Insensitivity of cathepsin D gene to estradiol in endometrial cells is determined by the sequence of its estrogen responsive element.

In MCF7 cells, transcription of the lysosomal protease cathepsin D is stimulated by estrogens via a non-consensus estrogen responsive element (ERE). By contrast, in estrogen responsive Ishikawa endometrial cancer cells, the cathepsin D gene is unresponsive to estrogens. We now show that the transfected cathepsin D promoter, which can be induced by estrogens in several cell types, is insensitive in Ishikawa cells.

Characterization of the proximal estrogen-responsive element of human cathepsin D gene.

Cathepsin D, a lysosomal proteinase, is induced by estrogens in mammary cancer cells where its concentration is correlated with a higher risk of metastasis. Its gene expression is stimulated by estrogens in MCF7 cells, and we have shown that a short proximal promoter fragment from -365 to -122 is required for this induction. We now characterize, at -261, a nonconsensus estrogen-responsive element (ERE) (E2) with two differences in the distal half of its palindrome, which confers estradiol responsiveness to the heterologous Herpes simplex virus thymidine kinase promoter in transient transfection experiments.

Synergistic effect of interferon-gamma and tumor necrosis factor-alpha on antiviral activity and (2'-5') oligo (A) synthetase induction in a myelomonocytic cell line.

TNF was not observed to have an antiviral effect on either HL60 or U937 cells. However, it did significantly enhance interferon (IFN)-gamma-mediated antiviral activity in U937 cells. Treatment of U937 cells with IFN-gamma enhanced (2'-5') oligo (A) synthetase activity (2.

Binding and cross-linking of recombinant mouse interferon-gamma to receptors in mouse leukemic L1210 cells; interferon-gamma internalization and receptor down-regulation.

Recombinant E. coli-derived murine IFN-gamma (Mu-rIFN-gamma; 5 X 10(7) U/mg) was radiolabeled with 125I by the chloramine-T method without loss of its antiviral activity. The 125I-Mu-rIFN-gamma showed specific binding to L1210 cells.