1α,25‐Dihydroxy Vitamin D3 Modulation of HLA‐DR mRNA Induced by Gamma‐Interferon in Cultured Epithelial Tumor Cell Lines

Using three cultured epithelial tumor cell lines, we investigated and analyzed the effects of gamma-interferon (γ-IFN) and 1α,25-dihydroxy vitamin D3 (1,25-(OH)2D3) on the levels of HLA-DR (α) mRNA and HLA-DR (β) mRNA by Northern blot analysis. After treatment with γ-IFN alone, the levels of the mRNA increased. Treatment with both γ-IFN and 1,25-(OH)2D3 at the same time resulted in a significant decrease in the levels of mRNA in K-TL-1, IK-TL-2, and M-TL cells as compared to those induced by γ-IFN alone.