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1.
Exp Parasitol ; 259: 108715, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38336094

RESUMO

Hymenolepis diminuta a zoonotic tapeworm infection in human remains an important cestode model for anthelmintic study as it display common clinical symptoms like other adult human tapeworms during heavy infestation. The use of Lactobacillus as a probiotic is an alternative to drugs which have increased in research and usage considerably during the last decade. The present study aims to determine the anthelmintic efficacy of two probiotics, L. taiwanensis strain S29 and L. plantarum strain S27 against H. diminuta in infected rat. Four groups of animals, each with six numbers were randomly chosen as the negative control (Group I), positive control (infected) (Group II) and the infected treated with two probiotics Group III and Group IV respectively. Another four groups (Group V-VIII) were selected and further subdivided into four sub-groups to investigate the development of larvae to adult during probiotics treatment. Worm burden, egg per gram were determined after treatment with these two probiotics. Furthermore, hematological assays and levels of biochemical markers were estimated, tissue damage was assayed through histological study and intestinal mitochondria detection was done. Worm sustainability reduced about 70-90% and EPG count decreased by 81-94% in probiotics treated groups. A significant level of unsuccessful establishment of larvae was observed in the developmental phase. Improvement in hematological parameter along with some biochemical parameters in the host were significantly observed after treatment with probiotics. The architecture damaged caused in the intestine and mitochondria density due to parasite infection improved significantly as that of control after probiotics treatment.


Assuntos
Anti-Helmínticos , Infecções por Cestoides , Himenolepíase , Lactobacillus plantarum , Probióticos , Humanos , Ratos , Animais , Himenolepíase/tratamento farmacológico , Himenolepíase/parasitologia , Suíça , Lactobacillus , Anti-Helmínticos/uso terapêutico , Infecções por Cestoides/tratamento farmacológico , Infecções por Cestoides/prevenção & controle , Probióticos/uso terapêutico
2.
Parasitol Res ; 122(10): 2287-2299, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37507540

RESUMO

Tapeworm infections cause insidious and irreversible effects in the infected individuals and some of them have already shown resistance to available drugs. A search for alternative treatment is urgently required. Phenolic compounds are amongst the most researched natural substances for their medicinal use. The present study aims to determine anthelmintic efficacy of two polyphenols Gallic acid and Catechin against the zoonotic rat tapeworm Hymenolepis diminuta. Both compounds are potent anti-oxidants and play major roles in combating pathogens, while their anthelmintic property according to our knowledge is yet to be explored. The parasite model H. diminuta was procured from intestine of infected rats raised in our laboratory. Two sets of parasites were treated in vitro with 5, 10, 20 and 40 mg/ml concentrations of each Gallic Acid and Catechin separately, another set of parasites were treated with standard dose of Praziquantel in RPMI 1640, while still another set of worms were kept in RPMI 1640 at 37 ± 10C with 1% Dimethyl sulfoxide as control. Motility and structural alterations were the parameters assessed for anthelmintic efficacy of the compounds. After paralysis the worms were processed for morphological, histological, and ultrastructural study and observed under light and electron microscope. Dose-dependent efficacy was observed in both compounds. Shrinkage of suckers, deformed proglottids and architectural alteration of the tegument were observed throughout the body of treated parasites compared to control. Although in terms of time taken for paralysis and mortality Gallic acid was more effective than Catechin, the degree of morphological aberrations caused were almost similar, except histological alteration was more in Catechin treated worms than in Gallic acid. Nevertheless, both Gallic acid and Catechin are suggested to possess anthelmintic efficacy besides other health benefits but extended studies are required to compare their efficacy.


Assuntos
Anti-Helmínticos , Catequina , Himenolepíase , Hymenolepis diminuta , Hymenolepis , Parasitos , Ratos , Animais , Catequina/farmacologia , Catequina/uso terapêutico , Ácido Gálico/farmacologia , Anti-Helmínticos/farmacologia , Anti-Helmínticos/uso terapêutico , Himenolepíase/parasitologia
3.
Microorganisms ; 10(12)2022 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-36557581

RESUMO

Tapeworm infection continues to be an important cause of morbidity worldwide. Recent metagenomics studies have established a link between gut microbiota and parasite infection. The identification of gut probiotics is of foremost importance to explore its relationship and function with the parasite in the host. In this study, the gut content of hosts infected with tapeworm Hymenolepis diminuta and non-infected host gut were disected out to determine their Lactic acid bacterial (LAB) population in MRS agar and microbial community was analysed by metagenomics. The bacterial count was calculated on a bacterial counting chamber and their morphology was determined microscopically and biochemically. Further, to determine the safety profile antibiotic resistance test, antimicrobial, hemolytic activity, and adhesion capability were calculated. We found six dominant probiotic strains and a decrease in LAB load from 1.7-2.3 × 107 CFU/mL in the uninfected group to a range of 8.4 × 105 CFU/mL to 3.2 × 105 CFU/mL in the infected groups with respect to an increase in the parasite number from 10-18. In addition, we found a depletion in the probiotic relative abundance of Lactobacillus and an enrichment in potentially pathogenic Proteobacteria, Fusobacteria, and Streptococcus. Phylogenetic analysis of the six probiotics revealed a close similarity with different strains of L. brevis, L. johnsonii, L. taiwansis, L. reuteri, L. plantarum, and L. pentosus. Thus, this study suggests that the parasite inhibits probiotic colonization in the gut during its early establishment of infection inside the host.

4.
Cell Rep ; 40(12): 111358, 2022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-36130489

RESUMO

Many breast cancer (BC) patients suffer from complications of metastatic disease. To form metastases, cancer cells must become migratory and coordinate both invasive and proliferative programs at distant organs. Here, we identify srGAP1 as a regulator of a proliferative-to-invasive switch in BC cells. High-resolution light-sheet microscopy demonstrates that BC cells can form actin-rich protrusions during extravasation. srGAP1low cells display a motile and invasive phenotype that facilitates their extravasation from blood vessels, as shown in zebrafish and mouse models, while attenuating tumor growth. Interestingly, a population of srGAP1low cells remain as solitary disseminated tumor cells in the lungs of mice bearing BC tumors. Overall, srGAP1low cells have increased Smad2 activation and TGF-ß2 secretion, resulting in increased invasion and p27 levels to sustain quiescence. These findings identify srGAP1 as a mediator of a proliferative to invasive phenotypic switch in BC cells in vivo through a TGF-ß2-mediated signaling axis.


Assuntos
Actinas , Fator de Crescimento Transformador beta2 , Animais , Linhagem Celular Tumoral , Regulação para Baixo , Camundongos , Peixe-Zebra
5.
Nat Cancer ; 3(1): 90-107, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35121989

RESUMO

Cancer cells disseminate and seed in distant organs, where they can remain dormant for many years before forming clinically detectable metastases. Here we studied how disseminated tumor cells sense and remodel the extracellular matrix (ECM) to sustain dormancy. ECM proteomics revealed that dormant cancer cells assemble a type III collagen-enriched ECM niche. Tumor-derived type III collagen is required to sustain tumor dormancy, as its disruption restores tumor cell proliferation through DDR1-mediated STAT1 signaling. Second-harmonic generation two-photon microscopy further revealed that the dormancy-to-reactivation transition is accompanied by changes in type III collagen architecture and abundance. Analysis of clinical samples revealed that type III collagen levels were increased in tumors from patients with lymph node-negative head and neck squamous cell carcinoma compared to patients who were positive for lymph node colonization. Our data support the idea that the manipulation of these mechanisms could serve as a barrier to metastasis through disseminated tumor cell dormancy induction.


Assuntos
Colágeno Tipo III , Neoplasias de Cabeça e Pescoço , Proliferação de Células , Matriz Extracelular , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço
6.
Int Rev Cell Mol Biol ; 360: 65-98, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33962751

RESUMO

The actin cytoskeleton is a dynamic network that regulates cellular behavior from development to disease. By rearranging the actin cytoskeleton, cells are capable of migrating and invading during developmental processes; however, many of these cellular properties are hijacked by cancer cells to escape primary tumors and disseminate to distant organs in the body. In this review article, we highlight recent work describing how cancer cells regulate the actin cytoskeleton to achieve efficient invasion and metastatic colonization. We also review new imaging technologies that are capable of revealing the complex architecture and regulation of the actin cytoskeleton during motility and invasion of tumor cells.


Assuntos
Actinas/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Animais , Ciclo Celular , Movimento Celular , Transição Epitelial-Mesenquimal , Humanos , Metástase Neoplásica
7.
Scand J Immunol ; 93(4): e13001, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33247468

RESUMO

Lymphatic filariasis (LF) is the second leading cause of parasitic disabilities that affects millions of people in India and several other tropical countries. The complexity of this disease is endorsed by various immunopathological consequences such as lymphangitis, lymphadenitis and elephantiasis. The immune evasion strategies that a filarial parasite usually follows are chiefly initiated with the communication between the invaded parasites and parasite-derived molecules, with the Toll-like receptors (TLRs) present on the surface of the antigen-presenting cells (APCs). Classically, the filarial parasites interact with the DCs resulting in lowering of CD4+ T-cell responses. These CD4+ T-cell responses are the key players behind the immune-mediated pathologies associated with LF. In chronic stage, the canonical pro-inflammatory immune responses are shifted towards an anti-inflammatory subtype, which is favouring the parasite survivability within the host. The central theme of this review article is to present the overall immune response elicited when an APC, particularly a DC, encounters a filarial parasite.


Assuntos
Células Dendríticas/imunologia , Filariose Linfática/imunologia , Imunidade/imunologia , Parasitos/imunologia , Animais , Células Apresentadoras de Antígenos/imunologia , Antígenos de Helmintos/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/parasitologia , Células Dendríticas/parasitologia , Filariose Linfática/parasitologia , Humanos , Inflamação/imunologia , Inflamação/parasitologia , Receptores Toll-Like/imunologia
8.
Essays Biochem ; 63(5): 619-629, 2019 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-31654075

RESUMO

In this review, we present recent findings on the dynamic nature of the tumour microenvironment (TME) and how intravital microscopy studies have defined TME components in a spatiotemporal manner. Intravital microscopy has shed light into the nature of the TME, revealing structural details of both tumour cells and other TME co-habitants in vivo, how these cells communicate with each other, and how they are organized in three-dimensional space to orchestrate tumour growth, invasion, dissemination and metastasis. We will review different imaging tools, imaging reporters and fate-mapping strategies that have begun to uncover the complexity of the TME in vivo.


Assuntos
Neoplasias/patologia , Microambiente Tumoral , Animais , Matriz Extracelular/metabolismo , Humanos , Microscopia Intravital , Metástase Neoplásica/fisiopatologia , Transdução de Sinais/fisiologia , Microambiente Tumoral/fisiologia
9.
Cancer Discov ; 8(8): 1006-1025, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29903879

RESUMO

Advanced, metastatic melanomas frequently grow in subcutaneous tissues and portend a poor prognosis. Though subcutaneous tissues are largely composed of adipocytes, the mechanisms by which adipocytes influence melanoma are poorly understood. Using in vitro and in vivo models, we find that adipocytes increase proliferation and invasion of adjacent melanoma cells. Additionally, adipocytes directly transfer lipids to melanoma cells, which alters tumor cell metabolism. Adipocyte-derived lipids are transferred to melanoma cells through the FATP/SLC27A family of lipid transporters expressed on the tumor cell surface. Among the six FATP/SLC27A family members, melanomas significantly overexpress FATP1/SLC27A1. Melanocyte-specific FATP1 expression cooperates with BRAFV600E in transgenic zebrafish to accelerate melanoma development, an effect that is similarly seen in mouse xenograft studies. Pharmacologic blockade of FATPs with the small-molecule inhibitor Lipofermata abrogates lipid transport into melanoma cells and reduces melanoma growth and invasion. These data demonstrate that stromal adipocytes can drive melanoma progression through FATP lipid transporters and represent a new target aimed at interrupting adipocyte-melanoma cross-talk.Significance: We demonstrate that stromal adipocytes are donors of lipids that mediate melanoma progression. Adipocyte-derived lipids are taken up by FATP proteins that are aberrantly expressed in melanoma. Inhibition of FATPs decreases melanoma lipid uptake, invasion, and growth. We provide a mechanism for how stromal adipocytes drive tumor progression and demonstrate a novel microenvironmental therapeutic target. Cancer Discov; 8(8); 1006-25. ©2018 AACR.This article is highlighted in the In This Issue feature, p. 899.


Assuntos
Adipócitos/citologia , Proteínas de Transporte de Ácido Graxo/metabolismo , Ácidos Graxos/metabolismo , Melanoma/patologia , Proteínas Proto-Oncogênicas B-raf/genética , Células 3T3-L1 , Adipócitos/metabolismo , Animais , Animais Geneticamente Modificados , Transporte Biológico/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Técnicas de Cocultura , Progressão da Doença , Regulação Neoplásica da Expressão Gênica , Humanos , Melanoma/tratamento farmacológico , Melanoma/metabolismo , Camundongos , Mutação , Invasividade Neoplásica , Transplante de Neoplasias , Compostos de Espiro/administração & dosagem , Compostos de Espiro/farmacologia , Tiadiazóis/administração & dosagem , Tiadiazóis/farmacologia , Microambiente Tumoral , Regulação para Cima , Peixe-Zebra
10.
Dev Cell ; 45(5): 580-594.e7, 2018 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-29804876

RESUMO

Patterning of vertebrate melanophores is essential for mate selection and protection from UV-induced damage. Patterning can be influenced by circulating long-range factors, such as hormones, but it is unclear how their activity is controlled in recipient cells to prevent excesses in cell number and migration. The zebrafish wanderlust mutant harbors a mutation in the sheddase bace2 and exhibits hyperdendritic and hyperproliferative melanophores that localize to aberrant sites. We performed a chemical screen to identify suppressors of the wanderlust phenotype and found that inhibition of insulin/PI3Kγ/mTOR signaling rescues the defect. In normal physiology, Bace2 cleaves the insulin receptor, whereas its loss results in hyperactive insulin/PI3K/mTOR signaling. Insulin B, an isoform enriched in the head, drives the melanophore defect. These results suggest that insulin signaling is negatively regulated by melanophore-specific expression of a sheddase, highlighting how long-distance factors can be regulated in a cell-type-specific manner.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Padronização Corporal , Insulina/metabolismo , Melanóforos/fisiologia , Pigmentação , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/fisiologia , Secretases da Proteína Precursora do Amiloide/genética , Animais , Movimento Celular/fisiologia , Embrião não Mamífero/citologia , Embrião não Mamífero/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Insulina/genética , Melanóforos/citologia , Mutação , Fenótipo , Fosfatidilinositol 3-Quinases , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Peixe-Zebra/embriologia , Proteínas de Peixe-Zebra/genética
11.
J Vis Exp ; (124)2017 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-28605388

RESUMO

Cell adhesion, migration, and invasion are involved in many physiological and pathological processes. For example, during metastasis formation, tumor cells have to cross anatomical barriers to invade and migrate through the surrounding tissue in order to reach blood or lymphatic vessels. This requires the interaction between cells and the extracellular matrix (ECM). At the cellular level, many cells, including the majority of cancer cells, are able to form invadosomes, which are F-actin-based structures capable of degrading ECM. Invadosomes are protrusive actin structures that recruit and activate matrix metalloproteinases (MMPs). The molecular composition, density, organization, and stiffness of the ECM are crucial in regulating invadosome formation and activation. In vitro, a gelatin assay is the standard assay used to observe and quantify invadosome degradation activity. However, gelatin, which is denatured collagen I, is not a physiological matrix element. A novel assay using type I collagen fibrils was developed and used to demonstrate that this physiological matrix is a potent inducer of invadosomes. Invadosomes that form along the collagen fibrils are known as linear invadosomes due to their linear organization on the fibers. Moreover, molecular analysis of linear invadosomes showed that the discoidin domain receptor 1 (DDR1) is the receptor involved in their formation. These data clearly demonstrate the importance of using a physiologically relevant matrix in order to understand the complex interactions between cells and the ECM.


Assuntos
Podossomos/fisiologia , Actinas/metabolismo , Animais , Adesão Celular , Células Cultivadas , Colágeno Tipo I/metabolismo , Matriz Extracelular/metabolismo , Gelatina/metabolismo , Humanos
12.
Nature ; 546(7660): 676-680, 2017 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-28658220

RESUMO

Cutaneous melanoma is a type of cancer with an inherent potential for lymph node colonization, which is generally preceded by neolymphangiogenesis. However, sentinel lymph node removal does not necessarily extend the overall survival of patients with melanoma. Moreover, lymphatic vessels collapse and become dysfunctional as melanomas progress. Therefore, it is unclear whether (and how) lymphangiogenesis contributes to visceral metastasis. Soluble and vesicle-associated proteins secreted by tumours and/or their stroma have been proposed to condition pre-metastatic sites in patients with melanoma. Still, the identities and prognostic value of lymphangiogenic mediators remain unclear. Moreover, our understanding of lymphangiogenesis (in melanomas and other tumour types) is limited by the paucity of mouse models for live imaging of distal pre-metastatic niches. Injectable lymphatic tracers have been developed, but their limited diffusion precludes whole-body imaging at visceral sites. Vascular endothelial growth factor receptor 3 (VEGFR3) is an attractive 'lymphoreporter' because its expression is strongly downregulated in normal adult lymphatic endothelial cells, but is activated in pathological situations such as inflammation and cancer. Here, we exploit this inducibility of VEGFR3 to engineer mouse melanoma models for whole-body imaging of metastasis generated by human cells, clinical biopsies or endogenously deregulated oncogenic pathways. This strategy revealed early induction of distal pre-metastatic niches uncoupled from lymphangiogenesis at primary lesions. Analyses of the melanoma secretome and validation in clinical specimens showed that the heparin-binding factor midkine is a systemic inducer of neo-lymphangiogenesis that defines patient prognosis. This role of midkine was linked to a paracrine activation of the mTOR pathway in lymphatic endothelial cells. These data support the use of VEGFR3 reporter mice as a 'MetAlert' discovery platform for drivers and inhibitors of metastasis.


Assuntos
Citocinas/metabolismo , Vasos Linfáticos/metabolismo , Metástase Neoplásica/diagnóstico por imagem , Metástase Neoplásica/patologia , Imagem Corporal Total/métodos , Animais , Modelos Animais de Doenças , Progressão da Doença , Células Endoteliais/metabolismo , Feminino , Genes Reporter , Humanos , Linfangiogênese , Vasos Linfáticos/patologia , Masculino , Melanoma/diagnóstico por imagem , Melanoma/metabolismo , Melanoma/patologia , Camundongos , Midkina , Comunicação Parácrina , Prognóstico , Recidiva , Reprodutibilidade dos Testes , Serina-Treonina Quinases TOR/metabolismo , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/análise , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Sci Rep ; 6: 35298, 2016 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-27748415

RESUMO

During tumor progression, alternative splicing gives rise to different Mena protein isoforms. We analyzed how Mena11a, an isoform enriched in epithelia and epithelial-like cells, affects Mena-dependent regulation of actin dynamics and cell behavior. While other Mena isoforms promote actin polymerization and drive membrane protrusion, we find that Mena11a decreases actin polymerization and growth factor-stimulated membrane protrusion at lamellipodia. Ectopic Mena11a expression slows mesenchymal-like cell motility, while isoform-specific depletion of endogenous Mena11a in epithelial-like tumor cells perturbs cell:cell junctions and increases membrane protrusion and overall cell motility. Mena11a can dampen membrane protrusion and reduce actin polymerization in the absence of other Mena isoforms, indicating that it is not simply an inactive Mena isoform. We identify a phosphorylation site within 11a that is required for some Mena11a-specific functions. RNA-seq data analysis from patient cohorts demonstrates that the difference between mRNAs encoding constitutive Mena sequences and those containing the 11a exon correlates with metastasis in colorectal cancer, suggesting that 11a exon exclusion contributes to invasive phenotypes and leads to poor clinical outcomes.


Assuntos
Citoesqueleto de Actina , Neoplasias Colorretais/metabolismo , Regulação Neoplásica da Expressão Gênica , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Processamento Alternativo , Animais , Biomarcadores/metabolismo , Adesão Celular , Comunicação Celular , Membrana Celular/metabolismo , Movimento Celular , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Receptores ErbB/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Células HEK293 , Humanos , Pulmão/embriologia , Pulmão/metabolismo , Células MCF-7 , Camundongos , Fenótipo , Fosforilação , Pseudópodes/patologia , Alvéolos Pulmonares/metabolismo , Pele/embriologia , Pele/metabolismo , Resultado do Tratamento , Regulação para Cima , Cicatrização
14.
PLoS One ; 8(9): e74950, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24066160

RESUMO

It has been demonstrated for some cancers that the frequency of somatic oncogenic mutations may vary in ancestral populations. To determine whether key driver alterations might occur at different frequencies in colorectal cancer, we applied a high-throughput genotyping platform (OncoMap) to query 385 mutations across 33 known cancer genes in colorectal cancer DNA from 83 Asian, 149 Black and 195 White patients. We found that Asian patients had fewer canonical oncogenic mutations in the genes tested (60% vs Black 79% (P = 0.011) and White 77% (P = 0.015)), and that BRAF mutations occurred at a higher frequency in White patients (17% vs Asian 4% (P = 0.004) and Black 7% (P = 0.014)). These results suggest that the use of genomic approaches to elucidate the different ancestral determinants harbored by patient populations may help to more precisely and effectively treat colorectal cancer.


Assuntos
Neoplasias Colorretais/genética , Taxa de Mutação , Proteínas Proto-Oncogênicas B-raf/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Povo Asiático , População Negra , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , População Branca , Adulto Jovem
15.
Blood ; 117(8): 2433-40, 2011 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-21209378

RESUMO

Cutaneous T-cell lymphomas (CTCLs) are malignancies of skin-homing lymphoid cells, which have so far not been investigated thoroughly for common oncogenic mutations. We screened 90 biopsy specimens from CTCL patients (41 mycosis fungoides, 36 Sézary syndrome, and 13 non-mycosis fungoides/Sézary syndrome CTCL) for somatic mutations using OncoMap technology. We detected oncogenic mutations for the RAS pathway in 4 of 90 samples. One mycosis fungoides and one pleomorphic CTCL harbored a KRAS(G13D) mutation; one Sézary syndrome and one CD30(+) CTCL harbored a NRAS(Q61K) amino acid change. All mutations were found in stage IV patients (4 of 42) who showed significantly decreased overall survival compared with stage IV patients without mutations (P = .04). In addition, we detected a NRAS(Q61K) mutation in the CTCL cell line Hut78. Knockdown of NRAS by siRNA induced apoptosis in mutant Hut78 cells but not in CTCL cell lines lacking RAS mutations. The NRAS(Q61K) mutation sensitized Hut78 cells toward growth inhibition by the MEK inhibitors U0126, AZD6244, and PD0325901. Furthermore, we found that MEK inhibitors exclusively induce apoptosis in Hut78 cells. Taken together, we conclude that RAS mutations are rare events at a late stage of CTCL, and our preclinical results suggest that such late-stage patients profit from MEK inhibitors.


Assuntos
Ensaios de Triagem em Larga Escala/métodos , Linfoma Cutâneo de Células T/genética , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Mutação , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas/genética , Transdução de Sinais/genética , Quinases raf/metabolismo , Proteínas ras/metabolismo , Biópsia , Humanos , Linfoma Cutâneo de Células T/patologia , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Micose Fungoide , Estadiamento de Neoplasias , Inibidores de Proteínas Quinases/farmacologia , Síndrome de Sézary , Transdução de Sinais/efeitos dos fármacos , Proteínas ras/genética
16.
PLoS One ; 4(11): e7887, 2009 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-19924296

RESUMO

BACKGROUND: Detection of critical cancer gene mutations in clinical tumor specimens may predict patient outcomes and inform treatment options; however, high-throughput mutation profiling remains underdeveloped as a diagnostic approach. We report the implementation of a genotyping and validation algorithm that enables robust tumor mutation profiling in the clinical setting. METHODOLOGY: We developed and implemented an optimized mutation profiling platform ("OncoMap") to interrogate approximately 400 mutations in 33 known oncogenes and tumor suppressors, many of which are known to predict response or resistance to targeted therapies. The performance of OncoMap was analyzed using DNA derived from both frozen and FFPE clinical material in a diverse set of cancer types. A subsequent in-depth analysis was conducted on histologically and clinically annotated pediatric gliomas. The sensitivity and specificity of OncoMap were 93.8% and 100% in fresh frozen tissue; and 89.3% and 99.4% in FFPE-derived DNA. We detected known mutations at the expected frequencies in common cancers, as well as novel mutations in adult and pediatric cancers that are likely to predict heightened response or resistance to existing or developmental cancer therapies. OncoMap profiles also support a new molecular stratification of pediatric low-grade gliomas based on BRAF mutations that may have immediate clinical impact. CONCLUSIONS: Our results demonstrate the clinical feasibility of high-throughput mutation profiling to query a large panel of "actionable" cancer gene mutations. In the future, this type of approach may be incorporated into both cancer epidemiologic studies and clinical decision making to specify the use of many targeted anticancer agents.


Assuntos
Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Mutação , Neoplasias/metabolismo , Algoritmos , Códon , Análise Mutacional de DNA , Primers do DNA/genética , Genótipo , Glioma/genética , Humanos , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas B-raf/genética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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