The Roles of ROS in Cancer Heterogeneity and Therapy.

Cancer comprises a group of heterogeneous diseases encompassing high rates of morbidity and mortality. Heterogeneity, which is a hallmark of cancer, is one of the main factors related to resistance to chemotherapeutic agents leading to poor prognosis. Heterogeneity is profoundly affected by increasing levels of ROS. Under low concentrations, ROS may function as signaling molecules favoring tumorigenesis and heterogeneity, while under high ROS concentrations, these species may work as cancer modulators due to their deleterious, genotoxic or even proapoptotic effect on cancer cells. This double-edged sword effect represented by ROS relies on their ability to cause genetic and epigenetic modifications in DNA structure. Antitumor therapeutic approaches may use molecules that prevent the ROS formation precluding carcinogenesis or use chemical agents that promote a sudden increase of ROS causing considerable oxidative stress inside tumor mass. Therefore, herein, we review what ROS are and how they are produced in normal and in cancer cells while providing an argumentative discussion about their role in cancer pathophysiology. We also describe the various sources of ROS in cancer and their role in tumor heterogeneity. Further, we also discuss some therapeutic strategies from the current landscape of cancer heterogeneity, ROS modulation, or ROS production.

Evaluation of cytotoxic effect of the combination of a pyridinyl carboxamide derivative and oxaliplatin on NCI-H1299 human non-small cell lung carcinoma cells.

Even with all improvements in both diagnostic and therapeutic techniques, lung cancer remains as the most lethal and prevalent cancer in the world. Therefore, new therapeutic drugs and new strategies of drug combination are necessary to provide treatments that are more efficient. Currently, standard therapy regimen for lung cancer includes platinum drugs, such as cisplatin, oxaliplatin, and carboplatin. Besides of the better toxicity profile of oxaliplatin when compared with cisplatin, peripheral neuropathy remains as a limitation of oxaliplatin dose. This study presents LabMol-12, a new pyridinyl carboxamide derivative with antileishmanial and antichagasic activity, as a new hit for lung cancer treatment, which induces apoptosis dependent of caspases in NCI-H1299 lung cancer cells both in monolayer and 3D culture. Moreover, LabMol-12 allows a reduction of oxaliplatin dose when they are combined, thereby, it is a relevant strategy for reducing the side effects of oxaliplatin with the same response. Molecular modeling studies corroborated the biological findings and suggested that the combined therapy can provide a better therapeutically profile effects against NSCLC. All these findings support the fact that the combination of oxaliplatin and LabMol-12 is a promising drug combination for lung cancer.

Synergistic anti-tumor effects of the combination of a benzofuroxan derivate and sorafenib on NCI-H460 human large cell lung carcinoma cells.

Lung cancer is the most frequent and lethal human cancer in the world. Because is still an unsolved health issue, new compounds or therapeutic strategies are urgently needed. Furoxans are presented as potentials candidates for lung cancer treatment. Accordingly, we evaluated the efficacy of a benzofuroxan derivative, BFD-22, alone and combined with sorafenib against NCI-H460 cell line. We showed that BFD-22 has cytotoxic effects on the NCI-H460 cells. Importantly, the Combination Index (CI) evaluation revels that BFD-22 combined with sorafenib has a stronger cytotoxic effect. In addition, the combination induces apoptosis through extrinsic pathway, leading to TRAIL-R1/DR4-triggered apoptosis. Furthermore, BFD-22 combined with sorafenib increases ROS production and simultaneously reduces perlecan expression in the NCI-H460 cells. In accordance, tumor cells were arrested in the S-phase, and these anti-proliferative effects also inhibit cell migration. This is the first study reporting an advantage of BFD-22 combined with sorafenib as a new therapeutic strategy in the fight against lung cancer.

5-Nitro-2-furfuriliden derivatives as potential anti-Trypanosoma cruzi agents: design, synthesis, bioactivity evaluation, cytotoxicity and exploratory data analysis.

The anti-Trypanosoma cruzi activity of 5-nitro-2-furfuriliden derivatives as well as the cytotoxicity of these compounds on J774 macrophages cell line and FN1 human fibroblast cells were investigated in this study. The most active compounds of series I and II were 4-butyl-[N'-(5-nitrofuran-2-yl) methylene] benzidrazide (3g; IC50=1.05µM±0.07) and 3-acetyl-5-(4-butylphenyl)-2-(5-nitrofuran-2-yl)-2,3-dihydro,1,3,4-oxadiazole (4g; IC50=8.27µM±0.42), respectively. Also, compound 3g was more active than the standard drugs, benznidazole (IC50=22.69µM±1.96) and nifurtimox (IC50=3.78µM±0.10). Regarding the cytotoxicity assay, the 3g compound presented IC50 value of 28.05µM (SI=26.71) against J774 cells. For the FN1 fibroblast assay, 3g showed IC50 value of 98µM (SI=93.33). On the other hand, compound 4g presented a cytotoxicity value on J774 cells higher than 400µM (SI >48), and for the FN1 cells its IC50 value was 186µM (SI=22.49). Moreover, an exploratory data analysis, which comprises hierarchical cluster (HCA) and principal component analysis (PCA), was carried out and the findings were complementary. The molecular properties that most influenced the compounds' grouping were ClogP and total dipole moment, pointing out the need of a lipophilic/hydrophilic balance in the designing of novel potential anti-T. cruzi molecules.

Ligand-based design, synthesis, and experimental evaluation of novel benzofuroxan derivatives as anti-Trypanosoma cruzi agents.

A set of substituted-[N'-(benzofuroxan-5-yl)methylene]benzohydrazides (4a-t), previously designed and synthesized, was experimentally assayed against Trypanosoma cruzi, the etiological agent of Chagas' disease, one of the most neglected tropical diseases. Exploratory data analysis, Hansch approach and VolSurf formalism were applied to aid the ligand-based design of novel anti-T. cruzi agents. The best 2D-QSAR model showed suitable statistical measures [n = 18; s = 0.11; F = 42.19; R(2) = 0.90 and Q(2) = 0.77 (SDEP = 0.15)], and according to the optimum 3D-QSAR model [R(2) = 0.98, Q(2) = 0.93 (SDEP = 0.08)], three latent variables explained 62% of the total variance from original data. Steric and hydrophobic properties were pointed out as the key for biological activity. Based upon the findings, six novel benzofuroxan derivatives (4u-z) were designed, synthesized, and in vitro assayed to perform the QSAR external prediction. Then, the predictability for the both models, 2D-QSAR (Rpred(2) = 0.91) and 3D-QSAR (Rpred(2) = 0.77), was experimentally validated, and compound 4u was identified as the most active anti-T. cruzi hit (IC50 = 3.04 µM).

Synthesis, molecular modeling and preliminary biological evaluation of a set of 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazole as potential antibacterial, anti-Trypanosoma cruzi and antifungal agents.

A series of 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazole derivatives was synthesized and their activity screened in vitro against Staphylococcus aureus, Trypanosoma cruzi, and Candida albicans. The bioactivity was expressed as minimum inhibitory concentration (MIC) for S. aureus strains, and as fifty-percent inhibitory concentration (IC(50)) of parasite population growth for T. cruzi. A molecular modeling approach was performed to establish qualitative relationships regarding the biological data and the compounds' physicochemical properties. The 5-(4-OC(4)H(9)Ph, 5l), and 5-(4-CO(2)CH(3)Ph, 5o) derivatives were the most active compounds for S. aureus ATCC 25923 (MIC=1.95-1.25 µg/mL) and T. cruzi (IC(50)=7.91 µM), respectively. Also, a preliminary evaluation against C. albicans involving some compounds was performed and the 5-(4-CH(3)Ph, 5e) derivative was the most active compound (MIC=3.28-2.95 µg/mL). In this preliminary study, all synthesized 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazole derivatives were active against all microorganisms tested.

Novel benzofuroxan derivatives against multidrug-resistant Staphylococcus aureus strains: design using Topliss' decision tree, synthesis and biological assay.

The aim of this study was the design of a set of benzofuroxan derivatives as antimicrobial agents exploring the physicochemical properties of the related substituents. Topliss' decision tree approach was applied to select the substituent groups. Hierarchical cluster analysis was also performed to emphasize natural clusters and patterns. The compounds were obtained using two synthetic approaches for reducing the synthetic steps as well as improving the yield. The minimal inhibitory concentration method was employed to evaluate the activity against multidrug-resistant Staphylococcus aureus strains. The most active compound was 4-nitro-3-(trifluoromethyl)[N'-(benzofuroxan-5-yl)methylene]benzhydrazide (MIC range 12.7-11.4 µg/mL), pointing out that the antimicrobial activity was indeed influenced by the hydrophobic and electron-withdrawing property of the substituent groups 3-CF(3) and 4-NO(2), respectively.

Planejamento, desenvolvimento e estudos de QSAR de derivados benzofuroxânicos com atividade frente Staphylococcus aureus e Trypanosoma cruzi / Design, development and QSAR studies of benzofuroxan derivatives with activity against Staphylococcus aureus and Trypanosoma cruzi

A modificação molecular de fármacos do arsenal terapêutico é estratégia promissora no planejamento e desenvolvimento de novas entidades químicas que possam apresentar características pertinentes deste fármaco, e suprimir suas características indesejáveis. Desta forma, na busca por novos compostos com atividade antimicrobiana, uma série de vinte [N'-(benzofuroxan-5-il)metileno]benzidrazidas substituídas, análogas funcionais da nifuroxazida (Passifuril®), foram sintetizadas e sua atividade biológica foi testada frente a cepas padrão e multirresistentes (MRSA e VISA) de Staphylococcus aureus, e frente a formas epimatigotas de Trypanosoma cruzi, agente causal da Doença de Chagas. A escolha dos grupos substituintes foi baseada em suas propriedades físico-químicas, tais como efeito eletrônico e hidrofobicidade, empregando o Diagrama de Craig. Os compostos foram obtidos por rota sintética descrita em literatura, assim como por rotas alternativas a fim de otimizar a metodologia tradicional e melhorar o rendimento dos produtos finais. Todos os compostos foram identificados e apresentam estrutura química inédita. A atividade dos vinte compostos frente S. aureus foi avaliada pelo método de determinação da concentração inibitória mínima (CIM); destes, dezesseis apresentaram os mesmos intervalos de CIM frente as cepas padrão e multirresistentes. O composto dissubstituído 3-CF3,4-NO2 (7t), apresentou a maior atividade com valores de CIM entre 12,7 - 11,4 µg/mL. A avaliação da atividade anti-T. cruzi também foi investigada, e na fase log de crescimento parasitário os compostos substituídos 4-H (7a), 4-CF3 (7n), 3,4-Cl2 (7s), 3-CF3,4-NO2 (7t) demonstraram os melhores resultados. O benznidazol, único fármaco utilizado no tratamento da Doença de Chagas, foi utilizado como referência nas mesmas concentrações. Os compostos que apresentaram melhores atividades nos ensaios realizados na fase estacionária de crescimento foram os compostos substituídos 4-I (7q) e 4-Br (7o) com valores de %IC50 de 6,11 µM e 7,38 µM, respectivamente. A influência das propriedades físico-químicas dos grupos substituintes em ambas as atividades foi observada e, a fim de avaliar quantitativamente suas contribuições para a bioatividade, estudos de QSAR-2D e QSAR-3D foram desenvolvidos, auxiliando assim na predição de novas estruturas com propriedades farmacológicas otimizadas, uma vez que os resultados obtidos indicam o forte potencial destes compostos na identificação de novos candidatos a fármaco antimicrobiano

Molecular modification of drugs from the therapeutic arsenal is a promising strategy for the design and development of new chemical entities that can demonstrate the relevant properties of this drug, and suppressing its undesirable properties. For the research of new leads with potential antimicrobial activity, a new series of twenty substituted [N´-(benzofuroxan-5-yl)methylene]benzohydrazides, nifuroxazide's (Passifuril®) functional analogs, was synthesized and tested against standard and multidrug-resistant Staphylococcus aureus (MRSA and VISA) strains and against epimastigote form of Trypanosoma cruzi, the etiological agent of Chagas' Disease. The selection of the substituent groups was based on their physicochemical properties, such as hydrophobicity and electronic effects, employing Craig's diagram. The designed compounds were obtained by synthetic route described in the literature, as well as by an alternative route, in order to optimize the traditional methodology and also to improve the final compounds yields. All compounds were identified as unpublished chemical structures. Bacterial activity of the twenty compounds against S. aureus was performed by minimal inhibitory concentration method (MIC), and sixteen of them exhibited similar bacteriostatic activity against standard and multidrug-resistant strains. The most active compound was the 3-CF3,4-NO2 disubstituted derivative (7t), which presented a MIC value from 12.7 to 11.4 µg/mL. Anti-T. cruzi activity was also investigated. The substituted compounds 4-H (7a), 4-CF3 (7n), 3,4-Cl2 (7s), 3-CF3,4-NO2 (7t) showed better results at logarithmic growth phase. Benznidazole, that is the only drug available to threat Chagas' disease, was used as a reference drug at the same concentrations of the compounds studied. The most effective substituded compounds were the 4-I (7q) and 4-Br (7o) substituted derivatives having %IC50 values of 6.11 µM and 7.38 µM, respectively, at stationary growth phase. The influence of the substituent's physicochemical properties on in vitro activities was observed, and, in order to establish quantitatively their contributions to bioactivity, 2D-QSAR and 3D-QSAR studies were developed, assisting in the prediction of new leads with improved pharmacological properties, since the results showed benzofuroxan derivatives as potential leads for identifying new drug candidates

Molecular modeling studies and in vitro bioactivity evaluation of a set of novel 5-nitro-heterocyclic derivatives as anti-T. cruzi agents.

In this study, in vitro anti-T. cruzi activity assays of nifuroxazide (NX) analogues, such as 5-nitro-2-furfuryliden and 5-nitro-2-theniliden derivatives, were performed. A molecular modeling approach was also carried out to relate the lipophilicity potential (LP) property and biological activity data. The majority of the NX derivatives showed increased anti-T. cruzi activity in comparison to the reference drug, benznidazole (BZN). Additionally, the 5-nitro-2-furfuryliden derivatives presented better pharmacological profile than the 5-nitro-2-theniliden analogues. The LP maps and corresponding ClogP values indicate that there is an optimum lipophilicity value, which must be observed in the design of new potential anti-T. cruzi agents.

Design, synthesis, antimicrobial activity and molecular modeling studies of novel benzofuroxan derivatives against Staphylococcus aureus.

Molecular modification is a quite promising strategy in the design and development of drug analogs with better bioavailability, higher intrinsic activity and less toxicity. In the search of new leads with potential antimicrobial activity, a new series of 14 4-substituted [N'-(benzofuroxan-5-yl)methylene]benzohydrazides, nifuroxazide derivatives, were synthesized and tested against standard and multidrug-resistant Staphylococcus aureus strains. The selection of the substituent groups was based on physicochemical properties, such as hydrophobicity and electronic effect. These properties were also evaluated through the lipophilic and electrostatic potential maps, respectively, considering the compounds with better biological profile. Twelve compounds exhibited similar bacteriostatic activity against standard and multidrug-resistant strains. The most active compound was the 4-CF(3) substituted derivative, which presented a minimum inhibitory concentration (MIC) value of 14.6-13.1 microg/mL, and a ClogP value of 1.87. The results highlight the benzofuroxan derivatives as potential leads for designing new future antimicrobial drug candidates.