of prostate cancer.
| Potential Biomarker | Cohort | Isolation Method | Proteomics Method | Results | Reference |
|---|---|---|---|---|---|
| KLK2, KLK3/PSA, FOLH1, MSMB, ACPP, TGM4, NDRG1, NKX3-1, FKBP5, FAM129A, RAB27A, FASN, NEFH | DRE urine: prior to (n = 12) and after local treatment (n = 10); prior to RP (n = 3); benign prostate hyperplasia (n = 12) | Ultracentrifugation and density gradient centrifugation | Label-free | 3,686 proteins identified; significant reduction in prostate (cancer)-specific proteins and androgen-regulated proteins after local PCa treatment. | Dhondt et al. [85] |
| FABP5, Granulin, AMBP, CHMP4A, CHMP4C | DRE urine: discovery cohort (negative, n = 6; GS 6 PCa, n = 6; GS 8–9 PCa, n = 6); validation cohort: negative (n = 11); PCa (n = 18) | Ultracentrifugation | iTRAQ | 4,710 proteins identified; 5 associated with high GS. | Fujita et al. [87] |
| TM256, LAMTOR1, VATL, ADIRF, Rab proteins, proteasomal proteins |
Urine: PCa (n = 16); controls (n = 15) | Ultracentrifugation | Label-free | 1,644 proteins identified; 246 were differentially expressed with a focus list of 37 proteins. | Øverbye et al. [19] |
| Filamin A | Serum | Ultracentrifugation | Label-free | Filamin A as AA-specific biomarker. | Panigrahi et al. [86] |
| 22 unique for AA; 13 unique for Caucasian; 78 unique for Hispanic | Plasma: PCa (4 Caucasian, 4 AA, 4 Hispanic); healthy controls (n = 9) | ExoQuick (precipitation) | Label-free | 258 proteins identified; specific protein biomarkers identified for PCa patients in each ethnic group. | Turay et al. [92] |
| AKAP12, ITGB4, MSN, VCL | Cell culture medium: PC-3 cells and taxane-resistance PC-3 cells | Ultracentrifugation and affinity isolation | iTRAQ | 110 proteins detected; ITGB4 and VCL were associated with taxane-resistance in PC-3 cells. | Kawakami et al. [88] |
| MDR-1, MDR-3, Endophilin-A2, PABP4 | Discovery: cell culture median (sensitive and resistant DU145 cells); validation: serum from CRPC patients (3 resistant and 3 sensitive to docetaxel) | Ultracentrifugation and density gradient centrifugation | Label-free | 914 proteins identified; 4 proteins were associated with docetaxel resistance in DU145 cells. | Kharaziha et al. [89] |
| MFG-E8, integrins, MET, ROR1, ITIH4, NOTCH3, L1CAM, RAC1, ADAM9 |
Culture medium of DU145 PCa cell line compared to whole cell lysate | Density gradient centrifugation | SOMAscan array | ~100 proteins enriched in exosomes; NOTCH3, L1CAM, RAC1, and ADAM9 were confirmed by western blot. | Webber et al. [90] |
DRE: digital rectal exam; RP: radical prostatectomy; PCa: prostate cancer; GS: Gleason score; iTRAQ: isobaric tags for relative and absolute quantitation; AA: African American; CRPC: castration-resistant prostate cancer.