Biocompatible Magic Sized Quantum Dots: Luminescent Markers and Probes

Nanoscience and nanobiotechnology have aroused great academic and technological interest. Works relating biomaterials at the nanoscale can reach new biotechnologies and help in the development and use of tools for bioimage and diagnosis applications. In this work we demonstrated the advantages of magic sized quantum dots as luminescent markers and probes to bioimage applications. The visualization of MSQDs bioconjugated with biological probes in cells were performed at periods greater than 2 h, and visualization with no commercial dye would not be possible. Therefore, we demonstrated that theses biocompatible nanocrystals are luminescent markers and probes to diagnosis

Biocompatibility of Doped Semiconductors Nanocrystals and Nanocomposites

Exposure of humans and environment to nanocrystals are inevitable, and nanotoxicological analyses are a requirement. The wide variety of nanocrystals with different applications is increasing, and characterization of their effects after exposure includes their potential toxicity and uses. This review summarizes the characterization of doped nanocrystals and nanocomposites, Ca-doped ZnO, Ag- and Eu-doped ZnO and Ni-doped ZnO NCs, their biocompatibility and applications. This review uncovers how these nanocrystals present desirable biocompatible properties, which can be useful as antitumoral and antimicrobial inducing agents, which differ markedly from toxic properties observed in other general nanocrystals

Antitumor and antiangiogenic effect of a phospholipase A2 from Bothrops jararacussu venom (BthTX-II) and inhibition of Epithelium-Mesenchyme Transition (TMS) under breast tumor cells

Phospholipases A2 represent an enzyme superfamily widely distributed in living organisms, with a broad spectrum of pharmacological activities and therapeutic potential. In this context, the present paper reports firsthand the antitumor, antimetastatic and antiangiogenic effects of BthTX-II, a PLA2 Asp49 isolated from Bothrops jararacussu venom, on breast cancer strains. BthTX-II-induced cell death by modulating different genes of the intrinsic (BAD, BAX, BCL2, and BCL2L1) and extrinsic (TNF, TNFRS10B, TNFRSF1A and Caspase 8) signaling pathways. PLA2 also inhibited cell proliferation, adhesion, migration, cell invasion and 3D growth in matrigel, reducing the aggressiveness of metastatic breast cancer cells by negatively modulating the BRCA1 and BRCA2 tumor suppression genes, as well as the proangiogenic factor. ANGPT1. Also, BthTX-II reduced the expression of vimentin, TWIST1, CK-5 and was able to increase the protein expression of E-cadherin and its gene (CDH-1), leading the metastatic breast cancer cell to assume a characteristic epithelial phenotype with less invasive properties. Interestingly, BthTX-II inhibited human endothelial cell adhesion, invasion, and migration and blocked angiogenesis by decreasing the formation of new vessels in HUVEC cells (in vitro) and the formation of cell extensions in an ex vivo aortic fragment model, as well as reducing production of endothelial growth factor (VEGF). Besides, it demonstrated action on growth in co-culture, whose action was the reduction of tumor mass in vivo in the membrane assay (CAM) in chicken embryos. Taken together, the results show that BthTX-II has significant antitumor and antiangiogenic activity, enabling its use as a potential prototype for the development of antitumor drugs in triple-negative breast cancer therapy.Tese (Doutorado)As fosfolipases A2 representam uma superfamília de enzimas amplamente distribuída nos organismos vivos, com um amplo espectro de atividades farmacológicas e potencial terapêutico. Nesse contexto, o presente trabalho relata em primeira mão os efeitos antitumorais, antimetastáticos e antiangiogênicos da BthTX-II, uma PLA2 Asp49 isolada da peçonha de Bothrops jararacussu, sobre linhagens de câncer de mama. A BthTX-II induziu morte celular através da modulação de diferentes genes das vias de sinalização intrínseca (BAD, BAX, BCL2 e BCL2L1) e extrínseca (TNF, TNFRS10B, TNFRSF1A e Caspase 8) da apoptose. A PLA2 também inibiu a proliferação celular, adesão, migração, invasão celular e crescimento 3D em matrigel, reduzindo a agressividade das células câncer de mama metastático, através da modulação negativa dos genes de supressão tumoral BRCA1 e BRCA2, bem como do fator pró-angiogênico ANGPT1. Além disso, a BthTX-II reduziu a expressão de vimentina, TWIST1, CK-5 e foi capaz aumentar a expressão proteica de E-caderina e também do seu gene (CDH-1), levando a célula câncer de mama metastático a assumir um fenótipo característico epitelial, com propriedades menos invasivas. Interessantemente, a BthTX-II inibiu a adesão, invasão e migração de células endoteliais humanas e bloqueou a angiogênese por diminuir a formação de novos vasos em células HUVEC (in vitro) e formação de prolongamentos celulares em modelo ex vivo de fragmento de aorta, além de reduzir a produção de fator de crescimento endotelial (VEGF). Em adição demonstrou ação sobre crescimento em co-cultura, cuja ação foi a redução da massa tumoral in vivo no ensaio de membrana (CAM) em embriões de galinhas. Analisados em conjunto, os resultados demonstram que a BthTX-II apresenta significante atividade antitumoral e antiangiogênica, possibilitando o seu uso como um protótipo potencial para o desenvolvimento de fármacos antitumorais na terapia contra o câncer de mama triplo negativo

Morte de células de adenocarcinoma de mama humano por BnSP-6, uma fosfolipase A2 Lys-49 homóloga da peçonha de Bothrops pauloensis

CHAPTER II: PLA2s from snake venom display various biological activities and currently, has been reported that have antitumor and antiangiogenic properties. This work shows the effects of phospholipase A2 (BnSP-6), a Lys 49 isolated from Bothrops pauloensis venom, on human breast cancer MDA-MB-231cell. PLA2 BnSP-6 caused a dose-dependent cytotoxicity at concentrations of 12.5 - 100 μg/mL and inhibited the cell adhesion. Interestingly the cytotoxic potential of BnSP-6 was significantly lower against MCF10A, a non-tumorigenic breast epithelial cell line, suggesting that the PLA2 presented a possible preference for targets in cancer cells. Analysis of cell death showed that BnSP-6 stimulated the autophagy process on MDA-MB-231 cell, as evidenced by labeling of autophagic vacuoles. Moreover, apoptosis/necrosis assays showed that MDA-MB-231 cell cultured in presence of BnSP-6 (10 and 50μg/mL) presented induction of both early and late apoptosis. Apoptosis of MDA-MB-231 cells was also confirmed by up regulation of different genes related to apoptosis pathway, such as TNF, TNFRSF10B, TNFRSF1A and CASP8 and decrease of anti-apoptotic genes expression (BCL2 and BCL2L). In addition, BnSP-6 caused remarkable gene expression increased of tumors suppressor BRCA2 and TP53. Finally, BnSP-6 induced down-regulation of Angiopoetin 1 gene (potent pro-angiogenic factor) and inhibited adhesion and migration of MDA-MB-231 cells suggesting pharmaceutical applications to this PLA2 as an antiangiogenic and anti-metastatic therapeutic agent. Taken together our results showed that PLA2 BnSP-6 presented antitumor potential that can be exploited as prototype for the design of new anticancer therapies.Fundação de Amparo a Pesquisa do Estado de Minas GeraisMestre em Genética e BioquímicaCAPÍTULO II: PLA2s isoladas da peçonha de serpentes exibem várias atividades biológicas e atualmente, tem sido relacionadas com várias propriedades antitumorais e anti-angiogênicas. Neste trabalho mostramos os efeitos da fosfolipase A2 (BnSP-6), uma Lys-49, isolada da peçonha de Bothrops pauloensis, em células MDA-MB-231 de câncer da mama humano. A PLA2-BnSP-6, apresentou citotoxicidade dose-dependente nas concentrações de 12,5 a 100 mg/mL e inibiu a adesão celular. Interessantemente, o potencial citotóxico da BnSP-6 foi relativamente menor em MCF10A, uma linhagem de célula epitelial mamária normal, sugerindo uma possível preferência da PLA2 por alvos em células tumorais. Nas análises de morte celular a BnSP-6 estimulou o processo de autofagia em células MDA-MB-231, como observado pela marcação de vacúolos autofágicos. Em ensaios de apoptose/necrose as células MDA-MB-231 cultivadas na presença de BnSP-6 (10 e 50 ug/mL) apresentaram indução tanto na apoptose inicial quanto tardia. A apoptose também foi confirmada em células MDA-MB-231 pelo aumento na expressão de vários genes relacionados às vias de apoptose, tais como TNF, TNFRSF10B, TNFRSF1A e CASP8 e também pela diminuição na expressão de genes anti-apoptóticos (BCL2 e BCL2L). Além da influencia na expressão de genes de vias apoptóticas, a BnSP-6 também causou notável aumento na expressão dos genes de supressão tumoral BRCA2 e TP53. Finalmente, a BnSP-6 induziu redução na expressão do gene de Angiopoietina-1 (fator pró-angiogênico), bem como na adesão e migração de células MDA-MB-231, sugerindo aplicações terapêuticas para esta PLA2 como agente anti-angiogênico e anti-metastático. Em conjunto, nossos resultados confirmam que a PLA2-BnSP-6 apresenta potencial antitumoral, podendo ser explorada como protótipo para o desenvolvimento de novas terapias anticâncer

A New Approach to Inhibiting Triple-Negative Breast Cancer: In Vitro, Ex Vivo and In Vivo Antiangiogenic Effect of BthTx-II, a PLA2-Asp-49 from Bothrops jararacussu Venom

Phospholipases A2 (PLA2) represent a superfamily of enzymes widely distributed in living organisms, with a broad spectrum of pharmacological activities and therapeutic potential. Anti-angiogenic strategies have become one of the main tools in fighting cancer. In this sense, the present work reports the inhibition of tumor angiogenesis induced by Asp-49 BthTX-II using in vitro, ex vivo and in vivo approaches. We demonstrate that BthTx-II inhibited cell adhesion, proliferation, and migration of human umbilical vein endothelial cells (HUVEC), as well as caused a reduction in the levels of endothelial growth factor (VEGF) during in vitro angiogenesis assays. BthTx-II was also able to inhibit the sprouting angiogenic process, by the ex vivo germination assay of the aortic ring; in addition, this toxin inhibited the migration and proliferation of HUVEC in co-culture with triple-negative breast cancer cells (e.g., MDA-MB-231 cells). Finally, in vivo tumor suppression and anti-angiogenic activities were analyzed using MDA-MB-231 cells with Matrigel injected into the chorioallantoic membrane of chicken embryo (CAM) for 7 days treatment with BthTx-II, showing a considerable reduction in vessel caliber, on the size and weight of tumors. Together, these results suggest an important antiangiogenic and antitumor role for BthTx-II, as a potential prototype for the development of new tools and antitumor drugs in cancer therapy

A New Approach to Inhibiting Triple-Negative Breast Cancer: In Vitro, Ex Vivo and In Vivo Antiangiogenic Effect of BthTx-II, a PLA₂-Asp-49 from <i>Bothrops jararacussu</i> Venom

Phospholipases A2 (PLA2) represent a superfamily of enzymes widely distributed in living organisms, with a broad spectrum of pharmacological activities and therapeutic potential. Anti-angiogenic strategies have become one of the main tools in fighting cancer. In this sense, the present work reports the inhibition of tumor angiogenesis induced by Asp-49 BthTX-II using in vitro, ex vivo and in vivo approaches. We demonstrate that BthTx-II inhibited cell adhesion, proliferation, and migration of human umbilical vein endothelial cells (HUVEC), as well as caused a reduction in the levels of endothelial growth factor (VEGF) during in vitro angiogenesis assays. BthTx-II was also able to inhibit the sprouting angiogenic process, by the ex vivo germination assay of the aortic ring; in addition, this toxin inhibited the migration and proliferation of HUVEC in co-culture with triple-negative breast cancer cells (e.g., MDA-MB-231 cells). Finally, in vivo tumor suppression and anti-angiogenic activities were analyzed using MDA-MB-231 cells with Matrigel injected into the chorioallantoic membrane of chicken embryo (CAM) for 7 days treatment with BthTx-II, showing a considerable reduction in vessel caliber, on the size and weight of tumors. Together, these results suggest an important antiangiogenic and antitumor role for BthTx-II, as a potential prototype for the development of new tools and antitumor drugs in cancer therapy

Shedding Lights on Crude Venom from Solitary Foraging Predatory Ant <i>Ectatomma opaciventre</i>: Initial Toxinological Investigation

Some species of primitive predatory ants, despite living in a colony, exercise their hunting collection strategy individually; their venom is painful, paralyzing, digestive, and lethal for their prey, yet the toxins responsible for these effects are poorly known. Ectatomma opaciventre is a previously unrecorded solitary hunting ant from the Brazilian Cerrado. To overcome this hindrance, the present study performed the in vitro enzymatic, biochemical, and biological activities of E. opaciventre to better understand the properties of this venom. Its venom showed several proteins with masses ranging from 1–116 kDa, highlighting the complexity of this venom. Compounds with high enzymatic activity were described, elucidating different enzyme classes present in the venom, with the presence of the first L-amino acid oxidase in Hymenoptera venoms being reported. Its crude venom contributes to a state of blood incoagulability, acting on primary hemostasis, inhibiting collagen-induced platelet aggregation, and operating on the fibrinolysis of loose red clots. Furthermore, the E. opaciventre venom preferentially induced cytotoxic effects on lung cancer cell lines and three different species of Leishmania. These data shed a comprehensive portrait of enzymatic components, biochemical and biological effects in vitro, opening perspectives for bio-pharmacological application of E. opaciventre venom molecules