Human leukocyte antigen G expression in breast cancer: role in immunosuppression

Cancer Biother Radiopharm. 2011 Apr;26(2):153-7. doi: 10.1089/cbr.2010.0924. Epub 2011 Apr 21.


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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Breast Neoplasms / genetics
  • Breast Neoplasms / immunology*
  • Breast Neoplasms / pathology
  • Cell Line, Tumor
  • Epithelial Cells / immunology
  • Epithelial Cells / pathology
  • Female
  • HLA Antigens / biosynthesis*
  • HLA Antigens / genetics
  • HLA Antigens / immunology*
  • HLA-G Antigens
  • Histocompatibility Antigens Class I / biosynthesis*
  • Histocompatibility Antigens Class I / genetics
  • Histocompatibility Antigens Class I / immunology*
  • Humans
  • Immune Tolerance
  • Immunohistochemistry / methods
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism


  • HLA Antigens
  • HLA-G Antigens
  • Histocompatibility Antigens Class I
  • RNA, Messenger