1. Electrotransfer of plasmid DNA radiosensitizes B16F10 tumors through activation of immune responseMonika Savarin, Urška Kamenšek, Maja Čemažar, Richard Heller, Gregor Serša, 2017, izvirni znanstveni članek Povzetek: Tumor irradiation combined with adjuvant treatments, either vascular targeted or immunomodulatory, is under intense investigation. Gene electrotransfer of therapeutic genes is one of these approaches. The aim of this study was to determine, whether gene electrotransfer of plasmid encoding shRNA for silencing endoglin, with vascular targeted effectiveness, can radiosensitize melanoma B16F10 tumors. Materials and methods. The murine melanoma B16F10 tumors, growing on the back of C57Bl/6 mice, were treated by triple gene electrotransfer and irradiation. The antitumor effect was evaluated by determination of tumor growth delay and proportion of tumor free mice. Furthermore, histological analysis of tumors (necrosis, apoptosis, proliferation, vascularization, presence of hypoxia and infiltration of immune cells,) was used to evaluate the therapeutic mechanisms. Results. Gene electrotransfer of plasmid silencing endoglin predominantly indicated vascular targeted effects of the therapy, since significant tumor growth delay and 44% of tumor free mice were obtained. In addition, irradiation had minor effects on radioresistant melanoma, with 11% of mice tumor free. The combined treatment resulted in excellent effectiveness with 88% of mice tumor free, with more than half resistant to secondary tumor challenge, which was observed also with the plasmid devoid of the therapeutic gene. Histological analysis of tumors in the combined treatment group, demonstrated similar mode of action of the gene electrotransfer of plasmid encoding shRNA for silencing endoglin and devoid of it, both through the induction of an immune response. Conclusions. The results of this study indicate that irradiation can in radioresistant melanoma tumors, by release of tumor associated antigens, serve as activator of the immune response, besides directly affecting tumor cells and vasculature. The primed antitumor immune response can be further boosted by gene electrotransfer of plasmid, regardless of presence of the therapeutic gene, which was confirmed by the high radiosensitization, resulting in prolonged tumor growth delay and 89% of tumor free mice that were up to 63% resistant to secondary challenge of tumor. In addition, gene electrotransfer of therapeutic plasmid for silencing endoglin has also a direct effect on tumor vasculature and tumors cells; however in combination with radiotherapy this effect was masked by pronounced immune response.
Ključne besede: gene therapy, electrotransfer, plasmid, irradiation, immune response, melanoma
Objavljeno v DiRROS: 24.05.2024; Ogledov: 79; Prenosov: 32
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2. Adjuvant TNF-a therapy to electrochemotherapy with intravenous cisplatin in murine sarcoma exerts synergistic antitumor effectivenessMaja Čemažar, Vesna Todorović, Janez Ščančar, Urša Lampreht Tratar, Monika Savarin, Urška Kamenšek, Simona Kranjc Brezar, Andrej Cör, Gregor Serša, 2015, izvirni znanstveni članek Povzetek: Background. Electrochemotherapy is a tumour ablation modality, based on electroporation of the cell membrane, allowing non-permeant anticancer drugs to enter the cell, thus augmenting their cytotoxicity by orders of magnitude. In preclinical studies, bleomycin and cisplatin proved to be the most suitable for clinical use. Intravenous administration of cisplatin for electrochemotherapy is still not widely accepted in the clinics, presumably due to its lower antitumor effectiveness, but adjuvant therapy by immunomodulatory or vascular-targeting agents could provide a way for its potentiation. Hence, the aim of the present study was to explore the possibility of adjuvant tumour necrosis factor % (TNF-%) therapy to potentiate antitumor effectiveness of electrochemotherapy with intravenous cisplatin administration in murine sarcoma. Materials and methods. In vivo study was designed to evaluate the effect of TNF-% applied before or after the electrochemotherapy and to evaluate the effect of adjuvant TNF-% on electrochemotherapy with different cisplatin doses. Results. A synergistic interaction between TNF-% and electrochemotherapy was observed. Administration of TNF-% before the electrochemotherapy resulted in longer tumour growth delay and increased tumour curability, and was significantly more effective than TNF-% administration after the electrochemotherapy. Tumour analysis revealed increased platinum content in tumours, TNF-% induced blood vessel damage and increased tumour necrosis after combination of TNF-% and electrochemotherapy, indicating an anti-vascular action of TNF-%. In addition, immunomodulatory effect might have contributed to curability rate of the tumours. Conclusion. Adjuvant intratumoural TNF-% therapy synergistically contributes to electrochemotherapy with intravenous cisplatin administration. Due to its potentiation at all doses of cisplatin, the combined treatment is predicted to be effective also in tumours, where the drug concentration is suboptimal or in bigger tumours, where electrochemotherapy with intravenous cisplatin is not expected to be sufficiently effective.
Ključne besede: electrochemotherapy, TNF, adjuvant immunotherapy, cisplatin
Objavljeno v DiRROS: 17.04.2024; Ogledov: 160; Prenosov: 30
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3. Radiosenzibilizacija tumorjev z elektroprenosom plazmida za dve antiangiogeni tarčiMonika Savarin, Katarina Žnidar, Gregor Serša, Tilen Komel, Maja Čemažar, Urška Kamenšek, 2023, objavljeni povzetek znanstvenega prispevka na konferenci Ključne besede: miši, elektroprenos genov, gensko zdravljenje
Objavljeno v DiRROS: 19.06.2023; Ogledov: 383; Prenosov: 146
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4. Contrast-enhanced ultrasound for evaluation of tumor perfusion and outcome following treatment in a murine melanoma modelMaja Brložnik, Nina Boc, Maja Čemažar, Maša Omerzel, Monika Savarin, Nataša Kejžar, Gregor Serša, Darja Pavlin, Simona Kranjc Brezar, 2021, izvirni znanstveni članek Objavljeno v DiRROS: 23.09.2022; Ogledov: 524; Prenosov: 315
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5. Evaluation of a novel plasmid for simultaneous gene electrotransfer-mediated silencing of CD105 and CD146 in combination with irradiationMonika Savarin, Urška Kamenšek, Katarina Žnidar, Vesna Todorović, Gregor Serša, Maja Čemažar, 2021, izvirni znanstveni članek Povzetek: Targeting tumor vasculature through specific endothelial cell markers represents a promising approach for cancer treatment. Here our aim was to construct an antibiotic resistance gene-free plasmid encoding shRNAs to simultaneously target two endothelial cell markers, CD105 and CD146, and to test its functionality and therapeutic potential in vitro when delivered by gene electrotransfer (GET) and combined with irradiation (IR). Functionality of the plasmid was evaluated by determining the silencing of the targeted genes using qRT-PCR. Antiproliferative and antiangiogenic effects were determined by the cytotoxicity assay tube formation assay and wound healing assay in murine endothelial cells 2H-11. The functionality of the plasmid construct was also evaluated in malignant melanoma tumor cell line B16F10. Additionally, potential activation of immune response was measured by induction of DNA sensor STING and proinflammatory cytokines by qRT-PCR in endothelial cells 2H-11. We demonstrated that the plasmid construction was successful and can efficiently silence the expression of the two targeted genes. As a consequence of silencing, reduced migration rate and angiogenic potential was confirmed in 2H-11 endothelial cells. Furthermore, induction of DNA sensor STING and proinflammatory cytokines were determined, which could add to the therapeutic effectiveness when used in vivo. To conclude, we successfully constructed a novel plasmid DNA with two shRNAs, which holds a great promise for further in vivo testing.
Ključne besede: CD105, CD146, plasmid, gene electrotransfer
Objavljeno v DiRROS: 21.09.2022; Ogledov: 575; Prenosov: 327
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6. Genska terapija v onkologiji, prvi razvojni koraki v SlovenijiMaja Čemažar, Tanja Jesenko, Maša Omerzel, Boštjan Markelc, Urška Kamenšek, Simona Kranjc Brezar, Špela Kos, Urša Lampreht Tratar, Katarina Žnidar, Andrej Renčelj, Urška Matkovič, Teja Valant, Kristina Levpušček, Živa Modic, Tilen Komel, Tim Božič, Urša Kešar, Barbara Starešinič, Katja Uršič Valentinuzzi, Monika Savarin, Primož Strojan, Gorana Gašljević, Maja Ota, Aleš Grošelj, Črt Jamšek, Rosana Hudej, Matjaž Peterka, Franc Smrekar, Barbara Hubad, Marjan Hosta, Jaka Kužnik, Alojz Hosta, Damijan Miklavčič, Matej Reberšek, Aleksandra Cvetkoska, Anja Zajc, Janja Dermol-Černe, Nataša Tozon, Nina Milevoj, Alenka Nemec Svete, Gregor Serša, 2022, strokovni članek Povzetek: Genska terapija postaja čedalje bolj zanimiva tudi v onkologiji. Med aplikacijami je morda najzanimivejša imunostimulacija. Pripravimo lahko plazmidno DNA, ki nosi zapis za različne imunostimulatorne molekule, ki jih vnesemo v celice tumorjev ali normalnih tkiv. Ta tkiva postanejo proizvajalci teh molekul, ki lahko delujejo lokalno ali pa se izločajo tudi sistemsko v krvni obtok. Ker plazmidna DNA ne prehaja celične membrane, so potrebni dostavni sistemi, virusni ali nevirusni. V naših študijah uporabljamo predvsem nevirusni dostavni sistem – elektroporacijo. Interlevkin 12 (IL-12) je eden od zanimivih citokinov, za katerega je znano protitumorsko delovanje s spodbujanjem imunskega odziva in antiangiogenim delovanjem. Namen projekta SmartGene.si je bil pripraviti plazmid z zapisom za interlevkin 12 (plazmid phIL12) in pripraviti vse potrebno za njegovo klinično testiranje za zdravljenje kožnih tumorjev. V konzorciju smo združili moči s partnerji z akademskega in industrijskega področja. Treba je bilo pripraviti plazmid za uporabo v humani onkologiji po zahtevah Evropske agencije za zdravila (EMA). Za prijavo klinične študije na Javno agencijo za zdravila in medicinske pripomočke (JAZMP) smo morali izvesti tudi vse neklinične raziskave o varnosti in učinkovitosti zdravila. Nato je bilo treba razviti postopek priprave zdravila, zagotoviti primerne prostore za pripravo in izvedbo postopka priprave zdravila. V treh letih smo dosegli vse te zastavljene cilje in dobili dovoljenje za izvajanje klinične študije na kožnih tumorjih, ki ga je izdala JAZMP na osnovi pozitivnega mnenja Komisije Republike Slovenije za medicinsko etiko. Zdaj poteka klinična študija faze I preizkušanja plazmida phIL12 na kožnih tumorjih glave in vratu z namenom preveriti varnost in sprejemljivost genskega elektroprenosa plazmida v tumorje. Cilj študije je prav tako določiti primeren odmerek zdravila, ki bi ga v nadaljnji klinični študiji uporabili kot adjuvantno zdravljenje k ablativnim terapijam, kot sta radioterapija ali elektrokemoterapija.
Ključne besede: genska terapija, interlevkin-12, plazmidna DNA, elektroprenos genov, rak kože
Objavljeno v DiRROS: 01.07.2022; Ogledov: 1261; Prenosov: 250
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