Primary Studies On The Mechanism Of Glucocorticoid Receptor MRNA Decreasing In SMMC-7721 Cell Line During Heat Shock

GR and GRmRNA were decreased in tissues and in cultured cells during the heat shock response. The aim of this study is to understand the mechanism of GRmRNA decreasing in heat shock response.It has been proved that the expression of HSP70 was increased after human liver cancer SMMC-7721 cell line being cultured at 44 °C for 1 hour. The capability of [~3H]dexamethasone binding to GR was decreased in the mean time GR content decreased.We use SMMC-7721 cell line as a heat shock model to know why GRmRNA decreased during heat shock .Compared with the 18s rRNA , GRmRNA content was decreased during heat shock, and the content gradually increase afterwards.In situ hybridization was done with the RNA probes of GRmRNA intron and exon, and optical density of cells obtained with confocol microscopy was analyzed by computer. Results indicate that GR mRNA transcription was suppressed, GR pre-mRNA splicing was suppressed and GRmRNA degradation was speeded up in heat shock response.