Loss of transporter in antigen processing 1 transport protein and major histocompatibility complex class I molecules in metastatic versus primary breast cancer.
We studied by immunohistochemistry the HLA-allelic, beta 2-microglobulin, and TAP-1 expression in primary breast carcinomas and related lymph node metastases. Thirty-three of the primary tumors and 44% of the lymph node metastases had a complete HLA class I loss. The higher incidence of antigenic loss in metastatic tumors suggests that recognition of HLA class I antigens by the host immunity could have an important role in the metastatic evolution of breast cancer. We observed a simultaneous defective expression of all three components involved in HLA class I expression. Since the controlling genes of heavy chain and TAP-1 are located in different chromosome than beta 2-microglobulin, it could be that a common factor exists regulating HLA class I antigenic expression. Five of 25 (20%) primary and metastatic tumors from HLA-A2-positive individuals also had a selective loss. The high incidence of HLA class I loss in breast cancer patients shows that adjuvant immunotherapy to induce HLA class I expression could be of value in a subgroup of patients.
Kaklamanis
L
L
Nuffield Department of Pathology, John Radcliffe Hospital, Oxford, United Kingdom.
Leek
R
R
Koukourakis
M
M
Gatter
K C
KC
Harris
A L
AL
D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D018528:ATP-Binding Cassette Transporters / Q000032:analysis*; D001943:Breast Neoplasms / Q000276:immunology* / Q000473:pathology; D005260:Female; D015395:Histocompatibility Antigens Class I / Q000032:analysis*; D006801:Humans; D008285:Major Histocompatibility Complex; D009362:Neoplasm Metastasis; D001613:beta 2-Microglobulin / Q000032:analysis
D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D018528:ATP-Binding Cassette Transporters; D015395:Histocompatibility Antigens Class I; C073119:TAP1 protein, human; D001613:beta 2-Microglobulin