HLA-G expression in basal cell carcinomas of the skin recurring after radiotherapy

Clin Exp Dermatol. 2005 Jul;30(4):422-5. doi: 10.1111/j.1365-2230.2005.01790.x.

Abstract

Basal cell carcinoma (BCC) of the skin represents the most common malignancy in the fair-skinned population worldwide. HLA-G is one of the molecules implicated in immunotolerance. To investigate the role of HLA-G in recurring BCCs, we constructed a tissue microarray containing 38 primary BCCs that underwent radiotherapy and 14 secondary BCCs recurring on the primary site after radiotherapy, and evaluated the HLA-G protein expression by immunohistochemistry. The HLA-G protein was most frequently expressed in aggressive sclerosing BCCs. Nodular BCC demonstrated the strongest HLA-G expression. Interestingly, tumor infiltrating mononuclear cells (TIMC) expressed the HLA-G molecule in BCCs that showed no recurrence. After comparing primary BCCs and BCCs relapsed after radiotherapy, we observed decreased HLA-G expression on tumor cells and the loss of HLA-G expression on TIMC in relapsed BCCs. After radiotherapy, immunobiology of BCC may change resulting in the down-regulation of HLA-G expression on tumor and on tumor-infiltrating cells.

MeSH terms

  • Carcinoma, Basal Cell / immunology*
  • Carcinoma, Basal Cell / radiotherapy
  • Follow-Up Studies
  • HLA Antigens / metabolism*
  • HLA-G Antigens
  • Histocompatibility Antigens Class I / metabolism*
  • Humans
  • Immune Tolerance
  • Immunoenzyme Techniques
  • Neoplasm Recurrence, Local / immunology*
  • Retrospective Studies
  • Skin Neoplasms / immunology*
  • Skin Neoplasms / radiotherapy

Substances

  • HLA Antigens
  • HLA-G Antigens
  • Histocompatibility Antigens Class I