RESUMO
The tumor-suppressor breast cancer 1 (BRCA1) in complex with BRCA1-associated really interesting new gene (RING) domain 1 (BARD1) is a RING-type ubiquitin E3 ligase that modifies nucleosomal histone and other substrates. The importance of BRCA1-BARD1 E3 activity in tumor suppression remains highly controversial, mainly stemming from studying mutant ligase-deficient BRCA1-BARD1 species that we show here still retain significant ligase activity. Using full-length BRCA1-BARD1, we establish robust BRCA1-BARD1-mediated ubiquitylation with specificity, uncover multiple modes of activity modulation, and construct a truly ligase-null variant and a variant specifically impaired in targeting nucleosomal histones. Cells expressing either of these BRCA1-BARD1 separation-of-function alleles are hypersensitive to DNA-damaging agents. Furthermore, we demonstrate that BRCA1-BARD1 ligase is not only required for DNA resection during homology-directed repair (HDR) but also contributes to later stages for HDR completion. Altogether, our findings reveal crucial, previously unrecognized roles of BRCA1-BARD1 ligase activity in genome repair via HDR, settle prior controversies regarding BRCA1-BARD1 ligase functions, and catalyze new efforts to uncover substrates related to tumor suppression.
Assuntos
Neoplasias , Proteínas Supressoras de Tumor , Humanos , Proteínas Supressoras de Tumor/metabolismo , Proteína BRCA1/metabolismo , Ubiquitinação , Histonas/genética , Histonas/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Reparo de DNA por Recombinação , DNA , Reparo do DNARESUMO
The purpose of this study is to further validate the utility of our previously developed CNN in an alternative small animal model of BM through transfer learning. Unlike the glioma model, the BM mouse model develops multifocal intracranial metastases, including both contrast enhancing and non-enhancing lesions on DCE MRI, thus serving as an excellent brain tumor model to study tumor vascular permeability. Here, we conducted transfer learning by transferring the previously trained GBM CNN to DCE MRI datasets of BM mice. The CNN was re-trained to learn about the relationship between BM DCE images and target permeability maps extracted from the Extended Tofts Model (ETM). The transferred network was found to accurately predict BM permeability and presented with excellent spatial correlation with the target ETM PK maps. The CNN model was further tested in another cohort of BM mice treated with WBRT to assess vascular permeability changes induced via radiotherapy. The CNN detected significantly increased permeability parameter Ktrans in WBRT-treated tumors (p < 0.01), which was in good agreement with the target ETM PK maps. In conclusion, the proposed CNN can serve as an efficient and accurate tool for characterizing vascular permeability and treatment responses in small animal brain tumor models.
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Despite therapeutic advancements, the prognosis of locally advanced non-small cell lung cancer (LANSCLC), which has invaded multiple lobes or the other lung and intrapulmonary lymph nodes, remains poor. The emergence of immunotherapy with immune checkpoint blockade (ICB) is transforming cancer treatment. However, only a fraction of lung cancer patients benefit from ICB. Significant clinical evidence suggests that the proinflammatory tumor microenvironment (TME) and programmed death-ligand 1 (PD-L1) expression correlate positively with response to the PD-1/PD-L1 blockade. We report here a liposomal nanoparticle loaded with cyclic dinucleotide and aerosolized (AeroNP-CDN) for inhalation delivery to deep-seated lung tumors and target CDN to activate stimulators of interferon (IFN) genes in macrophages and dendritic cells (DCs). Using a mouse model that recapitulates the clinical LANSCLC, we show that AeroNP-CDN efficiently mitigates the immunosuppressive TME by reprogramming tumor-associated macrophage from the M2 to M1 phenotype, activating DCs for effective tumor antigen presentation and increasing tumor-infiltrating CD8+ T cells for adaptive anticancer immunity. Intriguingly, activation of interferons by AeroNP-CDN also led to increased PD-L1 expression in lung tumors, which, however, set a stage for response to anti-PD-L1 treatment. Indeed, anti-PD-L1 antibody-mediated blockade of IFNs-induced immune inhibitory PD-1/PD-L1 signaling further prolonged the survival of the LANSCLC-bearing mice. Importantly, AeroNP-CDN alone or combination immunotherapy was safe without local or systemic immunotoxicity. In conclusion, this study demonstrates a potential nano-immunotherapy strategy for LANSCLC, and mechanistic insights into the evolution of adaptive immune resistance provide a rational combination immunotherapy to overcome it.
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The epidermal growth factor receptor (EGFR) is a prime oncogene that is frequently amplified in glioblastomas. Here we demonstrate a new tumour-suppressive function of EGFR in EGFR-amplified glioblastomas regulated by EGFR ligands. Constitutive EGFR signalling promotes invasion via activation of a TAB1-TAK1-NF-κB-EMP1 pathway, resulting in large tumours and decreased survival in orthotopic models. Ligand-activated EGFR promotes proliferation and surprisingly suppresses invasion by upregulating BIN3, which inhibits a DOCK7-regulated Rho GTPase pathway, resulting in small hyperproliferating non-invasive tumours and improved survival. Data from The Cancer Genome Atlas reveal that in EGFR-amplified glioblastomas, a low level of EGFR ligands confers a worse prognosis, whereas a high level of EGFR ligands confers an improved prognosis. Thus, increased EGFR ligand levels shift the role of EGFR from oncogene to tumour suppressor in EGFR-amplified glioblastomas by suppressing invasion. The tumour-suppressive function of EGFR can be activated therapeutically using tofacitinib, which suppresses invasion by increasing EGFR ligand levels and upregulating BIN3.
Assuntos
Glioblastoma , Proteínas dos Microfilamentos/metabolismo , Linhagem Celular Tumoral , Receptores ErbB/genética , Receptores ErbB/metabolismo , Glioblastoma/metabolismo , Humanos , Ligantes , Oncogenes/genética , Regulação para CimaRESUMO
Malignant pleural effusion (MPE) is indicative of terminal malignancy with a uniformly fatal prognosis. Often, two distinct compartments of tumour microenvironment, the effusion and disseminated pleural tumours, co-exist in the pleural cavity, presenting a major challenge for therapeutic interventions and drug delivery. Clinical evidence suggests that MPE comprises abundant tumour-associated myeloid cells with the tumour-promoting phenotype, impairing antitumour immunity. Here we developed a liposomal nanoparticle loaded with cyclic dinucleotide (LNP-CDN) for targeted activation of stimulators of interferon genes signalling in macrophages and dendritic cells and showed that, on intrapleural administration, they induce drastic changes in the transcriptional landscape in MPE, mitigating the immune cold MPE in both effusion and pleural tumours. Moreover, combination immunotherapy with blockade of programmed death ligand 1 potently reduced MPE volume and inhibited tumour growth not only in the pleural cavity but also in the lung parenchyma, conferring significantly prolonged survival of MPE-bearing mice. Furthermore, the LNP-CDN-induced immunological effects were also observed with clinical MPE samples, suggesting the potential of intrapleural LNP-CDN for clinical MPE immunotherapy.
Assuntos
Antígeno B7-H1/farmacologia , Sistemas de Liberação de Medicamentos , Nanopartículas/química , Derrame Pleural Maligno/tratamento farmacológico , Imunidade Adaptativa/efeitos dos fármacos , Animais , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/química , Antígeno B7-H1/imunologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Células Dendríticas/efeitos dos fármacos , Humanos , Inibidores de Checkpoint Imunológico/química , Inibidores de Checkpoint Imunológico/farmacologia , Imunidade Inata/efeitos dos fármacos , Imunoterapia , Interferons/genética , Camundongos , Nanopartículas/uso terapêutico , Cavidade Pleural/efeitos dos fármacos , Cavidade Pleural/imunologia , Cavidade Pleural/patologia , Derrame Pleural Maligno/genética , Derrame Pleural Maligno/imunologia , Derrame Pleural Maligno/patologia , Microambiente Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Inhibition of RTK pathways in cancer triggers an adaptive response that promotes therapeutic resistance. Because the adaptive response is multifaceted, the optimal approach to blunting it remains undetermined. TNF upregulation is a biologically significant response to EGFR inhibition in NSCLC. Here, we compared a specific TNF inhibitor (etanercept) to thalidomide and prednisone, two drugs that block TNF and also other inflammatory pathways. Prednisone is significantly more effective in suppressing EGFR inhibition-induced inflammatory signals. Remarkably, prednisone induces a shutdown of bypass RTK signaling and inhibits key resistance signals such as STAT3, YAP and TNF-NF-κB. Combined with EGFR inhibition, prednisone is significantly superior to etanercept or thalidomide in durably suppressing tumor growth in multiple mouse models, indicating that a broad suppression of adaptive signals is more effective than blocking a single component. We identify prednisone as a drug that can effectively inhibit adaptive resistance with acceptable toxicity in NSCLC and other cancers.
Assuntos
Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Glucocorticoides/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Transdução de Sinais/efeitos dos fármacos , Células A549 , Animais , Carcinoma Pulmonar de Células não Pequenas , Citocinas/metabolismo , Modelos Animais de Doenças , Receptores ErbB/efeitos dos fármacos , Feminino , Humanos , Neoplasias Pulmonares , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Camundongos Transgênicos , Prednisona , Fator de Transcrição STAT3/metabolismo , Talidomida , Inibidores do Fator de Necrose Tumoral , Regulação para CimaRESUMO
Glioblastomas (GBM) are routinely treated with ionizing radiation (IR) but inevitably recur and develop therapy resistance. During treatment, the tissue surrounding tumors is also irradiated. IR potently induces senescence, and senescent stromal cells can promote the growth of neighboring tumor cells by secreting factors that create a senescence-associated secretory phenotype (SASP). Here, we carried out transcriptomic and tumorigenicity analyses in irradiated mouse brains to elucidate how radiotherapy-induced senescence of non-neoplastic brain cells promotes tumor growth. Following cranial irradiation, widespread senescence in the brain occurred, with the astrocytic population being particularly susceptible. Irradiated brains showed an altered transcriptomic profile characterized by upregulation of CDKN1A (p21), a key enforcer of senescence, and several SASP factors, including HGF, the ligand of the receptor tyrosine kinase (RTK) Met. Preirradiation of mouse brains increased Met-driven growth and invasiveness of orthotopically implanted glioma cells. Importantly, irradiated p21-/- mouse brains did not exhibit senescence and consequently failed to promote tumor growth. Senescent astrocytes secreted HGF to activate Met in glioma cells and to promote their migration and invasion in vitro, which could be blocked by HGF-neutralizing antibodies or the Met inhibitor crizotinib. Crizotinib also slowed the growth of glioma cells implanted in preirradiated brains. Treatment with the senolytic drug ABT-263 (navitoclax) selectively killed senescent astrocytes in vivo, significantly attenuating growth of glioma cells implanted in preirradiated brains. These results indicate that SASP factors in the irradiated tumor microenvironment drive GBM growth via RTK activation, underscoring the potential utility of adjuvant senolytic therapy for preventing GBM recurrence after radiotherapy. SIGNIFICANCE: This study uncovers mechanisms by which radiotherapy can promote GBM recurrence by inducing senescence in non-neoplastic brain cells, suggesting that senolytic therapy can blunt recurrent GBM growth and aggressiveness.
Assuntos
Encéfalo/patologia , Senescência Celular , Raios gama/efeitos adversos , Glioblastoma/patologia , Recidiva Local de Neoplasia/patologia , Fenótipo Secretor Associado à Senescência , Microambiente Tumoral , Compostos de Anilina/farmacologia , Animais , Antineoplásicos/farmacologia , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Astrócitos/patologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Glioblastoma/tratamento farmacológico , Glioblastoma/etiologia , Glioblastoma/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/etiologia , Recidiva Local de Neoplasia/metabolismo , Sulfonamidas/farmacologiaRESUMO
Itraconazole, an FDA-approved antifungal, has antitumor activity against a variety of cancers. We sought to determine the effects of itraconazole on esophageal cancer and elucidate its mechanism of action. Itraconazole inhibited cell proliferation and induced G1-phase cell-cycle arrest in esophageal squamous cell carcinoma and adenocarcinoma cell lines. Using an unbiased kinase array, we found that itraconazole downregulated protein kinase AKT phosphorylation in OE33 esophageal adenocarcinoma cells. Itraconazole also decreased phosphorylation of downstream ribosomal protein S6, transcriptional expression of the upstream receptor tyrosine kinase HER2, and phosphorylation of upstream PI3K in esophageal cancer cells. Lapatinib, a tyrosine kinase inhibitor that targets HER2, and siRNA-mediated knockdown of HER2 similarly suppressed cancer cell growth in vitro Itraconazole significantly inhibited growth of OE33-derived flank xenografts in mice with detectable levels of itraconazole and its primary metabolite, hydroxyitraconazole, in esophagi and tumors. HER2 total protein and phosphorylation of AKT and S6 proteins were decreased in xenografts from itraconazole-treated mice compared to xenografts from placebo-treated mice. In an early phase I clinical trial (NCT02749513) in patients with esophageal cancer, itraconazole decreased HER2 total protein expression and phosphorylation of AKT and S6 proteins in tumors. These data demonstrate that itraconazole has potent antitumor properties in esophageal cancer, partially through blockade of HER2/AKT signaling.
Assuntos
Neoplasias Esofágicas/tratamento farmacológico , Carcinoma de Células Escamosas do Esôfago/tratamento farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Itraconazol/farmacologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Receptor ErbB-2/antagonistas & inibidores , Animais , Apoptose , Ciclo Celular , Movimento Celular , Proliferação de Células , Inibidores do Citocromo P-450 CYP3A/farmacologia , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/metabolismo , Carcinoma de Células Escamosas do Esôfago/patologia , Feminino , Humanos , Itraconazol/farmacocinética , Dose Máxima Tolerável , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Prognóstico , Distribuição Tecidual , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Tumor necrosis factor (TNF) and its receptors are widely expressed in non-small cell lung cancer (NSCLC). TNF has an established role in inflammation and also plays a key role in inflammation-induced cancer. TNF can induce cell death in cancer cells and has been used as a treatment in certain types of cancer. However, TNF is likely to play an oncogenic role in multiple types of cancer, including NSCLC. TNF is a key activator of the transcription factor NF-κB. NF-κB, in turn, is a key effector of TNF in inflammation-induced cancer. Data from The Cancer Genome Atlas database suggest that TNF could be a biomarker in NSCLC and indicate a complex role for TNF and its receptors in NSCLC. Recent studies have reported that TNF is rapidly upregulated in NSCLC in response to targeted treatment with epidermal growth factor receptor (EGFR) inhibition, and this upregulation leads to NF-κB activation. The TNF upregulation and consequent NF-κB activation play a key role in mediating both primary and secondary resistance to EGFR inhibition in NSCLC, and a combined inhibition of EGFR and TNF can overcome therapeutic resistance in experimental models. TNF may mediate the toxic side effects of immunotherapy and may also modulate resistance to immune checkpoint inhibitors. Drugs inhibiting TNF are widely used for the treatment of various inflammatory and rheumatologic diseases and could be quite useful in combination with targeted therapy of NSCLC and other cancers.
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Suscetibilidade a Doenças , Neoplasias Pulmonares/etiologia , Neoplasias Pulmonares/metabolismo , Fatores de Necrose Tumoral/metabolismo , Animais , Biomarcadores , Biomarcadores Tumorais , Gerenciamento Clínico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , Genômica/métodos , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/terapia , Terapia de Alvo Molecular , NF-kappa B/metabolismo , Prognóstico , Resultado do Tratamento , Fatores de Necrose Tumoral/genéticaRESUMO
EGFR inhibition is an effective treatment in the minority of non-small cell lung cancer (NSCLC) cases harboring EGFR-activating mutations, but not in EGFR wild type (EGFRwt) tumors. Here, we demonstrate that EGFR inhibition triggers an antiviral defense pathway in NSCLC. Inhibiting mutant EGFR triggers Type I IFN-I upregulation via a RIG-I-TBK1-IRF3 pathway. The ubiquitin ligase TRIM32 associates with TBK1 upon EGFR inhibition, and is required for K63-linked ubiquitination and TBK1 activation. Inhibiting EGFRwt upregulates interferons via an NF-κB-dependent pathway. Inhibition of IFN signaling enhances EGFR-TKI sensitivity in EGFR mutant NSCLC and renders EGFRwt/KRAS mutant NSCLC sensitive to EGFR inhibition in xenograft and immunocompetent mouse models. Furthermore, NSCLC tumors with decreased IFN-I expression are more responsive to EGFR TKI treatment. We propose that IFN-I signaling is a major determinant of EGFR-TKI sensitivity in NSCLC and that a combination of EGFR TKI plus IFN-neutralizing antibody could be useful in most NSCLC patients.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Receptores ErbB , Neoplasias Pulmonares , Transdução de Sinais , Animais , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Proliferação de Células , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Camundongos , Inibidores de Proteínas Quinases/farmacologiaRESUMO
Mounting evidence suggests that the tumor microenvironment is profoundly immunosuppressive. Thus, mitigating tumor immunosuppression is crucial for inducing sustained antitumor immunity. Whereas previous studies involved intratumoral injection, we report here an inhalable nanoparticle-immunotherapy system targeting pulmonary antigen presenting cells (APCs) to enhance anticancer immunity against lung metastases. Inhalation of phosphatidylserine coated liposome loaded with STING agonist cyclic guanosine monophosphate-adenosine monophosphate (NP-cGAMP) in mouse models of lung metastases enables rapid distribution of NP-cGAMP to both lungs and subsequent uptake by APCs without causing immunopathology. NP-cGAMP designed for enhanced cytosolic release of cGAMP stimulates STING signaling and type I interferons production in APCs, resulting in the pro-inflammatory tumor microenvironment in multifocal lung metastases. Furthermore, fractionated radiation delivered to one tumor-bearing lung synergizes with inhaled NP-cGAMP, eliciting systemic anticancer immunity, controlling metastases in both lungs, and conferring long-term survival in mice with lung metastases and with repeated tumor challenge.
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Células Apresentadoras de Antígenos/efeitos dos fármacos , Imunoterapia , Neoplasias Pulmonares/secundário , Pulmão/efeitos dos fármacos , Melanoma Experimental/secundário , Proteínas de Membrana/agonistas , Nanopartículas , Nucleotídeos Cíclicos/farmacologia , Radioterapia , Administração por Inalação , Animais , Células Apresentadoras de Antígenos/imunologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Interferon Tipo I/efeitos dos fármacos , Interferon Tipo I/imunologia , Lipossomos , Pulmão/imunologia , Pulmão/efeitos da radiação , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Nucleotídeos Cíclicos/administração & dosagem , FosfatidilserinasRESUMO
BACKGROUND: Glioblastoma (GBM) is the most common primary malignant adult brain tumor. Temozolomide (TMZ) is the standard of care and is most effective in GBMs that lack the DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT). Moreover, even initially responsive tumors develop a secondary resistance to TMZ and become untreatable. Since aberrant epidermal growth factor receptor (EGFR) signaling is widespread in GBM, EGFR inhibition has been tried in multiple clinical trials without success. We recently reported that inhibiting EGFR leads to increased secretion of tumor necrosis factor (TNF) and activation of a survival pathway in GBM. Here, we compare the efficacy of TMZ versus EGFR plus TNF inhibition in an orthotopic mouse model of GBM. METHODS: We use an orthotopic model to examine the efficacy of TMZ versus EGFR plus TNF inhibition in multiple subsets of GBMs, including MGMT methylated and unmethylated primary GBMs, recurrent GBMs, and GBMs rendered experimentally resistant to TMZ. RESULTS: The efficacy of the 2 treatments was similar in MGMT methylated GBMs. However, in MGMT unmethylated GBMs, a combination of EGFR plus TNF inhibition was more effective. We demonstrate that the 2 treatment approaches target distinct and non-overlapping pathways. Thus, importantly, EGFR plus TNF inhibition remains effective in TMZ-resistant recurrent GBMs and in GBMs rendered experimentally resistant to TMZ. CONCLUSION: EGFR inhibition combined with a blunting of the accompanying TNF-driven adaptive response could be a viable therapeutic approach in MGMT unmethylated and recurrent EGFR-expressing GBMs.
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Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma/tratamento farmacológico , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Afatinib/administração & dosagem , Animais , Apoptose , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Proliferação de Células , Receptores ErbB/antagonistas & inibidores , Feminino , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Temozolomida/administração & dosagem , Talidomida/administração & dosagem , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Glioblastomas are lethal brain tumors that are treated with conventional radiation (X-rays and gamma rays) or particle radiation (protons and carbon ions). Paradoxically, radiation is also a risk factor for GBM development, raising the possibility that radiotherapy of brain tumors could promote tumor recurrence or trigger secondary gliomas. In this study, we determined whether tumor suppressor losses commonly displayed by patients with GBM confer susceptibility to radiation-induced glioma. Mice with Nestin-Cre-driven deletions of Trp53 and Pten alleles were intracranially irradiated with X-rays or charged particles of increasing atomic number and linear energy transfer (LET). Mice with loss of one allele each of Trp53 and Pten did not develop spontaneous gliomas, but were highly susceptible to radiation-induced gliomagenesis. Tumor development frequency after exposure to high-LET particle radiation was significantly higher compared with X-rays, in accordance with the irreparability of DNA double-strand breaks (DSB) induced by high-LET radiation. All resultant gliomas, regardless of radiation quality, presented histopathologic features of grade IV lesions and harbored populations of cancer stem-like cells with tumor-propagating properties. Furthermore, all tumors displayed concomitant loss of heterozygosity of Trp53 and Pten along with frequent amplification of the Met receptor tyrosine kinase, which conferred a stem cell phenotype to tumor cells. Our results demonstrate that radiation-induced DSBs cooperate with preexisting tumor suppressor losses to generate high-grade gliomas. Moreover, our mouse model can be used for studies on radiation-induced development of GBM and therapeutic strategies. SIGNIFICANCE: This study uncovers mechanisms by which ionizing radiation, especially particle radiation, promote GBM development or recurrence.
Assuntos
Neoplasias Encefálicas/genética , Quebras de DNA de Cadeia Dupla , Glioblastoma/genética , Glioma/genética , Neoplasias Induzidas por Radiação/genética , PTEN Fosfo-Hidrolase/genética , Proteína Supressora de Tumor p53/genética , Animais , Neoplasias Encefálicas/patologia , Feminino , Glioblastoma/patologia , Glioma/patologia , Humanos , Transferência Linear de Energia , Perda de Heterozigosidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Gradação de Tumores , Células-Tronco Neoplásicas/patologia , Células-Tronco Neoplásicas/efeitos da radiaçãoRESUMO
PURPOSE: To assess early changes in brain metastasis in response to whole brain radiotherapy (WBRT) by longitudinal Magnetic Resonance Imaging (MRI). MATERIALS AND METHODS: Using a 7T system, MRI examinations of brain metastases in a breast cancer MDA-MD231-Br mouse model were conducted before and 24 hours after 3 daily fractionations of 4 Gy WBRT. Besides anatomic MRI, diffusion-weighted (DW) MRI and dynamic contrast-enhanced (DCE) MRI were applied to study cytotoxic effect and blood-tumor-barrier (BTB) permeability change, respectively. RESULTS: Before treatment, high-resolution T2-weighted images revealed hyperintense multifocal lesions, many of which (â¼50%) were not enhanced on T1-weighted contrast images, indicating intact BTB in the brain metastases. While no difference in the number of new lesions was observed, WBRT-treated tumors were significantly smaller than sham controls (p < .05). DW MRI detected significant increase in apparent diffusion coefficient (ADC) in WBRT tumors (p < .05), which correlated with elevated caspase 3 staining of apoptotic cells. Many lesions remained non-enhanced post WBRT. However, quantitative DCE MRI analysis showed significantly higher permeability parameter, Ktrans, in WBRT than the sham group (p < .05), despite marked spatial heterogeneity. CONCLUSIONS: MRI allowed non-invasive assessments of WBRT induced changes in BTB permeability, which may provide useful information for potential combination treatment.
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Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/secundário , Neoplasias da Mama/patologia , Imageamento por Ressonância Magnética , Animais , Neoplasias Encefálicas/diagnóstico por imagem , Linhagem Celular Tumoral , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Resultado do Tratamento , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
IDH-mutant astrocytomas are significantly less aggressive than their IDH-wildtype counterparts. We analyzed The Cancer Genome Atlas dataset (TCGA) and identified a small group of IDH-mutant, WHO grade II-III astrocytomas (n = 14) with an unexpectedly poor prognosis characterized by a rapid progression to glioblastoma and death within 3 years of the initial diagnosis. Compared with IDH-mutant tumors with the typical, extended progression-free survival in a control group of age-similar patients, the tumors in the rapidly progressing group were characterized by a markedly increased level of overall copy number alterations ([CNA]; p = 0.006). In contrast, the mutation load was similar, as was the methylation pattern, being consistent with IDH-mutant astrocytoma. Two of the gliomas (14%) in the rapidly progressing, IDH-mutant group but none of the other grade II-III gliomas in the TCGA (n = 283) had pathogenic mutations in genes (FANCB and APC) associated with maintaining chromosomal stability. These results suggest that chromosomal instability can negate the beneficial effect of IDH mutations in WHO II-III astrocytomas. The mechanism of the increased CNA is unknown but in some cases appears to be due to mutations in genes with a role in chromosomal stability. Increased CNA could serve as a biomarker for tumors at risk for rapid progression.
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Astrocitoma/genética , Astrocitoma/patologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Epigênese Genética/genética , Isocitrato Desidrogenase/genética , Adulto , Biomarcadores , Metilação de DNA/genética , Progressão da Doença , Feminino , Dosagem de Genes , Glioblastoma/patologia , Humanos , Masculino , Mutação/genética , Prognóstico , Análise de Sobrevida , Resultado do TratamentoRESUMO
Although aberrant EGFR signaling is widespread in cancer, EGFR inhibition is effective only in a subset of non-small cell lung cancer (NSCLC) with EGFR activating mutations. A majority of NSCLCs express EGFR wild type (EGFRwt) and do not respond to EGFR inhibition. TNF is a major mediator of inflammation-induced cancer. We find that a rapid increase in TNF level is a universal adaptive response to EGFR inhibition in NSCLC, regardless of EGFR status. EGFR signaling actively suppresses TNF mRNA levels by inducing expression of miR-21, resulting in decreased TNF mRNA stability. Conversely, EGFR inhibition results in loss of miR-21 and increased TNF mRNA stability. In addition, TNF-induced NF-κB activation leads to increased TNF transcription in a feed-forward loop. Inhibition of TNF signaling renders EGFRwt-expressing NSCLC cell lines and an EGFRwt patient-derived xenograft (PDX) model highly sensitive to EGFR inhibition. In EGFR-mutant oncogene-addicted cells, blocking TNF enhances the effectiveness of EGFR inhibition. EGFR plus TNF inhibition is also effective in NSCLC with acquired resistance to EGFR inhibition. We suggest concomitant EGFR and TNF inhibition as a potentially new treatment approach that could be beneficial for a majority of lung cancer patients.
Assuntos
Resistencia a Medicamentos Antineoplásicos , Neoplasias Pulmonares/metabolismo , Proteínas de Neoplasias , Neoplasias Experimentais/metabolismo , Fator de Necrose Tumoral alfa , Células A549 , Animais , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/terapia , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Receptores ErbB/metabolismo , Feminino , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/terapia , Camundongos , Camundongos Nus , MicroRNAs/genética , MicroRNAs/metabolismo , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neoplasias Experimentais/genética , Neoplasias Experimentais/patologia , Neoplasias Experimentais/terapia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Neoplásico/genética , RNA Neoplásico/metabolismo , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The interleukin-13 receptor alpha2 (IL-13Rα2) is a cancer-associated receptor overexpressed in human glioblastoma multiforme (GBM). This receptor is undetectable in normal brain which makes it a highly suitable target for diagnostic and therapeutic purposes. However, the pathological role of this receptor in GBM remains to be established. Here we report that IL-13Rα2 alone induces invasiveness of human GBM cells without affecting their proliferation. In contrast, in the presence of the mutant EGFR (EGFRvIII), IL-13Rα2 promotes GBM cell proliferation in vitro and in vivo. Mechanistically, the cytoplasmic domain of IL-13Rα2 specifically binds to EGFRvIII, and this binding upregulates the tyrosine kinase activity of EGFRvIII and activates the RAS/RAF/MEK/ERK and STAT3 pathways. Our findings support the "To Go or To Grow" hypothesis whereby IL-13Rα2 serves as a molecular switch from invasion to proliferation, and suggest that targeting both receptors with STAT3 signaling inhibitor might be a therapeutic approach for the treatment of GBM.
Assuntos
Neoplasias Encefálicas/genética , Proliferação de Células/genética , Receptores ErbB/genética , Glioblastoma/genética , Subunidade alfa2 de Receptor de Interleucina-13/genética , Animais , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Técnicas de Silenciamento de Genes , Glioblastoma/metabolismo , Glioblastoma/mortalidade , Glioblastoma/patologia , Humanos , Técnicas In Vitro , Subunidade alfa2 de Receptor de Interleucina-13/metabolismo , MAP Quinase Quinase Quinases/metabolismo , Camundongos , Mutação , Invasividade Neoplásica/genética , Transplante de Neoplasias , RNA Mensageiro/metabolismo , Taxa de Sobrevida , Quinases raf/metabolismo , Proteínas ras/metabolismoRESUMO
Epidermal growth factor receptor (EGFR) plays an important role in various types of human cancers. Overexpression of EGFR leads to a constitutive tyrosine phosphorylation of multiple tyrosine residues in the EGFR. Recently, we have demonstrated that overexpressed EGFR oscillates between two distinct and mutually exclusive modes of signaling depending on the presence or absence of ligand. EGFR constitutively activates transcription factor IRF3, which results in transcription of its target genes. Addition of EGF causes a loss of IRF3 transcriptional activity and activation of canonical signaling pathways such as ERK. The mechanistic basis of this bimodal signaling appears to be the association of a distinct set of signaling proteins with EGFR in the absence or presence of ligand. In this chapter, we describe a detailed protocol for analyses of constitutive EGFR signaling with a focus on IRF3 target genes.
Assuntos
Receptores ErbB/metabolismo , Regulação Neoplásica da Expressão Gênica , Fator Regulador 3 de Interferon/metabolismo , Neoplasias/genética , Neoplasias/metabolismo , Transdução de Sinais , Sítios de Ligação , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Ligação ProteicaRESUMO
Phosphatidylserine (PS), the most abundant anionic phospholipid in cell membrane, is strictly confined to the inner leaflet in normal cells. However, this PS asymmetry is found disruptive in many tumor vascular endothelial cells. We discuss the underlying mechanisms for PS asymmetry maintenance in normal cells and its loss in tumor cells. The specificity of PS exposure in tumor vasculature but not normal blood vessels may establish it a useful biomarker for cancer molecular imaging. Indeed, utilizing PS-targeting antibodies, multiple imaging probes have been developed and multimodal imaging data have shown their high tumor-selective targeting in various cancers. There is a critical need for improved diagnosis and therapy for brain tumors. We have recently established PS-targeted nanoplatforms, aiming to enhance delivery of imaging contrast agents across the blood-brain barrier to facilitate imaging of brain tumors. Advantages of using the nanodelivery system, in particular, lipid-based nanocarriers, are discussed here. We also describe our recent research interest in developing PS-targeted nanotheranostics for potential image-guided drug delivery to treat brain tumors.
Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Imagem Molecular/métodos , Fosfatidilserinas/análise , Animais , Barreira Hematoencefálica/diagnóstico por imagem , Linhagem Celular Tumoral , HumanosRESUMO
Aberrant epidermal growth factor receptor (EGFR) signaling is widespread in cancer, making the EGFR an important target for therapy. EGFR gene amplification and mutation are common in glioblastoma (GBM), but EGFR inhibition has not been effective in treating this tumor. Here we propose that primary resistance to EGFR inhibition in glioma cells results from a rapid compensatory response to EGFR inhibition that mediates cell survival. We show that in glioma cells expressing either EGFR wild type or the mutant EGFRvIII, EGFR inhibition triggers a rapid adaptive response driven by increased tumor necrosis factor (TNF) secretion, which leads to activation in turn of c-Jun N-terminal kinase (JNK), the Axl receptor tyrosine kinase and extracellular signal-regulated kinases (ERK). Inhibition of this adaptive axis at multiple nodes rendered glioma cells with primary resistance sensitive to EGFR inhibition. Our findings provide a possible explanation for the failures of anti-EGFR therapy in GBM and suggest a new approach to the treatment of EGFR-expressing GBM using a combination of EGFR and TNF inhibition.