Proteases and their inhibitors as prognostic factors for high-grade serous ovarian cancer

Ovarian carcinoma is one of the most lethal malignancies, but only very few prognostic biomarkers are known. The degradome, comprising proteases, protease non-proteolytic homologues and inhibitors, have been involved in the prognosis of many cancer types, including ovarian carcinoma. The prognostic significance of the whole degradome family has not been specifically studied in high-grade serous ovarian cancer. A targeted DNA microarray known as the CLIP-CHIP microarray was used to identify potential prognostic factors in ten high-grade serous ovarian cancer women who had early recurrence (<1.6 years) or late/no recurrence after first line surgery and chemotherapy. In women with early recurrence, we identified seven upregulated genes (TMPRSS4, MASP1/3, SPC18, PSMB1, IGFBP2, CFI – encoding Complement Factor I – and MMP9) and one down-regulated gene (ADAM-10). Using immunohistochemistry, we evaluated the prognostic effect of these 8 candidate genes in an independent cohort of 112 high-grade serous ovarian cancer women. Outcomes were progression, defined according to CA-125 criteria, and death. Multivariate Cox proportional hazard regression models were done to estimate the associations between each protein and each outcome. High ADAM-10 expression (intensity of 2–3) was associated with a lower risk of progression (adjusted hazard ratio (HR): 0.51; 95% confidence interval (CI): 0.29-0.87). High complement factor I expression (intensity 2–3) was associated with a higher risk of progression (adjusted HR: 2.30, 95% CI: 1.17–4.53) and death (adjusted HR: 3.42; 95% CI: 1.72–6.79). Overall, we identified the prognostic value of two proteases, ADAM-10 and complement factor I, for high-grade serous ovarian cancer which could have clinical significance.     

Ultrastructural changes in hepatocytes of precision-cut rat liver slices after incubation for 24 and 48 hours

Hepatocytes of precision-cut rat liver slices were studied by means of transmission electron microscopy after long-term incubation (24–48 h) in comparison with freshly prepared slices, indicating reversible and irreversible intracellular alterations of the cells. After 24 h incubation the morphological image in transversal sections of slices is characterised by a central zone of damaged and necrotic cells flanked by two to several superficial layers of viable cells. This is typical of a diffusion gradient of oxygen tension and nutrient content from the surface to the centre of the slices. In adapted cells on the surface of the slices we observed an organelle-free layer of fine granular material in the apical cytoplasm followed by parallel oriented stacks of rough endoplasmic reticulum near by. Mitochondria of essentially normal appearance in adapted cells did not contain flocculent densities, which were observed in damaged cells only. The cytoplasm of parenchymal cells consisted of defined areas of clear cytoplasmic material containing numerous branching tubular profiles of smooth endoplasmic reticulum, presumably in the regions with depleted glycogen aggregates. Subcellular signs of necrosis are destroyed mitochondria, dilated endoplasmic reticulum free of ribosomes and clumping of chromatin in the nucleus of hepatocytes. No appreciable differences of the cell organelles were observed between 24 and 48 h of incubation, but the incidence and intensity of signs of necrosis increased with the duration of incubation and the thickness of the slices. The process of these changes may reflect the phenomenon of cellular adaptation and of hypoxic cellular injury in the periphery and the centre of the slices, respectively.     

ATPASE-ASSOCIATED ANTIGEN (M2): MARKER ANTIGEN FOR SEROLOGICAL DIAGNOSIS OF PRIMARY BILIARY CIRRHOSIS

Serum samples from 94 patients with primary biliary cirrhosis (PBC) and 17 patients with chronic cholestatic hepatitis (CCH) were tested in the fluorometric immunoassay (FIAX) against the non-organ-specific ATPase-associated antigen (M2) and against submitochondrial particles (SMP) and sonicated mitochondria from beef heart and rat liver, to evaluate the specificity and sensitivity of the M2 antigen for the diagnosis of PBC. As controls serum samples from 42 patients with other antimitochondrial antibody (AMA) specificity (against M1, M3, M5, and M6) as well as samples from 417 patients with various other hepatic and non-hepatic disorders were used. Serum samples from 91 of the 94 PBC patients (97%) and all 17 with CCH reacted with the M2 antigen. However, when SMP from rat liver and beef heart were tested in parallel in the FIAX, AMA could be detected in all PBC serum samples. None of the 42 patients with different types of AMA had reactions with the M2 antigen but all had reactions with SMP from rat-liver or beef-heart mitochondria or both. Among the other 417 patients with hepatic and non-hepatic disorders only 4 (1%), all with collagen diseases, had anti-M2 antibodies.     

Uptake and presentation of hepatitis C virus-like particles by human dendritic cells

Hepatitis C virus (HCV) is a major cause of chronic hepatitis worldwide. Interaction of dendritic cells (DCs) with viral particles may play an important role in the immunopathogenesis of HCV infection. Since the synthesis or purification of infectious virions is limited, we used HCV-like particles (HCV-LPs) to study the interaction of HCV with human DCs. Immature DCs exhibited an envelope-specific and saturable binding of HCV-LPs, indicating receptor-mediated DC-HCV-LP interaction. Confocal microscopy revealed that HCV-LPs were rapidly taken up by DCs in a temperature-dependent manner. Competition experiments demonstrated that C-type lectins such as mannose receptor or DC-SIGN (DC-specific intercellular adhesion molecule 3-grabbing nonintegrin) were not sufficient for mediating HCV-LP binding. HCV-LP uptake was followed by DC activation. DCs pulsed with HCV-LPs stimulated HCV core-specific CD4(+) T cells, indicating that uptake of HCV-LPs by DCs leads to antigen processing and presentation on major histocompatibility complex (MHC) class II molecules. Finally, HCV-LP-derived antigens were efficiently cross-presented to HCV core-specific CD8(+) T cells. These findings demonstrate that HCV-LPs represent a novel model system to study HCV-DC interaction allowing definition of the molecular mechanisms of HCV uptake, DC activation, and antigen presentation to T cells. Furthermore, HCV-LP-mediated DC activation and efficient antigen presentation may explain the marked immunogenicity of HCV-LPs in vivo.     

Induction of antibodies to viscotoxins A1, A2, A3, and B in tumour patients during therapy with an aqueous mistletoe extract

Mistletoe extracts exert immunomodulatory properties on immunocompetent cells of the innate as well as the specific immune system. These effects have been mainly ascribed to mistletoe lectin 1 (ML-1) present in most of the extracts. However, it became evident that also other components of these extracts may induce immunological reactions, and especially viscotoxins (VT) may be of relevance. Aim of the study was, therefore, to evaluate whether VT like ML-1 could activate B-cells and lead to the production of VT-specific antibodies. Sera from 26 patients with different tumours who were treated with the mistletoe extract ABNOBAviscum Mali (AM) 4 for at least 18 weeks were analysed before therapy and after 3, 6, 9, 12, and 18 weeks. Sera were tested by ELISA against the four viscotoxins A1, A2, A3, B, as well as against ML-1. Within the observation period twenty-four (92%) of the 26 patients developed antibodies to at least one of the four VT and 25 (96%) to ML-1. In most instances, anti-VT antibodies appeared after 6-9 weeks of treatment. The antibodies were predominantly of the IgG type belonging preferentially to the IgG1 and IgG3 subclass. IgE antibodies were found only to VT-B and to ML-1. There was no relation between the development of antibodies to VT and ML-1, and also cross-reactivity could be excluded with high probability. These data indicate that not only ML-1 but also VT induce immunological responses in patients treated with mistletoe extracts. Whether there is any relationship to the postulated anti-tumour effect of mistletoe extracts has, however, still to be evaluated.     

5,10-Methylenetetrahydrofolate reductase genotype determines the plasma homocysteine-lowering effect of supplementation with 5-methyltetrahydrofolate or folic acid in healthy young women

BACKGROUND: Elevated plasma total homocysteine (tHcy) is a risk factor for vascular disease and neural tube defects. The polymorphism in the gene encoding 5,10-methylenetetrahydrofolate reductase (FADH(2)) (MTHFR) influences the tHcy concentration and the response to tHcy-lowering therapy. Supplementation with folic acid (FA) decreases plasma tHcy, but limited data are available on the effect of 5-methyltetrahydrofolate (MTHF). OBJECTIVE: We evaluated the tHcy-lowering potential of low-dose FA and of MTHF with respect to the MTHFR genotype. DESIGN: In this randomized, placebo-controlled, double-blind study, 160 women received 400 microg FA, the equimolar amount of MTHF (480 microg, racemic mixture), or a placebo daily during an 8-wk treatment period. Blood samples were collected at baseline and at 4 and 8 wk. RESULTS: Changes in plasma tHcy concentration depended on the supplemented folate derivative and the MTHFR genotype. Supplementation with FA significantly decreased tHcy concentrations by > or = 13% in women of all 3 genotypes after both 4 and 8 wk. The greatest decrease was 20% (P < 0.05) in the women with the TT genotype after 4 wk. MTHF supplementation also decreased tHcy, but only the women with the CT genotype had a significant decrease after 4 wk (7%; P < 0.05). The largest nonsignificant reduction (15%) occurred in the women with the TT genotype after 4 wk of MTHF supplementation. CONCLUSIONS: The response to tHcy-lowering therapy is influenced by MTHFR genotype. Women with the TT genotype seem to benefit the most from supplementation with either FA or MTHF. In women with the CT or CC genotype, FA is more effective than MTHF in lowering plasma tHcy.     

Folate status in Germany 1997-2000

Data about folate intake and blood values of the German population, published between 1997 and 2000, have been reviewed. Median folate intake is about 250 micrograms/day in the adult population, which indicates a high likelihood of inadequate intake when compared to the Estimated Average Requirement (EAR) of 320 micrograms/day. Only a few studies have evaluated serum and erythrocyte folate or plasma homocysteine as a marker of folate status. The most representative data show that 25% of German women of childbearing age have an inadequate recent folate intake. Only 13.3% of the women have red blood cell folate values above the critical value of 400 micrograms/day established by Daly et al (1995). Folic acid fortification of food is shown to be responsible for about 25% of folate intake in the German child and adolescent population in one study. If we extrapolate these data to the general population, folic acid fortification could be the explanation for the differences observed between folate intake and blood values. The discrepancy might also be explained by slight inaccuracies in food composition tables. Folate intake from fortified food or from supplements is not taken into account in most of the studies, which is a variable that can lead to confusion. Nutrition surveys should adapt official composition tables for local food patterns, and include fortified commercial foods, in order to make folate intake data more accurate. However, representative serum and erythrocyte folate values are lacking for most age groups. Before taking public health measures concerning folate fortification of food, the real folate status of the German population should be established.     

Early event-related potential changes during working memory activation predict rapid decline in mild cognitive impairment

BACKGROUND: The conversion of mild cognitive impairment (MCI) to Alzheimer's disease is associated with substantial compromise of neocortical circuits subserving rapid cognitive functions such as working memory. Event-related potential (ERP) analysis is a powerful tool to identify early impairment of these circuits, yet research for an electrophysiological marker of cognitive deterioration in MCI is scarce. Using a "2-back" activation paradigm, we recently described an electrophysiological correlate of working memory activation (positive-negative working memory [PN(wm)] component) over parietal electrodes. METHODS: Ours was a longitudinal study of 24 MCI patients with ERP analysis at inclusion and neuropsychological follow-up after 1 year. We used ERP waveform subtraction analysis between the n-back and control tasks. Analysis of variance (ANOVA) was used to compare electroencephalograph latencies between progressive MCI (PMCI) and stable MCI (SMCI), and univariate regression was used to assess the relationship between neuropsychological measures at baseline and clinical outcome. RESULTS: Thirteen (54%) MCI patients showed PMCI, and 11 (46%) remained stable (SMCI). In SMCI, a PN(wm) component with significantly larger density compared to baseline was identified when subtracting the detection task for both the 1- and 2-back tasks. In contrast, in PMCI, the PN(wm) component was absent in both 1-back and 2-back conditions. Neuropsychological variables and n-back test performance at inclusion did not predict cognitive deterioration 1 year later. CONCLUSIONS: In conjunction with recent functional imaging data, the present results support the notion of an early dysfunction of neural generators within the parietal cortex in MCI. They also reveal that the absence of the PN(wm) component may provide an easily applicable qualitative predictive marker of rapid cognitive deterioration in MCI.     

Development and characterization of a 293 cell line with regulatable expression of the hepatitis B virus large envelope protein

During the life cycle of hepatitis B virus (HBV) the large L envelope protein plays a pivotal role that is related to its peculiar dual transmembrane topology. To study the complex structure and diverse functions of L under regulated conditions of production, a human 293 cell line stably expressing L under the control of the ecdysone-inducible promoter was generated. Cells demonstrated stringent dose- and time-dependent kinetics of induction with undetectable background expression in the absence of the inducer. Temporal control of L expression allowed to trace (i) its posttranslational reorientation resulting in the mixed topology; (ii) its spatial redistribution from the endoplasmic reticulum to Golgi-like structures; and (iii) its intracellular retention in a membrane-associated configuration. On regulated overproduction, L blocked the secretion of HBV small envelope polypeptides without impairing the cell secretory apparatus. Despite the continuous high-level storage of L within the 293 cell line, no cytopathic effects could be detected. This is in contrast to ground-glass hepatocytes of chronic HBV carriers and HBV transgenic mice and may imply that the intracellular storage of L is particularly damaging to the liver cell.