Analysis of HLA-G expression in breast cancer tissues.
Among the different mechanisms by which cancer can elude the immune system, alterations in the expression of human leukocyte antigen (HLA) class I molecules on tumor cells may play a crucial role by impairing the HLA molecules interaction with T and natural killer (NK) cells specific receptors. More recently, aberrant expression of HLA-G has been described in different tumor tissues in addition to HLA class I downregulation. The HLA-G molecule is a nonclassical HLA class I antigen selectively expressed by trophoblast and thymic epithelial cells. Several studies reported that the HLA-G function might represent an additional mechanism of tumor immune escape, mainly inhibiting NK and cytotoxic T-cell activity. Here we report the analysis of HLA-G expression both at RNA level by reverse transcriptase-polymerase chain reaction and at protein level by Western blot and immunohistochemistry in 25 breast cancer patient tissues. The aim of this study was to elucidate the HLA-G gene expression pattern in breast tumor tissues and correlate it with HLA class I alterations. Our results demonstrated that HLA-G molecules expression was never found even in a group of patients revealing HLA class I total loss, and that HLA-G is not expressed in breast cancer tissue with a low-tumor grade (G1-G2) and minimal stromal contamination.
Palmisano
Giulio Lelio
GL
Laboratory of Molecular Morphogenesis, National Cancer Research Institute, Genova, Italy. palmisano@vega.cba.unige.it
Pistillo
Maria Pia
MP
Fardin
Paolo
P
Capanni
Paolo
P
Nicolò
Guido
G
Salvi
Sandra
S
Spina
Bruno
B
Pasciucco
Gennaro
G
Ferrara
Giovanni Battista
GB
D015153:Blotting, Western; D001943:Breast Neoplasms / Q000276:immunology*; D005260:Female; D005805:Genes, MHC Class I; D006680:HLA Antigens / Q000032:analysis* / Q000235:genetics / Q000502:physiology; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000032:analysis* / Q000235:genetics / Q000502:physiology; D006801:Humans; D007150:Immunohistochemistry; D020014:K562 Cells; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I