A non-coding cancer mutation disrupting an HNF4α binding motif affects an enhancer regulating genes associated to the progression of liver cancer.

BACKGROUND: Somatic mutations in coding regions of the genome may result in non-functional proteins that can lead to cancer or other diseases, however cancer mutations in the non-coding regions have rarely been studied and the interpretation of their effects is difficult. Non-coding mutations might act by breaking or creating transcription factor binding motifs in promoters, enhancers or silencers resulting in altered expression of target gene(s). A high number of mutations have been reported in coding and non-coding regions in cells of liver cancer. Hepatocyte nuclear factor 4α is a transcription factor that regulates the expression of several genes in liver cells, while the motifs it binds are frequently mutated in promoters and enhancers in liver cancer. AIM: The aim of the study is to evaluate the genetic effects of a non-coding somatic mutation frequently observed in liver cancer. MATERIALS AND METHODS: We evaluated experimentally the effects of a somatic mutation frequently reported in liver cancer as a motif-breaker for the binding of hepatocyte nuclear factor 4α. The effects of the mutation on protein binding and enhancer activity were studied in HepG2 cells via electrophoresis mobility shift assay and dual luciferase reporter assays. We also studied genome-wide promoter-enhancer interactions performing targeted chromosome conformation capture in liver tissue to identify putative target genes whose expression could be altered by the mutation. RESULTS: We found that the mutation leads to reduced protein binding and a decrease in enhancer activity. The enhancer harboring the mutation interacts with the promoters of ANAPC13, MAP6D1 and MUC13, which have been implicated in liver cancer. CONCLUSIONS: The study highlights the importance of non-coding somatic mutations, vastly understudied, but likely to contribute to cancer development and progression.

Effects of the supplemental chromium form on performance and metabolic profile in laying hens exposed to heat stress.

This experiment was conducted to compare the effect of the supplemental chromium (Cr) form on performance, egg quality, and metabolic profile in laying hens exposed to heat stress (HS). Laying hens (n = 1800; 16-wk-old; Lohmann LSL-Lite) were kept in cages in temperature-controlled rooms at either 22 ± 2°C for 24 h/d (thermoneutral, TN) or 34 ± 2°C for 8 h/d, from 08:00 to 17:00 h, followed by 22°C for 16 h (HS) for 12 wks. Hens reared under both environmental conditions were fed 1 of 3 diets: a basal diet and the basal diet supplemented with either 1.600 mg of chromium-picolinate (CrPic, 12.43% Cr) or 0.788 mg of chromium-histidinate (CrHis, 25.22% Cr) per kg of diet, delivering 200 µg elemental Cr per kg diet. Data were analyzed by 2-way ANOVA. Exposure to HS caused decreases in feed intake (P < 0.0001), egg production (P < 0.0001), egg weight (P < 0.0001), eggshell weight (P < 0.0009), eggshell thickness (P < 0.0001), eggshell strength (P < 0.0001), and Haugh unit (P < 0.0001), deterioration in feed conversion ratio (P < 0.0001), increases in serum glucose and cholesterol concentrations (P < 0.0001 for both), decreases in serum and egg yolk Cr concentrations (P < 0.0001 for both), and decreases in serum Na (P < 0.002) and K (P < 0.01) concentrations. Both Cr sources were equally effective in alleviating performance variables under the HS condition. However, neither Cr sources alleviated deteriorations in egg quality parameters and serum electrolytes. Both Cr sources decreased serum glucose and cholesterol concentrations and increased serum and egg yolk Cr concentrations under the HS condition. In conclusion, HS adversely affected laying performance, egg quality, and metabolic profile. Both CrPic and CrHis partially alleviated the adverse effect of HS on these parameters. Inclusion of either Cr source could be a part of nutritional management strategies to overcome the adverse effects of HS performance and metabolic profile in laying hens.

Effects of the supplemental chromium form on performance and oxidative stress in broilers exposed to heat stress.

This experiment was conducted to investigate effects of the organic complex form of supplemental chromium (Cr) on performance, oxidative stress markers, and serum profile in broilers exposed to heat stress (HS). A total of 1,200 10-day-old boilers (Ross-308) was divided into one of the 6 treatments (2 environmental temperatures x 3 diets with different Cr forms). The birds were kept in temperature-controlled rooms at either 22 ± 2°C 24 h/d (thermoneutral, TN group) or 34 ± 2°C for 8 h/d, 08:00 to 17:00 h, followed by 22°C for 16 h (HS group) and fed either a basal diet (C) or the basal diet supplemented with Cr (200 µg/kg) through 1.600 mg of CrPic (12.43% Cr) and 0.788 mg of CrHis (25.22% Cr). Feed intake and body weight were recorded weekly. After cervical dislocation, liver samples were harvested to analyze Cr concentration and glucose transporter-2,4 (GLUT-2,4) expression. The breast meat also was sampled for the concentration of Cr and expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor kappa B (NF-κB). Data were analyzed by 2-way ANOVA. Heat stress caused depressions in feed intake (12.1%) and weight gain (21.1%) as well as elevations in feed conversion (11.2%) and abdominal fat (32.8%). It was also associated with depletion of Cr reserves and increases in serum concentrations of glucose, cholesterol, creatine, and enzymes. Exposure to HS was accompanied by suppression of the expressions of Nrf2 and GLUT-2 in muscle and GLUT-4 in the liver and amplification of the expression of NF-κB in muscle. Both Cr sources partially alleviated detrimental effects of HS on performance and metabolic profile. The efficacy of Cr as CrHis was more notable than Cr as CrPic, which could be attributed to higher bioavailability. In conclusion, CrHis can be added into the diet of broilers during hot seasons to overcome deteriorations in performance and wellbeing related to oxidative stress.

'True' null allele detection in microsatellite loci: a comparison of methods, assessment of difficulties and survey of possible improvements.

Null alleles are alleles that for various reasons fail to amplify in a PCR assay. The presence of null alleles in microsatellite data is known to bias the genetic parameter estimates. Thus, efficient detection of null alleles is crucial, but the methods available for indirect null allele detection return inconsistent results. Here, our aim was to compare different methods for null allele detection, to explain their respective performance and to provide improvements. We applied several approaches to identify the 'true' null alleles based on the predictions made by five different methods, used either individually or in combination. First, we introduced simulated 'true' null alleles into 240 population data sets and applied the methods to measure their success in detecting the simulated null alleles. The single best-performing method was ML-NullFreq_frequency. Furthermore, we applied different noise reduction approaches to improve the results. For instance, by combining the results of several methods, we obtained more reliable results than using a single one. Rule-based classification was applied to identify population properties linked to the false discovery rate. Rules obtained from the classifier described which population genetic estimates and loci characteristics were linked to the success of each method. We have shown that by simulating 'true' null alleles into a population data set, we may define a null allele frequency threshold, related to a desired true or false discovery rate. Moreover, using such simulated data sets, the expected null allele homozygote frequency may be estimated independently of the equilibrium state of the population.

Evaluation of hyperprolactinaemia with the use of the intervals for prolactin after macroforms separation.

Macroprolactin (MaPRL) - a complex of monomeric prolactin (PRL) with immunoglobulin G, may be a cause of laboratory diagnosed hyperprolactinaemia. To quantify MaPRL, a precipitation with polyethylene glycol may be performed. This method involves calculating of recovery ratio but the cut-off value is not precisely determined. Moreover, it is proposed that the assessment of macroprolactinaemia should include also the evaluation of real PRL concentration which means the level of the hormone after macroforms separation. The study included 245 patients with hyperprolactinaemia, in whom precipitation was performed. A recovery ratio ≤40% indicated macroprolactinaemia. The real PRL concentrations of the studied subjects were compared with reference ranges suggested by the assay manufacturer and with new intervals for PRL after macroforms separation. On the base of the recovery ratio after the precipitation, macroprolactinaemia was detected in 21 persons. In these patients true hyperprolactinaemia (elevation of real PRL concentration above manufacturer's reference ranges) was noted in 9 cases. Among 224 patients with a recovery >40%, real PRL concentration turned out to be within the manufacturer's reference range (pseudohyperprolactinaemia) in 36 persons. The new intervals for PRL after macroforms separation were about 20% lower than the manufacturer's reference ranges. After applying new ranges in patients with macroprolactinaemia, true hyperprolactinaemia was observed in 14 persons, while in the group without MaPRL dominance, pseudohyperprolactinaemia was noted in 5 patients. The use of the recovery ratio only to recognize macroprolactinaemia may lead in some subjects to the misclassification of the results. For that reason the assessment of the PRL concentration after macroforms separation that can help to distinguish true hyperprolactinaemia and pseudohyperprolactinaemia, seems to be reasonable. To evaluate the real PRL concentration, the reference intervals suggested by the manufacturer of immunoassay might be used. However, possibly better means to diagnose patients with hyperprolactinaemia accurately is using an appropriate range for the concentration of PRL after macroforms separation.

Inhibitory effect of prolactin on Toxoplasma proliferation in peripheral blood mononuclear cells from patients with hyperprolactinemia.

Despite many years of studies on the mechanisms of immunological defence responses induced in host organisms by Toxoplasma, no satisfactory immunoprophylaxis or chemotherapy have yet been established for humans. Thus, alternative methods to prevent toxoplasmosis and to enhance the efficacy of currently used antitoxoplasmic drugs are under evaluation. In this work, we strove to determine the influence of human prolactin (endogenous present in serum--sPRL and recombinant--rhPRL) on the course of Toxoplasma infection of peripheral blood mononuclear cells (PBMC) originating from female hyperprolactinemia patients. This study revealed that exogenous rhPRL as well as autologous sPRL from inactivated sera significantly restricted intracellular growth of Toxoplasma in PBMC cultures. Moreover, analysis of IL-10 production by PBMC infected with Toxoplasma and cultured in the presence of sPRL showed a positive correlation between sPRL concentration and the level of IL-10. The obtained results could indicate the possible protective action of PRL in a host organism infected with Toxoplasma and suggest that a significant increase in the serum PRL level, during pregnancy for instance, might significantly limit the risk of Toxoplasma spreading and could play an important role in natural protection against toxoplasmosis. The mechanism of inhibitory effect of PRL needs further detailed study.

Chromium histidinate protects against heat stress by modulating the expression of hepatic nuclear transcription factors in quail.

1. This experiment was conducted to evaluate the effects of supplemental chromium histidinate (CrHis) on performance and expressions of hepatic nuclear factors kappaB, an enhancer (NF-κB) and an inhibitor (IκBα) of activated B cells in heat-stressed Japanese quail (Coturnix coturnix japonica). 2. A total of 180, 10-d-old Japanese quail were allocated randomly into 6 groups in a 2 × 3 factorial arrangement. Birds were reared either at 22°C for 24 h/d (thermoneutral, TN) or 34°C for 8 h/d (heat stress, HS) for 32 d and fed on one of three diets supplemented with 0, 400 or 800 µg of CrHis per kg of diet. Each group consisted of 10 cages, each containing three quail. Data (performance variables and hepatic NF-κB and IκBα) were analysed using 2-way ANOVA. 3. Heat stress caused reductions in cumulative feed intake (FI) by 5·7%, weight gain (WG) by 13·0%, final body weight (FBW) by 10·3%, carcase weight by 12·6% and carcase efficiency by 2·3% and an increase in feed conversion ratio (FCR, feed consumed, g:weight gained, g) by 8·4%. As supplemental CrHis level increased up to 800 µg/kg, there were linear increases in cumulative FI (from 602 to 609 g), WG (from 134 to 138 g), FBW (from 167 to 171 g), cold carcase weight (from 110 to 114 g) and cold carcase efficiency (from 65·5 to 66·4%) and a decrease in FE (from 4·51 to 4·42). The environmental temperature by CrHis level interaction effect on performance parameters was insignificant. Hepatic NF-κB p65 concentration was higher and hepatic IκBα concentration was lower in quail exposed to HS than in quail kept at TN temperature. Increasing supplemental CrHis level linearly inhibited hepatic NF-κB p65 expression from 134·4 to 105·3% and linearly enhanced hepatic IκBα expression from 73·4 to 99·6%. The decrease in hepatic NF-κB expression and the increase in hepatic IκB expression were more notable in the TN environment than in the HS environment. 4. In conclusion, heat stress depressed performance variables and augmented lipid peroxidation and supplemental CrHis alleviated oxidative stress through modulating expressions of stress-related hepatic nuclear transcription factors (NF-κB and IκBα).

Osteopontin and endostatin concentrations in peripheral blood of patients with adrenal tumors undergoing unilateral adrenalectomy.

Peripheral blood osteopontin (OPN) and endostatin (END) levels were studied in 35 patients with adrenal cortex tumors and 10 patients with pheochromocytoma before unilateral adrenalectomy, as well as in 10 healthy subjects (controls). Thirty days after surgery, OPN and END were evaluated again in 16 patients with adrenal cortex tumors and 4 female patients with pheochromocytoma. Before surgery, OPN blood concentrations increased in the group of patients with adrenal cortex carcinomas as compared to controls (p < 0.001) and the group with Conn syndrome (p < 0.05); they did not change after surgery. Before adrenalectomy, OPN blood levels in pheochromocytoma patients were also lower than in Conn syndrome subjects (p < 0.05). After adrenalectomy, the normal concentrations of END decreased only in the group of patients with hormonally inactive cortical adenomas (p < 0.05). We were unable to demonstrate any relationships between removed tumor volumes and OPN or END blood levels.

Differential gene expression in the olfactory bulb following exposure to the olfactory toxicant 2,6-dichlorophenyl methylsulphone and its 2,5-dichlorinated isomer in mice.

2,6-Dichlorophenyl methylsulphone and a number of structurally related chemicals are CYP-activated toxicants in the olfactory mucosa in mice and rats. This toxicity involves both the olfactory neuroepithelium and its subepithelial nerves. In addition, 2,6-dichlorophenyl methylsulphone induces glial acidic fibrillary protein expression (Gfap, a biomarker for gliosis) in the olfactory bulb, as well as long-lasting learning deficits and changes in spontaneous behavior in mice and rats. So far the 2,5-dichlorinated isomer has not been reported to cause toxicity in the olfactory system, although it gives rise to transient changes in spontaneous behavior. In the present study we used 15k cDNA gene arrays and real-time RT-PCR to determine 2,6-dichlorophenyl methylsulphone-induced effects on gene expression in the olfactory bulb in mice. Seven days following a single ip dose of 2,6-dichlorophenyl methylsulphone, 56 genes were found to be differentially expressed in the olfactory bulb. Forty-one of these genes clustered into specific processes regulating, for instance, cell differentiation, cell migration and apoptosis. The genes selected for real-time RT-PCR were chosen to cover the range of B-values in the cDNA array analysis. Altered expression of Gfap, mt-Rnr2, Ncor1 and Olfml3 was confirmed. The expression of these genes was measured also in mice dosed with 2,5-dichlorophenyl methylsulphone, and mt-Rnr2 and Olfml3 were found to be altered also by this isomer. Combined with previous data, the results support the possibility that the persistent neurotoxicity induced by 2,6-dichlorophenyl methylsulphone in mice represents both an indirect and a direct effect on the brain. The 2,5-dichlorinated isomer, negative with regard to CYP-catalyzed toxicity in the olfactory mucosa, may prove useful to resolve this issue.

Effects of hormone replacement therapy type and route of administration on plasma matrix metalloproteinases and their tissue inhibitors in postmenopausal women.

BACKGROUND: Matrix metalloproteinases (MMPs) are implicated in numerous disease states including cardiovascular disease and cancer. Because recent studies have shown a detrimental effect of hormone replacement therapy on cardiovascular disease and breast cancer, we investigated whether there are any differences in the concentrations of MMPs and their tissue inhibitors (TIMPs) in women receiving various forms of postmenopausal therapy. MATERIAL AND METHODS: A total of 195 healthy postmenopausal women were assessed: 46 were taking tibolone, 47 were taking transdermal estradiol, 46 were taking conjugated equine estrogens (CEE), and 56 were not taking any menopausal therapy (CTR). Plasma levels of MMP-2 and -9 and TIMP-1 and TIMP-2 were measured by ELISA methods. RESULTS: MMP-9 levels were significantly higher in the CEE group in comparison with healthy women not receiving menopausal therapy (P < 0.05). In contrast, MMP-9 levels in the tibolone group were significantly lower than in any other group (P < 0.01, compared with transdermal estradiol and CTR, and P < 0.001, compared with CEE). MMP-9 to TIMP-1 ratio was also significantly higher in the CEE, compared with CTR (P < 0.05), and lower in the tibolone group (P < 0.01, compared with all groups). MMP-2 levels were higher in the CEE group, compared with healthy women not receiving any menopausal therapy, and women taking tibolone (P < 0.05). CONCLUSIONS: Our study demonstrates differential effects of various forms of postmenopausal therapy on serum levels of MMP-9 and MMP-2. It remains to be established whether these differences might be associated with differences in risks of cardiovascular disease and cancer in these women.

Increased circulating levels of matrix metalloproteinase-2 and -9 in women with the polycystic ovary syndrome.

INTRODUCTION: Matrix metalloproteinases (MMPs) have been implicated in various pathological processes including inflammatory response, cardiovascular disease, and recently also in ovarian dysfunction. Polycystic ovary syndrome (PCOS) is the most common endocrinopathy in women of reproductive age and is characterized by chronic anovulation, insulin resistance, and increased prevalence of cardiovascular risk factors. Circulating levels of MMPs and their tissue inhibitors (TIMPs) so far have not been assessed in the PCOS. MATERIALS AND METHODS: Serum levels of MMP-2, MMP-9, TIMP-1, and TIMP-2 were measured in 23 women with PCOS [age (mean +/- sd), 30.5 +/- 6.7 yr; body mass index, 35.8 +/- 7.5 kg/m2] and 22 healthy, regularly menstruating women (age, 29.4 +/- 5.6; body mass index, 31.7 +/- 9.2 kg/m2). RESULTS: Women with PCOS had significantly higher concentrations of MMP-2 (999.8 +/- 155 vs. 521.8 +/- 242 ng/ml; P < 0.001), MMP-9 (592.4 +/- 279 vs. 345 +/- 309; P = 0.007), and TIMP-1 levels (823.8 +/- 145 vs. 692 +/- 210 ng/ml; P = 0.02) than control healthy women. There was no difference in TIMP-2 levels (47.3 +/- 30 vs. 44.4 +/- 39.7 ng/ml; P = 0.21) between women with PCOS and controls. CONCLUSIONS: Obese women with PCOS have elevated serum concentrations of MMP-2 and -9. It might be hypothesized that elevated MMP concentrations may be related to increased cardiovascular risk in PCOS and/or menstrual irregularities associated with this syndrome.

Effect of the growth hormone-releasing hormone [GHRH(1-44)NH2] on IL-6 and IL-8 secretion from human peripheral blood mononuclear cells in vitro.

OBJECTIVE: Bidirectional communication between the neuroendocrine and immune systems is now a subject of an intensive investigation. Growth hormone-releasing hormone (GHRH) is synthesized by the hypothalamus, but is present also in the immune cells. Some recent data indicate also an immunomodulatory role of the neuropeptide. The aim of the study was to examine the influence of GHRH(1-44)NH2 on interleukin-6 and interleukin-8 secretion from human peripheral blood mononuclear cells cultured in vitro. METHODS: Peripheral blood mononuclear cells (PBMC) were isolated by centrifugation using Böyum technique and cultured in a humidified atmosphere of 5 % CO2 and 95 % O2 at 37 degrees C for 24 hours in the presence of lipopolysaccharide (LPS) at the concentration of 2 microg/ml and GHRH(1-44)NH2 (the final neuropeptide concentrations to be tested were 10(-12) to 10(-6) M). ELISA methods were used to measure IL-6 and IL-8 concentrations in the supernatants of cultured cells RESULTS: GHRH(1-44)NH2 influenced IL-6 secretion from cultured cells, but significant inhibition of IL-6 release was observed at 10-6 M (p < 0.001). The negative correlation between the GHRH concentration studied and the IL-6 level in the supernatants was found (r = -0.759; p < 0.001). GHRH had no influence on the secretion of IL-8 from activated PBMC. CONCLUSIONS: Our results demonstrate that GHRH in vitro modulates IL-6 secretion from the human peripheral blood mononuclear cells, without any significant effect on IL-8 secretion.

Effect of thyroliberin on the course of experimental candidosis in mice.

Thyroliberin (TRH) is one of the hormones, which affect immunologic processes. This hormone was studied in experimental subacute candidosis in mice. BALB/c males were given intraperitoneally single dose of Candida albicans cells (1 x 10(7) to 1 x 10(9) cfu of strain no. 244-33 ATCC). The animals from the experimental groups were injected subcutaneously, after 24 h from inoculation, dose of 10 microg TRH in 0.2 ml 0.9% NaCl, seven times at 24 h intervals. The control animals were given respectively 0.2 ml of physiologic NaCl solution. We have found that the examined hormone significantly decreases mortality in these animals (LD50 C. albicans for mice treated with TRH was three times higher than that in the control groups), prolongs mean survival time for mice and decreases the intensity of fungal invasion of the animal organs.

Soluble intracellular adhesion molecules (sICAM-1, sVCAM-1) in peripheral blood of patients with thyroid cancer.

The growth of a neoplasm and its ability to form metastases is a multistep process dependent on angiogenesis and immunological reactions of the organism. In this process adhesive factors are also involved. The aim of this work was estimation of the concentration of soluble intercellular adhesion molecules (sICAM-1) and vascular cellular adhesion molecules (sVCAM-1) in the serum of peripheral blood of patients with thyroid cancer before operation. The study comprised 48 patients ( 38 women and 10 men) aged from 18 to 87 years, in whom thin needle aspiration biopsy revealed cancer of the thyroid. Postoperative histopathological examination showed papillary cancer in 35 patients, oxyphilic cancer in 5 patients, anaplastic cancer in 4 and medullary cancer in 4 patients. In those patients, using the immunoenzymatic method ELISA, the concentration of sICAM-1 and sVCAM-1 in the serum of peripheral blood was determined. The control group comprised 26 healthy persons. We found statistically significant increase of sICAM-1 concentration in serum in all forms of cancer, in comparison with the control group. Mean concentrations of sICAM-1 were as follows: in papillary cancer patients 455.23+/-28.66 vs. 299.62+/-11.54 ng/ml, p<0.05; in oxyphilic cancer 455.60+/-95.21 vs. 299.62+/-11.54 ng/ml, p<0.05; in anaplastic cancer 570.00+/-170.89 vs. 299.62+/-11.54 ng/ml, p<0.05; and in medullary cancer 512.00+/-11.46 vs. 299.62+/-11.54 ng/ml, p<0.05. The mean concentration of sVCAM-1 in serum was statistically significantly higher than in the control group only in case of anaplastic cancer (1033.75+/-86.30 vs. 644.58+/-27.30 ng/ml; p<0.05). We evaluated the correlation coefficient between the concentration of sICAM-1 and sVCAM-1 in the serum of patients with thyroid cancer. Positive correlation was observed between the concentration of sICAM-1 and sVCAM-1. The obtained results confirm essential role of the investigated adhesive factors in the process of thyroid cancer growth.

Effect of growth hormone-releasing hormone (GHRH) and GHRH antagonist (MZ-4-71) on interferon-gamma secretion from human peripheral blood mononuclear cells in vitro.

Numerous reports indicate close interactions between the neuroendocrine and the immune systems. Hypothalamic neuropeptide, growth hormone-releasing hormone (GHRH) stimulates growth hormone (GH) secretion from the anterior pituitary gland, but recently some immunomodulatory properties of this peptide have also been demonstrated. In the present studies we evaluated the effect of human synthetic GHRH(1-44)NH(2) and GHRH antagonist (MZ-4-71) on interferon (IFN)-gamma secretion from human peripheral blood mononuclear cells (PBMC). GHRH(1-44)NH(2) at 10(-10), 10(-8) and 10(-6) M concentrations significantly (p < 0.05) increased the IFN-gamma level in supernatants of cultured cells, as compared with the controls. GHRH antagonist (MZ-4-71) at 10(-10), 10(-8) and 10(-6) M concentrations diminished the IFN-gamma level in supernatants in a dose-dependent manner, but statistically significant differences were observed only at 10(-8) M and 10(-6) M (p < 0.05 vs controls). Our results demonstrate that GHRH and GHRH antagonist MZ-4-71 can modulate IFN-gamma secretion in vitro by human peripheral blood mononuclear cells.

GH-RH antagonist (MZ-4-71) inhibits VEGF secretion and proliferation of murine endothelial cells.

Angiogenesis plays a key role in solid tumor formation, invasiveness and metastasis. Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen that is necessary in the process of neovascularisation. Antagonists of growth hormone-releasing hormone (GH-RH) have been shown to suppress both in vivo and in vitro growth and metastasis of many human cancer cell lines. The mechanisms that mediate the antitumorigenic actions of these antagonists involve direct and indirect pathways, but are not completely elucidated. We have examined the effect of GH-RH antagonist MZ-4-71 on proliferation activity and VEGF release from cultured murine endothelial cells HECa10 in vitro. MZ-4-71 at 10(-8) to 10(-6) M concentrations inhibited the proliferative activity of cultured cells and suppressed the release of VEGF into supernatants of 72 h endothelial cell cultures. To our knowledge this is the first study reporting antiangiogenic properties of GH-RH antagonists.

Angiogenesis of endocrine gland tumours--new molecular targets in diagnostics and therapy.

Angiogenesis is one of the key stages in the development of neoplastic tumours, in which a small group of mutated cells transforms into a large malignant tumour metastasising to the neighbouring tissues and organs. The studies on the significance of neoangiogenesis in the progression of endocrine gland neoplasms have recently become one of the most rapidly evolving branches of molecular endocrinology. The induction of angiogenesis has been demonstrated to result from the imbalance between positive and negative factors which control this process. Our paper presents the results of current studies on the role of factors such as molecular markers of angiogenesis (e.g. vascular endothelial growth factor and basic fibroblast growth factor), metalloproteinases (which regulate the decomposition of the extracellular matrix) and their inhibitors, and adhesive molecules (e.g. soluble vascular cellular adhesion molecule-1 and soluble intracellular adhesion molecule-1) in the pathogenesis and diagnostics of endocrine gland tumours in humans. Also, we discuss new therapeutic strategies for inhibiting the growth of neoplasms by blocking the formation of blood vessels using angiogenesis antagonists, which inhibit various stages of angiogenesis. More and more data are being accumulated suggesting that these preparations could, in the near future, be used in the pharmacotherapy of some endocrine gland neoplasms.

[New knowledge derived from measurement of gene expression with the DNA microarray method]. / Ny kunnskap fra måling av genuttrykk gjennom DNA-mikromatrise.

BACKGROUND: The cDNA microarray method offers the first possibility of obtaining a global understanding of biological processes in living organisms, by simultaneous read-outs of tens of thousands of mRNAs. Initial experiments suggest that genes with similar function have similar expression patterns. MATERIAL AND METHODS: Understanding this level of biological complexity will, however, require completely new approaches to data analysis. Computer science methods, such as data mining and knowledge discovery, can synthesize interpretable if-then rules that model the relation between gene expressions and functions and use the rules to classify unknown genes. The huge body of existing biological and medical knowledge makes it necessary to develop methods for extracting knowledge from such repositories. RESULTS: Models of relations between gene expressions and gene functions in a data set from a publicly available source are synthesized semiautomatically and applied to classify unknown genes. Encouraging results have been achieved. The method is applied in the analysis of data from our microarray system which has recently become operational. INTERPRETATION: The principles are of general importance and will be used to evaluate a wide range of complex data sets like decision support in clinical medicine, for situations in which physicians need to handle a large volume of data for each patient.

A literature network of human genes for high-throughput analysis of gene expression.

We have carried out automated extraction of explicit and implicit biomedical knowledge from publicly available gene and text databases to create a gene-to-gene co-citation network for 13,712 named human genes by automated analysis of titles and abstracts in over 10 million MEDLINE records. The associations between genes have been annotated by linking genes to terms from the medical subject heading (MeSH) index and terms from the gene ontology (GO) database. The extracted database and accompanying web tools for gene-expression analysis have collectively been named 'PubGene'. We validated the extracted networks by three large-scale experiments showing that co-occurrence reflects biologically meaningful relationships, thus providing an approach to extract and structure known biology. We validated the applicability of the tools by analyzing two publicly available microarray data sets.