Regulation of classical HLA class I genes in human choriocarcinoma cells by nuclear proteins binding to MHC class I regulatory elements.

Abstract

The regulation of classical HLA class I genes in choriocarcinoma have been reported. We determined whether four choriocarcinoma cell lines expressed classical HLA class I or HLA-G by a reverse transcription-polymerase chain reaction (RT-PCR) and studied the regulatory mechanism of classical class I using a gel mobility shift assay. NUC1 and SCH expressed classical class I but not HLA-G. GCH1 and Jar did neither. Nuclear protein binding to the class I regulatory element (CRE) was detected in NUC1 and SCH. Interferon-gamma augmented both classical class I expression and the DNA-protein complex in NUC1. The DNA-protein complex was not observed in GCH1, and Jar showed a CRE-binding protein with different electrophoretic mobility and binding affinity from that of SCH and NUC1. The CRE is one of the regulatory elements of classical HLA class I genes in choriocarcinoma cells.