[Identification and expression of cytochrome C in tumor-bearing mice model with neuroblastoma].

OBJECTIVE: To screen, identify and verify the serum specific protein of neuroblastoma in a tumor-bearing murine model and speculate about the source of cytochrome C. METHODS: NB cells (KP-N-NS) were inoculated subcutaneously into nude mice. And the sera samples of tumor-bearing mice (observation group, n = 14) and controls (control group, n = 25) were collected at 4 weeks to screen for and identify differentially expressed proteins. The method of surface-enhanced laser desorption-ionization time-of-flight mass spectrometry (SELDI-TOF-MS) was employed to screen the serum specific protein of neuroblastoma between two groups. Then serum protein targets were purified by high-performance liquid chromatography (HPLC) and identified by LC-MS/MS (LTQ). RESULTS: By comparing protein peaks among two sera groups, we identified the peak (11 609) showing significant differential expression between two groups. The expression of peak (11 609) was 3338.4 ± 1410.9 in observation group and 59.8 ± 40.7 in control group. This peak was identified as murine cytochrome C. CONCLUSION: Cytochrome C is a serum specific protein for neuroblastoma tumor and it comes from the apoptosis of non-tumor cells.