Agytumorok kezelése hipoxiás sejtekre célzottan ható génterápiás módszerekkel egér tumor modellen = Treatment of brain tumors by selective targeting of hypoxic, radioresistant tumor cells in a mouse tumor model

A projekt célja a sugárrezisztens és különösen a hipoxiás daganatsejtek sugárterápiával szembeni érzékenységének fokozása volt génterápiás módszerekkel. Két sugárérzékenyítő citosztatikum hatását kívántuk génterápiás módszerrel fokozni. Először a gemcitabin toxikus és sugárérzékenyítő hatását fokoztuk úgy, hogy a daganatsejtekben túltermeltettük a gemcitabin aktivációjáért felelős deoxicitidin kináz (dCK) enzimet egy dCK-t kódoló adenovírus vektornak a daganatsejtekbe való juttatásával. Kimutattuk, hogy a különböző glioma sejtvonalak alap dCK expressziója, illetve gemcitabin érzékenysége igen eltérő és a kettő között nem találtunk összefüggést. A fokozott dCK expresszió jelentős mértékben javította mind a gemcitabin toxikus, mind annak sugárérzékenyítő hatását in vitro és in vivo, de a hatás mértéke sejt-specifikus volt. A második rendszerben a tirapazamin (TPZ) hipoxiás sugárérzékenyítő szer hatását kívántuk fokozni úgy, hogy a TPZ aktivációjáért felelős NADPH-citokróm P450 reduktáz (N-CPR) enzim génjét termeltettük túl a daganatsejtekkel. A TPZ-nek csak mérsékelt citotoxikus és sugárérzékenyítő hatása volt normoxiás körülmények között, ami hipoxiában szignifikánsan megemelkedett. Az N-CPR fokozott expressziója tovább javította a TPZ-nek a hipoxia-specifikus toxicitását és sugárérzékenyítését, mind in vitro, mind in vivo. Eredményeinkkel igazoltuk, hogy a génterápiás módszerek alkalmazásával a kombinált daganatterápia célzottabbá és hatékonyabbá tehető. | The aim of the project was to increase the radisensitivity of radioresistant and hipoxic tumor cells by the means of gene therapy. We proposed to increase the effect of two radiosensitizing chemotherapeutic agents. First, we increased the toxic and radiosensitizing effect of gemcitabine by overexpressing the deoxicitidine kinase (dCK) enzyme, responsible for the intracellular activation of the drug. For this, a dCK-encoding adenoviral vector was constructed. There was a large variation both in the basal dCK level and gemcitabine sensitivity of various glioma cell lines, and no correlation could be shown between the two of them. However, dCK overexpression could improve both the toxic and radiosensitizing effect of gemcitabine in vitro and in vivo, but the effect was cell-type specific. Next, we constructed an adenoviral vector encoding for the gene of NADPH-cytochrome-P450 reductase (N-CPR), the enzyme responsible for the intracellular activation of the hypoxic cytotoxin, tirapazamine (TPZ). TPZ had only a mild toxic and radiosensitizing effect in normoxic conditions, which was significantly increased under hypoxic conditions. N-CPR overexpression further improved the hypoxia-specific toxicity and radiosensitization of TPZ both in vitro and in vivo. Thus, our work shows that the selectivity and efficiency of the combined antitumor therapy can be improved by the means of gene therapy

REM versus Non-REM sleep disturbance specifically affects inter-specific emotion processing in family dogs (Canis familiaris)

Abstract Dogs have outstanding capabilities to read human emotional expressions, both vocal and facial. It has also been shown that positively versus negatively valenced dog-human social interactions substantially affect dogs’ subsequent sleep. In the present study, we manipulated dogs’ (N = 15, in a within subject design) sleep structure by specifically disrupting REM versus Non-REM sleep, while maintaining equal sleep efficiency (monitored via non-invasive polysomnography). We found that both the number of awakenings as well as relative Non-REM (but not relative REM) duration influenced dogs’ viewing patterns in a task where sad and happy human faces were simultaneously projected with sad or happy human voice playbacks. In accordance with the emotion laterality hypothesis, the interaction between sound valence and Non-REM sleep duration was specific to images projected to the left (regardless of image-sound congruency). These results reveal the first evidence of a causal link between sleep structure and inter-specific emotion-processing in the family dog

Development of a non-invasive polysomnography technique for dogs (Canis familiaris)

Recently dogs (Canis familiaris) have been demonstrated to be a promising model species for studying human behavior as they have adapted to the human niche and developed human-like socio-cognitive skills. Research on dog behavior, however, has so far almost exclusively focused on awake functioning. Here we present a self-developed non-invasive easily replicable canine polysomnography method. N=22 adult pet dogs (with their owners present) and N=12 adult humans participated in Study I. From these subjects N=7 dogs returned on two more occasions for Study II. In Study I. we give a descriptive analysis of the sleep electroencephalogram of the dog and compare it to human data. In order to validate our canine polysomnography method in Study II. we compare the sleep macrostructure and the EEG spectrum of dogs after a behaviorally active versus passive day. In Study I. we found that dogsʼ sleep EEG resembled that of human subjects and was generally in accordance with previous literature using invasive technology. In Study II. we show that similarly to previous results on humans daytime load of novel experiences affects the macrostructural and spectral aspects of subsequent sleep. Our results validate the family dog as a model species for studying the effects of pre-sleep activities on the EEG pattern under natural conditions and thus broaden the perspectives of the rapidly growing fields of canine cognition and sleep research

Longitudinal Volumetric Assessment of Ventricular Enlargement in Pet Dogs Trained for Functional Magnetic Resonance Imaging (fMRI) Studies

Background: Recent studies suggest that clinically sound ventriculomegaly in dogs could be a preliminary form of the clinically significant hydrocephalus. We evaluated changes of ventricular volumes in awake functional magnetic resonance imaging (fMRI) trained dogs with indirectly assessed cognitive abilities over time (thus avoiding the use of anaesthetics, which can alter the pressure). Our research question was whether ventricular enlargement developing over time would have any detrimental effect on staying still while being scanned; which can be extrapolated to the ability to pay attention and to exert inhibition. Methods: Seven healthy dogs, 2–8 years old at the baseline scan and 4 years older at rescan, participated in a rigorous and gradual training for staying motionless (<2 mm) in the magnetic resonance (MR) scanner without any sedation during 6 minute-long structural MR sequences. On T1 structural images, volumetric analyses of the lateral ventricles were completed by software guided semi-automated tissue-type segmentations performed with FMRIB Software Library (FSL, Analysis Group, Oxford, UK). Results and conclusion: We report significant enlargement for both ventricles (left: 47.46 %, right: 46.07 %) over time while dogs retained high levels of attention and inhibition. The results suggest that even considerable ventricular enlargement arising during normal aging does not necessarily reflect observable pathological changes in behavior