Preliminary study on quantitative proteomic analysis of differentially expressed proteins in HER-2 posi-tive and negative breast cancer / 国际肿瘤学杂志

ABSTRACT

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.