RESUMEN
Diffuse large B-cell lymphoma (DLBCL) is the most common B-cell malignancy worldwide. Molecular classifications have tried to improve cure rates. We prospectively examined and correlated the mutational landscape with the clinical features and outcomes of 185 Mexican patients (median age 59.3 years, 50% women) with newly diagnosed DLBCL. A customized panel of 79 genes was designed, based on previous international series. Most patients had ECOG performance status (PS) < 2 (69.2%), advanced-stage disease (72.4%), germinal-center phenotype (68.1%), and double-hit lymphomas (14.1%). One hundred and ten (59.5%) patients had at least one gene with driver mutations. The most common mutated genes were as follows: TP53, EZH2, CREBBP, NOTCH1, and KMT2D. The median follow-up was 42 months, and the 5-year relapse-free survival (RFS) and overall survival (OS) rates were 70% and 72%, respectively. In the multivariate analysis, both age > 50 years and ECOG PS > 2 were significantly associated with a worse OS. Our investigation did not reveal any discernible correlation between the presence of a specific mutation and survival. In conclusion, using a customized panel, we characterized the mutational landscape of a large cohort of Mexican DLBCL patients. These results need to be confirmed in further studies.
Asunto(s)
Proteína Potenciadora del Homólogo Zeste 2 , Linfoma de Células B Grandes Difuso , Mutación , Humanos , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/mortalidad , Femenino , Persona de Mediana Edad , Masculino , México/epidemiología , Anciano , Adulto , Proteína Potenciadora del Homólogo Zeste 2/genética , Anciano de 80 o más Años , Estudios Prospectivos , Receptor Notch1/genética , Proteína de Unión a CREB/genética , Proteína p53 Supresora de Tumor/genética , Proteínas de Neoplasias/genética , Adulto Joven , Pronóstico , Adolescente , Proteínas de Unión al ADNRESUMEN
Anaplastic thyroid cancer (ATC) is a rare and lethal form of thyroid cancer that requires urgent investigation of new molecular targets involved in its aggressive biology. In this context, the overactivation of Polycomb Repressive Complex 2/EZH2, which induces chromatin compaction, is frequently observed in aggressive solid tumors, making the EZH2 methyltransferase a potential target for treatment. However, the deregulation of chromatin accessibility is yet not fully investigated in thyroid cancer. In this study, EZH2 expression was modulated by CRISPR/Cas9-mediated gene editing and pharmacologically inhibited with EZH2 inhibitor EPZ6438 alone or in combination with the MAPK inhibitor U0126. The results showed that CRISPR/Cas9-induced EZH2 gene editing reduced cell growth, migration and invasion in vitro and resulted in a 90% reduction in tumor growth when EZH2-edited cells were injected into an immunocompromised mouse model. Immunohistochemistry analysis of the tumors revealed reduced tumor cell proliferation and less recruitment of cancer-associated fibroblasts in the EZH2-edited tumors compared to the control tumors. Moreover, EZH2 inhibition induced thyroid-differentiation genes' expression and mesenchymal-to-epithelial transition (MET) in ATC cells. Thus, this study shows that targeting EZH2 could be a promising neoadjuvant treatment for ATC, as it promotes antitumoral effects in vitro and in vivo and induces cell differentiation.
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Carcinoma Anaplásico de Tiroides , Neoplasias de la Tiroides , Animales , Ratones , Línea Celular Tumoral , Proliferación Celular , Proteína Potenciadora del Homólogo Zeste 2/genética , Complejo Represivo Polycomb 2/metabolismo , Carcinoma Anaplásico de Tiroides/tratamiento farmacológico , Carcinoma Anaplásico de Tiroides/genética , Carcinoma Anaplásico de Tiroides/metabolismo , Neoplasias de la Tiroides/tratamiento farmacológico , Neoplasias de la Tiroides/genética , Neoplasias de la Tiroides/metabolismo , HumanosRESUMEN
OBJECTIVE: Breast cancer is the most common malignancy in women. In the treatment of these patients, pathological complete response is defined as the absence of invasive cancer in breast or lymph node tissue after the completion of neoadjuvant chemotherapy. In this study, we aimed to investigate the relationship of enhancer of zeste homolog 2 and mucin 1 expressions with pathological complete response in patients with breast cancer receiving neoadjuvant chemotherapy. METHODS: A total of 151 patients were included in the study. Enhancer of zeste homolog 2 and mucin 1 expressions were evaluated in the biopsy materials pre-neoadjuvant chemotherapy and post-neoadjuvant chemotherapy surgical material, and their relationship with pathological complete response was investigated. RESULTS: The pathological complete response rates were significantly higher among the hormone receptor-negative patients, those with a high Ki-67 score, and patients with HER2-positive. Higher pathological complete response rates were obtained from patients with enhancer of zeste homolog 2 expression positivity pre-neoadjuvant chemotherapy. In addition, after neoadjuvant chemotherapy, enhancer of zeste homolog 2 expression was found to be completely negative in materials with pathological complete response; that is, in breast tissues considered to be tumor-free. While there was no significant relationship between mucin 1 expression and pathological complete response pre-neoadjuvant chemotherapy, mucin 1 expression was determined to significantly differ between the tissues with and without pathological complete response among the surgical materials examined. CONCLUSION: In our study investigating the relationship between enhancer of zeste homolog 2 and mucin 1 expression and pathological complete response in patients who received neoadjuvant chemotherapy, we found that enhancer of zeste homolog 2 expression could be used as a predictive marker for pathological complete response. However, mucin 1 expression was not associated with pathological complete response.
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Neoplasias de la Mama , Proteína Potenciadora del Homólogo Zeste 2 , Mucina-1 , Femenino , Humanos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Proteína Potenciadora del Homólogo Zeste 2/genética , Mucina-1/genética , Estadificación de Neoplasias , Receptor ErbB-2/metabolismoRESUMEN
OBJECTIVE: The authors searched for genetic and transcriptional signatures associated with tumor progression and recurrence in their cohort of patients with meningiomas, combining the analysis of targeted exome, NF2-LOH, transcriptome, and protein expressions. METHODS: The authors included 91 patients who underwent resection of intracranial meningioma at their institution between June 2000 and November 2007. The search of somatic mutations was performed by Next Generation Sequencing through a customized panel and multiplex ligation-dependent probe amplification for NF2 loss of heterozygosity. The transcriptomic profile was analyzed by QuantSeq 3' mRNA-Seq. The differentially expressed genes of interest were validated at the protein level analysis by immunohistochemistry. RESULTS: The transcriptomic analysis identified an upregulated set of genes related to metabolism and cell cycle and downregulated genes related to immune response and extracellular matrix remodeling in grade 2 (atypical) meningiomas, with a significant difference in recurrent compared with nonrecurrent cases. EZH2 nuclear positivity associated with grade 2, particularly with recurrent tumors and EZH2 gene expression level, correlated positively with the expression of genes related to cell cycle and negatively to genes related to immune response and regulation of cell motility. CONCLUSIONS: The authors identified modules of dysregulated genes in grade 2 meningiomas related to the activation of oxidative metabolism, cell division, cell motility due to extracellular remodeling, and immune evasion that were predictive of survival and exhibited significant correlations with EZH2 expression.
Asunto(s)
Neoplasias Meníngeas , Meningioma , Humanos , Meningioma/cirugía , Neoplasias Meníngeas/cirugía , Recurrencia Local de Neoplasia/patología , Ciclo Celular , División Celular , Proteína Potenciadora del Homólogo Zeste 2/genéticaRESUMEN
OBJECTIVE: Long Non-Coding RNAs (LncRNAs) act as an indispensable role in cancer development. The study aimed to investigate the role and mechanism of lncRNA Small Nucleolar RNA Host Gene 1 (SNHG1) in Bladder Cancer (BC) progression. METHOD: The expression, prognostic value, diagnostic value, and correlation of SNHG1, Enhancer of Zeste 2 polycomb repressive complex 2 subunit (EZH2), and Kruppel Like Factor 2 (KLF2) were analyzed through bioinformatics analysis. The expression was also validated in BC tissues and cell lines. Besides, their regulation and binding were tested via qPCR, Western blot, Dual-Luciferase Reporter Assay (DLRA), Argonaute RISC catalytic component 2-RNA Immunoprecipitation (AGO2-RIP), and Chromatin Immunoprecipitation (ChIP). A xenograft model in nude mice was also established. RESULTS: SNHG1 was significantly overexpressed in BC tissues and cells. Importantly, SNHG1 was associated with poor survival, and ROC curves revealed high diagnostic values. Moreover, by CCK8, wound healing, transwell, and Western blot analysis, SNHG1 knockdown significantly inhibited the proliferation, migration, invasion, and epithelial-mesenchymal transition of BC cells. Additionally, in vivo experiments showed that silencing SNHG1 hindered tumorigenesis and tumor growth. Regarding mechanism, the results of AGO2-RIP, ChIP or DLRA showed that SNHG1 played different roles at diverse subcellular sites. In the cytoplasm, SNHG1 acted as a competing endogenous RNA for miR-137-3p to promote EZH2 expression. In the nucleus, SNHG1 could interact with EZH2 to inhibit KLF2 transcription. CONCLUSION: Our study elucidated that SNHG1 formed a regulatory network and played an oncogenic role in BC, which provided a novel therapeutic target for BC treatment.
Asunto(s)
Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Factores de Transcripción de Tipo Kruppel/metabolismo , MicroARNs , ARN Largo no Codificante , Neoplasias de la Vejiga Urinaria , Animales , Carcinogénesis , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Proteína Potenciadora del Homólogo Zeste 2/genética , Regulación Neoplásica de la Expresión Génica , Humanos , Factores de Transcripción de Tipo Kruppel/genética , Ratones , Ratones Desnudos , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Neoplasias de la Vejiga Urinaria/genéticaRESUMEN
Glioblastomas (GBM) are the most frequent and aggressive brain tumors. 17ß-estradiol (E2) increases proliferation, migration, and invasion of human GBM cells; however underlying mechanisms are no fully understood. Zeste 2 Enhancer Homologous enzyme (EZH2) is a methyltransferase part of Polycomb 2 repressor complex (PRC2). In GBM, EZH2 is overexpressed and involved in the cell cycle, migration, and invasion processes. We studied the role of EZH2 in the pro-oncogenic actions of E2 in human GBM cells. EZH2 gene silencing and pharmacological inhibition of EZH2 blocked proliferation, migration, and invasion of GBM cells induced by E2. We identified in silico additional putative estrogen response elements (EREs) at the EZH2 promoter, but E2 did not modify EZH2 expression. In silico analysis also revealed that among human GBM samples, EZH2 expression was homogeneous; in contrast, the heterogeneous expression of estrogen receptors (ERs) allowed the classification of the samples into groups. Even in the GBM cluster with high expression of ERs and those of their target genes, the expression of PCR2 target genes did not change. Overall, our data suggest that in GBM cells, pro-oncogenic actions of E2 are mediated by EZH2, without changes in EZH2 expression and by mechanisms that appear to be unrelated to the transcriptional activity of ERs.
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Proteína Potenciadora del Homólogo Zeste 2 , Glioblastoma , Movimiento Celular/genética , Proliferación Celular , Proteína Potenciadora del Homólogo Zeste 2/genética , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Estradiol/farmacología , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/patología , HumanosRESUMEN
BACKGROUND: Novel prognostic factors in patients with diffuse large B-cell lymphoma (DLBCL) are required in the era of Rituximab. OBJECTIVE: The objective of the study was to study the prognostic impact of exon-16 enhancer-of-zeste homolog-2 (EZH2) mutations in patients with DLBCL. METHODS: In a cohort of patients with DLBCL treated between 2015 and 2017, we analyzed the presence of EZH2 mutations and their association with clinical response (CR), relapse, progression-free survival (PFS), and overall survival (OS). RESULTS: A total of 198 patients were included; of them, 30 (15.2%) had mutations at codon 641, in exon 16 of EZH2. Response was achieved in 151 patients (76.3%), and 43 (21.7%) relapsed or progressed during follow-up. EZH2 mutations were associated with relapse/progression (risk ratio [RR] 1.18; 95% confidence interval [CI] 0.98-1.42; p = 0.031), while a trend for not achieving a complete response was observed (RR: 0.876; 95%CI 0.74-1.038; p = 0.071). Of note, Tyr641His and Tyr641Ser EZH2 mutations were associated with shorter PFS (hazard ratio 3.234; 95% CI 1.149-9.1; p = 0.026). CONCLUSION: The presence of EZH2 mutations was negatively associated with relapse/progression and showed a trend for lack of complete response. Further studies are needed to define better the prognostic significance of these mutations in Mexican-Mestizo DLBCL patients.
Asunto(s)
Proteína Potenciadora del Homólogo Zeste 2 , Linfoma de Células B Grandes Difuso , Recurrencia Local de Neoplasia , Protocolos de Quimioterapia Combinada Antineoplásica , Estudios de Cohortes , Proteína Potenciadora del Homólogo Zeste 2/genética , Exones , Humanos , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/genética , Mutación , Pronóstico , RituximabRESUMEN
BACKGROUND: Androgen receptor (AR) and polycomb repressive complex 2 (PRC2) are known to co-occupy the loci of genes that are downregulated by androgen-stimulus. Long intergenic non-coding RNA (lincRNA) PVT1 is an overexpressed oncogene that is associated with AR in LNCaP prostate cancer cells, and with PRC2 in HeLa and many other types of cancer cells. The possible involvement of PVT1 in mediating androgen-induced gene expression downregulation in prostate cancer has not been explored. METHODS: LNCaP cell line was used. Native RNA-binding-protein immunoprecipitation with anti-AR or anti-EZH2 was followed by RT-qPCR with primers for PVT1. Knockdown of PVT1 with specific GapmeRs (or a control with scrambled GapmeR) was followed by differentially expressed genes (DEGs) determination with Agilent microarrays and with Significance Analysis of Microarrays statistical test. DEGs were tested as a tumor risk classifier with a machine learning Random Forest algorithm run with gene expression data from all TCGA-PRAD (prostate adenocarcinoma) tumors as input. ChIP-qPCR was performed for histone marks at the promoter of one DEG. RESULTS: We show that PVT1 knockdown in androgen-stimulated LNCaP cells caused statistically significant expression upregulation/downregulation of hundreds of genes. Interestingly, PVT1 knockdown caused upregulation of 160 genes that were repressed by androgen, including a significantly enriched set of tumor suppressor genes, and among them FAS, NOV/CCN3, BMF, HRK, IFIT2, AJUBA, DRAIC and TNFRSF21. A 121-gene-set (out of the 160) was able to correctly predict the classification of all 293 intermediate- and high-risk TCGA-PRAD tumors, with a mean ROC area under the curve AUC = 0.89 ± 0.04, pointing to the relevance of these genes in cancer aggressiveness. Native RIP-qPCR in LNCaP showed that PVT1 was associated with EZH2, a component of PRC2. PVT1 knockdown followed by ChIP-qPCR showed significant epigenetic remodeling at the enhancer and promoter regions of tumor suppressor gene NOV, one of the androgen-repressed genes that were upregulated upon PVT1 silencing. CONCLUSIONS: Overall, we provide first evidence that PVT1 was involved in signaling a genome-wide androgen-dependent transcriptional repressive program of tumor suppressor protein-coding genes in prostate cancer cells. Identification of transcriptional inhibition of tumor suppressor genes by PVT1 highlights the pathway to the investigation of mechanisms that lie behind the oncogenic role of PVT1 in cancer. Video Abstract.
Asunto(s)
Regulación Neoplásica de la Expresión Génica , Neoplasias de la Próstata/genética , ARN Largo no Codificante/genética , Andrógenos , Línea Celular Tumoral , Proteína Potenciadora del Homólogo Zeste 2/genética , Humanos , Estimación de Kaplan-Meier , Masculino , Neoplasias de la Próstata/mortalidad , Receptores Androgénicos/genética , Transducción de Señal , Proteínas Supresoras de Tumor/genéticaRESUMEN
AIMS: Diffuse large B-cell lymphoma (DLBCL) is the most common type of aggressive lymphoma. This study was designed to compare epigenetic alterations observed in Enhancer of Zeste Homolog 2 (EZH2)-target genes between plasma-derived exosomes and primary tumors in DLBCL patients. MAIN METHODS: Exosomes were isolated from plasma of 21 DLBCL patients and 21 controls. We analyzed the methylation status of the target genes using methylation-specific PCR. We also examined whether the exosomes and the tumor samples contained transcripts of the target genes. KEY FINDINGS: We found that CDKN2A and CDKN2B were methylated in both plasma exosomes and primary tumor tissue samples. None of the transcripts were found in the exosomes except CDKN1B which was expressed in 8 (38%) of the exosome samples. SIGNIFICANCE: This study showed that plasma exosomes might preferably package certain target molecules from primary tumors and the exosomes containing dual methylated DNAs of CDKN2A and CDKN2B, or CDKN1B transcript may contribute to DLBCL pathogenesis.
Asunto(s)
Metilación de ADN , Proteína Potenciadora del Homólogo Zeste 2/biosíntesis , Proteína Potenciadora del Homólogo Zeste 2/genética , Exosomas/genética , Regulación Neoplásica de la Expresión Génica , Linfoma de Células B Grandes Difuso/genética , Humanos , Linfoma de Células B Grandes Difuso/sangreRESUMEN
Ezh2 is a catalytic subunit of the polycomb repressive complex 2 (PRC2) which mediates epigenetic gene silencing through depositing the mark histone H3 lysine 27 trimethylation (H3K27me3) at target genomic sequences. Previous studies have demonstrated that Enhancer of Zeste Homolog 2 (Ezh2) was differentially expressed during maturation of hippocampal neurons; in immature neurons, Ezh2 was abundantly expressed, whereas in mature neurons the expression Ezh2 was significantly reduced. Here, we report that Ezh2 is downregulated by microRNAs (miRs) that are expressed during the hippocampal maturation process. We show that, in mature hippocampal neurons, lethal-7 (let-7) and microRNA-124 (miR-124) are robustly expressed and can target cognate motifs at the 3'-UTR of the Ezh2 gene sequence to downregulate Ezh2 expression. Together, these data demonstrate that the PRC2 repressive activity during hippocampal maturation is controlled through a post-transcriptional mechanism that mediates Ezh2 downregulation in mature neurons.
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Regulación hacia Abajo/genética , Proteína Potenciadora del Homólogo Zeste 2/genética , Hipocampo/fisiología , MicroARNs/genética , Neuronas/fisiología , Regiones no Traducidas 3'/genética , Animales , Línea Celular , Epigénesis Genética/genética , Femenino , Células HEK293 , Histonas/genética , Humanos , Complejo Represivo Polycomb 2/genética , Embarazo , Interferencia de ARN/fisiología , Ratas , Ratas Sprague-DawleyRESUMEN
Inhibition of the H3K79 histone methyltransferase DOT1L has exhibited encouraging preclinical and early clinical activity in KMT2A (MLL)-rearranged leukemia, supporting the development of combinatorial therapies. Here, we investigated two novel combinations: dual inhibition of the histone methyltransferases DOT1L and EZH2, and the combination with a protein synthesis inhibitor. EZH2 is the catalytic subunit in the polycomb repressive complex 2 (PRC2), and inhibition of EZH2 has been reported to have preclinical activity in KMT2A-r leukemia. When combined with DOT1L inhibition, however, we observed both synergistic and antagonistic effects. Interestingly, antagonistic effects were not due to PRC2-mediated de-repression of HOXA9. HOXA cluster genes are key canonical targets of both KMT2A and the PRC2 complex. The independence of the HOXA cluster from PRC2 repression in KMT2A-r leukemia thus affords important insights into leukemia biology. Further studies revealed that EZH2 inhibition counteracted the effect of DOT1L inhibition on ribosomal gene expression. We thus identified a previously unrecognized role of DOT1L in regulating protein production. Decreased translation was one of the earliest effects measurable after DOT1L inhibition and specific to KMT2A-rearranged cell lines. H3K79me2 chromatin immunoprecipitation sequencing patterns over ribosomal genes were similar to those of the canonical KMT2A-fusion target genes in primary AML patient samples. The effects of DOT1L inhibition on ribosomal gene expression prompted us to evaluate the combination of EPZ5676 with a protein translation inhibitor. EPZ5676 was synergistic with the protein translation inhibitor homoharringtonine (omacetaxine), supporting further preclinical/clinical development of this combination. In summary, we discovered a novel epigenetic regulation of a metabolic process-protein synthesis-that plays a role in leukemogenesis and affords a combinatorial therapeutic opportunity.
Asunto(s)
Epigénesis Genética , Regulación Leucémica de la Expresión Génica , Reordenamiento Génico , Leucemia Mieloide Aguda/metabolismo , Biosíntesis de Proteínas , Línea Celular Tumoral , Proteína Potenciadora del Homólogo Zeste 2/antagonistas & inhibidores , Proteína Potenciadora del Homólogo Zeste 2/genética , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , N-Metiltransferasa de Histona-Lisina/antagonistas & inhibidores , N-Metiltransferasa de Histona-Lisina/genética , N-Metiltransferasa de Histona-Lisina/metabolismo , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patología , Proteína de la Leucemia Mieloide-Linfoide/antagonistas & inhibidores , Proteína de la Leucemia Mieloide-Linfoide/genética , Complejo Represivo Polycomb 2/genética , Complejo Represivo Polycomb 2/metabolismoRESUMEN
EZH2 is an important epigenetic regulator, but its role in diffuse large B-cell lymphoma (DLBCL) pathogenesis and its relationship with MYC, BCL2, and TP53 expression, chromosomal rearrangements, and clinical features are still poorly understood. So, we investigated EZH2 expression and its associations with the immunophenotypic presentations, including MYC, BCL2, and TP53 expression, MYC, BCL2, and BCL6 translocation status, clinicopathological features, and therapeutic response to R-CHOP in a series of 139 DLBCL cases. EZH2 positivity was associated with MYC and TP53 expression (p = 0.0002 and p = 0.0000, respectively) and to high proliferative index (Ki67>70%, p = 0.0082). No associations were found among EZH2 expression and chromosomal translocation status. The non-germinal center (nGC) DLBCL presented most of associations observed in the general sample; however, only TP53 immunodetection showed associations with EZH2 expression in the germinal center (GC) DLBCL. EZH2 expression had no impact on therapeutic efficacy in R-CHOP-treated patients. In conclusion, EZH2 seems to be upregulated by MYC, to rely on TP53 alterations, and is associated with high proliferative tumors in DLBCL, which might be dependent on GC or nGC subclassifications. Furthermore, it is not a therapeutic efficacy marker to R-CHOP in our series.
Asunto(s)
Proteína Potenciadora del Homólogo Zeste 2/genética , Linfoma de Células B Grandes Difuso/genética , Proteínas Proto-Oncogénicas c-myc/genética , Proteína p53 Supresora de Tumor/genética , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/genética , Proliferación Celular/genética , Femenino , Regulación Neoplásica de la Expresión Génica/genética , Centro Germinal/fisiología , Humanos , Masculino , Persona de Mediana Edad , Translocación Genética/genética , Regulación hacia Arriba/genética , Adulto JovenRESUMEN
Epigenetic control is critical for the regulation of gene transcription in mammalian cells. Among the most important epigenetic mechanisms are those associated with posttranslational modifications of chromosomal histone proteins, which modulate chromatin structure and increased accessibility of promoter regulatory elements for competency to support transcription. A critical histone mark is trimethylation of histone H3 at lysine residue 27 (H3K27me3), which is mediated by Ezh2, the catalytic subunit of the polycomb group complex PRC2 to repress transcription. Treatment of cells with the active vitamin D metabolite 1,25(OH)2 D3 , results in transcriptional activation of the CYP24A1 gene, which encodes a 24-hydroxylase enzyme, that is, essential for physiological control of vitamin D3 levels. We report that the Ezh2-mediated deposition of H3K27me3 at the CYP24A1 gene promoter is a requisite regulatory component during transcriptional silencing of this gene in osteoblastic cells in the absence of 1,25(OH)2 D3 . 1,25(OH)2 D3 dependent transcriptional activation of the CYP24A1 gene is accompanied by a rapid release of Ezh2 from the promoter, together with the binding of the H3K27me3-specific demethylase Utx/Kdm6a and thereby subsequent erasing of the H3K27me3 mark. Importantly, we find that these changes in H3K27me3 enrichment at the CYP24A1 gene promoter are highly dynamic, as this modification is rapidly reacquired following the withdrawal of 1,25(OH)2 D3 .
Asunto(s)
Colecalciferol/genética , Proteína Potenciadora del Homólogo Zeste 2/genética , Osteosarcoma/genética , Vitamina D3 24-Hidroxilasa/genética , Animales , Línea Celular Tumoral , Epigénesis Genética/genética , Regulación del Desarrollo de la Expresión Génica/genética , Código de Histonas/genética , Humanos , Osteoblastos/metabolismo , Osteosarcoma/patología , Regiones Promotoras Genéticas/genética , Procesamiento Proteico-Postraduccional/genética , Ratas , Activación Transcripcional/genéticaRESUMEN
Pediatric myelodysplastic syndrome (MDS) is an uncommon disease and little is known about the molecular alterations of its development and evolution to acute myeloid leukemia (AML). The Enhancer of Zeste Homolog 2 (EZH2) is the catalytic subunit of Polycomb repressive complex 2 (PCR2). It is a histone methyltransferase, that targets lysine 27 of histone 3. This methylated H3-K27 is usually associated with the silencing of genes that are involved in fundamental cellular processes, such as cell proliferation and differentiation. There are only few studies showing the status of EZH2 expression in patients with MDS and they were performed in adult MDS patients. The aim of this study was to analyze the EZH2 expression in pediatric patients with MDS and its association with karyotypes and evolution to acute myeloid leukemia (AML). We conducted the first study of EZH2 expression in pediatric patients with MDS. Considering the EZH2 expression levels in 42 patients and 17 healthy pediatric donors, it was possible to define three groups of expression in patients: low, intermediate, and high. The intermediate level encompassed patients with normal karyotypes, low level included patients with monosomy 7 and del(7q) and high level included patients with trisomy 8 and del(11q) (p < 0.0001). Comparing the leukemic evolution, the low expression group presented disease evolution in 100% (8/8) of the cases, the intermediate expression group showed disease evolution in 4.34% (1/23) and in the high expression group, 63.63% (7/11) patients showed evolution from MDS to AML (p < 0.0001). It is important to note that low and high EZH2 expression are associated with leukemic evolution, however low expression showed a stronger association with evolution from MDS to AML than the high expression. Our results suggest a scale of measure for EZH2 expression in pediatric MDS, where aberrant EZH2 expression may be a potential biomarker of disease evolution.
Asunto(s)
Biomarcadores de Tumor/biosíntesis , Proteína Potenciadora del Homólogo Zeste 2/biosíntesis , Regulación Leucémica de la Expresión Génica , Leucemia Mieloide Aguda/metabolismo , Síndromes Mielodisplásicos/metabolismo , Proteínas de Neoplasias/biosíntesis , Adolescente , Biomarcadores de Tumor/genética , Niño , Preescolar , Proteína Potenciadora del Homólogo Zeste 2/genética , Femenino , Humanos , Lactante , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patología , Masculino , Síndromes Mielodisplásicos/genética , Síndromes Mielodisplásicos/patología , Proteínas de Neoplasias/genéticaRESUMEN
Ribavirin exhibits inhibitory effects on the epigenetic enzyme enhancer of zeste homolog 2 (EZH2), which participates in lymphomagenesis. Additionally, preclinical and clinical studies have demonstrated the antilymphoma activity of this drug. To further investigate the potential of ribavirin as an anticancer treatment for lymphoma, the tumorsuppressive effects of ribavirin were analyzed in lymphoma cell lines. The effects of ribavirin on the viability and clonogenicity of the Bcell lymphoma cell line Pfeiffer (EZH2mutant), Toledo (EZH2 wildtype) and cutaneous Tcell lymphoma Hut78 cell line were assessed. Expression of EZH2 and trimethylation status of histone 3, lysine 27 trimethylated (H3K27m3) was also determined in response to ribavirin. The transcriptional effects of ribavirin on Hut78 cells were analyzed by microarray expression and the results were validated by reverse transcriptionquantitative polymerase chain reaction, western blotting and knockout of signal transducer and activator of transcription 1 (STAT1). The results of the present study demonstrated that ribavirin suppressed the growth and clonogenicity of cells in a dosedependent manner. Ribavirin did not affect the expression of EZH2 nor altered its activity as evaluated by H3K27 trimethylation status. Furthermore, the results of transcriptome analysis indicated that the majority of the canonical pathways affected by ribavirin were associated with the immune system, including 'antigen presentation', 'communication between innate and adaptive immune cells' and 'crosstalk between dendritic and natural killer cells'. The results of gene expression analysis were confirmed, by demonstrating at the RNA and protein levels, downregulation of stearoylCoA desaturase and upregulation of STAT1. Depletion of STAT1, which was proposed as a key regulator of the aforementioned pathways, exerted growth inhibitory effects almost to the same extent as ribavirin. In conclusion, ribavirin was proposed to exert growth inhibitory effects on lymphoma cell lines, particularly Hut78 cells, a cutaneous Tcell lymphoma cell line. Of note, these effects may depend on, at least in part, the activation of canonical immune pathways regulated by the key factors STAT1 and interferonγ. Our results provide insight into the antilymphoma potential of ribavirin; however, further investigations in preclinical and clinical studies are required to determine the effectiveness of ribavirin as a therapeutic agent for treating lymphoma.
Asunto(s)
Antivirales/farmacología , Apoptosis/efectos de los fármacos , Biomarcadores de Tumor/genética , Proliferación Celular/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Linfoma/patología , Ribavirina/farmacología , Biomarcadores de Tumor/metabolismo , Metilación de ADN , Proteína Potenciadora del Homólogo Zeste 2/genética , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Epigenómica , Perfilación de la Expresión Génica , Humanos , Linfoma/tratamiento farmacológico , Linfoma/genética , Linfoma/metabolismo , Células Tumorales CultivadasRESUMEN
RATIONALE: The gene deletion (5)(q22q35) is reported in 10-20% of myelodysplastic syndrome (MDS) cases and is associated with response to lenalidomide and favorable prognosis. The authors report here a clinical case of MDS transformation to B-cell acute lymphocytic leukemia (B-ALL) with an associated accrual of an additional mutation following treatment with lenalidomide. PATIENT CONCERNS: A 69-year-old man presented with progressive anemia, normal white blood cell count, and thrombocytopenia consistent with MDS. He was administered lenalidomide for 27 months, then developed acute B-cell lymphocytic leukemia and acquired a previously unreported mutation in the gene enhancer of zeste homolog 2 (EZH2). DIAGNOSES: After 27 months of therapy with lenalidomide, a surveillance bone marrow aspiration (BMA) revealed 90% cellularity with persistent multilineage dysplasia and a population of blasts comprising 54% of all bone marrow elements by morphology, consistent with B-ALL, even though the patient was asymptomatic. Conventional karyotype showed no signs of del(5)(q22q35) MDS, however bone marrow next-generation sequencing (NGS) demonstrated the accrual of a nonsense mutation (c.211del pL71*) in exon 3 of EZH2. A confirmatory BMA yielded 70% blasts and clinical features indicative of B-ALL. INTERVENTIONS: Mini-hyper-CVD (cyclophosphamide and dexamethasone at 50% dose reduction, no anthracycline, methotrexate at 75% dose reduction, cytarabine at 0.5âg/mâ×â4 doses) was administered for 21 days. OUTCOMES: A follow-up BMA was performed 2 months after mini-hyper-CVD therapy, showing dysplastic features with 25% ring sideroblasts, but no evidence of B-ALL. The patient is currently receiving monthly-low dose decitabine, ofatumumab, and dexamethasone, and is transfusion independent and asymptomatic after 7 cycles. LESSONS: The present study shows an extremely rare progression of del(5)(q22q35) MDS to B-ALL with accompanying NGS data and a newly described acquisition of an EZH2 frameshift mutation. This case highlights the importance of NGS as a diagnostic and surveillance tool for MDS.
Asunto(s)
Linfocitos B/patología , Proteína Potenciadora del Homólogo Zeste 2/genética , Síndromes Mielodisplásicos/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Anciano , Anemia/complicaciones , Inhibidores de la Angiogénesis/uso terapéutico , Antineoplásicos Alquilantes/uso terapéutico , Antineoplásicos Hormonales/uso terapéutico , Médula Ósea/patología , Deleción Cromosómica , Ciclofosfamida/administración & dosificación , Ciclofosfamida/uso terapéutico , Dexametasona/administración & dosificación , Dexametasona/uso terapéutico , Progresión de la Enfermedad , Humanos , Lenalidomida/administración & dosificación , Lenalidomida/uso terapéutico , Masculino , Mutación , Síndromes Mielodisplásicos/complicaciones , Síndromes Mielodisplásicos/tratamiento farmacológico , Síndromes Mielodisplásicos/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Trombocitopenia/complicaciones , Resultado del TratamientoRESUMEN
BACKGROUND: Cemento-ossifying fibroma (COF) is a benign fibro-osseous neoplasm of uncertain pathogenesis, and its treatment results in morbidity. MicroRNAs (miRNA) are small non-coding RNAs that regulate gene expression and may represent therapeutic targets. The purpose of the study was to generate a comprehensive miRNA profile of COF compared to normal bone. Additionally, the most relevant pathways and target genes of differentially expressed miRNA were investigated by in silico analysis. METHODS: Nine COF and ten normal bone samples were included in the study. miRNA profiling was carried out by using TaqMan® OpenArray® Human microRNA panel containing 754 validated human miRNAs. We identified the most relevant miRNAs target genes through the leader gene approach, using STRING and Cytoscape software. Pathways enrichment analysis was performed using DIANA-miRPath. RESULTS: Eleven miRNAs were downregulated (hsa-miR-95-3p, hsa-miR-141-3p, hsa-miR-205-5p, hsa-miR-223-3p, hsa-miR-31-5p, hsa-miR-944, hsa-miR-200b-3p, hsa-miR-135b-5p, hsa-miR-31-3p, hsa-miR-223-5p and hsa-miR-200c-3p), and five were upregulated (hsa-miR-181a-5p, hsa-miR-181c-5p, hsa-miR-149-5p, hsa-miR-138-5p and hsa-miR-199a-3p) in COF compared to normal bone. Eighteen common target genes were predicted, and the leader genes approach identified the following genes involved in human COF: EZH2, XIAP, MET and TGFBR1. According to the biology of bone and COF, the most relevant KEGG pathways revealed by enrichment analysis were proteoglycans in cancer, miRNAs in cancer, pathways in cancer, p53-, PI3K-Akt-, FoxO- and TGF-beta signalling pathways, which were previously found to be differentially regulated in bone neoplasms, odontogenic tumours and osteogenesis. CONCLUSION: miRNA dysregulation occurs in COF, and EZH2, XIAP, MET and TGFBR1 are potential targets for functional analysis validation.
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Neoplasias Óseas/genética , Neoplasias Óseas/metabolismo , Fibroma Osificante/genética , Fibroma Osificante/metabolismo , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Redes Reguladoras de Genes , MicroARNs/genética , Adolescente , Adulto , Biología Computacional , Regulación hacia Abajo , Proteína Potenciadora del Homólogo Zeste 2/genética , Femenino , Factores de Transcripción Forkhead/metabolismo , Estudios de Asociación Genética , Humanos , Masculino , MicroARNs/clasificación , Persona de Mediana Edad , Proteínas de Neoplasias/metabolismo , Tumores Odontogénicos , Osteogénesis , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Proteínas Proto-Oncogénicas c-met/genética , ARN no Traducido , Receptor Tipo I de Factor de Crecimiento Transformador beta , Receptores de Factores de Crecimiento Transformadores beta/genética , Proteína p53 Supresora de Tumor/metabolismo , Regulación hacia Arriba , Proteína Inhibidora de la Apoptosis Ligada a X/genética , Adulto JovenRESUMEN
Introduction Neoadjuvant chemotherapy (NAC) is the standard treatment for locally advanced breast cancer. However, some tumors will not respond to this treatment due to histological and molecular features. The protein EZH2 (enhancer of zest homolog 2) is a histone methyltransferase that is correlated with poorly differentiated breast carcinomas and aggressive tumor behavior. Purpose The present study evaluated the association between EZH2 expression and response to NAC, and its correlation with HER2 overexpression, estrogen and progesterone receptors (ER, PR) and Ki-67 proliferation index. Methods A total of 60 patients with locally advanced breast cancer treated with NAC were selected for this study. Twenty-three paraffin blocks had not enough material for tissue resection, and were not evaluated. A tissue microarray based in immunohistochemistry (IHC) analysis of EZH2 was performed for the remaining 37 specimens. Patients were divided into two groups based on response to NAC. Results EZH2 expression was significantly associated with markers of poor prognosis such as ER negativity (p = 0.001), PR negativity (p = 0.042) and high Ki-67 proliferation index (p = 0.002). High EZH2 expression was not correlated with the response to NAC. Conclusions Our data suggested that EZH2 protein expression may not correlate with the clinical response to NAC. Other studies with more patients are needed to confirm this observation.
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Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Proteína Potenciadora del Homólogo Zeste 2/genética , Neoplasias de la Mama/patología , Estudios de Casos y Controles , Quimioterapia Adyuvante , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Persona de Mediana Edad , Terapia Neoadyuvante , Estadificación de Neoplasias , Proyectos Piloto , Resultado del TratamientoRESUMEN
We investigated the expression and clinical implications of enhancer of Zeste homolog 2 (EZH2) and p53 protein in cervical squamous cell carcinoma (SCC) and precancerous lesions. EZH2 and p53 expressions in SCC (168), cervical intraepithelial neoplasia (CIN)-I (19), CIN-II (35), and normal tissues (30) were detected by streptavidin-peroxidase-conjugation. The correlation between co-expression of EZH2 and p53 protein and the clinic pathological features and prognosis of SCC were discussed. The positive expression rates of EZH2 and p53 were 6.7, 37.0, and 75.6%, and 3.3, 21.1, and 39.3% in normal cervical tissues, CIN, and SCC, respectively, which were significantly different (P < 0.05). The positive expression rate of EZH2 and p53 protein in SCC patients with and without lymph node metastasis was 82.9 and 70.4% (EZH2) and 45.7 and 34.7% (p53), respectively, which was also a significant difference (P < 0.05). The progression-free survival (PFS) rates in followed-up patients (N = 143) who were EZH2- and p53-negative, EZH2- or p53-positive, and EZH2- and p53-positive were 71.3 ± 1.9, 66.1 ± 2.0, and 51.3 ± 3.8 months, respectively, which was a significant difference (P < 0.001); the overall survival among these groups was 72.9 ± 1.1, 68.6 ± 1.8, and 57.4 ± 3.4 months, respectively (P < 0.001). Multivariate analyses revealed that EZH2 expression, lymph node metastasis, and tumor staging were independent prognostic factors of SCC. EZH2 and p53, which affect lymph node metastasis and prognosis of SCC, may play a key role in the occurrence and development of SCC.
Asunto(s)
Carcinoma de Células Escamosas/metabolismo , Proteína Potenciadora del Homólogo Zeste 2/biosíntesis , Proteína p53 Supresora de Tumor/biosíntesis , Displasia del Cuello del Útero/metabolismo , Neoplasias del Cuello Uterino/metabolismo , Adulto , Biomarcadores de Tumor/biosíntesis , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patología , Supervivencia sin Enfermedad , Proteína Potenciadora del Homólogo Zeste 2/genética , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Femenino , Humanos , Persona de Mediana Edad , Pronóstico , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Neoplasias del Cuello Uterino/genética , Neoplasias del Cuello Uterino/patología , Displasia del Cuello del Útero/genética , Displasia del Cuello del Útero/patologíaRESUMEN
Abstract Introduction Neoadjuvant chemotherapy (NAC) is the standard treatment for locally advanced breast cancer. However, some tumors will not respond to this treatment due to histological and molecular features. The protein EZH2 (enhancer of zest homolog 2) is a histone methyltransferase that is correlated with poorly differentiated breast carcinomas and aggressive tumor behavior. Purpose The present study evaluated the association between EZH2 expression and response to NAC, and its correlation with HER2 overexpression, estrogen and progesterone receptors (ER, PR) and Ki-67 proliferation index. Methods A total of 60 patients with locally advanced breast cancer treated with NAC were selected for this study. Twenty-three paraffin blocks had not enough material for tissue resection, and were not evaluated. A tissue microarray based in immunohistochemistry (IHC) analysis of EZH2 was performed for the remaining 37 specimens. Patients were divided into two groups based on response to NAC. Results EZH2 expression was significantly associated with markers of poor prognosis such as ER negativity (p = 0.001), PR negativity (p = 0.042) and high Ki-67 proliferation index (p = 0.002). High EZH2 expression was not correlated with the response to NAC. Conclusions Our data suggested that EZH2 protein expression may not correlate with the clinical response to NAC. Other studies with more patients are needed to confirm this observation.
Resumo Introdução A quimioterapia neoadjuvante é o tratamento padrão para os cânceres de mama localmente avançados. Entretanto, apenas uma porcentagem desses tumores irá responder ao tratamento, devido a características histológicas e moleculares. A proteína EZH2 (enhancer of zest homolog 2) é uma histona metiltransferase associada a tumores mal diferenciados e de comportamento agressivo. Objetivo O presente estudo teve como objetivo avaliar a associação entre a expressão da proteína EZH2 e a resposta à quimioterapia neoadjuvante, além da correlação dessa proteína com hiper-expressão de HER2, receptores de estrogênio e progesterona, e o marcador de proliferação Ki-67. Métodos Um total de 60 pacientes com câncer de mama localmente avançado tratadas com quimioterapia neoadjuvante foram selecionadas para esse estudo. Vinte e três blocos de parafina não continham material suficiente para ressecção e não foram avaliados. Foi realizado microarray baseado em análise imuno-histoquímica da proteína EZH2 para as 36 pacientes restantes. As pacientes foram divididas em dois grupos baseado na resposta à quimioterapia neoadjuvante. Resultados A expressão da proteína EZH2 foi significativamente associada com marcadores de pior prognóstico, como negatividade para receptor de estrogênio (p = 0,001) e progesterona (p = 0,042), além de alto Ki-67 (p = 0,002). Entretanto, a alta expressão da EZH2 não se correlacionou com a resposta à quimioterapia neoadjuvante. Conclusões Nossos dados sugerem que a expressão da proteína EZH2 pode não estar relacionada com a resposta clínica à quimioterapia neoadjuvante. Outros estudos com maior número de pacientes são necessários para confirmar esses achados.