p53 is a complex molecule involved in apoptosis, cell cycle arrest, and DNA repair. Since apoptosis may play an important role in deletion of neoplastic cells, an understanding of the mechanism of p53-induced apoptosis may be critical for possible future therapeutic interventions. Recent evidence suggests that p53-induced apoptosis may involve members of the nucleotide excision repair (NER) family, linking these two cellular events.
View Article and Find Full Text PDFObjective: To determine whether polymorphism in the manganese superoxide dismutase (MnSOD) gene is associated with susceptibility or disease outcome in rheumatoid arthritis (RA).
Methods: We used a case-control approach with 153 RA patients and 218 control subjects to examine for any associations between MnSOD genotypes and susceptibility to RA. We also investigated the influence of genotypes on radiologic outcome, as measured using the Larsen score for radiographs of the hands and feet, and on functional outcome, as assessed by the Health Assessment Questionnaire.
Tumour necrosis factor alpha (TNF-alpha) appears important in ultraviolet-induced immunosuppression, suggesting that it is a susceptibility candidate for cutaneous basal cell carcinoma (BCC). We now describe data on the association between TNF microsatellite polymorphisms, first on susceptibility in 202 controls and 133 cases each having two to 30 BCCs, and secondly, within the cases, on BCC numbers. The data show that the proportions of individuals with TNF a1- and a7-containing genotypes were significantly different (P = 0.
View Article and Find Full Text PDFThe glutathione S-transferases (GST) are a supergene family of dimeric, enzymes that catalyse the conjugation of glutathione (GSH) to a variety of electrophiles including arene oxides, unsaturated carbonyls, organic halides and other substrates. Their importance is suggested by the finding that GST enzymes are expressed in probably all life forms. In humans, polymorphism in GST genes has been associated with susceptibility to various diseases though some recent data indicate that these genotypes modify disease phenotype.
View Article and Find Full Text PDFAllelic variants of the apolipoprotein E (APOE) gene influence the course of several neurological diseases. In multiple sclerosis the concentration of APOE in cerebrospinal fluid and its intrathecal synthesis is reduced. Specific isoforms of APOE may also be important and it has been suggested that possession of the epsilon4 allele may be associated with a more aggressive disease process.
View Article and Find Full Text PDFCalcitriol [1,25(OH)2D3], the hormonal derivative of vitamin D3, is an antiproliferative and prodifferentiation factor for several cell types, including cultured melanocytes and malignant melanoma (MM) cells. Several polymorphisms of the vitamin D receptor (VDR) gene have been described including a FokI RFLP in exon 2, BsmI, and ApaI polymorphisms in intron 8 and an adjacent TaqI RFLP in exon 9. Alterations in vitamin D/1,25(OH)2D3 levels and polymorphisms of the VDR have been shown to be associated with several systemic malignancies.
View Article and Find Full Text PDFBackground: Oxidative stress has been implicated in inflammatory demyelination. The glutathione S-transferase (GST) supergene family encodes isoenzymes that appear to be critical in protection against oxidative stress. Certain GST loci are polymorphic, demonstrating alleles that are null (GSTM1/GSTT1), encode low activity variants (GSTP1), or are associated with variable inducibility (GSTM3).
View Article and Find Full Text PDFMammary gland form and function are regulated by interactions between epithelium and extracellular matrix. Major glycoprotein components of extracellular matrix have been identified that give survival, proliferation and differentiation signals to mammary epithelial cells. We provide evidence that proteolytic fragments of the extracellular matrix glycoprotein, fibronectin, suppress growth and can promote apoptosis of mouse mammary epithelial cells.
View Article and Find Full Text PDFWhile ultraviolet (UV) exposure is thought to be a major risk factor for basal cell carcinoma (BCC) and squamous cell carcinoma, more recent research has focused on genetic factors predisposing to these cancers. UV constitutes an oxidative stress with generation of free radicals, leading to lipid and DNA damage and gene mutation. It could therefore be hypothesized that individual ability to deal with these products may be important in cutaneous carcinogenesis.
View Article and Find Full Text PDFJ Opt Soc Am A Opt Image Sci Vis
January 2000
Near-field designs of Fresnel and Gabor zone plates are computationally analyzed by using versions that allow the foci to be brought closer to the plate than in the usual far-field applications. It is found that the Fresnel plate has a dominant primary conjugate pair of foci well inside the far-field region and a more intense primary focus and smaller off-focal-plane sidelobes than the near-field Gabor systems, thus yielding a superior imaging performance.
View Article and Find Full Text PDFThe expression of cyclin D1 protein in tumour sections from 81 patients with epithelial ovarian cancer was analysed using immunohistochemistry. The tumours that overexpressed cyclin D1 in more than 10% of neoplastic cells were considered positive. Thus overexpression of cyclin D1 was observed in 72/81 (89%) of the cases examined.
View Article and Find Full Text PDFInterleukin-10 (IL10) is an anti-inflammatory cytokine which may modulate disease expression in multiple sclerosis (MS). Three dimorphic polymorphisms within the IL10 promoter region at positions - 1082, -819 and -519 have previously been identified. The - 1082*A allele has been associated with low and the - 1082*G allele with high in vitro IL10 production.
View Article and Find Full Text PDFType 1 Cu centers in cupredoxins, nitrite reductases, and multi-copper oxidases utilize the same trigonal core ligation to His-Cys-His, with a weak axial ligand generally provided by a Met sulfur. In azurin, an additional axial ligand, a carbonyl oxygen from a Gly, is present. The importance of these axial ligands and in particular the Met has been debated extensively in terms of their role in fine-tuning the redox potential, spectroscopic properties, and rack-induced or entatic state properties of the copper sites.
View Article and Find Full Text PDFGST, CYP, and CCND1 genotypes have been associated with outcome in several cancers. Accordingly, we have examined, in patients with one squamous cell carcinoma (SCC) of the head and neck, associations between GSTM1, GSTT1, GSTM3, GSTP1, CYP2D6, CYP1A1, CYP2E1, and CCND1 genotypes and the outcome parameters, tumor extension, histological grade, and presence of nodes. We used logistic regression to study, first, each gene individually and, second, in a step-wise model that included all of the genes.
View Article and Find Full Text PDFIARC Sci Publ
October 1999
The glutathione S-transferase supergene family is an important part of cellular enzymic defence against endogenous and exogenous chemicals, many of which have a carcinogenic potential. However, while a wide variety of chemicals can act as substrates for different members of the supergene family, the precise function of these enzymes remains unclear. The supergene family comprises several gene families that include polymorphic loci, prompting the hypothesis that allelic variants associated with less effective detoxification of potential carcinogens can confer an increased susceptibility to cancer.
View Article and Find Full Text PDFWe previously identified associations between polymorphism in the cytochrome P450 CYP2D6 gene and outcome in several cancers. We have now examined the hypothesis that homozygosity for the mutant alleles, CYP2D6*4 and CYP2D6*3, is associated with susceptibility and outcome in malignant melanoma. Outcome was assessed by Breslow thickness.
View Article and Find Full Text PDFSkin cancer is a well-recognized risk of prolonged immunosuppression, for example, following renal transplantation. These tumours contrast with idiopathic lesions in that squamous cell, rather than basal cell carcinomas usually predominate. We report a Caucasian female who developed multiple basal cell carcinomas following protracted cytotoxic therapy for acute myeloid leukaemia and subsequently chronic lymphocytic leukaemia.
View Article and Find Full Text PDFFixL is a heme-based O(2) sensor protein involved in a two-component system of a symbiotic bacterium. In the present study, the iron coordination structure in the heme domain of Rhizobium meliloti FixLT (RmFixLT, a soluble truncated FixL) was examined using Fe K-edge extended x-ray absorption fine structure (EXAFS) and resonance Raman spectroscopic techniques. In the EXAFS analyses, the interatomic distances and angles of the Fe-ligand bond and the iron displacement from the heme plane were obtained for RmFixLT in the Fe(2+), Fe(2+)O(2), Fe(2+)CO, Fe(3+), Fe(3+)F(-), and Fe(3+)CN(-) states.
View Article and Find Full Text PDFIn the absence of pregnancy, the adult mammary gland is subjected to cyclic fluctuations of hormonal stimulation that constitute the estrous and menstrual cycles. The mammary epithelium responds to these systemic hormonal changes by regional proliferation, differentiation and cell death by apoptosis. The fact that the mammary epithelial response involves only a minor subset of the epithelial cells implies a delicate local control of epithelial cell fate resulting in either cell death or survival.
View Article and Find Full Text PDFBackground: While cigarette smoking and alcohol consumption are the major risk factors for the development of head and neck carcinomas, it is assumed that genetic factors contribute to risk. The aim of this study was to characterize the influence of the carcinogen metabolizing glutathione-S-transferases on susceptibility to head and neck carcinomas.
Patients And Methods: Polymorphisms at GSTM1, M3, T1 and P1 gene loci were determined in 398 head and neck cancer patients and 216 controls using polymerase chain reaction and restriction enzyme digestion.
Glutathione S-transferase GSTM1 B and GSTT1 null, and cytochrome P450 CYP2D6 EM have been associated with cutaneous basal cell carcinoma (BCC) numbers, although their quantitative effects show that predisposition to many BCC is determined by an unknown number of further loci. We speculate that other loci that determine response to oxidative stress, such as NAD(H):quinone oxidoreductase (NQO1) are candidates. Accordingly, we assessed the association between NQO1 null and BCC numbers primarily to rank NQO1 null in a model that included genotypes already associated with BCC numbers.
View Article and Find Full Text PDFObjective: To determine whether glutathione S-transferase GSTM1, GSTM3, GSTT1, and GSTP1 genotypes influence susceptibility or outcome in rheumatoid arthritis (RA).
Methods: 277 RA patients were compared with 577 controls to examine any associations between GST genotypes and susceptibility to RA. The effect of genotypes on outcome (Larsen and functional scores) and time integrated acute phase responses (erythrocyte sedimentation rate and C reactive protein) was assessed in 122 patients with disease duration of 5-10 years.
Allelic variants in the melanocyte stimulating hormone receptor (MC1R) gene are susceptibility/outcome candidates for cutaneous basal cell carcinoma (BCC). We identified the val92met (V92M) and asp294his (A294H) alleles in 311 cases and 190 controls. The cases included four homo- and 53 heterozygotes for V92M and 12 heterozygotes for A294H and two compound heterozygotes (V92M/A294H).
View Article and Find Full Text PDFObjectives: To investigate whether the therapeutic response of rheumatoid arthritis (RA) patients to D-penicillamine is associated with polymorphisms in genes of the glutathione S-transferase (GST) supergene family.
Methods: Disease activity in 81 patients with RA treated with D-penicillamine monotherapy was assessed using the Stoke Index, a validated index of disease activity, prior to treatment and at 6 months. GST typing was performed using a polymerase chain reaction-based approach and a logistic regression model was used to investigate any possible association between the therapeutic response to D-penicillamine and the GST genotype.