Received on ,
Accepted on ,

Proteomics and Protein Markers

Identification of Pro-MMP-7 as a Serum Marker for Renal Cell Carcinoma by Use of Proteomic Analysis

¹ Research and Development Department, Cezanne SAS, Parc Scientifique Georges Besse, Nimes, France
² Department of Biochemistry and Molecular Genetics, University Hospital Center-Pontchaillou Hospital, Rennes, France
³ Department of Clinical Laboratory, Val d'Aurelle-Paul Lamarque Cancer Institute, Montpellier, France
⁴ CNRS UMR6061 Genetics and Development, IFR 140, University of Rennes 1, Rennes, France
⁵ IGF, CNRS UMR5203, INSERM, U661, University of Montpellier 1, University of Montpellier 2, Montpellier, France

^* To whom correspondence should be addressed. E-mail: gsarkissian{at}cezanne.fr.

BACKGROUND: No validated renal cell carcinoma (RCC) marker is known for detection of asymptomatic disease in selected populations or for prognostic purposes or treatment monitoring. We identified immunogenic proteins as tumor markers for RCC by combining conventional proteome analysis with serological screening, and we investigated the diagnostic clinical value of such markers in serum.

METHODS: We studied the immunogenic protein expression profile of CAL 54, a human RCC cell line, by 2-dimensional electrophoresis combined with immunoblotting using sera from healthy donors compared with RCC patients. We developed a homogeneous, fluorescent, dual-monoclonal immunoassay for metalloproteinase 7 (MMP-7) and used it to measure MMP-7 in sera from 30 healthy donors, 30 RCC patients, and 40 control patients.

RESULTS: Pro-MMP-7 (29 kDa; pI 7.7) in the CAL 54 cell line secretome was an immunogenic protein reactive with RCC patient sera but not with control sera. The concentrations of pro-MMP-7 were increased (P <0.0001) in sera of RCC patients (median 7.56 µg/L; range 3.12–30.5 µg/L) compared with healthy controls (median 2.13 µg/L; range 0.17–3.5 µg/L). Serum pro-MMP-7 had a sensitivity of 93% (95% CI 78%–99%) at a specificity of 75% (59%–87%) for RCC in the samples tested.

CONCLUSION: Proteomics technology combined with serology led to the identification of serum pro-MMP-7 as a marker of RCC and represents a powerful tool in searching for candidate proteins as biomarkers.