Lysyl oxidase activity regulates oncogenic stress response and tumorigenesis

Cellular senescence, a stable proliferation arrest, is induced in response to various stresses. Oncogenic stress-induced senescence (OIS) results in blocked proliferation and constitutes a fail-safe program counteracting tumorigenesis. The events that enable a tumor in a benign senescent state to escape from OIS and become malignant are largely unknown. We show that lysyl oxidase activity contributes to the decision to maintain senescence. Indeed, in human epithelial cell the constitutive expression of the LOX or LOXL2 protein favored OIS escape, whereas inhibition of lysyl oxidase activity was found to stabilize OIS. The relevance of these in vitro observations is supported by in vivo findings: in a transgenic mouse model of aggressive pancreatic ductal adenocarcinoma (PDAC), increasing lysyl oxidase activity accelerates senescence escape, whereas inhibition of lysyl oxidase activity was found to stabilize senescence, delay tumorigenesis, and increase survival. Mechanistically, we show that lysyl oxidase activity favors the escape of senescence by regulating the focal-adhesion kinase. Altogether, our results demonstrate that lysyl oxidase activity participates in primary tumor growth by directly impacting the senescence stability.

VE-statin/egfl7 expression in endothelial cells is regulated by a distal enhancer and a proximal promoter under the direct control of Erg and GATA-2

Angiogenesis is the process by which new blood vessels arise from existing ones by the budding out of endothelial cell capillaries from the luminal side of blood vessels. Blood vessel formation is essential for organ development during embryogenesis and is associated with several physiological and pathological processes, such as wound healing and tumor development. The VE-statin/egfl7 gene is specifically expressed in endothelial cells during embryonic development and in the adult. We studied here the regulatory mechanisms that control this tissue-specific expression. RT-qPCR analyses showed that the specificity of expression of VE-statin/egfl7 in endothelial cells is not shared with its closest neighbor genes notch1 and agpat2 on the mouse chromosome 2. Chromatin-immunoprecipitation analysis of histone modifications at the VE-statin/egfl7 locus showed that the chromatin is specifically opened in endothelial cells, but not in fibroblasts at the transcription start sites. A 13 kb genomic fragment of promoter was cloned and analyzed by gene reporter assays which showed that two conserved regions are important for the specific expression of VE-statin/egfl7 in endothelial cells; a −8409/−7563 enhancer and the −252/+38 region encompassing the exon-1b transcription start site. The latter contains essential GATA and ETS-binding sites, as assessed by linker-scanning analysis and site-directed mutagenesis. An analysis of expression of the ETS and GATA transcription factors showed that Erg, Fli-1 and GATA-2 are the most highly expressed factors in endothelial cells. Erg and GATA-2 directly control the expression of the endogenous VE-statin/egfl7 while Fli-1 probably exerts an indirect control, as assessed by RNA interference and chromatin immunoprecipitation. This first detailed analysis of the mechanisms that govern the expression of the VE-statin/egfl7 gene in endothelial cells pinpoints the specific importance of ETS and GATA factors in the specific regulation of genes in this cell lineage.

Deficiency in the p110alpha subunit of PI3K results in diminished Tie2 expression and Tie2(-/-)-like vascular defects in mice

Phosphoinositide 3-kinase (PI3K) is activated by transmembrane tyrosine kinases such as vascular endothelial growth factor (VEGF) receptors and Tie2 (tunica intima endothelial kinase 2), both of which are key regulators of vascular development. However, the in vivo role of PI3K during developmental vascularization remains to be defined. Here we demonstrate that mice deficient in the p110alpha catalytic subunit of PI3K display multiple vascular defects, including dilated vessels in the head, reduced branching morphogenesis in the endocardium, lack of hierarchical order of large and small branches in the yolk sac, and impaired development of anterior cardinal veins. These vascular defects are strikingly similar to those in mice defective in the Tie2 signaling pathway. Indeed, Tie2 protein levels were significantly lower in p110alpha-deficient mice. Furthermore, RNA interference of p110alpha in cultured endothelial cells significantly reduced Tie2 protein levels. These findings raise the possibility that PI3K may function as an upstream regulator of Tie2 expression during mouse development.

Couple formation and fertility outside marriage in Great Britain: differences and similarities with the French situation

"In this paper, we shall attempt to give a detailed presentation of the recent evolution of the mechanisms of family formation in Great Britain. Basing our investigations on an original use of retrospective longitudinal data, we shall, in effect, explore the changes in the behaviours of successive generations and, as far as possible, relate these to comparable data on the French situation. This study aims at a more specific analysis of the respective evolutions in the two countries in order to show how, despite similarities in trends, these evolutions remain profoundly marked by their own socio-political and cultural traits. This will also bring to light the differences and similarities between France and Great Britain in family formation and, more specifically, in the evolution of extra-marital births and cohabitation."

[Definitive migration to France and family constitution]

Data from a survey of 383 individuals, either aliens or naturalized citizens, aged 45-69 residing in France in 1981 are used to examine the relationship between migration and the family life cycle. The results indicate that "marriage, which is an obstacle to migration for women born before 1915, actually favours migration in later generations. Furthermore, the [fertility] of naturalized citizens (2.64 children per woman) is shown to be markedly lower than that of foreigners (3.67) and approaches the national level of that period (2.60) in a few years only." (SUMMARY IN ENG AND SPA)

[New perspectives in life-event history analysis]

"In the last decade, life-event history analysis, also called failure time data analysis or survival analysis, has been widely adopted by demographers. This methodology in demography allows [us] to overcome major hurdles especially when analyzing longitudinal survey data. This paper describes the new perspectives opened to research in that field, and is illustrated by new results and examples of research projects. The authors concentrate on four issues: the analysis of incorrect and imperfect data, the analysis based on more complex data and lastly the study of interaction between phenomena." (SUMMARY IN ENG AND SPA)

Residential mobility in France and in Paris since 1945: the history of a cohort

Using data from two retrospective surveys carried out in France in 1981 and 1986, the authors "reconstitute the residential history of a cohort and...measure the differences [in migration histories] between Paris and the whole of France.... We shall attempt to reconstruct the residential histories of these individuals, by analysing firstly the stage when they left their parents to set up their first independent home, and secondly mobility throughout their life course, paying particular attention to the extension of home ownership in this cohort."

The event history approach in demography

"In the present paper, we shall examine...changes in the field of demography, by following the progression from period analysis to cohort analysis. We shall discuss the hypotheses underlying each of these approaches and show how their distance from actual human behaviour could lead to mistaken or incomplete conclusions. We shall then show how event history analysis can solve these problems and we shall define the hypotheses implied by this new approach. Finally, we shall come back to the complimentarity of the different social sciences."

T(h)2 cytokine dependence of IgD production by normal human B cells

IgD is a minor component of serum Ig and the control of IgD secretion is virtually unknown. We measured concentrations of IgD (and IgE and IgM as controls) in culture supernatants of peripheral blood mononuclear cells (PBMC) from 60 normal donors as well as mononuclear cells from 10 tonsils following culture in the absence or presence of CD40 mAb and cytokines. Low levels of IgD were measured in cultures of PBMC, either unstimulated or stimulated by anti-CD40 antibodies. IL-4 and IL-10 significantly increased IgD production by CD40 mAb-stimulated cells in the majority of normal subjects studied, whereas in a limited number of individuals, spontaneous IgD production was either low or high, but with no increase upon stimulation. Spontaneous IgD production by tonsil-derived mononuclear cells was higher than by PBMC and increased after CD40 stimulation and even more in the presence of IL-10, but not IL-4. IL-2 and IFN-gamma exerted a dose-dependent inhibition on spontaneous as well as CD40- and cytokine-induced IgD production by PBMC, but not by tonsil mononuclear cells. Activation by IL-4 of CD40-stimulated purified B cells from tonsil and PBMC, and by IL-10 of tonsil B cells increased IgD production, whereas IL-2 and IFN-gamma had no detectable inhibitory effect. This suggests that accessory cells indirectly regulate IgD synthesis. IgD production induced in PBMC by IL-4 or IL-10 appeared to result from an active synthesis, and correlated with an increase in the number of IgD-containing plasma cells as demonstrated by immunofluorescence and increased expression of secreted IgD transcripts. These findings suggest that IgD production by normal peripheral blood human B cells is regulated positively by T(h)2 cytokines and negatively by T(h)1 cytokines.

Preincubation of human resting T cell clones with interleukin 10 strongly enhances their ability to produce cytokines after stimulation

Interleukin 10 (IL-10) has been described as a cytokine inhibitory factor downregulating IL-2 secretion and inducing T cell anergy. The data reported in this study show that preincubation of resting T cells from the human CD4+ clone SP-B21 (and clone TA-23.6) with IL-10 strongly enhances their capacity to further produce IL-2, interferon gamma (IFN-gamma), IL-4 and tumour necrosis factor alpha (TNF-alpha) after subsequent activation. In contrast, when IL-10 was added during the activation step, the previously reported specific inhibition of IL-2 synthesis was observed. Flow cytometric analysis of intracellular IL-2- and IL-4-producing cells revealed that preincubation with IL-10 increased the number of cytokine-producing cells, but did not affect their individual ability to produce these cytokines. We further show that IL-10 plays a dose-dependent role of viability maintenance factor. This effect relates to a direct anti-apoptotic effect of IL-10, which is likely independent of the expression of bcl-2, bcl-x and fas. Such paradoxal properties of IL-10 on T cells should be considered when aiming at using IL-10 as an immunosuppressive molecule in the treatment of diseases.

The transformation of housing and household structures in France and Great Britain

"In France and Great Britain, the last 30 years have seen considerable evolution in the housing stock...and in household structure....This article describes the dynamic interaction of processes influencing the evolution of both households and dwellings. In the two countries, the life course of individuals has become more and more complex. This translates into an ever greater variety of housing needs, not only at different stages in family life, but also in relation to growing job insecurity regardless of family situation. At the same time, policies encouraging home-ownership seem to have reached their limits, because of the new demand for rented accommodation. The answer to sociological and economic evolution cannot be found in a ¿single' type of housing and tenure status, but rather in a wide range of dwellings and in the development of a more flexible housing market."

Radioimmunoassay for the measurement of S9788 in serum and microdialysis samples

S9788, 6-[4-(2,2-di-(fluorophenyl)-ethylaminol-1-piperdinyl]-N,N'-d i-2-propenyl-1, 3,5-triazine- 2, 4-diamine, is a novel compound designed to reverse tumour multidrug resistance associated with cancer chemotherapy. A specific and sensitive radioimmunoassay has been developed for the analysis of S9788 in serum samples and adapted for samples obtained by microdialysis. The limit of quantitation is 0.2 ng ml-1 in perfusion medium and there is no cross reactivity of the antibody with known metabolites of the parent compound or with certain cytotoxic compounds likely to be coadministered with S9788. Maximum probe recovery during microdialysis was 66% at a flow of 1 microliter min-1, using Ringer/BSA (70 mg ml-1) as the perfusion medium. The assay has sufficient sensitivity, precision, accuracy and specificity for the analysis of rat and human serum and microdialysis perfusate samples. The assay has been successfully applied to the determination of S9788 in rat plasma (total concentration) and the microdialysate of the same samples.

Human pharmacokinetics of a new Vinca alkaloid S 12363 with use of a monoclonal antibody-based radio- or enzyme immunoassay

S 12363 is a new Vinca alkaloid derivative, characterized by the grafting of an alpha-aminophosphonate, onto the Vinca nucleus, facilitating drug penetration and increasing intracellular drug retention. As a high cytotoxic activity had been demonstrated in in vitro and in vivo models recommended by the National Cancer Institute, a phase I trial was initiated in cancer patients. In order to quantify S 12363 systemic levels in humans, two monoclonal antibody-based immunoassays, RIA (radio-) and EIA (enzyme immunoassay) were developed. The gamma-emitting probe used in the RIA, 125I-(deacetyl-O4-vinblastine)-tyramine, bound very tightly to the monoclonal antibody (dissociation constant, Kd = 2.5 x 10(-11) M), demonstrating a high affinity mainly directed toward the catharantine nucleus (vindesine, vincristine, vinblastine, 100% cross-reactivity; vinorelbine, 0.3% cross-reactivity). In the EIA, a deacetyl O4-vinblastine/ovalbumine conjugate was used as the competing antigen. Its binding to the monoclonal antibody was revealed by an anti-mouse immunoglobulin G conjugated to biotin which interacts with streptavidin labeled with alkaline phosphatase. This method permitted obtaining nearly the same sensitivity and reproducibility with EIA as with RIA, their respective minimum quantitation limits being 0.100 and 0.040 ng/ml (106 and 42 pM) of S 12363 in plasma. These assays allowed the study of S 12363 systemic pharmacokinetics in cancer patients during a phase I trial up to 72 h after dosing. As determined by RIA, the S 12363 plasma profile was triphasic with a terminal half-life; t1/2 gamma = 49 +/- 16 h, a plasma clearance, CL = 0.14 +/- 0.04 liter/h/kg, and a volume of distribution at steady state, Vdss = 5.0 +/- 2.8 liter/kg. The pharmacokinetics of S 12363 is linearly related to dose when increased from 0.08 up to 0.84 mg/m2 in humans. Its plasma profile and pharmacokinetic parameters are close to those of other Vinca alkaloids with clearance and terminal half-life being intermediate between those of vinblastine and vincristine. Therapeutic doses are 4 to 10 times lower and should be a direct consequence of the higher uptake and retention by the cells of this new aminophosphonate Vinca alkaloid derivative.

Extra-marital births occurring in cohabiting unions

"Accompanying the rapid rise of unmarried cohabitation and the decline in nuptiality, Britain experienced a sharp increase in the number and proportion of births outside wedlock....84% of this recent increase corresponds to jointly registered births which can therefore be assumed to occur to informal couples. This chapter explores this new fertility trend using General Household Survey data for 1989, focusing on first births to single never-married cohabitants. The informality of cohabitation as a living arrangement and shortfalls in the data...are discussed....The chapter then attempts to provide some insights into the circumstances of the first birth, the timing of birth and marriage and the relative levels of fertility in the different unions."

Radioimmunoassays for a new angiotensin-converting enzyme inhibitor, zabicipril, and its active metabolite, zabiciprilat, in human plasma

Zabicipril (Z), a new angiotensin-converting-enzyme inhibitor under development, is a prodrug that has to be deesterified in vivo to the active metabolite, zabiciprilat (ZT), to reach its antihypertensive pharmacological properties. Two radioimmunoassays have been developed for the measurement of both Z and ZT in human plasma. Anti-Z and anti-ZT antibodies were raised in rabbits against their respective lysine analogues conjugated to bovine serum albumin. [3H]Z and [3H]ZT were used as radioligands for the prodrug (Z) and the drug (ZT), respectively. Studies on anti-Z antiserum specificity showed no significant cross-reactivity (< 0.1%) with the active metabolite (ZT); similarly, Z is poorly recognized (0.5%) by the anti-ZT antiserum. Both antisera showed little cross-reaction (2%) with glucuronide metabolites. The sensitivities of the assays were 1 and 0.2 ng/mL for Z and ZT, respectively. Interassay coefficients of variation ranged from 9 to 12% for Z at 2-50 ng/mL and from 8 to 13% for ZT at 0.5-5 ng/mL. These assays were used to investigate the pharmacokinetic profile of both Z and its pharmacologically active metabolite ZT after intravenous infusion of Z in human volunteers.

[A biographical approach to demography]

The merits of a biographical approach to demographic analysis are examined using survey data. "The analysis of complex interaction between diverse phenomena, using bivariate or multivariate models has been elaborated, and it allows the discovery of various types of dependence between events (reciprocal or unilateral) or of their independence. At this stage, heterogeneity of the observed populations was introduced, with the help of parametric or semi-parametric models, which point out the different strategies followed. The problems caused by non-observed heterogeneity have been partially solved but interdisciplinary collaboration would now appear to be necessary." (SUMMARY IN ENG AND GER AND SPA)