Application Of Serum Proteomic Mass Spectra Analysis And Serum HER2 In Breast Cancer

Objective To analyze the characteristic of serum proteins mass spectra in healthy controls,breast benign tumor and breast cancer patients by using surface enhanced laser desorption ionization time of flight mass spectrometry(SELDI-TOF-MS)technology, and screen protein mass spectra , build diagnostic models. Further we evaluate the differential expression of serum proteins mass spectra grouped by different stages, different lymph node metabasis conditions and changes after operation;We analyze the relations between tissue HER2, serum HER2 and tissue HER2,serum proteins mass spectra in breast cancer patients to evaluate the dependablity of tissue HER2 status and serum HER2 as well as serum protein mass spectra.Methods Using SELDI technology and protein chip(CM10) to analyze mass spectra of serum samples including 113 cases of breast cancer,103 cases of breast benign tumor and 92 cases of healthy controls. Biomarker Pattern Software (BPS) was used to detect the protein peaks significantly different between them and establish a diagnostic pattern which was further valuated by a blind test. Further analyze the differential expression of serum proteins mass spectra grouped by different stages, different lymph node metabasis conditions and changes after operation.Using immunohistochemistry (IHC) to detect tissue HER2,and enzyme linked immunosorbent assay (ELISA) to detect serum HER2 level,analyze the relations between tissue HER2, serum proteins mass spectra and serum HER2 in breast cancer patients.Results Twelve significantly different protein peaks were found in serum samples between breast cancer patients and healthy controls,BPS choose three peaks(4179,2740,2947 Da) of them to build up a taxonomic tree model(model I) which can classify the two groups. Eleven significantly different peaks were found between breast benign tumor patients and healthy controls,BPS choose two peaks(4179,6442 Da) to build up a taxonomic tree model(model II) which can classify the two groups. Two significantly different peaks were found between breast cancer patients and breast benign tumor,sofeware choose two peaks(4179,6442 Da) to build up a taxonomic tree model(model III) which can classify the two groups.By combinated analyses of those three different protein mass spectras,we find out the peak 15952Da is significantly different between breast cancer group and healthy controls,and so is between breast cancer group and breast benign tumor group(breast cancer group value 12.00±5.42, breast benign tumor group value 6.13±3.31,healthy controls value 6.08±4.23). Peak 7985Da is significantly different in all three groups(breast cancer group value 10.01±3.75, breast benign tumor group value 6.09±2.35,healthy controls value 4.08±2.27),and rest of the peaks have not significant difference.We find ten significantly different protein peaks when compare Stage I breast cancer to healthy controls. No significantly different protein peaks were found between stageⅣand stageⅠ-Ⅲbreast cancer. Similarly no significantly different protein peaks were found between lymph node negative and lymph node positive breast cancer patients. Peak values of 2947,3272,7985,15952 Da tend to close to that of healthy controls,and peak 7783 Da continue to be at high level seven days and one month after operation. Peak values of 4179,5642,6442,6639,8705,13771 Da are constantly lower than normal peak values seven days and one month after operation.Serum HER2 level correlates to histological HER2 status,serum HER2 positive rate is higher in histological HER2 positive breast cancer than that of histological HER2 negative breast cancer,and parts of breast cancer patients where the primary breast cancer was designated HER2 negative by tissue testing,but who develop elevated serum HER2 levels in metastatic breast cancer (MBC).No significantly different protein peaks were found between histological HER2 positive and HER2 negative breast cancer patients yet.Conclusions (1)Significantly different protein peaks can be screened out in breast cancer, breast benign tumor patients and healthy controls using SELDI-TOF-MS technology. Protein peak 7985 Da may be a biomarker of breast cancer, breast benign tumor patients and healthy controls. And Protein peak 15952 Da may be a biomarker of breast cancer and non-cancer patients.(2)Significantly different protein peaks can be found seven days and one month after operation compared to preoperation. Protein peaks 2947,3272,7985,15952 Da maybe useful in monitoring recurrence after operation. (3)Serum HER2 level correlates to histological HER2 status, serum HER2 positive rate is higher in histological HER2 positive breast cancer than that of histological HER2 negative breast cancer,and parts of histological HER2 negative breast cancer were found to be elevated serum HER2 levels (4)No significantly different protein peaks are found between histological HER2 positive and HER2 negative breast cancer patients yet.