Development of antitumor strategy by inhibition of thioredoxin reductase 1 in cell models of glioblastoma and neuroblastoma

Tioredoksinski sistem, ćelijski redoks regulator, ima važnu ulogu u nastanku tumora, progresiji, metastazi i sticanju rezistencije na lekove. Povišena ekspresija tioredoksin-reduktaze 1 (TrxR1) je u korelaciji sa stepenom maligniteta glioblastoma i neuroblastoma. Cilj ove disertacije bio je ispitivanje potencijala Ugi-tipa Majklovih akceptora (UMA) – inhibitora TrxR1 za lečenje glioblastoma i neuroblastoma, kao i u prevazilaženju višestruke rezistencije na hemioterapeutike. Shodno tome, ispitana je efikasnost UMA u inhibiciji TrxR1; zatim, dejstvo UMA inhibitora na rast ćelija neuroblastoma, glioblastoma i normalnih ćelija. Pokazano je da UMA inhibitori snažnije inhibiraju rast proliferišućih ćelija (neuroblastoma, glioblastoma i keratinocita) u odnosu na neproliferišuće mononuklearne ćelije krvi. Mehanizam antitumorskog dejstva dva najpotentnija inhibitora, DVD-444 i DVD-445, je ispitan na senzitivnim i rezistentnim ćelijama glioma. UMA inhibitori su prouzrokovali oksidativni stres, depolarizaciju mitohondrija i povišenu ekspresiju antioksidativnih enzima u ćelijama glioma. Utvrđeno je da imaju citotoksično, antiproliferativno i antiinvazivno dejstvo na ćelije glioma, kao i da povećavaju njihovu osetljivost na temozolomid. UMA inhibitori su suprimirali aktivnost P-glikoproteina (P-gp) i povećali osetljivost rezistentnih ćelija glioma na paklitaksel. Okarakterisani su antitumorski efekti serije inhibitora TrxR1 analognih DVD-445. Analozi DVD-445, su indukovali oksidativni stres, ćelijsku smrt i inhibirali aktivnost P-gp u ćelijama glioma u većoj meri od DVD-445. Rezultati ove disertacije ukazuju da je inhibicija TrxR1 perpsektivna strategija za lečenje glioblastoma i neuroblastoma, i da su UMA inhibitori TrxR1 dobri kandidati za razvoj novih hemioterapeutika.Thioredoxin system, cell redox regulator, has important role in tumor development, progression, metastasis and chemoresistance. Thioredoxin reductase 1 (TrxR1) high expression is in correlation with glioblastoma and neuroblastoma malignancy. Goal of this dissertation was investigating potential of Ugy-type Michael acceptors (UMAs) – TrxR1 inhibitors, for glioblastoma and neuroblastoma treatment, as well as in overcoming multidrug resistance. Accordingly, potential of TrxR1 inhibition by UMA was tested in vitro, followed by testing of UMA inhibitors on cell growth of neuroblastoma, glioblastoma and normal cells. UMA inhibitors demonstrated a stronger inhibitory effect on proliferating cells (neuroblastoma, glioblastoma, keratinocytes) in comparison to non-proliferating blood mononuclear cells. Antitumor effect mechanism of two most potent compounds, DVD-444 and DVD-445, was tested in sensitive and resistant glioma cells. UMA inhibitors caused oxidative stress, mitochondrial depolarisation and elevated expression of antioxidant enzymes in glioma cells, showed cytotoxic, antiproliferative and anti-invasive effect, and sensitized glioma cells to temozolomide. UMA inhibitors suppressed P-glycoprotein (P-gp) activity and sensitized resistant glioma cells to paclitaxel. Antitumor effects of DVD-445 analogue compounds were investigated. DVD-445 analogues induced oxidative stress, cell death and inhibited P-gp activity in glioma cells, at greater extent than DVD-445. Results presented here suggest that TrxR1 inhibition is a promising strategy in treating glioblastoma and neuroblastoma and that UMA inhibitors are aspiring candidates for novel chemotherapy development

The most frequent contact allergens in patients with contact dermatitis in the Slavonski Brod region

Cilj je ovog rada bio prikazati rezultate epikutanog testa standardnom serijom alergena na Odjelu za kožne i spolne bolesti Opće bolnice "Dr. Josip Benčević" u Slavonskom Brodu tijekom protekle dvije godine te ih usporediti s rezultatima testiranja u Alergološkoj ambulanti Klinike za kožne i spolne bolesti u Zagrebu i rezultatima testiranja brojnih inozemnih autora. Rezultati epikutanog mjesta standardnom serijom od 20 alergena uspoređivani su između Klinike za kožne i spolne bolesti, te Opće bolnice "Dr. Josip Benčević". Kroz 24 mjeseca ispitanici alergološke ambulante Odjela za kožne i spolne bolesti u Slavonskom Brodu testirani su standardnom serijom. Na Klinici za kožne i spolne bolesti na istu seriju alergena testirani su bolesnici u petogodišnjem periodu. Od naših bolesnika 172 su imala pozitivne reakcije, od toga 88 jednu pozitivnu reakciju, 60 dvije pozitivne reakcije, te 24 tri i/ili više pozitivnih reakcija. Najčešće pozitivne reakcije imali smo na nikal sulfat, kao što je vidljivo i u rezultatima Alergološke ambulante Klinike za kožne i spolne bolesti. Statistički značajne pozitivne reakcije zabilježene su kod tri alergena: nikal sulfat, kobalt klorid i smjesa mirisa. U našem dvogodišnjem praćenju učestalost pozitivnih epikutanih testova na nikal sulfat, formaldehid, Quarternium 15, te timerosal je podjednaka, dok je kod smjese mirisa, neomycin sulfata, kobalt klorida i peruanskog balzama nešto niža.The goal of this paper is to show the results of the epicutaneous (patch) test with standard allergens at the Department of Dermatology and Venerology of General Hospital "Dr. Josip Benčević" in Slavonski Brod in the past two years. The goal is also to compare these results with the results from the Allergological Infirmary in the Department of Dermatology and Venerology in Zagreb University Hospital Center. The results of patch testing with 20 standard allergens from General Hospital "Dr. Josip Benčević" and from the Department of Dermatology and Venerology in Zagreb University Hospital Center have been compared. In our "Dr, Josip Benčević" Hospital patients were tested during 2004 and 2005. In the Department of Dermatology and venerology in Zagreb University Hospital Center patients were tested in a five-year period. There were 172 patients with positive test results, out of which 88 had one positive reaction, 60 had two positive reactions, and 24 had three or more positive reactions. NiSO4 (or Nickel-sulfate) was the most common cause for the positive test reaction. The same compound was also the most common cause in the Department of Dermatology and Venerology in Zagreb University Hospital Center. Statistically significant positive reactions were present in three allergens: nickel sulfate, cobalt chloride and fragrance mix. In the two-year follow up (monitoring) frequency of epicutaneous (patch) test positive reactions on nickel sulfate, formaldehyde, Quarterinum-15 and Thimerosal is almost the same, while the frequency of positive reactions on fragrance mix, neomycin sulfate, cobalt chloride and balsam of Peru is somewhat lower

Decreased TSPAN14 Expression Contributes to NSCLC Progression

Tspan14 is a transmembrane protein of the tetraspanin (Tspan) protein family. Different members of the Tspan family can promote or suppress tumor progression. The exact role of Tspan14 in tumor cells is unknown. Earlier, mutational inactivation of the TSPAN14 gene has been proposed to coincide with a low survival rate in NSCLC patients. This study aimed to investigate the correlation of TSPAN14 lack of function with clinicopathological features of NSCLC patients, and to elucidate the role TSPAN14 might have in NSCLC progression. TSPAN14 expression was lower in tumor cells than non-tumor cells in NSCLC patients' samples. The decreased gene expression was correlated with a low survival rate of patients and was more frequent in patients with aggressive, invasive tumor types. Additionally, the role of decreased TSPAN14 expression in the metastatic potential of cancer cells was confirmed in NSCLC cell lines. The highly invasive NSCLC cell line (NCI-H661) had the lowest TSPAN14 gene and protein expression, whereas the NSCLC cell line with the highest TSPAN14 expression (NCI-H460) had no significant metastatic potential. Finally, silencing of TSPAN14 in these non-metastatic cancer cells caused an increased expression of matrix-degrading enzymes MMP-2 and MMP-9, followed by an elevated capacity of cancer cells to degrade gelatin. The results of this study propose TSPAN14 expression as an indicator of NSCLC metastatic potential and progression

Инхибиција аутофагије сензитизује ћелије глиобластома на инхибиторе Срц тирозин-киназе, деривате пиразоло[3,4- д]пиримидина Si306 и pro-Si306

Glioblastom je jedan od najagresivnijih tumora mozga koji karakteriše infiltrirajuća priroda, intenzivna proliferacija i rezistencija na terapiju. Ćelije glioblastoma imaju visoku ekspresiju Src tirozin-kinaze koja reguliše proliferaciju, preživljavanje i invazivnost tumorskih ćelija čineći je potencijalnom metom za terapiju. Inhibitori tirozin-kinaza mogu indukovati autofagiju koja deluje protektivno na tumorske ćelije. Sposobnost inhibitora Src tirozin-kinaze, derivata pirazolo[3,4-d]pirimidina Si306 i njegovog proleka pro-Si306, da indukuju autofagiju ispitana je na ćelijskoj liniji humanog glioblastoma U87 i njenoj varijanti sa višestrukom rezistencijom na lekove U87-TxR. Tretman ovim jedinjenjima uzrokovao je pojavu autofagozoma u ćelijama nakon 3 sata, a efekat na indukciju autofagije opstao je i nakon 48 sati što je utvrđeno analizom markera autofagije LC3 i p62. Inhibicija autofagnog fluksa bafilomicinom A1 značajno je uvećala postojeće anti-proliferativno dejstvo Si306 i pro-Si306. Takođe, kombinovani tretmani Src inhibitora sa bafilomicinom A1 doveli su do nekroze nakon 48 sati. Dobijeni rezultati sugerišu da autofagija indukovana ovim jedinjenjima ima zaštitnu ulogu u ćelijama glioblastoma i da se modulacija autofagije može koristiti za senzitizaciju ćelija glioblastoma na inhibitore Src tirozin-kinaze. Pored toga, pomenuti efekti Si306 i pro-Si306 nisu umanjeni prisustvom višestruko- rezistentnog fenotipa, što ovim jedinjenjima daje potencijal za lečenje rezistentnih tumora.Глиобластом је један од најагресивнијих тумора мозга који карактерише инфилтрирајућа природа, интензивна пролиферација и резистенција на терапију. Ћелије глиобластома имају високу експресију Срц тирозин-киназе која регулише пролиферацију, преживљавање и инвазивност туморских ћелија чинећи је потенцијалном метом за терапију. Инхибитори тирозин-киназа могу индуковати аутофагију која делује протективно на туморске ћелије. Способност инхибитора Срц тирозин-киназе, деривата пиразоло[3,4-д]пиримидина Si306 и његовог пролека pro-Si306, да индукују аутофагију испитана је на ћелијској линији хуманог глиобластома U87 и њеној варијанти са вишеструком резистенцијом на лекове U87-TxR. Третман овим једињењима узроковао је појаву аутофагозома у ћелијама након 3 сата, а ефекат на индукцију аутофагије опстао је и након 48 сати што је утврђено анализом маркера аутофагије LC3 и p62. Инхибиција аутофагног флукса бафиломицином А1 значајно је увећала постојеће анти-пролиферативно дејство Si306 и pro-Si306. Такође, комбиновани третмани Срц инхибитора са бафиломицином А1 довели су до некрозе након 48 сати. Добијени резултати сугеришу да аутофагија индукована овим једињењима има заштитну улогу у ћелијама глиобластома и да се модулација аутофагије може користити за сензитизацију ћелија глиобластома на инхибиторе Срц тирозин-киназе. Поред тога, поменути ефекти Si306 и pro-Si306 нису умањени присуством вишеструко- резистентног фенотипа, што овим једињењима даје потенцијал за лечење резистентних тумора.Knjiga sažetaka: Treći Kongres biologa Srbije, Zlatibor, Srbija 21 - 25. 9. 2022

Vogt-Koyanagi-Harada syndrome – a case report and differential diagnosis of uveitis and meningitis

Vogt-Koyanagi-Harada sindrom je autoimuna, multisistemska bolest i važan uzrok uveitisa. Ovim prikazom bolesnika naglašavamo važnost pouzdane dijagnostike te uključivanje autoimunih bolesti u diferencijalnu dijagnozu sindroma uveitisa i meningitisa.Vogt-Koyanagi -Harada syndrome is an autoimmune, multisystem disease and important cause of uveitis. In this case report we address the significance of reliable diagnostics and including autoimmune diseases in differential diagnosis of uveitis and meningitis syndrome

Design, synthesis, and biological evaluation of novel derivatives of dithiodiglycolic acid prepared via oxidative coupling of thiols.

Human thioredoxin reductase 1 (TrxR1) is a selenocysteine-containing enzyme which plays a crucial role in regulating numerous redox signalling pathways within the cell. While its functioning is important in all cells, levels of TrxR1 expression are higher in cancer cells, possibly as an adaptation to much higher levels of reactive oxygen species and the need for more extensive DNA synthesis. This makes TrxR1 an attractive target for cancer therapy development. Inspired by the structure of disulphide compounds which have advanced through various stages of clinical development, we designed a series of dithiodiglycolic acid derivatives. These were prepared from respective thiol synthons using an iodine- or benzotriazolyl chloride-promoted oxidative disulphide bond formation. Inhibition of TrxR present in cell lysates from human neuroblastoma cells (SH-SY5Y) and rat liver cells indicated several compounds with a potential for TrxR inhibition. Some of these compounds were also tested for growth inhibition against two human cancer cell lines and normal human keratinocytes

Modulation of Antioxidant Potential with Coenzyme Q10 Suppressed Invasion of Temozolomide-Resistant Rat Glioma In Vitro and In Vivo.

The main reasons for the inefficiency of standard glioblastoma (GBM) therapy are the occurrence of chemoresistance and the invasion of GBM cells into surrounding brain tissues. New therapeutic approaches obstructing these processes may provide substantial survival improvements. The purpose of this study was to assess the potential of lipophilic antioxidant coenzyme Q10 (CoQ10) as a scavenger of reactive oxygen species (ROS) to increase sensitivity to temozolomide (TMZ) and suppress glioma cell invasion. To that end, we used a previously established TMZ-resistant RC6 rat glioma cell line, characterized by increased production of ROS, altered antioxidative capacity, and high invasion potential. CoQ10 in combination with TMZ exerted a synergistic antiproliferative effect. These results were confirmed in a 3D model of microfluidic devices showing that the CoQ10 and TMZ combination is more cytotoxic to RC6 cells than TMZ monotherapy. In addition, cotreatment with TMZ increased expression of mitochondrial antioxidant enzymes in RC6 cells. The anti-invasive potential of the combined treatment was shown by gelatin degradation, Matrigel invasion, and 3D spheroid invasion assays as well as in animal models. Inhibition of MMP9 gene expression as well as decreased N-cadherin and vimentin protein expression implied that CoQ10 can suppress invasiveness and the epithelial to mesenchymal transition in RC6 cells. Therefore, our data provide evidences in favor of CoQ10 supplementation to standard GBM treatment due to its potential to inhibit GBM invasion through modulation of the antioxidant capacity

With food to health : proceedings of 11th International symposium

Proceedings contains 13 original scientific papers, 10 professional papers and 2 review papers which were presented at "10th International Scientific and Professional Conference WITH FOOD TO HEALTH", organised in following sections: Nutrition, Dietetics and diet therapy, Functional food and food supplemnents, Food safety, Food analysis, Production of safe food and food with added nutritional value

DEVELOPMENT OF RURAL TOURISM BASED ON THE BRAND OF KRKA NATIONAL PARK

Rad se bavi sve popularnijim i traženijim oblikom turizma, a to je ruralni turizam. Današnji ubrzan i stresan način života je pogodovao da ljudi sve više za odmor traže destinacije koje će im pružiti bijeg od svakodnevnice i mir, a ruralni prostor je idealan za to. Ruralno područje oko Nacionalnog parka Krka je nedovoljno iskorišteno s obzirom na to da je posjećenost samog parka svake godine sve veća. Temeljni problem su smještajni kapaciteti kojih ima nedovoljno na tom prostoru. Potrebno je ulagati u seoska domaćinstva kako bi se posjetitelji mogli zadržati nekoliko dana na toj lokaciji, a time bi se doprinijelo oživljavanju i razvitku lokalnog područja. Potrebno je brandiranje i stvaranje jedinstvene ponude koja će privući sve veći broj posjetitelja, ali na način da se ne ugrožava održivost područja.The paper deals with the increasingly popular and sought after form of tourism, which is the rural tourism. Today’s rapid and stressful way of life has made it easier for people all overlooking for vacation destinations that will allow them to escape from everyday life and peace, and the rural area is ideal for this. The rural area around Krka National Park is insufficiently utilized even due to the fact that the visits to the park itself are increasing each year. The fundamental problem is the lack of accommodation facilities in this area. It is necessary to invest in rural households to enable visitors to stay a few days at the site, and thus to contribute to the revival and development of the local area. It is necessary to create a unique branding and offers that will attract an increasing number of visitors, but in a way that does not jeopardize the viability of the area