Therapeutic innovations in inflammatory bowel diseases.

Inflammatory bowel disease (IBD) is a spectrum of complex multifactorial immune disorders characterized by chronic inflammation of the gut. Significant advances have been made in unraveling the pathogenesis of this disease spectrum, which have spurred the discovery of new therapeutic targets and strategies. In this review, we highlight the emerging new classes of IBD therapeutics under clinical evaluation and their method of action, including JAK inhibitors, anti-SMAD7 oligonucleotides, and cell-based therapies. Moreover, we discuss how an approach based on unique molecular insights in a given patient will, in the future, lead to a truly individualized/tailored disease management, starting at diagnosis, aiding in prognosis, and resulting in a personalized therapeutic approach.

How often did Belgian physicians co-prescribe tamoxifen with strong CYP2D6 inhibitors over the last 6 years?

AIMS: Tamoxifen is widely used in the treatment of breast cancer. It is a pro-drug metabolized to the more active endoxifen through CYP2D6. Concomitant intake of CYP2D6 inhibitors results in lower endoxifen levels and could influence efficacy. The objective of this study was to evaluate the evolution of co-prescription of tamoxifen and CYP2D6 inhibitors in Belgium. METHODS: Data were retrieved from the Pharmanet database of the National Institute for Health and Disability Insurance for the period January 2006-December 2009. For the analysis of the evolution of the co-prescription, the period was divided in subperiods of 2 months. The category tamoxifen+CYP2D6 inhibitor was defined as women who were delivered tamoxifen and a CYP2D6 inhibitor in that subperiod. The results were validated on the period December 2011-May 2012. RESULTS: The percentage of co-prescription decreased over time for the strong CYP2D6 inhibitors and increased for the weak CYP2D6 inhibitor, with these trends persisting in 2012. Tamoxifen and CYP2D6 inhibitors were mostly prescribed by general practitioners and gynaecologists and by general practitioners and psychiatrists, respectively. DISCUSSION: This study shows that a proportion of women taking tamoxifen in Belgium are prescribed a strong CYP2D6 inhibitor, which could affect tamoxifen efficacy. Over time, the concomitant intake decreased. Paroxetine was the most prescribed strong CYP2D6 inhibitor. Venlafaxine, a weak CYP2D6 inhibitor, was prescribed more often. This study also shows that tamoxifen and the CYP2D6 inhibitors are not only prescribed by physicians specialized in breast cancer; therefore, all physicians should be aware of this interaction.

BNIP3 supports melanoma cell migration and vasculogenic mimicry by orchestrating the actin cytoskeleton.

BNIP3 is an atypical BH3-only member of the BCL-2 family of proteins with reported pro-death as well as pro-autophagic and cytoprotective functions, depending on the type of stress and cellular context. In line with this, the role of BNIP3 in cancer is highly controversial and increased BNIP3 levels in cancer patients have been linked with both good as well as poor prognosis. In this study, using small hairpin RNA (shRNA) lentiviral transduction to stably knockdown BNIP3 (BNIP3-shRNA) expression levels in melanoma cells, we show that BNIP3 supports cancer cell survival and long-term clonogenic growth. Although BNIP3-shRNA increased mitochondrial mass and baseline levels of reactive oxygen species production, which are features associated with aggressive cancer cell behavior, it also prevented cell migration and completely abolished the ability to form a tubular-like network on matrigel, a hallmark of vasculogenic mimicry (VM). We found that this attenuated aggressive behavior of these melanoma cells was underscored by severe changes in cell morphology and remodeling of the actin cytoskeleton associated with loss of BNIP3. Indeed, BNIP3-silenced melanoma cells displayed enhanced formation of actin stress fibers and membrane ruffles, while lamellopodial protrusions and filopodia, tight junctions and adherens junctions were reduced. Moreover, loss of BNIP3 resulted in re-organization of focal adhesion sites associated with increased levels of phosphorylated focal adhesion kinase. Remarkably, BNIP3 silencing led to a drop of the protein levels of the integrin-associated protein CD47 and its downstream signaling effectors Rac1 and Cdc42. These observations underscore that BNIP3 is required to maintain steady-state levels of intracellular complexes orchestrating the plasticity of the actin cytoskeleton, which is integral to cell migration and other vital processes stimulating cancer progression. All together these results unveil an unprecedented pro-tumorigenic role of BNIP3 driving melanoma cell's aggressive features, like migration and VM.

The neuronal migration defect in mice with Zellweger syndrome (Pex5 knockout) is not caused by the inactivity of peroxisomal beta-oxidation.

The purpose of this study was to investigate whether deficient peroxisomal beta-oxidation is causally involved in the neuronal migration defect observed in Pex5 knockout mice. These mice are models for Zellweger syndrome, a peroxisome biogenesis disorder. Neocortical development was evaluated in mice carrying a partial or complete defect of peroxisomal beta-oxidation at the level of the second enzyme of the pathway, namely, the hydratase-dehydrogenase multifunctional/bifunctional enzymes MFP1/L-PBE and MFP2/D-PBE. In contrast to patients with multifunctional protein 2 deficiency who present with neocortical dysgenesis, impairment of neuronal migration was not observed in the single MFP2 or in the double MFP1/MFP2 knockout mice. At birth, the double knockout pups displayed variable growth retardation and about one half of them were severely hypotonic, whereas the single MFP2 knockout animals were all normal in the perinatal period. These results indicate that in the mouse, defective peroxisomal beta-oxidation does not cause neuronal migration defects by itself. This does not exclude that the inactivity of this metabolic pathway contributes to the brain pathology in mice and patients with complete absence of functional peroxisomes.

Characterisation of human peroxisomal 2,4-dienoyl-CoA reductase.

Based on the primary structure of the rat peroxisomal 2,4-dienoyl-CoA reductase (M. Fransen, P.P. Van Veldhoven, S. Subramani, Biochem. J. 340 (1999) 561-568), the cDNA of the human counterpart was cloned. It contained an open reading frame of 878 bases encoding a protein of 291 amino acids (calculated molecular mass 30778 Da), being 83% identical to the rat reductase. The gene, encompassing nine exons, is located at chromosome 16p13. Bacterially expressed poly(His)-tagged reductase was active not only towards short and medium chain 2,4-dienoyl-CoAs, but also towards 2,4,7,10,13,16,19-docosaheptaenoyl-CoA. Hence, the reductase does not seem to constitute a rate limiting step in the peroxisomal degradation of docosahexaenoic acid. The reduction of docosaheptaenoyl-CoA, however, was severely decreased in the presence of albumin.

Triple Test Screening for Down Syndrome: Looking Back on a False-Positive Result and Having or Not Having a Triple Test in Subsequent Pregnancies.

Objectives: It was the main aim of the present retrospective study carried out in Flanders to evaluate how women with a false-positive triple test result look back on their experience and decision making and how many of them make use of the triple test in subsequent pregnancies. Methods: All 508 women tested in the Centre for Human Genetics in Leuven in 1995 who had a positive triple test result followed by a normal amniocentesis outcome were invited to participate in a mailed questionnaire study with open and multiple choice questions in 1998. The response rate was 68%. Results: The answers to the multiple choice question assessing how they look back on their initial expectations regarding the exact meaning of the triple test revealed that less than one half reported that it concerned the identification of 'a higher risk of carrying a child with Down syndrome (DS)'. Reporting correct initial expectations was significantly associated with a higher education level. The same holds for indecisiveness regarding pregnancy termination should the amniocentesis have detected a fetus with DS. As expected, a large majority of the women reported a high level of distress or worry after the communication of the positive triple test result. Overall the findings show that retrospectively most women had the feeling that the decision to have amniocentesis was their own decision rather than a professional's. Of the subgroup with one or more subsequent pregnancies 70% had another triple test. Conclusions: The overall results of this study clearly reveal a need for a systematic approach aimed at better informing and counselling pregnant women about the implications and limitations of the triple test. Notwithstanding the reported high level of distress caused by a positive triple test result, a large majority of the women with subsequent pregnancies had another triple test; they represent a clearly higher percentage than in another recent study. Copyright 2001 S. Karger AG, Basel

Mitochondrial and peroxisomal targeting of 2-methylacyl-CoA racemase in humans.

2-Methylacyl-CoA racemase is an auxiliary enzyme required for the peroxisomal beta-oxidative breakdown of (2R)-pristanic acid and the (25R)-isomer of C(27) bile acid intermediates. The enzyme activity is found not only in peroxisomes but also is present in mitochondria of human liver and fibroblasts. The C terminus of the human racemase, a protein of 382 amino acids with a molecular mass of 43,304 daltons as deduced from its cloned cDNA, consists of KASL. Hitherto this sequence has not been recognized as a peroxisomal targeting signal (PTS1). From the in vitro interaction between recombinant racemase and recombinant human PTS1 receptor (Pex5p), and the peroxisomal localization of green fluorescent protein (GFP) fused to the N terminus of full-length racemase or its last six amino acids in tranfected Chinese hamster ovary (CHO) cells, we concluded that ASL is a new PTS1 variant. To be recognized by Pex5p, however, the preceding lysine residue is critical. As shown in another series of transfection experiments with GFP fused to the C terminus of the full-length racemase or racemase with deletions of the N terminus, mitochondrial targeting information is localized between amino acids 22 and 85.Hence, our data show that a single transcript gives rise to a racemase protein containing two topogenic signals, explaining the dual cellular localization of the activity.

Parenting stress and psychosocial well-being among parents with twins conceived naturally or by reproductive technology.

This study compared parenting stress and psychosocial well-being among parents with 1 year old twins conceived in three different ways: (i) spontaneously without any medical assistance (54 families), (ii) spontaneously following hormonal treatment (25 families) and (iii) following in-vitro fertilization (IVF) or artificial insemination (AI) with the semen of the social father (24 families). The investigation included the Parenting Stress Index (PSI) and the General Health Questionnaire (GHQ-30). Since the presence of older children differed significantly between the three groups, this factor was included in the statistical analysis. Overall, no significant differences were found between the three study groups, either for the mothers or for the fathers. Nevertheless, we found a main effect of the presence of older children and an interaction effect of the presence of older children and the conception mode on some of the scales for the mothers: first-time mothers showed significantly higher stress related to parental competence, health and the partner relationship compared with mothers who had older children. First-time mothers with a history of infertility obtained significantly higher stress scores for parental competence and health and showed lower psychosocial well-being compared with naturally conceiving first-time mothers and mothers with a history of infertility who already had children.

Feelings and the need for information and counselling of expectant parents of twins.

In this study, expectant parents of twins were questioned about their feelings and need for information and counselling on the parenting of twins. Data were obtained from self-rating questionnaires and an interview with the expectant mother. From the results it is argued that expectant parents of twins need specific information and counselling about the medical, emotional and parenting issues of having twins. Guidelines for organising this counselling are proposed.