To Screen Protein Spectrum Related To Curative Effect Of Neoadjuvant Chemotherapy Of Breast Cancer By SELDI Technology

OBJECTIVEThis study aims to apply surface enhanced laser desorption lonization time-of-flight mass spectrometry (SELDI-TOF MS) technology testing the spectrum change of tissue protein of breast cancer before and after neoadjuvant chemotherapy (NAC),in order to screen difference peak intensities related to curative effect of NAC. Further speculate the influence to NAC by different classifications of TNM staging, patient age, lymph node metastasis status and ER, PR, HER-2. Compare protein peak intensities between clinical effective group and invalid group in order to screen related protein spectrum with predictive value of curative effect.METHODSTissues of64patients were obtained by thick needle biopsy before NAC, Objects of study accepted FEC or ET scheme (Cyclophosphamide500mg/mz, Epirubicin Hydrochloride100mg/m2, Floxuridine500mg/m2;or Epirubicin Hydrochloride75mg/m2and Docetaxel80mg/m2, on the first day,repeated every3weeks) for3or4cycles, following which surgical interventions were taken. After the sampled packed, part of them were fast frozen by the liquid nitrogen and then freeze-stored in a refrigerator under80℃and the other part were fixed in formalin liquid for subsequent immunohistochemical study. Frozen breast cancer tissues were cut by scissors weighing right amount per piece and fully grinded in liquid nitrogen. Tissue proteins were extracted by protein ion kit, and then protein concentration detected by K5600. Tissue protein liquids were processed by a bioprocessor to get spectrums, which were analysed by the Biomarker wizard software to obtain protein peak intensities before and after NAC, which were divided into two groups according to TNM stage(Ⅱ andⅢ),age (<50and>50years old), lymph node metastasis (≤4and>4lymph nodes metastasis) and ER, PR, HER-2negative and positive. The data was statistical analysed by SPSS17.0. The curative effect of NAC was evaluated according to standard RECIST, follow which patients were divided into effective group and invalid group in order to screen related protein spectrum with predictive value of curative effect.RESULTSUsing Mann-Whitney U rank and test, SELDI-TOF MS analysis demonstrated that the intensities of7different protein peaks, i.e.5825.89Da,8949.50Da,11053.48Da,11652.02Da,17898.94Da,22250.63Da,38546.56Da were higher in samples after NAC than those before NAC. Different protein peaks of tissues before NAC were screened out between effective group and invalid group, i.e.5360Da,9089Da,10528Da,13445Da,15118Da,44065Da.Moreover,8949.50Da,17898.94Da and38546.56Da were detected statistically differences in classifications of TNM stage, age,lymph node metastasis status and ER, PR, HER-2. In the immunohistochemical study, we found ER, PR and HER-2were changed in18patients, which were compared with the other46patients. The results were that38546.56Da was different before chemotherapy and8949.50Da and17898.94Da had differences after chemotherapy between the two groups.CONCLUSION1. Different protein peaks related to NAC can be screened by SELDI technology, predictors of NAC can be obtained combined with clinical curative effect.2. Classifications of TNM stage, age, lymph node metastasis status and ER, PR, HER-2might influence NAC to a certain extent.3. The results of this study provide the basis for finding protein level evaluation standard of curative effect.