Downregulation of antigen presentation-associated pathway proteins in poor outcome triple-negative breast cancer patient tumors
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ABSTRACT: Triple-negative breast cancer (TNBC) is a heterogeneous subtype with varying disease outcomes. Tumor infiltrating lymphocytes (TILs) are frequent in TNBC and have been shown to correlate with outcome, suggesting an immunogenic component in this subtype. However, other factors, intrinsic to the cancer cells, may also influence outcome. To identify proteins and molecular pathways associated with recurrence in TNBC, 34 formalin-fixed paraffin-embedded (FFPE) primary TNBC tumors were investigated by global proteomic profiling using TMT-HILIC-LC-MS/MS. Approximately half of the patients were lymph node-negative and remained free of local or distant metastasis within 10 years follow-up, while the other half developed distant metastasis. Proteomic profiling identified >4000 proteins, of which 63 exhibited altered expression in primary tumors of recurrence versus recurrence-free patients. Importantly, down-regulation of proteins in the major histocompatibility complex (MHC) class I antigen presentation pathways were enriched, including TAP1, TAP2, CALR, HLA-A, ERAP1 and TAPBP, and were associated with significantly shorter recurrence-free and overall survival. In addition, proteins involved in cancer cell proliferation and growth, including GBP1, RAD23B, WARS and STAT1, also exhibited altered expression in primary tumors of recurrence versus recurrence-free patients. The association between the antigen-presentation pathway and outcome were validated in a second sample set of 10 primary TNBC tumors and corresponding metastases using proteomics and in a large public gene expression database of 249 TNBC and 580 basal-like breast cancer cases. Our study demonstrates that down-regulation of antigen presentation is a key mechanism for TNBC cells to avoid immune surveillance, allowing continued growth and spread.
INSTRUMENT(S): Q Exactive
ORGANISM(S): Homo Sapiens (human)
DISEASE(S): Breast Cancer
SUBMITTER: Martin Haar Pedersen
LAB HEAD: Henrik Ditzel
PROVIDER: PXD005544 | Pride | 2018-10-26
REPOSITORIES: Pride
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