title: Human leukocyte antigen G expression in breast cancer: role in immunosuppression.
abstract: Human leukocyte antigen G (HLA-G) is an immunotolerant nonclassical major histocompatibility complex Class Ib molecule. It is expressed by trophoblastic placental cells during pregnancy to protect the fetus from maternal alloreactivity. HLA-G is overexpressed in tumors and involved in cancer immune evasion. Reverse transcription-polymerase chain reaction and immunohistochemistry (IHC) were used to examine HLA-G expression in normal mammary and breast cancer cell lines and normal and human breast cancer tissues. Reverse transcription-polymerase chain reaction confirmed that normal epithelial MCF-12A cells had no HLA-G mRNA expression, whereas cancer cell lines MCF-7, T47D, and MDA-MB-231 and NCI/Adr-Res had various levels of HLA-G mRNA expression. Twelve (12) normal and 38 breast cancer tissues were examined by IHC. Fifty-eight (58) percent (22/38) of cancers had medium to strong staining to HLA-G, whereas only 8% (1/12) of normal breast tissues had medium to strong staining, and the difference was significant (p < 0.05). HLA-G staining was found in the membranes and cytoplasm of cancer cells. In conclusion, breast cancer cells overexpress HLA-G mRNA and protein, and this probably contributes to immune evasion.
authors.affiliation: Elliott-Elliott-Head Breast Cancer Research and Treatment Center, Baton Rouge, Louisiana 70816, USA. relliott@eehbreastca.com
authors.forename: Robert L
authors.initials: RL
authors.lastname: Elliott
authors.forename: Xian P
authors.initials: XP
authors.lastname: Jiang
authors.forename: Jeffrey T
authors.initials: JT
authors.lastname: Phillips
authors.forename: Brian G
authors.initials: BG
authors.lastname: Barnett
authors.forename: Jonathan F
authors.initials: JF
authors.lastname: Head
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D045744:Cell Line, Tumor; D004847:Epithelial Cells / Q000276:immunology / Q000473:pathology; D005260:Female; D006680:HLA Antigens / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology*; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007108:Immune Tolerance; D007150:Immunohistochemistry / Q000379:methods; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I; D012333:RNA, Messenger