MYC inhibition induces metabolic changes leading to accumulation of lipid droplets in tumor cells

The MYC genes are the most frequently activated oncogenes in human tumors and are hence attractive therapeutic targets. MYCN amplification leads to poor clinical outcome in childhood neuroblastoma, yet strategies to modulate the function of MYCN do not exist. Here we show that 10058-F4, a characterized c-MYC/Max inhibitor, also targets the MYCN/Max interaction, leading to cell cycle arrest, apoptosis, and neuronal differentiation in MYCN-amplified neuroblastoma cells and to increased survival of MYCN transgenic mice. We also report the discovery that inhibition of MYC is accompanied by accumulation of intracellular lipid droplets in tumor cells as a direct consequence of mitochondrial dysfunction. This study expands on the current knowledge of how MYC proteins control the metabolic reprogramming of cancer cells, especially highlighting lipid metabolism and the respiratory chain as important pathways involved in neuroblastoma pathogenesis. Together our data support direct MYC inhibition as a promising strategy for the treatment of MYC-driven tumors.     

A Case of Abnormal Lymphatic-Like Differentiation and Endothelial Progenitor Cell Activation in Neovascularization Associated with Hemi-Retinal Vein Occlusion

PurposePathological vascular differentiation in retinal vein occlusion (RVO)-related neovessel formation remains poorly characterized. The role of intraocular lymphatic-like differentiation or endothelial progenitor cell activity has not been studied in this disease.MethodsVitrectomy was performed in an eye with hemi-RVO; the neovessel membrane located at the optic nerve head was removed and subjected to immunohistochemistry. Characterization of the neovascular tissue was performed using hematoxylin and eosin, α-smooth muscle actin, and the pan-endothelial cell (EC) adhesion molecule CD31. The expression of lymphatic EC markers was studied by lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1), podoplanin (PDPN), and prospero-related homeobox protein 1 (Prox-1). Potential vascular stem/progenitor cells were identified by active cellular proliferation (Ki67) and expression of the stem cell marker CD117.ResultsThe specimen contained blood vessels lined by ECs and surrounded by pericytes. Immunoreactivity for LYVE-1 and Prox-1 was detected, with Prox-1 being more widely expressed in the active Ki67-positive lumen-lining cells. PDPN expression was instead found in the cells residing in the extravascular tissue. Expression of the stem cell markers CD117 and Ki67 suggested vascular endothelial progenitor cell activity.ConclusionsIntraocular lymphatic-like differentiation coupled with progenitor cell activation may be involved in the pathology of neovessel formation in ischemia-induced human hemi-RVO.Key Words: Hemi-retinal vein occlusion, Endothelial progenitor cell, Platelet endothelial cell adhesion molecule 1, Podoplanin, Prospero-related homeobox gene 1, Lymphatic endothelial cell, Lymphatic vessel endothelial hyaluronan receptor 1, Immunohistochemistry, Proliferative diabetic retinopathy, Vascular endothelial stem cell     

Daily Life Events Influence the Results of the Dexamethasone Suppression Test in Healthy Women

Although the Dexamethasone Suppression Test (DST) plays an important role in psychosomatic research, confounding factors limit the sensitivity and specificity of the DST. The aim of this study was to investigate the relationship between the intensity of daily life stressors and DST results in healthy participants after controlling the confounding factors. The subjects of this study consisted of 75 healthy volunteers. The intensity of daily life events was assessed using the Taiwanese version of the Recent Life Change Questionnaire (RLCQ). Neuroticism was assessed using the Maudsley Personality Inventory (MPI). The Dexamethasone Suppression Test (DST) was also performed. The regression model showed that daily life events (RLCQ score) were correlated significantly with cortisol level on day 1 and D% only in women. This finding implies that daily life events should be considered as an independent variable in women in further studies when the DST is applied.     

Parental Age and Risk of Autism Spectrum Disorders in a Finnish National Birth Cohort

Aim of the study was to examine the associations between parental age and autism spectrum disorders (ASD). Data were based on the FIPS-A (Finnish Prenatal Study of Autism and Autism Spectrum Disorders), a case-control study with a total of 4,713 cases with childhood autism (n = 1,132), Asperger’s syndrome (n = 1,785) or other pervasive developmental disorder (PDD) (n = 1,796), which were ascertained from the Finnish Hospital Discharge Register. Controls were selected from the Finnish Medical Birth Register. Conditional logistic regression models were used for statistical analyses. Advanced paternal age (35–49 years) was associated with childhood autism in offspring, whereas advanced maternal age was associated with both Asperger’s syndrome and PDD in offspring (35 years or more and 40 years or more, respectively). Teenage motherhood (19 years or less) was associated with PDD in offspring. The main finding was that maternal and paternal ages were differentially associated with ASD subtypes. In addition to advanced parental age, teenage pregnancy seems to incur a risk for PDD in offspring.     

Quantifying tumour hypoxia with fluorine-18 fluoroerythronitroimidazole ([<Superscript>18</Superscript>F]FETNIM) and PET using the tumour to plasma ratio

Fluorine-18 fluoroerythronitroimidazole ([(18)F]FETNIM) is a nitroimidazole compound that is potentially useful as a hypoxia marker in positron emission tomography (PET) studies of oncological patients. Our aim was to develop a simple protocol to quantitate uptake of [(18)F]FETNIM in hypoxic tumours. Dynamic imaging data from ten patients with head and neck cancer undergoing [(18)F]FETNIM PET was used in simulations and model fits to assess hypoxia marker uptake under different levels of blood flow. The distribution volume determined from dynamic PET study was compared with simple tumour to plasma and tumour to muscle ratios at 90-120 min. In skeletal muscle having a low but variable blood flow [2-6 ml/(100 gxmin)], differences in hypoxia-specific uptake of [(18)F]FETNIM remain small and may be hard to detect with PET. At higher blood flow [>20 ml/(100 gxmin)], the retention of [(18)F]FETNIM reflects the oxygenation status well and results in satisfactory contrast between hypoxic and well-oxygenated tissue. A good estimate of tissue hypoxia is accomplished by measuring the tissue to plasma [(18)F]FETNIM activity ratio using only a few late time points. The increased hypoxia-specific retention of [(18)F]FETNIM in tissues with high blood flow, such as malignant tumours, may facilitate application of [(18)F]FETNIM as a hypoxia marker in oncological patients. In the assessment of the tumour to non-target uptake ratio, plasma is the preferred reference tissue rather than muscle, which may show a more heterogeneous tracer uptake not easily controlled for.     

Nurse managers' conceptions of quality management as promoted by peer supervision

AIM: The aim of the study was to describe nurse managers' conceptions of quality management in their work as promoted by peer supervision. BACKGROUND: Quality management is one of the topical issues in a nurse manager's demanding and changing work. As first-line managers, they have a key role in quality management which is seen to create the system and environment for high quality services and quality improvement. Despite the official recommendations and definitions of quality management, several published reports have shown that there is no single solution for quality management. Peer supervision or the support provided by it to nursing managers have rarely been a subject of study. This study was carried out at Tampere University Hospital between 1996 and 1998. The peer supervision intervention was organized once a month, 2 hours at a time and in closed supervisor-led groups of nine nurse managers. METHODS: Data were collected by themed interviews. Fifteen nurse managers participated in the study. The data were analysed using the phenomenographic method. FINDINGS: Two main categories were formed of nurse managers' conceptions. The first described supportive and reflective characteristics of peer supervision. This main category was described by horizontal, hierarchical categories of support from peer group and reflection. The second main category described nurse managers' conceptions of individual development of leadership during peer supervision. This main category was also described by three horizontal categories: personal growth, finding psychological resources and internalization of leadership. CONCLUSION: The finding of this study show that peer supervision benefited nurse managers in quality management through reflection and support. The reflective and supportive characteristics of peer supervision promoted the nurse managers' individual development, but also that of leadership. It can be concluded that peer supervision promotes quality management in nurse managers' work.     

Valproic acid combined with 13-cis retinoic acid and 1,25-dihydroxyvitamin D3 in the treatment of patients with myelodysplastic syndromes

Valproic acid (VPA), an inhibitor of histone deacetylases, inhibits the growth of leukemia cells and induces their differentiation in vitro. In the present study, VPA in combination with two differentiating agents, 13-cis retinoic acid and 1,25-dihydroxyvitamin D3, was given to 19 previously untreated patients with MDS or CMML. Eight patients had to discontinue treatment before week 16 due to toxicity. According to international working group criteria, three patients (16%) responded to treatment. No correlation between VPA serum level, histone acetylation or clinical response was observed.