A randomized trial comparing omega-3 fatty acid plasma levels after ingestion of emulsified and non-emulsified cod liver oil formulations.

OBJECTIVES: Emulsified formulations of omega-3 fatty acids may increase plasma concentrations of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) compared with non-emulsified formulations. The current study evaluated plasma concentrations of DHA + EPA as well as DHA and EPA individually following administration of emulsified vs non-emulsified cod liver oil formulations. METHODS: In this randomized, 2-period, crossover study (ClinicalTrials.gov NCT02428699), 47 healthy adults received single doses of an emulsified cod liver oil formulation and a non-emulsified cod liver oil formulation, each containing 10% cod liver oil plus 10% cod oil and closely matched DHA and EPA content. Blood samples were collected for 24 h after dosing to analyze DHA and EPA plasma concentrations using a validated methodology. DHA + EPA, DHA, and EPA pharmacokinetics were compared using an analysis of covariance model. The incremental area under the plasma concentration curve at 24 h (iAUC0-24 h) for DHA + EPA was the primary endpoint. RESULTS: DHA + EPA, DHA, and EPA plasma concentrations reached higher levels in plasma following administration of the emulsified vs non-emulsified formulation. The emulsified cod liver oil formulation produced iAUC0-24 h values for DHA + EPA, DHA, and EPA that were 1.66, 1.78, and 1.64 times higher, respectively, than the non-emulsified formulation; iAUC0-10 h values were 1.84, 1.96, and 1.79 times higher, respectively (all p < 0.01). Maximum concentrations of DHA + EPA, DHA, and EPA in plasma were significantly higher for the emulsified than the non-emulsified formulation (p < 0.001). CONCLUSIONS: DHA + EPA, DHA, and EPA plasma concentrations were significantly higher for the emulsified cod liver oil supplement vs the reference non-emulsified cod liver oil supplement.

Clinical and Vitamin Response to a Short-Term Multi-Micronutrient Intervention in Brazilian Children and Teens: From Population Data to Interindividual Responses.

SCOPE: Micronutrients are in small amounts in foods, act in concert, and require variable amounts of time to see changes in health and risk for disease. These first principles are incorporated into an intervention study designed to develop new experimental strategies for setting target recommendations for food bioactives for populations and individuals. METHODS AND RESULTS: A 6-week multivitamin/mineral intervention is conducted in 9-13 year olds. Participants (136) are (i) their own control (n-of-1); (ii) monitored for compliance; (iii) measured for 36 circulating vitamin forms, 30 clinical, anthropometric, and food intake parameters at baseline, post intervention, and following a 6-week washout; and (iv) had their ancestry accounted for as modifier of vitamin baseline or response. The same intervention is repeated the following year (135 participants). Most vitamins respond positively and many clinical parameters change in directions consistent with improved metabolic health to the intervention. Baseline levels of any metabolite predict its own response to the intervention. Elastic net penalized regression models are identified, and significantly predict response to intervention on the basis of multiple vitamin/clinical baseline measures. CONCLUSIONS: The study design, computational methods, and results are a step toward developing recommendations for optimizing vitamin levels and health parameters for individuals.

B vitamin polymorphisms and behavior: evidence of associations with neurodevelopment, depression, schizophrenia, bipolar disorder and cognitive decline.

The B vitamins folic acid, vitamin B12 and B6 are essential for neuronal function, and severe deficiencies have been linked to increased risk of neurodevelopmental disorders, psychiatric disease and dementia. Polymorphisms of genes involved in B vitamin absorption, metabolism and function, such as methylene tetrahydrofolate reductase (MTHFR), cystathionine ß synthase (CßS), transcobalamin 2 receptor (TCN2) and methionine synthase reductase (MTRR), have also been linked to increased incidence of psychiatric and cognitive disorders. However, the effects of these polymorphisms are often quite small and many studies failed to show any meaningful or consistent associations. This review discusses previous findings from clinical studies and highlights gaps in knowledge. Future studies assessing B vitamin-associated polymorphisms must take into account not just traditional demographics, but subjects' overall diet, relevant biomarkers of nutritional status and also analyze related genetic factors that may exacerbate behavioral effects or nutritional status.

Improved growth of toddlers fed a milk containing synbiotics.

Bifidobacterium longum (BL999), Lactobacillus rhamonosus (LPR), prebiotics (inulin and fructo-oligosaccharides), and long-chain polyunsaturated fatty acids (LCPUFA) are believed to have health benefits. In a randomized, double-blind, controlled trial we compared growth and development of toddlers fed milk containing synbiotics (BL999, LPR, and prebiotics) and LCPUFA or a control milk. Three hundred and ninety three healthy, 12 month-old toddlers were fed approximately 400 mL/day for 12 months. Anthropometric measurements were taken at 12, 14, and 16 months. Toddlers' response to measles and hepatitis A vaccine was measured at 16 months, and Bayley scale for motor, cognitive, and behavioral functions made at 24 months. The primary outcome was weight gain between 12 and 16 months. Secondary outcomes were gain in length, head circumference, and body mass index, gastrointestinal tolerance (stool characteristics), stool bacterial counts, safety, anti-vaccine IgG, and neurodevelopment. Weight gain was greater in the synbiotics group (mean±SD, 7.57±4.13 g/day) compared with the control group (6.64±4.08 g/day). The difference of 0.93 g/day (with a 95% confidence interval of 0.12 to 1.75) is significant (p=0.025). The gain in the synbiotics group resulted in a change in z-score weight-for-age closer to WHO Child Growth Standard. There was a significant increase in lactobacilli and enterococci counts between 12 months and 16 months in the synbiotic group. We conclude that in healthy toddlers milk containing synbiotics and LCPUFA provides better growth and promotes favorable gut colonization, as shown by higher Lactobacillus counts.

Effect of a whey-predominant starter formula containing LCPUFAs and oligosaccharides (FOS/GOS) on gastrointestinal comfort in infants.

Development of new infant formulas aims to replicate the benefits of breast milk. One benefit of breast milk over infant formulas is greater gastrointestinal comfort. We compared indicators of gastrointestinal comfort in infants fed a whey-predominant formula containing long-chain polyunsaturated fatty acids, galacto-oligo-saccharides and fructo-oligosaccharides, and infants fed a control casein-predominant formula without additional ingredients. The single-centre, prospective, double-blind, controlled trial randomly assigned healthy, full-term infants (n=144) to receive exclusively either experimental or control formula from 30 days to 4 months of age. A group of exclusively breast-fed infants served as reference (n=80). At 1, 2, 3, and 4 months, infants' growth parameters were measured and their health assessed. Parents recorded frequency and physical characteristics of infants' stool, frequency of regurgitation, vomiting, crying and colic. At 2-months, gastric emptying (ultrasound) and intestinal transit time (H2 breath test) were measured, and stool samples collected for bacterial analysis. Compared to the control (n=69), fewer of the experimental group (n=67) had hard stools (0.7 vs 7.5%, p<0.001) and more had soft stools (90.8 vs 82.3%, p<0.05). Also compared to the control, the experimental group's stool microbiota composition (mean % bifidobacteria: 78.1 (experimental, n=17), 63.7 (control, n=16), 74.3 (breast-fed, n=20), gastric transit times (59.6 (experimental, n=53), 61.4 (control, n=62), 55.9 (breast-fed, n=67) minutes) and intestinal transit times (data not shown) were closer to that of the breast-fed group. Growth parameter values were similar for all groups. The data suggest that, in infants, the prebiotic-containing whey-based formula provides superior gastrointestinal comfort than a control formula.

Preclinical evaluation of nilotinib efficacy in an imatinib-resistant KIT-driven tumor model.

The novel KIT inhibitor nilotinib is currently being evaluated for its clinical utility in the treatment of gastrointestinal stromal tumor. However, the effects of nilotinib in cells expressing commonly occurring KIT mutations remain to be fully defined. The aim of this study was therefore to investigate the efficacy of nilotinib against cells expressing imatinib-sensitive or imatinib-resistant KIT mutations and to evaluate [(18)F] fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging as a biomarker of nilotinib response in vivo. Nilotinib inhibited the proliferation of imatinib-responsive V560G-KIT FDC-P1 and imatinib-resistant D816V-KIT FDC-P1 cells with a GI(50) of 4.9 and 630 nmol/L, respectively, whereas apoptosis studies revealed that nilotinib and imatinib were equipotent against the V560G cell line. In contrast, although 10 micromol/L nilotinib induced >50% apoptosis in the D816V cells at 16 hours, 10 micromol/L imatinib had no effect on cell survival at 24 hours. Syngeneic DBA2/J mice bearing FDC-P1-KIT tumors were evaluated for response to nilotinib by FDG-PET. V560G-KIT FDC-P1 tumor FDG uptake was significantly reduced compared with baseline levels following 2 days of nilotinib treatment. In contrast, no effect of nilotinib was observed on tumor growth or FDG-PET uptake into D816V tumors despite intratumoral drug levels reaching in excess of 10 micromol/L at 4 hours after dosing. Biomarker analysis revealed the inhibition of KIT phosphorylation in V560G but not D816V tumors. These findings show the in vivo activity of nilotinib in the treatment of tumors bearing V560G-KIT but not D816V-KIT and the utility of FDG-PET imaging to assess tumor response to this agent.

Gene expression profiling identifies activated growth factor signaling in poor prognosis (Luminal-B) estrogen receptor positive breast cancer.

BACKGROUND: Within estrogen receptor-positive breast cancer (ER+ BC), the expression levels of proliferation-related genes can define two clinically distinct molecular subtypes. When treated with adjuvant tamoxifen, those ER+ BCs that are lowly proliferative have a good prognosis (luminal-A subtype), however the clinical outcome of those that are highly proliferative is poor (luminal-B subtype). METHODS: To investigate the biological basis for these observations, gene set enrichment analysis (GSEA) was performed using microarray data from 246 ER+ BC samples from women treated with adjuvant tamoxifen monotherapy. To create an in vitro model of growth factor (GF) signaling activation, MCF-7 cells were treated with heregulin (HRG), an HER3 ligand. RESULTS: We found that a gene set linked to GF signaling was significantly enriched in the luminal-B tumors, despite only 10% of samples over-expressing HER2 by immunohistochemistry. To determine the biological significance of this observation, MCF-7 cells were treated with HRG. These cells displayed phosphorylation of HER2/3 and downstream ERK and S6. Treatment with HRG overcame tamoxifen-induced cell cycle arrest with higher S-phase fraction and increased anchorage independent colony formation. Gene expression profiles of MCF-7 cells treated with HRG confirmed enrichment of the GF signaling gene set and a similar proliferative signature observed in human ER+ BCs resistant to tamoxifen. CONCLUSION: These data demonstrate that activation of GF signaling pathways, independent of HER2 over-expression, could be contributing to the poor prognosis of the luminal-B ER+ BC subtype.

Sustained clinical responses to tyrosine kinase inhibitor sunitinib in thyroid carcinoma.

The limited therapeutic options available for patients with metastatic papillary thyroid carcinomas (PTC) and follicular thyroid carcinomas (FTC) necessitates the development of novel therapies. Identification of somatic rearrangements of the tyrosine kinase domain of the RET gene in PTC have improved our understanding of thyroid tumorigenesis. Sunitinib is active against the RET kinase and has both antineoplastic and antiangiogenic properties. Its role in the treatment of patients with thyroid carcinoma has yet to be evaluated in clinical trials. Two patients with progressive metastatic thyroid carcinoma (case 1: PTC, and case 2: FTC) were enroled in a phase I clinical trial to evaluate positron emission tomography (PET) in the monitoring of response to sunitinib. Tumour biopsies and PET were performed at baseline and 4 weeks after the commencement of sunitinib. Activation of the RET kinase pathway was evaluated using immunohistochemistry (IHC) and western blot analysis of total phosphorylated tyrosine and downstream signalling targets of the RET pathway. Both patients demonstrated sustained clinical responses to sunitinib over a duration of 4 years. In case 1, (PTC) PET confirmed evidence of a partial metabolic response, and IHC and western blot analysis demonstrated inhibition of the RET kinase pathway posttreatment. In case 2, (FTC) PET confirmed stable disease after sunitinib. IHC staining of the tumour showed low total phosphorylated tyrosine staining at baseline which did not change after treatment. These case studies highlight potential activity of sunitinib in patients with metastatic thyroid carcinoma. Sunitinib seems to be a promising agent in the treatment of thyroid cancers and this requires validation in future clinical trials.

A specific role for AKT3 in the genesis of ovarian cancer through modulation of G(2)-M phase transition.

Ovarian cancer is the major cause of death from gynecological malignancy, and there is an urgent need for new therapeutic targets. The phosphatidylinositol 3-kinase (PI3K)/AKT pathway has been strongly implicated in the genesis of ovarian cancer. However, to identify and evaluate potential targets for therapeutic intervention, it is critical to understand the mechanism by which the PI3K/AKT pathway facilitates ovarian carcinogenesis. Here, we show that AKT3 is highly expressed in 19 of 92 primary ovarian tumors. Strikingly, purified AKT3 exhibited up to 10-fold higher specific activity than AKT1, potentially amplifying the effects of AKT3 overexpression. Consistent with this finding, AKT3 levels in a range of ovarian cancer cell lines correlated with total AKT activity and proliferation rates, implicating AKT3 as a key mediator of ovarian oncogenesis. Specific silencing of AKT3 using short hairpin RNA markedly inhibited proliferation of the two cell lines with highest AKT3 expression and total AKT activity, OVCA429 and DOV13, by slowing G(2)-M phase transition. These findings are consistent with AKT3 playing a key role in the genesis of at least one subset of ovarian cancers.

Multi-tracer small animal PET imaging of the tumour response to the novel pan-Erb-B inhibitor CI-1033.

PURPOSE: This study was designed as "proof of concept" for a drug development model utilising multi-tracer serial small animal PET imaging to characterise tumour responses to molecularly targeted therapy. METHODS: Mice bearing subcutaneous A431 human squamous carcinoma xenografts (n=6-8) were treated with the pan-Erb-B inhibitor CI-1033 or vehicle and imaged serially (days 0, 3 and 6 or 7) with [(18)F]fluorodeoxyglucose, [(18)F]fluoro-L: -thymidine, [(18)F]fluoro-azoazomycinarabinoside or [(18)F]fluoromisonidazole. Separate cohorts (n=3) were treated identically and tumours were assessed ex vivo for markers of glucose metabolism, proliferation and hypoxia. RESULTS: During the study period, mean uptake of all PET tracers generally increased for control tumours compared to baseline. In contrast, tracer uptake into CI-1033-treated tumours decreased by 20-60% during treatment. Expression of the glucose transporter Glut-1 and cell cycle markers was unchanged or increased in control tumours and generally decreased with CI-1033 treatment, compared to baseline. Thymidine kinase activity was reduced in all tumours compared to baseline at day 3 but was sevenfold higher in control versus CI-1033-treated tumours by day 6 of treatment. Uptake of the hypoxia marker pimonidazole was stable in control tumours but was severely reduced following 7 days of CI-1033 treatment. CONCLUSION: CI-1033 treatment significantly affects tumour metabolism, proliferation and hypoxia as determined by PET. The PET findings correlated well with ex vivo biomarkers for each of the cellular processes studied. These results confirm the utility of small animal PET for evaluation of the effectiveness of molecularly targeted therapies and simultaneously definition of specific cellular processes involved in the therapeutic response.

An in vivo tumor model exploiting metabolic response as a biomarker for targeted drug development.

In vivo models that recapitulate oncogene-dependent tumorigenesis will greatly facilitate development of molecularly targeted anticancer therapies. We have developed a model based on activating mutations in c-KIT in gastrointestinal stromal tumors (GISTs). This model comprises murine tumors of FDC-P1 cell lines expressing c-KIT mutations that render the tumors either responsive (V560G) or resistant (D816V) to the small-molecule c-KIT inhibitor, imatinib. Clinically, GIST response to imatinib is associated with rapid reduction in fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET), preceding changes in conventional response criteria by several weeks. Using the FDC-P1 model in small animal PET, FDG uptake into tumors expressing the c-KIT V560G mutation was significantly reduced as early as 4 hours after imatinib treatment. In contrast, no change in FDG uptake was observed in resistant c-KIT D816V-expressing tumors after 48 hours of imatinib treatment. Consistent with the PET results, expression of the glucose transporter, GLUT1, was significantly reduced in V560G tumors at 4 hours, preceding changes in markers of proliferation by several hours. In vitro, imatinib treatment of V560G cells resulted in a reduction of glucose transporter numbers at the cell surface and decreased glucose uptake well before changes in cell viability. Notably, decreased ambient glucose concentrations enhanced the cytotoxic effect of imatinib. Taken together, these data account for the rapidity and significance of the PET response to imatinib and suggest that metabolic effects may contribute to imatinib cytotoxicity. Further, the FDC-P1 model represents a very useful paradigm for molecularly targeted drug development.

Direct identification of tyrosine 474 as a regulatory phosphorylation site for the Akt protein kinase.

Understanding the regulation of Akt has been of major interest for elucidating the control of normal cellular physiology as well as malignant transformation. The paradigm for activation of Akt involves phosphatidylinositol 3-kinase-dependent membrane localization followed by activating phosphorylation of Thr-308 and Ser-473. Many of the activating signals for Akt involve the stimulation of receptor and non-receptor tyrosine kinases, and the most potent activator known is the tyrosine phosphatase inhibitor pervanadate, highlighting a possible role for tyrosine phosphorylation in the regulation of the enzyme. In this study we show that activation of Akt by pervanadate or serum is associated with tyrosine phosphorylation of Akt. In addition, in SKOV3 ovarian carcinoma cells that exhibit high basal levels of Akt activity, Akt was tyrosine-phosphorylated in the basal state, and this phosphorylation was further enhanced by both pervanadate and insulin-like growth factor-1. We have used NH(2)-terminal sequencing and phosphate release analysis to directly identify Tyr-474 as the site of tyrosine phosphorylation. Substitution of Tyr-474 with phenylalanine abolished tyrosine phosphorylation of Akt and resulted in up to 55% inhibition of Akt activation, indicating phosphorylation at Tyr-474 is required for full activation of the kinase. Our data identifies a novel regulatory mechanism for this pleiotropic enzyme that may be applicable to the AGC family of protein kinases given the conserved nature of the COOH-terminal hydrophobic motif containing Tyr-474.

Mixed lineage kinase 2 interacts with clathrin and influences clathrin-coated vesicle trafficking.

Mixed lineage kinase 2 (MLK2) is a protein kinase that signals in the stress-activated Jun N-terminal kinase signal transduction pathway. We used immunoprecipitation and mass spectrometric analysis to identify MLK2-binding proteins in cell lines with inducible expression of green fluorescent protein-tagged MLK2. Here we report the identification of clathrin as a binding partner for MLK2 in both cultured cells and mammalian brain. We demonstrate that clathrin binding requires a motif (LLDMD) located near the MLK2 C terminus, which is similar to "clathrin box" motifs important for binding of clathrin coat assembly and accessory proteins to the clathrin heavy chain. A C-terminal fragment of MLK2 containing this motif binds strongly to clathrin, and mutation of the LLDMD sequence to LAAAD completely abrogates clathrin binding. We isolated clathrin-coated vesicles from green fluorescent protein-MLK2-expressing cells and from mouse brain lysates and found that MLK2 is enriched along with clathrin in these vesicles. In addition, we demonstrated that endogenous MLK2 co-immunoprecipitates with clathrin heavy chain from the vesicle-enriched fraction of mouse brain lysate. Furthermore, overexpression of MLK2 in cultured cells inhibits accumulation of labeled transferrin in recycling endosomes during receptor-mediated endocytosis. These findings suggest a role for MLK2 and the stress-signaling pathway at sites of clathrin activity in vesicle formation or trafficking.

Ro 31-6045, the inactive analogue of the protein kinase C inhibitor Ro 31-8220, blocks in vivo activation of p70(s6k)/p85(s6k): implications for the analysis of S6K signalling.

The mitogen-stimulated protein kinase p70(s6k)/p85(s6k) (S6K) plays an essential role in cell proliferation and growth, with inhibitors of the S6K signalling pathway showing promise as anti-tumour therapeutics. Here, we report that the bisindolylmaleimide derivative Ro 31-6045, previously reported to be inactive as a kinase inhibitor, inhibited S6K activity in vivo with an IC50=8 microM. Structure/function analysis using mutant forms of S6K indicates that Ro 31-6045 inhibition is independent of the upstream activator mTOR. Ro 31-6045 will prove useful in elucidating the complex activation mechanism of S6K and its independence from mTOR will allow confirmation of functional data obtained using the mTOR inhibitor rapamycin.

The synthetic peptide RPRAATF allows specific assay of Akt activity in cell lysates.

The Akt protein kinase is a critical signaling molecule in a range of cellular processes. A key to identifying the role of this pleiotropic kinase in any particular process is the ability to quantitate its activity. In this study we show that the synthetic peptide RPRAATF is a specific substrate for the kinase in crude cell extracts, thus enabling rapid, convenient, and sensitive assay of Akt activity. Peptide kinase activity was confined to a single peak upon sequential ion-exchange chromatography of whole-cell extracts of Balb/c 3T3 fibroblasts. This activity was stimulated by both platelet-derived growth factor and pervanadate, phosphatidyl inositol 3-kinase dependent, and inhibited by specific immunodepletion with anti-Akt antisera. Furthermore, direct assays of crude extracts from a range of cell types using this peptide were consistent with the results obtained using specific immunoprecipitation assays.