title: Differential protein profiling of renal cell carcinoma urinary exosomes.
abstract: Renal cell carcinoma (RCC) accounts for about 3% of all human malignancies and its incidence is increasing. There are no standard biomarkers currently used in the clinical management of patients with renal cell carcinoma. A promising strategy for new biomarker detection is comparative proteomics of urinary exosomes (UE), nanovesicles released by every epithelial cell facing the urinary space, enriched in renal proteins and excluding high-abundance plasmatic proteins, such as albumin. Aim of the work is to establish the protein profile of exosomes isolated from urines of RCC patient compared with control subjects. We enrolled 29 clear cell RCC patients and 23 control healthy subjects (CTRL), age and sex-matched, for urine collection and vesicle isolation by differential centrifugation. Such vesicles were morphologically and biochemically characterized and proved to share exosome properties. Proteomic analysis, performed on 9 urinary exosome (UE) pooled samples by gel based digestion followed by LC-MS/MS, led to the identification of 261 proteins from CTRL subject UE and 186 from RCC patient UE, and demonstrated that most of the identified proteins are membrane associated or cytoplasmic. Moreover, about a half of identified proteins are not shared between RCC and control UE. Starting from these observations, and from the literature, we selected a panel of 10 proteins, whose UE differential content was subjected to immunoblotting validation. Results show for the first time that RCC UE protein content is substantially and reproducibly different from control UE, and that these differences may provide clues for new RCC biomarker discovery.
authors.affiliation: Department of Health Sciences, Univ. of Milano-Bicocca, Via Cadore 48, 20900 Monza, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Raimondo
authors.forename: L
authors.initials: L
authors.lastname: Morosi
authors.forename: S
authors.initials: S
authors.lastname: Corbetta
authors.forename: C
authors.initials: C
authors.lastname: Chinello
authors.forename: P
authors.initials: P
authors.lastname: Brambilla
authors.forename: P
authors.initials: P
authors.lastname: Della Mina
authors.forename: A
authors.initials: A
authors.lastname: Villa
authors.forename: G
authors.initials: G
authors.lastname: Albo
authors.forename: C
authors.initials: C
authors.lastname: Battaglia
authors.forename: S
authors.initials: S
authors.lastname: Bosari
authors.forename: F
authors.initials: F
authors.lastname: Magni
authors.forename: M
authors.initials: M
authors.lastname: Pitto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D002292:Carcinoma, Renal Cell / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D055354:Exosomes / Q000378:metabolism*; D005260:Female; D006801:Humans; D007668:Kidney / Q000378:metabolism; D007680:Kidney Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D040081:Protein Array Analysis; D011506:Proteins / Q000032:analysis; D020543:Proteome / Q000032:analysis*; D040901:Proteomics
chemical_list: D015415:Biomarkers; D011506:Proteins; D020543:Proteome