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Cisplatina se koristi za liječenje velikog broja različitih zloćudnih tumora. Učinkovitost liječenja ograničena je pojavom ozbiljnih neželjenih pojava i/ili zbog otpornosti stanica zloćudnih tumora na liječenje. U posljednjih 18 godina se za liječenje zloćudnih tumora koriste spojevi koji moduliraju epigenom. Epigenetičke promjene su uključene, barem djelomično, u razvoj neosjetljivosti stanica zloćudnih tumora na velik broj protutumorskih lijekova. Važna epigenetička modifikacija koja je uključena u nastanak neosjetljivosti je trimetilacija lizina na položaju 27 u histonu H3 (H3K27me3). Ovu represivnu oznaku uspostavlja enzim EZH2 koji se može selektivno inhibirati lijekom tazemetostatom. Uklanjanje ove oznake kataliziraju enzimi KDM6A i KDM6B koji se mogu inhibirati spojem GSK-J4. Cilj rada bio je istražiti učinak spojeva tazemetostat i GSK-J4, u odnosu na promjenu osjetljivosti stanica na cisplatinu. Model istraživanja bile su stanice podrijetlom od zloćudnih tumora glave i vrata (Detroit 562 i FaDu) i debelog crijeva (HT-29). Kombinacije ovih spojeva s cisplatinom nisu dovoljno, ili uopće, istražene na ovim modelima. Dodatno je istražen učinak ovih spojeva u odnosu na razinu glukoze u hranjivom mediju. Cisplatina je uzrokovala stanično specifičan odgovor izmjeren primjenom funkcionalnih staničnih testova (test vijabilnosti, test proliferacije). Linija stanica FaDu pokazala se najosjetljivijom na djelovanje cisplatine, Detroit 562 umjereno osjetljivom, dok su stanice HT29 bile najotpornije. Kombiniranje cisplatine s tazemetostatom nije dovelo do dodatnog povećanja učinka cisplatine na proliferaciju stanica FaDu i Detroit 562, dok je u stanicama zloćudnog tumora debelog crijeva, HT-29, tazemetostat antagnonizirao djelovanje cisplatine. Za razliku od tazemetostata, spoj GSK-J4 sinergistički je djelovao s cisplatinom u odnosu na smanjenje proliferacije stanica Detroit 562 i HT-29. Sinergistički učinak izostao je u stanicama FaDu. Učinci kombinacija spojeva nisu se značajno razlikovali u odnosu na koncentraciju glukoze u mediju. Pozadina opaženih promjena istražila se na molekularno-genetičkoj razini, mjerenjem transkripata i proteinskih produkata gena uključenih u regulaciju staničnog ciklusa. Iako je cisplatina uzrokovala porast transkripta CDKN1A (P21) u svim linijama, u stanicama Detroit 562 i FaDu (ali ne i HT-29,) došlo je do sniženja razine P21 u ukupnim proteinima i proteinima citoplazme. Tazemetostat je uzrokovao porast P21 u svim stanicama. Također, primjena tazemetostata, samostalno ili s cisplatinom, uzrokovala je porast transkripta i proteina TGFB1 u stanicama HT-29. Porast se poklapa s povećanom proliferacijom u ovim eksperimentalnim uvjetima. Ovaj rad poslužit će kao osnova za dodatna istraživanja kojima će se ispitati mogućnost inhibicije enzima KDM6A i KDM6B u kombinaciji s cisplatinom, u pretkliničkim modelima. Također, ovo istraživanje pokazalo je i potencijalno opasne učinke tazemetostata u slučaju primjene na bolesnicima koji imaju karcinom debelog crijeva. Cisplatin is used to treat a number of various malignant tumors. The effectiveness of the treatment is limited by the occurrence of serious side effects and/or the cancer cells develop resistance to the treatment. Over the last 18 years, epigenome modulating compounds have been used to treat cancer. Epigenetic changes are involved, at least in part, in the development of cancer cell resistance to a number of antitumor drugs. An important epigenetic mark which is involved in development of resistance is trimethylation of lysine at the position 27 in histone H3 (H3K27me3). This repressive mark is established by the enzyme EZH2, which can be selectively inhibited by the drug tazemetostat. The removal of this mark is catalyzed by the enzymes KDM6A and KDM6B, which can be inhibited by the compound GSK-J4. The aim of this work was exploration of the effect of tazemetostat and GSK-J4, on sensitivity of cancer cells to cisplatin. The research was conducted using cells originating from head and neck (Detroit 562 and FaDu) and colon malignant tumors (HT-29). Combinations of tazemetostat and GSK-J4 with cisplatin have not been sufficiently, if at all, investigated in these models. Additionally, the effect of these compounds in relation to the content of glucose in the nutrient medium was investigated. The cellular response to cisplatin was cell-type specific and was measured with functional cellular assays (viability assay, proliferation assay). FaDu cell line proved to be the most sensitive to cisplatin, Detroit 562 was moderately sensitive, while HT-29 cells were the most resistant. Combining cisplatin with tazemetostat did not increase the effect of cisplatin with respect to the rate of FaDu and Detroit 562 proliferation, while in colon cancer cells, HT-29, tazemetostat antagonized the effect of cisplatin. Contrary to tazemetostat, the compound GSKJ4 exerted synergistic effect with cisplatin, which was obvious through the reduced proliferation rate of Detroit 562 and HT-29 cells. This effect was absent in FaDu cell lines. The effects of combined treatments did not differ significantly regarding the concentration of glucose in the medium. The underlying causes of the changes observed were investigated at the molecular-genetic level, by measuring the transcriptional activity, as well as the protein level of the selected genes involved in the regulation of the cell cycle and their protein products. Cisplatin application was associated with an increase of CDKN1A (P21) transcription in all cell lines. However, in Detroit 562 and FaDu, it was joined with a decrease of the P21 protein in both the total proteins and in the cytoplasmic protein fraction. This decrease was not observed in HT-29 cells. Tazemetostat caused an increase of P21 in all cell lines. Also, administration of tazemetostat, whether alone or in combination with cisplatin, caused an increase of TGFB1 168 HT-29 cells, on both, transcriptional and protein level. This increase coincides with increased proliferation under these specific experimental conditions. This work will serve as the basis for additional research that will explore the possibility of combining inhibition of enzymes KDM6A and KDM6B with cisplatin application, in preclinical cancer models. This in vitro research showed the potentially dangerous side effects of tazemetostat should it be used in patients with colon cancer.

Chemotherapy-induced nausea and vomiting has a major adverse impact in câncer patients, and this has led to considerable research in this field. There are a great number of clinical trials focusing on acute emesis and, significant strides forward have heen made with this problem. However, the pathophysiology of delayed emesis is still poorly understood and the control of it remains a therapeutic challenge. To prevent and treat chemotherapy induced nausea and vomiting, a wide variety of drugs is available. In order to prevent acute emesis induced by highly emetogenic chemotherapy, the use of both 5-HT3 receptor antagonist plus dexamethasone is the choice. For delayed emesis, metoclopramide plus dexamethasone should be considered for those patients with satisfactory control of acute episodes and for those with poor acute emesis control, the combination of 5-HT3 receptor antagonist plus dexamethasone should be used. The prevention of acute emesis induced by moderately emetogenic chemotherapy involves the use of a combination of a 5-HT3 receptor antagonist plus dexainethasone, while more well-conducted studies are necessary to define the best anti-emetic therapy for delayed emesis, since the is no study comparing the different treatments in a proper manner. Náuseas e vômitos decorrentes de quimioterapia têm um impacto negativo importante em pacientes com câncer, mas isso acabou levando a um considerável avanço em pesquisa neste campo. A grande maioria dos estudos se concentra no tratamento da emese aguda, onde se fez grandes avanços; por outro lado, a fisiopatologia da emese tardia não é tão bem entendida, constituindo-se num desafio terapêutico. A literatura mostra que o tratamento para emese aguda induzida por regimes altamente emetogênicos é a associação de antagonistas do receptor 5-HT3 mais dexametasona. Na emese tardia, metoclopramida e dexametasona é o tratamento de escolha para pacientes com bom controle dos episódios de emese prévio. Para aqueles com mau controle, sugere-se antagonistas do receptor 5-HT3 associados a dexametasona. Na prevenção da emese aguda induzida por quimioterápicos moderadamente emetogênicos, o regime mais efetivo é a combinação dos antagonistas dos receptores 5-HT3 e dexametasona. Na emese tardia, há a necessidade de mais estudos, pois até agora, não existem estudos comparando claramente os diversos tratamentos entre si.

Cilj ovog istraživanja bio je istražiti terapeutski potencijal resveratrola u kombinaciji s cisplatinom na rast tumora u hipertermalnim uvjetima u miša, odnosno djelovanje ove kombinacije na inhibiciju angiogeneze i rasta tumora te na polarizaciju makrofaga. Uz to, istraženo je može li višemodalni pristup s hipertermijom i resveratrolom dokinuti otpornost tumorskih stanica na cisplatinu kroz modulaciju aktivnosti histonskih deacetilaza (HDAC) i proteina toplinskog stresa te tako doprinijeti izravnoj toksičnosti na tumorske stanice. Tumor je izazvan injiciranjem 1×106 stanica EAT subkutano (sc) u bedro miševima soja Swiss albino. Miševi su obrađeni davanjem resveratrola per os (po) u dozi od 50 mg/kg tijekom pet dana u nizu s početkom 2. dana od injiciranja tumora i/ili cisplatinom koja je injicirana intaperitonealno (ip) u dozama od 2,5 mg/kg 10. i 12. dan te 5 mg/kg 15. dan. Neposredno nakon obrade miševi su izloženi sustavnoj hipertermiji tijekom 15 minuta pri temperaturi od 41 °C. Rezultati pokazuju da primjena resveratrola i cisplatine s hipertermijom jest učinkovit pristup u terapiji tumora. Uspješno inhibira angiogenezu i rast tumora te modulira polarizaciju makrofaga prema fenotipu M1. Također, dokida otpornost tumorskih stanica na cisplatinu kroz modulaciju aktivnosti HDAC-a i razine šaperona HSP-70 i HSP-90 te tako doprinosi povećanju životnog vijeka miševa. The aim of this study was to investigate the therapeutic potential of resveratrol in combination with cisplatin on mouse tumor growth in hyperthermal conditions, i.e. the effect of this combination on inhibition of angiogenesis and tumor development, and on macrophage polarization. In addition, it was investigated whether a multimodal approach with hyperthermia and resveratrol could abolish cisplatin resistance in tumor cells through modulation of histone deacetylases (HDAC) activity and heat shock proteins, contributing to direct toxicity on tumor cells. The tumor was induced by injecting 1×106 EAT cells subcutaneously (sc) into the thighs of Swiss albino mice. Mice were treated with resveratrol per os for five consecutive days beginning on day 2 after tumor injection and/or by injecting cisplatin intraperitoneally (ip) at a dose of 2.5 mg/kg on days 10 and 12 and a dose of 5 mg/kg on day 15. Immediately thereafter, mice were exposed to systematic hyperthermia for 15 min at a temperature of 41 °C. Results show that the administration of resveratrol and cisplatin with hyperthermia is an effective approach in tumor therapy. It successfully inhibits angiogenesis and tumor growth and modulates macrophage polarization to the M1 phenotype. Also, it abolishes tumor cells' cisplatin resistance through modulation of HDAC activity and concentration of HSP-70 and HSP-90 chaperones, contributing to the increased lifespan of mice.

Highlights Cisplatin is an antineoplastic agent used malignant diseases. Cisplatin ototoxicity is generally bilateral, irreversible, and progressive. Genistein is a phytoestrogen. Genistein functions as antioxidant and cell cycle inhibitor by inhibiting DNA topoisomerase. Genistein showed positive effects on ototoxicity with its antioxidant. Objective Cisplatin is an antineoplastic agent used in adults and children for the treatment of various malignant diseases. It can cause irreversible ototoxicity. Genistein is a phytoestrogen. Genistein functions as an antioxidant and cell cycle inhibitor by inhibiting the DNA topoisomerase and tyrosine protein kinase enzymes. The protective effect of genistein in preventing cisplatin-induced ototoxicity and levels of the oxidative stress was investigated. Methods 32 Sprague Dawley rats were used in 4 groups (control, cisplatin, cisplatin + genistein, genistein). Otoacoustic emission measurements of the distortion product were performed on the 1st, 2nd and 5th days of the test protocol. Serum malondialdehyde, superoxide dismutase, catalase, glutathione peroxidase, total antioxidant status, total oxidant status and oxidative stress index measurements were made. Results The hearing of the cisplatin + genistein group was found to be better than that of the cisplatin group. While the malondialdehyde, total oxidant status and oxidative stress index parameters decreased significantly in the cisplatin + genistein group compared to the cisplatin group, superoxide dismutase increased significantly (p < 0.05). Conclusion Genistein showed positive effects against ototoxicity with its antioxidant effect. Level of evidence Level 3. Resumo DESTAQUES A cisplatina é um agente antineoplásico usado em lesões malignas. A ototoxicidade da cisplatina é geralmente bilateral, irreversível e progressiva. A genisteína é um fitoestrógeno. A genisteína funciona como antioxidante e inibidor do ciclo celular ao inibir a topoisomerase do DNA. A genisteína apresentou efeitos positivos sobre a ototoxicidade com seu efeito antioxidante. Objetivo A cisplatina é um agente antineoplásico usado em adultos e crianças para o tratamento de diversas lesões malignas. Pode causar ototoxicidade irreversível. A genisteína é um fitoestrógeno que funciona como antioxidante e inibidor do ciclo celular ao inibir as enzimas DNA topoisomerase e tirosina-quinase. O efeito protetor da genisteína na prevenção da ototoxicidade induzida pela cisplatina e os níveis de estresse oxidativo foram investigados. Método Trinta e dois ratos Sprague Dawley foram usados em 4 grupos (controle, cisplatina, cisplatina + genisteína, genisteína). As medidas das emissões otoacústicas por produto de distorção foram tomadas nos dias 1, 2 e 5 do protocolo do teste. Foram medidos os níveis séricos de malondialdeído, superóxido dismutase, catalase, glutationa peroxidase, estado antioxidante total, estado oxidante total e índice de estresse oxidativo. Resultados A audição do grupo cisplatina + genisteína foi melhor do que a do grupo cisplatina. Enquanto os parâmetros malondialdeído, estado oxidante total e índice de estresse oxidativo diminuíram significantemente no grupo cisplatina + genisteína em comparação com o grupo cisplatina, o superóxido dismutase mostrou aumento significantemente (p < 0,05). Conclusão A genisteína apresentou efeitos positivos contra a ototoxicidade com seu efeito antioxidante. Nível de evidência Nível 3.

O estudo das propriedades e interações de drogas quimioterápicas possui um papel vital no desenvolvimento de novos tratamentos oncológicos e no aprimoramento dos que estão atualmente em uso. A cisplatina (Pt(NH3)2Cl2) e outras drogas a base de platina são medicamentos amplamente utilizados para tratar diversos tipos de câncer, incluindo testículo, ovário, pescoço, entre outros. O presente trabalho investigou a interação da cisplatina com células de glioblastoma humano da linhagem U87 a fim de descobrir se o uptake era distinto entre elas. Entender e estudar como se dá o uptake de um droga é de suma importância para a compreensão dos mecanismos de resistências associados a interação dela com as células cancerosas. As células foram tratadas com diferentes concentrações de cisplatina (10, 20 e 100 µM) por 24 horas. A análise foi realizada utilizando a técnica de µ-PIXE, com um feixe de prótons de 2,2 MeV e tamanho de aproximadamente 1,2 x 1,2 µm2 , que forneceu informação elementar da amostra e permitiu a criação de mapas elementares 2D com resolução espacial micrométrica. Medindo os sinais do Cloro e da Platina, foi possível identificar células individuais na amostra e observar quais delas possuíram um maior uptake de cisplatina, respectivamente. Além disso, foi notado que na amostra de 100 µM houve a presença de um alto sinal de Ferro correlacionando com o sinal da Platina, que não estava presente em concentraçõe menores de cisplatina. Tal resultado pode ser evidência de ferroptose, isto é, um tipo de morte de celular dependente de ferro, completamente independente da apoptose convencional. Estudos recentes já mostraram que a cisplatina pode induzir ferroptose caso a dose exceda um determinado limite. Todos os experimentos foram realizados no Laboratório de Implantação Iônica com um acelerador Tandem de 3MV. Esse trabalho também demonstrou a versatilidade e aplicabilidade da técnica de µ-PIXE e como ela pode ser utilizada para conduzir análises e experimentos multidisciplinares. The study of chemotherapy drug’s properties plays a vital role in the development of new cancerrelated treatments and the improvement of those currently in use. Cisplatin (Pt(NH3)2Cl2) and other platinum-based drugs are widely used medications that treat several different cancers, including, but not limited to, ovarian, testicular, and neck. The present work investigated the interaction of cisplatin with human glioblastoma U87 cells in order to find out if the uptake was distinct between them. Cells were treated with cisplatin at a concentration of 10, 20, and 100 µM for 24 hours. The analysis was done using the µ-PIXE technique, with a 2.2 MeV proton beam of 1.2 x 1.2 µm2 spot size, which gave us elemental information about the sample and allowed us to create 2D maps with micrometric spacial resolution. By measuring the chlorine and platinum signals, we were able to identify individual cells in the sample and detect which ones had a greater cisplatin uptake, respectively. Understanding the drug’s uptake is crucial for unraveling the mechanisms of resistance that are involved in its interaction with cancer cells. Moreover, we noticed that the 100 µM sample had a high iron signal correlating with the platinum signal, which was not present at lower treatment concentrations. This result could be a piece of evidence for ferroptosis, i.e. a type of iron-dependant cell death completely independent from regular apoptosis. Recent studies have already shown that cisplatin can induce ferroptosis in high treatment concentrations. All experiments were conducted at the Ion Implantation Laboratory with a 3MV Tandem accelerator. This work also highlighted the versatility and applicability of the µ-PIXE technique and how it can be used to perform interdisciplinary analysis.

Background: Radiotherapy of locally advanced head and neck cancer represents a major clinical challenge. Any treatment intensification aiming at improved treatment outcomes poten­tially results in a higher toxicity. The search for optimal treatment schedule involving conventional or altered fractionation of radiotherapy and the frequency and dose of concomitant cisplatin or other systemic agents has been spanning over several decades. Purpose: To evaluate long-term outcomes and toxicity of accelerated chemoradiotherapy of locally advanced squamous cell carcinoma of the head and neck (LA SCCHN). Patients and methods: Forty patients with stage III and IVA (TNM, 7th Ed.) LA SCCHN were treated with accelerated radiotherapy with a total dose of 67.5 Gy in 6 weeks delivered with simultaneous integrated boost intensity-modulated radiotherapy (SIB IMRT) and concomitant weekly cisplatin 40 mg/m2. Five-year outcomes and early and late toxicity were evaluated. Results: With the median follow-up of 47.8 months, a 5-year locoregional control rate (LCR) was 56.5%, distant control rate (DCR) was 87% and 5-year progression-free survival (PFS) and overall survival (OS) were 37 and 45%, respectively. Cisplatin cumulative dose of ≥ 200 mg/m2 was administered in 83% of patients. Grade ≥ 2 late toxicity with dietary change was observed in 21 (53%) patients. Human papillomavirus (HPV) status determined by p16 immunohistochemistry was the only significant factor in 5-year treatment outcomes analysis with LCR 100 vs. 41% (P < 0.01), DCR 100 vs. 78% (P = 0.154), PFS 80 vs. 23% (P = 0.01) and OS 80 vs. 34% (P = 0.03) for HPV positive oropharyngeal cancer (OPC) and other HPV negative LA SCCHN. Conclusion: High proportion of patients with LA SCCHN received an adequate cumulative dose of concurrent cisplatin with accelerated radiotherapy with SIB IMRT. This study demonstrated that chemoradiotherapy with weekly cisplatin resulted in favorable local control rate and survival in patients with HPV+ OPC.

Cisplatin (CP) is a commonly used, powerful antineoplastic drug, having numerous side effects. Casticin (CAS) is considered as a free radical scavenger and a potent antioxidant. The present research was planned to assess the curative potential of CAS on CP persuaded renal injury in male albino rats. Twenty four male albino rats were distributed into four equal groups. Group-1 was considered as a control group. Animals of Group-2 were injected with 5mg/kg of CP intraperitoneally. Group-3 was co-treated with CAS (50mg/kg) orally and injection of CP (5mg/kg). Group-4 was treated with CAS (50mg/kg) orally throughout the experiment. CP administration substantially reduced the activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), glutathione S-transferase (GST), glutathione reductase (GSR), glutathione (GSH) content while increased thiobarbituric acid reactive substances (TBARS), and hydrogen peroxide (H2O2) levels. Urea, urinary creatinine, urobilinogen, urinary proteins, kidney injury molecule-1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL) levels were substantially increased. In contrast, albumin and creatinine clearance was significantly reduced in CP treated group. The results demonstrated that CP significantly increased the inflammation indicators including nuclear factor kappa-B (NF-κB), tumor necrosis factor-α (TNF-α), Interleukin-1β (IL-1β), Interleukin-6 (IL-6) levels and cyclooxygenase-2 (COX-2) activity and histopathological damages. However, the administration of CAS displayed a palliative effect against CP-generated renal toxicity and recovered all parameters by bringing them to a normal level. These results revealed that the CAS is an effective compound having the curative potential to counter the CP-induced renal damage. Resumo A cisplatina (CP) é uma droga antineoplásica poderosa, comumente usada, com vários efeitos colaterais. Casticin (CAS) é considerado um eliminador de radicais livres e um potente antioxidante. A presente pesquisa foi planejada para avaliar o potencial curativo da CAS em lesão renal induzida por PC em ratos albinos machos. Vinte e quatro ratos albinos machos foram distribuídos em quatro grupos iguais. O Grupo 1 foi considerado grupo controle. Os animais do Grupo 2 foram injetados com 5 mg / kg de PB por via intraperitoneal. O Grupo 3 foi cotratado com CAS (50 mg / kg) por via oral e injeção de CP (5 mg / kg). O Grupo 4 foi tratado com CAS (50 mg / kg) por via oral durante todo o experimento. A administração de CP reduziu substancialmente as atividades de catalase (CAT), superóxido dismutase (SOD), peroxidase (POD), glutationa S-transferase (GST), glutationa redutase (GSR), glutationa (GSH), enquanto aumentou as substâncias reativas ao ácido tiobarbitúrico (TBARS) e níveis de peróxido de hidrogênio (H2O2). Os níveis de ureia, creatinina urinária, urobilinogênio, proteínas urinárias, molécula 1 de lesão renal (KIM-1) e lipocalina associada à gelatinase de neutrófilos (NGAL) aumentaram substancialmente. Em contraste, a albumina e a depuração da creatinina foram significativamente reduzidas no grupo tratado com PC. Os resultados demonstraram que a CP aumentou significativamente os indicadores de inflamação, incluindo fator nuclear kappa-B (NF-κB), fator de necrose tumoral-α (TNF-α), interleucina-1β (IL-1β), interleucina-6 (IL-6) níveis e atividade da ciclooxigenase-2 (COX-2) e danos histopatológicos. No entanto, a administração de CAS apresentou um efeito paliativo contra a toxicidade renal gerada por CP e recuperou todos os parâmetros, trazendo-os a um nível normal. Estes resultados revelaram que o CAS é um composto eficaz com potencial curativo para combater o dano renal induzido por CP.

Introduction: Cisplatin is one of the main chemotherapeutic agents used for the treatment of many types of cancer. However, ototoxicity, one of the most serious side effects of cisplatin, restricts its usage. Objective: We aimed to investigate the protective effects of whortleberry extract against cisplatin-induced ototoxicity by evaluating hearing and histopathological cochlear damage and by measuring the biochemical parameters affected byoxidative stress. Methods: Forty-eight male rats were included in the study after performing Distortion Product Otoacoustic Emission test to confirm that their hearing levels were normal. The rats were randomly divided into six groups: the control group, the sham group, and, which received only whortleberry extract, only cisplatin, cisplatin + 100 mg whortleberry extract, cisplatin + 200 mg whortleberry extract, respectively. Audiologic investigation was performed by performing the Distortion Product Otoacoustic Emission test at the beginning and at the eighth day of the study. Cardiac blood samples were collected for biochemical analysis, and the rats were sacrificed to obtain cochlear histopathological specimens on the eighth day. Results: The results revealed that whortleberry protects hearing against cisplatin-induced ototoxicity independent of the dose. However, high doses of whortleberry extract are needed to prevent histopathological degeneration and oxidative stress. Conclusion: The results obtained in this study show that whortleberry extract has a protective effect against cisplatin-induced ototoxicity. Resumo: Introdução: A cisplatina é um dos principais agentes quimioterápicos utilizados para o tratamento de muitos tipos de câncer. No entanto, a ototoxicidade, um dos efeitos colaterais mais graves da cisplatina, restringe seu uso. Objetivo: Nosso objetivo foi investigar os efeitos protetores do extrato de uva-do-monte contra a ototoxicidade induzida por cisplatina, avaliar o dano auditivo e histopatológico coclear e medir os parâmetros bioquímicos afetados pelo estresse oxidativo. Método: Foram incluídos no estudo 48 ratos machos após teste de emissão otoacústica evocada por produto de distorção para confirmar que seus níveis de audição eram normais. Os ratos foram divididos aleatoriamente em seis grupos: o grupo controle, o grupo simulado, o que recebeu apenas extrato de uva-do-monte, o que recebeu apenas cisplatina, o que recebeu cisplatina + 100 mg de extrato de uva-do-monte e o que recebeu cisplatina + 200 mg de extrato de uva-do-monte, respectivamente. A investigação audiológica foi feita através do teste de emissão otoacústica de produto de distorção no início e no oitavo dia do estudo. As amostras de sangue cardíaco foram coletadas para análise bioquímica e os ratos foram sacrificados para obtenção de espécimes histopatológicos cocleares no oitavo dia. Resultados: Os resultados revelaram que o extrato de uva-do-monte protege a audição contra a ototoxicidade induzida por cisplatina, independentemente da dose. No entanto, são necessárias doses elevadas do extrato para evitar a degeneração histopatológica e o estresse oxidativo. Conclusão: Os resultados obtidos neste estudo mostram que o extrato de uva-do-monte tem um efeito protetor contra a ototoxicidade induzida por cisplatina. Keywords: Ototoxicity, Cisplatin, Whorleberry extract, Palavras-chave: Ototoxicidade, Cisplatina, Extrato de uva-do-monte

At present, nuclear condensation and fragmentation have been estimated also using Hoechst probes in fluorescence microscopy and flow cytometry. However, none of the methods used the Hoechst probes for quantitative spectrofluorometric assessment. Therefore, the aim of the present study was to develop a spectrofluorometric assay for detection of nuclear condensation and fragmentation in the intact cells. We used human hepatoma HepG2 and renal HK-2 cells cultured in 96-well plates treated with potent apoptotic inducers (i.e. cisplatin, staurosporine, camptothecin) for 6-48 h. Afterwards, the cells were incubated with Hoechst 33258 (2 mu g/mL) and the increase of fluorescence after binding of the dye to DNA was measured. The developed spectrofluorometric assay was capable to detect nuclear changes caused by all tested apoptotic inducers. Then, we compared the outcomes of the spectrofluorometric assay with other methods detecting cell impairment and apoptosis (i.e. WST-1 and glutathione tests, TUNEL, DNA ladder, caspase activity, PARP-1 and JNKs expressions). We found that our developed spectrofluorometric assay provided results of the same sensitivity as the TUNEL assay but with the advantages of being fast processing, low-cost and a high throughput. Because nuclear condensation and fragmentation can be typical markers of cell death, especially in apoptosis, we suppose that the spectrofluorometric assay could become a routinely used method for characterizing cell death processes. V současné době se k detekci jaderné kondenzace a fragmentace využívají fluorescenční sondy Hoechst. Žádná z metod však nepoužívá sondy Hoechst pro kvantitativní spektrofluorometrické hodnocení. Cílem této studie bylo vyvinout spektrofluorometrický test pro detekci jaderné kondenzace a fragmentace v intaktních buňkách. Použili jsme buňky lidského hepatomu HepG2 a renální HK-2 buňky kultivované v 96-jamkových inkubovanými s apoptotickými induktory (tj. cisplatinou, staurosporinem, kamptotecinem) po dobu 6-48 hodin. Poté byly buňky inkubovány s Hoechst 33258 (2 ug/ml) a bylo detekováno zvýšení intenzity fluorescence po navázání barviva na DNA. Vyvinutý spektrofluorometrický test byl schopen detekovat jaderné změny způsobené všemi testovanými apoptotickými induktory. Poté jsme výsledky spektrofluorometrického testu porovnali s dalšími metodami detekujícími poškození buněk a apoptózu (tj. testy WST-1 a glutathionu, TUNEL, DNA ladder, aktivita kaspázy, exprese PARP-1 a JNKs). Zjistili jsme, že náš vyvinutý spektrofluorometrický test poskytuje výsledky se stejnou citlivostí jako test TUNEL, ale s výhodami rychlého zpracování, nízkých nákladů a vysokého výkonu. Protože jaderná kondenzace a fragmentace mohou být typickými markery buněčné smrti, zejména při apoptóze, předpokládáme, že spektrofluorometrický test by se mohl stát rutinně používanou metodou pro charakterizaci procesů buněčné smrti.

A administração continuada de cisplatina (CDDP), quimioterápico usado no tratamento de vários tipos de tumores sólidos, é limitada em função de reações adversas, como nefrotoxicidade, hepatotoxicidade, neurotoxicidade, mielotoxicidade e ototoxicidade. Na tentativa de contornar esses inconvenientes e melhorar o índice terapêutico da CDDP, modificações farmacotécnicas têm sido propostas, como a encapsulação da CDDP em sistemas de liberação de fármacos, tais como os lipossomas. Nesse sentido, foi proposto o desenvolvimento de lipossomas termossensíveis de cisplatina não funcionalizado (LTS-CDDP), funcionalizado com ácido hialurônico (AH) por interação eletrostática (LTS-CDDP-AH-1) e funcionalizado com AH por ligação covalente (LTS-CDDP-AH-2), no intuito de proporcionar um direcionamento ativo para a região tumoral. Inicialmente foi realizado um estudo de caracterização das formulações desenvolvidas, por meio da associação das técnicas espalhamento dinâmico da luz (DLS), microcalorimetria e espalhamento de raio-X a baixo ângulo (SAXS). A taxa de encapsulação de CDDP foi avaliada por cromatografia líquida de alta eficiência por um método de derivatização com dietilditiocarbamato. Em seguida, foi avaliada a citotoxicidade frente as células tumorais MDA-MB-231, bem como a toxicidade in vivo em camundongos Swiss sadios. Os resultados de caracterização mostraram diâmetro médio menor que 200 nm e índice de polidispersão (PDI) sugestivos de formulações homogêneas (< 0,2), indicando a ausência de agregação de vesículas mesmo após funcionalização com AH. A eficiência do revestimento na superfície do lipossoma foi atribuída a valores de potencial zeta próximos da neutralidade. Os dados de DLS mostraram uma redução significativa no diâmetro médio e contagem de partículas (Kcps) das formulações avaliadas a 40oC, e o revestimento com AH não alterou a temperatura de transição de fase das formulações. A encapsulação de CDDP foi de 9,3 ± 0,7% para LTS-CDDP-AH-2, 16,1 ± 1,9% para LTS-CDDP-AH-1 e 13,7 ± 0,9% para LTS-CDDP. O perfil obtido por SAXS para todas as formulações estudadas foi característico de uma organização lamelar independente da temperatura avaliada e apresentou dilatação da bicamada, causada por desorganização na estrutura dos lipídeos, confirmando a alteração conformacional devido ao aquecimento. No entanto, o perfil de liberação in vitro sugeriu uma possível adsorção do fármaco na bicamada fosfolipídica ocasionando uma taxa de difusão de CDDP antes de atingir a Tc (42oC), para LTS-CDDP e LTS-CDDP-AH-2. Para o LTS-CDDP-AH-1, a presença do polímero pode estar modulando essa difusão, gerando um perfil de liberação mais controlado e lento. Os resultados biológicos mostraram que LTS-CDDP apresentou maior citotoxicidade quando comparado com CDDP livre, além de levar ao aumento da ocorrência de senescência. O uso de hipertermia nos grupos tratados com LTS-CDDP e LTS-CDDP-AH-1 aumentou a ocorrência de apoptose em relação aos grupos sem hipertermia. No estudo in vivo, foi observado maior toxicidade da formulação catiônica para células saudáveis, sendo observado a ocorrência de nefrotoxicidade nos animais tratados com LTS-CDDP. Enquanto que, com o uso do ligante AH, os efeitos adversos conhecidos relacionados ao uso de CDDP foram eliminados, uma vez que os animais tratados com essa formulação não apresentaram alterações significativas nos exames hematológicos e bioquímicos, bem como nas análises histológicas. Sendo assim, a formulação de CDDP proposta, termossensível e contendo AH por interação eletrostática, apresenta características adequadas para tratamento do câncer por via intravenosa, em associação com hipertermia moderada, podendo ser capaz de reduzir a toxicidade relacionada a CDDP, representando uma alternativa potencial para veiculação desse fármaco. The continuous administration of cisplatin (CDDP), a chemotherapeutic agent used to treat various types of solid tumors, is limited due to adverse reactions, such as nephrotoxicity, hepatotoxicity, neurotoxicity, myelotoxicity, and ototoxicity. In an attempt to circumvent these inconveniences and improve the therapeutic index of CDDP, pharmacotechnical modifications have been proposed, such as the encapsulation of CDDP in drug delivery systems, like liposomes. In this sense, it was proposed to develop a thermosensitive liposome of nonfunctionalized cisplatin (TSL-CDDP), functionalized with hyaluronic acid (HA) by electrostatic interaction (TSL-CDDP-HA-1) and functionalized with HA by covalent bond (TSL-CDDP-SA-HA-2), in order to provide an active targeting for the tumor region. Initially, a detailed study was carried out to characterize the formulations developed, through the association of dynamic light scattering (DLS), microcalorimetry, and low angle X-ray scattering (SAXS) techniques. The CDDP encapsulation rate was evaluated by high performance liquid chromatography using a diethyldithiocarbamate derivatization method. Then, cytotoxicity against MDA-MB-231 tumor cells was evaluated, as well as in vivo toxicity in healthy Swiss mice. The characterization results showed an average diameter less than 200 nm and a polydispersity index (PDI) suggestive of homogeneous formulations (< 0.2), indicating the absence of vesicle aggregation even after functionalization with HA. The efficiency of the HA-coating of liposome was attributed to values of zeta potential close to neutrality. The DLS data showed a significant reduction in the mean diameter and Kcps (Kilo counts per second) of the formulations evaluated at 40oC, and the coating with HA did not alter the phase transition temperature of the formulations. CDDP encapsulation was 9.3 ± 0.7% for TSL-CDDP-SA-HA, 16.1 ± 1.9% for TSL-CDDP-HA and 13.7 ± 0.9% for TSL -CDDP. The profile obtained by SAXS for all the formulations studied was characteristic of a lamellar organization independent of the evaluated temperature and presented dilation of the bilayer, caused by disorganization in the lipid structure, confirming the conformational alteration due to heating. However, the in vitro release profile suggested possible drug adsorption in the phospholipid bilayer causing a diffusion rate of CDDP before reaching Tc (42oC), for TSLCDDP and TSL-CDDP-SA-HA. For TSL-CDDP-HA, the presence of the polymer may be modulating this diffusion, generating a more controlled and slower release profile. The biological results showed that TSL-CDDP have greater cytotoxicity when compared to free CDDP, in addition to leading to an increase in the occurrence of senescence. The use of hyperthermia in the groups treated with LTS-CDDP and LTS-CDDP-HA increased the occurrence of apoptosis compared to groups without hyperthermia. In the in vivo study, greater toxicity of the cationic formulation was observed for healthy cells, with the occurrence of nephrotoxicity in animals treated with LTS-CDDP. While, with the use of the HA ligand, the known adverse effects related to the use of CDDP were eliminated, since the animals treated with this formulation did not show significant changes in hematological and biochemical tests, as well as in histological analyzes. Thus, the proposed formulation of CDDP, thermosensitive and containing HA by electrostatic interaction, has adequate characteristics for cancer treatment intravenously, in association with moderate hyperthermia, and may be able to reduce CDDPrelated toxicity, representing a potential alternative for the delivery of this drug.

Cilj ovog istraživanja bio je istražiti sinergistički učinak sustavne hipertermije uz nanokristale resveratrola i cisplatinu na inhibiciju brzorastućeg EAT, preživljavanje miševa, polarizaciju makrofaga te sposobnost nanokristala resveratrola u smanjenju toksičnih učinaka cisplatine i hipertermije u jetri i bubregu miševa. Miševima soja Swiss albino izazvan je tumor injiciranjem 1x106 stanica EAT subkutano u bedro, a zatim su obrađeni injiciranjem nanokristala resveratrola u dozi 50 mg/kg per os tijekom 5 dana u nizu te cisplatine u dozi 2,5 mg/kg 10. i 12. dan te u dozi 5 mg/kg 14. dan uz izlaganje sustavnoj hipertermiji pri 41°C. Dobiveni rezultati pokazuju da samostalna primjena nanokristala resveratrola i izlaganje hipertermiji vodi rastu tumora dok primjena nanokristala resveratrola i cisplatine uz izlaganje sustavnoj hipertermiji ostvaruje izraziti antitumorski učinak inhibicijom rasta EAT u solidnom obliku, ali ne pridonosi znatnijem povećanju preživljavanja životinja. Injiciranje cisplatine pri hipertermalnim uvjetima povećava životni vijek miševa za 47% u odnosu na kontrolu. Temeljem dobivenih rezultata možemo zaključiti da nanokristali resveratrola mogu polučiti antioksidacije i/ili prooksidacijske učinke u različitim mikrookolišnim uvjetima, ali i sudjelovati u povećanju makrofagne plastičnosti i polarizacije te zaštititi bubreg i jetru od toksičnosti izazvane cisplatinom. The aim of this study was to investigate the synergistic effect of systemic hyperthermia with resveratrol nanocrystals and cisplatin on the inhibition of fast-growing EAT, mouse survival, macrophage polarization, and the ability of resveratrol nanocrystals to reduce the toxic effects of cisplatin and hyperthermia. In Swiss albino mice tumor were induced by injecting 1x106 EAT cells subcutaneously into the thigh and then treated by injecting resveratrol nanocrystals at a dose of 50 mg/kg per os for 5 consecutive days and cisplatin at a dose of 2,5 mg/kg day 10 and 12 and at a dose of 5 mg/kg on day 14 with exposure to systemic hyperthermia at 41°C. The results show that the use of resveratrol nanocrystals alone and exposure to hyperthermia leads to tumor growth, while the use of resveratrol and cisplatin nanocrystals with exposure to systemic hyperthermia has a pronounced antitumor effect by inhibiting EAT growth in solid form, but does not significantly increase animal survival. Injection of cisplatin under hyperthermal conditions increased the lifespan of mice by 47% compared to control. Based on the obtained results, we can conclude that resveratrol nanocrystals have antioxidant and/or prooxidative effects in various microenvironmental conditions, but also participate in increasing macrophage plasticity and polarization and protect the kidney and liver from cisplatin-induced toxicity.

Submitted by (lucia.rodrigues@ufrpe.br) on 2022-12-23T15:04:34Z No. of bitstreams: 1 Thae Lanne Barbosa Gama Lins.pdf: 5463267 bytes, checksum: 6c6b4dc640d5e323ed2b8ae94d1afc4c (MD5) Made available in DSpace on 2022-12-23T15:04:34Z (GMT). No. of bitstreams: 1 Thae Lanne Barbosa Gama Lins.pdf: 5463267 bytes, checksum: 6c6b4dc640d5e323ed2b8ae94d1afc4c (MD5) Previous issue date: 2021-02-26 Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq The aims of this study were to analyze the effects of rutin on the follicular development after in vitro culture of ovine ovarian tissue and against the ovarian toxicity induced by cisplatin or doxorubicin in mice, and to verify the possible involvement of the phosphatidylinositol-3-kinase (PI3K) signaling pathway, and its members such as Protein kinase B (AKT), phosphatase and tension homolog (PTEN) and forkhead box O3a (FOXO3a) in the rutin actions in the ovary of these species. For chapter 1 of this thesis, ovine ovarian fragments were cultured in α-minimum essential medium alone (α-MEM+) or in this medium supplemented with 0.1; 1 or 10 μg/mL rutin (chapter 1) for 7 days. Inhibition of PI3K activity was performed in fragments cultured with LY294002. The following endpoints were analysed: follicle survival, activation and growth of primordial follicles, apoptosis and AKT phosphorylation (p-AKT). The results showed that 1 μg/mL rutin has higher percentage of normal follicles, activation and growth (P

Cilj ovog istraživanja bio je istražiti združeno djelovanje citostatika cisplatine i resveratrola na inhibiciju angiogeneze i razvoja tumora, povećanje životnog vijeka domaćina, te istražiti aktivnost makrofaga u tkivu tumora kroz analizu inducibilne dušik oksid sintaze. Uz to cilj je bio utvrditi kako višekratno djelovanje citostatika djeluje na razinu proteina toplinskog stresa i da li obrada resveratrolom modulira njihovu aktivnost vodeći dokidanju rezistencije tumorskih stanica na citostatik. Tumor je izazvan injiciranjem 1x106 stanica EAT subkutano (sc) u bedro miševa soja Swiss albino. Obrada životinja s EAT započeta je unosom resveratrola per os u dozi od 50 mg/kg tijekom 5 dana u nizu s početkom 2. dana od injiciranja tumora dok je cisplatina injicirana u dozi od 2,5 mg/kg 10. i 12. dana te dozom od 5 mg/kg 15. dana. Dobiveni rezultati pokazuju da resveratrol združen s cisplatinom može inhibirati proces angiogeneze, usporiti rast tumora te povećati životni vijek nositelja tumora jačanjem imunomodulatorne aktivnosti domaćina kroz modulaciju proteina toplinskog stresa HSP-90 i HSP-70 i smanjuje štetne učinke cisplatine na normalne stanice i tkiva, što ukazuje na mogućnost kliničke uporabe ove kombinacije The aim of this study was to investigate the combined effect of cytostatic cisplatin and resveratrol on inhibition of angiogenesis and tumor development, increase of host lifespan, and to investigate macrophage activity in tumor tissue through analysis of inducible nitric oxide synthase. In addition, the aim was to determine how the repeated action of cytostatics affects the level of heat shock proteins and whether resveratrol treatment modulates their activity leading to the abolition of tumor cell resistance to cytostatics. The tumor was induced by injecting 1x106 EAT cells subcutaneously (sc) into the thighs of Swiss albino mice. Treatment of animals with EAT was initiated by administration of resveratrol per os at a dose of 50 mg/kg for 5 consecutive days beginning on day 2 after tumor injection while cisplatin was injected at a dose of 2.5 mg/kg on days 10 and 12 and at a dose of 5 mg/kg on day 15. The results show that cisplatin combined with resveratrol can inhibit angiogenesis, slow tumor growth, and increase host lifespan by enhancing host immunomodulatory activity by modulating heat shock proteins HSP-90 and HSP70 and reducing the adverse effects of cisplatin on normal cells and tissues, which suggest the possibility of clinical use of this combination.

This article focuses on an analysis of the years 1820-1823 in the city of Montevideo. The capital of the Eastern Province was occupied by Portuguese troops in 1817 and formally incorporated in 1821, by means of an Extraordinary Congress, into the territory of the Portuguese Braganza Monarchy. Because of this, when the Second Liberal Revolution triumphed in Spain in 1820, and the first Portuguese one in August of the same year, the province joined the Portuguese constitutionalist movement and became the Cisplatine Province. In these pages we will see how the process of incorporation into the Brigantine Monarchy took place and how Montevideo experienced the disputes between King João VI and the Prince Regent, while the latter was planning the Brazilian declaration of independence throughout the year 1822. El presente trabajo se centra en analizar los años de 1820-1823 en la ciudad de Montevideo. La capital de la Provincia Oriental fue ocupada en 1817 por las tropas portuguesas y en 1821 formalizó —mediante un Congreso Extraordinario— la incorporación del territorio a la monarquía portuguesa de los Braganza. Es por ello que, cuando triunfó la segunda revolución liberal en España en 1820 y la primera portuguesa, en el mes de agosto de ese mismo año, la provincia, convertida en la Cisplatina, se adhirió al movimiento constitucional portugués. A lo largo de estas páginas veremos cómo fue el proceso de incorporación del territorio a la monarquía bragantina, y cómo se vivió en Montevideo la disputa entre el rey João VI y el príncipe regente don Pedro cuando este último planificó la declaración de independencia del Brasil a lo largo del año de 1822.

Cilj ovog istraživanja bio je istražiti združeno djelovanje citostatika cisplatine i resveratrola na inhibiciju angiogeneze i razvoja tumora, povećanje životnog vijeka domaćina, te istražiti aktivnost makrofaga u tkivu tumora kroz analizu inducibilne dušik oksid sintaze. Uz to cilj je bio utvrditi kako višekratno djelovanje citostatika djeluje na razinu proteina toplinskog stresa i da li obrada resveratrolom modulira njihovu aktivnost vodeći dokidanju rezistencije tumorskih stanica na citostatik. Tumor je izazvan injiciranjem 1x106 stanica EAT subkutano(sc) u bedro miševa soja Swiss albino. Obrada životinja s EAT započeta je unosom resveratrola per os u dozi od 50 mg/kg tijekom 5 dana u nizu s početkom 2. dana od injiciranja tumora dok je cisplatina injicirana u dozi od 2, 5 mg/kg 10. i 12. dana te dozom od 5 mg/kg 15. dana. Dobiveni rezultati pokazuju da resveratrol združen s cisplatinom može inhibirati proces angiogeneze, usporiti rast tumora te povećati životni vijek nositelja tumora jačanjem imunomodulatorne aktivnosti domaćina kroz modulaciju proteina toplinskog stresa HSP-90 i HSP-70 i smanjuje štetne učinke cisplatine na normalne stanice i tkiva, što ukazuje na mogućnost kliničke uporabe ove kombinacije.

Submitted by António Freitas (amsf@uma.pt) on 2021-03-04T14:19:02Z No. of bitstreams: 1 20_PhD_Thesis_Chemistry_DMaciel.pdf: 12698884 bytes, checksum: 272f3205b1feb038bd18c8308d2a70e2 (MD5) Made available in DSpace on 2021-03-04T14:19:02Z (GMT). No. of bitstreams: 1 20_PhD_Thesis_Chemistry_DMaciel.pdf: 12698884 bytes, checksum: 272f3205b1feb038bd18c8308d2a70e2 (MD5) Previous issue date: 2020-12-16

O cancro corresponde a um conjunto vasto de patologias que têm em comum o crescimento celular desregulado, o que leva à formação de tumores que invadem tecidos adjacentes ou distantes, através de diversos mecanismos de transporte. Atualmente, o grupo de doenças designadas por cancro é uma das principais causas de morte a nível global, sendo que o seu tratamento continua a ser um desafio. Desde as últimas décadas do sec. XX que se tem assistido a um desenvolvimento notável no que diz respeito ao tratamento deste tipo de patologias, quer em termos cirúrgicos, quer na descoberta de novos fármacos e de novas estratégias de abordar a doença. Invariavelmente, o tratamento do cancro não é isento de efeitos secundários significativos e a sua eficácia depende de diversos fatores que incluem o tipo de cancro, o estádio da doença, o tipo de fármaco, o ganho de resistência ao fármaco, bem como características do próprio indivíduo. A descoberta da cisplatina em 1968 e posterior aprovação para o tratamento tumoral, levou a uma vasta investigação envolvendo diversas classes de complexos de platina. No entanto até ao presente, apenas um reduzido número justificou a aprovação para uso clínico. Nos anos mais recentes tem ressurgido o interesse pelos complexos de platina, sendo que os complexos de Pt (IV) têm mostrado resultados bastante promissores. Estes complexos são considerados pró-fármacos e, sendo cineticamente mais inertes do que os complexo de Pt (II), espera-se que apresentem menores efeitos secundários. A forma ativa resulta da eliminação redutiva de dois ligandos levando à formação do complexo de Pt (II), sendo que os ligandos eliminados podem também desempenhar um papel importante no mecanismo de atuação do fármaco. Ao longo desta monografia é dada uma visão geral da investigação e uso de diversas classes de complexos de platina no tratamento tumoral, sendo abordados exemplos que ilustram as diferentes características e potencialidades destes complexos. Cancer corresponds to a vast set of pathologies that have in common unregulated cells growth leading to tumors that invade adjacent or distant tissues, through various transport mechanisms. Currently, the group of diseases designated as cancer is one of the main causes of death on a global level, and its treatment remains a challenge. Since the last decades of the twentieth century, there has been a remarkable development in the treatment of this type of pathologies, both in surgical terms and in the discovery of new drugs and new strategies to address the disease. Notwithstanding, most cancer treatments show significant side effects and its effectiveness is driven by factors that include the type of cancer, the stage of the disease, the type of drug, the gain of resistance to the drug, as well as characteristics of the individual himself. The discovery of cisplatin in 1968 and subsequent approval for tumor treatment, led to extensive research involving several classes of platinum complexes. Since then, only a small number justified the approval for clinical use. In recent years, interest in platinum complexes has resurfaced, and Pt (IV) complexes have shown very promising results. These complexes are considered pro-drugs and, being kinetically more inert than Pt (II) complexes, they are expected to present less side effects. The active form results from the reductive elimination of two ligands leading to the formation of the Pt (II) complex, and the eliminated ligands may also play an important role in the mechanism of action of the drug. Throughout this monograph an overview is given of the investigation and use of various classes of platinum complexes in tumor treatment, with examples illustrating the different characteristics and potentials of these complexes.

Introduction Platinum-based chemotherapeutics play an important role in the treatment of cancer at different levels and are the most cited ototoxic agents when scientific evidence is analyzed. Objective To present scientific evidence based on a systematic literature review, PRISMA, in order to systematize information on the ototoxic effects of using antineoplastic drugs. Methods For the selection of studies, the combination based on the Medical Subject Heading Terms (MeSH) was used. The Medline (Pubmed), LILACS, SciELO, SCOPUS, WEB OF SCIENCE and BIREME databases were used, without restriction of language, period, and location. Evaluation of the quality of the articles was carried out, which included articles with a minimum score of 6 in the modified scale of the literature. The designs of the selected studies were descriptive, cohort, and cross-sectional, which were related to the research objective. Results Three articles were included in this systematic review. The ototoxicity caused by cisplatin alone varied from 45% to 83.3%, while that caused by the use associated with carboplatin varied from 16.6% to 75%. There was a significant variation in the cumulative doses of these antineoplastic agents, both in isolated and in combination. Auditory changes, especially at high frequencies, were evident after completion of treatment. Conclusion Auditory changes after the use of platinum-based antineoplastic drugs were found, however, there was an important heterogeneity regarding the frequency of ototoxicity and the cumulative dose of the drugs used. Resumo Introdução Os quimioterápicos à base de cisplatina desempenham papel importante no tratamento do câncer em diversos níveis e são os agentes ototóxicos mais citados quando analisadas evidências científicas. Objetivo Apresentar evidências científicas com base em revisão sistemática da literatura (PRISMA), com o intuito de sistematizar informações sobre os efeitos ototóxicos do uso de medicamentos antineoplásicos. Método Para a seleção dos estudos foi usada a combinação baseada no Medical Subject Heading Terms (MeSH). Foram usadas as bases de dados Medline (Pubmed), Lilacs, SciELO, Scopus, Web of Science e Bireme, sem restrição de idioma, período e localização. Foi feita avaliação da qualidade dos artigos, na qual se incluíam artigos com nota mínima 6 na escala modificada da literatura. Os desenhos dos estudos selecionados foram do tipo descritivo, coorte e transversal, os quais estavam relacionados com o objetivo da pesquisa. Resultados Três artigos foram admitidos para esta revisão sistemática. A ototoxicidade causada pela cisplatina isoladamente variou de 45% a 83,3%, enquanto a causada pelo uso associado com a carboplatina variou de 16,6% a 75%. Verificou-se uma variação significativa nas doses cumulativas desses antineoplásicos, tanto no uso isolado quanto em combinação. Alterações auditivas, principalmente em altas frequências, foram evidenciadas após finalização do tratamento. Conclusão Alterações auditivas após o uso de medicamentos antineoplásicos à base de platina foram constatadas, porém verificou-se uma importante heterogeneidade quanto à frequência da ototoxicidade e a dose cumulativa das drogas usadas.

Tese (doutorado)—Universidade de Brasília, Faculdade de Medicina, Programa de Pós-Graduação em Patologia Molecular, 2020. A resposta ao dano no DNA (DDR) é essencial para a manutenção do bom funcionamento da célula. Esta resposta consiste na ativação de checkpoint do ciclo celular e o mecanismo de reparo de DNA. Diferentes vias de reparo são ativadas dependendo do tipo de lesão. A cisplatina é uma droga intercalante que provoca adutos no DNA e ligações interfitas. O peróxido de hidrogênio (H2O2) é um agente oxidante que, em concentrações suprafisiológicas, causa dano ao DNA e outras moléculas. Os principais danos causados pelo estresse oxidativo são modificações de base e quebra de fita de DNA. Existem evidências de que o Trypanosoma cruzi, protozoário causador da doença de Chagas, atue de diversas maneiras no metabolismo da célula hospedeira, incluindo o metabolismo de DNA. Neste trabalho, analisamos a influência de duas cepas de T. cruzi, Berenice (DTU TcII) e Colombiana (DTU TcI), na resposta ao dano de DNA em células L6, de miócitos de rato. As células receberam tratamentos em duas concentrações diferentes de cisplatina e H2O2 e tiveram diversos aspectos da sua biologia celular avaliados, como viabilidade, proliferação, morfologia, degradação de DNA e expressão de genes de reparo e de ciclo celular. Percebe-se que a célula reage ao dano de DNA de forma diferente dependendo da concentração do composto usado, seja cisplatina, seja H2O2. O tratamento com cisplatina mostrou que a cepa Berenice alterou a resposta ao dano, aumentando a intensidade de algumas vias de reparo (ex. MMR) e diminuindo a intensidade de resposta a quebras de dupla-fita (DSBs), o que provocou maior degradação de DNA e maior mortalidade. Também houve maior proliferação em células infectadas com Berenice e tratadas com cisplatina. As células infectadas por Colombiana, por outro lado, apresentaram um perfil de resistência à cisplatina, com ativação de diferentes vias eficazes ao reparo de adutos de DNA (como NER). Os resultados levantaram a hipótese se a infecção por Colombiana estimula o reparo alternativo via retrotransposon LINE-1. Também foi verificado um perfil de senescência destas células, assim como em células não infectadas. O tratamento com H2O2 mostrou que a infecção pelo T. cruzi pode atuar como um elemento estressor ou protetor do DNA hospedeiro, dependendo da cepa utilizada e da concentração de H2O2. Diferenças na degradação de DNA (DSB ou SSB) sugerem que diferentes mecanismos estão atuando no reparo de DNA em cada grupo analisado. Também foi encontrada diferença na expressão de genes em células infectadas (ex. BER e HR) com a cepa Berenice, que diminuíram a intensidade de resposta no dano moderado. A infecção pela cepa Colombiana impediu a ativação de muitas das vias de resposta ao H2O2 (NER e MMR). Como, neste caso, a mortalidade não se alterou em relação ao controle, questiona-se uma influência direta do parasito no reparo de DNA do hospedeiro. As descobertas apresentadas neste trabalho contribuem para a melhor compreensão da relação parasito-hospedeiro e pode auxiliar tanto na melhor compreensão da patologia da doença de Chagas, como também ter aplicações em outras áreas, como a da pesquisa em câncer e trazer explicações para o dúbio papel oncoprotetor x oncogênico relatado para o T. cruzi. The DNA Damage Response (DDR) is essential for genomic integrity and cell survival. This response involves cell cycle checkpoints and mechanisms of DNA repair. Depending on the damage type, different repair pathways are activated. Cisplatin is a drug that generates DNA adducts and interstrand crosslinks. Hydrogen peroxide (H2O2) is another compound that, in supraphysiological concentrations, damages DNA and other biomolecules. Oxidative stress causes mainly base modifications and DNA strand breaks. There are evidences that Trypanosoma cruzi, a protozoan that causes Chagas disease, interferes in different manners with the metabolism of the host cell, including DNA metabolism. In this research, we analyzed the influence of two T. cruzi’s strains, Berenice and Colombiana, in the DDR of L6 cells (rat myocytes). L6 cells were treated with two different concentrations of cisplatin and H2O2, and different biological aspects were evaluated, as viability, proliferation, morphology, DNA degradation and expression of repair and cell cycle genes. Depending on the concentration of cisplatin or H2O2, the cells reacted differently, showing distinct rates of DNA damage, considering the concentration of cisplatin or H2O2. Treatment with cisplatin showed that Berenice strain altered host damage response to DNA damage, with higher expression of some repair pathways (e.g. MMR) and lower expression of genes related to the repair of double strands breaks (DSB), resulting in DNA degradation and mortality. Cells infected with Colombiana strain, on the other hand, presented a cisplatin resistance profile, with activation of effective pathways to repair DNA adducts (as NER). The results also indicated that infection by Colombiana archetype stimulates an alternative repair via retrotransposon LINE-1. These cells also presented a senescent profile, similar to non-infected cells. Hydrogen Peroxide treatment showed that T. cruzi infection may act as a stressor or protective element of host DNA, depending on the strain and on the H2O2 concentration. Differences were also detected differences in gene expression in cells infected with Berenice strain, which reduced the DNA damage response intensity (e.g. BER and HR), in the treatment with 0,8mM of H2O2. Infection with T. cruzi Colombiana did not activate multiple pathways in response to H2O2 (NER and MMR). These cells did not show signicant differences in mortality, indicating that maybe the parasite influences the host DNA to repair itself directly. Our results will contribute to a better understanding of the parasite-host relationshp and can not only clarify Chagas disease pathology, but also help to understand the dubious role of T. cruzi in response to cancer.