Demethylating agent 5-aza-2'-deoxycytidine activates HLA-G expression in human leukemia cell lines

HLA-G is a non-classical HLA class I antigen primarily expressed in the extravillous cytotrophoblast. HLA-G can also be expressed at some pathological circumstances and may thus contribute to inhibition of efficient immune responses. Complex regulation of HLA-G expression also involves epigenetic mechanisms as DNA methylation. Here we demonstrate that treatment with demethylating agent 5-aza-2'-deoxycytidine (AdC) resulted in HLA-G transcription in 18 out of 20 examined leukemia cell lines. HLA-G protein synthesis was detected in 10 cell lines expressing significant level of HLA-G transcripts following AdC treatment.