title: Analysis of HLA-G expression in breast cancer tissues.
abstract: 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.
authors.affiliation: Laboratory of Molecular Morphogenesis, National Cancer Research Institute, Genova, Italy. palmisano@vega.cba.unige.it
authors.forename: Giulio Lelio
authors.initials: GL
authors.lastname: Palmisano
authors.forename: Maria Pia
authors.initials: MP
authors.lastname: Pistillo
authors.forename: Paolo
authors.initials: P
authors.lastname: Fardin
authors.forename: Paolo
authors.initials: P
authors.lastname: Capanni
authors.forename: Guido
authors.initials: G
authors.lastname: Nicolò
authors.forename: Sandra
authors.initials: S
authors.lastname: Salvi
authors.forename: Bruno
authors.initials: B
authors.lastname: Spina
authors.forename: Gennaro
authors.initials: G
authors.lastname: Pasciucco
authors.forename: Giovanni Battista
authors.initials: GB
authors.lastname: Ferrara
mesh_terms: 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
chemical_list: D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I