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

Abstract

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.

The Contribution of MMP-7 Promoter Polymorphisms in Renal Cell Carcinoma

“…Our findings suggest that these two MMP-7 genotypes may not play a critical role in mediating susceptibility to RCC. The rational for focusing on the MMP-7 promoter polymorphisms, A-181G and C-153T, is based on the phenotypic findings which report that MMP-7 may serve as a promising serum marker for the prediction of RCC (19)(20)(21). In 2008, Sarkissian and his colleagues examined the serum levels of MMP-7 among healthy subjects, control patients and 30 RCC patients and found that MMP-7 was significantly higher in RCC patients than the other two groups (19).…”

“…The rational for focusing on the MMP-7 promoter polymorphisms, A-181G and C-153T, is based on the phenotypic findings which report that MMP-7 may serve as a promising serum marker for the prediction of RCC (19)(20)(21). In 2008, Sarkissian and his colleagues examined the serum levels of MMP-7 among healthy subjects, control patients and 30 RCC patients and found that MMP-7 was significantly higher in RCC patients than the other two groups (19). In the same year, Ramankulov and his colleagues reported that similar MMP-7 levels were found in controls and patients with non-metastatic RCCs , while MMP-7 serum levels were significantly elevated in metastatic RCCs.…”

“…The authors suggested that serum MMP-7 may serve as a marker of metastasis and poor prognosis but not as a diagnostic marker (20). In 2016, Niedworok and his colleagues' findings also showed elevated serum levels in metastatic compared to non-metastatic RCC cases (19). Thus, MMP-7, in addition to carbonic anhydrase IX, VEGF, IL-6 and CRP, may serve as a promising serum marker for the detection of metastasis and prediction of poor survival for RCC, similarly to other cancers including gastric (22), colorectal (23,24) and ovarian cancer (25).…”

Circulating Matrix Metalloproteinase-7: An Early or Metastatic Marker for Renal Cell Carcinoma?

“…We read with great interest the article by Sarkissian et al (1 ) reporting the identification of serum matrix metalloproteinase-7 (MMP-7) 1 as a marker for renal cell carcinoma (RCC). For the purpose of identification, the authors used sera from healthy individuals and RCC patients and combined 2-dimensional electrophoresis of an RCC cell-line supernatant and an immunoblotting procedure.…”

“…In contrast, the 95th percentile they observed in their control group (3.29 g/L vs our 3.35 g/L) suggested that these concentration differences did not exist in the healthy participants of the 2 studies. Because the same recombinant human MMP-7 was used as a calibrator in both assays, it can be assumed that MMP-7 forms possibly typical for RCC patients are more sensitively detected by the assay of Sarkissian et al (1 ) than by the R&D MMP-7 assay we used. Different assay designs including the use of the mentioned specific antibodies could affect the assay sensitivity, but autoantibodies to pro-MMP-7 occurring in sera of RCC patients (1 ) could also interfere with measurement of MMP-7.…”