ABSTRACT
OBJECTIVE: Prostate cancer (PC) is one of the principal causes of death among men. Steroid hormones are involved in normal prostate growth and carcinogenesis. The purpose of our study was to investigate the effects on PC risk of polymorphisms from three steroid hormone receptor genes: the androgen (AR), and the alpha (ESR1) and beta (ESR2) estrogen receptors. DESIGN AND METHODS: The study was performed on a Caucasian population of 1045 PC patients and 814 controls. Using a logistic regression model, the different alleles and genotypes from those polymorphisms were analyzed according to case/control status, the tumor aggressiveness, and the age at onset. RESULTS: A significant association between PC risk and the pooled 4/5, 5/6, and 6/6 genotypes of the GGGA repeat located in the first intron of ESR1 (odds ratio (OR)=3.00, 95% CI=1.32-6.82, P=0.008) was observed. When we stratified the cases, this association was confined to patients with a Gleason score of 2-4 (OR=8.34, 95% CI=2.91-23.91, P<0.0001) or late onset PC (OR=2.91, 95% CI=1.22-6.93, P=0.016). An association between a short AR CAG repeat (less than 17 repeats) was also observed among patients with late onset PC (OR=2.34, 95% CI=1.15-4.76, P=0.019). CONCLUSIONS: These findings suggest that the GGGA repeat from ESR1 and the CAG repeat from AR may be associated with risk of late onset PC.
Subject(s)
Adenocarcinoma/genetics , Estrogen Receptor alpha/genetics , Estrogen Receptor beta/genetics , Prostatic Neoplasms/genetics , Receptors, Androgen/genetics , Adenocarcinoma/metabolism , Aged , Aged, 80 and over , Case-Control Studies , DNA, Neoplasm/genetics , Estrogen Receptor alpha/metabolism , Estrogen Receptor beta/metabolism , Genetic Predisposition to Disease , Genotype , Humans , Male , Microsatellite Repeats , Middle Aged , Polymerase Chain Reaction , Polymorphism, Genetic , Prostatic Neoplasms/metabolism , Receptors, Androgen/metabolismABSTRACT
Hepatitis C virus (HCV) treatment is based on the association of pegylated alpha interferon (IFN-alpha) and ribavirin. To improve the level of sustained virological response to treatment, especially in patients infected with HCV genotype 1, new IFNs with improved efficacy and toxicity profiles may be developed. In this report, we show that, in the BM4-5 cell line harboring an HCV subgenomic replicon, a novel and naturally occurring human IFN-alpha17 variant, GEA007.1, which was discovered by using an original population genetics-based drug discovery approach, inhibits HCV genotype 1 RNA replication more efficiently than does IFN-alpha2b. Moreover, we show that complete viral clearance is obtained in BM4-5 cells after long-term treatment with GEA007.1, while HCV subgenomic RNA is still detected in cells treated with other IFN-alpha variants or with standard IFN-alpha2b. Eventually, we demonstrate that the better inhibitory activity of GEA007.1 compared to that of standard IFN-alpha is likely to be due to stronger and faster activation of the JAK-STAT signaling pathway and to broader expression of IFN-alpha-responsive genes in cells. Our results demonstrate a superior inhibitory activity of GEA007.1 over that of IFN-alpha2b in the HCV replicon system. Clinical trials are required to determine whether GEA007.1 could be a potent "next generation" IFN for the treatment of HCV infection, especially in nonresponders or relapsing patients infected with HCV genotype 1 who currently represent a clinical unmet need.
Subject(s)
Antiviral Agents/therapeutic use , Hepacivirus/drug effects , Interferon-alpha/therapeutic use , Replicon , Virus Replication/drug effects , Cell Line , Hepacivirus/genetics , Hepacivirus/physiology , Humans , Interferon alpha-2 , Interferon-alpha/genetics , Luciferases/metabolism , RNA, Viral/analysis , RNA, Viral/metabolism , Recombinant ProteinsABSTRACT
The antiviral and antiproliferative activities of human type I interferons (IFNs) are mediated by two transmembrane receptor subunits, IFNAR1 and IFNAR2. To elucidate the role of IFNAR1 in IFN binding and the establishment of biological activity, specific residues of IFNAR1 were mutated. Residues (62)FSSLKLNVY(70) of the S5-S6 loop of the N-terminal subdomain of IFNAR1 and tryptophan-129 of the second subdomain of IFNAR1 were shown to be crucial for IFN-alpha binding and signaling and establishment of biological activity. Mutagenesis of peptide (278)LRV in the third subdomain shows that these residues are critical for IFN-alpha-induced biological activity but not for ligand binding. These data, together with the sequence homology of IFNAR1 with cytokine receptors of known structure and the recently resolved NMR structure of IFNAR2, led to the establishment of a three-dimensional model of the human IFN-alpha/IFNAR1/IFNAR2 complex. This model predicts that following binding of IFN to IFNAR1 and IFNAR2 the receptor complex assumes a "closed form", in which the N-terminal domain of IFNAR1 acts as a lid, resulting in the activation of intracellular kinases. Differences in the primary sequence of individual IFN-alpha subtypes and resulting differences in binding affinity, duration of ligand/receptor association, or both would explain differences in intracellular signal intensities and biological activity observed for individual IFN-alpha subtypes.
Subject(s)
Interferon Type I/metabolism , Peptide Fragments/metabolism , Receptors, Interferon/metabolism , Amino Acid Sequence , Animals , Antibodies, Monoclonal/metabolism , Binding Sites, Antibody , Cell Line , Cell Membrane/genetics , Cell Membrane/metabolism , DNA Mutational Analysis/methods , Extracellular Space/genetics , Humans , Ligands , Lysine/genetics , Membrane Proteins , Mice , Models, Molecular , Molecular Sequence Data , Peptide Fragments/genetics , Protein Binding/genetics , Protein Isoforms/biosynthesis , Protein Isoforms/genetics , Protein Structure, Tertiary/genetics , Receptor, Interferon alpha-beta , Receptors, Interferon/biosynthesis , Receptors, Interferon/genetics , Receptors, Interferon/immunology , Sequence Homology, Amino Acid , Serine/genetics , Signal Transduction/genetics , Transfection , Tryptophan/genetics , Tyrosine/genetics , Valine/geneticsABSTRACT
OBJECTIVES: Prostate cancer is a very common hormone-related malignancy in Western countries. It is initially dependent on androgen stimulation but in vitro growth of prostate cancer cells are also dependent on estrogen. Our goal was to elucidate if some polymorphisms of estrogen receptor alpha gene might be associated with the risk of prostate cancer. METHODS: Using DHPLC techniques, each coding exon of the estrogen receptor alpha gene was screened for new polymorphisms in germline DNA from 96 healthy controls and 96 sporadic prostate cancer cases. Identified polymorphisms were then genotyped and their distribution compared between the two populations. RESULTS: Thirteen polymorphisms were identified. A difference was found in the distribution of one newly identified polymorphism, namely a GGGA repeat located in the first intron of the gene. The common wild type genotype consisted of two alleles with five GGGA repetitions (5/5 genotype). Indeed this 5/5 genotype was found in 294/296 controls (99.3%) and 285/294 patients (96.9%; OR, 4.6; 95% CI, 0.99-21.67). Among the nine patients with a different genotype, one was 4/5, seven were 5/6 and one was 6/6. CONCLUSION: These results suggest that variants of the GGGA polymorphism from the estrogen receptor alpha gene may be associated with an increased risk of developing prostate cancer.
