The Primary Research Of Serum Tumor Biomarkers In Breast Cancer By Proteomics

Objective: Breast cancer is one of the most common malignant tumors in women with a high morbidity and mortality.According to statistics,among the national women in 2015,it is reported that there were about 269,000 new cases of breast cancer,accounted for 15% of the morbidity in malignant tumor of female.And there were about 70,000 breast cancer deaths on a national scale,accounted for 7% of the mortality in malignant tumor of female.Risk factors of breast cancer are diverse,such as age?familial inheritance?ionizing radiation?breast feeding factors?body weight?dietary habits,psychosocial factors.However,it is still unclear of the pathogenesis and molecular mechanism of breast cancer,because of lacking of effective diagnostic markers and methods.The later the breast cancer is confirmed,the more difficult it is to treat and the lower survival rate are.Therefore,it is important for clinical and social to screen early diagnostic biomarkers of breast cancer and further to find targeted therapeutic drug targets.Proteomics can be used to examine the different protein expression in diverse cell and tissue samples under different pathological and physiological conditions to classify and identify of the interested proteins,and further analyze protein function.The serum cases of healthy people,breast cancer patients and patients with benign breast disease were collected,then establish 2-DE maps of serum samples of healthy people,breast cancer and benign breast disease by proteomics technology,screen for differentially expressed proteins by PDQuest software and further analyze and identify differentially expressed proteins in healthy people ? breast cancer and benign breast diseases by MS technology,which establishes the foundation of screening and identifying new molecular diagnostic markers of breast cancer in the early stage and provides the experimental basis for further exploring the role of these key proteins and revealing the molecular basis of the occurrence and development of breast cancer.Methods: Collecting separately 10 serum cases of breast cancer and benign breast disease from the affiliated hospital of southwest medical university,and collecting 10 serum cases of healthy people from physical examination center.The specimens can be divided into three groups:(1)health group and breast cancer group;(2)benign breast disease group and breast cancer group;(3)health group and benign breast disease group.Protein spots were separated by two-dimensional electrophoresis and identified differentially expressed proteins by matrixassisted laser desorption ionization-time of flight-mass spectrometry.Finally,collecting separately 4 serum cases of healthy people and breast cancer from the affiliated hospital of southwest medical university and verifying differentially expressed proteins by western blot.Results: The 2-DE maps of serum of healthy people?breast cancer and benign breast disease were established,22 differentially expressed proteins were analyzed by PDQuest software.Took the healthy group as the reference in(1)group,there were 18 protein spots(1-7?9-19)with up-regulated,and 4 protein spots(8?20-22)with down-regulated in breast cancer group.Took the benign breast disease group as the reference in(2)group,there were 7 protein spots(6?15-17?20-22)with up-regulated,and 15 protein spots(1-5?7-14?18-19)with down-regulated in breast cancer group.Took the healthy group as the reference in(3)group,there were 19 protein spots(1-9,10-19)with up-regulated,and 3 protein spots(20-22)with down-regulated in benign breast disease group.22 protein spots were sampled and detected by mass spectrometry.Finally,6 differentially expressed proteins related with breast cancer were identified successfully,the proteins were confirmed by the database,named as ankyrin-3 isoform x7?keratin,type I cytoskeletal 9?dystonin,isoform CRA_b?microtubule-actin cross-linking factor 1 isoform 4 ? nesprin-2 isoform X11 ? Dynein heavy chain 10,axonemal isoform X9.We find that the concentration of Keratin-9 in breast cancer group compared with the healthy group show a trend of increase by western blot,the result consistent with the proteomics.Conclusion:The 2-DE maps of serum of healthy people?breast cancer and benign breast disease were established,The 6 differentially expressed proteins in healthy group?breast cancer group and benign breast disease group were screened,they can be potential candidate biomarkers for diagnosis of breast cancer,and we find that the concentration of Keratin-9 in breast cancer group compared with the healthy group show a trend of increase by western blot,the result consistent with the proteomics.All the result provides the experimental basis for the next step further to study the effect of the above key proteins and reveals the molecular basis of breast cancer development.