RESUMEN
Our previous studies determined that elevating SOX2 in a wide range of tumor cells leads to a reversible state of tumor growth arrest. Efforts to understand how tumor cell growth is inhibited led to the discovery of a SOX2:MYC axis that is responsible for downregulating c-MYC (MYC) when SOX2 is elevated. Although we had determined that elevating SOX2 downregulates MYC transcription, the mechanism responsible was not determined. Given the challenges of targeting MYC clinically, we set out to identify how elevating SOX2 downregulates MYC transcription. In this study, we focused on the MYC promoter region and an upstream region of the MYC locus that contains a MYC super-enhancer encompassing five MYC enhancers and which is associated with several cancers. Here we report that BRD4 and p300 associate with each of the MYC enhancers in the upstream MYC super-enhancer as well as the MYC promoter region and that elevating SOX2 decreases the recruitment of BRD4 and p300 to these sites. Additionally, we determined that elevating SOX2 leads to increases in the association of SOX2 and H3K27me3 within the MYC super-enhancer and the promoter region of MYC. Importantly, we conclude that the increases in SOX2 within the MYC super-enhancer precipitate a cascade of events that culminates in the repression of MYC transcription. Together, our studies identify a novel molecular mechanism able to regulate MYC transcription in two distinctly different tumor types and provide new mechanistic insights into the molecular interrelationships between two master regulators, SOX2 and MYC, widely involved in multiple cancers.
RESUMEN
Medulloblastoma (MB) is a highly aggressive, malignant brain tumor in children with poor prognosis. Cyclin-dependent kinase 9 (CDK9), a serine-threonine kinase, is widely implicated in the control of basal gene expression by phosphorylating Serine 2 (Ser2) of the heptad repeat in the RNA Polymerase II (RNA Pol II) C-terminal domain (CTD). Although CDK9 plays a pathogenic role in various cancers, its function in MB remains unknown. Here, we show that CDK9 is highly expressed in MB tumors and increased CDK9 expression is correlated with high risk MB patients. CDK9 expression along with phospho-Ser2 RNA Pol II (pRNA Pol II ser2) and bromodomain-binding protein 4 (BRD4), which recruits CDK9, were elevated in multiple MB cell lines and in MB tumors originated spontaneously from Ptch1+/-p53-/- mice. Inhibition of CDK9 with LDC067 suppressed MB cell growth, reduced pRNA Pol II ser2 level and expression of oncogenic markers, including MYC. Moreover, LDC067 treatment synergistically sensitizes MB cells to chemotherapeutic agent cisplatin. Further, LDC067 in combination with BRD4 inhibitor decreased MB cells growth, delayed cell migration and attenuated pRNA Pol II ser2 occupancy to CCND1 and BCL2 gene promoters as revealed by chromatin immunoprecipitation assay (ChIP). Together, these findings highlight the importance of CDK9 in MB pathogenesis and suggest that it may serve as a promising therapeutic target for the treatment of MB.
Asunto(s)
Neoplasias Cerebelosas/tratamiento farmacológico , Quinasa 9 Dependiente de la Ciclina/metabolismo , Meduloblastoma/tratamiento farmacológico , Pirimidinas/farmacología , Sulfonamidas/farmacología , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Proteínas de Ciclo Celular/metabolismo , Línea Celular Tumoral , Neoplasias Cerebelosas/genética , Neoplasias Cerebelosas/patología , Cisplatino/administración & dosificación , Quinasa 9 Dependiente de la Ciclina/antagonistas & inhibidores , Resistencia a Antineoplásicos , Regulación Neoplásica de la Expresión Génica , Humanos , Meduloblastoma/genética , Meduloblastoma/patología , Ratones Mutantes , Terapia Molecular Dirigida , Neoplasias Experimentales , Pirimidinas/administración & dosificación , ARN Polimerasa II/metabolismo , Serina/metabolismo , Sulfonamidas/administración & dosificación , Factores de Transcripción/metabolismoRESUMEN
EBV(-) posttransplantation lymphoproliferative disorders (PTLDs) are rare compared with EBV(+) PTLDs, occur later after transplantation, and have a poor response to treatment. Few studies have reported EBV(-) PTLD in pediatric solid-organ transplantation recipients. We describe 5 cases of EBV(-) PTLD in recipients of combined liver and small bowel allografts ranging in age from 16 months to 7 years. EBV(-) PTLD developed 9-22 months (median, 15) after transplantation. Morphologically, the lesions ranged from atypical plasma cell hyperplasia (a term not currently included in the World Health Organization classification) to plasmacytoma like. In all cases, in situ hybridization for EBV was negative, and molecular studies demonstrated clonal IgH gene rearrangements. Protein electrophoresis showed multiple clonal paraproteins in 4 of 5 cases. In 2 cases with a donor-recipient sex mismatch, FISH cytogenetics demonstrated that the plasma cells were of mixed donor/recipient origin. One patient died before therapy. Four patients were treated with high-dose dexamethasone, and 1 patient subsequently required thalidomide. All 4 remain in remission 75-128 months (median, 86) after diagnosis. In contrast to reports of EBV(-) PTLD in adults, these plasma cell lesions occurred early after transplantation and resolved completely after minimal treatment.
Asunto(s)
Intestino Delgado/trasplante , Trasplante de Hígado/efectos adversos , Mieloma Múltiple/patología , Neoplasias de Células Plasmáticas/patología , Complicaciones Posoperatorias/patología , Niño , Preescolar , Resultado Fatal , Femenino , Enfermedades Gastrointestinales/cirugía , Herpesvirus Humano 4 , Humanos , Lactante , Masculino , Mieloma Múltiple/terapia , Neoplasias de Células Plasmáticas/terapia , Complicaciones Posoperatorias/terapia , Pronóstico , Inducción de Remisión , Trasplante HomólogoRESUMEN
Duplications of the long arm of chromosome 18 have been previously reported in patients with phenotypic findings similar to full trisomy 18. Trisomy 18 increases the risk for Wilms tumor and it is currently recommended that these patients undergo abdominal ultrasonography screening every 6 months. We report on nephroblastomatosis in a 27-month-old male with a 55 Mb duplication of chromosome 18q11.2-q23 (chr18:22693370-77982126, hg 19) and propose that the trisomy 18 tumor screening protocol could also benefit patients with large 18q duplications.
Asunto(s)
Cromosomas Humanos Par 18 , Macrosomía Fetal/genética , Duplicación de Gen , Trisomía/genética , Tumor de Wilms/genética , Preescolar , Cromosomas Humanos Par 18/genética , Humanos , Masculino , Síndrome de la Trisomía 18RESUMEN
While better management of loco-regional prostate cancer (PC) has greatly improved survival, advanced PC remains a major cause of cancer deaths. Identification of novel targetable pathways that contribute to tumor progression in PC could open new therapeutic options. The di-ganglioside GD2 is a target of FDA-approved antibody therapies in neuroblastoma, but the role of GD2 in PC is unexplored. Here, we show that GD2 is expressed in a small subpopulation of PC cells in a subset of patients and a higher proportion of metastatic tumors. Variable levels of cell surface GD2 expression were seen on many PC cell lines, and the expression was highly upregulated by experimental induction of lineage progression or enzalutamide resistance in CRPC cell models. GD2high cell fraction was enriched upon growth of PC cells as tumorspheres and GD2high fraction was enriched in tumorsphere-forming ability. CRISPR-Cas9 knockout (KO) of the rate-limiting GD2 biosynthetic enzyme GD3 Synthase (GD3S) in GD2high CRPC cell models markedly impaired the in vitro oncogenic traits and growth as bone-implanted xenograft tumors and reduced the cancer stem cell and epithelial-mesenchymal transition marker expression. Our results support the potential role of GD3S and its product GD2 in promoting PC tumorigenesis by maintaining cancer stem cells and suggest the potential for GD2 targeting in advanced PC.
Asunto(s)
Carcinogénesis , Gangliósidos , Células Madre Neoplásicas , Sialiltransferasas , Masculino , Humanos , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Sialiltransferasas/metabolismo , Sialiltransferasas/genética , Animales , Línea Celular Tumoral , Gangliósidos/metabolismo , Ratones , Carcinogénesis/genética , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , Feniltiohidantoína/farmacología , Resistencia a Antineoplásicos/genética , Regulación Neoplásica de la Expresión Génica , Benzamidas/farmacología , Nitrilos/farmacologíaRESUMEN
Medulloblastoma (MB) is a malignant pediatric brain tumor which shows upregulation of MYC and sonic hedgehog (SHH) signaling. SHH inhibitors face acquired resistance, which is a major cause of relapse. Further, direct MYC oncogene inhibition is challenging, inhibition of MYC upstream insulin-like growth factor/ phosphatidylinositol-4,5-bisphosphate 3-kinase (IGF/PI3K) is a promising alternative. While PI3K inhibition activates resistance mechanisms, simultaneous inhibition of bromodomain-containing protein 4 (BRD4) and PI3K can overcome resistance. We synthesized a new molecule 8-(2,3-dihydrobenzo[b] [1, 4] dioxin-6-yl)-2-morpholino-4H-chromen-4-one (MDP5) that targets both BRD4 and PI3K pathways. We used X-ray crystal structures and a molecular modeling approach to confirm the interactions between MDP5 with bromo domains (BDs) from both BRD2 and BRD4, and molecular modeling for PI3K binding. MDP5 was shown to inhibit target pathways and MB cell growth in vitro and in vivo. MDP5 showed higher potency in DAOY cells (IC50 5.5 µM) compared to SF2523 (IC50 12.6 µM), and its IC50 values in HD-MB03 cells were like SF2523. Treatment of MB cells with MDP5 significantly decreased colony formation, increased apoptosis, and halted cell cycle progression. Further, MDP5 was well tolerated in NSG mice bearing either xenograft or orthotopic MB tumors at the dose of 20 mg/kg, and significantly reduced tumor growth and prolonged animal survival.
Asunto(s)
Neoplasias Encefálicas , Neoplasias Cerebelosas , Meduloblastoma , Humanos , Ratones , Animales , Factores de Transcripción , Proteínas Nucleares , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Hedgehog , Transducción de Señal , Proliferación Celular , Línea Celular Tumoral , Proteínas de Ciclo CelularRESUMEN
With nearly all cancer deaths a result of metastasis, elucidating novel pro-metastatic cellular adaptations could provide new therapeutic targets. Here, we show that overexpression of the EPS15-Homology Domain-containing 2 (EHD2) protein in a large subset of breast cancers (BCs), especially the triple-negative (TNBC) and HER2+ subtypes, correlates with shorter patient survival. The mRNAs for EHD2 and Caveolin-1/2, structural components of caveolae, show co-overexpression across breast tumors, predicting shorter survival in basal-like BC. EHD2 shRNA knockdown and CRISPR-Cas9 knockout with mouse Ehd2 rescue, in TNBC cell line models demonstrate a major positive role of EHD2 in promoting tumorigenesis and metastasis. Mechanistically, we link these roles of EHD2 to store-operated calcium entry (SOCE), with EHD2-dependent stabilization of plasma membrane caveolae ensuring high cell surface expression of the SOCE-linked calcium channel Orai1. The novel EHD2-SOCE oncogenic axis represents a potential therapeutic target in EHD2- and CAV1/2-overexpressing BC.
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Neoplasias de la Mama Triple Negativas , Humanos , Ratones , Animales , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/metabolismo , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Calcio/metabolismo , Membrana Celular/metabolismo , Carcinogénesis/genética , Carcinogénesis/metabolismo , Transformación Celular Neoplásica/metabolismo , Molécula de Interacción Estromal 1/metabolismoRESUMEN
Overexpression of EPS15 Homology Domain containing 1 (EHD1) has been linked to tumorigenesis but whether its core function as a regulator of intracellular traffic of cell surface receptors plays a role in oncogenesis remains unknown. We establish that EHD1 is overexpressed in Ewing sarcoma (EWS), with high EHD mRNA expression specifying shorter patient survival. ShRNA and CRISPR-knockout with mouse Ehd1 rescue established a requirement of EHD1 for tumorigenesis and metastasis. RTK antibody arrays identified the IGF-1R as a target of EHD1 regulation in EWS. Mechanistically, we demonstrate a requirement of EHD1 for endocytic recycling and Golgi to plasma membrane traffic of IGF-1R to maintain its surface expression and downstream signaling. Conversely, EHD1 overexpression-dependent exaggerated oncogenic traits require IGF-1R expression and kinase activity. Our findings define the RTK traffic regulation as a proximal mechanism of EHD1 overexpression-dependent oncogenesis that impinges on IGF-1R in EWS, supporting the potential of IGF-1R and EHD1 co-targeting.
RESUMEN
Overexpression of the EPS15 Homology Domain containing 1 (EHD1) protein has been linked to tumorigenesis but whether its core function as a regulator of intracellular traffic of cell surface receptors plays a role in oncogenesis remains unknown. We establish that EHD1 is overexpressed in Ewing sarcoma (EWS), with high EHD1 mRNA expression specifying shorter patient survival. ShRNA-knockdown and CRISPR-knockout with mouse Ehd1 rescue established a requirement of EHD1 for tumorigenesis and metastasis. RTK antibody arrays identified IGF-1R as a target of EHD1 regulation in EWS. Mechanistically, we demonstrate a requirement of EHD1 for endocytic recycling and Golgi to plasma membrane traffic of IGF-1R to maintain its surface expression and downstream signaling. Conversely, EHD1 overexpression-dependent exaggerated oncogenic traits require IGF-1R expression and kinase activity. Our findings define the RTK traffic regulation as a proximal mechanism of EHD1 overexpression-dependent oncogenesis that impinges on IGF-1R in EWS, supporting the potential of IGF-1R and EHD1 co-targeting.
Asunto(s)
Sarcoma de Ewing , Ratones , Animales , Sarcoma de Ewing/genética , Sarcoma de Ewing/metabolismo , Sarcoma de Ewing/patología , Receptor IGF Tipo 1/genética , Receptor IGF Tipo 1/metabolismo , Membrana Celular/metabolismo , Transducción de Señal/fisiología , Carcinogénesis/genética , Carcinogénesis/metabolismo , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/metabolismoRESUMEN
In this study, we identify USP1 as a transcriptional target of EWS::FLI1 and demonstrate the requisite function of USP1 in Ewing sarcoma (EWS) cell survival in response to endogenous replication stress. EWS::FLI1 oncogenic transcription factor drives most EWS, a pediatric bone cancer. EWS cells display elevated levels of R-loops and replication stress. The mechanism by which EWS cells override activation of apoptosis or cellular senescence in response to increased replication stress is not known. We show that USP1 is overexpressed in EWS and EWS::FLI1 regulates USP1 transcript levels. USP1 knockdown or inhibition arrests EWS cell growth and induces cell death by apoptosis. Mechanistically, USP1 regulates Survivin (BIRC5/API4) protein stability and the activation of caspase-9 and caspase-3/7 in response to endogenous replication stress. Notably, USP1 inhibition sensitizes cells to doxorubicin and etoposide treatment. Together, our study demonstrates that USP1 is regulated by EWS::FLI1, the USP1-Survivin axis promotes EWS cell survival, and USP1 inhibition sensitizes cells to standard of care chemotherapy. IMPLICATIONS: High USP1 and replication stress levels driven by EWS::FLI1 transcription factor in EWS are vulnerabilities that can be exploited to improve existing treatment avenues and overcome drug resistance.
Asunto(s)
Sarcoma de Ewing , Humanos , Niño , Sarcoma de Ewing/metabolismo , Proteína Proto-Oncogénica c-fli-1/genética , Proteína Proto-Oncogénica c-fli-1/metabolismo , Survivin/genética , Survivin/metabolismo , Proteína EWS de Unión a ARN/genética , Proteína EWS de Unión a ARN/metabolismo , Línea Celular Tumoral , Proteínas de Fusión Oncogénica/genética , Proteínas de Fusión Oncogénica/metabolismo , Regulación Neoplásica de la Expresión Génica , Proteasas Ubiquitina-Específicas/metabolismoRESUMEN
While better management of loco-regional prostate cancer (PC) has greatly improved survival, advanced PC remains a major cause of cancer deaths. Identification of novel, targetable, pathways that contribute to tumor progression of PC could open new therapeutic options. The di-ganglioside GD2 is a target of FDA-approved antibody therapies in neuroblastoma, but the role of GD2 in PC has been only little explored. Here, we show that GD2 is expressed on a small subpopulation of PC cells in a subset of patients, especially in metastatic PC. Variable levels of cell surface GD2 expression are seen in most PC cell lines, and the expression is highly upregulated by experimental induction of lineage progression or enzalutamide resistance in CRPC cell models. GD2high cell fraction is enriched upon growth of PC cells as tumorspheres and GD2high fraction is enriched in tumorsphere growth. CRISPR-Cas9 knockout (KO) of the rate-limiting GD2 biosynthetic enzyme GD3 Synthase (GD3S) in GD2-high CRPC cell models led to marked impairment of their in vitro oncogenic traits, reduced cancer stem cell (CSC) and epithelial-mesenchymal transition (EMT) marker expression and growth as bone-implanted xenograft tumors. Our results support the potential role of GD3S and its product GD2 in promoting PC tumorigenesis by maintaining cancer stem cells and suggest the potential for GD2 targeting in advanced PC.
RESUMEN
Our body keeps separating the toxic chemicals in the blood from the brain. A significant number of drugs do not enter the central nervous system (CNS) due to the blood-brain barrier (BBB). Certain diseases, such as tumor growth and stroke, are known to increase the permeability of the BBB. However, the heterogeneity of this permeation makes it difficult and unpredictable to transport drugs to the brain. In recent years, research has been directed toward increasing drug penetration inside the brain, and nanomedicine has emerged as a promising approach. Active targeting requires one or more specific ligands on the surface of nanoparticles (NPs), which brain endothelial cells (ECs) recognize, allowing controlled drug delivery compared to conventional targeting strategies. This review highlights the mechanistic insights about different cell types contributing to the development and maintenance of the BBB and summarizes the recent advancement in brain-specific NPs for different pathological conditions. Furthermore, fundamental properties of brain-targeted NPs will be discussed, and the standard lesion features classified by neurological pathology are summarized.
Asunto(s)
Células Endoteliales , Nanopartículas , Barrera Hematoencefálica/metabolismo , Encéfalo/metabolismo , Sistemas de Liberación de Medicamentos , Células Endoteliales/metabolismo , Nanomedicina , Nanopartículas/química , Preparaciones Farmacéuticas/metabolismoRESUMEN
The incidence of pediatric cancers is rising steadily across the world, along with the challenges in understanding the molecular mechanisms and devising effective therapeutic strategies. Pediatric cancers are presented with diverse molecular characteristics and more distinct subtypes when compared to adult cancers. Recent studies on the genomic landscape of pediatric cancers using next-generation sequencing (NGS) approaches have redefined this field by providing better subtype characterization and novel actionable targets. Since early identification and personalized treatment strategies influence therapeutic outcomes, survival, and quality of life in pediatric cancer patients, the quest for actionable biomarkers is of great value in this field. Fusion genes that are prevalent and recurrent in several pediatric cancers are ideally suited in this context due to their disease-specific occurrence. In this review, we explore the current status of fusion genes in pediatric cancer subtypes and their use as biomarkers for diagnosis and personalized therapy. We discuss the technological advancements made in recent years in NGS sequencing and their impact on fusion detection algorithms that have revolutionized this field. Finally, we also discuss the advantages of pairing liquid biopsy protocols for fusion detection and their eventual use in diagnosis and treatment monitoring.
Asunto(s)
Antineoplásicos/uso terapéutico , Biomarcadores de Tumor/genética , Detección Precoz del Cáncer/métodos , Neoplasias/diagnóstico , Proteínas de Fusión Oncogénica/genética , Antineoplásicos/farmacología , Biomarcadores de Tumor/antagonistas & inhibidores , Biomarcadores de Tumor/sangre , Niño , ADN Tumoral Circulante/sangre , ADN Tumoral Circulante/genética , Monitoreo de Drogas/métodos , Pruebas Genéticas/métodos , Genómica/métodos , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Biopsia Líquida/métodos , Neoplasias/sangre , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Proteínas de Fusión Oncogénica/antagonistas & inhibidores , Proteínas de Fusión Oncogénica/sangre , Medicina de Precisión/métodos , Resultado del TratamientoRESUMEN
Immunotherapy has emerged at the forefront of cancer treatment. Checkpoint inhibitor pembrolizumab (KEYTRUDA), a chimeric antibody which targets programmed cell death protein 1 (PD-1), has been approved by the Food and Drug Administration (FDA) for use in pediatric patients with relapsed or refractory classical Hodgkin's lymphoma. However, there is currently no published data regarding the effects of pembrolizumab on the ovary of female pediatric patients. In this study, prepubertal immunocompetent and immunodeficient female mice were injected with pembrolizumab or anti-mouse PD-1 antibody. The number of primordial follicles significantly decreased post-injection of both pembrolizumab and anti-mouse PD-1 antibody in immunocompetent mice. However, no changes in follicle numbers were observed in immunodeficient nude mice. Superovulation test and vaginal opening experiments suggest that there is no difference in the number of cumulus-oocyte complexes (COCs) and the timing of puberty onset between the control and anti-mouse PD-1 antibody treatment groups, indicating that there is no effect on short-term fertility. Elevation of pro-inflammatory cytokine TNF-α following COX-2 upregulation was observed in the ovary. CD3+ T-cell infiltration was detected within some ovarian follicles and between stromal cells of the ovaries in mice following treatment with anti-mouse PD-1 antibody. Thus, PD-1 immune checkpoint blockade affects the ovarian reserve through a mechanism possibly involving inflammation following CD3+ T-cell infiltration.
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Anticuerpos Monoclonales Humanizados/farmacología , Folículo Ovárico/efectos de los fármacos , Maduración Sexual/efectos de los fármacos , Animales , Animales Recién Nacidos , Anticuerpos Monoclonales Humanizados/efectos adversos , Antineoplásicos Inmunológicos/efectos adversos , Antineoplásicos Inmunológicos/farmacología , Recuento de Células , Femenino , Inhibidores de Puntos de Control Inmunológico/efectos adversos , Inhibidores de Puntos de Control Inmunológico/farmacología , Infertilidad Femenina/inducido químicamente , Infertilidad Femenina/patología , Ratones , Ratones Desnudos , Oocitos/citología , Oocitos/efectos de los fármacos , Reserva Ovárica/efectos de los fármacos , Ovario/efectos de los fármacos , Ovario/fisiología , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Receptor de Muerte Celular Programada 1/inmunologíaRESUMEN
Chemoresistance and inadequate therapeutics transport across the blood brain barrier (BBB) remain the major barriers to treating medulloblastoma (MB). Hedgehog (Hh) and IGF/PI3K pathways regulate tumor cell proliferation and resistance in MB. Current Hh inhibitors are effective initially to treat SHH-MB but acquire resistance. Herein, we showed that Hh inhibitor MDB5 and BRD4/PI3K dual inhibitor SF2523 synergistically inhibited the proliferation of DAOY and HD-MB03 cells when used in combination. Treatment of these MB cells with the combination of MDB5 and SF2523 significantly decreased colony formation and expression of MYCN, p-AKT, and cyclin D1 but significantly increased in Bax expression, compared to individual drugs. We used our previously reported copolymer mPEG-b-PCC-g-DC copolymer, which showed 8.7 ± 1.0 and 6.5 ± 0.1% loading for MDB5 and SF2523 when formulated into nanoparticles (NPs). There was sustained drug release from NPs, wherein 100% of MDB5 was released in 50 h, but only 60% of SF2523 was released in 80 h. Targeted NPs prepared by mixing 30:70 ratio of COG-133-PEG-b-PBC and mPEG-b-PCC-g-DC copolymer delivered a significantly higher drug concentration in the cerebellum at 6 and 24h after intravenous injection into orthotopic SHH-MB tumor-bearing NSG mice. Moreover, systemic administration of COG-133-NPs loaded with MDB5 and SF2523 resulted in decreased tumor burden compared to non-targeted drug-loaded NPs, without any hepatic toxicity. In conclusion, our nanomedicine of MDB5 and SF2523 offers a novel therapeutic strategy to treat chemoresistant MB.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias Cerebelosas , Meduloblastoma , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Derivados del Benceno , Línea Celular Tumoral , Neoplasias Cerebelosas/tratamiento farmacológico , Neoplasias Cerebelosas/genética , Sinergismo Farmacológico , Proteínas Hedgehog , Meduloblastoma/tratamiento farmacológico , Meduloblastoma/genética , Ratones , Morfolinas , Nanomedicina , Proteínas Nucleares , Fosfatidilinositol 3-Quinasas , Piranos , Piridinas , Factores de TranscripciónRESUMEN
Medulloblastoma (MB) is a malignant pediatric brain tumor with a poor prognosis. Post-surgical radiation and cisplatin-based chemotherapy have been a mainstay of treatment, which often leads to substantial neurocognitive impairments and morbidity, highlighting the need for a novel therapeutic target to enhance the sensitivity of MB tumors to cytotoxic therapies. We performed a comprehensive study using a cohort of 71 MB patients' samples and pediatric MB cell lines and found that MB tumors have elevated levels of nucleosome remodeling FACT (FAcilitates Chromatin Transcription) complex and DNA repair enzyme AP-endonuclease1 (APE1). FACT interacts with APE1 and facilitates recruitment and acetylation of APE1 to promote repair of radiation and cisplatin-induced DNA damage. Further, levels of FACT and acetylated APE1 both are correlate strongly with MB patients' survival. Targeting FACT complex with CBL0137 inhibits DNA repair and alters expression of a subset of genes, and significantly improves the potency of cisplatin and radiation in vitro and in MB xenograft. Notably, combination of CBL0137 and cisplatin significantly suppressed MB tumor growth in an intracranial orthotopic xenograft model. We conclude that FACT complex promotes chemo-radiation resistance in MB, and FACT inhibitor CBL0137 can be used as a chemo-radiation sensitizer to augment treatment efficacy and reduce therapy-related toxicity in high-risk pediatric patients.
Asunto(s)
Cisplatino/administración & dosificación , ADN-(Sitio Apurínico o Apirimidínico) Liasa/genética , Proteínas de Unión al ADN/genética , Proteínas del Grupo de Alta Movilidad/genética , Meduloblastoma/tratamiento farmacológico , Factores de Elongación Transcripcional/genética , Adolescente , Adulto , Animales , Carbazoles/administración & dosificación , Carbazoles/efectos adversos , Niño , Preescolar , Cisplatino/efectos adversos , Daño del ADN/efectos de los fármacos , Daño del ADN/efectos de la radiación , Reparación del ADN/efectos de los fármacos , Reparación del ADN/efectos de la radiación , Proteínas de Unión al ADN/antagonistas & inhibidores , Resistencia a Antineoplásicos/efectos de los fármacos , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de la radiación , Xenoinjertos , Proteínas del Grupo de Alta Movilidad/antagonistas & inhibidores , Chaperonas de Histonas/genética , Humanos , Masculino , Meduloblastoma/genética , Meduloblastoma/patología , Meduloblastoma/radioterapia , Ratones , Factores de Elongación Transcripcional/antagonistas & inhibidores , Adulto JovenRESUMEN
High risk neuroblastoma often recurs, even with aggressive treatments. Clinical evidence suggests that proliferative activities are predictive of poor outcomes. This report describes syntheses, characterization, and biological properties of theranostic guanidines that target norepinephrine transporter and undergo intracellular processing, and subsequently their catabolites are efficiently incorporated into DNA of proliferating neuroblastoma cells. Radioactive guanidines are synthesized from 5-radioiodo-2'-deoxyuridine, a molecular radiotherapy platform with clinically proven minimal toxicities and DNA-targeting properties. The transport of radioactive guanidines into neuroblastoma cells is active as indicated by the competitive suppression of cellular uptake by meta-iodobenzylguanidine. The rate of intracellular processing and DNA uptake is influenced by the agent's catabolic stability and cell population doubling times. The radiotoxicity is directly proportional to DNA uptake and duration of exposure. Biodistribution of 5-[125I]iodo-3'-O-(ε-guanidinohexanoyl)-2'-deoxyuridine in a mouse neuroblastoma model shows significant tumor retention of radioactivity. Neuroblastoma xenografts regress in response to the clinically achievable doses of this agent.
Asunto(s)
ADN/metabolismo , Sistemas de Liberación de Medicamentos/métodos , Guanidinas/metabolismo , Proteínas de Transporte de Noradrenalina a través de la Membrana Plasmática/metabolismo , Nanomedicina Teranóstica/métodos , Animales , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Femenino , Guanidinas/administración & dosificación , Humanos , Masculino , Ratones , Ratones Desnudos , Ensayos Antitumor por Modelo de Xenoinjerto/métodosRESUMEN
Treatment of medulloblastoma (MB) is challenging due to diverse genetic make-up, chemoresistance and inefficient drug transport across the blood brain barrier (BBB). Since hedgehog (Hh) signaling regulates cancer cell proliferation and tumorigenicity, Hh inhibitors have the potential to treat sonic Hh driven MB (SHH-MB), but their repeated use develops chemoresistance due to mutations in smoothened (SMO). Herein, we aimed to overcome these problems by modulating GLI transcription using JQ1, which is a small molecule BRD4 inhibitor. JQ1 inhibited HD-MB03 and DAOY cell proliferation, with the IC50 of 402 and 4220 nM, respectively. JQ1 inhibited colony formation, but increased apoptosis in HD-MB03 and DAOY cells. Western blot analysis confirmed significant inhibition of GLI1 and c-MYC protein expression in DAOY and HD-MB03 cells, respectively. JQ1 was encapsulated into apolipoprotein (ApoE) mimetic peptide decorated nanoparticles (ApoE-NPs), with the mean particle size of 64 nm and drug loading of 10% (w/w). ApoE-NPs increased JQ1 concentration in the tumor by 5 and 8 folds at 6 and 24 h after systemic administration into orthotopic MB tumor bearing NSG mice compared to non-targeted JQ1 loaded NPs. Although there was also modest increase in JQ1 delivery to the liver, there was no hepatotoxicity as evidenced by H&E staining and little increase in serum ALT and AST after treatment with JQ1 loaded ApoE-NPs. There was also significant decrease in the orthotopic MB tumor burden after systemic administration of JQ1 loaded ApoE- NPs at the dose of 10 mg/kg every 3rd day for a total of 8 injections. In conclusion, JQ1 loaded NPs have the potential to treat Group 3 and SHH driven MB in mice.
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Neoplasias Cerebelosas , Meduloblastoma , Nanopartículas , Proteínas Nucleares/antagonistas & inhibidores , Factores de Transcripción/antagonistas & inhibidores , Animales , Apolipoproteínas , Línea Celular Tumoral , Proliferación Celular , Neoplasias Cerebelosas/tratamiento farmacológico , Proteínas Hedgehog , Meduloblastoma/tratamiento farmacológico , RatonesRESUMEN
Of the four primary subgroups of medulloblastoma, the most frequent cytogenetic abnormality, i17q, distinguishes Groups 3 and 4 which carry the highest mortality; haploinsufficiency of 17p13.3 is a marker for particularly poor prognosis. At the terminal end of this locus lies miR-1253, a brain-enriched microRNA that regulates bone morphogenic proteins during cerebellar development. We hypothesized miR-1253 confers novel tumor-suppressive properties in medulloblastoma. Using two different cohorts of medulloblastoma samples, we first studied the expression and methylation profiles of miR-1253. We then explored the anti-tumorigenic properties of miR-1253, in parallel with a biochemical analysis of apoptosis and proliferation, and isolated oncogenic targets using high-throughput screening. Deregulation of miR-1253 expression was noted, both in medulloblastoma clinical samples and cell lines, by epigenetic silencing via hypermethylation; specific de-methylation of miR-1253 not only resulted in rapid recovery of expression but also a sharp decline in tumor cell proliferation and target gene expression. Expression restoration also led to a reduction in tumor cell virulence, concomitant with activation of apoptotic pathways, cell cycle arrest and reduction of markers of proliferation. We identified two oncogenic targets of miR-1253, CDK6 and CD276, whose silencing replicated the negative trophic effects of miR-1253. These data reveal novel tumor-suppressive properties for miR-1253, i.e., (i) loss of expression via epigenetic silencing; (ii) negative trophic effects on tumor aggressiveness; and (iii) downregulation of oncogenic targets.
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Antígenos B7/genética , Neoplasias Cerebelosas/patología , Quinasa 6 Dependiente de la Ciclina/genética , Regulación Neoplásica de la Expresión Génica/genética , Meduloblastoma/patología , MicroARNs/genética , Proliferación Celular/genética , Neoplasias Cerebelosas/genética , Humanos , Meduloblastoma/genéticaRESUMEN
Neuroblastoma is the most commonly diagnosed extracranial solid tumor in children. The patients with aggressive metastatic disease or refractory/relapsed neuroblastoma currently face a dismally low chance of survival. Thus, there is a great need for more effective therapies for this illness. In previous studies, we, as well as others, showed that the immune cell chemoattractant C-C motif chemokine ligand 21 (CCL21) is effective as an intratumoral therapy able to slow the growth of cancers. In this current study, we developed and tested an injectable, slow-release, uniform, and optimally loaded alginate nanoformulation of CCL21 as a means to provide prolonged intratumoral treatment. The alginate-nanoformulated CCL21, when injected intratumorally into mice bearing neuroblastoma lesions, significantly prolonged survival and decreased the tumor growth rate compared to CCL21 alone, empty nanoparticles, or buffer. Notably, we also observed complete tumor clearance and subsequent full protection against tumor rechallenge in 33% of nanoformulated CCL21-treated mice. Greater intratumoral presence of nanoformulated CCL21, compared to free CCL21, at days 1 and 2 after treatment ended was confirmed through fluorescent labeling and tracking. Nanoformulated CCL21-treated tumors exhibited a general pattern of prolonged increases in anti-tumor cytokines and relatively lower levels of pro-tumor cytokines in comparison to tumors treated with CCL21 alone or buffer only. Thus, this novel nanoformulation of CCL21 is an effective treatment for neuroblastoma, and may have potential for the delivery of CCL21 to other types of solid tumors in the future and as a slow-release delivery modality for other immunotherapies.