Screening of Differential Mitochondrial Protein in Breast Cancer Cells Cultured In Vitro

Objective To screen differential mitochondrial protein by comparing the protein fingerprint of breast cancer cells cultured in vitro with that of normal breast cells,and lay a foundation of study on subcellular protein biomarker of breast cancer.Methods Mitochondrial proteins were extracted from breast cancer cell MDA-MB-231 and MCF-7 strains and normal breast cell HBL-100 strain,and analyzed for fingerprints by surface enhanced laser desorption ionization time-of-flight mass spectrometry(SELDI-TOF-MS).The results were analyzed by Biomarker Wizard Software,based on which differential mitochondrial proteins were screened,and the effect of dissolvent and long-term storage in frozen on the result analysis was evaluated.Results Nearly 200 protein peaks were observed in a relative molecular mass range of 2 000 to 100 000.Compared with that of HBL-100 cells,45 and 36 differential protein peaks were observed in MDA-MB-231 and MCF-7 cells(P 0.05) respectively.The expression levels of proteins with relative molecular masses of 9 200,13 800,14 000 and 22 500 in the two breast cancer cell strains decreased,while those with relative molecular masses of 10 000 and 11 600 increased.Triton X-114 at a concentration of 4‰ and storage in frozen for 3 ～ 6 months showed no effect on result analysis.Conclusion SELDI-TOF-MS may be used for rapid and sensitive detection of differential mitochondrial protein in breast cancer cells,which provided a novel route for study on subcellular protein biomarker of breast cancer.