Proton and photon beams interaction with radiosensitizing agents in human glioblastoma cells

In oncological field, chemoradiotherapy treatments that combine radiations to radiosensitizing chemical agents are spreading out. The aim of this kind of treatment is to obtain a better tumor local control and at the same time to reduce the distant failure. The combination of radiation with microtubule-stabilizing agents is very promising in cancer therapy. In the present study, the combination of clinical proton beams and the microtubule-stabilizing agent Epothilone B has been investigated in human glioblastoma cells cultured in vitro. Photon beams have been used for comparison. Cell survival has been evaluated by colony forming assay and the interaction mechanism between radiation and Epothilone B has been investigated: survival curves relative to the combined treatment (protons or photons with Epothilone B) showed a linear trend, different from the linear quadratic behavior found with radiation alone. The analysis performed showed a synergism in the radiation-drug interaction. Thus, Epothilone B in conjunction with radiation acts as a radiosensitizer. Finally proton Relative Biological Effectiveness has been determined and results are reported in this paper

HADRON AND PHOTON IRRADIATION COMBINED WITH A CHEMOTHERAPY DRUG: AN IN VITRO STUDY IN HUMAN CANCER CELLS

Nowadays combined therapies exploiting chemotherapy agents and radiation used in conjunction attract a lot of interest, especially when dealing with radio-resistant tumors. In fact, it is known that some drugs have radio-sensitizing effects, for example inhibiting DNA repair mechanisms. The aim of these combined therapies is to obtain better tumor local control and to reduce the risk of distant failures. Many studies with different kind of chemical agents used in combination with photon beams have been performed for different cancers, but at the moment few data about the use of chemicals combined with hadrons are available. The purpose of the study described in this Thesis is the investigation of the interaction of charged hadrons (protons and Carbon ions) or photons and a the chemotherapy agent Epothilone B in human cancer cells cultured in vitro. In particular the study have been performed in lung adenocarcinoma (A549), glioblastoma multiforme (U251MG) and pediatric medulloblastoma (DAOY). Experiments with hadron and photon beams have been performed at the Centro Nazionale di Adroterapia Oncologica (CNAO) in Pavia and at the Istituto nazionale dei Tumori in Milano (IRCCS foundation), respectively. Different biological end-points have been evaluated in irradiated human cancer cells pre-treated or not with Epothilone B: clonogenic survival, cell growth and invasive capacity have been measured. Moreover, in order to evaluate the potential advantages of such a combined therapy, the interaction between radiation and drug has been analyzed to determine whether the interaction mechanism between the two cytotoxic agents is additive or synergic. Epothilone B resulted to act as a radiosensitizer especially with low-LET radiation (photons and protons). Moreover, hadron Relative Biological Effectiveness (RBE) was measured using photon beams as reference radiation, it resulted to be cell line dependent and results are reported in this Thesis

B- and C-type low molecular weight glutenin subunits in tetraploid wheat germplasm

General knowledge acquisition entails the extraction of statistical regularities from the environment. At high levels of complexity, this may involve the extraction, and consolidation, of associative regularities across event memories. The underlying neural mechanisms would likely involve a hippocampo-neocortical dialog, as proposed previously for system-level consolidation. To test these hypotheses, we assessed possible differences in consolidation between associative memories containing cross-episodic regularities and unique associative memories. Subjects learned face-location associations, half of which responded to complex regularities regarding the combination of facial features and locations, whereas the other half did not. Importantly, regularities could only be extracted over hippocampus-encoded, associative aspects of the items. Memory was assessed both immediately after encoding and 48 h later, under fMRI acquisition. Our results suggest that processes related to system-level reorganization occur preferentially for regular associations across episodes. Moreover, the build-up of general knowledge regarding regular associations appears to involve the coordinated activity of the hippocampus and mediofrontal regions. The putative cross-talk between these two regions might support a mechanism for regularity extraction. These findings suggest that the consolidation of cross-episodic regularities may be a key mechanism underlying general knowledge acquisition

Seed storage proteins of wild wheat progenitors and their relationships with technological properties

~A large collection of wild wheat progenitors, consisting of diploid (Triticum boeoticum Boiss. and Triticum urarlu Turn.) and tetraploid wheats (Triticum dicoccoides Korn.) was evaluated for certain grain quality parameters such as protein content and the SDS-Sedimentation test. The variation in protein content was larger in T. dicoccoides, ranging from 16 to 27 %, compared to diploid wheat (20-28 %). Some accessions appeared to be very promising for gluten properties, as measured by the SDS-test, when compared with some durum wheat cultivars. To determine the relationships between particular protein components and gluten properties, diploid, tetraploid wheats, and synthetic amphiploids (AABB x DD) were analysed by different electrophoretic procedures. Attention was focused on the study of the allelic variation at loci that in cultivated wheats play the major role in determining gluten quality (Glu-I, Gli-I and GIu-3). The range of allelic variation at the loci examined is remarkable, and genetic variants unique to wild wheats and positively related to gluten quality are reported

Effects of Cognitive Fatigue on High Intensity Circuit Exercise: Preliminary study

Please refer to the pdf version of the abstract located adjacent to the title

Combining proton or photon irradiation with epothilone B : An in vitro study of cytotoxicity in human cancer cells

Recently, the use of proton beams in cancer therapy is becoming widespread, and tumour treatment modalities combining radiosensitizing chemical agents with irradiation are under investigation in order to achieve greater tumour local control and reduce the probability of distant failures. The combined treatment modality of radiation and the clinically relevant microtubule-stabilizing compound epothilone B is a promising approach for anticancer therapy. In the present study, we investigated the cytotoxicity of a spread out Bragg peak (SOBP) proton beam, as well as of 6 MV photons, in human glioblastoma (U251 MG) and lung adenocarcinoma (A549) cells pretreated for 24 h, or not, with epothilone B at concentrations of 0.125 and 0.075 nM respectively. Proton irradiation was performed at the middle position of an actively modulated SOBP (12\u201318 cm depth in water) and cell survival was evaluated by a colony forming assay. For both cell lines, survival curves after proton or photon irradiation alone showed linear quadratic behaviour with proton RBE (relative biological effectiveness), compared with photons at 10% survival, of 1.5 \ub1 0.2. Treatment of cells with epothilone B at subnanomolar concentration has an anticlonogenic effect. Furthermore, differently from the results found with radiation alone, the survival curves for the combined treatment epothilone B\u2013radiation showed a linear trend and analysis of the interaction of the two cytotoxic agents indicated a slight synergism. These data provide a radiobiological basis for further experiments, as well as clinical studies

Increasing the amylose content of durum wheat through silencing of the SBEIIa genes

<p>Abstract</p> <p>Background</p> <p>High amylose starch has attracted particular interest because of its correlation with the amount of Resistant Starch (RS) in food. RS plays a role similar to fibre with beneficial effects for human health, providing protection from several diseases such as colon cancer, diabetes, obesity, osteoporosis and cardiovascular diseases. Amylose content can be modified by a targeted manipulation of the starch biosynthetic pathway. In particular, the inactivation of the enzymes involved in amylopectin synthesis can lead to the increase of amylose content. In this work, genes encoding starch branching enzymes of class II (SBEIIa) were silenced using the RNA interference (RNAi) technique in two cultivars of durum wheat, using two different methods of transformation (biolistic and Agrobacterium). Expression of RNAi transcripts was targeted to the seed endosperm using a tissue-specific promoter.</p> <p>Results</p> <p>Amylose content was markedly increased in the durum wheat transgenic lines exhibiting <it>SBEIIa </it>gene silencing. Moreover the starch granules in these lines were deformed, possessing an irregular and deflated shape and being smaller than those present in the untransformed controls. Two novel granule bound proteins, identified by SDS-PAGE in SBEIIa RNAi lines, were investigated by mass spectrometry and shown to have strong homologies to the waxy proteins. RVA analysis showed new pasting properties associated with high amylose lines in comparison with untransformed controls. Finally, pleiotropic effects on other starch genes were found by semi-quantitative and Real-Time reverse transcription-polymerase chain reaction (RT-PCR).</p> <p>Conclusion</p> <p>We have found that the silencing of <it>SBEIIa </it>genes in durum wheat causes obvious alterations in granule morphology and starch composition, leading to high amylose wheat. Results obtained with two different methods of transformation and in two durum wheat cultivars were comparable.</p

Expressed Ay HMW glutenin subunit in Australian wheat cultivars indicates a positive effect on wheat quality

Out of the six HMW-GS genes, 1Ay is usually not expressed in bread wheat cultivars. In the current study, an active 1Ay gene has been integrated into two Australian wheat cultivars, Livingston and Bonnie Rock, through conventional backcross approach. Three sister lines at BC4F4 generation for each cross were obtained and underwent a series of quality testing. Results show that the active 1Ay subunit increased the amount total protein, Glutenin/Gliadin ratio and unextractable polymeric protein. The expressed 1Ay also resulted in up to 10% increase of gluten content, 5% increase of glutenin, and hence increased the HMW- to LMW-GS ratio without affecting the relative amount of other subunits. Milling yield and Flour swelling were decreased in the Livingston lines and remained mostly unchanged for Bonnie Rock. Alveograph result showed that Ay improved dough strength in Livingston and dough extensibility in Bonnie Rock. Zeleny sedimentation value was found to be higher in all three lines of Bonnie Rock but only in one of Livingston derivatives. The dough development time and peak resistance, determined on the micro Z-arm mixer were increased in most cases. Overall, the integration of Ay subunit showed significant positive effects in bread making quality

Noodles made from high amylose wheat flour attenuate postprandial glycaemia in healthy adults

Previous research has not considered the effect of high amylose wheat noodles on postprandial glycaemia. The aim of the study is to investigate the effect of consumption of high amylose noodles on postprandial glycaemia over 2-h periods by monitoring changes in blood glucose concentration and calculating the total area under the blood glucose concentration curve. Twelve healthy young adults were recruited to a repeated measure randomised, single-blinded crossover trial to compare the effect of consuming noodles (180 g) containing 15%, 20% and 45% amylose on postprandial glycaemia. Fasting blood glucose concentrations were taken via finger-prick blood samples. Postprandial blood glucose concentrations were taken at 15, 30, 45, 60, 90 and 120 min. Subjects consuming high amylose noodles made with flour containing 45% amylose had significantly lower blood glucose concentration at 15, 30 and 45 min (5.5 ± 0.11, 6.1 ± 0.11 and 5.6 ± 0.11 mmol/L; p = 0.01) compared to subjects consuming low amylose noodles with 15% amylose (5.8 ± 0.12, 6.6 ± 0.12 and 5.9 ± 0.12 mmol/L). The total area under the blood glucose concentration curve after consumption of high amylose noodles with 45% amylose was 640.4 ± 9.49 mmol/L/min, 3.4% lower than consumption of low amylose noodles with 15% amylose (662.9 ± 9.49 mmol/L/min), p = 0.021. Noodles made from high amylose wheat flour attenuate postprandial glycaemia in healthy young adults, as characterised by the significantly lower blood glucose concentration and a 3.4% reduction in glycaemic response