Efecto de la epigenética en la artritis reumatoide / Effect of epigenetics on rheumatoid arthritis

La artritis reumatoide es una enfermedad autoinmune e inflamatoria que afecta de manera predominante a las articulaciones diartrodiales. En esta patología los factores ambientales o conductuales pueden actuar en sinergia con la predisposición genética, acelerando el inicio y la gravedad de la enfermedad. Este vínculo entre el medio ambiente y el genoma está mediado por marcas epigenéticas en el ácido desoxirribonucleico, incluyendo su metilación, la modificación de histonas y la regulación mediada por ácido ribonucleico no codificante. La epigenética puede generar cambios fenotípicos hereditarios, que no están determinados por modificaciones en la secuencia del ácido desoxirribonucleico y, en consecuencia, son reversibles. Por lo tanto la dieta, los medicamentos y otros factores ambientales, tendrían la capacidad de modularlos. La identificación de una desregulación epigenética específica, puede ofrecer una mayor comprensión de la fisiopatología de la enfermedad e influenciar positivamente en la prevención, diagnóstico y desarrollo de nuevas dianas terapéuticas.

Rheumatoid arthritis is an autoimmune and inflammatory disease that predominantly affects the diarthrodial joints. In this pathology, environmental or behavioral factors can act in synergy with genetic predisposition, accelerating the onset and severity of the disease. This link between the environment and the genome is mediated by epigenetic marks on deoxyribonucleic acid, including its methylation, histone modification, and noncoding ribonucleic acid-mediated regulation. Epigenetics can generate heritable phenotypic changes, which are not determined by modifications in the deoxyribonucleic acid sequence and are therefore reversible. Therefore, diet, medications and other environmental factors would have the ability to modulate them. The identification of a specific epigenetic dysregulation can offer a better understanding of the pathophysiology of the disease and positively influence the prevention, diagnosis and development of new therapeutic targets.

Research Progress of Role and Mechanism of SETD7 in Tumor Occurrence and Progression / 中国肺癌杂志

The occurence and development of tumors is a complicated process, which not only depends on the mutation or deletion of genes, but also is affected by epigenetic regulation. Accumulating evidences have shown that epigenetic modifications play fundamental roles in transcriptional regulation, heterochromatin formation, X chromosome inactivation, DNA damage response and tumor development. SET domain containing lysine methyltransferase 7 (SETD7) was initially identified as an important lysine methyltransferase, which methylated histone and non-histone proteins. These modifications play fundamental roles. Once this modification disorders, it can directly lead to cell abnormalities and cause many diseases. Studies have shown that SETD7 is related to the occurence and development of various tumors, but the methylation sites of SETD7 and its regulatory mechanism have not been fully elucidated. This article summarizes the research progress of the role of SETD7 on histone and non-histone methylation modification in tumors and the molecular mechanism, in order to provide new therapeutic targets for tumor pathogenesis and diagnosis.
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Knockdown of ACC1 promotes migration of esophageal cancer cell / 中华肿瘤杂志

Objective: To investigate the effect of acetyl-CoA carboxylase 1 (ACC1) knockdown on the migration of esophageal squamous cell carcinoma (ESCC) KYSE-450 cell and underlying mechanism. Methods: Lentiviral transfection was conducted to establish sh-NC control cell and ACC1 knocking down cell (sh-ACC1). Human siRNA HSP27 and control were transfected by Lipo2000 to get si-HSP27 and si-NC. The selective acetyltransferase P300/CBP inhibitor C646 was used to inhibit histone acetylation and DMSO was used as vehicle control. Transwell assay was performed to detect cell migration. The expression of HSP27 mRNA was examined by reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) and the expressions of ACC1, H3K9ac, HSP27 and epithelial-mesenchymal transition-related proteins E-cadherin and Vimentin were detected by western blot. Results: The expression level of ACC1 in sh-NC group was higher than that in sh-ACC1 group (P<0.01). The number of cell migration in sh-NC group was (159.00±24.38), lower than (361.80±26.81) in sh-ACC1 group (P<0.01). The protein expression levels of E-cadherin and Vimentin in sh-NC group were statistically significant compared with sh-AAC1 group (P<0.05). The migrated cell number in sh-NC+ si-NC group was (189.20±16.02), lower than (371.60±38.40) in sh-ACC1+ si-NC group (P<0.01). The migrated cell number in sh-NC+ si-NC group was higher than that in sh-NC+ si-HSP27 group (152.40±24.30, P<0.01), and the migrated cell number in sh-ACC1+ si-NC group was higher than that in sh-ACC1+ si-HSP27 group (P<0.01). The protein expression levels of E-cadherin and Vimentin in sh-NC+ si-NC group were significantly different from those in sh-ACC1+ si-NC and sh-NC+ si-HSP27 groups (P<0.01). The protein expression levels of E-cadherin and Vimentin in sh-ACC1+ si-NC group were significantly different from those in sh-ACC1+ si-HSP27 group (P<0.01). After 24 h treatment with C646 at 20 μmmo/L, the migrated cell number in sh-NC+ DMSO group was (190.80±11.95), lower than (395.80±17.10) in sh-ACC1+ DMSO group (P<0.01). The migrated cell number in sh-NC+ DMSO group was lower than that in sh-NC+ C646 group (256.20±23.32, P<0.01). The migrated cell number in sh-ACC1+ DMSO group was higher than that in sh-ACC1+ C646 group (87.80±11.23, P<0.01). The protein expressions of H3K9ac, HSP27, E-cadherin and Vimentin in sh-NC+ DMSO group were significantly different from those in sh-ACC1+ DMSO group and sh-NC+ C646 group (P<0.01). The protein expression levels of H3K9ac, HSP27, E-cadherin and Vimentin in sh-ACC1+ DMSO group were significantly different from those in sh-ACC1+ C646 group (P<0.01). Conclusion: Knockdown of ACC1 promotes the migration of KYSE-450 cell by up-regulating HSP27 and increasing histone acetylation.

METTL14 is a chromatin regulator independent of its RNA N6-methyladenosine methyltransferase activity

METTL3 and METTL14 are two components that form the core heterodimer of the main RNA m6A methyltransferase complex (MTC) that installs m6A. Surprisingly, depletion of METTL3 or METTL14 displayed distinct effects on stemness maintenance of mouse embryonic stem cell (mESC). While comparable global hypo-methylation in RNA m6A was observed in Mettl3 or Mettl14 knockout mESCs, respectively. Mettl14 knockout led to a globally decreased nascent RNA synthesis, whereas Mettl3 depletion resulted in transcription upregulation, suggesting that METTL14 might possess an m6A-independent role in gene regulation. We found that METTL14 colocalizes with the repressive H3K27me3 modification. Mechanistically, METTL14, but not METTL3, binds H3K27me3 and recruits KDM6B to induce H3K27me3 demethylation independent of METTL3. Depletion of METTL14 thus led to a global increase in H3K27me3 level along with a global gene suppression. The effects of METTL14 on regulation of H3K27me3 is essential for the transition from self-renewal to differentiation of mESCs. This work reveals a regulatory mechanism on heterochromatin by METTL14 in a manner distinct from METTL3 and independently of m6A, and critically impacts transcriptional regulation, stemness maintenance, and differentiation of mESCs.

The engagement of histone lysine methyltransferases with nucleosomes: structural basis, regulatory mechanisms, and therapeutic implications

Histone lysine methyltransferases (HKMTs) deposit methyl groups onto lysine residues on histones and play important roles in regulating chromatin structure and gene expression. The structures and functions of HKMTs have been extensively investigated in recent decades, significantly advancing our understanding of the dynamic regulation of histone methylation. Here, we review the recent progress in structural studies of representative HKMTs in complex with nucleosomes (H3K4, H3K27, H3K36, H3K79, and H4K20 methyltransferases), with emphasis on the molecular mechanisms of nucleosome recognition and trans-histone crosstalk by these HKMTs. These structural studies inform HKMTs' roles in tumorigenesis and provide the foundations for developing new therapeutic approaches targeting HKMTs in cancers.

Insights into epigenetic patterns in mammalian early embryos

Mammalian fertilization begins with the fusion of two specialized gametes, followed by major epigenetic remodeling leading to the formation of a totipotent embryo. During the development of the pre-implantation embryo, precise reprogramming progress is a prerequisite for avoiding developmental defects or embryonic lethality, but the underlying molecular mechanisms remain elusive. For the past few years, unprecedented breakthroughs have been made in mapping the regulatory network of dynamic epigenomes during mammalian early embryo development, taking advantage of multiple advances and innovations in low-input genome-wide chromatin analysis technologies. The aim of this review is to highlight the most recent progress in understanding the mechanisms of epigenetic remodeling during early embryogenesis in mammals, including DNA methylation, histone modifications, chromatin accessibility and 3D chromatin organization.

Pioneer of prostate cancer: past, present and the future of FOXA1

Prostate cancer is the most commonly diagnosed non-cutaneous cancers in North American men. While androgen deprivation has remained as the cornerstone of prostate cancer treatment, resistance ensues leading to lethal disease. Forkhead box A1 (FOXA1) encodes a pioneer factor that induces open chromatin conformation to allow the binding of other transcription factors. Through direct interactions with the Androgen Receptor (AR), FOXA1 helps to shape AR signaling that drives the growth and survival of normal prostate and prostate cancer cells. FOXA1 also possesses an AR-independent role of regulating epithelial-to-mesenchymal transition (EMT). In prostate cancer, mutations converge onto the coding sequence and cis-regulatory elements (CREs) of FOXA1, leading to functional alterations. In addition, FOXA1 activity in prostate cancer can be modulated post-translationally through various mechanisms such as LSD1-mediated protein demethylation. In this review, we describe the latest discoveries related to the function and regulation of FOXA1 in prostate cancer, pointing to their relevance to guide future clinical interventions.

Research progress on methylation of histones H3K9 and H3K27 in early-stage embryos / 中华医学遗传学杂志

With the in-depth exploration of all stages in early-stage embryos, in particular zygotic genome activation and first cell lineage differentiation, researchers have found that early embryonic epigenetics follows a strict pattern of temporal and spatial modification. Previous studies have determined the inhibitory effect of H3K9me3 and H3K27me3 on genomic expression, and found that they are involved in many core biological events in the genome such as chromatin reprogramming, genomic imprinting, maintenance of embryonic stem cell pluripotency and somatic cell nuclear transfer, though the detailed molecular mechanism has remained elusive. From the point of developmental biology and epigenetics, this article has expounded the research progress on the methylation of H3K9 and H3K27 histones in early-stage embryos, which may provide a clue for the complex mechanism of embryonic development and improvement of culture method for embryos in vitro.

miR-22 suppresses tumorigenesis and improves radiosensitivity of breast cancer cells by targeting Sirt1

BACKGROUND: miR-22 has been shown to be frequently downregulated and act as a tumor suppressor in multiple cancers including breast cancers. However, the role of miR-22 in regulating the radioresistance of breast cancer cells, as well as its underlying mechanism is still not well understood. METHODS: The expressions of miR-22 and sirt1 at mRNA and protein levels were examined by qRT-PCR and Western Blot. The effects of miR-22 overexpression and sirt1 knockdown on cell viability, apoptosis, radiosensitivity, γ-H2AX foci formation were evaluated by CCK-8 assay, flow cytometry, colony formation assay, and γ-H2AX foci formation assay, respectively. Luciferase reporter assay and qRT-PCR analysis were performed to confirm the interaction between miR-22 and sirt1. RESULTS: miR-22 was downregulated and sirt1 was upregulated at both mRNA and protein levels in breast cancer cells. miR-22 overexpression or sirt1 knockdown significantly suppressed viability, induced apoptosis, reduced survival fraction, and increased the number of γ-H2AX foci in breast cancer cells. Sirt1 was identified as a target of miR-22 and miR-22 negatively regulated sirt1 expression. Ectopic expression of sirt1 dramatically reversed the inhibitory effect of miR-22 on cell viability and promotive effect on apoptotic rates and radiosensitivity in breast cancer cells. CONCLUSIONS: miR-22 suppresses tumorigenesis and improves radiosensitivity of breast cancer cells by targeting sirt1, providing a promising therapeutic target for breast cancer.

Assessment of adherence to the guidelines for the management of nausea and vomiting induced by chemotherapy / Avaliação da aderência à diretriz de cuidados para náuseas e vômitos induzidos por quimioterapia

ABSTRACT Objective: To assess adherence of the prescribing physicians in a private cancer care center to the American Society of Clinical Oncology guideline for antiemetic prophylaxis, in the first cycle of antineoplastic chemotherapy. Methods: A total of 139 chemotherapy regimens, of 105 patients, were evaluated retrospectively from 2011 to 2013. Results: We observed 78% of non-adherence to the guideline rate. The main disagreements with the directive were the prescription of higher doses of dexamethasone and excessive use of 5-HT3 antagonist for low risk emetogenic chemotherapy regimens. On univariate analysis, hematological malignancies (p=0.005), the use of two or more chemotherapy (p=0.05) and high emetogenic risk regimes (p=0.012) were factors statistically associated with greater adherence to guidelines. Treatment based on paclitaxel was the only significant risk factor for non-adherence (p=0.02). By multivariate analysis, the chemotherapy of high emetogenic risk most correlated with adherence to guideline (p=0.05). Conclusion: We concluded that the adherence to guidelines is greater if the chemotherapy regime has high emetogenic risk. Educational efforts should focus more intensely on the management of chemotherapy regimens with low and moderate emetogenic potential. Perhaps the development of a computer generated reminder may improve the adherence to guidelines. .

RESUMO Objetivo: Avaliar a adesão dos médicos prescritores, de um centro privado especializado em oncologia, à diretriz de antiêmese profilática da American Society of Clinical Oncology, no primeiro ciclo de quimioterapia antineoplásica. Métodos: Foram avaliados retrospectivamente 139 esquemas de quimioterapia, de 105 pacientes, tratados no período de 2011 a 2013. Resultados: Foram observados 78% de taxa de não adesão à diretriz. As principais discordâncias com a diretriz foram prescrição de doses mais elevadas de dexametasona e uso excessivo de antagonista 5-HT3 para regimes de quimioterapia de risco emetogênico baixo. Pela análise univariada, malignidades hematológicas (p=0,005), uso de dois ou mais quimioterápicos (p=0,05) e regimes de alto risco emetogênico (p=0,012) foram fatores estatisticamente associados a maior adesão à diretriz. O tratamento baseado em paclitaxel foi o único fator estatisticamente significativo para a não adesão (p=0,02). Pela análise multivariada, a quimioterapia de alto risco emetogênico apresentou maior correlação com a adesão à diretriz (p=0,05). Conclusão: Houve maior aderência para a quimioterapia de alto risco emetogênico. Esforços educacionais devem se concentrar mais intensamente na gestão de regimes de quimioterapia com potencial emetogênico baixo e moderado. Talvez o desenvolvimento de lembretes gerados por sistemas informatizados possa melhorar a aderência à diretriz. .

Are 30 minutes of rest between two incremental shuttle walking tests enough for cardiovascular variables and perceived exertion to return to baseline values?

Objective: To verify whether 30 minutes of rest between two incremental shuttle walking tests (ISWT) are enough for cardiovascular variables and perceived exertion to return to baseline values in healthy subjects in a broad age range. Method: The maximal exercise capacity of 334 apparently healthy subjects (age ≥18) was evaluated using the ISWT. The test was performed twice with 30 minutes of rest in between. Heart rate (HR), arterial blood pressure (ABP), dyspnea, and leg fatigue were evaluated before and after each test. Subjects were allocated to 6 groups according to their age: G1: 18-29 years; G2: 30-39 years; G3: 40-49 years; G4: 50-59 years; G5: 60-69 years and G6: ≥70 years. Results: All groups had a good performance in the ISWT (median >90% of the predicted distance). The initial HR (HRi) of the second ISWT was higher than the first ISWT in the total sample (p<0.0001), as well as in all groups (p<0.0001). No difference was observed in the behavior of ABP (systolic and diastolic) and dyspnea between the two tests, but this difference occurred for leg fatigue (greater before the second ISWT) in G1 (p<0.05). Most subjects (58%) performed better in the second test. Conclusion: 30 minutes of rest between two ISWTs are not enough for all cardiovascular variables and perceived exertion to return to baseline values. However, this period appears to be sufficient for blood pressure and performance to recover in most subjects. .

Letramento em saúde de diabéticos tipo 2: fatores associados e controle glicêmico / Health literacy in type 2 diabetics: associated factors and glycemic control

Pacientes com diabetes mellitus requerem um autocuidado extenso, com tratamentos complexos e comportamentos de saúde adequados, sendo, essas habilidades, fator chave. Frente a tal complexidade surge a importância do letramento funcional em saúde. O objetivo do estudo foi analisar fatores associados ao letramento em saúde e sua relação com controle glicêmico em pacientes diabéticos. Este estudo foi realizado com 82 pacientes diabéticos tipo 2, atendidos em um ambulatório de endocrinologia de um hospital público, de ambos os sexos e com idade entre 19 e 59 anos, que responderam à versão abreviada e traduzida do Test of Functional Health Literacy in Adults (b-TOFHLA). Valores de glicemia de jejum e hemoglobina glicada foram coletados dos prontuários dos participantes. Foram realizadas correlações, comparações de médias e modelos de regressão linear. O letramento inadequado foi encontrado em 65,9% dos pacientes. Foram fatores associados à pontuação do b-TOFHLA, a idade e os anos de estudos. O letramento global não explicou o controle glicêmico, mas o numeramento apresentou associação com tal controle. Nossos resultados apontam para a necessidade de melhorar o numeramento em saúde dos pacientes para obter seu melhor controle glicêmico, principalmente naqueles com maior idade e menos anos de estudo.

Diabetes mellitus patients must concentrate on self-care, with complex treatments and adequate health behavior in which such habits are a key factor. Due to the complexity of this issue, the importance of literacy in health arises. The goal of the study was to analyze factors associated with literacy in health and its relation with glycemic control in diabetic patients. It involved a study with 82 type 2 diabetic patients of both sexes and aged between 19 and 59 attended in the outpatient endocrinology ward of a public hospital, who filled out an abbreviated and translated version of the Test of Functional Health Literacy in Adults (b-TOFHLA). Fasting glycaemia values and glycated hemoglobin were collected from the clinical history of the participants. Correlations, mean comparisons and linear regression models were tested. Inadequate literacy in health was encountered in 65.9% of the patients. The issues involved factors associated with the b-TOFHLA point scores were age and years of schooling. Global literacy did not explain the glycemic control, but the level of numeracy presented an association with this control. The results point to the need to improve the numeracy in health of the patients to obtain enhanced glycemic control, mainly in those with more advanced age and less years of schooling.

Histone Deacetylases and Their Regulatory MicroRNAs in Hepatocarcinogenesis

A growing body of evidence suggests that epigenetic modifications are promising potential mechanisms in cancer research. Among the molecules that mediate epigenetic mechanisms, histone deacetylases (HDACs) are critical regulators of gene expression that promote formation of heterochromatin by deacetylating histone and non-histone proteins. Aberrant regulation of HDACs contributes to malignant transformation and progression in a wide variety of human cancers, including hepatocellular carcinoma (HCC), gastric cancer, lung cancer, and other cancers. Thus, the roles of HDACs have been extensively studied because of their potential as therapeutic targets. However, the underlying mechanism leading to deregulation of individual HDACs remains largely unknown. Some reports have suggested that functional microRNAs (miRNAs) modulate epigenetic effector molecules including HDACs. Here, we describe the oncogenic or tumor suppressive functions of HDAC families and their regulatory miRNAs governing HDAC expression in hepatocarcinogenesis.

ChIP-seq analysis of histone H3K9 trimethylation in peripheral blood mononuclear cells of membranous nephropathy patients

Membranous nephropathy (MN), characterized by the presence of diffuse thickening of the glomerular basement membrane and subepithelial in situ immune complex disposition, is the most common cause of idiopathic nephrotic syndrome in adults, with an incidence of 5-10 per million per year. A number of studies have confirmed the relevance of several experimental insights to the pathogenesis of human MN, but the specific biomarkers of MN have not been fully elucidated. As a result, our knowledge of the alterations in histone methylation in MN is unclear. We used chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) to analyze the variations in a methylated histone (H3K9me3) in peripheral blood mononuclear cells from 10 MN patients and 10 healthy subjects. There were 108 genes with significantly different expression in the MN patients compared with the normal controls. In MN patients, significantly increased activity was seen in 75 H3K9me3 genes, and decreased activity was seen in 33, compared with healthy subjects. Five positive genes, DiGeorge syndrome critical region gene 6 (DGCR6), sorting nexin 16 (SNX16), contactin 4 (CNTN4), baculoviral IAP repeat containing 3 (BIRC3), and baculoviral IAP repeat containing 2 (BIRC2), were selected and quantified. There were alterations of H3K9me3 in MN patients. These may be candidates to help explain pathogenesis in MN patients. Such novel findings show that H3K9me3 may be a potential biomarker or promising target for epigenetic-based MN therapies.

Histone Acetylation Level and Histone Acetyltransferase/Deacetylase Activity in Ejaculated Sperm from Normozoospermic Men

PURPOSE: The aim of this work was to evaluate nuclear histone acetylation level and total histone acetyltransferase (HAT) and deacetylase (HDAC) activity in ejaculated sperm and their relevance to conventional sperm parameters. MATERIALS AND METHODS: Thirty-three normozoospermic men were included in this study. Semen samples were processed by swim-up and then immunostained by six acetylation antibodies (H3K9ac, H3K14ac, H4K5ac, H4K8ac, H4K12ac, and H4K16ac). Our preliminary study verified the expression of HAT/HDAC1 in mature human sperm. From vitrified-warmed sperm samples, total HAT/HDAC activity was measured by commercially available kits. Nuclear DNA integrity was also measured by TUNEL assay. RESULTS: The levels of six acetylation marks were not related with conventional sperm parameters including sperm DNA fragmentation index (DFI) as well as HAT/HDAC activity. However, sperm DFI was positively correlated with HAT activity (r=0.038 after adjustment, p<0.02). HAT activity showed a negative relationship with HDAC activity (r=-0.51, p<0.01). Strict morphology was negatively correlated with acetylation enzyme index (=HAT activity/HDAC activity) (r=-0.53, p<0.01). CONCLUSION: Our works demonstrated a significant relationship of acetylation-associated enzyme activity and strict morphology or sperm DFI.

Role of histone deacetylase activity in the developing lateral line neuromast of zebrafish larvae

Histone deacetylases are involved in many biological processes and have roles in regulating cell behaviors such as cell cycle entry, cell proliferation and apoptosis. However, the effect of histone deacetylases on the development of hair cells (HCs) has not been fully elucidated. In this study, we examined the influence of histone deacetylases on the early development of neuromasts in the lateral line of zebrafish. Hair cell development was evaluated by fluorescent immunostaining in the absence or presence of histone deacetylase inhibitors. Our results suggested that pharmacological inhibition of histone deacetylases with inhibitors, including trichostatin A, valproic acid and MS-275, reduced the numbers of both HCs and supporting cells in neuromasts. We also found that the treatment of zebrafish larvae with inhibitors caused accumulation of histone acetylation and suppressed proliferation of neuromast cells. Real-time PCR results showed that the expression of both p21 and p27 mRNA was increased following trichostatin A treatment and the increase in p53 mRNA was modest under the same conditions. However, the expression of p53 mRNA was significantly increased by treatment with a high concentration of trichostatin A. A high concentration of trichostatin A also led to increased cell death in neuromasts as detected in a TUNEL assay. Moreover, the nuclei of most of these pyknotic cells were immunohistochemically positive for cleaved caspase-3. These results suggest that histone deacetylase activity is involved in lateral line development in the zebrafish and might have a role in neuromast formation by altering cell proliferation through the expression of cell cycle regulatory proteins.

Mycobacterial laminin-binding histone-like protein mediates collagen-dependent cytoadherence

When grown in the presence of exogenous collagen I, Mycobacterium bovis BCG was shown to form clumps. Scanning electron microscopy examination of these clumps revealed the presence of collagen fibres cross-linking the bacilli. Since collagen is a major constituent of the eukaryotic extracellular matrices, we assayed BCG cytoadherence in the presence of exogenous collagen I. Collagen increased the interaction of the bacilli with A549 type II pneumocytes or U937 macrophages, suggesting that BCG is able to recruit collagen to facilitate its attachment to host cells. Using an affinity chromatography approach, we have isolated a BCG collagen-binding protein corresponding to the previously described mycobacterial laminin-binding histone-like protein (LBP/Hlp), a highly conserved protein associated with the mycobacterial cell wall. Moreover, Mycobacterium leprae LBP/Hlp, a well-characterized adhesin, was also able to bind collagen I. Finally, using recombinant fragments of M. leprae LBP/Hlp, we mapped the collagen-binding activity within the C-terminal domain of the adhesin. Since this protein was already shown to be involved in the recognition of laminin and heparan sulphate-containing proteoglycans, the present observations reinforce the adhesive activities of LBP/Hlp, which can be therefore considered as a multifaceted mycobacterial adhesin, playing an important role in both leprosy and tuberculosis pathogenesis.

CpG Array Analysis of Histone H3 Lysine 4 Trimethylation by Chromatin Immunoprecipitation Linked to Microarrays Analysis in Peripheral Blood Mononuclear Cells of IgA Nephropathy Patients

PURPOSE: The purpose of the present study was to investigate the aberrance of histone H3 lysine 4 trimethylation (H3K4me3) in patients with IgA Nephropathy (IgAN). MATERIALS AND METHODS: In this study, H3K4me3 variations in peripheral blood mononuclear cells (PBMCs) from 15 IgAN patients and 15 healthy subjects were analyzed using chromatin immunoprecipitation linked to microarrays analysis (ChIP-chip). ChIP real-time PCR was used to validate the microarray results. Expression analysis by quantitative real-time PCR (qRT-PCR) revealed correlations between mRNA and H3K4me3 levels. DNA methylation status was analyzed by quantitative methylation-specific PCR. RESULTS: We found that 321 probes displayed significant H3K4me3 differences in IgAN patients compared with healthy controls. Among these probes, 154 probes displayed increased H3K4me3 and 167 probes demonstrated decreased H3K4me3. For further validation, we selected 4 key relevant genes (FCRL4, GALK2, PTPRN2 and IL1RAPL1) to study. The results of ChIP real-time PCR coincided well with the microarray data. Quantitative RT-PCR revealed the correlations between the mRNA expression and the methylation levels of H3K4me3. Different degrees of DNA methylation alterations appeared on the selected positive genes. CONCLUSION: Our studies indicated that there were significant alterations in H3K4me3 in IgAN patients. These findings may help to explain the disturbed immunity and abnormal glycosylation involved in IgAN patients.

Integrative epigenomic and genomic analysis of malignant pheochromocytoma

Epigenomic and genomic changes affect gene expression and contribute to tumor development. The histone modifications trimethylated histone H3 lysine 4 (H3K4me3) and lysine 27 (H3K27me3) are epigenetic regulators associated to active and silenced genes, respectively and alterations of these modifications have been observed in cancer. Furthermore, genomic aberrations such as DNA copy number changes are common events in tumors. Pheochromocytoma is a rare endocrine tumor of the adrenal gland that mostly occurs sporadic with unknown epigenetic/genetic cause. The majority of cases are benign. Here we aimed to combine the genome-wide profiling of H3K4me3 and H3K27me3, obtained by the ChIP-chip methodology, and DNA copy number data with global gene expression examination in a malignant pheochromocytoma sample. The integrated analysis of the tumor expression levels, in relation to normal adrenal medulla, indicated that either histone modifications or chromosomal alterations, or both, have great impact on the expression of a substantial fraction of the genes in the investigated sample. Candidate tumor suppressor genes identified with decreased expression, a H3K27me3 mark and/or in regions of deletion were for instance TGIF1, DSC3, TNFRSF10B, RASSF2, HOXA9, PTPRE and CDH11. More genes were found with increased expression, a H3K4me3 mark, and/or in regions of gain. Potential oncogenes detected among those were GNAS, INSM1, DOK5, ETV1, RET, NTRK1, IGF2, and the H3K27 trimethylase gene EZH2. Our approach to associate histone methylations and DNA copy number changes to gene expression revealed apparent impact on global gene transcription, and enabled the identification of candidate tumor genes for further exploration.

Double Strand Break of DNA in Gastric Adenoma and Adenocarcinoma / 대한소화기학회지

BACKGROUND/AIMS: DNA double strand break (DSB) is one of the critical types of DNA damage. When unrepaired DSB is accumulated in the nucleus of the cells having mutations in such genes as p53, it will lead to chromosomal instability and further more to mutation of tumor-activating genes resulting in tumorogenesis. Some of malignant cancers and its premalignant lesions were proven to have DSB in their nuclei. The aim of this study was to define the differences in expression of 53BP1 and gamma-H2AX, the markers of DSB, among normal, gastric adenoma, and gastric adenocarcinoma tissues. METHODS: Tissue microarray was made with the tissues taken from 121 patients who underwent gastrectomy for gastric adenocarcinoma, and 51 patients who underwent endoscopic mucosal resection for gastric adenoma. Immunochemical stain was performed for the marker of DSB, 53BP1 and gamma-H2AX in the tissue microarray. The normal tissues were collected from histologically confirmed tissues with no cellular atypia obtained from the patients with gastric adenocarcinoma. RESULTS: In gastric carcinoma cells, 53BP1 and gamma-H2AX were highly expressed as compared to normal epithelial cells and gastric adenoma (p<0.01). There were no differences in the expression of 53BP1 and gamma-H2AX between normal epithelium and gastric adenoma. The expression of 53BP1 in the adenoma with grade II and III atypism was more elevated than in those with grade I atypism. The expression of 53BP1 and gamma-H2AX were not significantly different according to the clinicopathologic parameters in the patients with gastric adenocarcinoma. CONCLUSIONS: The DSB in DNA seems to be associated with the development of gastric adenocarcinoma, but does not affect the premalignant adenoma cells.