Identification of novel serum biomarkers in child nephroblastoma using proteomics technology.

To screen and identify serum biomarkers for nephroblastoma in children using surface-enhanced laser desorption/ionization (SELDI) and other proteomics technologies. The surface-enhanced laser desorption/ionization time of flight mass spectrometry (SELDI-TOF-MS) was used to identify biomarkers in 100 children with nephroblastoma and 30 gender and age-matched normal healthy children. There were 30 cases of pre-operative patients and 70 cases of post-operative patients. Differentially expressed serum proteins were screened. The target proteins were then separated, purified, and analyzed by multidimensional high performance liquid chromatography (HPLC). The peptide mass fingerprints (PMFs) of each protein were obtained after scanning with LC-MS/MS (LTQ). The proteins were identified using SEQUEST and the biological functions and characterizations of these proteins were analyzed with bioinformatic methods. Two differential proteins (m/z 6455.5, 9190.8) were obtained. According to SEQUEST, the molecular masses of this two proteins indicated that they were apolipoprotein C-I and haptoglobin, respectively. Expressions of the two proteins were lower in the pre-surgery group compared with the post-surgery and control group (P<0.01). In contrast, the expression of this two proteins were higher in the early stage than in the advanced stage of nephroblastoma. Apolipoprotein C-I and haptoglobin may be used as potential biomarkers to predict the degree of malignancy, therapeutic outcomes, and prognosis of nephroblastoma in children.