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1.
Gastroenterology ; 159(6): 2146-2162.e33, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32805281

RESUMO

BACKGROUND & AIMS: Chromosomal instability (CIN) is a carcinogenesis event that promotes metastasis and resistance to therapy by unclear mechanisms. Expression of the colon cancer-associated transcript 2 gene (CCAT2), which encodes a long noncoding RNA (lncRNA), associates with CIN, but little is known about how CCAT2 lncRNA regulates this cancer enabling characteristic. METHODS: We performed cytogenetic analysis of colorectal cancer (CRC) cell lines (HCT116, KM12C/SM, and HT29) overexpressing CCAT2 and colon organoids from C57BL/6N mice with the CCAT2 transgene and without (controls). CRC cells were also analyzed by immunofluorescence microscopy, γ-H2AX, and senescence assays. CCAT2 transgene and control mice were given azoxymethane and dextran sulfate sodium to induce colon tumors. We performed gene expression array and mass spectrometry to detect downstream targets of CCAT2 lncRNA. We characterized interactions between CCAT2 with downstream proteins using MS2 pull-down, RNA immunoprecipitation, and selective 2'-hydroxyl acylation analyzed by primer extension analyses. Downstream proteins were overexpressed in CRC cells and analyzed for CIN. Gene expression levels were measured in CRC and non-tumor tissues from 5 cohorts, comprising more than 900 patients. RESULTS: High expression of CCAT2 induced CIN in CRC cell lines and increased resistance to 5-fluorouracil and oxaliplatin. Mice that expressed the CCAT2 transgene developed chromosome abnormalities, and colon organoids derived from crypt cells of these mice had a higher percentage of chromosome abnormalities compared with organoids from control mice. The transgenic mice given azoxymethane and dextran sulfate sodium developed more and larger colon polyps than control mice given these agents. Microarray analysis and mass spectrometry indicated that expression of CCAT2 increased expression of genes involved in ribosome biogenesis and protein synthesis. CCAT2 lncRNA interacted directly with and stabilized BOP1 ribosomal biogenesis factor (BOP1). CCAT2 also increased expression of MYC, which activated expression of BOP1. Overexpression of BOP1 in CRC cell lines resulted in chromosomal missegregation errors, and increased colony formation, and invasiveness, whereas BOP1 knockdown reduced viability. BOP1 promoted CIN by increasing the active form of aurora kinase B, which regulates chromosomal segregation. BOP1 was overexpressed in polyp tissues from CCAT2 transgenic mice compared with healthy tissue. CCAT2 lncRNA and BOP1 mRNA or protein were all increased in microsatellite stable tumors (characterized by CIN), but not in tumors with microsatellite instability compared with nontumor tissues. Increased levels of CCAT2 lncRNA and BOP1 mRNA correlated with each other and with shorter survival times of patients. CONCLUSIONS: We found that overexpression of CCAT2 in colon cells promotes CIN and carcinogenesis by stabilizing and inducing expression of BOP1 an activator of aurora kinase B. Strategies to target this pathway might be developed for treatment of patients with microsatellite stable colorectal tumors.


Assuntos
Instabilidade Cromossômica , Neoplasias Colorretais/genética , Neoplasias Experimentais/genética , RNA Longo não Codificante/metabolismo , Proteínas de Ligação a RNA/genética , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Aurora Quinase B/metabolismo , Azoximetano/toxicidade , Carcinogênese/genética , Linhagem Celular Tumoral , Colo/citologia , Colo/patologia , Neoplasias Colorretais/induzido quimicamente , Neoplasias Colorretais/patologia , Análise Citogenética , Dextranos/toxicidade , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Mucosa Intestinal/citologia , Mucosa Intestinal/patologia , Masculino , Camundongos , Camundongos Transgênicos , Neoplasias Experimentais/induzido quimicamente , Neoplasias Experimentais/patologia , Organoides , Cultura Primária de Células , Proteínas Proto-Oncogênicas c-myc/metabolismo , RNA Longo não Codificante/genética , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais/genética
2.
Genome Res ; 28(4): 432-447, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29567676

RESUMO

The cancer-risk-associated rs6983267 single nucleotide polymorphism (SNP) and the accompanying long noncoding RNA CCAT2 in the highly amplified 8q24.21 region have been implicated in cancer predisposition, although causality has not been established. Here, using allele-specific CCAT2 transgenic mice, we demonstrate that CCAT2 overexpression leads to spontaneous myeloid malignancies. We further identified that CCAT2 is overexpressed in bone marrow and peripheral blood of myelodysplastic/myeloproliferative neoplasms (MDS/MPN) patients. CCAT2 induces global deregulation of gene expression by down-regulating EZH2 in vitro and in vivo in an allele-specific manner. We also identified a novel non-APOBEC, non-ADAR, RNA editing at the SNP locus in MDS/MPN patients and CCAT2-transgenic mice. The RNA transcribed from the SNP locus in malignant hematopoietic cells have different allelic composition from the corresponding genomic DNA, a phenomenon rarely observed in normal cells. Our findings provide fundamental insights into the functional role of rs6983267 SNP and CCAT2 in myeloid malignancies.


Assuntos
Proliferação de Células/genética , Doenças Mieloproliferativas-Mielodisplásicas/genética , RNA Longo não Codificante/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Pessoa de Meia-Idade , Doenças Mieloproliferativas-Mielodisplásicas/patologia , Polimorfismo de Nucleotídeo Único/genética , Edição de RNA/genética
3.
J Cell Physiol ; 226(7): 1868-78, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21506117

RESUMO

5-Fluorouracil (5-FU) is a classic chemotherapeutic drug that has been widely used for breast cancer treatment. Although aberrant expression of protein-coding genes was observed after 5-FU treatment, the regulatory mechanism remains poorly understood. MicroRNAs (miRNAs) are a newly identified class of small regulatory RNAs which play an important role in gene regulation at the post-transcriptional levels. Recent evidence suggests an important role of miRNAs in initiation, progression, and metastasis of human cancers. In this study, using a combined advanced microarray and quantitative real-time PCR (qRT-PCR) technology, we show that 5-FU significantly alters the global expression profile of miRNAs in vitro. After 48 h of treatment with a low dose (0.01 µM), 42 miRNAs were differentially expressed in MCF-7 breast cancer cell line. Of these, 23 miRNAs were up-regulated with up to 4.59-fold changes, while 19 were down-regulated with up to 1.89-fold changes. A majority of these miRNAs are associated with cancer development, progression, and metastasis. Target prediction and GO analysis suggest that these differentially expressed miRNAs potentially target many oncogenes, tumor suppressor genes and genes related to programmed cell death, activation of immune response, and cellular catabolic processes.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Neoplasias da Mama/genética , Fluoruracila/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , MicroRNAs/metabolismo , Neoplasias da Mama/imunologia , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Feminino , Perfilação da Expressão Gênica/métodos , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo
4.
Sci Rep ; 8(1): 13106, 2018 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-30166612

RESUMO

The pervasive role of microRNAs (miRNAs) in cancer pathobiology drives the introduction of new drug development approaches such as miRNA inhibition. In order to advance miRNA-therapeutics, meticulous screening strategies addressing specific tumor targets are needed. Small molecule inhibitors represent an attractive goal for these strategies. In this study, we devised a strategy to screen for small molecule inhibitors that specifically inhibit, directly or indirectly, miR-10b (SMIRs) which is overexpressed in metastatic tumors. We found that the multi-tyrosine kinase inhibitor linifanib could significantly inhibit miR-10b and reverse its oncogenic function in breast cancer and liver cancer both in vitro and in vivo. In addition, we showed that the efficacy of linifanib to inhibit tyrosine kinases was reduced by high miR-10b levels. When the level of miR-10b is high, it can "hijack" the linifanib and reduce its kinase inhibitory effects in cancer resulting in reduced anti-tumor efficacy. In conclusion, our study describes an effective strategy to screen for small molecule inhibitors of miRNAs. We further propose that miR-10b expression levels, due to the newly described "hijacking" effect, may be used as a biomarker to select patients for linifanib treatment.


Assuntos
Neoplasias da Mama , Resistencia a Medicamentos Antineoplásicos , Indazóis/farmacologia , Neoplasias Hepáticas , MicroRNAs/metabolismo , Compostos de Fenilureia/farmacologia , RNA Neoplásico/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Feminino , Células Hep G2 , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Células MCF-7 , Masculino , Metástase Neoplásica
5.
Genome Biol ; 18(1): 98, 2017 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-28535802

RESUMO

BACKGROUND: Non-coding RNAs have been drawing increasing attention in recent years as functional data suggest that they play important roles in key cellular processes. N-BLR is a primate-specific long non-coding RNA that modulates the epithelial-to-mesenchymal transition, facilitates cell migration, and increases colorectal cancer invasion. RESULTS: We performed multivariate analyses of data from two independent cohorts of colorectal cancer patients and show that the abundance of N-BLR is associated with tumor stage, invasion potential, and overall patient survival. Through in vitro and in vivo experiments we found that N-BLR facilitates migration primarily via crosstalk with E-cadherin and ZEB1. We showed that this crosstalk is mediated by a pyknon, a short ~20 nucleotide-long DNA motif contained in the N-BLR transcript and is targeted by members of the miR-200 family. In light of these findings, we used a microarray to investigate the expression patterns of other pyknon-containing genomic loci. We found multiple such loci that are differentially transcribed between healthy and diseased tissues in colorectal cancer and chronic lymphocytic leukemia. Moreover, we identified several new loci whose expression correlates with the colorectal cancer patients' overall survival. CONCLUSIONS: The primate-specific N-BLR is a novel molecular contributor to the complex mechanisms that underlie metastasis in colorectal cancer and a potential novel biomarker for this disease. The presence of a functional pyknon within N-BLR and the related finding that many more pyknon-containing genomic loci in the human genome exhibit tissue-specific and disease-specific expression suggests the possibility of an alternative class of biomarkers and therapeutic targets that are primate-specific.


Assuntos
Neoplasias Colorretais/genética , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Leucemia Linfocítica Crônica de Células B/genética , RNA Longo não Codificante/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Caderinas/genética , Caderinas/metabolismo , Movimento Celular , Proliferação de Células , Estudos de Coortes , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Feminino , Loci Gênicos , Células HCT116 , Humanos , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucemia Linfocítica Crônica de Células B/mortalidade , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , MicroRNAs/genética , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Motivos de Nucleotídeos , RNA Longo não Codificante/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Análise de Sobrevida , Transcrição Gênica , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo
6.
EBioMedicine ; 12: 34-42, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27720213

RESUMO

MicroRNAs (miRNAs) are an evolutionarily conserved class of small, regulatory non-coding RNAs that negatively regulate protein coding gene and other non-coding transcripts expression. miRNAs have been established as master regulators of cellular processes, and they play a vital role in tumor initiation, progression and metastasis. Further, widespread deregulation of microRNAs have been reported in several cancers, with several microRNAs playing oncogenic and tumor suppressive roles. Based on these, miRNAs have emerged as promising therapeutic tools for cancer management. In this review, we have focused on the roles of miRNAs in tumorigenesis, the miRNA-based therapeutic strategies currently being evaluated for use in cancer, and the advantages and current challenges to their use in the clinic.


Assuntos
Terapia Genética , MicroRNAs/genética , MicroRNAs/uso terapêutico , Neoplasias/genética , Neoplasias/terapia , Animais , Ensaios Clínicos como Assunto , Avaliação Pré-Clínica de Medicamentos , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Terapia Genética/efeitos adversos , Terapia Genética/métodos , Humanos , Imunomodulação/genética , Neoplasias/imunologia , Neoplasias/patologia , Interferência de RNA , Resultado do Tratamento , Microambiente Tumoral/genética , Microambiente Tumoral/imunologia
7.
Wiley Interdiscip Rev RNA ; 5(4): 537-48, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24687772

RESUMO

MicroRNAs (miRNAs) are evolutionarily conserved, small, regulatory RNAs that negatively regulate gene expression. Extensive research in the last decade has implicated miRNAs as master regulators of cellular processes with essential role in cancer initiation, progression, and metastasis, making them promising therapeutic tools for cancer management. In this article, we will briefly review the structure, biogenesis, functions, and mechanism of action of these miRNAs, followed by a detailed analysis of the therapeutic potential of these miRNAs. We will focus on the strategies presently used for miRNA therapy; discuss their use and drawbacks; and the challenges and future directions for the development of miRNA-based therapy for human cancers.


Assuntos
MicroRNAs/antagonistas & inibidores , Terapia de Alvo Molecular , Neoplasias/genética , Neoplasias/terapia , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Neoplasias/metabolismo
8.
Nucleic Acid Ther ; 23(1): 2-8, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23051203

RESUMO

The recent discovery of functional cell-free circulating microRNAs (miRNAs) in human body fluids has opened new avenues for the application of non-coding RNAs (ncRNAs) as noninvasive, specific and sensitive biomarkers for cancers and other human diseases. In this review, we explore the concept of circulating miRNAs as hormones, and discuss their potential functions in cellular communication and transferring of signals. We also provide a brief overview of their identification, processing, and potential functions and applications in human diseases.


Assuntos
Hormônios/metabolismo , RNA não Traduzido/metabolismo , Biomarcadores/metabolismo , Líquidos Corporais/metabolismo , Comunicação Celular , Hormônios/genética , Humanos , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , MicroRNAs/metabolismo , Modelos Biológicos , Neoplasias/genética , Neoplasias/metabolismo , RNA Neoplásico/genética , RNA Neoplásico/metabolismo , RNA não Traduzido/genética , Transdução de Sinais
9.
Cancer Discov ; 3(11): 1302-15, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24002999

RESUMO

UNLABELLED: Development of improved RNA interference-based strategies is of utmost clinical importance. Although siRNA-mediated silencing of EphA2, an ovarian cancer oncogene, results in reduction of tumor growth, we present evidence that additional inhibition of EphA2 by a microRNA (miRNA) further "boosts" its antitumor effects. We identified miR-520d-3p as a tumor suppressor upstream of EphA2, whose expression correlated with favorable outcomes in two independent patient cohorts comprising 647 patients. Restoration of miR-520d-3p prominently decreased EphA2 protein levels, and suppressed tumor growth and migration/invasion both in vitro and in vivo. Dual inhibition of EphA2 in vivo using 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPC) nanoliposomes loaded with miR-520d-3p and EphA2 siRNA showed synergistic antitumor efficiency and greater therapeutic efficacy than either monotherapy alone. This synergy is at least in part due to miR-520d-3p targeting EphB2, another Eph receptor. Our data emphasize the feasibility of combined miRNA-siRNA therapy, and will have broad implications for innovative gene silencing therapies for cancer and other diseases. SIGNIFICANCE: This study addresses a new concept of RNA inhibition therapy by combining miRNA and siRNA in nanoliposomal particles to target oncogenic pathways altered in ovarian cancer. Combined targeting of the Eph pathway using EphA2-targeting siRNA and the tumor suppressor miR-520d-3p exhibits remarkable therapeutic synergy and enhanced tumor suppression in vitro and in vivo compared with either monotherapy alone.


Assuntos
Antineoplásicos/uso terapêutico , MicroRNAs/uso terapêutico , Neoplasias Ovarianas/tratamento farmacológico , RNA Interferente Pequeno/uso terapêutico , Receptor EphA2/antagonistas & inibidores , Receptor EphB2/antagonistas & inibidores , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Estudos de Coortes , Quimioterapia Combinada , Feminino , Inativação Gênica , Humanos , Camundongos , Camundongos Nus , MicroRNAs/farmacologia , Terapia de Alvo Molecular , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Fosfatidilcolinas/farmacologia , RNA Interferente Pequeno/farmacologia , Receptor EphA2/genética , Receptor EphA2/metabolismo , Receptor EphB2/genética , Receptor EphB2/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Nat Commun ; 4: 2427, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24018975

RESUMO

The miR-200 family is well known to inhibit the epithelial-mesenchymal transition, suggesting it may therapeutically inhibit metastatic biology. However, conflicting reports regarding the role of miR-200 in suppressing or promoting metastasis in different cancer types have left unanswered questions. Here we demonstrate a difference in clinical outcome based on miR-200's role in blocking tumour angiogenesis. We demonstrate that miR-200 inhibits angiogenesis through direct and indirect mechanisms by targeting interleukin-8 and CXCL1 secreted by the tumour endothelial and cancer cells. Using several experimental models, we demonstrate the therapeutic potential of miR-200 delivery in ovarian, lung, renal and basal-like breast cancers by inhibiting angiogenesis. Delivery of miR-200 members into the tumour endothelium resulted in marked reductions in metastasis and angiogenesis, and induced vascular normalization. The role of miR-200 in blocking cancer angiogenesis in a cancer-dependent context defines its utility as a potential therapeutic agent.


Assuntos
MicroRNAs/metabolismo , Neoplasias/irrigação sanguínea , Neoplasias/genética , Neovascularização Patológica/genética , Inibidores da Angiogênese/farmacologia , Inibidores da Angiogênese/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Movimento Celular/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Redes Reguladoras de Genes/efeitos dos fármacos , Humanos , Interleucina-8/genética , Interleucina-8/metabolismo , Neoplasias Pulmonares/secundário , MicroRNAs/genética , Modelos Biológicos , Nanopartículas/administração & dosagem , Metástase Neoplásica , Neoplasias/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Oligonucleotídeos/farmacologia , Oligonucleotídeos/uso terapêutico , Pericitos/efeitos dos fármacos , Pericitos/patologia , Resultado do Tratamento
11.
Genome Med ; 3(8): 56, 2011 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-21888691

RESUMO

MicroRNAs (miRNAs) are crucial in the initiation and progression of tumors. A recent study has reported that the miRNAs miR-221 and miR-222 are involved in the promotion of an aggressive basal-like phenotype in breast cancer, functioning downstream of the RAS pathway and triggering epithelial-to-mesenchymal transition. These new insights into the roles of miR-221/222 in breast cancer metastasis, drug resistance and RAS pathways could potentially have applications in medical practice.

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