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1.
Hum Mol Genet ; 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38723288

RESUMO

microRNAs (miRNAs) are short non-coding RNAs that have been increasingly recognized for their significant roles in the progression of cancer. Distinct miRNAs exhibit diverse functions attributed to variations in their sequences. As a result of possessing highly homologous seed sequences, these miRNAs target overlapping or similar gene sets, thus performing analogous roles. However, different from this sight, our study discovered that miR-135a-5p and miR-135b-5p, despite differing by only one nucleotide, exhibit distinct functional roles. Using non-small cell lung cancer (NSCLC) as a paradigm, our findings unveiled the downregulation of miR-135a-5p and upregulation of miR-135b-5p within NSCLC through TCGA database. Consequently, we further investigated their functional differences in A549 cells. Overexpression of miR-135b-5p enhanced the proliferation and migration capabilities of A549 cells, whereas miR-135a-5p transfection exhibited the opposite effect. We demonstrated that the activation of specific enhancers serves as a crucial mechanism underlying the disparate functions exerted by miR-135a-5p and miR-135b-5p in the context of NSCLC, consequently instigating a shift from inhibition to activation in NSCLC progression. Finally, we validated through animal experiments that miR-135b-5p promoted tumor progression, while miR-135a-5p exerted inhibitory effects on NSCLC development. This study offers a novel perspective for researchers to elucidate functional disparities exhibited by highly homologous miRNAs (miR-135a-5p and miR-135b-5p) in the context of NSCLC, along with the transition from inhibitory to progressive states in NSCLC. This study provides a solid foundation for future investigations into the functional roles of highly homologous miRNAs in pathological situation.

2.
Hum Mol Genet ; 32(1): 79-92, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-35921230

RESUMO

Non-small cell lung cancer (NSCLC) is one of the most malignant epithelial tumors. Studies have suggested that DNA hypermethylation of promoters and abnormal histone modifications could induce tumor suppressor genes (TSGs) downregulation in NSCLC. However, the exact mechanism of TSGs downregulation remains unclear. In this study, we found that there is no difference in the regions of most TSGs promoters in NSCLC. Moreover, we found that there is no DNA methylation difference in the region of VILL promoter in NSCLC compared with adjacent tissue samples by pyrosequencing. We further demonstrated that VILL was markedly reactivated in A549 and H1703 cells infected with miR-26A1 lentivirus while this activation was inhibited by JQ1, an enhancer inhibitor. In addition, we identified that miR-26A1 could function as a tumor suppressor to inhibit proliferation and metastasis of NSCLC cells. Chromatin immunoprecipitation assays revealed that overexpression of miR-26A1 could significantly induce the enrichment of H3K27ac at the enhancer regions in A549 cells. To sum up, our findings revealed that enhancer-mediated TSGs regulation occured in NSCLC, suggesting that miR-26A1 could serve as a key regulator and may be a potential therapeutic target for NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Genes Supressores de Tumor , Neoplasias Pulmonares , MicroRNAs , Humanos , Células A549 , Carcinoma Pulmonar de Células não Pequenas/genética , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica/genética , Neoplasias Pulmonares/genética , MicroRNAs/genética
3.
BMC Med ; 22(1): 55, 2024 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-38317152

RESUMO

BACKGROUND: Implementation of high-risk human papillomavirus (hrHPV) screening has greatly reduced the incidence and mortality of cervical cancer. However, a triage strategy that is effective, noninvasive, and independent from the subjective interpretation of pathologists is urgently required to decrease unnecessary colposcopy referrals in hrHPV-positive women. METHODS: A total of 3251 hrHPV-positive women aged 30-82 years (median = 41 years) from International Peace Maternity and Child Health Hospital were included in the training set (n = 2116) and the validation set (n = 1135) to establish Cervical cancer Methylation (CerMe) detection. The performance of CerMe as a triage for hrHPV-positive women was evaluated. RESULTS: CerMe detection efficiently distinguished cervical intraepithelial neoplasia grade 2 or worse (CIN2 +) from cervical intraepithelial neoplasia grade 1 or normal (CIN1 -) women with excellent sensitivity of 82.4% (95% CI = 72.6 ~ 89.8%) and specificity of 91.1% (95% CI = 89.2 ~ 92.7%). Importantly, CerMe showed improved specificity (92.1% vs. 74.9%) in other 12 hrHPV type-positive women as well as superior sensitivity (80.8% vs. 61.5%) and specificity (88.9% vs. 75.3%) in HPV16/18 type-positive women compared with cytology testing. CerMe performed well in the triage of hrHPV-positive women with ASC-US (sensitivity = 74.4%, specificity = 87.5%) or LSIL cytology (sensitivity = 84.4%, specificity = 83.9%). CONCLUSIONS: PCDHGB7 hypermethylation-based CerMe detection can be used as a triage strategy for hrHPV-positive women to reduce unnecessary over-referrals. TRIAL REGISTRATION: ChiCTR2100048972. Registered on 19 July 2021.


Assuntos
Infecções por Papillomavirus , Displasia do Colo do Útero , Neoplasias do Colo do Útero , Feminino , Humanos , Metilação de DNA , Detecção Precoce de Câncer , Papillomavirus Humano 16 , Papillomavirus Humano 18 , Papillomaviridae , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/epidemiologia , Estudos Prospectivos , Sensibilidade e Especificidade , Triagem , Displasia do Colo do Útero/diagnóstico , Displasia do Colo do Útero/epidemiologia , Displasia do Colo do Útero/genética , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/genética , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais
4.
J Transl Med ; 22(1): 608, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38956589

RESUMO

BACKGROUND: Urothelial carcinoma (UC) is the second most common urological malignancy. Despite numerous molecular markers have been evaluated during the past decades, no urothelial markers for diagnosis and recurrence monitoring have shown consistent clinical utility. METHODS: The methylation level of tissue samples from public database and clinical collected were analyzed. Patients with UC and benign diseases of the urinary system (BUD) were enrolled to establish TAGMe (TAG of Methylation) assessment in a training cohort (n = 567) using restriction enzyme-based bisulfite-free qPCR. The performance of TAGMe assessment was further verified in the validation cohort (n = 198). Urine samples from 57 UC patients undergoing postoperative surveillance were collected monthly for six months after surgery to assess the TAGMe methylation. RESULTS: We identified TAGMe as a potentially novel Universal-Cancer-Only Methylation (UCOM) marker was hypermethylated in multi-type cancers and investigated its application in UC. Restriction enzyme-based bisulfite-free qPCR was used for detection, and the results of which were consistent with gold standard pyrosequencing. Importantly, hypermethylated TAGMe showed excellent sensitivity of 88.9% (95% CI: 81.4-94.1%) and specificity of 90.0% (95% CI: 81.9-95.3%) in efficiently distinguishing UC from BUD patients in urine and also performed well in different clinical scenarios of UC. Moreover, the abnormality of TAGMe as an indicator of recurrence might precede clinical recurrence by three months to one year, which provided an invaluable time window for timely and effective intervention to prevent UC upstaging. CONCLUSION: TAGMe assessment based on a novel single target in urine is effective and easy to perform in UC diagnosis and recurrence monitoring, which may reduce the burden of cystoscopy. Trial registration ChiCTR2100052507. Registered on 30 October 2021.


Assuntos
Biomarcadores Tumorais , Metilação de DNA , Recidiva Local de Neoplasia , Humanos , Metilação de DNA/genética , Masculino , Feminino , Biomarcadores Tumorais/urina , Biomarcadores Tumorais/genética , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/diagnóstico , Idoso , Urotélio/patologia , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/diagnóstico , Neoplasias da Bexiga Urinária/urina , Estudos de Coortes , Neoplasias Urológicas/genética , Neoplasias Urológicas/diagnóstico , Neoplasias Urológicas/urina , Reprodutibilidade dos Testes , Proteínas de Membrana , Proteínas de Neoplasias
5.
Ren Fail ; 46(1): 2334406, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38575341

RESUMO

A critical event in the pathogenesis of kidney fibrosis is the transition of macrophages into myofibroblasts (MMT). Exosomes play an important role in crosstalk among cells in the kidney and the development of renal fibrosis. However, the role of myofibroblast-derived exosomes in the process of MMT and renal fibrosis progression remains unknown. Here, we examined the role of myofibroblast-derived exosomes in MMT and kidney fibrogenesis. In vitro, transforming growth factor-ß1 stimulated the differentiation of kidney fibroblasts into myofibroblasts and promoted exosome release from myofibroblasts. RAW264.7 cells were treated with exosomes derived from myofibroblasts. We found purified exosomes from myofibroblasts trigger the MMT. By contrast, inhibition of exosome production with GW4869 or exosome depletion from the conditioned media abolished the ability of myofibroblasts to induce MMT. Mice treatment with myofibroblast-derived exosomes (Myo-Exo) exhibited severe fibrotic lesion and more abundant MMT cells in kidneys with folic acid (FA) injury, which was negated by TANK-banding kinase-1 inhibitor. Furthermore, suppression of exosome production reduced collagen deposition, extracellular matrix protein accumulation, and MMT in FA nephropathy. Collectively, Myo-Exo enhances the MMT and kidney fibrosis. Blockade of exosomes mediated myofibroblasts-macrophages communication may provide a novel therapeutic target for kidney fibrosis.


Assuntos
Exossomos , Nefropatias , Animais , Camundongos , Miofibroblastos/metabolismo , Exossomos/metabolismo , Exossomos/patologia , Macrófagos/metabolismo , Nefropatias/patologia , Rim/patologia , Fibrose
6.
Semin Cancer Biol ; 83: 596-604, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-30208341

RESUMO

Various tumorigenic theories have been proposed in the past century, which contribute to the prevention and treatment of cancer clinically. However, the underlying mechanisms of the initiation of cancer, drug resistance, neoplasm relapse, and metastasis are still challenging to be panoramically addressed. Based on the abundant evidence provided by others and us, we postulate that Tumor Initiated by Loss of Cell Identity (LOCI), which is an inevitable initiating event of tumorigenesis. As a result, normal cells are transformed into the cancerous cell. In this process, epigenetic regulatory program, especially NamiRNA (Nuclear activating miRNA)-enhancer-gene activation network, is vital for the cell identity. The disorganization of NamiRNA-enhancer-gene activation network is a causal predisposition to the cell identity loss, and the altered cell identity is stabilized by genetic variations of the NamiRNA-enhancer-gene activation network. Furthermore, the additional genetic or epigenetic abnormities confer those cells to carcinogenic characteristics, such as growth advantage over normal cells, and finally yield cancer. In this review, we literally explain our tumor imitation hypothesis based on the corresponding evidence, which will not only help to refresh our understanding of tumorigenesis but also bring benefits to developing "cell identity reversing" based therapies.


Assuntos
Elementos Facilitadores Genéticos , Recidiva Local de Neoplasia , Carcinogênese/genética , Epigênese Genética , Redes Reguladoras de Genes , Humanos , Recidiva Local de Neoplasia/genética
7.
Carcinogenesis ; 44(2): 153-165, 2023 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-36591938

RESUMO

Pancreatic cancer (PaCa) is one of the most fatal malignancies of the digestive system, and most patients are diagnosed at advanced stages due to the lack of specific and effective tumor-related biomarkers for the early detection of PaCa. miR-492 has been found to be upregulated in PaCa tumor tissue and may serve as a potential therapeutic target. However, the molecular mechanisms by which miR-492 promotes PaCa tumor growth and progression are unclear. In this study, we first found that miR-492 in enhancer loci activated neighboring genes (NR2C1/NDUFA12/TMCC3) and promoted PaCa cell proliferation, migration, and invasion in vitro. We also observed that miR-492-activating genes significantly enriched the TGF-ß/Smad3 signaling pathway in PaCa to promote epithelial-mesenchymal transition (EMT) during tumorigenesis and development. Using CRISPR-Cas9 and ChIP assays, we further observed that miR-492 acted as an enhancer trigger, and that antagomiR-492 repressed PaCa tumorigenesis in vivo, decreased the expression levels of serum TGF-ß, and suppressed the EMT process by downregulating the expression of NR2C1. Our results demonstrate that miR-492, as an enhancer trigger, facilitates PaCa progression via the NR2C1-TGF-ß/Smad3 pathway.


Assuntos
MicroRNAs , Neoplasias Pancreáticas , Humanos , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , MicroRNAs/genética , Transição Epitelial-Mesenquimal/genética , Linhagem Celular Tumoral , Neoplasias Pancreáticas/genética , Carcinogênese/genética , Movimento Celular/genética , Regulação Neoplásica da Expressão Gênica , Proliferação de Células/genética , Proteína Smad3/genética , Proteína Smad3/metabolismo , NADPH Desidrogenase/genética , NADPH Desidrogenase/metabolismo , Neoplasias Pancreáticas
8.
Hum Mol Genet ; 30(22): 2110-2122, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34196368

RESUMO

The well-established functions of UHRF1 converge to DNA biological processes, as exemplified by DNA methylation maintenance and DNA damage repair during cell cycles. However, the potential effect of UHRF1 on RNA metabolism is largely unexplored. Here, we revealed that UHRF1 serves as a novel alternative RNA splicing regulator. The protein interactome of UHRF1 identified various splicing factors. Among them, SF3B3 could interact with UHRF1 directly and participate in UHRF1-regulated alternative splicing events. Furthermore, we interrogated the RNA interactome of UHRF1, and surprisingly, we identified U snRNAs, the canonical spliceosome components, in the purified UHRF1 complex. Unexpectedly, we found H3R2 methylation status determines the binding preference of U snRNAs, especially U2 snRNAs. The involvement of U snRNAs in UHRF1-containing complex and their binding preference to specific chromatin configuration imply a finely orchestrated mechanism at play. Our results provided the resources and pinpointed the molecular basis of UHRF1-mediated alternative RNA splicing, which will help us better our understanding of the physiological and pathological roles of UHRF1 in disease development.


Assuntos
Processamento Alternativo , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Histonas/metabolismo , Fatores de Processamento de RNA/metabolismo , RNA Nuclear Pequeno/genética , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Estimuladoras de Ligação a CCAAT/genética , Humanos , Metilação , Complexos Multiproteicos , Conformação de Ácido Nucleico , Ligação Proteica , RNA Nuclear Pequeno/metabolismo , Ubiquitina-Proteína Ligases/genética
9.
Br J Cancer ; 128(9): 1681-1689, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36828869

RESUMO

BACKGROUND: A major challenge in stage II colorectal carcinoma is to identify patients with increased risk of recurrence. Biomarkers that distinguish patients with poor prognosis from patients without recurrence are currently lacking. This study aims to develop a robust DNA methylation classifier that allows the prediction of recurrence and chemotherapy benefit in patients with stage II colorectal cancer. We performed a genome-wide DNA methylation capture sequencing in 243 stage II colorectal carcinoma samples and identified a relapse-specific DNA methylation signature consisting of eight CpG sites. METHODS: Two hundred and forty-three patients with stage II CRC were enrolled in this study. In order to select differential methylation sites among recurrence and non-recurrence stage II CRC samples, DNA methylation profiles of 62 tumour samples including 31 recurrence and 31 nonrecurrence samples were analysed using the Agilent SureSelectXT Human Methyl-Seq, a comprehensive target enrichment system to analyse CpG methylation. Pyrosequencing was applied to quantify the methylation level of candidate DNA methylation sites in 243 patients. Least absolute shrinkage and selection operator (LASSO) method was employed to build the disease recurrence prediction classifier. RESULTS: We identified a relapse-related DNA methylation signature consisting of eight CpG sites in stage II CRC by DNA methylation capture sequencing. The classifier showed significantly higher prognostic accuracy than any clinicopathological risk factors. The Kaplan-Meier survival curve showed an association of high-risk score with poor prognosis. In multivariate analysis, the signature was the most significant prognosis factor, with an HR of 2.80 (95% CI, 1.71-4.58, P < 0.001). The signature could identify patients who are suitable candidates for adjuvant chemotherapy. CONCLUSIONS: An eight-CpG DNA methylation signature is a reliable prognostic and predictive tool for disease recurrence in patients with stage II CRC.


Assuntos
Neoplasias Colorretais , Metilação de DNA , Humanos , Regulação Neoplásica da Expressão Gênica , Neoplasias Colorretais/patologia , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Biomarcadores Tumorais/genética , Estadiamento de Neoplasias
10.
Nucleic Acids Res ; 49(15): 8556-8572, 2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34329471

RESUMO

Dysfunction of Tumour Suppressor Genes (TSGs) is a common feature in carcinogenesis. Epigenetic abnormalities including DNA hypermethylation or aberrant histone modifications in promoter regions have been described for interpreting TSG inactivation. However, in many instances, how TSGs are silenced in tumours are largely unknown. Given that miRNA with low expression in tumours is another recognized signature, we hypothesize that low expression of miRNA may reduce the activity of TSG related enhancers and further lead to inactivation of TSG during cancer development. Here, we reported that low expression of miRNA in cancer as a recognized signature leads to loss of function of TSGs in breast cancer. In 157 paired breast cancer and adjacent normal samples, tumour suppressor gene GPER1 and miR-339 are both downregulated in Luminal A/B and Triple Negative Breast Cancer subtypes. Mechanistic investigations revealed that miR-339 upregulates GPER1 expression in breast cancer cells by switching on the GPER1 enhancer, which can be blocked by enhancer deletion through the CRISPR/Cas9 system. Collectively, our findings reveal novel mechanistic insights into TSG dysfunction in cancer development, and provide evidence that reactivation of TSG by enhancer switching may be a promising alternative strategy for clinical breast cancer treatment.


Assuntos
Neoplasias da Mama/genética , Metilação de DNA/genética , MicroRNAs/genética , Receptores de Estrogênio/genética , Receptores Acoplados a Proteínas G/genética , Proteínas Supressoras de Tumor/genética , Neoplasias da Mama/patologia , Carcinogênese/genética , Elementos Facilitadores Genéticos/genética , Epigenômica , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Inativação Gênica , Humanos , Regiões Promotoras Genéticas/genética , RNA Neoplásico/genética , Sequências Reguladoras de Ácido Nucleico/genética
11.
Genome Res ; 29(2): 270-280, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30670627

RESUMO

Aberrant DNA methylation is a distinguishing feature of cancer. Yet, how methylation affects immune surveillance and tumor metastasis remains ambiguous. We introduce a novel method, Guide Positioning Sequencing (GPS), for precisely detecting whole-genome DNA methylation with cytosine coverage as high as 96% and unbiased coverage of GC-rich and repetitive regions. Systematic comparisons of GPS with whole-genome bisulfite sequencing (WGBS) found that methylation difference between gene body and promoter is an effective predictor of gene expression with a correlation coefficient of 0.67 (GPS) versus 0.33 (WGBS). Moreover, Methylation Boundary Shift (MBS) in promoters or enhancers is capable of modulating expression of genes associated with immunity and tumor metabolism. Furthermore, aberrant DNA methylation results in tissue-specific enhancer switching, which is responsible for altering cell identity during liver cancer development. Altogether, we demonstrate that GPS is a powerful tool with improved accuracy and efficiency over WGBS in simultaneously detecting genome-wide DNA methylation and genomic variation. Using GPS, we show that aberrant DNA methylation is associated with altering cell identity and immune surveillance networks, which may contribute to tumorigenesis and metastasis.


Assuntos
Metilação de DNA , Regulação Neoplásica da Expressão Gênica , Análise de Sequência de DNA/métodos , Carcinogênese/genética , Linhagem Celular Tumoral , Elementos Facilitadores Genéticos , Genoma Humano , Humanos , Vigilância Imunológica/genética , Fígado/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Metástase Neoplásica , Regiões Promotoras Genéticas , Proteínas Ribossômicas/genética
12.
Semin Cancer Biol ; 57: 1-9, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30213688

RESUMO

Various tumorigenic theories have been proposed in the past century, which contribute to the prevention and treatment of cancer clinically. However, the underlying mechanisms of the initiation of cancer, drug resistance, neoplasm relapse, and metastasis are still challenging to be panoramically addressed. Based on the abundant evidence provided by others and us, we postulate that Tumor Initiated by Loss of Cell Identity (LOCI), which is an inevitable initiating event of tumorigenesis. As a result, normal cells are transformed into the cancerous cell. In this process, epigenetic regulatory program, especially NamiRNA (Nuclear activating miRNA)-enhancer-gene activation network, is vital for the cell identity. The disorganization of NamiRNA-enhancer-gene activation network is a causal predisposition to the cell identity loss, and the altered cell identity is stabilized by genetic variations of the NamiRNA-enhancer-gene activation network. Furthermore, the additional genetic or epigenetic abnormities confer those cells to carcinogenic characteristics, such as growth advantage over normal cells, and finally yield cancer. In this review, we literally explain our tumor initiation hypothesis based on the corresponding evidence, which will not only help to refresh our understanding of tumorigenesis but also bring benefits to developing "cell identity reversing" based therapies.


Assuntos
Transformação Celular Neoplásica/genética , Epigênese Genética , Predisposição Genética para Doença , Neoplasias/etiologia , Animais , Biomarcadores Tumorais , Ciclo Celular/genética , Transformação Celular Neoplásica/metabolismo , Elementos Facilitadores Genéticos , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Estudos de Associação Genética , Humanos , MicroRNAs/genética , Neoplasias/metabolismo , Neoplasias/patologia
13.
Hum Mol Genet ; 26(21): 4231-4243, 2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-29088426

RESUMO

Genetic and epigenetic information are faithfully duplicated and accurately transmitted to daughter cells to preserve cell identity during the cell cycle. However, how the chromatin-based epigenetic information beyond DNA sequence is stably transmitted along with the disruption and re-establishment of chromatin structure within a cell cycle remains largely unexplored. Through comprehensive analysis DNA methylation and nucleosome positioning patterns of HepG2 cells in G0/G1, early S, late S and G2/M phases, we found that DNA methylation may act as the prime element for epigenetic inheritance after replication, as DNA methylation was extremely stable in each cell cycle phase, while nucleosome occupancy showed notable phase dependent fluctuation. Nucleosome-Secured Regions (NSRs) occupied by polycomb-repressed chromatin played a role in repressing the irrelevant cell type-specific genes and were essential for preventing irrelevant transcription factors binding, while the well-defined Nucleosome-Depleted Regions (NDRs) marked the genes crucial for cell identity maintenance. Chromatin structure at NSRs and NDRs was well maintained throughout the cell cycle, which played crucial roles in steadily preserving the transcriptional identity of the cell to fulfill cell identity maintenance. Collectively, our results demonstrated that while chromatin architecture underwent dynamic changes during cell cycle progression, DNA methylation together with NSRs and NDRs were stable epigenetic elements that were required for faithful transmission to the daughter cell to accurately maintain cell identity during the cell cycle.


Assuntos
Montagem e Desmontagem da Cromatina/fisiologia , Cromatina/fisiologia , Epigênese Genética/genética , Ciclo Celular/genética , Ciclo Celular/fisiologia , Divisão Celular , Cromatina/metabolismo , Montagem e Desmontagem da Cromatina/genética , Metilação de DNA/fisiologia , Epigenômica , Células Hep G2/metabolismo , Histonas/metabolismo , Humanos , Nucleossomos/metabolismo , Nucleossomos/efeitos da radiação , Proteínas do Grupo Polycomb/genética , Fatores de Transcrição/genética
14.
J Cell Sci ; 129(5): 1059-71, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26769901

RESUMO

Ten-eleven translocation (Tet) proteins are key players involved in the dynamic regulation of cytosine methylation and demethylation. Inactivating mutations of Tet2 are frequently found in human malignancies, highlighting the essential role of Tet2 in cellular transformation. However, the factors that control Tet enzymatic activity remain largely unknown. Here, we found that methyl-CpG-binding domain protein 3 (MBD3) and its homolog MBD3-like 2 (MBD3L2) can specifically modulate the enzymatic activity of Tet2 protein, but not Tet1 and Tet3 proteins, in converting 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC). Moreover, MBD3L2 is more effective than MBD3 in promoting Tet2 enzymatic activity through strengthening the binding affinity between Tet2 and the methylated DNA target. Further analysis revealed pronounced decreases in 5mC levels at MBD3L2 and Tet2 co-occupied genomic regions, most of which are promoter elements associated with either cancer-related genes or genes involved in the regulation of cellular metabolic processes. Our data add new insights into the regulation of Tet2 activity by MBD3 and MBD3L2, and into how that affects Tet2-mediated modulation of its target genes in cancer development. Thus, they have important applications in understanding how dysregulation of Tet2 might contribute to human malignancy.


Assuntos
5-Metilcitosina/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Repressoras/fisiologia , Cromatina/metabolismo , Ilhas de CpG , Metilação de DNA , Dioxigenases , Células HEK293 , Humanos , Oxirredução , Ligação Proteica
15.
BMC Genomics ; 18(Suppl 2): 134, 2017 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-28361696

RESUMO

BACKGROUND: The increasing studies have been conducted using whole genome DNA methylation detection as one of the most important part of epigenetics research to find the significant relationships among DNA methylation and several typical diseases, such as cancers and diabetes. In many of those studies, mapping the bisulfite treated sequence to the whole genome has been the main method to study DNA cytosine methylation. However, today's relative tools almost suffer from inaccuracies and time-consuming problems. RESULTS: In our study, we designed a new DNA methylation prediction tool ("Hint-Hunt") to solve the problem. By having an optimal complex alignment computation and Smith-Waterman matrix dynamic programming, Hint-Hunt could analyze and predict the DNA methylation status. But when Hint-Hunt tried to predict DNA methylation status with large-scale dataset, there are still slow speed and low temporal-spatial efficiency problems. In order to solve the problems of Smith-Waterman dynamic programming and low temporal-spatial efficiency, we further design a deep parallelized whole genome DNA methylation detection tool ("P-Hint-Hunt") on Tianhe-2 (TH-2) supercomputer. CONCLUSIONS: To the best of our knowledge, P-Hint-Hunt is the first parallel DNA methylation detection tool with a high speed-up to process large-scale dataset, and could run both on CPU and Intel Xeon Phi coprocessors. Moreover, we deploy and evaluate Hint-Hunt and P-Hint-Hunt on TH-2 supercomputer in different scales. The experimental results illuminate our tools eliminate the deviation caused by bisulfite treatment in mapping procedure and the multi-level parallel program yields a 48 times speed-up with 64 threads. P-Hint-Hunt gain a deep acceleration on CPU and Intel Xeon Phi heterogeneous platform, which gives full play of the advantages of multi-cores (CPU) and many-cores (Phi).


Assuntos
Mapeamento Cromossômico/métodos , Biologia Computacional/métodos , Metilação de DNA , Epigênese Genética , Software , Sequência de Aminoácidos , Sequência de Bases , Citosina/metabolismo , Genoma Humano , Humanos , Alinhamento de Sequência , Análise de Sequência de DNA
16.
RNA Biol ; 14(10): 1326-1334, 2017 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-26853707

RESUMO

MicroRNAs (miRNAs) are small non-coding RNAs that function as negative gene expression regulators. Emerging evidence shows that, except for function in the cytoplasm, miRNAs are also present in the nucleus. However, the functional significance of nuclear miRNAs remains largely undetermined. By screening miRNA database, we have identified a subset of miRNA that functions as enhancer regulators. Here, we found a set of miRNAs show gene-activation function. We focused on miR-24-1 and found that this miRNA unconventionally activates gene transcription by targeting enhancers. Consistently, the activation was completely abolished when the enhancer sequence was deleted by TALEN. Furthermore, we found that miR-24-1 activates enhancer RNA (eRNA) expression, alters histone modification, and increases the enrichment of p300 and RNA Pol II at the enhancer locus. Our results demonstrate a novel mechanism of miRNA as an enhancer trigger.


Assuntos
Cromatina/metabolismo , Elementos Facilitadores Genéticos , MicroRNAs/genética , Ativação Transcricional , Cromatina/química , Bases de Dados Genéticas , Proteína p300 Associada a E1A/metabolismo , Epigênese Genética , Perfilação da Expressão Gênica/métodos , Células HEK293 , Histonas/metabolismo , Humanos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , RNA Polimerase II/metabolismo
17.
Adv Exp Med Biol ; 983: 113-125, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28639195

RESUMO

MicroRNAs (miRNAs) are small noncoding RNAs that act as negative regulators of gene expression in the cytoplasm. Yet, emerging evidence has shown that miRNAs are also distributed in the nucleus, with its function largely undetermined. At the same time, while miRNAs and enhancers show obvious tissue specificity, the interaction between miRNAs and enhancers in gene regulation remains unknown. By screening miRNA databases, we have identified a subset of miRNAs, called nuclear activating miRNAs (NamiRNAs). As enhancer regulators, NamiRNAs are able to activate gene expression at the transcriptional level. In addition, we found that the regulation of enhancers mediated by NamiRNAs depends on the presence of intact enhancers and AGO2 protein. More interesting is that NamiRNAs promote global gene transcription through the binding and activation of their targeted enhancers. Our results demonstrate a novel role for miRNA as an enhancer trigger for transcriptional gene activation. Further study of the function and molecular mechanism for NamiRNAs in tumorigenesis and development is of great significance.


Assuntos
Regulação da Expressão Gênica , MicroRNAs/genética , Ativação Transcricional , Núcleo Celular/genética
18.
Nature ; 451(7175): 202-6, 2008 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-18185590

RESUMO

Tumour suppressor genes (TSGs) inhibiting normal cellular growth are frequently silenced epigenetically in cancer. DNA methylation is commonly associated with TSG silencing, yet mutations in the DNA methylation initiation and recognition machinery in carcinogenesis are unknown. An intriguing possible mechanism for gene regulation involves widespread non-coding RNAs such as microRNA, Piwi-interacting RNA and antisense RNAs. Widespread sense-antisense transcripts have been systematically identified in mammalian cells, and global transcriptome analysis shows that up to 70% of transcripts have antisense partners and that perturbation of antisense RNA can alter the expression of the sense gene. For example, it has been shown that an antisense transcript not naturally occurring but induced by genetic mutation leads to gene silencing and DNA methylation, causing thalassaemia in a patient. Here we show that many TSGs have nearby antisense RNAs, and we focus on the role of one RNA in silencing p15, a cyclin-dependent kinase inhibitor implicated in leukaemia. We found an inverse relation between p15 antisense (p15AS) and p15 sense expression in leukaemia. A p15AS expression construct induced p15 silencing in cis and in trans through heterochromatin formation but not DNA methylation; the silencing persisted after p15AS was turned off, although methylation and heterochromatin inhibitors reversed this process. The p15AS-induced silencing was Dicer-independent. Expression of exogenous p15AS in mouse embryonic stem cells caused p15 silencing and increased growth, through heterochromatin formation, as well as DNA methylation after differentiation of the embryonic stem cells. Thus, natural antisense RNA may be a trigger for heterochromatin formation and DNA methylation in TSG silencing in tumorigenesis.


Assuntos
Inibidor de Quinase Dependente de Ciclina p15/genética , Epigênese Genética , Genes Supressores de Tumor , RNA Antissenso/genética , Animais , Diferenciação Celular , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p15/biossíntese , Metilação de DNA , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Heterocromatina/genética , Heterocromatina/metabolismo , Leucemia/genética , Camundongos , Modelos Genéticos , Regiões Promotoras Genéticas/genética , RNA Antissenso/metabolismo , Ribonuclease III/genética , Ribonuclease III/metabolismo
19.
Eur J Pharmacol ; 966: 176342, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38290569

RESUMO

The transition of acute kidney injury (AKI) to chronic kidney disease (CKD) is characterized by intense inflammation and progressive fibrosis. Remimazolam is widely used for procedural sedation in intensive care units, such as AKI patients. Remimazolam has been shown to possess anti-inflammatory and organ-protective properties. However, the role of remimazolam in inflammation and renal fibrosis following AKI remains unclear. Here, we explored the effects of remimazolam on the inflammatory response and kidney fibrogenesis of mice subjected to folic acid (FA) injury. Our results showed that remimazolam treatment alleviated kidney damage and dysfunction. Mice treated with remimazolam presented less collagen deposition in FA-injured kidneys compared with FA controls, which was accompanied by a reduction of extracellular matrix proteins accumulation and fibroblasts activation. Furthermore, remimazolam treatment reduced inflammatory cells infiltration into the kidneys of mice with FA injury and inhibited proinflammatory or profibrotic molecules expression. Finally, remimazolam treatment impaired the activation of bone marrow-derived fibroblasts and blunted the transformation of macrophages to myofibroblasts in FA nephropathy. Additionally, the benzodiazepine receptor antagonist PK-11195 partially reversed the protective effect of remimazolam on the FA-injured kidneys. Overall, remimazolam attenuates the inflammatory response and renal fibrosis development following FA-induced AKI, which may be related to the peripheral benzodiazepine receptor pathway.


Assuntos
Injúria Renal Aguda , Benzodiazepinas , Insuficiência Renal Crônica , Humanos , Camundongos , Animais , Ácido Fólico/farmacologia , Ácido Fólico/metabolismo , Receptores de GABA-A/metabolismo , Rim , Insuficiência Renal Crônica/patologia , Injúria Renal Aguda/tratamento farmacológico , Injúria Renal Aguda/prevenção & controle , Injúria Renal Aguda/induzido quimicamente , Inflamação/metabolismo , Fibrose , Camundongos Endogâmicos C57BL
20.
Onco Targets Ther ; 17: 371-381, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38765057

RESUMO

Objective: MCM5 is a DNA licensing factor involved in cell proliferation and has been previously established as an excellent biomarker in a number of malignancies. Nevertheless, the role of MCM5 in GBM has not been fully clarified. The present study aimed to investigate the potential roles of MCM5 in the treatment of GBM and to elucidate its underlying mechanism, which is beneficial for developing new therapeutic strategies and predicting prognosis. Methods: Firstly, we obtained transcriptomic and proteomic data from the TCGA and CPTAC databases on glioma patients. Employing the DeSeq2 R package, we then identified genes with joint differential expression in GBM tissues subjected to chemotherapy. To develop a prognostic risk score model, we performed univariate and multivariate Cox regression analyses. In vitro knockdown and overexpression of MCM5 were used to further investigate the biological functions of GBM cells. Additionally, we also delved into the upstream regulation of MCM5, revealing associations with several transcription factors. Finally, we investigated differences in immune cell infiltration and drug sensitivity across diverse risk groups identified in the prognostic risk model. Results: In this study, the chemotherapy-treated GBM samples exhibited consistent alterations in 46 upregulated and 94 downregulated genes at both the mRNA and protein levels. Notably, MCM5 emerged as a gene with prognostic significance as well as potential therapeutic relevance. In vitro experiments subsequently validated the role of increased MCM5 expression in promoting GBM cell proliferation and resistance to TMZ. Correlations with transcription factors such as CREB1, CTCF, NFYB, NRF1, PBX1, TEAD1, and USF1 were discovered during upstream regulatory analysis, enriching our understanding of MCM5 regulatory mechanisms. The study additionally delves into immune cell infiltration and drug sensitivity, providing valuable insights for personalized treatment approaches. Conclusion: This study identifies MCM5 as a key player in GBM, demonstrating its prognostic significance and potential therapeutic relevance by elucidating its role in promoting cell proliferation and resistance to chemotherapy.

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