Serum nucleosomes during neoadjuvant chemotherapy in patients with cervical cancer. Predictive and prognostic significance

BACKGROUND: It has been shown that free DNA circulates in serum plasma of patients with cancer and that at least part is present in the form of oligo- and monucleosomes, a marker of cell death. Preliminary data has shown a good correlation between decrease of nucleosomes with response and prognosis. Here, we performed pre- and post-chemotherapy determinations of serum nucleosomes with an enzyme-linked immunosorbent assay (ELISA) method in a group of patients with cervical cancer receiving neoadjuvant chemotherapy. METHODS: From December 2000 to June 2001, 41 patients with cervical cancer staged as FIGO stages IB2-IIIB received three 21-day courses of carboplatin and paclitaxel, both administered at day 1; then, patients underwent radical hysterectomy. Nucleosomes were measured the day before (baseline), at day seven of the first course and day seven of the third course of chemotherapy. Values of nucleosomes were analyzed with regard to pathologic response and to time to progression-free and overall survival. RESULTS: All patients completed chemotherapy, were evaluable for pathologic response, and had nucleosome levels determined. At a mean follow-up of 23 months (range, 7–26 months), projected progression time and overall survival were 80.3 and 80.4%, respectively. Mean differential values of nucleosomes were lower in the third course as compared with the first course (p >0.001). The decrease in the third course correlated with pathologic response (p = 0.041). Survival analysis showed a statistically significant, better progression-free and survival time in patients who showed lower levels at the third course (p = 0.0243 and p = 0.0260, respectively). Cox regression analysis demonstrated that nucleosome increase in the third course increased risk of death to 6.86 (95% confidence interval [CI 95%], 0.84–56.0). CONCLUSION: Serum nucleosomes may have a predictive role for response and prognostic significance in patients with cervical cancer patients treated with neoadjuvant chemotherapy

IGF-I induced genes in stromal fibroblasts predict the clinical outcome of breast and lung cancer patients

<p>Abstract</p> <p>Background</p> <p>Insulin-like growth factor-1 (IGF-I) signalling is important for cancer initiation and progression. Given the emerging evidence for the role of the stroma in these processes, we aimed to characterize the effects of IGF-I on cancer cells and stromal cells separately.</p> <p>Methods</p> <p>We used an <it>ex vivo </it>culture model and measured gene expression changes after IGF-I stimulation with cDNA microarrays. <it>In vitro </it>data were correlated with <it>in vivo </it>findings by comparing the results with published expression datasets on human cancer biopsies.</p> <p>Results</p> <p>Upon stimulation with IGF-I, breast cancer cells and stromal fibroblasts show some common and other distinct response patterns. Among the up-regulated genes in the stromal fibroblasts we observed a significant enrichment in proliferation associated genes. The expression of the IGF-I induced genes was coherent and it provided a basis for the segregation of the patients into two groups. Patients with tumours with highly expressed IGF-I induced genes had a significantly lower survival rate than patients whose tumours showed lower levels of IGF-I induced gene expression (<it>P </it>= 0.029 - Norway/Stanford and <it>P </it>= 7.96e-09 - NKI dataset). Furthermore, based on an IGF-I induced gene expression signature derived from primary lung fibroblasts, a separation of prognostically different lung cancers was possible (<it>P </it>= 0.007 - Bhattacharjee and <it>P </it>= 0.008 - Garber dataset).</p> <p>Conclusion</p> <p>Expression patterns of genes induced by IGF-I in primary breast and lung fibroblasts accurately predict outcomes in breast and lung cancer patients. Furthermore, these IGF-I induced gene signatures derived from stromal fibroblasts might be promising predictors for the response to IGF-I targeted therapies.</p> <p>See the related commentary by Werner and Bruchim: <url>http://www.biomedcentral.com/1741-7015/8/2</url></p

Scientists' warning on climate change and insects

Climate warming is considered to be among the most serious of anthropogenic stresses to the environment, because it not only has direct effects on biodiversity, but it also exacerbates the harmful effects of other human-mediated threats. The associated consequences are potentially severe, particularly in terms of threats to species preservation, as well as in the preservation of an array of ecosystem services provided by biodiversity. Among the most affected groups of animals are insects—central components of many ecosystems—for which climate change has pervasive effects from individuals to communities. In this contribution to the scientists' warning series, we summarize the effect of the gradual global surface temperature increase on insects, in terms of physiology, behavior, phenology, distribution, and species interactions, as well as the effect of increased frequency and duration of extreme events such as hot and cold spells, fires, droughts, and floods on these parameters. We warn that, if no action is taken to better understand and reduce the action of climate change on insects, we will drastically reduce our ability to build a sustainable future based on healthy, functional ecosystems. We discuss perspectives on relevant ways to conserve insects in the face of climate change, and we offer several key recommendations on management approaches that can be adopted, on policies that should be pursued, and on the involvement of the general public in the protection effort

Discrimination of allied species within the genus Turbinaria (Fucales, Phaeophyceae) using HRMAS NMR spectroscopy

A novel chemotaxonomical method based on ID H-1 HRMAS NMR spectroscopy is being tested for taxonomical purposes. This powerful technique allowed us to discriminate between specimens belonging to two sister species of Turbinaria, which are difficult to tell apart using only morphological characters. Based on spectra analysis, the results allowed us to successfully group the specimens according to their species. Thus, the efficiency of HRMAS NMR spectroscopy for the discrimination of algal species and for the pre-screening of potential chemomarkers is demonstrated

Effect of a cover crop on the aphid incidence is not explained by increased top-down regulation

International audienceBACKGROUND: Cover crops can be used as a habitat management strategy to enhance the natural enemies and their temporal synchronization with a target pest. We examined the effect of winter oat intercropping within organic plum orchards on the natural enemy abundance and seasonal dynamics on the biological control of plum aphids in spring in Central Chile. METHODS: We compared the incidence and abundance of natural enemies and aphid pests from winter to the end of spring using two treatments: (1) plum trees with an oat cover crop (OCC) and (2) plum trees without a cover crop but with spontaneous vegetation (SV). We hypothesized that cover crops allow the development of winter cereal aphids, promoting the early arrival of natural enemies in spring, resulting in an earlier control of plum aphids. RESULTS: Winter cereal aphids developed well on the OCC, and as a result, a lower plum aphid incidence in spring was observed when compared to the SV. However, the abundance of natural enemies and the parasitism rates cannot explain the positive impacts of the oat cover crop on the aphid populations as there were no differences between treatments. A potential effect of the oat due to chemical and/or physical stimuli (bottom-up effects) could help to explain these results

Suitability and Profitability of a Cereal Aphid for the Parasitoid Aphidius platensis in the Context of Conservation Biological Control of Myzus persicae in Orchards

International audienceThe use of cover crops can promote the abundance and early arrival of populations of natural enemies. Cereal cover crops between orchards rows could encourage the early arrival of the parasitoid , as they offer alternative winter hosts (e.g., ), enhancing the control of in spring. However, the preference for and suitability of the alternative host must be addressed beforehand. To evaluate the potential of this strategy, we assessed host preference using behavioural choice tests, as well as no-choice tests measuring fitness traits, when developing on both host species. One source field for each aphid population from the above hosts was chosen. There was a clear choice for compared to , independently of the source, probably due to more defensive behaviours of (i.e., kicks and escapes). Nevertheless, both aphid species were suitable for parasitoids' development. The female progeny developed on were larger in size, irrespective of their origin. According to our results, in peach orchards with cereals sown between peach trees during the autumn, where we expect when populations will no longer be available during spring, should be able to switch to

Composition and Structure of Winter Aphid-Parasitoid Food Webs along a Latitudinal Gradient in Chile.

International audienceAll species interact in complex antagonistic or mutualistic networks that may be driven by turnover in species composition due to spatiotemporal environmental filtering. Therefore, studying differences in insect communities along environmental gradients may improve our understanding of the abiotic and biotic factors that shape the structure of trophic networks. Parasitoids are interesting models to do so, due to their intimate eco-evolutionary relationship with their hosts. We explored the differences in cereal aphid-parasitoid food webs during the winter among nine localities in Chilean central-south valley, along a gradient of 1200~km from north (29° S) to south (40° S). We hypothesized that diapause incidence would increase in the coldest areas, resulting in a lower number of parasitoid species active during the winter. Consequently, network specialization, generality, and vulnerability indexes should increase with decreasing latitude, which implies fewer and more weakly connected links per parasitoid species through an increased fraction of basal host species. Based on the severity of winter, three areas along the explored gradient were distinguished, but clustering did not follow a clear north-south latitudinal gradient. Instead, few differences were observed in overwintering strategies, with very low levels of diapause in all localities, and no major differences in food-web composition. The major differences along the gradient were the relative abundances of the different aphid, parasitoid and hyperparasitoid species, with higher levels of spatial and temporal variation observed for the less abundant species. Our results provide a better understanding of the activity and abundance of aphid parasitoids during winter in relation to climatic conditions

Total phenolic, size-fractionated phenolics and fucoxanthin content of tropical Sargassaceae (Fucales, Phaeophyceae) from the South Pacific Ocean : spatial and specific variability

This innovative study investigates 18 Turbinaria and Sargassum brown seaweed samples from three archipelagos of the South West Pacific Ocean. The phenolic content of crude and size-fractionated extracts was determined by the Folin-Ciocalteu method; fucoxanthin was measured using high performance liquid chromatography. Although the phenolic content proved to be low for the species of both genera tested, the levels in the species of Turbinaria were higher than those of Sargassum tested, except in the Fiji islands where both species produced similar contents. These investigations also highlighted variations of total phenolic content with spatial, reef morphology and depth. A large number of small phenolic compounds (< 2000 Da) were observed irrespective of the genus analyzed. Nevertheless, the composition of the phenolic pool varied in relation with the genus, the archipelago from which the material was collected, geomorphological features and the depth of each collection field site. A similar observation was for fucoxanthin content and in general, the measured constituents of the Turbinaria were less than those of the Sargassum species. The results are discussed in terms of inter- and intra-specific variability. Variations in both phenolic and fucoxanthin content were noted in tropical members of the Sargassaceae; such differences could be a result of specific chemical defense mechanisms adopted by members of each genus

Overwintering strategies and life-history traits of different populations of Aphidius platensis along a latitudinal gradient in Chile

International audienceThe onset of an overwintering strategy to overcome cold temperatures of a species of ectotherms can include remaining active or entering diapause. This in turn will depend on the relative costs of each strategy and therefore, could differ among populations along a latitudinal gradient. Thus, expecting higher levels of diapause in the coldest conditions and a higher incidence of individuals remaining active in the warmest conditions. We assessed the insect responses to photoperiod and temperature, in five Chilean populations of the aphid parasitoid Aphidius platensis. We analysed the variation in winter temperature along the latitudinal gradient and, under controlled conditions, examining the potential effects of three constant conditions of photoperiod/temperature: 8:16LD (Light: Dark, hours) at 10 degrees C, 10:14LD at 14 degrees C, and 16:8LD at 20 degrees C, on diapause levels. Finally, we measured cold tolerance (CTMin), developmental time, fresh body mass and size, fat and water content, and egg load for the emerging parasitoids. Our results showed no clear latitudinal gradient in temperature but differences among sites were clear. None of the five populations of A. platensis expressed diapause at any tested condition, suggesting that the environmental thresholds for diapause induction are perhaps not reached in this species under the studied latitudes. Insects from the coldest point in the gradient (Pinto) showed the lowest CTMin suggesting local adaptation. Moreover, physiological and life-history traits seem to adjust rapidly through developmental thermal acclimation, showing that plasticity is involved in the parasitoid's responses to the temperature differences found among localities. Consequently, both local adaptation and phenotypic plasticity contribute to this species remaining active during the whole winter, being an effective strategy to diapause in relatively mild and stable thermal environments