Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
1.
Mol Ther ; 32(6): 1956-1969, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38627967

RESUMO

Epithelial-to-mesenchymal transition (EMT) that endows cancer cells with increased invasive and migratory capacity enables cancer dissemination and metastasis. This process is tightly associated with metabolic reprogramming acquired for rewiring cell status and signaling pathways for survival in dietary insufficiency conditions. However, it remains largely unclear how transcription factor (TF)-mediated transcriptional programs are modulated during the EMT process. Here, we reveal that depletion of a key epithelial TF, ELF3 (E74-like factor-3), triggers a transforming growth factor ß (TGF-ß) signaling activation-like mesenchymal transcriptomic profile and metastatic features linked to the aminoacyl-tRNA biogenesis pathway. Moreover, the transcriptome alterations elicited by ELF3 depletion perfectly resemble an ATF4-dependent weak response to amino acid starvation. Intriguingly, we observe an exclusive enrichment of ELF3 and ATF4 in epithelial and TGF-ß-induced or ELF3-depletion-elicited mesenchymal enhancers, respectively, with rare co-binding on altered enhancers. We also find that the upregulation of aminoacyl-tRNA synthetases and some mesenchymal genes upon amino acid deprivation is diminished in ATF4-depleted cells. In sum, the loss of ELF3 binding on epithelial enhancers and the gain of ATF4 binding on the enhancers of mesenchymal factors and amino acid deprivation responsive genes facilitate the loss of epithelial cell features and the gain of TGF-ß-signaling-associated mesenchymal signatures, which further promote lung cancer cell metastasis.


Assuntos
Fator 4 Ativador da Transcrição , Aminoácidos , Proteínas de Ligação a DNA , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Fatores de Transcrição , Fator de Crescimento Transformador beta , Transição Epitelial-Mesenquimal/genética , Fator 4 Ativador da Transcrição/metabolismo , Fator 4 Ativador da Transcrição/genética , Humanos , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Aminoácidos/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/genética , Linhagem Celular Tumoral , Transdução de Sinais , Proteínas Proto-Oncogênicas c-ets/metabolismo , Proteínas Proto-Oncogênicas c-ets/genética , Transcriptoma , Animais
2.
Cancer Gene Ther ; 31(4): 612-626, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38291129

RESUMO

Dysregulation of histone acetylation is widely implicated in tumorigenesis, yet its specific roles in the progression and metastasis of esophageal squamous cell carcinoma (ESCC) remain unclear. Here, we profiled the genome-wide landscapes of H3K9ac for paired adjacent normal (Nor), primary ESCC (EC) and metastatic lymph node (LNC) esophageal tissues from three ESCC patients. Compared to H3K27ac, we identified a distinct epigenetic reprogramming specific to H3K9ac in EC and LNC samples relative to Nor samples. This H3K9ac-related reprogramming contributed to the transcriptomic aberration of targeting genes, which were functionally associated with tumorigenesis and metastasis. Notably, genes with gained H3K9ac signals in both primary and metastatic lymph node samples (common-gained gene) were significantly enriched in oncogenes. Single-cell RNA-seq analysis further revealed that the corresponding top 15 common-gained genes preferred to be enriched in mesenchymal cells with high metastatic potential. Additionally, in vitro experiment demonstrated that the removal of H3K9ac from the common-gained gene MSI1 significantly downregulated its transcription, resulting in deficiencies in ESCC cell proliferation and migration. Together, our findings revealed the distinct characteristics of H3K9ac in esophageal squamous cell carcinogenesis and metastasis, and highlighted the potential therapeutic avenue for intervening ESCC through epigenetic modulation via H3K9ac.


Assuntos
Carcinoma de Células Escamosas , Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Humanos , Carcinoma de Células Escamosas do Esôfago/genética , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Histonas/genética , Lisina/uso terapêutico , Neoplasias Esofágicas/patologia , Acetilação , Proliferação de Células/genética , Carcinogênese , Proteínas do Tecido Nervoso , Proteínas de Ligação a RNA
3.
Comput Struct Biotechnol J ; 21: 856-868, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36698964

RESUMO

Base editing tools enable precise genome modifications, disease modeling, and promising gene therapy. However, many human genetic diseases are elicited by multi-nucleotide variants (MNVs) with heterogeneous substitutions at the same genomic locus. Based on the adenine and cytosine base editors, dual base editors that can catalyze concurrent C-to-T and A-to-G editing have been developed, while simultaneous C&G-to-T&A and A&T-to-G&C conversions on the same allele have not been achieved at the desirable site. Here we propose a strategy of combining base editors with dual guide RNAs (gRNAs) that target two overlapped neighboring loci on the opposite strands, which can induce simultaneous C&G-to-T&A and A&T-to-G&C conversions within their overlapping targeting windows. Moreover, one of the paired gRNAs is mutated to perfectly match another gRNA-edited sequence, efficiently facilitating concurrent base conversions on the same allele. To further expand the targeting scopes, PAMless SpRY Cas9-mediated base editors are combined with our optimized dual gRNAs system to induce expected concurrent base editing and to install neighboring pathogenic MNVs in TP53 in cancer cells. In addition, more complex mutation types can be achieved by integrating dual base editors and our dual gRNAs strategy. Thus, we establish a general strategy to efficiently induce MNVs in human genome, helping to dissect the functions of pathogenic MNVs with multifarious types.

4.
Adv Sci (Weinh) ; 9(30): e2200717, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36045417

RESUMO

Selective inhibition of targeted protein kinases is an effective therapeutic approach for treatment of human malignancies, which interferes phosphorylation of cellular substrates. However, a drug-imposed selection creates pressures for tumor cells to acquire chemoresistance-conferring mutations or activating alternative pathways, which can bypass the inhibitory effects of kinase inhibitors. Thus, identifying downstream phospho-substrates conferring drug resistance is of great importance for developing poly-pharmacological and targeted therapies. To identify functional phosphorylation sites involved in 5-fluorouracil (5-FU) resistance during its treatment of colorectal cancer cells, CRISPR-mediated cytosine base editor (CBE) and adenine base editor (ABE) are utilized for functional screens by mutating phosphorylated amino acids with two libraries specifically targeting 7779 and 10 149 phosphorylation sites. Among the top enriched gRNAs-induced gain-of-function mutants, the target genes are involved in cell cycle and post-translational covalent modifications. Moreover, several substrates of RSK2 and PAK4 kinases are discovered as main effectors in responding to 5-FU chemotherapy, and combinational treatment of colorectal cancer cells with 5-FU and RSK2 inhibitor or PAK4 inhibitor can largely inhibit cell growth and enhance cell apoptosis through a RSK2/TP53BP1/γ-H2AX phosphorylation signaling axis. It is proposed that this screen approach can be used for functional phosphoproteomics in chemotherapy of various human diseases.


Assuntos
Neoplasias Colorretais , Resistencia a Medicamentos Antineoplásicos , Humanos , Resistencia a Medicamentos Antineoplásicos/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Fluoruracila/farmacologia , Fluoruracila/uso terapêutico , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Proteínas Quinases/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Adenina/farmacologia , Adenina/uso terapêutico , Aminoácidos/genética , Aminoácidos/farmacologia , Aminoácidos/uso terapêutico , Citosina/farmacologia , Citosina/uso terapêutico , Quinases Ativadas por p21/genética , Quinases Ativadas por p21/metabolismo , Quinases Ativadas por p21/farmacologia
6.
NPJ Genom Med ; 6(1): 65, 2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34381055

RESUMO

Trimethylation of histone H3 lysine 27 trimethylation (H3K27me3) may be recruited by repressive Polycomb complexes to mediate gene silencing, which is critical for maintaining embryonic stem cell pluripotency and differentiation. However, the roles of aberrant H3K27me3 patterns in tumorigenesis are not fully understood. Here, we discovered that grand silencer domains (breadth > 50 kb) for H3K27me3 were significantly associated with epithelial cell differentiation and exhibited high gene essentiality and conservation in human esophageal epithelial cells. These grand H3K27me3 domains exhibited high modification signals involved in gene silencing, and preferentially occupied the entirety of topologically associating domains and interact with each other. We found that widespread loss of the grand H3K27me3 domains in of esophageal squamous cell carcinomas (ESCCs) were enriched in genes involved in epithelium and endothelium differentiation, which were significantly associated with overexpression with increase of active modifications of H3K4me3, H3K4me1, and H3K27ac marks, as well as DNA hypermethylation in the gene bodies. A total of 208 activated genes with loss of grand H3K27me3 domains in ESCC were identified, where the higher expression and mutation of T-box transcription factor 20 (TBX20) were associated with worse patients' outcomes. Our results showed that knockdown of TBX20 may have led to a striking defect in esophageal cancer cell growth and carcinogenesis-related pathway, including cell cycle and homologous recombination. Together, our results reveal that loss of grand H3K27me3 domains represent a catalog of remarkable activating regulators involved in carcinogenesis.

7.
Cell Prolif ; 54(8): e13096, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34240779

RESUMO

OBJECTIVES: PKM1 and PKM2, which are generated from the alternative splicing of PKM gene, play important roles in tumourigenesis and embryonic development as rate-limiting enzymes in glycolytic pathway. However, because of the lack of appropriate techniques, the specific functions of the 2 PKM splicing isoforms have not been clarified endogenously yet. MATERIALS AND METHODS: In this study, we used CRISPR-based base editors to perturbate the endogenous alternative splicing of PKM by introducing mutations into the splicing junction sites in HCT116 cells and zebrafish embryos. Sanger sequencing, agarose gel electrophoresis and targeted deep sequencing assays were utilized for identifying mutation efficiencies and detecting PKM1/2 splicing isoforms. Cell proliferation assays and RNA-seq analysis were performed to describe the effects of perturbation of PKM1/2 splicing in tumour cell growth and zebrafish embryo development. RESULTS: The splicing sites of PKM, a 5' donor site of GT and a 3' acceptor site of AG, were efficiently mutated by cytosine base editor (CBE; BE4max) and adenine base editor (ABE; ABEmax-NG) with guide RNAs (gRNAs) targeting the splicing sites flanking exons 9 and 10 in HCT116 cells and/or zebrafish embryos. The mutations of the 5' donor sites of GT flanking exons 9 or 10 into GC resulted in specific loss of PKM1 or PKM2 expression as well as the increase in PKM2 or PKM1 respectively. Specific loss of PKM1 promoted cell proliferation of HCT116 cells and upregulated the expression of cell cycle regulators related to DNA replication and cell cycle phase transition. In contrast, specific loss of PKM2 suppressed cell growth of HCT116 cells and resulted in growth retardation of zebrafish. Meanwhile, we found that mutation of PKM1/2 splicing sites also perturbated the expression of non-canonical PKM isoforms and produced some novel splicing isoforms. CONCLUSIONS: This work proved that CRISPR-based base editing strategy can be used to disrupt the endogenous alternative splicing of genes of interest to study the function of specific splicing isoforms in vitro and in vivo. It also reminded us to notice some novel or undesirable splicing isoforms by targeting the splicing junction sites using base editors. In sum, we establish a platform to perturbate endogenous RNA splicing for functional investigation or genetic correction of abnormal splicing events in human diseases.


Assuntos
Edição de Genes , Piruvato Quinase/metabolismo , Processamento Alternativo , Animais , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proliferação de Células , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Regulação para Baixo , Éxons , Feminino , Células HCT116 , Humanos , Mutagênese , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Piruvato Quinase/genética , Regulação para Cima , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
8.
Nat Commun ; 12(1): 4457, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34294701

RESUMO

The role of cis-elements and their aberrations remains unclear in esophageal squamous cell carcinoma (ESCC, further abbreviated EC). Here we survey 28 H3K27ac-marked active enhancer profiles and 50 transcriptomes in primary EC, metastatic lymph node cancer (LNC), and adjacent normal (Nor) esophageal tissues. Thousands of gained or lost enhancers and hundreds of altered putative super-enhancers are identified in EC and LNC samples respectively relative to Nor, with a large number of common gained or lost enhancers. Moreover, these differential enhancers contribute to the transcriptomic aberrations in ECs and LNCs. We also reveal putative driver onco-transcription factors, depletion of which diminishes cell proliferation and migration. The administration of chemical inhibitors to suppress the predicted targets of gained super-enhances reveals HSP90AA1 and PDE4B as potential therapeutic targets for ESCC. Thus, our epigenomic profiling reveals a compendium of reprogrammed cis-regulatory elements during ESCC carcinogenesis and metastasis for uncovering promising targets for cancer treatment.


Assuntos
Elementos Facilitadores Genéticos , Neoplasias Esofágicas/genética , Carcinoma de Células Escamosas do Esôfago/genética , Idoso , Carcinogênese/genética , Linhagem Celular Tumoral , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/secundário , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Ontologia Genética , Código das Histonas/genética , Humanos , Metástase Linfática/genética , Masculino , Pessoa de Meia-Idade , Oncogenes , Fatores de Transcrição/genética
9.
Nat Commun ; 12(1): 2287, 2021 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-33863894

RESUMO

Both adenine base editors (ABEs) and cytosine base editors (CBEs) have been recently revealed to induce transcriptome-wide RNA off-target editing in a guide RNA-independent manner. Here we construct a reporter system containing E.coli Hokb gene with a tRNA-like motif for robust detection of RNA editing activities as the optimized ABE, ABEmax, induces highly efficient A-to-I (inosine) editing within an E.coli tRNA-like structure. Then, we design mutations to disrupt the potential interaction between TadA and tRNAs in structure-guided principles and find that Arginine 153 (R153) within TadA is essential for deaminating RNAs with core tRNA-like structures. Two ABEmax or mini ABEmax variants (TadA* fused with Cas9n) with deletion of R153 within TadA and/or TadA* (named as del153/del153* and mini del153) are successfully engineered, showing minimized RNA off-targeting, but comparable DNA on-targeting activities. Moreover, R153 deletion in recently reported ABE8e or ABE8s can also largely reduce their RNA off-targeting activities. Taken together, we develop a strategy to generate engineered ABEs (eABEs) with minimized RNA off-targeting activities.


Assuntos
Adenosina Desaminase/genética , Proteína 9 Associada à CRISPR/genética , DNA/genética , Proteínas de Escherichia coli/genética , Edição de Genes/métodos , Adenina/metabolismo , Adenosina Desaminase/metabolismo , Toxinas Bacterianas/genética , Proteína 9 Associada à CRISPR/metabolismo , Linhagem Celular Tumoral , Citosina/metabolismo , DNA/metabolismo , Proteínas de Escherichia coli/metabolismo , Genes Reporter , Células HEK293 , Humanos , Inosina/genética , Inosina/metabolismo , Engenharia de Proteínas , Edição de RNA/genética , RNA de Transferência/genética , RNA de Transferência/metabolismo , RNA-Seq , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo
10.
Mol Ther ; 28(9): 2083-2095, 2020 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-32526202

RESUMO

Transcription growth factor ß (TGF-ß) signaling-triggered epithelial-to-mesenchymal transition (EMT) process is associated with tumor stemness, metastasis, and chemotherapy resistance. However, the epigenomic basis for TGF-ß-induced EMT remains largely unknown. Here we reveal that HDAC1-mediated global histone deacetylation and the gain of specific histone H3 lysine 27 acetylation (H3K27ac)-marked enhancers are essential for the TGF-ß-induced EMT process. Enhancers gained upon TGF-ß treatment are linked to gene activation of EMT markers and cancer metastasis. Notably, dynamic enhancer gain or loss mainly occurs within pre-existing topologically associated domains (TADs) in epithelial cells, with minimal three-dimensional (3D) genome architecture reorganization. Through motif enrichment analysis of enhancers that are lost or gained upon TGF-ß stimulation, we identify FOXA2 as a key factor to activate epithelial-specific enhancer activity, and we also find that TEAD4 forms a complex with SMAD2/3 to mediate TGF-ß signaling-triggered mesenchymal enhancer reprogramming. Together, our results implicate that key transcription-factor (TF)-mediated enhancer reprogramming modulates the developmental transition in TGF-ß signaling-associated cancer metastasis.


Assuntos
Reprogramação Celular/efeitos dos fármacos , Elementos Facilitadores Genéticos/efeitos dos fármacos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Fator de Crescimento Transformador beta/farmacologia , Células A549 , Animais , Carcinogênese/efeitos dos fármacos , Carcinogênese/genética , Proteínas de Ligação a DNA/metabolismo , Células HEK293 , Fator 3-beta Nuclear de Hepatócito/metabolismo , Hepatócitos/metabolismo , Histona Desacetilase 1/metabolismo , Histonas/metabolismo , Humanos , Camundongos , Proteínas Musculares/metabolismo , Metástase Neoplásica , Proteína Smad2/metabolismo , Proteína Smad3/metabolismo , Fatores de Transcrição de Domínio TEA , Fatores de Transcrição/metabolismo , Ativação Transcricional/efeitos dos fármacos , Fator de Crescimento Transformador beta/metabolismo
11.
Nat Commun ; 10(1): 3733, 2019 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-31427575

RESUMO

Hearing loss is the most common sensory disorder. While gene therapy has emerged as a promising treatment of inherited diseases like hearing loss, it is dependent on the identification of gene delivery vectors. Adeno-associated virus (AAV) vector-mediated gene therapy has been approved in the US for treating a rare inherited eye disease but no safe and efficient vectors have been identified that can target the diverse types of inner ear cells. Here, we identify an AAV variant, AAV-inner ear (AAV-ie), for gene delivery in mouse inner ear. Our results show that AAV-ie transduces the cochlear supporting cells (SCs) with high efficiency, representing a vast improvement over conventional AAV serotypes. Furthermore, after AAV-ie-mediated transfer of the Atoh1 gene, we find that many SCs trans-differentiated into new HCs. Our results suggest that AAV-ie is a useful tool for the cochlear gene therapy and for investigating the mechanism of HC regeneration.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Dependovirus/genética , Terapia Genética/métodos , Células Ciliadas Auditivas Internas/citologia , Perda Auditiva/genética , Perda Auditiva/terapia , Animais , Células Cultivadas , Feminino , Técnicas de Transferência de Genes , Vetores Genéticos/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL
12.
Cancer Lett ; 451: 110-121, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30851421

RESUMO

Prostate cancer (PCa) is the most common solid organ malignancy among men, outnumbering both lung and colorectal cancer, and it is the second leading cause of male tumor-related death in the United States due to high metastasis. Recently, leukemia inhibitory factor receptor (LIFR) has been found to play roles in multiple types of cancer. However, the roles of LIFR in the progression of PCa remain to be revealed. In this study, we found that LIFR plays an oncogenic role in PCa. The phosphorylation of LIFR at S1044 contributes to subsequent activation of the AKT pathway, inducing the expression of a series of proliferation and metastatic genes. Additionally, LIFR-S1044 is phosphorylated by ERK2 but not ERK1. The signal intensity of pLIFR-S1044 and pAKT S473 in PCa tissue displays a tight positive correlation. The ERK2/LIFR/AKT axis modulates PCa progression and offers a promising therapeutic and diagnostic target for PCa.


Assuntos
Subunidade alfa de Receptor de Fator Inibidor de Leucemia/metabolismo , Neoplasias da Próstata/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Xenoenxertos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Fosforilação
13.
Cell Rep ; 26(2): 302-312.e4, 2019 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-30625312

RESUMO

The coactivator-associated arginine methyltransferase CARM1 catalyzes the methylation of histone H3 arginine 17/26 (H3R17/26me) and non-histone proteins at arginine residues to regulate gene transactivation through profiling or Carm1 overexpression assays. However, the direct relationship between H3R17/26me and its causal role in mouse embryo development remains largely unclear. Here, we use rAPOBEC1-XTEN-Cas9n-UGI (BE3) to efficiently introduce a point mutation (R17H) at multiple Hist1/2H3 loci and a premature-stop codon into the catalytic domain of CARM1 in mouse embryos, resulting in remarkable downregulation of H3R17me levels and developmental defects in pre-implantation and fetal embryos. Transcriptomic analysis reveals that Yap1 and cell cycle signaling pathways are dysregulated in Carm1 truncation and H3R17H substitution embryos, and Yap1 overexpression could rescue the base-editing-elicited defects. Our data establish the direct regulatory relationship between CARM1-mediated H3R17me and early mouse embryo development and demonstrate that Yap1 acts downstream of CARM1-mediated H3R17me to regulate the mouse embryo development.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Ciclo Celular/metabolismo , Desenvolvimento Embrionário , Regulação da Expressão Gênica no Desenvolvimento , Histonas/metabolismo , Transdução de Sinais , Animais , Domínio Catalítico , Ciclo Celular , Linhagem Celular Tumoral , Código das Histonas , Histonas/química , Histonas/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Mutação de Sentido Incorreto , Proteína-Arginina N-Metiltransferases/química , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismo , Transcriptoma , Proteínas de Sinalização YAP
14.
Sci Bull (Beijing) ; 64(21): 1592-1600, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36659571

RESUMO

Allele-specific DNA methylation is the most important imprinting marker localized to differentially methylated regions (DMRs), and aberrant genomic imprinted DNA methylation is associated with some human diseases, including Prader-Willi syndrome and cancer. Thus, the development of an effective strategy for the precise editing of allele-specific methylated genes is essential for the functional clarification of imprinting elements and the correction of imprinting disorders in human diseases. To discover a feasible allele-specific genome editing tool based on the CRISPR/Cas system, which is an efficient gene-targeting technique in various organisms, we examined the targeting efficiency of Staphylococcus aureus Cas9 (SaCas9) and Streptococcus pyogenes Cas9 (SpCas9) in response to DNA methylation interference. We found that the targeting efficiency of SaCas9, but not SpCas9, was enhanced by targeted DNA demethylation using the dCas9-Tet1 catalytic domain (CD) but suppressed by targeted DNA methylation using Dnmt3l-Dnmt3a-dCas9. An in vitro cleavage assay further demonstrated that SaCas9 nuclease activity was inhibited by 5-methylcytosine (5mC) in a synthesized CpG-containing context. Further analysis with ChIP-Q-PCR demonstrated that the non-methylated sequence targeting of SaCas9 depends on the binding preference of SaCas9 to non-methylated sequences. Taking advantage of this feature of SaCas9, we have successfully obtained non-methylated allele-biased targeted embryos/mice for two imprinting genes, H19 and Snrpn, with relatively high efficiencies of 28.6% and 47.4%, respectively. These results indicate that the targeting efficiency of SaCas9 was strongly reduced by DNA methylation. By using SaCas9, we successfully achieved allele-specific genome editing of imprinting genes by preferentially targeting non-methylated loci.

15.
J Mol Cell Biol ; 10(3): 216-228, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29481611

RESUMO

Clinical therapies of pluripotent stem cells (PSCs)-based transplantation have been hindered by frequent development of teratomas or tumors in animal models and clinical patients. Therefore, clarifying the mechanism of carcinogenesis in stem cell therapy is of great importance for reducing the risk of tumorigenicity. Here we differentiate Oct4-GFP mouse embryonic stem cells (mESCs) into neural progenitor cells (NPCs) and find that a minority of Oct4+ cells are continuously sustained at Oct4+ state. These cells can be enriched and proliferated in a standard ESC medium. Interestingly, the differentiation potential of these enriched cells is tightly restricted with much higher tumorigenic activity, which are thus defined as differentiation-resistant ESCs (DR-ESCs). Transcriptomic and epigenomic analyses show that DR-ESCs are characterized by primordial germ cell-like gene signatures (Dazl, Rec8, Stra8, Blimp1, etc.) and specific epigenetic patterns distinct from mESCs. Moreover, the DR-ESCs possess germ cell potential to generate Sycp3+ haploid cells and are able to reside in sperm-free spermaduct induced by busulfan. Finally, we find that TGFß signaling is overactivated in DR-ESCs, and inhibition of TGFß signaling eliminates the tumorigenicity of mESC-derived NPCs by inducing the full differentiation of DR-ESCs. These data demonstrate that these TGFß-hyperactivated germ cell-like DR-ESCs are the main contributor for the tumorigenicity of ESCs-derived target cell therapy and that inhibition of TGFß signaling in ESC-derived NPC transplantation could drastically reduce the risk of tumor development.


Assuntos
Carcinogênese/metabolismo , Células-Tronco Embrionárias Murinas/citologia , Células-Tronco Neurais/citologia , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismo , Animais , Carcinogênese/genética , Diferenciação Celular , Linhagem Celular , Epigênese Genética , Camundongos , Células-Tronco Embrionárias Murinas/metabolismo , Células-Tronco Neurais/metabolismo , Transcriptoma
16.
Cell Rep ; 18(4): 933-946, 2017 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-28122243

RESUMO

LIF promotes self-renewal of mouse embryonic stem cells (mESCs), and in its absence, the cells differentiate. LIF binds to the LIF receptor (LIFR) and activates the JAK-STAT3 pathway, but it remains unknown how the receptor complex triggers differentiation or self-renewal. Here, we report that the LIFR cytoplasmic domain contains a self-renewal domain within the juxtamembrane region and a differentiation domain within the C-terminal region. The differentiation domain contains four SPXX repeats that are phosphorylated by MAPK to restrict STAT3 activation; the self-renewal domain is characterized by a 3K motif that is acetylated by p300. In mESCs, acetyl-LIFR undergoes homodimerization, leading to STAT3 hypo- or hyper-activation depending on the presence or absence of gp130. LIFR-activated STAT3 restricts differentiation via cytokine induction. Thus, LIFR acetylation and serine phosphorylation differentially promote stem cell self-renewal and differentiation.


Assuntos
Subunidade alfa de Receptor de Fator Inibidor de Leucemia/metabolismo , Células-Tronco Embrionárias Murinas/metabolismo , Acetilação/efeitos dos fármacos , Motivos de Aminoácidos , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Autorrenovação Celular/efeitos dos fármacos , Receptor gp130 de Citocina/metabolismo , Proteína p300 Associada a E1A/antagonistas & inibidores , Proteína p300 Associada a E1A/genética , Proteína p300 Associada a E1A/metabolismo , Células HEK293 , Histona Desacetilases/química , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Humanos , Ácidos Hidroxâmicos/farmacologia , Fator Inibidor de Leucemia/farmacologia , Subunidade alfa de Receptor de Fator Inibidor de Leucemia/química , Subunidade alfa de Receptor de Fator Inibidor de Leucemia/genética , Camundongos , Camundongos Knockout , Células-Tronco Embrionárias Murinas/citologia , Fosforilação/efeitos dos fármacos , Interferência de RNA , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos
17.
Oncotarget ; 6(42): 44373-87, 2015 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-26517242

RESUMO

DNA methylation is clinically relevant to important tumorigenic mechanisms. This study evaluated the methylation status of candidate genes in cervical neoplasia and determined their diagnostic performance in clinical practice. Cervical cancer and normal cervix tissue was used to select the top 5 discriminating loci among 27 loci in 4 genes (CCNA1, CADM1, DAPK1, JAM3), and one locus of JAM3 (region M4) was identified and confirmed with 267 and 224 cervical scrapings from 2 independent colposcopy referral studies. For patients with atypical squamous cells of unknown significance and those with low-grade squamous intraepithelial lesion, with JAM3-M4 compared to a triage marker of hrHPV testing, the specificity for cervical intraepithelial neoplasia 3 CIN3 and cancer cases (CIN3+) / no neoplasia and CIN1 (CIN1-) was significantly increased, from 21.88 to 81.82 and 15.38 to 85.18, respectively. The corresponding positive predictive value (PPV) was increased from 26.47 to 57.14 and 18.52 to 63.64, respectively. For hrHPV-positive patients, compared to a triage marker of cytology testing, JAM3-M4 showed increased specificity and PPV, from 30.67 to 87.65 and 38.82 to 82.14, respectively. We assessed whether JAM3-M4 could distinguish productive from transforming CIN2; the coincidence rate of JAM3-M4 and P16 was as high as 60.5%.


Assuntos
Células Escamosas Atípicas do Colo do Útero , Biomarcadores Tumorais/genética , Moléculas de Adesão Celular/genética , Metilação de DNA , Infecções por Papillomavirus/genética , Lesões Pré-Cancerosas/genética , Lesões Intraepiteliais Escamosas Cervicais/genética , Displasia do Colo do Útero/genética , Neoplasias do Colo do Útero/genética , Adulto , Área Sob a Curva , Células Escamosas Atípicas do Colo do Útero/química , Células Escamosas Atípicas do Colo do Útero/patologia , Células Escamosas Atípicas do Colo do Útero/virologia , Biomarcadores Tumorais/análise , Inibidor p16 de Quinase Dependente de Ciclina/análise , Diagnóstico Diferencial , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Reação em Cadeia da Polimerase , Lesões Pré-Cancerosas/química , Lesões Pré-Cancerosas/patologia , Lesões Pré-Cancerosas/virologia , Valor Preditivo dos Testes , Curva ROC , Reprodutibilidade dos Testes , Lesões Intraepiteliais Escamosas Cervicais/metabolismo , Lesões Intraepiteliais Escamosas Cervicais/patologia , Lesões Intraepiteliais Escamosas Cervicais/virologia , Neoplasias do Colo do Útero/química , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia , Esfregaço Vaginal , Displasia do Colo do Útero/química , Displasia do Colo do Útero/patologia , Displasia do Colo do Útero/virologia
18.
Asian Pac J Cancer Prev ; 16(5): 1907-12, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25773843

RESUMO

PURPOSE: The study was designed to: (1) investigate the prevalence of high-risk human papillomavirus (HR- HPV) infection and cervical neoplasia; and (2) evaluate clinical performance of visual inspection with acetic acid/ Lugol's iodine (VIA /VILI), Pap smear, high-risk human papillomavirus (HR-HPV) DNA test for detecting cervical intraepithelial neoplasia grade 2 or worse (CIN2+) and (3) explore appropriate screening approach in rural areas of Shandong Province. MATERIALS AND METHODS: A total of 3,763 eligible women from Yiyuan County in Yimeng mountainous areas of rural Shandong, China, were enrolled and underwent Pap smear, HR-HPV DNA testing by Hybrid Capture 2 (HC2), and VIA /VILI tests. Women positive in any test were referred to colposcopy and biopsy as indicated. RESULTS: The prevalence of HR-HPV infection among all enrolled women was 11.1% and that in healthy women was 9.9%. In total 33 cases of CIN1, 16 cases of CIN2, 6 cases of CIN3 but none of cervical cancer were detected and the crude prevalence of CIN2+ was 0.58%. For detecting CIN2+, the sensitivity of HR-HPV DNA testing, VIA/VILI, Pap smear was 90.9%, 77.3%, 81.8%, respectively. Pap smear had the best specificity of 98.2%, followed by HR-HPV DNA testing with specificity of 89.4%, VIA/VILI had the lowest specificity of 81.2%. Colposcopy referral rate of HR-HPV DNA testing, VIA/VILI, Pap smear was 11.1%, 18.5%, 2.3%, respectively. CONCLUSIONS: Our results suggest that HR-HPV DNA testing alone might be appropriate for primary cervical cancer screening in rural low-resource areas of Shandong Province, China.


Assuntos
Detecção Precoce de Câncer/métodos , Testes de DNA para Papilomavírus Humano/métodos , Programas de Rastreamento/métodos , Displasia do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/diagnóstico , Ácido Acético , Adulto , Alphapapillomavirus/genética , China/epidemiologia , DNA Viral/isolamento & purificação , Feminino , Humanos , Iodetos , Pessoa de Meia-Idade , Teste de Papanicolaou/métodos , Infecções por Papillomavirus/epidemiologia , Saúde da População Rural , População Rural , Esfregaço Vaginal/métodos
19.
Diagn Pathol ; 7: 40, 2012 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-22500694

RESUMO

BACKGROUND: The amplification of oncogenes initiated by high-risk human papillomavirus (HPV) infection is an early event in cervical carcinogenesis and can be used for cervical lesion diagnosis. We measured the genomic amplification rates and the patterns of human telomerase RNA gene (TERC) and C-MYC in the liquid-based cytological specimens to evaluate the diagnostic characteristics for the detection of high-grade cervical lesions. METHODS: Two hundred and forty-three residual cytological specimens were obtained from outpatients aged 25 to 64 years at Qilu Hospital, Shandong University. The specimens were evaluated by fluorescence in situ hybridization (FISH) using chromosome probes to TERC (3q26) and C-MYC (8q24). All of the patients underwent colposcopic examination and histological evaluation. A Chi-square test was used for categorical data analysis. RESULTS: In the normal, cervical intraepithelial neoplasia grade 1 (CIN1), grade 2 (CIN2), grade 3 (CIN3) and squamous cervical cancer (SCC) cases, the TERC positive rates were 9.2%, 17.2%, 76.2%, 100.0% and 100.0%, respectively; the C-MYC positive rates were 20.7%, 31.0%, 71.4%, 81.8% and 100.0%, respectively. The TERC and C-MYC positive rates were higher in the CIN2+ (CIN2, CIN3 and SCC) cases than in the normal and CIN1 cases (p < 0.01). Compared with cytological analysis, the TERC test showed higher sensitivity (90.0% vs. 84.0%) and higher specificity (89.6% vs. 64.3%). The C-MYC test showed lower sensitivity (80.0% vs. 84.0%) and higher specificity (77.7% vs. 64.3%). Using a cut-off value of 5% or more aberrant cells, the TERC test showed the highest combination of sensitivity and specificity. The CIN2+ group showed more high-level TERC gene copy number (GCN) cells than did the normal/CIN1 group (p < 0.05). For C-MYC, no significant difference between the two histological categories was detected (p > 0.05). CONCLUSIONS: The TERC test is highly sensitive and is therefore suitable for cervical cancer screening. The C-MYC test is not suitable for cancer screening because of its lower sensitivity. The amplification patterns of TERC become more diverse and complex as the severity of cervical diseases increases, whereas for C-MYC, the amplification patterns are similar between the normal/CIN1 and CIN2+ groups. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1308004512669913.


Assuntos
Amplificação de Genes , Genes myc/genética , RNA/genética , Telomerase/genética , Displasia do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/diagnóstico , Adulto , Técnicas Citológicas , DNA de Neoplasias/genética , Feminino , Humanos , Hibridização in Situ Fluorescente , Pessoa de Meia-Idade , Prognóstico , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia , Displasia do Colo do Útero/genética , Displasia do Colo do Útero/patologia
20.
Zhonghua Fu Chan Ke Za Zhi ; 46(7): 516-20, 2011 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-22041444

RESUMO

OBJECTIVE: To evaluate the application of pathological diagnosis by rapid paraffin sections in the diagnosis and treatment of cervical diseases. METHODS: A total of 176 cases from our hospital between September 2009 and January 2010 with abnormal cervical cancer screening (including abnormal cytology result and high-risk HPV continuous positive) were randomly divided into 2 groups. Eighty-seven cases of them whose biopsy were got by Belinson forceps under the direction of colposcopy with rapid paraffin sections by ultrasonic histopathological rapid processor and BT transparent agents were selected as group A, while 89 cases with conventional paraffin sections were selected as group B. The production time and quality for paraffin sections were analyzed in the two groups. Those diagnosed as cervical intraepithelial neoplasia (CIN) II or even worse and some special patients with CINI in the two groups received surgery, including loop electrosurgical procedure (LEEP), cold knife conization (CKC), hysterectomy or radical hysterectomy. Tissue obtained after surgery was sent for routine pathological examination. If the results of postoperative routine pathological examination were inconsistent with the rapid or routine biopsy pathological examination, the heavier results were regard as the final diagnoses. The pathological results and diagnose accordance rates were recorded and compared between group A and group B. RESULTS: The quality of sections in two groups were all satisfied or basically satisfied to meet the diagnostic requirements. There were statistically significant difference in average production time between group A and B (40 minutes vs 24 hours, P<0.05). Thirty patients in group A and 32 patients in group B received surgery. The coincidence rate of biopsy pathological results and final diagnoses were 93% (28/30) for group A and 91% (29/32) for group B, in which there were not statistically significant difference (P>0.05). CONCLUSION: Rapid paraffin sections technology is safe, accurate and economical for rapid pathological diagnosis of cervical diseases, which is worthy for being widely used in hospitals.


Assuntos
Colo do Útero/patologia , Técnicas Histológicas , Inclusão em Parafina/métodos , Displasia do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/diagnóstico , Adulto , Biópsia , Colo do Útero/cirurgia , Conização , Eletrocirurgia , Feminino , Humanos , Histerectomia , Pessoa de Meia-Idade , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/cirurgia , Adulto Jovem , Displasia do Colo do Útero/patologia , Displasia do Colo do Útero/cirurgia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA