Szilard Nemes

Elevated cyclin B2 expression in invasive breast carcinoma is associated with unfavorable clinical outcome

BackgroundBreast cancer is a potentially fatal malignancy in females despite the improvement in therapeutic techniques. The identification of novel molecular signatures is needed for earlier detection, monitoring effects of treatment, and predicting prognosis. We have previously used microarray analysis to identify differentially expressed genes in aggressive breast tumors. The purpose of the present study was to investigate the prognostic value of the candidate biomarkers CCNB2, ASPM, CDCA7, KIAA0101, and SLC27A2 in breast cancer.MethodsThe expression levels and subcellular localization of the CCNB2, ASPM, CDCA7, KIAA0101, and SLC27A2 proteins were measured using immunohistochemistry (IHC) on a panel of 80 primary invasive breast tumors. Furthermore, the mRNA levels of CCNB2, KIAA0101, and SLC27A2 were subsequently examined by qRT-PCR to validate IHC results. Patient disease-specific survival (DSS) was evaluated in correlation to protein levels using the Kaplan-Meier method. Multivariate Cox regression analysis was used to determine the impact of aberrant protein expression of the candidate biomarkers on patient DSS and to estimate the hazard ratio at 8-year follow-up.ResultsElevated cytoplasmic CCNB2 protein levels were strongly associated with short-term disease-specific survival of breast cancer patients (≤ 8 years; P<0.001) and with histological tumor type (P= 0.04). However, no association with other clinicopathological parameters was observed. Multivariate Cox regression analysis specified that CCNB2 protein expression is an independent prognostic marker of DSS in breast cancer. The predictive ability of several classical clinicopathological parameters was improved when used in conjunction with CCNB2 protein expression (C-index = 0.795) in comparison with a model without CCNB2 expression (C-index = 0.698). The protein levels of ASPM, CDCA7, KIAA0101, and SLC27A2 did not correlate with any clinicopathological parameter and had no influence on DSS. However, a significant correlation between the expression of the CCNB2 and ASPM proteins was detected (P = 0.03).ConclusionThese findings suggest that cytoplasmic CCNB2 may function as an oncogene and could serve as a potential biomarker of unfavorable prognosis over short-term follow-up in breast cancer.

Bias in odds ratios by logistic regression modelling and sample size

BackgroundIn epidemiological studies researchers use logistic regression as an analytical tool to study the association of a binary outcome to a set of possible exposures.MethodsUsing a simulation study we illustrate how the analytically derived bias of odds ratios modelling in logistic regression varies as a function of the sample size.ResultsLogistic regression overestimates odds ratios in studies with small to moderate samples size. The small sample size induced bias is a systematic one, bias away from null. Regression coefficient estimates shifts away from zero, odds ratios from one.ConclusionIf several small studies are pooled without consideration of the bias introduced by the inherent mathematical properties of the logistic regression model, researchers may be mislead to erroneous interpretation of the results.

Clinical Implications of Gene Dosage and Gene Expression Patterns in Diploid Breast Carcinoma

Purpose: Deregulation of key cellular pathways is fundamental for the survival and expansion of neoplastic cells. In cancer, regulation of gene transcription can be mediated in a variety of ways. The purpose of this study was to assess the impact of gene dosage on gene expression patterns and the effect of other mechanisms on transcriptional levels, and to associate these genomic changes with clinicopathologic parameters. Experimental Design: We screened 97 invasive diploid breast tumors for DNA copy number alterations and changes in transcriptional levels using array comparative genomic hybridization and expression microarrays, respectively. Results: The integrative analysis identified an increase in the overall number of genetic alterations during tumor progression and 15 specific genomic regions with aberrant DNA copy numbers in at least 25% of the patient population, i.e., 1q22, 1q22-q23.1, 1q25.3, 1q32.1, 1q32.1-q32.2, 8q21.2-q21.3, 8q22.3, 8q24.3, and 16p11.2 were recurrently gained, whereas 11q25, 16q21, 16q23.3, and 17p12 were frequently lost (P < 0.01). An examination of the expression patterns of genes mapping within the detected genetic aberrations identified 47 unique genes and 1 Unigene cluster significantly correlated between the DNA and relative mRNA levels. In addition, more malignant tumors with normal gene dosage levels displayed a recurrent overexpression of UBE2C, S100A8, and CBX2, and downregulation of LOC389033, STC2, DNALI1, SCUBE2, NME5, SUSD3, SERPINA11, AZGP1, and PIP. Conclusions: Taken together, our findings suggest that the dysregulated genes identified here are critical for breast cancer initiation and progression, and could be used as novel therapeutic targets for drug development to complement classical clinicopathologic features. Clin Cancer Res; 16(15); 3860–74. ©2010 AACR.

Projections of total hip replacement in Sweden from 2013 to 2030

Background and purpose — The continuously increasing demand for joint replacement surgery in the past decades imposes higher constraints on the budgets of hospitals and healthcare providers. We undertook an analysis of historical trends in total hip replacement performed in Sweden between 1968 and 2012 in order to provide projections of future demand. Data and methods — We obtained data on total hip replacements registered every year and on the evolution of the Swedish population between 1968 and 2012. We assumed the existence of a maximum incidence. So we adopted a regression framework that assumes the existence of an upper limit of total hip replacement incidence. Results — We found that the incidence of total hip replacement will continue to increase until a projected upper incidence level of about 400 total hip replacements per 105 Swedish residents aged 40 years and older will be reached around the year 2107. In 2020, the estimated incidence of total hip replacement will be 341 (95% prediction interval (PI): 302–375) and in 2030 it will be 358 (PI: 317–396). Using official forecasted population growth data, about 18,000 operations would be expected to be performed in 2020 and 20,000 would be expected to be performed in 2030. Interpretation — Growing incidence, population growth, and increasing life expectancy will probably result in increased demand for hip replacement surgery. Our findings could serve as a basis for decision making.

Additive effect of the AZGP1, PIP, S100A8 and UBE2C molecular biomarkers improves outcome prediction in breast carcinoma

The deregulation of key cellular pathways is fundamental for the survival and expansion of neoplastic cells, which in turn can have a detrimental effect on patient outcome. To develop effective individualized cancer therapies, we need to have a better understanding of which cellular pathways are perturbed in a genetically defined subgroup of patients. Here, we validate the prognostic value of a 13‐marker signature in independent gene expression microarray datasets (n = 1,141) and immunohistochemistry with full‐faced FFPE samples (n = 71). The predictive performance of individual markers and panels containing multiple markers was assessed using Cox regression analysis. In the external gene expression dataset, six of the 13 genes (AZGP1, NME5, S100A8, SCUBE2, STC2 and UBE2C) retained their prognostic potential and were significantly associated with disease‐free survival (p < 0.001). Protein analyses refined the signature to a four‐marker panel [AZGP1, Prolactin‐inducible protein (PIP), S100A8 and UBE2C] significantly correlated with cycling, high grade tumors and lower disease‐specific survival rates. AZGP1 and PIP were found in significantly lower levels in invasive breast tissue as compared with adjacent normal tissue, whereas elevated levels of S100A8 and UBE2C were observed. A predictive model containing the four‐marker panel in conjunction with established clinical variables outperformed a model containing the clinical variables alone. Our findings suggest that deregulated AZGP1, PIP, S100A8 and UBE2C are critical for the aggressive breast cancer phenotype, which may be useful as novel therapeutic targets for drug development to complement established clinical variables.

Up-regulation of cell cycle arrest protein BTG2 correlates with increased overall survival in breast cancer, as detected by immunohistochemistry using tissue microarray

BackgroundPrevious studies have shown that the ADIPOR1, ADORA1, BTG2 and CD46 genes differ significantly between long-term survivors of breast cancer and deceased patients, both in levels of gene expression and DNA copy numbers. The aim of this study was to characterize the expression of the corresponding proteins in breast carcinoma and to determine their correlation with clinical outcome.MethodsProtein expression was evaluated using immunohistochemistry in an independent breast cancer cohort of 144 samples represented on tissue microarrays. Fishers exact test was used to analyze the differences in protein expression between dead and alive patients. We used Cox-regression multivariate analysis to assess whether the new markers predict the survival status of the patients better than the currently used markers.ResultsBTG2 expression was demonstrated in a significantly lower proportion of samples from dead patients compared to alive patients, both in overall expression (P = 0.026) and cell membrane specific expression (P = 0.013), whereas neither ADIPOR1, ADORA1 nor CD46 showed differential expression in the two survival groups. Furthermore, a multivariate analysis showed that a model containing BTG2 expression in combination with HER2 and Ki67 expression along with patient age performed better than a model containing the currently used prognostic markers (tumour size, nodal status, HER2 expression, hormone receptor status, histological grade, and patient age). Interestingly, BTG2 has previously been described as a tumour suppressor gene involved in cell cycle arrest and p53 signalling.ConclusionsWe conclude that high-level BTG2 protein expression correlates with prolonged survival in patients with breast carcinoma.

Frequent MYC coamplification and DNA hypomethylation of multiple genes on 8q in 8p11-p12-amplified breast carcinomas.

Genetic and epigenetic (DNA methylation, histone modifications, microRNA expression) crosstalk promotes inactivation of tumor suppressor genes or activation of oncogenes by gene loss/hypermethylation or duplications/hypomethylation, respectively. The 8p11-p12 chromosomal region is a hotspot for genomic aberrations (chromosomal rearrangements, amplifications and deletions) in several cancer forms, including breast carcinoma where amplification has been associated with increased proliferation rates and reduced patient survival. Here, an integrative genomics screen (DNA copy number, transcriptional and DNA methylation profiling) performed in 229 primary invasive breast carcinomas identified substantial coamplification of the 8p11-p12 genomic region and the MYC oncogene (8q24.21), as well as aberrant methylation and transcriptional patterns for several genes spanning the 8q12.1-q24.22 genomic region (ENPP2, FABP5, IMPAD1, NDRG1, PLEKHF2, RRM2B, SQLE, TAF2, TATDN1, TRPS1, VPS13B). Taken together, our findings suggest that MYC activity and aberrant DNA methylation may also have a pivotal role in the aggressive tumor phenotype frequently observed in breast carcinomas harboring 8p11-p12 regional amplification.

Historical view and future demand for knee arthroplasty in Sweden

Background and purpose — The incidence of knee osteoarthritis will most likely increase. We analyzed historical trends in the incidence of knee arthroplasty in Sweden between 1975 and 2013, in order to be able to provide projections of future demand. Patients and methods — We obtained information on all knee arthroplasties in Sweden in the period 1975–2013 from the Swedish Knee Arthroplasty Register, and used public domain data from Statistics Sweden on the evolution of and forecasts for the Swedish population. We forecast the incidence, presuming the existence of a maximum incidence. Results — We found that the incidence of knee arthroplasty will continue to increase until a projected upper incidence level of about 469 total knee replacements per 105 Swedish residents aged 40 years and older is reached around the year 2130. In 2020, the estimated incidence of total knee arthroplasties per 105 Swedish residents aged 40 years and older will be 334 (95% prediction interval (PI): 281–374) and in 2030 it will be 382 (PI: 308–441). Using officially forecast population growth data, around 17,500 operations would be expected to be performed in 2020 and around 21,700 would be expected to be performed in 2030. Interpretation — Today’s levels of knee arthroplasty are well below the expected maximum incidence, and we expect a continued annual increase in the total number of knee arthroplasties performed.

Using connectivity metrics and niche modelling to explore the occurrence of the northern crested newt Triturus cristatus (Amphibia, Caudata) in a traditionally managed landscape

SUMMARY Spatial models are increasingly employed to help understand the distribution of organisms and establish conservation priorities. Classic patch- orientated models may have limited power to accurately predict the organismsdistributions. Pond breeding amphibians are appropriate study organisms because of their complex life cycle, low dispersal and sensitivity to environmental conditions. Here connectivity metrics and niche modelling were used to predict the occurrence of the northern crested newt in a rural landscape from central Romania. Pond-related variables, such as macrophyte cover and the presence of predatory fish, were the most important predictors of newt occurrence, followed by one landscape-related variable (urbanization) and a connectivity metric (nearest neighbouring occupied pond).Mostofthelandscapeandconnectivityvariables were not adequate predictors, presumably because most of the terrestrial habitats in this traditionally used rural landscape are ecologically optimal for amphibians. Conservation measures for the northern crested newt should promote the preservation of traditional extensive agricultural practices and discourage stocking of ponds with predatory fish.

BREEDING PHENOLOGY AND SPATIO-TEMPORAL DYNAMICS OF POND USE BY THE YELLOW-BELLIED TOAD (BOMBINA VARIEGATA) POPULATION: THE IMPORTANCE OF POND AVAILABILITY AND DURATION

We analysed the spatial and temporal variation of breeding habitat availability and use by a yellow-bellied toad population in a mixed deciduous forest between 2003n2005. During this period, the number of temporary ponds was highly variable. Toads tended to exploit newly created breeding habitats or those of which hydroperiod increased due to precipitation. Ponds with intermediate and long duration were preferred for reproduction. We found no evidence of predator avoidance behaviour (aquatic inver- tebrates and newts) or reproductive failure in ponds containing aquatic predators. Ponds located in sunny patches of the forest were preferred for reproduction. We suggest that ponds that act as sinks in years with low precipitation could contribute to the demography of toad populations in rainy years, when their hydroperiod increases.