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1.
Anticancer Res ; 40(1): 133-141, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31892561

RESUMO

BACKGROUND/AIM: Aberrant expression of the BMI1 oncogene has been prevalently found in a variety of human cancers, including cervical cancer. Recent studies have shown that PTC209, a specific BMI1 inhibitor, exhibits high potency in inhibiting the growth of colon, breast, oral cancer cells and cancer-initiating cells, indicative of its chemotherapeutic potential. In the current study, we evaluated the inhibitory abilities of PTC209 in cervical cancer cells. MATERIALS AND METHODS: Three cervical cell lines, C33A, HeLa, and SiHa were treated with PTC209. The impacts of PTC209 on BMI1 were investigated using quantitative reverse-transcription PCR assay (qRT-PCR) and western blotting; changes in cell viability, cell cycle distribution, and apoptosis were assessed using cell viability testing, colony formation assay and flow cytometry analyses, respectively. RESULTS: PTC209 exhibited considerably high short-term and long-term cytotoxicities in all tested cervical cancer cell lines regardless of their HPV infection status, TP53 and pRb statuses. PTC209 significantly downregulated the expression of BMI1 in cervical cancer cell lines, and such downregulation led to G0/G1 arrest (p<0.05). Moreover, PTC209 drove more cells into apoptosis (p<0.05). CONCLUSION: PTC209 (BMI1-targeting agents, in general) represents a novel chemotherapeutic agent with potential in cervical cancer therapy.


Assuntos
Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Complexo Repressor Polycomb 1/antagonistas & inibidores , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologia
2.
Nucleic Acids Res ; 47(13): 6668-6684, 2019 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-31114908

RESUMO

Rearrangement of the 1q12 pericentromeric heterochromatin and subsequent amplification of the 1q arm is commonly associated with cancer development and progression and may result from epigenetic deregulation. In many premalignant and malignant cells, loss of 1q12 satellite DNA methylation causes the deposition of polycomb factors and formation of large polycomb aggregates referred to as polycomb bodies. Here, we show that SSX proteins can destabilize 1q12 pericentromeric heterochromatin in melanoma cells when it is present in the context of polycomb bodies. We found that SSX proteins deplete polycomb bodies and promote the unfolding and derepression of 1q12 heterochromatin during replication. This further leads to segregation abnormalities during anaphase and generation of micronuclei. The structural rearrangement of 1q12 pericentromeric heterochromatin triggered by SSX2 is associated with loss of polycomb factors, but is not mediated by diminished polycomb repression. Instead, our studies suggest a direct effect of SSX proteins facilitated though a DNA/chromatin binding, zinc finger-like domain and a KRAB-like domain that may recruit chromatin modifiers or activate satellite transcription. Our results demonstrate a novel mechanism for generation of 1q12-associated genomic instability in cancer cells.


Assuntos
Montagem e Desmontagem da Cromatina , Cromossomos Humanos Par 1/metabolismo , Heterocromatina/metabolismo , Proteínas de Neoplasias/fisiologia , Proteínas Repressoras/fisiologia , Processamento Alternativo , Linhagem Celular Tumoral , DNA de Neoplasias/genética , DNA Satélite/genética , Repressão Epigenética , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Instabilidade Genômica , Humanos , Melanoma/patologia , Proteínas de Neoplasias/genética , Mutação Puntual , Complexo Repressor Polycomb 1/antagonistas & inibidores , Complexo Repressor Polycomb 1/genética , Domínios Proteicos , Dobramento de Proteína , RNA Interferente Pequeno/genética , Proteínas Recombinantes/metabolismo , Proteínas Repressoras/genética , Deleção de Sequência , Transcrição Genética , Dedos de Zinco/fisiologia
3.
J Exp Clin Cancer Res ; 38(1): 25, 2019 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-30658672

RESUMO

BACKGROUND: Glioblastomas (GBM) comprise different subsets that exhibit marked heterogeneity and plasticity, leading to a lack of success of genomic profiling in guiding the development of precision medicine approaches against these tumors. Accordingly, there is an urgent need to investigate the regulatory mechanisms for different GBM subsets and identify novel biomarkers and therapeutic targets relevant in the context of GBM-specific niches. The DHHC family of proteins is associated tightly with the malignant development and progression of gliomas. However, the role of these proteins in the plasticity of GBM subsets remains unclear. METHODS: This study utilized human glioma proneural or mesenchymal stem cells as indicated. The effects of DHHC proteins on different GBM subsets were investigated through in vitro and in vivo assays (i.e., colony formation assay, flow cytometry assay, double immunofluorescence, western blot, and xenograft model). Western blot, co-immunoprecipitation, and liquid chromatograph mass spectrometer-mass spectrometry assays were used to detect the protein complexes of ZDHHC18 and ZDHHC23 in various GBM subtypes, and explore the mechanism of DHHC proteins in targeting different subsets of GSCs in specific niches. RESULTS: ZDHHC18 and ZDHHC23 could target the glioma stem cells of different GBM subsets in the context of their specific niches and regulate the cellular plasticity of these subtypes. Moreover, mechanistic investigations revealed that ZDHHC18 and ZDHHC23 competitively interact with a BMI1 E3 ligase, RNF144A, to regulate the polyubiquitination and accumulation of BMI1. These events contributed to the transition of glioma stem cells in GBM and cell survival under the stressful tumor microenvironment. CONCLUSIONS: Our work highlights the role of DHHC proteins in the plasticity of GBM subsets and reveals that BMI1 represents a potential therapeutic target for human gliomas.


Assuntos
Aciltransferases/genética , Glioma/genética , Glioma/patologia , Família Multigênica , Células-Tronco Neoplásicas/metabolismo , Microambiente Tumoral/genética , Aciltransferases/metabolismo , Biomarcadores Tumorais , Inibidores Enzimáticos , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Glioma/metabolismo , Glioma/mortalidade , Humanos , Modelos Biológicos , Gradação de Tumores , Células-Tronco Neoplásicas/patologia , Complexo Repressor Polycomb 1/antagonistas & inibidores
4.
Oncogene ; 38(10): 1702-1716, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30348991

RESUMO

Medulloblastoma (MB) is the most frequent malignant pediatric brain tumor, representing 20% of newly diagnosed childhood central nervous system malignancies. Although advances in multimodal therapy yielded a 5-year survivorship of 80%, MB still accounts for the leading cause of childhood cancer mortality. In this work, we describe the epigenetic regulator BMI1 as a novel therapeutic target for the treatment of recurrent human Group 3 MB, a childhood brain tumor for which there is virtually no treatment option beyond palliation. Current clinical trials for recurrent MB patients based on genomic profiles of primary, treatment-naive tumors will provide limited clinical benefit since recurrent metastatic MBs are highly genetically divergent from their primary tumor. Using a small molecule inhibitor against BMI1, PTC-028, we were able to demonstrate complete ablation of self-renewal of MB stem cells in vitro. When administered to mice xenografted with patient tumors, we observed significant reduction in tumor burden in both local and metastatic compartments and subsequent increased survival, without neurotoxicity. Strikingly, serial in vivo re-transplantation assays demonstrated a marked reduction in tumor initiation ability of recurrent MB cells upon re-transplantation of PTC-028-treated cells into secondary recipient mouse brains. As Group 3 MB is often metastatic and uniformly fatal at recurrence, with no current or planned trials of targeted therapy, an efficacious targeted agent would be rapidly transitioned to clinical trials.


Assuntos
Neoplasias Cerebelares/tratamento farmacológico , Meduloblastoma/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Complexo Repressor Polycomb 1/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/administração & dosagem , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias Cerebelares/genética , Neoplasias Cerebelares/metabolismo , Criança , Epigênese Genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Meduloblastoma/genética , Meduloblastoma/metabolismo , Camundongos , Células-Tronco Neoplásicas/citologia , Células-Tronco Neoplásicas/metabolismo , Complexo Repressor Polycomb 1/genética , Bibliotecas de Moléculas Pequenas/farmacologia , Resultado do Tratamento , Regulação para Cima/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
5.
PLoS Pathog ; 14(9): e1007267, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30212584

RESUMO

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of three human malignancies, the endothelial cell cancer Kaposi's sarcoma, and two B cell cancers, Primary Effusion Lymphoma and multicentric Castleman's disease. KSHV has latent and lytic phases of the viral life cycle, and while both contribute to viral pathogenesis, lytic proteins contribute to KSHV-mediated oncogenesis. Reactivation from latency is driven by the KSHV lytic gene transactivator RTA, and RTA transcription is controlled by epigenetic modifications. To identify host chromatin-modifying proteins that are involved in the latent to lytic transition, we screened a panel of inhibitors that target epigenetic regulatory proteins for their ability to stimulate KSHV reactivation. We found several novel regulators of viral reactivation: an inhibitor of Bmi1, PTC-209, two additional histone deacetylase inhibitors, Romidepsin and Panobinostat, and the bromodomain inhibitor (+)-JQ1. All of these compounds stimulate lytic gene expression, viral genome replication, and release of infectious virions. Treatment with Romidepsin, Panobinostat, and PTC-209 induces histone modifications at the RTA promoter, and results in nucleosome depletion at this locus. Finally, silencing Bmi1 induces KSHV reactivation, indicating that Bmi1, a member of the Polycomb repressive complex 1, is critical for maintaining KSHV latency.


Assuntos
Montagem e Desmontagem da Cromatina/fisiologia , Herpesvirus Humano 8/fisiologia , Ativação Viral/fisiologia , Latência Viral/fisiologia , Linhagem Celular , Montagem e Desmontagem da Cromatina/efeitos dos fármacos , Montagem e Desmontagem da Cromatina/genética , Depsipeptídeos/farmacologia , Epigênese Genética/efeitos dos fármacos , Genoma Viral/efeitos dos fármacos , Herpesvirus Humano 8/genética , Herpesvirus Humano 8/patogenicidade , Compostos Heterocíclicos com 2 Anéis/farmacologia , Inibidores de Histona Desacetilases/farmacologia , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/fisiologia , Humanos , Proteínas Imediatamente Precoces/genética , Proteínas Imediatamente Precoces/fisiologia , Panobinostat/farmacologia , Complexo Repressor Polycomb 1/antagonistas & inibidores , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/fisiologia , Regiões Promotoras Genéticas , Interferência de RNA , Tiazóis/farmacologia , Transativadores/genética , Transativadores/fisiologia , Ativação Viral/efeitos dos fármacos , Ativação Viral/genética , Latência Viral/genética
6.
Clin Cancer Res ; 24(24): 6421-6432, 2018 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-30087142

RESUMO

PURPOSE: Metastasis is the major cause of mortality in prostate cancer patients. Factors such as genetic makeup and race play critical role in the outcome of therapies. This study was conducted to investigate the relevance of BMI1 in metastatic prostate cancer disease in Caucasian and African-Americans. EXPERIMENTAL DESIGN: We employed race-specific prostate cancer models, clinical specimens, clinical data mining, gene-microarray, transcription-reporter assay, chromatin-immunoprecipitation (ChIP), IHC, transgenic-(tgfl/fl) zebrafish, and mouse metastasis models. RESULTS: BMI1 expression was observed to be elevated in metastatic tumors (lymph nodes, lungs, bones, liver) of Caucasian and African-American prostate cancer patients. The comparative analysis of stage III/IV tumors showed an increased BMI1 expression in African-Americans than Caucasians. TCGA and NIH/GEO clinical data corroborated to our findings. We show that BMI1 expression (i) positively correlates to metastatic (MYC, VEGF, cyclin D1) and (ii) negative correlates to tumor suppressor (INKF4A/p16, PTEN) levels in tumors. The correlation was prominent in African-American tumors. We show that BMI1 regulates the transcriptional activation of MYC, VEGF, INKF4A/p16, and PTEN. We show the effect of pharmacological inhibition of BMI1 on the metastatic genome and invasiveness of tumor cells. Next, we show the anti-metastatic efficacy of BMI1-inhibitor in transgenic zebrafish and mouse metastasis models. Docetaxel as monotherapy has poor outcome on the growth of metastatic tumors. BMI1 inhibitor as an adjuvant improved the taxane therapy in race-based in vitro and in vivo models. CONCLUSIONS: BMI1, a major driver of metastasis, represents a promising therapeutic target for treating advanced prostate cancer in patients (including those belonging to high-risk group).


Assuntos
Afro-Americanos , Biomarcadores Tumorais , Complexo Repressor Polycomb 1/genética , Neoplasias da Próstata/genética , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Modelos Animais de Doenças , Docetaxel/farmacologia , Grupo com Ancestrais do Continente Europeu , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos , Terapia de Alvo Molecular , Metástase Neoplásica , Estadiamento de Neoplasias , Complexo Repressor Polycomb 1/antagonistas & inibidores , Complexo Repressor Polycomb 1/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Peixe-Zebra
7.
Mol Cancer Ther ; 17(10): 2136-2143, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30026381

RESUMO

With rising incidence rates, endometrial cancer is one of the most common gynecologic malignancies in the United States. Although surgery provides significant survival benefit to early-stage patients, those with advanced or recurrent metastatic disease have a dismal prognosis. Limited treatment options include chemotherapy and radiotherapy. Hence, there is a compelling need for developing molecularly targeted therapy. Here, we show that the polycomb ring finger protein BMI1, also known as a stem cell factor, is significantly overexpressed in endometrial cancer cell lines, endometrial cancer patient tissues as well as in nonendometrioid histologies and associated with poor overall survival. PTC-028, a second-generation inhibitor of BMI1 function, decreases invasion of endometrial cancer cells and potentiates caspase-dependent apoptosis, while normal cells with minimal expression of BMI1 remain unaffected. In an aggressive uterine carcinosarcoma xenograft model, single-agent PTC-028 significantly delayed tumor growth and increased tumor doubling time compared with the standard carboplatin/paclitaxel therapy. Therefore, anti-BMI1 strategies may represent a promising targeted approach in patients with advanced or recurrent endometrial cancer, a population where treatment options are limited. Mol Cancer Ther; 17(10); 2136-43. ©2018 AACR.


Assuntos
Antineoplásicos/farmacologia , Neoplasias do Endométrio/metabolismo , Complexo Repressor Polycomb 1/antagonistas & inibidores , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Apoptose/efeitos dos fármacos , Caspases/metabolismo , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Neoplasias do Endométrio/tratamento farmacológico , Neoplasias do Endométrio/mortalidade , Neoplasias do Endométrio/patologia , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Cell Cycle ; 17(10): 1199-1211, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29886801

RESUMO

Glioblastoma multiforme (GBM) is the most common and aggressive brain tumor and refractory to existing therapies. The oncogene BMI-1, a member of Polycomb Repressive Complex 1 (PRC1) plays essential roles in various human cancers and becomes an attractive therapeutic target. Here we showed that BMI-1 is highly expressed in GBM and especially enriched in glioblastoma stem cells (GSCs). Then we comprehensively investigated the anti-GBM effects of PTC-209, a novel specific inhibitor of BMI-1. We found that PTC-209 efficiently downregulates BMI-1 expression and the histone H2AK119ub1 levels at microM concentrations. In vitro, PTC-209 effectively inhibits glioblastoma cell proliferation and migration, and GSC self-renewal. Transcriptomic analyses of TCGA datasets of glioblastoma and PTC-209-treated GBM cells demonstrate that PTC-209 reverses the altered transcriptional program associated with BMI-1 overexpression. And Chromatin Immunoprecipitation assay confirms that the derepressed tumor suppressor genes belong to BMI-1 targets and the enrichment levels of H2AK119ub1 at their promoters is decreased upon PTC-209 treatment. Strikingly, the glioblastoma growth is significantly attenuated by PTC-209 in a murine orthotopic xenograft model. Therefore our study provides proof-of-concept for inhibitors targeting BMI-1 in potential applications as an anti-GBM therapy.


Assuntos
Neoplasias Encefálicas/patologia , Carcinogênese/patologia , Glioblastoma/patologia , Compostos Heterocíclicos com 2 Anéis/farmacologia , Terapia de Alvo Molecular , Complexo Repressor Polycomb 1/antagonistas & inibidores , Tiazóis/farmacologia , Animais , Neoplasias Encefálicas/genética , Carcinogênese/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Autorrenovação Celular/efeitos dos fármacos , Progressão da Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Genes Supressores de Tumor , Glioblastoma/genética , Compostos Heterocíclicos com 2 Anéis/química , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Regiões Promotoras Genéticas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Tiazóis/química , Transcrição Genética/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética
9.
Comput Biol Chem ; 74: 339-346, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29723807

RESUMO

Polycomb CBX proteins regulate gene expression by targeting Polycomb repressive complex 1 (PRC1) to sites of H3K27me3 via their chromodomains, which plays a key role in the development of numerous cancers. UNC3866, is a recently reported peptide-based inhibitor of the methyllysine (Kme) reading function of CBX chromodomains (CBX2, 4 and 6-8). The previous experiments showed that UNC3866 bound the chromodomains of CBX7 strongly, with ∼20-fold selectivity over other CBX chromodomains. However, the potential mechanism of UNC3866 preferentially binding to CBX7 is still unknown. In this study, we performed two pairs of microsecond molecular dynamic simulations (CBX2 (-UNC3866)) and (CBX7 (-UNC3866)) to study the inhibition and isoform-selective mechanism of UNC3866 to CBX7. The conformational analysis of apo- and holo- CBX2 and CBX7 indicated that the aromatic cage of CBX7 protein was more prone to be induced by UNC3866 relative to CBX2 protein. The results of predicted binding free energy suggested the binding affinity of UNC3866 with CBX7 was stronger than that with CBX2, because of the lower binding free energy of the former. Furthermore, the energetic origin of UNC3866 selective for CBX7 protein mainly came from the higher van der Waals contributions. The binding mode analysis showed that Asn47 of CBX2 formed a hydrogen bond with the OH group of C-terminal cap of UNC3866, inducing the conformational changes of diethyllysine of UNC3866 that is obviously different from that in CBX7. Additionally, His39 in CBX2 chromodomain interrupted the structured aromatic cage, partly explaining the reason for UNC3866 preferring for binding to CBX7. The proposal of this selective mechanism could be helpful for the rational design of novel selective inhibitors of the Polycomb CBX protein.


Assuntos
Simulação de Dinâmica Molecular , Oligopeptídeos/farmacologia , Complexo Repressor Polycomb 1/antagonistas & inibidores , Análise por Conglomerados , Humanos , Conformação Molecular , Oligopeptídeos/química , Complexo Repressor Polycomb 1/metabolismo , Relação Estrutura-Atividade , Termodinâmica
10.
Nanomedicine ; 14(7): 2009-2021, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29842934

RESUMO

Resistance of hepatocellular carcinoma (HCC) to systemic chemotherapy is partially due to presence of drug-resistant cancer stem cells. Bmi1 protein is essential for survival and proliferation of HCC cancer stem cells (CSCs). Here, we report that Bmi1 siRNA (Bmi1siR) loaded in cationic nanocapsules of cisplatin (NPC) eliminated stem cells in situ HCC in mice. NPC/Bmi1siR was fabricated via electrostatic complexation of Bmi1 siRNA to NPCs, which had cores composed of cisplatin and were coated with cationic lipids. In vivo, NPC/Bmi1siR showed higher anti-tumor activity in HCC bearing mice compared with cisplatin or NPC. Critically, both flow cytometry (FACS) analysis in vitro and histological examination in vivo revealed that side population or CD133+ HCC cells were dramatically decreased by NPC/Bmi1siR treatment, suggesting that HCC CSCs were eliminated. Altogether, our results suggest that drug resistance of HCC can be overcome by co-delivering Bmi1 siRNA with cisplatin in cationic nanocapsules.


Assuntos
Carcinoma Hepatocelular/terapia , Cisplatino/administração & dosagem , Neoplasias Hepáticas/terapia , Nanocápsulas/administração & dosagem , Células-Tronco Neoplásicas/efeitos dos fármacos , Complexo Repressor Polycomb 1/antagonistas & inibidores , RNA Interferente Pequeno/genética , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Apoptose , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Cátions , Ciclo Celular , Proliferação de Células , Cisplatino/farmacologia , Terapia Combinada , Resistencia a Medicamentos Antineoplásicos , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Nanocápsulas/química , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Complexo Repressor Polycomb 1/genética , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
11.
J Ovarian Res ; 11(1): 31, 2018 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-29685168

RESUMO

BACKGROUND: B-cell-specific Moloney murine leukemia virus integration site 1 (BMI1) might be an appropriate biomarker in the management of epithelial ovarian cancer (EOC). However, the biological role of BMI1 and its relevant molecular mechanism needs further elaboration. Clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system is an excellent genome-editing tool and is scarcely used in EOC studies. METHODS: We first applied CRISPR/Cas9 technique to silence BMI1 in EOC cells; thereafter we accomplished various in vivo and in vitro experiments to detect biological behaviors of ovarian cancer cells, including MTT, flow cytometry, Transwell, real-time polymerase chain reaction and western blotting assays, etc.; eventually, we used RNA sequencing to reveal the underlying molecular traits driven by BMI1 in EOC. RESULTS: We successfully shut off the expression of BMI1 in EOC cells using CRISPR/Cas9 system, providing an ideal cellular model for investigations of target gene. Silencing BMI1 could reduce cell growth and metastasis, promote cell apoptosis, and enhance the platinum sensitivity of EOC cells. BMI1 might alter extracellular matrix structure and angiogenesis of tumor cells through regulating Focal adhesion and PI3K/AKT pathways. CONCLUSION: BMI1 is a potential biomarker in EOC management, especially for tumor progression and chemo-resistance. Molecular traits, including BMI1 and core genes in Focal adhesion and PI3K/AKT pathways, might be alternatives as therapeutic targets for EOC.


Assuntos
Sistemas CRISPR-Cas , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Neoplasias Epiteliais e Glandulares/genética , Neoplasias Ovarianas/genética , Complexo Repressor Polycomb 1/genética , Animais , Apoptose , Carcinoma Epitelial do Ovário , Linhagem Celular Tumoral , Movimento Celular/genética , Citometria de Fluxo , Adesões Focais/genética , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Humanos , Camundongos , Invasividade Neoplásica/genética , Neoplasias Epiteliais e Glandulares/patologia , Neoplasias Ovarianas/patologia , Complexo Repressor Polycomb 1/antagonistas & inibidores , Análise de Sequência de RNA , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Cell Physiol Biochem ; 46(3): 1055-1064, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29669323

RESUMO

BACKGROUND/AIMS: Long noncoding RNAs (lncRNAs) are a novel class of protein-noncoding transcripts that are aberrantly expressed in multiple diseases including cancers. LINC00152 has been identified as an oncogene involved in many kinds of cancer; however, its expression pattern and function in human glioma remain unclear. METHODS: Quantitative real-time polymerase chain reaction was carried out to measure LINC00152 expression in human glioma cell lines and tissues. CCK-8 and EdU assays were performed to assess cell proliferation, and scratch assays and Transwell assays were used to assess cell migration and invasion, respectively. Luciferase reporter assays were carried out to determine the interaction between miR-16 and LINC00152. In vivo experiments were conducted to assess tumor formation. RESULTS: LINC00152 was found to be significantly upregulated in human glioma cell lines and clinical samples. Knockdown of LINC00152 suppressed glioma cell proliferation, migration, and invasion in vitro. In vivo assays in nude mice confirmed that LINC00152 knockdown inhibits tumor growth. Furthermore, mechanistic investigation showed that LINC00152 binds to miR-16 in a sequence-specific manner and suppresses its expression. miR-16 inhibition strongly attenuated LINC00152 knockdown-mediated suppressive effects on proliferation, migration, and invasion. Moreover, LINC00152 induced BMI1 expression by sponging miR-16; this effect further promoted glioma cell proliferation and invasion. CONCLUSION: We regard LINC00152 as an oncogenic lncRNA promoting glioma cell proliferation and invasion and as a potential target for human glioma treatment.


Assuntos
MicroRNAs/metabolismo , RNA Longo não Codificante/metabolismo , Animais , Antagomirs/metabolismo , Astrócitos/citologia , Astrócitos/metabolismo , Sequência de Bases , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Glioma/genética , Glioma/metabolismo , Glioma/patologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , Complexo Repressor Polycomb 1/antagonistas & inibidores , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Interferência de RNA , RNA Longo não Codificante/antagonistas & inibidores , RNA Longo não Codificante/genética , RNA Interferente Pequeno/metabolismo , Alinhamento de Sequência , Transplante Heterólogo , Regulação para Cima
13.
Cell Death Differ ; 25(9): 1598-1611, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29459770

RESUMO

Neurons in the central nervous system (CNS) lose their intrinsic ability and fail to regenerate, but the underlying mechanisms are largely unknown. Polycomb group (PcG) proteins, which include PRC1 and PRC2 complexes function as gene repressors and are involved in many biological processes. Here we report that PRC1 components (polycomb chromobox (CBX) 2, 7, and 8) are novel regulators of axon growth and regeneration. Especially, knockdown of CBX7 in either embryonic cortical neurons or adult dorsal root ganglion (DRG) neurons enhances their axon growth ability. Two important transcription factors GATA4 and SOX11 are functional downstream targets of CBX7 in controlling axon regeneration. Moreover, knockdown of GATA4 or SOX11 in cultured DRG neurons inhibits axon regeneration response from CBX7 downregulation in DRG neurons. These findings suggest that targeting CBX signaling pathway may be a novel approach for promoting the intrinsic regenerative capacity of damaged CNS neurons.


Assuntos
Axônios/fisiologia , Proteínas do Grupo Polycomb/metabolismo , Animais , Células Cultivadas , Regulação para Baixo , Fator de Transcrição GATA4/antagonistas & inibidores , Fator de Transcrição GATA4/genética , Fator de Transcrição GATA4/metabolismo , Gânglios Espinais/citologia , Camundongos , Neurônios/citologia , Neurônios/metabolismo , Complexo Repressor Polycomb 1/antagonistas & inibidores , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Proteínas do Grupo Polycomb/antagonistas & inibidores , Proteínas do Grupo Polycomb/genética , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Regeneração , Fatores de Transcrição SOXC/antagonistas & inibidores , Fatores de Transcrição SOXC/genética , Fatores de Transcrição SOXC/metabolismo , Nervo Isquiático/lesões
14.
Biochem Biophys Res Commun ; 496(2): 468-474, 2018 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-29337063

RESUMO

Aberrant activation of Wnt signaling plays a critical role in the development of colon cancer. BMI, a component of the polycomb repressive complex (PRC1), is upregulated in various types of cancer and contributes to epigenetic silencing of tumor suppressors. In this study, we showed that BMI1 is upregulated in colon cancer tissues and cell lines. Overexpression of BMI1 in primary epithelial colon cells promotes cellular growth and activates WNT pathway, while BMI1 silencing in colon cancer cells represses these effects. We also found that BMI1 binds to the promoter of IDAX, a Wnt antagonist, and decreases its transcription. Expression of IDAX is downregulated in colon cancer tissues and cell lines and negatively correlated with BMI1 in colon cancer tissues. Furthermore, Silencing of IDAX counteracts the effects of BMI1 suppression, while its overexpression reverses oncogenic effects of BMI1. Together, these findings indicate that BMI1-mediated IDAX epigenetic suppression is crucial for enhancement of colon carcinogenesis, suggesting that BMI1∖IDAX axis as a potential novel diagnostic and therapeutic target of colon cancer.


Assuntos
Carcinogênese/genética , Neoplasias do Colo/genética , Proteínas de Ligação a DNA/genética , Regulação Neoplásica da Expressão Gênica , Complexo Repressor Polycomb 1/genética , Fatores de Transcrição/genética , Via de Sinalização Wnt , Carcinogênese/metabolismo , Carcinogênese/patologia , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Proteínas de Ligação a DNA/metabolismo , Epigênese Genética , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Humanos , Complexo Repressor Polycomb 1/antagonistas & inibidores , Complexo Repressor Polycomb 1/metabolismo , Cultura Primária de Células , Regiões Promotoras Genéticas , Ligação Proteica , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Fatores de Transcrição/metabolismo
15.
Mol Cancer Ther ; 17(1): 39-49, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29158468

RESUMO

BMI-1, also known as a stem cell factor, is frequently upregulated in several malignancies. Elevated expression of BMI-1 correlates with poor prognosis and is therefore considered a viable therapeutic target in a number of malignancies including ovarian cancer. Realizing the immense pathologic significance of BMI-1, small-molecule inhibitors against BMI-1 are recently being developed. In this study, we functionally characterize PTC-028, an orally bioavailable compound that decreases BMI-1 levels by posttranslational modification. We report that PTC-028 treatment selectively inhibits cancer cells in clonal growth and viability assays, whereas normal cells remain unaffected. Mechanistically, hyperphosphorylation-mediated depletion of cellular BMI-1 by PTC-028 coupled with a concurrent temporal decrease in ATP and a compromised mitochondrial redox balance potentiates caspase-dependent apoptosis. In vivo, orally administered PTC-028, as a single agent, exhibits significant antitumor activity comparable with the standard cisplatin/paclitaxel therapy in an orthotopic mouse model of ovarian cancer. Thus, PTC-028 has the potential to be used as an effective therapeutic agent in patients with epithelial ovarian cancer, where treatment options are limited. Mol Cancer Ther; 17(1); 39-49. ©2017 AACR.


Assuntos
Benzimidazóis/farmacologia , Carcinoma Epitelial do Ovário/tratamento farmacológico , Complexo Repressor Polycomb 1/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Pirazinas/farmacologia , Animais , Antineoplásicos/farmacologia , Carcinoma Epitelial do Ovário/metabolismo , Carcinoma Epitelial do Ovário/patologia , Linhagem Celular Tumoral , Feminino , Humanos , Camundongos , Camundongos Nus , Complexo Repressor Polycomb 1/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Anticancer Res ; 37(11): 6047-6053, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-29061784

RESUMO

BACKGROUND/AIM: B cell-specific Moloney murine leukemia virus integration site 1 (BMI1) is up-regulated in several cancers; therefore, we investigated the effects of BMI1 inhibitors on leukemia cells. MATERIALS AND METHODS: Four acute myeloid leukemia and two T-lymphoblastic leukemia cell lines were treated with BMI1 inhibitors artemisinin, PRT4165, and PTC-209 and analyzed for cell proliferation and gene expression by microarray and immunoblotting. RESULTS: PTC-209 and PRT4165 suppressed the growth of all cell lines through apoptosis.Artemisinin acted only on Jurkat cells. BMI1 inhibitors and BMI1-specific siRNA down-regulated the expression of NOTCH signaling proteins NOTCH1, HES1, and MYC. All but one cell lines did not have the cyclin-dependent kinase inhibitor 2A (CDKN2A) gene targeted by BMI1, thus the inhibitors acted through CDKN2A-independent pathways. CONCLUSION: BMI1 inhibition suppressed proliferation of leukemia cells through NOTCH signaling which functions downstream of BMI1, suggesting that BMI1 inhibitors can be candidate targeted drugs against leukemia.


Assuntos
Proliferação de Células/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Compostos Heterocíclicos com 2 Anéis/farmacologia , Leucemia Mieloide Aguda/patologia , Leucemia de Células T/patologia , Complexo Repressor Polycomb 1/antagonistas & inibidores , Receptores Notch/antagonistas & inibidores , Tiazóis/farmacologia , Apoptose/efeitos dos fármacos , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/metabolismo , Leucemia de Células T/tratamento farmacológico , Leucemia de Células T/metabolismo , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , RNA Interferente Pequeno/genética , Receptores Notch/genética , Receptores Notch/metabolismo , Transdução de Sinais/efeitos dos fármacos , Células Tumorais Cultivadas
17.
Mol Med Rep ; 16(6): 7949-7958, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28983587

RESUMO

Bone cancer is one of the most lethal malignancies and the specific causes of tumor initiation are not well understood. B­cell­specific Moloney murine leukemia virus integration site 1 protein (Bmi­1) has been reported to be associated with the initiation and progression of osteosarcoma, and as a prognostic indicator in the clinic. In the current study, a full­length antibody targeting Bmi­1 (AbBmi­1) was produced and the preclinical value of Bmi­1­targeted therapy was evaluated in bone carcinoma cells and tumor xenograft mice. The results indicated that the Bmi­1 expression level was markedly upregulated in bone cancer cell lines, and inhibition of Bmi­1 by AbBmi­1 reduced the invasiveness and migration of osteosarcoma cells. Overexpression of Bmi­1 promoted proliferation and angiogenesis, and increased apoptosis resistance induced by cisplatin via the nuclear factor­κB (NF­κB) signal pathway. In addition, AbBmi­1 treatment inhibited the tumorigenicity of osteosarcoma cells in vivo. Furthermore, AbBmi­1 blocked NF­κB signaling and reduced MMP­9 expression. Furthermore, Bmi­1 promoted osteosarcoma tumor growth, whereas AbBmi­1 significantly inhibited osteosarcoma tumor growth in vitro and in vivo. Notably, AbBmi­1 decreased the percentages of Ki67­positive cells and terminal deoxynucleotidyl transferase dUTP nick end labeling­positive cells in tumors compared with Bmi­1­treated and PBS controls. Notably, MMP­9 and NF­κB expression were downregulated by treatment with AbBmi­1 in MG­63 osteosarcoma cells. In conclusion, the data provides evidence that AbBmi­1 inhibited the progression of osteosarcoma, suggesting that AbBmi­1 may be a novel anti­cancer agent through the inhibition of Bmi­1 via activating the NF­κB pathway in osteosarcoma.


Assuntos
Antineoplásicos Imunológicos/farmacologia , Neoplasias Ósseas/genética , Neoplasias Ósseas/metabolismo , NF-kappa B/metabolismo , Osteossarcoma/genética , Osteossarcoma/metabolismo , Complexo Repressor Polycomb 1/genética , Transdução de Sinais/efeitos dos fármacos , Animais , Anticorpos Monoclonais/farmacologia , Apoptose/genética , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/patologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Modelos Animais de Doenças , Feminino , Humanos , Metaloproteinase 9 da Matriz/metabolismo , Terapia de Alvo Molecular , Osteossarcoma/tratamento farmacológico , Osteossarcoma/patologia , Complexo Repressor Polycomb 1/antagonistas & inibidores , Complexo Repressor Polycomb 1/metabolismo
18.
Nat Med ; 23(11): 1352-1361, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29035367

RESUMO

Glioblastomas are lethal cancers defined by angiogenesis and pseudopalisading necrosis. Here, we demonstrate that these histological features are associated with distinct transcriptional programs, with vascular regions showing a proneural profile, and hypoxic regions showing a mesenchymal pattern. As these regions harbor glioma stem cells (GSCs), we investigated the epigenetic regulation of these two niches. Proneural, perivascular GSCs activated EZH2, whereas mesenchymal GSCs in hypoxic regions expressed BMI1 protein, which promoted cellular survival under stress due to downregulation of the E3 ligase RNF144A. Using both genetic and pharmacologic inhibition, we found that proneural GSCs are preferentially sensitive to EZH2 disruption, whereas mesenchymal GSCs are more sensitive to BMI1 inhibition. Given that glioblastomas contain both proneural and mesenchymal GSCs, combined EZH2 and BMI1 targeting proved more effective than either agent alone both in culture and in vivo, suggesting that strategies that simultaneously target multiple epigenetic regulators within glioblastomas may be effective in overcoming therapy resistance caused by intratumoral heterogeneity.


Assuntos
Neoplasias Encefálicas/patologia , Proteína Potenciadora do Homólogo 2 de Zeste/antagonistas & inibidores , Glioblastoma/patologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Complexo Repressor Polycomb 1/antagonistas & inibidores , Animais , Epigênese Genética , Humanos , Camundongos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
19.
Sci Rep ; 7(1): 7502, 2017 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-28790310

RESUMO

To determine whether p16 INK4a deletion ameliorated renal tubulointerstitial injury by inhibiting a senescence-associated secretory phenotype (SASP) in Bmi-1-deficient (Bmi-1 -/-) mice, renal phenotypes were compared among 5-week-old Bmi-1 and p16 INK4a double-knockout, and Bmi-1 -/- and wild-type mice. Fifth-passage renal interstitial fibroblasts (RIFs) from the three groups were analyzed for senescence and proliferation. The effect of Bmi-1 deficiency on epithelial-to-mesenchymal transition (EMT) was examined in Bmi-1-knockdown human renal proximal tubular epithelial (HK2) cells, which were treated with concentrated conditioned medium (CM) from the fifth-passage renal interstitial fibroblasts (RIFs) of above three group mice or with exogenous TGF-ß1. Our results demonstrated that p16 INK4a deletion largely rescued renal aging phenotypes caused by Bmi-1 deficiency, including impaired renal structure and function, decreased proliferation, increased apoptosis, senescence and SASP, DNA damage, NF-κB and TGF-ß1/Smad signal activation, inflammatory cell infiltration, and tubulointerstitial fibrosis and tubular atrophy. P16 INK4a deletion also promoted proliferation, reduced senescence and SASP of RIFs and subsequently inhibited EMT of Bmi-1-knockdown HK2 cells. TGF-ß1 further induced the EMT of Bmi-1-knockdown HK2 cells. Thus, p16 INK4a positive senescent cells would be a therapeutic target for preventing renal tubulointerstitial injury.


Assuntos
Lesão Renal Aguda/genética , Inibidor p16 de Quinase Dependente de Ciclina/genética , Células Epiteliais/metabolismo , Transição Epitelial-Mesenquimal/genética , Fibroblastos/metabolismo , Nefrite Intersticial/genética , Complexo Repressor Polycomb 1/genética , Lesão Renal Aguda/metabolismo , Lesão Renal Aguda/patologia , Lesão Renal Aguda/prevenção & controle , Animais , Linhagem Celular Transformada , Proliferação de Células , Senescência Celular , Técnicas de Cocultura , Meios de Cultivo Condicionados/farmacologia , Inibidor p16 de Quinase Dependente de Ciclina/deficiência , Células Epiteliais/patologia , Fibroblastos/patologia , Regulação da Expressão Gênica , Humanos , Túbulos Renais Proximais/metabolismo , Túbulos Renais Proximais/patologia , Camundongos , Camundongos Knockout , NF-kappa B/genética , NF-kappa B/metabolismo , Nefrite Intersticial/metabolismo , Nefrite Intersticial/patologia , Nefrite Intersticial/prevenção & controle , Complexo Repressor Polycomb 1/antagonistas & inibidores , Complexo Repressor Polycomb 1/deficiência , Complexo Repressor Polycomb 1/metabolismo , Proteínas Proto-Oncogênicas/deficiência , Proteínas Proto-Oncogênicas/genética , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Proteínas Smad/genética , Proteínas Smad/metabolismo , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo , Fator de Crescimento Transformador beta1/farmacologia
20.
Target Oncol ; 12(4): 449-462, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28589491

RESUMO

BACKGROUND: Hepatocellular carcinoma (HCC) represents one of the most lethal cancers worldwide due to therapy resistance and disease recurrence. Tumor relapse following treatment could be driven by the persistence of liver cancer stem-like cells (CSCs). The protein BMI1 is a member of the polycomb epigenetic factors governing cellular self-renewal, proliferation, and stemness maintenance. BMI1 expression also correlates with poor patient survival in various cancer types. OBJECTIVE: We aimed to elucidate the extent to which BMI1 can be used as a potential therapeutic target for CSC eradication in HCC. METHODS: We have recently participated in characterizing the first known pharmacological small molecule inhibitor of BMI1. Here, we synthesized a panel of novel BMI1 inhibitors and examined their ability to alter cellular growth and eliminate cancer progenitor/stem-like cells in HCC with different p53 backgrounds. RESULTS: Among various molecules examined, RU-A1 particularly downregulated BMI1 expression, impaired cell viability, reduced cell migration, and sensitized HCC cells to 5-fluorouracil (5-FU) in vitro. Notably, long-term analysis of HCC survival showed that, unlike chemotherapy, RU-A1 effectively reduced CSC content, even as monotherapy. BMI1 inhibition with RU-A1 diminished the number of stem-like cells in vitro more efficiently than the model compound C-209, as demonstrated by clonogenic assays and impairment of CSC marker expression. Furthermore, xenograft assays in zebrafish showed that RU-A1 abrogated tumor growth in vivo. CONCLUSIONS: This study demonstrates the ability to identify agents with the propensity for targeting CSCs in HCC that could be explored as novel treatments in the clinical setting.


Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Complexo Repressor Polycomb 1/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Antineoplásicos/química , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Células HEK293 , Células Hep G2 , Humanos , Imuno-Histoquímica , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Complexo Repressor Polycomb 1/biossíntese , Complexo Repressor Polycomb 1/genética , Bibliotecas de Moléculas Pequenas/química , Ensaios Antitumorais Modelo de Xenoenxerto , Peixe-Zebra
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