Clear cell renal cell carcinoma (CC-RCC) is a highly vascularised tumour and is therefore an attractive disease to study angiogenesis and to test novel angiogenesis inhibitors in early clinical ...development. Endothelial cell proliferation plays a pivotal role in the process of angiogenesis. The aim of this study was to compare angiogenesis parameters in low nuclear grade (n=87) vs high nuclear grade CC-RCC (n=63). A panel of antibodies was used for immunohistochemistry: CD34/Ki-67, carbonic anhydrase IX, hypoxia-inducible factor-1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF). Vessel density (MVD - microvessel density), endothelial cell proliferation fraction (ECP%) and tumour cell proliferation fraction (TCP%) were assessed. mRNA expression levels of angiogenesis stimulators and inhibitors were determined by quantitative RT-PCR. High-grade CC-RCC showed a higher ECP% (P=0.049), a higher TCP% (P=0.009), a higher VEGF protein expression (P<0.001), a lower MVD (P< 0.001) and a lower HIF-1alpha protein expression (P=0.002) than low-grade CC-RCC. Growth factor mRNA expression analyses revealed a higher expression of angiopoietin 2 in low-grade CC-RCC. Microvessel density and ECP% were inversely correlated (Rho=-0.26, P=0.001). Because of the imperfect association of nuclear grade and ECP% or MVD, CC-RCC was also grouped based on low/high MVD and ECP%. This analysis revealed a higher expression of vessel maturation and stabilisation factors (placental growth factor, PDGFB1, angiopoietin 1) in CC-RCC with high MVD, a group of CC-RCC highly enriched in low nuclear grade CC-RCC, with low ECP%. Our results suggest heterogeneity in angiogenic activity and vessel maturation of CC-RCC, to a large extent linked to nuclear grade, and, with probable therapeutic implications.
This study examines N 2 O emission estimates from five different atmospheric inversion frameworks based on chemistry transport models (CTMs). The five frameworks differ in the choice of CTM, ...meteorological data, prior uncertainties and inversion method but use the same prior emissions and observation data set. The posterior modelled atmospheric N 2 O mole fractions are compared to observations to assess the performance of the inversions and to help diagnose problems in the modelled transport. Additionally, the mean emissions for 2006 to 2008 are compared in terms of the spatial distribution and seasonality. Overall, there is a good agreement among the inversions for the mean global total emission, which ranges from 16.1 to 18.7 TgN yr −1 and is consistent with previous estimates. Ocean emissions Published by Copernicus Publications on behalf of the European Geosciences Union. 6178 R. L. Thompson et al.: TransCom N 2 O model inter-comparison-Part 2 represent between 31 and 38 % of the global total compared to widely varying previous estimates of 24 to 38 %. Emissions from the northern mid-to high latitudes are likely to be more important, with a consistent shift in emissions from the tropics and subtropics to the mid-to high latitudes in the Northern Hemisphere; the emission ratio for 0-30 • N to 30-90 • N ranges from 1.5 to 1.9 compared with 2.9 to 3.0 in previous estimates. The largest discrepancies across inversions are seen for the regions of South and East Asia and for tropical and South America owing to the poor observational constraint for these areas and to considerable differences in the modelled transport, especially inter-hemispheric exchange rates and tropical convective mixing. Estimates of the seasonal cycle in N 2 O emissions are also sensitive to errors in modelled stratosphere-to-troposphere transport in the tropics and southern extratropics. Overall, the results show a convergence in the global and regional emissions compared to previous independent studies.
Vascular endothelial growth factor (VEGF)-A inhibitors exhibit unseen high responses and toxicity in recurrent epithelial ovarian cancer suggesting an important role for the VEGF/VEGFR pathway. We ...studied the correlation of VEGF signalling and AKT/mTOR signalling. Using a tissue microarray of clinical samples (N=86), tumour cell immunohistochemical staining of AKT/mTOR downstream targets, pS6 and p4E-BP1, together with tumour cell staining of VEGF-A and pVEGFR2 were semi-quantified. A correlation was found between the marker for VEGFR2 activation (pVEGFR2) and a downstream target of AKT/mTOR signalling (pS6) (R=0.29; P=0.002). Additional gene expression analysis in an independent cDNA microarray dataset (N=24) showed a negative correlation (R=-0.73, P<0.0001) between the RPS6 and the VEGFR2 gene, which is consistent as the gene expression and phosphorylation of S6 is inversely regulated. An activated tumour cell VEGFR2/AKT/mTOR pathway was associated with increased incidence of ascites (chi(2), P=0.002) and reduced overall survival of cisplatin-taxane-based patients with serous histology (N=32, log-rank test, P=0.04). These data propose that VEGF-A signalling acts on tumour cells as a stimulator of the AKT/mTOR pathway. Although VEGF-A inhibitors are classified as anti-angiogenic drugs, these data suggest that the working mechanism has an important additional modality of targeting the tumour cells directly.
Summary
Background Cyclooxygenase (COX)‐2 expression and tumour‐induced angiogenesis appear to be increased in squamous cell carcinoma (SCC) of the skin. In other cancers, COX‐2 is a pro‐angiogenic ...factor. The association between angiogenesis and COX‐2 has not been studied in skin cancer.
Objectives To assess the onset of increased COX‐2 expression and angiogenesis in the multistage carcinogenesis of SCC as well as the correlation between those two parameters.
Patients/methods We performed a retrospective paired immunohistochemical analysis of normal skin, actinic keratosis (AK), Bowen's disease (BD) and SCC among 35 individuals. Specimens were considered COX‐2 immunopositive when 5% or more of the tumour cells showed clear evidence of immunostaining. To quantify active angiogenesis, we used a Ki‐67–CD34 double‐labelling immunohistochemical stain and calculated the fraction of proliferating endothelial cells. The Chalkley method was used to determine the microvessel density. To detect hypoxia, a carboanhydrase IX immunostain was used.
Results Compared with normal epidermis (0%), AK (31%), BD (22%) and SCC (40%) were significantly more likely to be COX‐2 immunopositive (P < 0·01). The fraction of proliferating endothelial cells and the Chalkley scores paralleled multistage carcinogenesis (P < 0·05 between different stages). COX‐2 immunopositivity was fairly correlated with hypoxia and higher proliferating endothelial cell fractions but not with Chalkley counts.
Conclusions Induction of COX‐2 expression and angiogenesis are both early events in the development of SCC. In addition to ultraviolet light, hypoxia and COX‐2 may be involved in skin tumour angiogenesis.
Aberrant methylation of the adenomatous polyposis coli (APC) gene promoter occurs in about 40% of breast tumours and has been correlated with reduced APC protein levels. To what extent epigenetic ...alterations of the APC gene may differ according to specific breast cancer phenotypes, remains to be elucidated. Our aim was to explore the role of APC methylation in the inflammatory breast cancer (IBC) phenotype. The status of APC gene promoter hypermethylation was investigated in DNA from normal breast tissues, IBC and non-IBC by both conventional and real-time quantitative methylation-specific PCR (MSP). APC methylation levels were compared with APC mRNA and protein levels. Hypermethylation of the APC gene promoter was present in 71% of IBC samples (n=21) and 43% of non-IBC samples (n=30) by conventional MSP (P=0.047). The APC gene also showed an increased frequency of high methylation levels in IBC (in 74% of cases, n=19) vs non-IBC (in 46% of cases, n=35) using a qMSP assay (P=0.048). We observed no significant association between APC methylation levels by qMSP and APC mRNA or protein expression levels. In conclusion, for the first time, we report the association of aberrant methylation of the APC gene promoter with the IBC phenotype, which might be of biological and clinical importance.
Rheumatoid arthritis (RA) patients can be classified based on presence or absence of anticitrullinated peptide antibodies (ACPA) in their serum. This heterogeneity among patients may reflect ...important biological differences underlying the disease process. To date, the majority of genetic studies have focused on the ACPA-positive group. Therefore, our goal was to analyse the genetic risk factors that contribute to ACPA-negative RA.
We performed a large-scale genome-wide association study (GWAS) in three Caucasian European cohorts comprising 1148 ACPA-negative RA patients and 6008 controls. All patients were screened using the Illumina Human Cyto-12 chip, and controls were genotyped using different genome-wide platforms. Population-independent analyses were carried out by means of logistic regression. Meta-analysis with previously published data was performed as follow-up for selected signals (reaching a total of 1922 ACPA-negative RA patients and 7087 controls). Imputation of classical HLA alleles, amino acid residues and single nucleotide polymorphisms was undertaken.
The combined analysis of the studied cohorts resulted in identification of a peak of association in the HLA-region and several suggestive non-HLA associations. Meta-analysis with previous reports confirmed the association of the HLA region with this subset and an observed association in the CLYBL locus remained suggestive. The imputation and deep interrogation of the HLA region led to identification of a two amino acid model (HLA-B at position 9 and HLA-DRB1 at position 11) that accounted for the observed genome-wide associations in this region.
Our study shed light on the influence of the HLA region in ACPA-negative RA and identified a suggestive risk locus for this condition.
Epilepsy and mental retardation limited to females (EFMR), caused by
PCDH19
mutations, has a variable clinical expression that needs further exploration. Onset of epilepsy may be provoked by fever ...and can resemble Dravet syndrome. Furthermore, transmitting males have no seizures, but are reported to have rigid personalities suggesting possible autism spectrum disorders (ASD). Therefore, this study aimed to determine the phenotypic spectrum associated with
PCDH19
mutations in Dravet-like and EFMR female patients and in males with ASD. We screened 120 females suffering from Dravet-like epilepsy, 136 females with EFMR features and 20 males with ASD. Phenotypes and genotypes of the
PCDH19
mutation carriers were compared with those of 125 females with EFMR reported in the literature. We report 15 additional patients with a
PCDH19
mutation. Review of clinical data of all reported patients showed that the clinical picture of EFMR is heterogeneous, but epilepsy onset in infancy, fever sensitivity and occurrence of seizures in clusters are key features. Seizures remit in the majority of patients during teenage years. Intellectual disability and behavioural disturbances are common. Fifty percent of all mutations are missense mutations, located in the extracellular domains only. Truncating mutations have been identified in all protein domains. One ASD proband carried one missense mutation predicted to have a deleterious effect, suggesting that ASD in males can be associated with PCDH19 mutations.
Cancer cells can use existing blood vessels to acquire a vasculature. This process is termed ‘vessel co-option’. Vessel co-option is an alternative to the growth of new blood vessels, or ...angiogenesis, and is adopted by a wide range of human tumour types growing within numerous tissues. A complementary aspect of this process is extravascular migratory tumour spread using the co-opted blood vessels as a trail. Vessel co-opting tumours can be discriminated from angiogenic tumours by specific morphological features. These features give rise to distinct histopathological growth patterns that reflect the interaction of cancer cells with the microenvironment of the organ in which they thrive. We will discuss the histopathological growth patterns of vessel co-option in the brain, the liver and the lungs. The review will also highlight evidence for the potential clinical value of the histopathological growth patterns of cancer. Vessel co-option can affect patient outcomes and resistance to cancer treatment. Insight into the biological drivers of this process of tumour vascularization will yield novel therapeutic strategies.
PDF
