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1.
Sci Total Environ ; 946: 174240, 2024 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-38925383

RESUMO

Medium-scale pig production systems, which make up 30 % of Mexico's pig farms, face two key obstacles impacting their economic and financial performance. The first is the absence of a sales plan based on pigs' weight, which negatively affects both profitability and resource management. The second obstacle is inadequate waste management, which hampers efforts to mitigate environmental impacts generated by pig farms. Based on this criterion, this study aims to determine technical and economic optimum levels of a medium-scale pig farm and evaluate its associated environmental impacts. Based on the last farm sale weight (116.3 kg - base scenario), technical and economic optimum levels were estimated using a production function, resulting in a technical optimum of 155 kg and an economic optimum of 127 kg. An environmental assessment of the pig fattening process was carried out following the principles of the Life Cycle Analysis methodological framework. Using a cradle-to-farm gate perspective, and establishing 1 kg of live-weight pig as the functional unit. The results indicated that production at maximum weight level (155 kg), increased environmental impacts by 60 % to 75 % compared to the base scenario. In contrast, at the maximum economic benefit level (127 kg), environmental impacts increased by 5 % to 10 %. Feed production represented the largest contribution (over 74 %) in six impact categories. The results provide valuable information for medium-scale pig farms to mitigate the environmental burdens associated with the optimal production weight and to direct efforts towards achieving future economic and environmental efficiency.


Assuntos
Criação de Animais Domésticos , Meio Ambiente , Animais , México , Criação de Animais Domésticos/métodos , Suínos , Fazendas
2.
Sci Rep ; 14(1): 14919, 2024 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-38942904

RESUMO

Helminth infections lead to an overdispersion of the parasites in humans as well as in animals. We asked whether early immune responses against migrating Ascaris larvae are responsible for the unequal distribution of worms in natural host populations and thus investigated a susceptible versus a resistant mouse strain. In mice, the roundworm larvae develop until the lung stage and thus early anti-Ascaris immune responses against the migrating larvae in the liver and lung can be deciphered. Our data show that susceptible C57BL/6 mice respond to Ascaris larval migration significantly stronger compared to resistant CBA mice and the anti-parasite reactivity is associated with pathology. Increased eosinophil recruitment was detected in the liver and lungs, but also in the spleen and peritoneal cavity of susceptible mice on day 8 post infection compared to resistant mice. In serum, eosinophil peroxidase levels were significantly higher only in the susceptible mice, indicating functional activity of the recruited eosinophils. This effect was associated with an increased IL-5/IL-13 production by innate lymphoid cells and CD4+ T cells and a pronounced type 2 macrophage polarization in the lungs of susceptible mice. Furthermore, a comparison of wildtype BALB/c and eosinophil-deficient dblGATA-1 BALB/c mice showed that eosinophils were not essential for the early control of migrating Ascaris larvae. In conclusion, in primary infection, a strong local and systemic type 2 immune response during hepato-tracheal helminth larval migration is associated with pathology rather than protection.


Assuntos
Ascaríase , Larva , Pulmão , Camundongos Endogâmicos BALB C , Células Th2 , Animais , Ascaríase/imunologia , Ascaríase/parasitologia , Larva/imunologia , Camundongos , Células Th2/imunologia , Pulmão/parasitologia , Pulmão/imunologia , Pulmão/patologia , Ascaris/imunologia , Eosinófilos/imunologia , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Fígado/parasitologia , Fígado/imunologia , Fígado/patologia , Feminino
3.
Front Immunol ; 15: 1396446, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38799456

RESUMO

Ascaris spp. undergo extensive migration within the body before establishing patent infections in the small intestinal tract of humans and pigs. However, whether larval migration is critical for inducing efficient type 2 responses remains poorly understood. Therefore, we investigated systemic versus local adaptive immune responses along the hepato-tracheal migration of Ascaris suum during primary, single infections in conventionally raised pigs. Neither the initial invasion of gut tissue nor migration through the liver resulted in discernable Th2 cell responses. In contrast, lung-stage larvae elicited a Th2-biased pulmonary response, which declined after the larvae had left the lungs. In the small intestine, we observed an accumulation of Th2 cells upon the arrival of fourth-stage larvae (L4) to the small intestinal lumen. In parallel, we noticed robust and increasing Th1 responses in circulation, migration-affected organs, and draining lymph nodes. Phenotypic analysis of CD4+ T cells specifically recognizing A. suum antigens in the circulation and lung tissue of infected pigs confirmed that the majority of Ascaris-specific T cells produced IL-4 (Th2) and, to a much lesser extent, IL-4/IFN-g (Th2/1 hybrids) or IFN-g alone (Th1). These data demonstrate that lung-stage but not the early liver-stage larvae lead to a locally restricted Th2 response. Significant Th2 cell accumulation in the small intestine occurs only when L4 complete the body migration. In addition, Th2 immunity seems to be hampered by the concurrent, nonspecific Th1 bias in growing pigs. Together, the late onset of Th2 immunity at the site of infection and the Th1-biased systemic immunity likely enable the establishment of intestinal infections by sufficiently large L4 stages and pre-adult worms, some of which resist expulsion mechanisms.


Assuntos
Ascaríase , Ascaris suum , Células Th1 , Células Th2 , Animais , Ascaris suum/imunologia , Ascaríase/imunologia , Ascaríase/parasitologia , Células Th2/imunologia , Suínos , Células Th1/imunologia , Doenças dos Suínos/imunologia , Doenças dos Suínos/parasitologia , Pulmão/imunologia , Pulmão/parasitologia , Larva/imunologia , Citocinas/metabolismo
4.
Arch Cardiol Mex ; 94(3): 373-380, 2024 03 13.
Artigo em Espanhol | MEDLINE | ID: mdl-38478992

RESUMO

Aneurysms are clinical entities that can develop and affect human aorta; and although in most cases they have an asymptomatic course, these pathological dilatations can lead to a lethal outcome when rupture occurs, thus the establishment of predictors is crucial for death prevention. Essential events that take place in the vessel wall have been identified and described, such as inflammation, proteolysis, smooth muscle cell apoptosis, angiogenesis, and vascular remodeling. Porcine and ovine models have been useful for the development and evaluation of endovascular devices of the aorta. However, since the worldwide introduction and adoption of these minimally invasive techniques for aneurysm repair, there is lesser availability of diseased aortic tissue for molecular, cellular, and histopathological analysis, therefore over the last three decades it has been proposed various small species models that have allowed the focal induction of these lesions for the study of physiopathological mechanisms and possible useful biomarkers as diagnostic and therapeutic targets. The present review article presents and discusses the animal models available as their applications, characteristics, advantages, and limitations for the development of preclinical studies, and their importance in the comprehension of this pathology in humans.


Los aneurismas son una de las entidades clínicas que pueden desarrollarse y afectar la aorta humana. Aunque en la mayoría de los casos tienen un carácter asintomático, estas dilataciones patológicas pueden resultar letales cuando se presentan con ruptura, por lo que el reconocimiento de factores predictores de esta complicación es crucial para evitar muertes. Fisiopatológicamente se han identificado eventos esenciales que ocurren en la pared del vaso, como inflamación, proteólisis, apoptosis del músculo liso, angiogénesis y remodelación. Las grandes especies como porcinos y ovinos han sido de utilidad para el desarrollo y evaluación del desempeño de dispositivos endovasculares en la aorta, así como la remodelación; con el advenimiento y disposición de estas técnicas mínimamente invasivas para su reparación existe una menor disponibilidad de tejido aórtico para el análisis molecular, celular e histopatológico, por lo que en las últimas tres décadas se han propuesto e introducido distintos modelos que han permitido, mediante la inducción focal de estas lesiones, el estudio de los mecanismos fisiopatológicos y posibles biomarcadores de utilidad como dianas diagnósticas y terapéuticas. El presente artículo de revisión aborda tipos de modelos animales disponibles, así como sus aplicaciones, consideraciones, ventajas y limitaciones para el desarrollo de estudios preclínicos y su importancia en el entendimiento de esta patología en la especie humana.


Assuntos
Aneurisma da Aorta Abdominal , Aneurisma da Aorta Torácica , Modelos Animais de Doenças , Animais , Aneurisma da Aorta Abdominal/patologia , Aneurisma da Aorta Torácica/cirurgia , Humanos
6.
Int J Surg Case Rep ; 117: 109509, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38490032

RESUMO

INTRODUCTION: Peritoneal dialysis is the preferred approach for kidney replacement therapy. A peritoneal-vaginal fistula is a rare complication associated with peritoneal dialysis. CASE PRESENTATION: A 69-year-old woman with a history of type two diabetes and systemic arterial hypertension for twenty years is scheduled to undergo the surgical placement of a Tenckoff catheter to begin renal replacement therapy. After having thirty dialysis sessions, she was discharged to continue therapy at home. Five days later, she observed a notable rise in vaginal discharge after peritoneal dialysis. This case report investigates the etiology, diagnosis, and management of peritoneal vaginal fistula and analyzes current medical literature. DISCUSSION: Factors associated with the formation of peritoneum-vaginal fistula include increased intra-abdominal pressure due to dialysis, anatomical predisposition, peritonitis, and malnutrition. CONCLUSIONS: Peritoneal vaginal fistula is an uncommon consequence of peritoneal dialysis. Diagnosis entails demonstrating the movement of dialysis fluid from the peritoneum to the vagina. Treatment should be customized according to the etiology of the fistula and the individual needs of each patient.

7.
Graefes Arch Clin Exp Ophthalmol ; 262(7): 2111-2120, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38376563

RESUMO

PURPOSE: To investigate the impact of anti-VEGF therapy on vascular metrics in eyes with macular edema secondary to central retinal vein occlusion (CRVO) using wider field swept-source OCT angiography (WF SS-OCTA). METHODS: We included 23 eyes with macular edema associated with non-ischemic CRVO from 22 patients treated with anti-VEGF therapy (median number of injections: 5 [2-9]). Changes in vessel density (VD), vessel skeletonized density (VSD), and foveal avascular zone (FAZ) parameters were measured using WF SS-OCTA. Visual acuity (VA) and central subfield thickness (CST) were also measured. RESULTS: Median CST decreased significantly from 369 µm (305-531) to 267 µm (243-300, p < 0.001). VD and VSD parameters in 12 × 12 mm images showed significant reductions. For instance, VSD in the whole retina decreased from a median of 13.37 (11.22-13.74) to 11.29 (9.36-12.97, p = 0.013). Additionally, a significant increase in FAZ circularity was found, suggesting improved microvascular integrity. Significant inverse correlations were found between the number of anti-VEGF injections and all VSD and VD parameters on the 12 × 12 mm images (p < 0.05). Notably, the reductions in VSD and VD on 12 × 12 mm angiograms in the deep capillary plexus (DCP) after each injection significantly correlated with increased logMAR VA (worse VA). CONCLUSION: Anti-VEGF therapy in CRVO patients not only mitigates macular edema but also alters the overall microvascular morphology and functionality as revealed by WF SS-OCTA.


Assuntos
Inibidores da Angiogênese , Angiofluoresceinografia , Fundo de Olho , Injeções Intravítreas , Ranibizumab , Oclusão da Veia Retiniana , Vasos Retinianos , Tomografia de Coerência Óptica , Fator A de Crescimento do Endotélio Vascular , Acuidade Visual , Humanos , Oclusão da Veia Retiniana/tratamento farmacológico , Oclusão da Veia Retiniana/diagnóstico , Oclusão da Veia Retiniana/fisiopatologia , Tomografia de Coerência Óptica/métodos , Angiofluoresceinografia/métodos , Inibidores da Angiogênese/uso terapêutico , Inibidores da Angiogênese/administração & dosagem , Masculino , Feminino , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Idoso , Ranibizumab/administração & dosagem , Pessoa de Meia-Idade , Vasos Retinianos/diagnóstico por imagem , Vasos Retinianos/patologia , Estudos Retrospectivos , Edema Macular/tratamento farmacológico , Edema Macular/diagnóstico , Edema Macular/etiologia , Edema Macular/fisiopatologia , Seguimentos , Bevacizumab/uso terapêutico , Bevacizumab/administração & dosagem , Receptores de Fatores de Crescimento do Endotélio Vascular/uso terapêutico , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptores de Fatores de Crescimento do Endotélio Vascular/administração & dosagem , Idoso de 80 Anos ou mais , Resultado do Tratamento
8.
Pol J Radiol ; 89: e6-e12, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38371892

RESUMO

Arterial diseases are prevalent in the general population, particularly in the elderly, and they are among the main causes of morbidity and mortality worldwide. Nuclear imaging is a useful tool in diagnosis and follow-up in different areas of medicine, and over the last 2 decades, these study modalities have become more relevant in the field of angiology and vascular surgery due to their potential benefit in the interpretation of pathophysiological mechanisms associated with the natural history and severity of diseases that affect the circulation such as vasculitis, degenerative aortic aneurysms (AA), peripheral arterial disease (PAD), and complications following reconstructive procedures such as graft infections. The literature has shown evidence of an important number of radiotracers for specific molecules involved in the activity of these entities and their utility as predictors during surveillance and possible therapeutic targets. The present narrative review aims to describe the use of nuclear medicine, imaging methods, and radiotracers that have been applied in arterial diseases, as well as the advantages and considerations, their importance in the diagnosis and follow-up of these complex groups of patients, and future perspectives.

9.
Front Vet Sci ; 10: 1270064, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38149297

RESUMO

Fasciola hepatica is distributed worldwide, causing substantial economic losses in the animal husbandry industry. Human fasciolosis is an emerging zoonosis in Andean America, Asia, and Africa. The control of the disease, both in humans and animals, is based on using anthelmintic drugs, which has resulted in increased resistance to the most effective anthelmintics, such as triclabendazole, in many countries. This, together with the concerns about drug residues in food and the environment, has increased the interest in preventive measures such as a vaccine to help control the disease in endemic areas. Despite important efforts over the past two decades and the work carried out with numerous vaccine candidates, none of them has demonstrated consistent and reproducible protection in target species. This is at least in part due to the high immunomodulation capacity of the parasite, making ineffective the host response in susceptible species such as ruminants. It is widely accepted that a deeper knowledge of the host-parasite interactions is needed for a more rational design of vaccine candidates. In recent years, the use of emerging technologies has notably increased the amount of data about these interactions. In the present study, current knowledge of host-parasite interactions and their implication in Fasciola hepatica vaccine development is reviewed.

10.
J Vitreoretin Dis ; 7(2): 165-170, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37006658

RESUMO

Purpose: To report a case of bilateral occlusive retinal vasculitis in a patient with autoimmunity. Methods: A case was analyzed and a literature review performed. Results: A 55-year-old woman with autoimmune diagnoses of Isaacs syndrome and inclusion body myositis (IBM) reported decreased vision for 3 months. A fundus examination showed peripheral intraretinal hemorrhages in the right eye and an inferotemporal subhyaloid hemorrhage with adjacent intraretinal hemorrhages and preretinal fibrosis in the left eye. Fluorescein angiography showed temporal peripheral leakage and capillary dropout in both eyes, consistent with occlusive vasculitis. Scatter laser treatment to peripheral areas of retinal nonperfusion was followed by an intravitreal bevacizumab injection. Four months later, vision had stabilized at 20/15 in both eyes and the peripheral leakage had resolved. Conclusions: This patient developed retinal vasculitis associated with the rare autoimmune neuromuscular disorders of Isaacs syndrome and IBM. An extensive workup showed the most plausible mechanism for the vasculitis was autoimmunity with a history of previously elevated antibodies levels associated with the antiphospholipid syndrome.

11.
Sensors (Basel) ; 23(6)2023 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-36991923

RESUMO

Robotic systems are a fundamental part of modern industrial development. In this regard, they are required for long periods, in repetitive processes that must comply with strict tolerance ranges. Hence, the positional accuracy of the robots is critical, since degradation of this can represent a considerable loss of resources. In recent years, prognosis and health management (PHM) methodologies, based on machine and deep learning, have been applied to robots, in order to diagnose and detect faults and identify the degradation of robot positional accuracy, using external measurement systems, such as lasers and cameras; however, their implementation is complex in industrial environments. In this respect, this paper proposes a method based on discrete wavelet transform, nonlinear indices, principal component analysis, and artificial neural networks, in order to detect a positional deviation in robot joints, by analyzing the currents of the actuators. The results show that the proposed methodology allows classification of the robot positional degradation with an accuracy of 100%, using its current signals. The early detection of robot positional degradation, allows the implementation of PHM strategies on time, and prevents losses in manufacturing processes.

12.
Eur J Immunol ; 53(5): e2250237, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36781418

RESUMO

Parasitic nematodes infect more than 1 billion people in the global south. The development of effective antihelminthic vaccines is a crucial tool for their future elimination. Protective immune responses to nematodes depend on Gata3+ Th2 cells, which can also be induced by nematode-released products. Whether these nematode products induce antigen-specific long-lived memory T cells and thereby confer protection against a challenge infection is not known yet. Hence, we set out to characterize the formation of memory Th2 cells induced by immunization with Heligmosomoides polygyrus excretory-secretory (HES) products, infection-induced versus immunization-induced recall responses to a challenge infection, and whether HES-induced memory T cells show protective properties following adoptive transfer. Our results show that 8 weeks postimmunization, HES induces long-lived functional memory Th2 cells at the site of immunization in the peritoneal cavity. Following a H. polygyrus challenge infection, HES-immunized mice display MHC-II-dependent antigen-specific Th2 cytokine responses in the gut-draining lymph nodes, comparable to those induced by a prior natural infection. Moreover, adoptive transfer of sorted memory CD4+ T cells from HES-immunized donors reduces female worm fecundity following a challenge H. polygyrus infection in recipient mice, highlighting a protective role for immunization-induced memory T cells.


Assuntos
Nematoides , Nematospiroides dubius , Infecções por Strongylida , Camundongos , Feminino , Animais , Células Th2 , Imunização , Citocinas , Vacinação , Camundongos Endogâmicos BALB C
13.
Parasite Immunol ; 45(4): e12957, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36396405

RESUMO

Antibiotic treatment can lead to elimination of both pathogenic bacteria and beneficial commensals, as well as to altered host immune responses. Here, we investigated the influence of prolonged antibiotic treatment (Abx) on effector, memory and recall Th2 immune responses during the primary infection, memory phase and secondary infection with the small intestinal nematode Heligmosomoides polygyrus. Abx treatment significantly reduced gut bacterial loads, but neither worm burdens, nor worm fecundity in primary infection were affected, only worm burdens in secondary infection were elevated in Abx treated mice. Abx mice displayed trends for elevated effector and memory Th2 responses during primary infection, but overall frequencies of Th2 cells in the siLP, PEC, mLN and in the spleen were similar between Abx treated and untreated groups. Gata3+ effector and memory Th2 cytokine responses also remained unimpaired by prolonged Abx treatment. Similarly, the energy production and defence mechanisms of the host tissue and the parasite depicted by NAD(P)H fluorescence lifetime imaging (FLIM) did not change by the prolonged use of antibiotics. We show evidence that the host Th2 response to intestinal nematodes, as well as host and parasite metabolic pathways are robust and remain unimpaired by host microbiota abrogation.


Assuntos
Coinfecção , Microbiota , Nematoides , Nematospiroides dubius , Infecções por Strongylida , Animais , Camundongos , Citocinas/metabolismo , Células Th2
14.
Case Rep Ophthalmol Med ; 2022: 5830617, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36504920

RESUMO

Purpose. To report the successful treatment of a case of presumed infectious crystalline keratopathy with repeated intrastromal antibiotic injections in a cornea graft in the setting of severe ocular graft-vs.-host-disease (GVHD). Observations. A 62-year-old man with a history of ocular GVHD and tectonic penetrating keratoplasty (PK) for corneal melt from herpes zoster keratopathy developed presumed infectious crystalline keratopathy (ICK) in the corneal graft. Given the patient's complicated ocular history, chronic immunosuppression and new cardiac comorbidities, a therapeutic PK would most likely fail. Efforts were then directed to rescue the graft with minimally invasive approaches. Two separate intrastromal injections of cefuroxime and moxifloxacin successfully treated his ICK. Conclusions and Importance. This case supports a role for repeated intrastromal antibiotic injections in patients with ICK refractory to topical antibiotic therapy, which might eliminate the need for therapeutic PK and preserve vision.

16.
In. Alvarez Sintes, Roberto. Medicina general integral. Tomo II. Principales afecciones en los contextos familiar y social. Vol. 2. Cuarta edición. La Habana, Editorial Ciencias Médicas, 4 ed; 2022. .
Monografia em Espanhol | CUMED | ID: cum-78799
17.
In. Alvarez Sintes, Roberto. Medicina general integral. Tomo II. Principales afecciones en los contextos familiar y social. Vol. 2. Cuarta edición. La Habana, Editorial Ciencias Médicas, 4 ed; 2022. , ilus, tab.
Monografia em Espanhol | CUMED | ID: cum-78797
18.
Genes (Basel) ; 12(12)2021 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-34946802

RESUMO

Sector and pericentral are two rare, regional forms of retinitis pigmentosa (RP). While usually defined as stable or only very slowly progressing, the available literature to support this claim is limited. Additionally, few studies have analyzed the spectrum of disease within a particular genotype. We identified all cases (9 patients) with an autosomal dominant Rhodopsin variant previously associated with sector RP (RHO c.316G > A, p.Gly106Arg) at our institution. Clinical histories were reviewed, and testing included visual fields, multimodal imaging, and electroretinography. Patients demonstrated a broad phenotypic spectrum that spanned regional phenotypes from sector-like to pericentral RP, as well as generalized disease. We also present evidence of significant intrafamilial variability in regional phenotypes. Finally, we present the longest-reported follow-up for a patient with RHO-associated sector-like RP, showing progression from sectoral to pericentral disease over three decades. In the absence of comorbid macular disease, the long-term prognosis for central visual acuity is good. However, we found that significant progression of RHO p.Gly106Arg disease can occur over protracted periods, with impact on peripheral vision. Longitudinal widefield imaging and periodic ERG reassessment are likely to aid in monitoring disease progression.


Assuntos
Códon/genética , Genes Dominantes/genética , Mutação/genética , Retinose Pigmentar/genética , Rodopsina/genética , Adolescente , Adulto , Feminino , Fundo de Olho , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Acuidade Visual/genética , Testes de Campo Visual/métodos , Campos Visuais/genética
19.
Int J Mol Sci ; 22(21)2021 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-34768969

RESUMO

Inherited retinal degenerations (IRDs) are a diverse group of conditions that are often characterized by the loss of photoreceptors and blindness. Recent innovations in molecular biology and genomics have allowed us to identify the causative defects behind these dystrophies and to design therapeutics that target specific mechanisms of retinal disease. Recently, the FDA approved the first in vivo gene therapy for one of these hereditary blinding conditions. Current clinical trials are exploring new therapies that could provide treatment for a growing number of retinal dystrophies. While the field has had early success with gene augmentation strategies for treating retinal disease based on loss-of-function mutations, many novel approaches hold the promise of offering therapies that span the full spectrum of causative mutations and mechanisms. Here, we provide a comprehensive review of the approaches currently in development including a discussion of retinal neuroprotection, gene therapies (gene augmentation, gene editing, RNA modification, optogenetics), and regenerative stem or precursor cell-based therapies. Our review focuses on technologies that are being developed for clinical translation or are in active clinical trials and discusses the advantages and limitations for each approach.


Assuntos
Terapia Baseada em Transplante de Células e Tecidos/tendências , Terapia de Alvo Molecular/tendências , Degeneração Retiniana/genética , Degeneração Retiniana/terapia , Edição de Genes/tendências , Terapia Genética/tendências , Humanos , Neuroproteção , Optogenética/tendências , Medicina Regenerativa/tendências
20.
BMC Cancer ; 21(1): 652, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34074257

RESUMO

BACKGROUND: Even though targeted therapies are available for cancers expressing oncogenic epidermal growth receptor (EGFR) and (or) human EGFR2 (HER2), acquired or intrinsic resistance often confounds therapy success. Common mechanisms of therapy resistance involve activating receptor point mutations and (or) upregulation of signaling downstream of EGFR/HER2 to Akt and (or) mitogen activated protein kinase (MAPK) pathways. However, additional pathways of resistance may exist thus, confounding successful therapy. METHODS: To determine novel mechanisms of EGFR/HER2 therapy resistance in breast cancer, gefitinib or lapatinib resistant variants were created from SKBR3 breast cancer cells. Syngenic therapy sensitive and resistant SKBR3 variants were characterized for mechanisms of resistance by mammosphere assays, viability assays, and western blotting for total and phospho proteins. RESULTS: Gefitinib and lapatinib treatments reduced mammosphere formation in the sensitive cells, but not in the therapy resistant variants, indicating enhanced mesenchymal and cancer stem cell-like characteristics in therapy resistant cells. The therapy resistant variants did not show significant changes in known therapy resistant pathways of AKT and MAPK activities downstream of EGFR/HER2. However, these cells exhibited elevated expression and activation of the small GTPase Rac, which is a pivotal intermediate of GFR signaling in EMT and metastasis. Therefore, the potential of the Rac inhibitors EHop-016 and MBQ-167 to overcome therapy resistance was tested, and found to inhibit viability and induce apoptosis of therapy resistant cells. CONCLUSIONS: Rac inhibition may represent a viable strategy for treatment of EGFR/HER2 targeted therapy resistant breast cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias da Mama/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Proteínas rac de Ligação ao GTP/antagonistas & inibidores , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Apoptose , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Carbazóis/farmacologia , Carbazóis/uso terapêutico , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Feminino , Mutação com Ganho de Função , Gefitinibe/farmacologia , Gefitinibe/uso terapêutico , Regulação Neoplásica da Expressão Gênica , Humanos , Lapatinib , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/genética , Mutação Puntual , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/farmacologia , Pirimidinas/uso terapêutico , Receptor ErbB-2/antagonistas & inibidores , Receptor ErbB-2/genética , Esferoides Celulares , Regulação para Cima
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