In recent years,many new microtubule-associated proteins are found or studied extensively in the treatment of breast cancer.End-binding protein 1 (EB1)has the promotional effects on cell proliferation and enhances the carcinogenesis of breast cancer,and also can affect the chemosensitivity of the treatment. MAP7 domain-containing protein 3 (Mdp3)expresses in breast epithelial cells and plays an important role on the growth and metastasis.Nucleolar and spindle-associated protein (NuSAP)gene is up-regulated in breast cancer and is considered as a biomarker for breast cancer.Tau expression level has a strong correlation with estrogen receptor (ER),progesterone receptor (PR)and human epidermal growth factor receptor-2 (HER-2), and it remains controversial in the results of the effect of paclitaxel chemotherapy and hormone treatment.

Objective To seek differentially expressed proteins for human epithelial growth factorreceptor-2 (HER-2)negative and positive breast carcinoma through establishing proteins profiles,and to providenew prognostic markers and therapeutic targets for patients with breast cancer.Methods HER-2 positiveand negative breast cancer protein expression profiles were established using proteomic isobaric tags for relativeand absolute quantitation (iTRAQ)technology.Differences of protein expression were identified and parts ofdifferential expression proteins were analyzed by bio-informatics,including protein function annotation and GOclassification analysis and Kyoto Encyclopedia of Gene and Genome (KEGG)pathway analysis.Results Proteomicanalysis of breast cancer tissue with identified HER-2 positive and negative groups showed 4 999 differentiallyexpressed proteins by iTRAQ.Based on the criteria of the ratio of HER-2(+)/HER-2(-)≥3,119up-regulated proteins were identified in HER-2 positive group.Based on the criteria of the ratio of HER-2(+)/HER-2(-)≤0.5,47 down-regulated proteins were identified in HER-2 positive group.The results ofGO analysis showed that the molecular function,biological process and cellular composition of differentiallyexpressed proteins were complex between HER-2 positive and negative breast cancer.There were differences inthe distribution of up-regulated proteins and down-regulation of proteins.KEGG pathway analysis showed thatdifferentially expressed proteins involved in 168 signal pathways.Conclusion There are differentiallyexpressed proteins between HER-2 positive and negative breast cancer,which involve complex molecular func-tion,biological process and signaling pathway.

Objective To investigate the expression and significance of epithelial cell adhesion molecule (Ep-CAM) in breast cancer.Methods Twenty-three cases of breast cancer tissue samples and paired lymph node metastases confirmed pathologically were collected.Isobaric tags for relative and absolute quantitation (iTRAQ) proteomics technology was used to screen and identify the differentially expressed proteins between primary tumor and lymph node metastasis of breast cancer.The expression of Ep-CAM was detected by Western blotting in 4 cases of primary breast cancer tissues and paired lymph node metastases.And the expressions of Ep-CAM in 252 cases of breast lesions were detected by immunohistochemical method.Results Quantitative proteomic examination results showed that differentially expressed proteins existed in breast cancer primary tumor and lymph node metastasis,and the expression of Ep-CAM in metastatic lesions was higher than that in primary tumor.Western blotting results showed that the expression of Ep-CAM in metastatic lesions (1.46 ± 0.22) was higher than that in primary tumor (1.16 ± 0.09),which was consistent with the results of proteomic.The immunohistochemical results showed that the positive expression rate of Ep-CAM in lymph node metastasis tissues (93.16％,109/117) was significantly higher than that in primary breast cancer without metastasis (72.73％,64/88),and the difference was statistically significant (x2 =15.921,P =0.000).The positive expression rate of Ep-CAM in primary breast cancer with lymphatic metastasis (72.65％,85/117) was lower than that in paired lymph node metastases (P =0.001).Conclusion Ep-CAM is differentially expressed in primary tumor and lymph node metastasis of breast cancer,which may be related to the lymphatic metastasis of breast cancer.