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1.
Anticancer Res ; 40(10): 5379-5391, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32988857

RESUMO

BACKGROUND/AIM: Hypoxia-inducible factor 1 (HIF1) inhibitors have been proposed as therapeutic agents for several tumor types. HIF1α is induced by hypoxia and by pathogens in normoxia through toll-like receptors (TLRs). The TLR3 activator polyinosinic:polycytidylic acid [poly(I:C)] induces apoptosis in various types of cancer but not in the most aggressive breast cancer cell lines. We hypothesized that the failure of TLR3 stimulation to induce apoptosis in these cells might be due to an elevated HIF1α level and this link might be exploited. MATERIALS AND METHODS: Poly(I:C)-induced signaling pathway and expression of HIF1α and HIF1α targets were studied in MDA MB-231 and MCF-7 breast cancer cell lines by western blot. Flow cytometry was used for apoptotic responses and vasculogenic mimicry as bioassay. RESULTS: Poly(I:C) increased expression of HIF1α and its targets BCL2 apoptosis regulator and c-MYC. Moreover, using pharmacological or genetic HIF1 inhibition, reduction of poly(I:C)-induced expression of HIF1α was paralleled by lowering of c-MYC and increased sensitivity to poly(I:C)-induced apoptosis, demonstrating the crucial role of this factor. We provide the first evidence in breast cancer cells that TLR3 stimulation induces HIF1α-dependent vasculogenic mimicry. By using specific inhibitors, we identified a signaling cascade upstream of HIF1α induction. CONCLUSION: Combined treatment with poly(I:C) and HIF1 inhibitors deserves consideration as an effective strategy in breast cancer therapy.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Poli I-C/farmacologia , Receptor 3 Toll-Like/genética , Apoptose/efeitos dos fármacos , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Proliferação de Células/efeitos dos fármacos , Feminino , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Células MCF-7 , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-myc/genética , Transdução de Sinais/efeitos dos fármacos , Receptor 3 Toll-Like/agonistas
2.
Tumour Biol ; 42(9): 1010428320954735, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32873193

RESUMO

Acute myeloid leukemia is the most common form of acute leukemia in adults, constituting about 80% of cases. Although remarkable progress has been made in the therapeutic scenario for patients with acute myeloid leukemia, research and development of new and effective anticancer agents to improve patient outcome and minimize toxicity is needed. In this study, the antitumor activity of axolotl (AXO) Ambystoma mexicanum crude extract was assessed in vitro on the human acute myeloid leukemia HL-60 cell line. The anticancer activity was evaluated in terms of ability to influence proliferative activity, cell viability, cell cycle arrest, and differentiation. Moreover, gene expression analysis was performed to evaluate the genes involved in the regulation of these processes. The AXO crude extract exhibited antiproliferative but not cytotoxic activities on HL-60 cells, with cell cycle arrest in the G0/G1 phase. Furthermore, the AXO-treated HL-60 cells showed an increase in both the percentage of nitroblue tetrazolium positive cells and the expression of CD11b, whereas the proportion of CD14-positive cells did not change, suggesting that extract is able to induce differentiation toward the granulocytic lineage. Finally, the treatment with AXO extract caused upregulation of CEBPA, CEBPB, CEBPE, SPI1, CDKN1A, and CDKN2C, and downregulation of c-MYC. Our data clearly show the potential anticancer activity of Ambystoma mexicanum on HL-60 cells and suggest that it could help develop promising therapeutic agents for the treatment of acute myeloid leukemia.


Assuntos
Ambystoma mexicanum , Proliferação de Células/efeitos dos fármacos , Misturas Complexas/farmacologia , Leucemia Mieloide Aguda/tratamento farmacológico , Animais , Proteína beta Intensificadora de Ligação a CCAAT/genética , Proteínas Estimuladoras de Ligação a CCAAT/genética , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p18/genética , Inibidor de Quinase Dependente de Ciclina p21/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HL-60 , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Proteínas Proto-Oncogênicas c-myc/genética
3.
Nat Commun ; 11(1): 4153, 2020 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-32814769

RESUMO

The histone methyltransferase DOT1L methylates lysine 79 (K79) on histone H3 and is involved in Mixed Lineage Leukemia (MLL) fusion leukemogenesis; however, its role in prostate cancer (PCa) is undefined. Here we show that DOT1L is overexpressed in PCa and is associated with poor outcome. Genetic and chemical inhibition of DOT1L selectively impaired the viability of androgen receptor (AR)-positive PCa cells and organoids, including castration-resistant and enzalutamide-resistant cells. The sensitivity of AR-positive cells is due to a distal K79 methylation-marked enhancer in the MYC gene bound by AR and DOT1L not present in AR-negative cells. DOT1L inhibition leads to reduced MYC expression and upregulation of MYC-regulated E3 ubiquitin ligases HECTD4 and MYCBP2, which promote AR and MYC degradation. This leads to further repression of MYC in a negative feed forward manner. Thus DOT1L selectively regulates the tumorigenicity of AR-positive prostate cancer cells and is a promising therapeutic target for PCa.


Assuntos
Histona-Lisina N-Metiltransferase/genética , Neoplasias da Próstata/genética , Proteínas Proto-Oncogênicas c-myc/genética , Receptores Androgênicos/genética , Adenosina/análogos & derivados , Adenosina/farmacologia , Animais , Linhagem Celular Tumoral , Intervalo Livre de Doença , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Histona-Lisina N-Metiltransferase/antagonistas & inibidores , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Masculino , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Compostos de Fenilureia/farmacologia , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/terapia , Estabilidade Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-myc/metabolismo , Interferência de RNA , Terapêutica com RNAi/métodos , Receptores Androgênicos/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
4.
Ann Hematol ; 99(10): 2377-2384, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32728938

RESUMO

This study investigated the prognostic value of 25-hydroxy vitamin D (25-(OH)D) deficiency and the association between 25-(OH)D deficiency and c-Myc positivity in 208 newly diagnosed diffuse large B cell lymphoma (DLBCL) patients. 25-(OH)D deficiency was defined as serum 25-(OH)D level lower than 52.5 nmol/L. Using cutoff values of 40%, positive tumor cells for c-Myc expression was established. One hundred forty-two patients had 25-(OH)D deficiency and 70 had c-Myc positivity with a median follow-up of 29 months (range, 16 to 49 months) in this cohort. Multivariate Cox regression analysis showed that 25-(OH)D deficiency was an independent prognostic predictor for inferior progression-free survival (PFS) (P = 0.001) and overall survival (OS) (P = 0.006), and c-Myc positivity was an unfavorable prognostic factor for PFS (P = 0.004). In addition, c-Myc positivity was more frequent in patients with 25-(OH)D deficiency (P = 0.027). Moreover, we found that the presence of c-Myc positivity could aggravate the adverse effects of 25-(OH)D deficiency for PFS time (P = 0.0045). 25-(OH)D deficiency together with IPI (IPI-D) improved the prognostic capacity compared with only IPI in predicting the risk of DLBCL which was assessed by the calculation of receiver operator characteristic (ROC) curves and the areas under the curve (AUC). Noteworthy, c-Myc positivity combined with IPI-D was better than IPI-D in predicting PFS time. In summary, 25-(OH)D deficiency was a strong prognostic factor in DLBCL. Further multi-center prospective studies are needed to confirm the results and better understand the underlying mechanisms.


Assuntos
Genes myc , Linfoma Difuso de Grandes Células B/epidemiologia , Proteínas de Neoplasias/biossíntese , Proteínas Proto-Oncogênicas c-myc/biossíntese , Deficiência de Vitamina D/epidemiologia , Vitamina D/análogos & derivados , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Área Sob a Curva , China/epidemiologia , Comorbidade , Ciclofosfamida/administração & dosagem , Progressão da Doença , Doxorrubicina/administração & dosagem , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Linfoma Difuso de Grandes Células B/sangue , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/genética , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Prednisona/administração & dosagem , Modelos de Riscos Proporcionais , Proteínas Proto-Oncogênicas c-myc/genética , Curva ROC , Vincristina/administração & dosagem , Vitamina D/sangue , Deficiência de Vitamina D/sangue , Adulto Jovem
5.
Brain Tumor Pathol ; 37(4): 127-135, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32627089

RESUMO

In recent years, the features of lymphomas associated with chronic inflammation, referred to as diffuse large B-cell lymphoma (DLBCL) associated with chronic inflammation (DLBCL-CI), have been elucidated. DLBCL-CI is an aggressive lymphoma occurring in the context of long-standing chronic inflammation and showing an association with Epstein-Barr virus. Fibrin-associated diffuse large B-cell lymphoma (F-DLBCL) was suggested as a new and unusual form of DLBCL-CI in the most recent version of the World Health Organization classification. From the perspective of genetics, DLBCL-CI was associated with frequent TP53 mutation, MYC amplification and complex karyotypes, but cases of F-DLBCL behaved indolently and showed a relatively lower genetic complexity. In the central nervous system (CNS), several examples of DLBCL-CI and F-DLBCL have been reported. As with DLBCL-CI outside the CNS, DLBCL-CI in the CNS is an aggressive lymphoma. However, the clinical outcome of F-DLBCL in the CNS is good. Immunohistochemistry for p53 and c-Myc in DLBCL-CI and F-DLBCL in the CNS showed similar findings of those outside the CNS. However, one aggressive case showed transitional genetics and morphology between F-DLBCL and DLBCL-CI. These findings suggest that some cases of F-DLBCL in the CNS might have the potential to progress to DLBCL-CI.


Assuntos
Neoplasias do Sistema Nervoso Central/diagnóstico , Linfoma Difuso de Grandes Células B/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Neoplasias do Sistema Nervoso Central/diagnóstico por imagem , Neoplasias do Sistema Nervoso Central/genética , Neoplasias do Sistema Nervoso Central/patologia , Progressão da Doença , Fibrina , Humanos , Inflamação , Linfoma Difuso de Grandes Células B/diagnóstico por imagem , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/patologia , Mutação , Proteínas Proto-Oncogênicas c-myc/genética , Proteína Supressora de Tumor p53/genética
6.
Nat Commun ; 11(1): 2860, 2020 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-32503978

RESUMO

The MYC oncogene drives T- and B- lymphoid malignancies, including Burkitt's lymphoma (BL) and Acute Lymphoblastic Leukemia (ALL). Here, we demonstrate a systemic reduction in natural killer (NK) cell numbers in SRα-tTA/Tet-O-MYCON mice bearing MYC-driven T-lymphomas. Residual mNK cells in spleens of MYCON T-lymphoma-bearing mice exhibit perturbations in the terminal NK effector differentiation pathway. Lymphoma-intrinsic MYC arrests NK maturation by transcriptionally repressing STAT1/2 and secretion of Type I Interferons (IFNs). Treating T-lymphoma-bearing mice with Type I IFN improves survival by rescuing NK cell maturation. Adoptive transfer of mature NK cells is sufficient to delay both T-lymphoma growth and recurrence post MYC inactivation. In MYC-driven BL patients, low expression of both STAT1 and STAT2 correlates significantly with the absence of activated NK cells and predicts unfavorable clinical outcomes. Our studies thus provide a rationale for developing NK cell-based therapies to effectively treat MYC-driven lymphomas in the future.


Assuntos
Linfoma de Burkitt/imunologia , Células Matadoras Naturais/imunologia , Linfoma de Células T/imunologia , Proteínas Proto-Oncogênicas c-myc/metabolismo , Transferência Adotiva , Animais , Linfoma de Burkitt/mortalidade , Linhagem Celular Tumoral/transplante , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica/imunologia , Humanos , Vigilância Imunológica/genética , Interferon Tipo I/farmacologia , Interferon Tipo I/uso terapêutico , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/transplante , Linfoma de Células T/tratamento farmacológico , Linfoma de Células T/genética , Linfoma de Células T/patologia , Masculino , Camundongos , Cultura Primária de Células , Proteínas Proto-Oncogênicas c-myc/genética , Fator de Transcrição STAT1/metabolismo , Fator de Transcrição STAT2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transdução de Sinais/imunologia
7.
PLoS One ; 15(6): e0232068, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32559187

RESUMO

Cyclin Dependent Kinase 9 (CDK9) associates with Bromodomain and Extra-Terminal Domain (BET) proteins to promote transcriptional elongation by phosphorylation of serine 2 of RNAP II C-terminal domain. We examined the therapeutic potential of selective CDK9 inhibitors (AZD 4573 and MC180295) against human multiple myeloma cells in vitro. Short-hairpin RNA silencing of CDK9 in Multiple Myeloma (MM) cell lines reduced cell viability compared to control cells showing the dependency of MM cells on CDK9. In order to explore synergy with the CDK9 inhibitor, proteolysis targeting chimeric molecule (PROTAC) ARV 825 was added. This latter drug causes ubiquitination of BET proteins resulting in their rapid and efficient degradation. Combination treatment of MM cells with ARV 825 and AZD 4573 markedly reduced their protein expression of BRD 2, BRD 4, MYC and phosphorylated RNA pol II as compared to each single agent alone. Combination treatment synergistically inhibited multiple myeloma cells both in vitro and in vivo with insignificant weight loss. The combination also resulted in marked increase of apoptotic cells at low dose compared to single agent alone. Taken together, our studies show for the first time that the combination of a BET PROTAC (ARV 825) plus AZD 4573 (CDK9 inhibitor) is effective against MM cells.


Assuntos
Quinase 9 Dependente de Ciclina/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Proteínas/metabolismo , Proteólise/efeitos dos fármacos , Animais , Azepinas/farmacologia , Azepinas/uso terapêutico , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Quinase 9 Dependente de Ciclina/genética , Quinase 9 Dependente de Ciclina/metabolismo , Regulação para Baixo/efeitos dos fármacos , Sinergismo Farmacológico , Humanos , Camundongos , Camundongos SCID , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/patologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas/genética , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Interferência de RNA , RNA Polimerase II/metabolismo , RNA Interferente Pequeno/metabolismo , Talidomida/análogos & derivados , Talidomida/farmacologia , Talidomida/uso terapêutico , Transplante Heterólogo
8.
Nucleic Acids Res ; 48(13): 7439-7453, 2020 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-32501500

RESUMO

Despite two decades of study, the full scope of RNAi in mammalian cells has remained obscure. Here we combine: (i) Knockout of argonaute (AGO) variants; (ii) RNA sequencing analysis of gene expression changes and (iii) Enhanced Crosslinking Immunoprecipitation Sequencing (eCLIP-seq) using anti-AGO2 antibody to identify potential microRNA (miRNA) binding sites. We find that knocking out AGO1, AGO2 and AGO3 together are necessary to achieve full impact on steady state levels of mRNA. eCLIP-seq located AGO2 protein associations within 3'-untranslated regions. The standard mechanism of miRNA action would suggest that these associations should repress gene expression. Contrary to this expectation, associations between AGO and RNA are poorly correlated with gene repression in wild-type versus knockout cells. Many clusters are associated with increased steady state levels of mRNA in wild-type versus knock out cells, including the strongest cluster within the MYC 3'-UTR. Our results suggest that assumptions about miRNA action should be re-examined.


Assuntos
Regiões 3' não Traduzidas , Proteínas Argonauta/metabolismo , Inativação Gênica , Proteínas Argonauta/química , Proteínas Argonauta/genética , Sítios de Ligação , Células HCT116 , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Ligação Proteica , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo
9.
Proc Natl Acad Sci U S A ; 117(24): 13457-13467, 2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32482868

RESUMO

The protooncogene MYC regulates a variety of cellular processes, including proliferation and metabolism. Maintaining MYC at homeostatic levels is critical to normal cell function; overexpression drives many cancers. MYC stability is regulated through phosphorylation: phosphorylation at Thr58 signals degradation while Ser62 phosphorylation leads to its stabilization and functional activation. The bromodomain protein 4 (BRD4) is a transcriptional and epigenetic regulator with intrinsic kinase and histone acetyltransferase (HAT) activities that activates transcription of key protooncogenes, including MYC We report that BRD4 phosphorylates MYC at Thr58, leading to MYC ubiquitination and degradation, thereby regulating MYC target genes. Importantly, BRD4 degradation, but not inhibition, results in increased levels of MYC protein. Conversely, MYC inhibits BRD4's HAT activity, suggesting that MYC regulates its own transcription by limiting BRD4-mediated chromatin remodeling of its locus. The MYC stabilizing kinase, ERK1, regulates MYC levels directly and indirectly by inhibiting BRD4 kinase activity. These findings demonstrate that BRD4 negatively regulates MYC levels, which is counteracted by ERK1 activation.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Fatores de Transcrição/metabolismo , Acetilação , Núcleo Celular/metabolismo , Cromatina/metabolismo , Dipeptídeos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Células HeLa , Compostos Heterocíclicos com 3 Anéis/farmacologia , Histonas/metabolismo , Humanos , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fosforilação , Ligação Proteica , Estabilidade Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-myc/genética , Ubiquitinação
10.
Life Sci ; 253: 117736, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32360571

RESUMO

AIMS: Recently, studies indicated that inflammation could exacerbate the development of BC. Karyopherin α-2 (KPNA2) is a molecule which modulates nucleocytoplasmic transport and is involved in malignant cellular behavior and carcinogenesis. Our study aims to elucidate the role of KPNA2 in BC pathogenesis and explore the mechanism of KPNA2 in regulating inflammation-induced BC exacerbations. MAIN METHODS: We measured the expression of KPNA2 in BC cells. Through loss-of-function experiments, the functional role of KPNA2 in MCF-7 and MDA-MB-468 cells was evaluated. SK-BR-3 cells were treated with IL-6 as an inflammatory in vitro model of BC. ELISA determination exhibited the contents of cytokines. RANKL and leptomycin B treatments activated NF-κB signaling and inhibited the nuclear translocation of c-Myc, respectively. KEY FINDINGS: The results showed that KPNA2 was significantly up-regulated in BC and silencing KPNA2 inhibited the proliferation, migration and invasion of BC cells, while the cycle arrest was induced, via blocking NF-κB signaling and c-Myc nuclear translocation. IL-6 stimulated the secretions of IL-8 and IL-17 in BC cells, and elevated KPNA2 expression. However, KPNA2 knockdown suppressed the inflammatory responses and malignant progression of BC induced by IL-6. SIGNIFICANCE: In conclusion, our study illustrated that KPNA2 regulated BC development, as well as IL-6-induced inflammation and exacerbation, via NF-κB signaling and c-Myc nuclear translocation. This may provide a novel target for BC therapy.


Assuntos
Neoplasias da Mama/patologia , Inflamação/patologia , Interleucina-6/metabolismo , alfa Carioferinas/genética , Neoplasias da Mama/genética , Linhagem Celular , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Proliferação de Células/genética , Feminino , Técnicas de Silenciamento de Genes , Inativação Gênica , Humanos , Células MCF-7 , NF-kappa B/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Transdução de Sinais , Regulação para Cima
11.
Cancer Sci ; 111(7): 2336-2348, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32437590

RESUMO

Dietary fat consumption during accelerated stages of mammary gland development, such as peripubertal maturation or pregnancy, is known to increase the risk for breast cancer. However, the underlying molecular mechanisms are not fully understood. Here we examined the gene expression profile of mouse mammary epithelial cells (MMECs) on exposure to a high-fat diet (HFD) or control diet (CD). Trp53-/- female mice were fed with the experimental diets for 5 weeks during the peripubertal period (3-8 weeks of age). The treatment showed no significant difference in body weight between the HFD-fed mice and CD-fed mice. However, gene set enrichment analysis predicted a significant enrichment of c-Myc target genes in animals fed HFD. Furthermore, we detected enhanced activity and stabilization of c-Myc protein in MMECs exposed to a HFD. This was accompanied by augmented c-Myc phosphorylation at S62 with a concomitant increase in ERK phosphorylation. Moreover, MMECs derived from HFD-fed Trp53-/- mouse showed increased colony- and sphere-forming potential that was dependent on c-Myc. Further, oleic acid, a major fatty acid constituent of the HFD, and TAK-875, an agonist to G protein-coupled receptor 40 (a receptor for oleic acid), enhanced c-Myc stabilization and MMEC proliferation. Overall, our data indicate that HFD influences MMECs by stabilizing an oncoprotein, pointing to a novel mechanism underlying dietary fat-mediated mammary carcinogenesis.


Assuntos
Dieta Hiperlipídica , Epitélio/metabolismo , Glândulas Mamárias Animais/metabolismo , Glândulas Mamárias Animais/patologia , Proteínas Proto-Oncogênicas c-myc/metabolismo , Maturidade Sexual , Animais , Linhagem Celular Tumoral , Feminino , Genes p53 , Humanos , Camundongos , Camundongos Knockout , Obesidade/etiologia , Obesidade/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Puberdade , Células Tumorais Cultivadas
12.
Toxicol Appl Pharmacol ; 399: 115056, 2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32445756

RESUMO

The c-MYC is one of the most commonly discussed oncogenes in almost all cancers. c-MYC, as a proto-oncogene in normal cells, has found to be tightly controlled and regulated, both genetically and epigenetically. Evasion of the controlled checkpoint mechanisms during cancer causes a deregulated expression of c-MYC. Overexpression of c-MYC causes the onset of many hallmarks of cancer. Despite c-MYC being centrally located in several cancers, it is not feasible to target c-MYC in therapeutic resistant cancers. Similarly, long non-coding RNAs (lncRNAs) are deregulated during the genesis and progression of different cancers. LncRNAs contribute to almost 27% human genome and recent findings by tumor genome sequencing revealed many of the lncRNAs loci that are modified, deleted, amplified, and mutated during the different stages of cancer development. Recent studies also reported that multiple lncRNAs regulate c-MYC by different mechanisms and vice versa. Thus, oncogenic lncRNAs and c-MYC interaction are positioned to provide an interesting choice for therapeutic interventions in cancers. In this mini-review, we summarize the recent discoveries and explain how the interaction between oncogenic lncRNAs and c-MYC could be used as a possible target for therapeutic intervention in cancers, especially the therapeutic resistant metastatic cancers.


Assuntos
Metástase Neoplásica/genética , Neoplasias/genética , Proteínas Proto-Oncogênicas c-myc/genética , RNA Longo não Codificante/genética , Animais , Carcinogênese/genética , Carcinogênese/patologia , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Metástase Neoplásica/patologia , Neoplasias/patologia
13.
Ann Hematol ; 99(9): 2149-2157, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32390113

RESUMO

Although MYC and BCL2 co-expression in diffuse large B cell lymphoma (DLBCL) is associated with inferior prognosis, it remains uncertain whether upfront autologous hematopoietic stem cell transplantation (ASCT) is beneficial in this lymphoma. This study aimed to investigate whether ASCT consolidation could have a positive role for patients with MYC and BCL2 co-expression (double-expressor lymphoma, DEL). We retrospectively evaluated 67 DLBCL patients who underwent upfront ASCT following rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy. The 5-year overall survival (OS) and progression-free survival (PFS) were 82.3% and 79.2%, respectively. There were 23 (34.3%) patients with DEL and 51 (76.1%) patients with non-germinal center B cell (GCB) subtype. The 5-year OS and PFS of patients with DEL were not different from those with non-DEL (P = 0.429 and P = 0.614, respectively). No survival difference for OS and PFS was also observed between GCB and non-GCB subtypes (P = 0.950 and P = 0.901, respectively). The OS and PFS were comparable for patients with DEL and non-DEL and both GCB and non-GCB subtypes. In conclusion, MYC and BCL2 co-expression did not have a poor prognostic impact among high-risk patients with DLBCL treated with upfront ASCT regardless of molecular classification. This preliminary study suggested that the role of consolidative ASCT is needed to be evaluated in a prospective randomized clinical trial.


Assuntos
Regulação Neoplásica da Expressão Gênica , Transplante de Células-Tronco Hematopoéticas/métodos , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/terapia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-myc/genética , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ciclofosfamida/uso terapêutico , Doxorrubicina/uso terapêutico , Feminino , Humanos , Linfoma Difuso de Grandes Células B/diagnóstico , Masculino , Pessoa de Meia-Idade , Prednisona/uso terapêutico , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Proteínas Proto-Oncogênicas c-myc/biossíntese , Estudos Retrospectivos , Fatores de Risco , Transplante Autólogo/métodos , Vincristina/uso terapêutico , Adulto Jovem
14.
Nat Commun ; 11(1): 2666, 2020 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-32471990

RESUMO

Multiple myeloma is a plasma cell blood cancer with frequent chromosomal translocations leading to gene fusions. To determine the clinical relevance of fusion events, we detect gene fusions from a cohort of 742 patients from the Multiple Myeloma Research Foundation CoMMpass Study. Patients with multiple clinic visits enable us to track tumor and fusion evolution, and cases with matching peripheral blood and bone marrow samples allow us to evaluate the concordance of fusion calls in patients with high tumor burden. We examine the joint upregulation of WHSC1 and FGFR3 in samples with t(4;14)-related fusions, and we illustrate a method for detecting fusions from single cell RNA-seq. We report fusions at MYC and a neighboring gene, PVT1, which are related to MYC translocations and associated with divergent progression-free survival patterns. Finally, we find that 4% of patients may be eligible for targeted fusion therapies, including three with an NTRK1 fusion.


Assuntos
Fusão Gênica/genética , Histona-Lisina N-Metiltransferase/genética , Mieloma Múltiplo/genética , Proteínas Proto-Oncogênicas c-myc/genética , Receptor Tipo 3 de Fator de Crescimento de Fibroblastos/genética , Proteínas Repressoras/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Variações do Número de Cópias de DNA/genética , Perfilação da Expressão Gênica/métodos , Histona-Lisina N-Metiltransferase/biossíntese , Humanos , Imunoglobulinas/genética , Pessoa de Meia-Idade , Intervalo Livre de Progressão , RNA Longo não Codificante/genética , RNA-Seq/métodos , Receptor Tipo 3 de Fator de Crescimento de Fibroblastos/biossíntese , Receptor trkA/genética , Proteínas Repressoras/biossíntese
15.
J Cancer Res Ther ; 16(1): 183-185, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32362635

RESUMO

Diffuse large B-cell lymphomas (DLBCL) with MYC translocations combined with translocations involving BCL-2 or BCL-6 are referred to as double-hit lymphomas. These lymphomas are generally refractory to currently available therapies and have a poor prognosis. Primary mediastinal B-cell lymphoma (PMBL) is a rare subtype of DLBCL, which shares clinical, pathologic, and genetic similarities with classical Hodgkin's lymphoma. Unlike DLBCL, rearrangements involving MYC, BCL-2, and BCL-6 are typically absent in PMBL. We present a patient with PMBL who had increased gene copy numbers of MYC and BCL-2 along with increased protein expression of BCL-2 (c-Myc expression was about 15%-20% by immunostain). The disease was refractory to standard and salvage chemotherapies. The lymphoma, however, responded to brentuximab vedotin, a CD30-directed chemoimmunoconjugate.


Assuntos
Brentuximab Vedotin/uso terapêutico , Antígeno Ki-1/metabolismo , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Neoplasias do Mediastino/tratamento farmacológico , Mutação , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Adulto , Antineoplásicos Imunológicos/uso terapêutico , Feminino , Humanos , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma Difuso de Grandes Células B/patologia , Neoplasias do Mediastino/genética , Neoplasias do Mediastino/metabolismo , Neoplasias do Mediastino/patologia , Prognóstico , Proteínas Proto-Oncogênicas c-bcl-2/genética
16.
PLoS One ; 15(4): e0231419, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32282835

RESUMO

Barrett's esophagus is the only known mucosal precursor for the highly malignant esophageal adenocarcinoma. Malignant degeneration of non-dysplastic Barrett's esophagus occurs in < 0.6% per year in Dutch surveillance cohorts. Therefore, it has been proposed to increase the surveillance intervals from 3 to 5 years, potentially increasing development of advanced stage interval cancers. To prevent such cases robust biomarkers for more optimal stratification over longer follow up periods for non-dysplastic Barrett's patients are required. In this multi-center study, aberrations for chromosomes 7, 17, and structural abnormalities for c-MYC, CDKN2A, TP53, Her-2/neu and 20q assessed by DNA fluorescence in situ hybridization on brush cytology specimens, were used to determine marker scores and to perform clonal diversity measurements, as described previously. In this study, these genetic biomarkers were combined with clinical variables and analyzed to obtain the most efficient cancer prediction model after an extended period of follow-up (median time of 7 years) by applying Cox regression modeling, bootstrapping and leave-one-out analyses. A total of 334 patients with Barrett's esophagus without dysplasia from 6 community hospitals (n = 220) and one academic center (n = 114) were included. The annual progression rate to high grade dysplasia and/or esophageal adenocarcinoma was 1.3%, and to adenocarcinoma alone 0.85%. A prediction model including age, Barrett circumferential length, and a clonicity score over the genomic set including chromosomes 7, 17, 20q and c-MYC, resulted in an area under the curve of 0.88. The sensitivity and specificity of this model were 0.91 and 0.38. The positive and negative predictive values were 0.13 (95% CI 0.09 to 0.19) and 0.97 (95% CI 0.93 to 0.99). We propose the implementation of the model to identify non-dysplastic Barrett's patients, who are required to remain in surveillance programs with 3-yearly surveillance intervals from those that can benefit from less frequent or no surveillance.


Assuntos
Esôfago de Barrett/diagnóstico , Biomarcadores/metabolismo , Adulto , Idoso , Área Sob a Curva , Esôfago de Barrett/genética , Esôfago de Barrett/patologia , Cromossomos Humanos Par 17/genética , Cromossomos Humanos Par 7/genética , Progressão da Doença , Neoplasias Esofágicas/diagnóstico , Feminino , Seguimentos , Humanos , Hiperplasia , Masculino , Pessoa de Meia-Idade , Países Baixos , Modelos de Riscos Proporcionais , Proteínas Proto-Oncogênicas c-myc/genética , Curva ROC , Fatores de Risco
17.
Jpn J Clin Oncol ; 50(4): 446-455, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32297641

RESUMO

OBJECTIVE: The purpose of this study was to explore the prognostic role of c-MYC amplification in colorectal cancer, particularly in schistosomiasis-associated colorectal cancer. METHODS: Three hundred and fifty four cases of colorectal cancer, which were from Qingpu Branch of Zhongshan Hospital affiliated to Fudan University, were retrospectively analyzed in a tissue microarray (TMA) format, with fluorescence in situ hybridization (FISH) assay and immunohistochemistry (IHC). RESULTS: c-MYC gene amplification was found in 14.1% (50 out of 354) of patients with colorectal cancer and was correlated with old age (P = 0.028), positive lymph node metastasis (P = 0.004) and advanced stage tumors (P = 0.002). The overexpression of c-MYC was closely associated with the amplification status (P = 0.023). Kaplan-Meier survival curves for overall survival (OS) showed a statistically significant difference for patients with c-MYC amplification in full cohort of colorectal cancer, stage III-IV set and patients with lymph node metastasis (P = 0.002, 0.034, 0.012, respectively). Further analysis found c-MYC amplification associated with poorer survival in the subgroup of colorectal cancer with schistosomiasis (CRC-S, P < 0.001), but not in colorectal cancer without schistosomiasis (CRC-NS, P = 0.155). By multivariate analysis, c-MYC amplification was an independent poor-prognostic factor in CRC-S set (P = 0.046). CONCLUSIONS: Our study firstly found c-MYC amplification could predict poor prognosis in schistosomiasis-associated colorectal cancer, but not in colorectal cancer without schistosomiasis.


Assuntos
Neoplasias Colorretais/genética , Neoplasias Colorretais/parasitologia , Amplificação de Genes , Proteínas Proto-Oncogênicas c-myc/genética , Esquistossomose/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/patologia , Feminino , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Estimativa de Kaplan-Meier , Metástase Linfática/patologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos
18.
Nat Commun ; 11(1): 1827, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32286286

RESUMO

It is unclear why some tissues are refractory to the mitogenic effects of the oncogene Myc. Here we show that Myc activation induces rapid transcriptional responses followed by proliferation in some, but not all, organs. Despite such disparities in proliferative response, Myc is bound to DNA at open elements in responsive (liver) and non-responsive (heart) tissues, but fails to induce a robust transcriptional and proliferative response in the heart. Using heart as an exemplar of a non-responsive tissue, we show that Myc-driven transcription is re-engaged in mature cardiomyocytes by elevating levels of the positive transcription elongation factor (P-TEFb), instating a large proliferative response. Hence, P-TEFb activity is a key limiting determinant of whether the heart is permissive for Myc transcriptional activation. These data provide a greater understanding of how Myc transcriptional activity is determined and indicate modification of P-TEFb levels could be utilised to drive regeneration of adult cardiomyocytes for the treatment of heart myopathies.


Assuntos
Miocárdio/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Transcrição Genética , Animais , Proliferação de Células/genética , Cromatina/metabolismo , Ciclina T/metabolismo , Camundongos , Miócitos Cardíacos/metabolismo , Especificidade de Órgãos , Fosforilação , Fator B de Elongação Transcricional Positiva/metabolismo , Ligação Proteica , Proteínas Proto-Oncogênicas c-myc/metabolismo , Ativação Transcricional/genética
19.
Mol Cell ; 78(4): 653-669.e8, 2020 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-32315601

RESUMO

Epstein-Barr virus (EBV) is associated with multiple human malignancies. To evade immune detection, EBV switches between latent and lytic programs. How viral latency is maintained in tumors or in memory B cells, the reservoir for lifelong EBV infection, remains incompletely understood. To gain insights, we performed a human genome-wide CRISPR/Cas9 screen in Burkitt lymphoma B cells. Our analyses identified a network of host factors that repress lytic reactivation, centered on the transcription factor MYC, including cohesins, FACT, STAGA, and Mediator. Depletion of MYC or factors important for MYC expression reactivated the lytic cycle, including in Burkitt xenografts. MYC bound the EBV genome origin of lytic replication and suppressed its looping to the lytic cycle initiator BZLF1 promoter. Notably, MYC abundance decreases with plasma cell differentiation, a key lytic reactivation trigger. Our results suggest that EBV senses MYC abundance as a readout of B cell state and highlights Burkitt latency reversal therapeutic targets.


Assuntos
Linfoma de Burkitt/patologia , Infecções por Vírus Epstein-Barr/virologia , Herpesvirus Humano 4/fisiologia , Interações Hospedeiro-Patógeno , Proteínas Proto-Oncogênicas c-myc/metabolismo , Ativação Viral , Latência Viral , Animais , Linfócitos B/metabolismo , Linfócitos B/patologia , Linfócitos B/virologia , Linfoma de Burkitt/metabolismo , Linfoma de Burkitt/virologia , Proliferação de Células , Infecções por Vírus Epstein-Barr/genética , Infecções por Vírus Epstein-Barr/metabolismo , Feminino , Regulação Viral da Expressão Gênica , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-myc/genética , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
20.
Pediatr Blood Cancer ; 67(7): e28341, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32323914

RESUMO

BACKGROUND: Rearrangements of chromosome 8q24/MYC (8q24/MYC-r), resulting from t(8;14)(q24;q32), t(2;8)(p11;q24), or t(8;22)(q24;q11), are mainly associated with Burkitt lymphoma/leukemia (BL) and rarely observed in patients with B-cell precursor acute lymphoblastic leukemia (BCP-ALL). The characteristics of BCP-ALL with 8q24/MYC-r are poorly understood. PROCEDURE: A retrospective nationwide study of data from patients with pediatric BCP-ALL with 8q24/MYC-r in Japan was conducted to clarify the clinical and biological characteristics associated with 8q24/MYC-r BCP-ALL. RESULTS: Ten patients with BCP-ALL with 8q24/MYC-r, including three with double-hit leukemia (DHL) (two with t(8;14)(q24;q32) and t(14;18)(q32;q21) and one with t(8;14) and t(3;22)(q27;q11)), were identified. Patients with BCP-ALL with 8q24/MYC-r had higher median age and uric acid and lactate dehydrogenase levels, than those without 8q24/MYC-r. All patients were initially treated with ALL-type chemotherapy; however, four, including one with DHL, were switched to BL-type chemotherapy, based on cytogenetic findings. One patient relapsed after standard-risk ALL-type chemotherapy, and two patients with DHL did not attain complete remission with chemotherapy; all three died within 11 months. The other seven patients treated with BL-type or high-risk ALL-type chemotherapy are alive without disease. CONCLUSIONS: The clinical and laboratory features of BL with IG-MYC rearrangement, displaying a BCP immunophenotype (Wagener et al. and Herbrueggen et al. termed it as pre-BLL), are similar to those of BCP-ALL with 8q24/MYC-r. Low-risk ALL-type chemotherapy may not be appropriate for them, and further studies are required to establish an adequate therapeutic strategy. Further studies of DHL to identify new treatment strategies are also needed.


Assuntos
Biomarcadores Tumorais/genética , Cromossomos Humanos Par 8/genética , Rearranjo Gênico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Proteínas Proto-Oncogênicas c-myc/genética , Adolescente , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras B/epidemiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Prognóstico , Estudos Retrospectivos
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