Biomedical subjects

G Feriotto

Publications and source records attributed to G Feriotto.

59 records · Page 4Linked to original sources

PubMedDate not supplied

DNA elements target of transcriptional factors are not restricted to long terminal repeat of human immunodeficiency virus.

In this report we show that signals for transcriptional factors are not restricted to the HIV-1 LTR, but are present throughout the HIV-1 genome. Furthermore, we identified a sequence, AGAACAGATG, highly homologous to the X-box of class II MHC genes and located within the tat-IVS/env region of HIV-1. Double stranded oligonucleotides mimicking the HIV-1 region containing AGAACAGATG were synthesized and band shift experiments were performed demonstrating that this HIV-1 genomic region binds nuclear proteins. We further demonstrate that the binding of nuclear factors to this tat-IVS/env HIV-1 sequence is competed for, in the band-shift assay, by the highly homologous X-box of the promoter of the human HLA-DR alpha gene. The presence in the HIV-1 genome of DNA sequences homologous or identical to regulatory sequences of cellular genes represents a potential mechanism of predation of DNA elements recognized by DNA binding proteins.

Base Sequence↗

PubMedDate not supplied

Binding of nuclear factors to the IFN-gamma consensus sequence of the human HLA-DR alpha gene: effects of IFN-gamma on tumor cell lines.

The binding of nuclear proteins from human tumor cells to synthetic double stranded oligonucleotides mimicking upstream regions of the HLA-DR alpha gene was studied. As the HLA-DR alpha gene is inducible by interferon(IFN)-gamma, nuclear extracts were also purified from IFN-gamma treated cells. Our data indicate that a) nuclear binding proteins (named IFN-gamma-B3 and Z-B1/B2) are detectable, specific for the IFN-gamma and Z boxes of the human HLA-DR alpha gene; b) both IFN-gamma-B3 and Z-B1/B2 are present in HLA-D negative cell lines and c) the content of IFN-gamma-B3 and Z-B1/B2 is not modulated by IFN-gamma treatment. These data suggest that the presence in the nuclear compartment of these factors, presumably necessary for the correct regulation of the HLA-DR alpha gene, is not sufficient to explain its differential constitutive and induced expression in a variety of in vitro cultured cell lines of different lineage.

Base Sequence↗

PubMedDate not supplied

Effects of the proteinase inhibitor tetra-p-amidinophenoxyneopentane on in vitro adhesion and invasiveness of tumor cells.

Some of the biological processes which enhance the metastatic capacity of tumor cells are associated with the activation of proteinases. In this paper we examined the effects of aromatic polyamidines on "in vitro" invasiveness of tumor cell lines. In addition to their antiproteinase activity, aromatic polyamidines exhibit antiproliferative activity toward tumor cell lines and inhibit expression of specific oncogenes. The results obtained show that the aromatic polyamidine TAPP-Br does not affect attachment, but inhibits the "in vitro" invasiveness of tumor cells cultured on a reconstituted basement membrane composed by laminin, type IV collagen, entactin, heparan sulphate proteoglycans. Our data suggest that this and related compounds should be further studied as experimental antitumor agents.

Amidines↗

PubMedDate not supplied

New synthetic retinoids: effects on proliferation and differentiation.

Nine retinoid analogues were synthesized and their effects on cell proliferation and differentiation of tumor cell lines were analysed and compared with those of natural retinoids (retinoic acid, retinol, retinal). Our results demonstrate differential inhibitory effects of the synthetic retinoids on cell growth. This inhibitory activity of the synthetic retinoids was, in some cases, higher than that of retinoic acid and retinol. Natural and synthetic retinoids were found to be able to induce to a different extent erythroid differentiation of murine erythroleukemia cells and adipogenic conversion of Chinese Hamster FHO6N1-1 cells. Our data suggest that studies on the relationship between structure and biological activity could be approached by using the analysed synthetic retinoids.

Animals↗

PubMedDate not supplied

Effects of benzamidine derivatives on Ha-ras-1 mRNA accumulation in a Chinese hamster cell line transformed with the activated human T24 Ha-ras-1 oncogene.

Tetra benzamidine derivatives were found to inhibit proteinase activity, cell proliferation and accumulation of the Ha-ras-1 mRNA in the FHO6T1-1 Chinese Hamster cell line, transformed with the activated human T24-Ha-ras-1 oncogene. Di- and Tri-benzamidine derivatives were also found to be potent inhibitors of proliferation of FHO6T1-1 cells. These latter compounds could be proposed as useful substrates in the synthesis of drug-conjugated monoclonal antibodies or growth factors.

Amidines↗