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1.
J Exp Clin Cancer Res ; 40(1): 364, 2021 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-34784956

RESUMO

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common and lethal malignant tumours worldwide. Sorafenib (SOR) is one of the most effective single-drug systemic therapy against advanced HCC, but the identification of novel combination regimens for a continued improvement in overall survival is a big challenge. Recent studies highlighted the crucial role of focal adhesion kinase (FAK) in HCC growth. The aim of this study was to investigate the antitumor effects of three different FAK inhibitors (FAKi), alone or in combination with SOR, using in vitro and in vivo models of HCC. METHODS: The effect of PND1186, PF431396, TAE226 on cell viability was compared to SOR. Among them TAE226, emerging as the most effective FAKi, was tested alone or in combination with SOR using 2D/3D human HCC cell line cultures and HCC xenograft murine models. The mechanisms of action were assessed by gene/protein expression and imaging approaches, combined with high-throughput methods. RESULTS: TAE226 was the more effective FAKi to be combined with SOR against HCC. Combined TAE226 and SOR treatment reduced HCC growth both in vitro and in vivo by affecting tumour-promoting gene expression and inducing epigenetic changes via dysregulation of FAK nuclear interactome. We characterized a novel nuclear functional interaction between FAK and the NuRD complex. TAE226-mediated FAK depletion and SOR-promoted MAPK down-modulation caused a decrease in the nuclear amount of HDAC1/2 and a consequent increase of the histone H3 lysine 27 acetylation, thus counteracting histone H3 lysine 27 trimethylation. CONCLUSIONS: Altogether, our findings provide the first evidence that TAE226 combined with SOR efficiently reduces HCC growth in vitro and in vivo. Also, our data highlight that deep analysis of FAK nuclear interactome may lead to the identification of new promising targets for HCC therapy.

2.
Int J Mol Sci ; 22(19)2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34639012

RESUMO

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood. About 25% of RMS expresses fusion oncoproteins such as PAX3/PAX7-FOXO1 (fusion-positive, FP) while fusion-negative (FN)-RMS harbors RAS mutations. Radiotherapy (RT) plays a crucial role in local control but metastatic RMS is often radio-resistant. HDAC inhibitors (HDACi) radio-sensitize different cancer cells types. Thus, we evaluated MS-275 (Entinostat), a Class I and IV HDACi, in combination with RT on RMS cells in vitro and in vivo. MS-275 reversibly hampered cell survival in vitro in FN-RMS RD (RASmut) and irreversibly in FP-RMS RH30 cell lines down-regulating cyclin A, B, and D1, up-regulating p21 and p27 and reducing ERKs activity, and c-Myc expression in RD and PI3K/Akt/mTOR activity and N-Myc expression in RH30 cells. Further, MS-275 and RT combination reduced colony formation ability of RH30 cells. In both cell lines, co-treatment increased DNA damage repair inhibition and reactive oxygen species formation, down-regulated NRF2, SOD, CAT and GPx4 anti-oxidant genes and improved RT ability to induce G2 growth arrest. MS-275 inhibited in vivo growth of RH30 cells and completely prevented the growth of RT-unresponsive RH30 xenografts when combined with radiation. Thus, MS-275 could be considered as a radio-sensitizing agent for the treatment of intrinsically radio-resistant PAX3-FOXO1 RMS.


Assuntos
Benzamidas/farmacologia , Proteínas de Fusão Oncogênica/genética , Fatores de Transcrição Box Pareados/genética , Piridinas/farmacologia , Tolerância a Radiação/efeitos dos fármacos , Tolerância a Radiação/genética , Radiossensibilizantes/farmacologia , Rabdomiossarcoma/genética , Animais , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos da radiação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Rabdomiossarcoma/metabolismo , Rabdomiossarcoma/radioterapia
3.
Cancer Res ; 81(21): 5451-5463, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34462275

RESUMO

Ionizing radiation (IR) and chemotherapy are mainstays of treatment for patients with rhabdomyosarcoma, yet the molecular mechanisms that underlie the success or failure of radiotherapy remain unclear. The transcriptional repressor SNAI2 was previously identified as a key regulator of IR sensitivity in normal and malignant stem cells through its repression of the proapoptotic BH3-only gene PUMA/BBC3. Here, we demonstrate a clear correlation between SNAI2 expression levels and radiosensitivity across multiple rhabdomyosarcoma cell lines. Modulating SNAI2 levels in rhabdomyosarcoma cells through its overexpression or knockdown altered radiosensitivity in vitro and in vivo. SNAI2 expression reliably promoted overall cell growth and inhibited mitochondrial apoptosis following exposure to IR, with either variable or minimal effects on differentiation and senescence, respectively. Importantly, SNAI2 knockdown increased expression of the proapoptotic BH3-only gene BIM, and chromatin immunoprecipitation sequencing experiments established that SNAI2 is a direct repressor of BIM/BCL2L11. Because the p53 pathway is nonfunctional in the rhabdomyosarcoma cells used in this study, we have identified a new, p53-independent SNAI2/BIM signaling axis that could potentially predict clinical responses to IR treatment and be exploited to improve rhabdomyosarcoma therapy. SIGNIFICANCE: SNAI2 is identified as a major regulator of radiation-induced apoptosis in rhabdomyosarcoma through previously unknown mechanisms independent of p53.

4.
Int J Radiat Biol ; 97(7): 943-957, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33979259

RESUMO

PURPOSE: Herein we describe the in vitro and in vivo activity of FK228 (Romidepsin), an inhibitor of class I HDACs, in counteracting and radiosensitizing embryonal (ERMS, fusion-negative) and alveolar (ARMS, fusion-positive) rhabdomyosarcoma (RMS). METHODS: RH30 (ARMS, fusion-positive) and RD (ERMS, fusion-negative) cell lines and human multipotent mesenchymal stromal cells (HMSC) were used. Flow cytometry analysis, RT-qPCR, western blotting and enzymatic assays were performed. Irradiation was delivered by using an x-6 MV photon linear accelerator. FK228 (1.2 mg/kg) in vivo activity, combined or not with radiation therapy (2 Gy), was assessed in murine xenografts. RESULTS: Compared to HMSC, RMS expressed low levels of class I HDACs. In vitro, FK228, as single agents, reversibly downregulated class I HDACs expression and activity and induced oxidative stress, DNA damage and a concomitant growth arrest associated with PARP-1-mediated transient non-apoptotic cell death. Surviving cells upregulated the expression of cyclin A, B, D1, p27, Myc and activated PI3K/Akt/mTOR and MAPK signaling, known to be differently involved in cancer chemoresistance. Interestingly, while no radiosensitizing effects were detected, in vitro or in vivo, on RD cells, FK228 markedly radiosensitized RH30 cells by impairing antioxidant and DSBs repair pathways in vitro. Further, FK228 when combined with RT in vivo significantly reduced tumor mass in mouse RH30 xenografts. CONCLUSION: FK228 did not show antitumor activity as a single agent whilst its combination with RT resulted in radiosensitization of fusion-positive RMS cells, thus representing a possible strategy for the treatment of the most aggressive RMS subtype.


Assuntos
Transformação Celular Neoplásica , Depsipeptídeos/farmacologia , Fenótipo , Radiossensibilizantes/farmacologia , Rabdomiossarcoma/patologia , Animais , Apoptose/efeitos da radiação , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/efeitos da radiação , Linhagem Celular Tumoral , Humanos , Camundongos
5.
Cell Death Dis ; 12(5): 452, 2021 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-33958580

RESUMO

One of the critical events that regulates muscle cell differentiation is the replacement of the lamin B receptor (LBR)-tether with the lamin A/C (LMNA)-tether to remodel transcription and induce differentiation-specific genes. Here, we report that localization and activity of the LBR-tether are crucially dependent on the muscle-specific chaperone HSPB3 and that depletion of HSPB3 prevents muscle cell differentiation. We further show that HSPB3 binds to LBR in the nucleoplasm and maintains it in a dynamic state, thus promoting the transcription of myogenic genes, including the genes to remodel the extracellular matrix. Remarkably, HSPB3 overexpression alone is sufficient to induce the differentiation of two human muscle cell lines, LHCNM2 cells, and rhabdomyosarcoma cells. We also show that mutant R116P-HSPB3 from a myopathy patient with chromatin alterations and muscle fiber disorganization, forms nuclear aggregates that immobilize LBR. We find that R116P-HSPB3 is unable to induce myoblast differentiation and instead activates the unfolded protein response. We propose that HSPB3 is a specialized chaperone engaged in muscle cell differentiation and that dysfunctional HSPB3 causes neuromuscular disease by deregulating LBR.


Assuntos
Proteínas de Choque Térmico Pequenas/genética , Proteínas de Choque Térmico/metabolismo , Desenvolvimento Muscular/imunologia , Músculo Esquelético/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Linhagem Celular , Células HeLa , Humanos , Músculo Esquelético/citologia , Transfecção
6.
Nat Commun ; 12(1): 192, 2021 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-33420019

RESUMO

Rhabdomyosarcoma (RMS) is an aggressive pediatric malignancy of the muscle, that includes Fusion Positive (FP)-RMS harboring PAX3/7-FOXO1 and Fusion Negative (FN)-RMS commonly with RAS pathway mutations. RMS express myogenic master transcription factors MYOD and MYOG yet are unable to terminally differentiate. Here, we report that SNAI2 is highly expressed in FN-RMS, is oncogenic, blocks myogenic differentiation, and promotes growth. MYOD activates SNAI2 transcription via super enhancers with striped 3D contact architecture. Genome wide chromatin binding analysis demonstrates that SNAI2 preferentially binds enhancer elements and competes with MYOD at a subset of myogenic enhancers required for terminal differentiation. SNAI2 also suppresses expression of a muscle differentiation program modulated by MYOG, MEF2, and CDKN1A. Further, RAS/MEK-signaling modulates SNAI2 levels and binding to chromatin, suggesting that the differentiation blockade by oncogenic RAS is mediated in part by SNAI2. Thus, an interplay between SNAI2, MYOD, and RAS prevents myogenic differentiation and promotes tumorigenesis.


Assuntos
Carcinogênese/metabolismo , Diferenciação Celular , Proteína MyoD/metabolismo , Proteínas de Fusão Oncogênica/metabolismo , Rabdomiossarcoma/genética , Rabdomiossarcoma/metabolismo , Fatores de Transcrição da Família Snail/metabolismo , Animais , Carcinogênese/genética , Diferenciação Celular/genética , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Xenoenxertos , Humanos , Fatores de Transcrição MEF2/metabolismo , Masculino , Camundongos , Camundongos SCID , Desenvolvimento Muscular/genética , Proteína MyoD/genética , Miogenina/metabolismo , Proteínas de Fusão Oncogênica/genética , Oncogenes , Rabdomiossarcoma/patologia , Rabdomiossarcoma Alveolar/genética , Rabdomiossarcoma Embrionário/genética , Fatores de Transcrição da Família Snail/genética , Transcriptoma
7.
Int J Mol Sci ; 21(22)2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33182556

RESUMO

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of children and adolescents. The fusion-positive (FP)-RMS variant expressing chimeric oncoproteins such as PAX3-FOXO1 and PAX7-FOXO1 is at high risk. The fusion negative subgroup, FN-RMS, has a good prognosis when non-metastatic. Despite a multimodal therapeutic approach, FP-RMS and metastatic FN-RMS often show a dismal prognosis with 5-year survival of less than 30%. Therefore, novel targets need to be discovered to develop therapies that halt tumor progression, reducing long-term side effects in young patients. Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that regulates focal contacts at the cellular edges. It plays a role in cell motility, survival, and proliferation in response to integrin and growth factor receptors' activation. FAK is often dysregulated in cancer, being upregulated and/or overactivated in several adult and pediatric tumor types. In RMS, both in vitro and preclinical studies point to a role of FAK in tumor cell motility/invasion and proliferation, which is inhibited by FAK inhibitors. In this review, we summarize the data on FAK expression and modulation in RMS. Moreover, we give an overview of the approaches to inhibit FAK in both preclinical and clinical cancer settings.


Assuntos
Quinase 1 de Adesão Focal/fisiologia , Rabdomiossarcoma/fisiopatologia , Neoplasias de Tecidos Moles/fisiopatologia , Animais , Carcinogênese , Criança , Ensaios Clínicos como Assunto , Quinase 1 de Adesão Focal/antagonistas & inibidores , Quinase 1 de Adesão Focal/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Modelos Biológicos , Terapia de Alvo Molecular , Desenvolvimento Muscular , Invasividade Neoplásica , Metástase Neoplásica , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/fisiologia , Inibidores de Proteínas Quinases/farmacologia , Rabdomiossarcoma/genética , Rabdomiossarcoma/terapia , Transdução de Sinais , Neoplasias de Tecidos Moles/genética , Neoplasias de Tecidos Moles/terapia
8.
Front Pharmacol ; 11: 1230, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32903585

RESUMO

Cyclin-Dependent Kinases (CDKs) are well-known reliable targets for cancer treatment being often deregulated. Among them, since the transcription-associated CDK9 represents the sentry of cell transcriptional homeostasis, it can be a valuable target for managing cancers in which the transcriptional machinery is dysregulated by tumor-driver oncogenes. Here we give an overview of some natural compounds identified as CDK inhibitors with reported activity also against CDK9, that were taken as a model for the development of highly active synthetic anti-CDK9 agents. After, we summarize the data on CDK9 inhibition in a group of rare pediatric solid tumors such as rhabdomyosarcoma, Ewing's sarcoma, synovial sarcoma and malignant rhabdoid tumors (soft tissue sarcomas), highlighting the more recent results in this field. Finally, we discuss the perspective and challenge of CDK9 modulation in cancer.

9.
iScience ; 23(5): 101103, 2020 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-32416589

RESUMO

Core regulatory transcription factors (CR TFs) establish enhancers with logical ordering during embryogenesis and development. Here we report that in fusion-positive rhabdomyosarcoma, a cancer of the muscle lineage, the chief oncogene PAX3-FOXO1 is driven by a translocated FOXO1 super enhancer (SE) restricted to a late stage of myogenesis. Using chromatin conformation capture techniques, we demonstrate that the extensive FOXO1 cis-regulatory domain interacts with PAX3. Furthermore, RNA sequencing and chromatin immunoprecipitation sequencing data in tumors bearing rare PAX translocations implicate enhancer miswiring across all fusion-positive tumors. HiChIP of H3K27ac showed connectivity between the FOXO1 SE, additional intra-domain enhancers, and the PAX3 promoter. We show that PAX3-FOXO1 transcription is diminished when this network of enhancers is ablated by CRISPR. Our data reveal a hijacked enhancer network that disrupts the stepwise CR TF logic of normal skeletal muscle development (PAX3 to MYOD to MYOG), replacing it with an "infinite loop" enhancer logic that locks rhabdomyosarcoma in an undifferentiated stage.

10.
ACS Med Chem Lett ; 11(5): 977-983, 2020 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-32435414

RESUMO

Since the histone modifying enzymes EZH2 and HDACs control a number of epigenetic-dependent carcinogenic pathways, we designed the first-in-class dual EZH2/HDAC inhibitor 5 displaying (sub)micromolar inhibition against both targets. When tested in several cancer cell lines, the hybrid 5 impaired cell viability at low micromolar level and in leukemia U937 and rhabdomyosarcoma RH4 cells provided G1 arrest, apoptotic induction, and increased differentiation, associated with an increase of acetyl-H3 and acetyl-α-tubulin and a decrease of H3K27me3 levels. In glioblastoma U87 cells, 5 hampered epithelial to mesenchymal transition by increasing the E-cadherin expression, thus proposing itself as a useful candidate for anticancer therapy.

11.
Front Chem ; 8: 178, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32232030

RESUMO

The RNA-guided clustered regularly interspaced palindromic repeats (CRISPR)/associated nuclease 9 (Cas9)-based genome editing technology has increasingly become a recognized method for translational research. In oncology, the ease and versatility of CRISPR/Cas9 has made it possible to obtain many results in the identification of new target genes and in unravel mechanisms of resistance to therapy. The majority of the studies have been made on adult tumors so far. In this mini review we present an overview on the major aspects of CRISPR/Cas9 technology with a focus on a group of rare pediatric malignancies, soft tissue sarcomas, on which this approach is having promising results.

12.
Nat Genet ; 51(12): 1714-1722, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31784732

RESUMO

Core regulatory transcription factors (CR TFs) orchestrate the placement of super-enhancers (SEs) to activate transcription of cell-identity specifying gene networks, and are critical in promoting cancer. Here, we define the core regulatory circuitry of rhabdomyosarcoma and identify critical CR TF dependencies. These CR TFs build SEs that have the highest levels of histone acetylation, yet paradoxically the same SEs also harbor the greatest amounts of histone deacetylases. We find that hyperacetylation selectively halts CR TF transcription. To investigate the architectural determinants of this phenotype, we used absolute quantification of architecture (AQuA) HiChIP, which revealed erosion of native SE contacts, and aberrant spreading of contacts that involved histone acetylation. Hyperacetylation removes RNA polymerase II (RNA Pol II) from core regulatory genetic elements, and eliminates RNA Pol II but not BRD4 phase condensates. This study identifies an SE-specific requirement for balancing histone modification states to maintain SE architecture and CR TF transcription.


Assuntos
Histonas/metabolismo , Rabdomiossarcoma/genética , Fatores de Transcrição/genética , Acetilação , Benzamidas/farmacologia , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Elementos Facilitadores Genéticos , Proteína Forkhead Box O1/genética , Proteína Forkhead Box O1/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Redes Reguladoras de Genes , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Histonas/genética , Humanos , Piridinas/farmacologia , RNA Polimerase II/genética , RNA Polimerase II/metabolismo , Estabilidade de RNA , Fatores de Transcrição SOXE/genética , Análise de Célula Única
13.
Nat Commun ; 10(1): 3004, 2019 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-31285436

RESUMO

Identity determining transcription factors (TFs), or core regulatory (CR) TFs, are governed by cell-type specific super enhancers (SEs). Drugs to selectively inhibit CR circuitry are of high interest for cancer treatment. In alveolar rhabdomyosarcoma, PAX3-FOXO1 activates SEs to induce the expression of other CR TFs, providing a model system for studying cancer cell addiction to CR transcription. Using chemical genetics, the systematic screening of chemical matter for a biological outcome, here we report on a screen for epigenetic chemical probes able to distinguish between SE-driven transcription and constitutive transcription. We find that chemical probes along the acetylation-axis, and not the methylation-axis, selectively disrupt CR transcription. Additionally, we find that histone deacetylases (HDACs) are essential for CR TF transcription. We further dissect the contribution of HDAC isoforms using selective inhibitors, including the newly developed selective HDAC3 inhibitor LW3. We show HDAC1/2/3 are the co-essential isoforms that when co-inhibited halt CR transcription, making CR TF sites hyper-accessible and disrupting chromatin looping.


Assuntos
Elementos Facilitadores Genéticos/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/metabolismo , Rabdomiossarcoma/genética , Acetilação/efeitos dos fármacos , Linhagem Celular Tumoral , Cromatina/efeitos dos fármacos , Cromatina/metabolismo , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Ensaios de Triagem em Larga Escala , Inibidores de Histona Desacetilases/química , Histona Desacetilases/química , Humanos , Simulação de Dinâmica Molecular , Sondas Moleculares/química , Sondas Moleculares/farmacologia , Proteínas de Fusão Oncogênica/genética , Fatores de Transcrição Box Pareados/genética , Cultura Primária de Células , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismo , Rabdomiossarcoma/patologia , Análise de Sequência de RNA , Transcrição Genética/efeitos dos fármacos
14.
Pediatr Blood Cancer ; 66(10): e27869, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31222885

RESUMO

Overall survival rates for pediatric patients with high-risk or relapsed rhabdomyosarcoma (RMS) have not improved significantly since the 1980s. Recent studies have identified a number of targetable vulnerabilities in RMS, but these discoveries have infrequently translated into clinical trials. We propose streamlining the process by which agents are selected for clinical evaluation in RMS. We believe that strong consideration should be given to the development of combination therapies that add biologically targeted agents to conventional cytotoxic drugs. One example of this type of combination is the addition of the WEE1 inhibitor AZD1775 to the conventional cytotoxic chemotherapeutics, vincristine and irinotecan.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Desenvolvimento de Medicamentos/métodos , Descoberta de Drogas/métodos , Rabdomiossarcoma , Criança , Humanos , Projetos de Pesquisa
15.
Front Oncol ; 8: 475, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30416982

RESUMO

Soft tissue sarcomas (STSs) are an uncommon group of solid tumors that can arise throughout the human lifespan. Despite their commonality as non-bony cancers that develop from mesenchymal cell precursors, they are heterogeneous in their genetic profiles, histology, and clinical features. This has made it difficult to identify a single target or therapy specific to STSs. And while there is no one cell of origin ascribed to all STSs, the cancer stem cell (CSC) principle-that a subpopulation of tumor cells possesses stem cell-like properties underlying tumor initiation, therapeutic resistance, disease recurrence, and metastasis-predicts that ultimately it should be possible to identify a feature common to all STSs that could function as a therapeutic Achilles' heel. Here we review the published evidence for CSCs in each of the most common STSs, then focus on the methods used to study CSCs, the developmental signaling pathways usurped by CSCs, and the epigenetic alterations critical for CSC identity that may be useful for further study of STS biology. We conclude with discussion of some challenges to the field and future directions.

16.
ACS Chem Neurosci ; 9(12): 3166-3174, 2018 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-30015470

RESUMO

Temozolomide (TMZ) is the current first-line chemotherapy for treatment of glioblastoma multiforme (GBM). However, similar to other brain therapeutic compounds, access of TMZ to brain tumors is impaired by the blood-brain barrier (BBB) leading to poor response for GBM patients. To overcome this major hurdle, we have synthesized a set of TMZ-encapsulating nanomedicines made of four cationic liposome (CL) formulations with systematic changes in lipid composition and physical-chemical properties. The targeting nature of this nanomedicine is provided by the recruitment of proteins, with natural targeting capacity, in the biomolecular corona (BC) layer that forms around CLs after exposure to human plasma (HP). TMZ-loaded CL-BC complexes were thoroughly characterized by dynamic light scattering (DLS), electrophoretic light scattering (ELS), and nanoliquid chromatography tandem mass spectrometry (nano-LC MS/MS). BCs were found to be enriched of typical BC fingerprints (BCFs) (e.g., Apolipoproteins, Vitronectin, and vitamin K-dependent protein), which have a substantial capacity in binding to receptors that are overexpressed at the BBB (e.g., scavenger receptor class B, type I and low-density lipoprotein receptor). We found that the CL formulation exhibiting the highest levels of targeting BCFs had larger uptake in human umbilical vein endothelial cells (HUVECs) that are commonly used as an in vitro model of the BBB. This formulation could also deliver TMZ to the human glioblastoma U-87 MG cell line and thus substantially enhance their antitumor efficacy compared to corona free CLs. Thus, we propose that the BC-based nanomedicines may pave a more effective way for efficient treatment of GBM.


Assuntos
Antineoplásicos Alquilantes/administração & dosagem , Barreira Hematoencefálica/metabolismo , Neoplasias Encefálicas/tratamento farmacológico , Encéfalo/metabolismo , Glioblastoma/tratamento farmacológico , Lipossomos/farmacocinética , Temozolomida/administração & dosagem , Apolipoproteínas/metabolismo , Linhagem Celular Tumoral , Cromatografia Líquida , Sistemas de Liberação de Medicamentos , Difusão Dinâmica da Luz , Células Endoteliais da Veia Umbilical Humana , Humanos , Técnicas In Vitro , Nanopartículas , Receptores de LDL/metabolismo , Receptores Depuradores Classe C/metabolismo , Espectrometria de Massas em Tandem , Vitronectina/metabolismo
18.
BMC Cancer ; 18(1): 31, 2018 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-29304781

RESUMO

BACKGROUND: The Intratumoral Microvessel Density (IMVD) is commonly used to quantify tumoral vascularization and is usually assessed by pan-endothelial markers, such as CD31. Endoglin (CD105) is a protein predominantly expressed in proliferating endothelium and the IMVD determined by this marker measures specifically the neovascularization. In this study, we investigated the CD105 expression in pediatric rhabdomyosarcoma and assessed the neovascularization by using the angiogenic ratio IMVD-CD105 to IMVD-CD31. METHODS: Paraffin-embedded archival tumor specimens were selected from 65 pediatric patients affected by rhabdomyosarcoma. The expression levels of CD105, CD31 and Vascular Endothelial Growth Factor (VEGF) were investigated in 30 cases (18 embryonal and 12 alveolar) available for this study. The IMVD-CD105 to IMVD-CD31 expression ratio was correlated with clinical and pathologic features of these patients. RESULTS: We found a specific expression of endoglin (CD105) in endothelial cells of all the rhabdomyosarcoma specimens analyzed. We observed a significant positive correlation between the IMVD individually measured by CD105 and CD31. The CD105/CD31 expression ratio was significantly higher in patients with lower survival and embryonal histology. Indeed, patients with a CD105/CD31 expression ratio < 1.3 had a significantly increased OS (88%, 95%CI, 60%-97%) compared to patients with higher values (40%, 95%CI, 12%-67%). We did not find any statistical correlation among VEGF and EFS, OS and CD105/CD31 expression ratio. CONCLUSION: CD105 is expressed on endothelial cells of rhabdomyosarcoma and represent a useful tool to quantify neovascularization in this tumor. If confirmed by further studies, these results will indicate that CD105 is a potential target for combined therapies in rhabdomyosarcoma.


Assuntos
Endoglina/genética , Neovascularização Patológica/genética , Rabdomiossarcoma/genética , Adolescente , Biomarcadores Tumorais/genética , Criança , Pré-Escolar , Intervalo Livre de Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Lactente , Recém-Nascido , Masculino , Neovascularização Patológica/patologia , Molécula-1 de Adesão Celular Endotelial a Plaquetas/genética , Rabdomiossarcoma/patologia , Fator A de Crescimento do Endotélio Vascular/genética
19.
Front Microbiol ; 8: 689, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28484438

RESUMO

Viruses infect host cells releasing their genome (DNA or RNA) containing all information needed to replicate themselves. The viral genome takes control of the cells and helps the virus to evade the host immune system. Some viruses alter the functions of infected cells without killing them. In some cases infected cells lose control over normal cell proliferation and becomes cancerous. Viruses, such as HCMV and HIV-1, may leave their viral genome in the host cells for a certain period (latency) and begin to replicate when the cells are stressed causing diseases. HCMV and HIV-1 have developed multiple strategies to avoid recognition and elimination by the host's immune system. These strategies rely on viral products that mimic specific components of the host cells to prevent immune recognition of virally infected cells. In addition to viral proteins, viruses encode short non-coding RNAs (vmiRNAs) that regulate both viral and host cellular transcripts to favor viral infection and actively curtail the host's antiviral immune response. In this review, we will give an overview of the general functions of microRNAs generated by HCMV and HIV-1, their processing and interaction with the host's immune system.

20.
Cancer Discov ; 7(8): 884-899, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28446439

RESUMO

Alveolar rhabdomyosarcoma is a life-threatening myogenic cancer of children and adolescent young adults, driven primarily by the chimeric transcription factor PAX3-FOXO1. The mechanisms by which PAX3-FOXO1 dysregulates chromatin are unknown. We find PAX3-FOXO1 reprograms the cis-regulatory landscape by inducing de novo super enhancers. PAX3-FOXO1 uses super enhancers to set up autoregulatory loops in collaboration with the master transcription factors MYOG, MYOD, and MYCN. This myogenic super enhancer circuitry is consistent across cell lines and primary tumors. Cells harboring the fusion gene are selectively sensitive to small-molecule inhibition of protein targets induced by, or bound to, PAX3-FOXO1-occupied super enhancers. Furthermore, PAX3-FOXO1 recruits and requires the BET bromodomain protein BRD4 to function at super enhancers, resulting in a complete dependence on BRD4 and a significant susceptibility to BRD inhibition. These results yield insights into the epigenetic functions of PAX3-FOXO1 and reveal a specific vulnerability that can be exploited for precision therapy.Significance: PAX3-FOXO1 drives pediatric fusion-positive rhabdomyosarcoma, and its chromatin-level functions are critical to understanding its oncogenic activity. We find that PAX3-FOXO1 establishes a myoblastic super enhancer landscape and creates a profound subtype-unique dependence on BET bromodomains, the inhibition of which ablates PAX3-FOXO1 function, providing a mechanistic rationale for exploring BET inhibitors for patients bearing PAX-fusion rhabdomyosarcoma. Cancer Discov; 7(8); 884-99. ©2017 AACR.This article is highlighted in the In This Issue feature, p. 783.


Assuntos
Elementos Facilitadores Genéticos/genética , Proteínas Nucleares/genética , Proteínas de Fusão Oncogênica/genética , Fatores de Transcrição Box Pareados/genética , Rabdomiossarcoma Alveolar/tratamento farmacológico , Fatores de Transcrição/genética , Animais , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Cromatina/genética , Elementos Facilitadores Genéticos/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Epigênese Genética/genética , Feminino , Humanos , Masculino , Camundongos , Proteína MyoD/genética , Miogenina/genética , Proteína Proto-Oncogênica N-Myc/genética , Ligação Proteica/genética , Domínios Proteicos/genética , Rabdomiossarcoma Alveolar/genética , Rabdomiossarcoma Alveolar/patologia , Bibliotecas de Moléculas Pequenas/administração & dosagem , Ensaios Antitumorais Modelo de Xenoenxerto
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