Association of Merkel cell polyomavirus infection with tumor p53, KIT, stem cell factor, PDGFR-alpha and survival in Merkel cell carcinoma

Most Merkel cell carcinomas (MCCs) contain Merkel cell polyomavirus (MCPyV) DNA, and the virus likely has a pivotal role in tumor pathogenesis. p53 and the KIT receptor tyrosine kinase have also been implicated in MCC pathogenesis, but little is known about their association with MCPyV infection. We identified 207 patients diagnosed with MCC in Finland in 1979-2004 and reviewed the histological diagnoses. Adequate clinical information, tumor tissue and DNA were available from 87 confirmed MCC cases. Presence of MCPyV DNA was assessed using quantitative PCR; p53, KIT, phospho-KIT, stem cell factor (SCF) and PDGFRα expression using immunohistochemistry and presence of mutations in KIT exons 9, 11, 13 and 17 and PDGFRA exons 10, 12, 14 and 18 using DNA sequencing. Most (77.0%) of the 87 tumors contained MCPyV DNA and 37 (42.5%) expressed KIT, whereas PDGFRα, p53, SCF and pKIT expression was less common (31.9, 22.8, 8.6 and 4.8%, respectively). No KIT or PFGFRA mutations were detected, but 10 (12.5%) of the 80 tumors studied harbored common PDGFRA exon 10 S478P substitution. Tumor p53 and KIT expression were associated with absence of MCPyV DNA (p = 0.01 and 0.009, respectively). Tumor p53 expression was associated with unfavorable MCC-specific survival (p = 0.021) and overall survival (p = 0.046), but tumor KIT expression only when stratified by presence of MCPyV DNA. The results suggest that p53 and KIT expression are associated with absence of MCPyV DNA in MCC, and that the molecular pathogenesis of MCC is multifactorial.     

A probiotic mixture including galactooligosaccharides decreases fecal β-glucosidase activity but does not affect serum enterolactone concentration in men during a two-week intervention

A high serum concentration of enterolactone, an enterolignan produced by colonic microbiota from precursors in cereals, vegetables, and fruits, is associated with reduced risk of acute coronary events. Probiotics and prebiotics modify colonic metabolism and may affect the serum enterolactone concentration. The effects of a probiotic mixture alone and with galactooligosaccharides (GOS) on serum enterolactone concentration and fecal metabolism were investigated in 18 healthy men. Participants received 3 interventions, each for 2 wk: 1) probiotics [Lactobacillus rhamnosus strains GG (LGG) and LC705, Propionibacterium freudenreichii ssp. shermanii JS, and Bifidobacterium breve Bb99, for a total amount of 2 × 10(10) CFU/d]; 2) probiotics and GOS 3.8 g/d; 3) probiotics, GOS, and rye bread (minimum 120 g/d). Serum enterolactone and fecal dry weight, enzyme activities, pH, SCFA, lactic acid bacteria, bifidobacteria, propionibacteria, and the strains LGG and LC705 were determined. The serum enterolactone concentration (nmol/L) tended to be decreased from baseline [mean (95% CI) 18.6 (10.8-26.4)] by probiotics alone [15.2 (7.8-22.7); P = 0.095], was not significantly affected by probiotics with GOS [21.5 (13.2-29.8)], and was increased by probiotics with GOS and rye bread [24.6 (15.4-33.7); P < 0.05]. Probiotics alone did not affect fecal β-glucosidase activity and bifidobacteria, but probiotics with GOS decreased β-glucosidase activity and increased bifidobacteria compared with baseline (P < 0.05) and with probiotics alone (P < 0.01). In conclusion, this probiotic mixture with or without GOS does not significantly affect serum enterolactone concentration. Because probiotics with GOS decreased fecal β-glucosidase activity but not serum enterolactone, the reduced fecal β-glucosidase, within the range of activities measured, does not seem to limit the formation of enterolactone.     

Recurrent DNA copy number changes revealed by comparative genomic hybridization in primary Merkel cell carcinomas.

Comparative genomic hybridization (CGH) was used to search for gains, high-level amplifications and losses of DNA sequences along all chromosome arms in 19 primary Merkel cell carcinomas (MCC). Extensive genetic aberrations, with a mean value of 5.5+/-1.1 changes per tumor were detected in 13 out of the 19 samples analyzed. Our CGH results reveal several new and other previously known chromosomal regions that are involved in the pathogenesis of MCC. The majority of the alterations were gains of whole chromosomes or whole chromosome arms. Compared to losses, the frequency of DNA copy number gains was two-fold. DNA sequence copy number gains were most common in chromosomes 6 (42%), 1 (37%), and 5 (32%). The most frequent minimal common regions of gains were 6pterqter (42%), 1q11q31 (32%), and 5p (32%). No recurrent high-level amplifications were observed. High-level amplifications of small chromosomal regions were found in four samples out of the 19 tumors analyzed (21%). Amplifications affected 1q22q24 (5%), 4p (5%), and 5p (5%). Losses most frequently affected chromosomes 13 (21%) and 4 (16%). Minimal common regions with the most frequent losses were 13q13q31 (21%), 4q (16%), and 16q (11%). No significant statistical correlation between genomic aberrations and clinicopathological factors was revealed, despite the fact that there was an obvious tendency towards it. Primary MCC expressing DNA alterations were predominantly distinguished in large tumors, and risk of metastatic dissemination was three-fold compared to tumors with no DNA alterations.     

Mesh-based method for measuring intracranial volume in patients with craniosynostosis

Purpose

   Craniosynostosis may lead to reduced intracranial volume (ICV) and disturb normal brain growth and development. Thus, ICV is an important parameter with respect to the surgical outcome. Current methods for ICV determination from computed tomography (CT) images have drawbacks. The aim of this study was to investigate the performance of the novel mesh-based method (MBM) for ICV determination with craniosynostosis patients.

Methods

   Twenty-two patients operated on for scaphocephaly were included in this study. ICVs from preoperative, one-week postoperative, and one-year postoperative CT images were measured with MBM. The level of agreement with the manual segmentation method (MSM) was determined for the measurements of preoperative and one-year postoperative datasets. Repeatability was determined with re-measurements of six datasets. Measurement time was recorded for MBM.

Results

   Mean $(\pm \text{ SD})$ preoperative ICV values were 895.0 $\pm $ 153.1 $\text{ cm}^{3}$ and 896.4 $\pm $ 147.2 $\text{ cm}^{3}$ as measured with MBM and MSM, respectively. Corresponding one-year postoperative values were 1,238.3 $\pm $ 118.7 $\text{ cm}^{3}$ and 1,250.1 $\pm $ 117.5 $\text{ cm}^{3}$ . The MBM allowed ICV determination from one-week postoperative datasets. Measurement time with MBM was 4

Conclusions

   MBM is an efficient method for determining the ICV of craniosynostosis patients, allowing the measurement of skulls with bony defects. The repeatability and short measurement time of MBM are attributable to the user interference and assessment of the measurement process.     

FK506 blocks activation of the intrinsic caspase cascade after optic nerve crush

Retinal ganglion cells die by apoptosis after optic nerve crush. FK506 has been shown to be neuroprotective in this model but the mechanism(s) by which it exerts these actions remains unknown. We and others have shown that caspase 9 is cleaved in the retina in other injury models and we hypothesized that the neuroprotection observed with FK506 was mediated by interference with caspase 9 activation. The present study examined the cellular localization of caspase 9 cleavage after intraorbital optic nerve crush in rats, the time course of caspase 9 cleavage after optic nerve crush and the ability of orally administered FK506 to block caspase 9 cleavage after optic nerve crush. We show by immunohistochemistry that cleaved caspase 9 is present in retinal ganglion cells (identified by prior backlabelling) after optic nerve crush. Immunoblot analysis showed that caspase 9 cleavage is significantly elevated 5 and 8 days after optic nerve crush. We show that orally administered FK506 reaches the retina and is pharmacologically active in retinal tissue. Furthermore, the oral administration of FK506 5 mg kg(-1) day(-1) blocks the cleavage of caspase 9 at both time points. These data suggest that caspase 9 activation may play an important role in retinal ganglion cell death following optic nerve crush and that the neuroprotection seen with FK506 may be mediated by interfering with the activation of caspase 9.     

Bcl-2 expression indicates better prognosis of Merkel cell carcinoma regardless of the presence of Merkel cell polyomavirus

Merkel cell carcinoma (MCC) is an aggressive dermal tumour of neuroendocrine origin. The recently found Merkel cell polyomavirus (MCV) integrates clonally in the tumour genome, which suggests an important role in the pathogenesis of the disease. Previous small-scale studies have detected anti-apoptotic protein bcl-2 in 80?% of MCC tumours, but its correlation to the prognosis of MCC remains controversial. Our aim was to clarify the correlation of immunohistochemical expression of bcl-2 to MCV presence and MCC prognosis. We analyzed 116 primary MCC specimens with corresponding clinical data by immunohistochemistry for bcl-2. The presence of MCV DNA had been analyzed by quantitative PCR for 108 tumours. The correlations were analyzed statistically. Of the primary MCC samples, 85?% were bcl-2 positive. No significant differences in MCV DNA occurred between the bcl-2-positive and bcl-2-negative tumours. Local and systemic metastasis was more common in patients with bcl-2 negative tumours (33?%) than in patients with bcl-2-positive tumours (12?%; p?=?0.04) at the time of diagnosis. The mean overall survival was higher in patients with bcl-2-positive tumours than of those with negative tumours (mean survival 1,814?days (5.0?years) vs. 769?days (2.1?years), p?=?0.01). Bcl-2 positivity indicates better clinical stage at the time of diagnosis and a longer survival in MCC.     

Evaluation of Ki-67 as a histological index of burn damage in a swine model

Histological diagnosis of burn depth lacks consensus. The purpose of this study was to determine whether Ki-67, a cell proliferation marker, provides an index of integument viability after burn injury. Induction of thermal burn injuries (3, 12, 20, 30, 75, 90, and 120 seconds) were made with a brass rod heated to 100°C on the dorsal trunk of the swine. Controls were created with a brass rod heated to 37.5°C. Four 6-mm biopsies were obtained from each site for histological analysis of Ki-67. Biopsies were taken at the following times postinjury: 1, 12, 24, 36, 48, 72, and 96 hours. The results illustrate a characteristic Ki-67 nuclear staining in the basal layer of the epidermis and in the hair follicle. With increasing thermal injury, the nuclei of the cells changed morphology: condensing, fragmenting, and elongating. The uniqueness of the labeling index was to include only morphologically intact nuclei as having capacity to proliferation. Quantitative analysis showed a reduction in the mean number of Ki-67-positive cells, suggesting a reduced regenerative capacity. This study supports using this index as a means of performing histology for burn depth analysis. In future studies, determining viability of partial-thickness burns will require multiple histological markers such as Ki-67 in addition to hematoxylin and eosin staining.     

Insulin Receptor β-Subunit Haploinsufficiency Impairs Hippocampal Late-Phase LTP and Recognition Memory

The insulin receptor (IR) is a protein tyrosine kinase playing a pivotal role in the regulation of peripheral glucose metabolism and energy homoeostasis. IRs are also abundantly distributed in the cerebral cortex and hippocampus, where they regulate synaptic activity required for learning and memory. As the major anabolic hormone in mammals, insulin stimulates protein synthesis partially through the activation of the PI3K/Akt/mTOR pathway, playing fundamental roles in neuronal development, synaptic plasticity and memory. Here, by means of a multidisciplinary approach, we report that long-term synaptic plasticity and recognition memory are impaired in IR ??-subunit heterozygous mice. Since IR expression is diminished in type-2 diabetes as well as in Alzheimer??s disease (AD) patients, these data may provide a mechanistic link between insulin resistance, impaired synaptic transmission and cognitive decline in humans with metabolic disorders.