KDM4A promotes the migration and invasion of breast cancer cell line MDA-MB-231 by downregulating BMP9 / 中国癌症杂志

Background and purpose:Exogenous bone morphogenetic protein 9(BMP9)inhibits the malignant progression of human breast cancer,but its expression is often abnormally low in breast cancer.In this study,we intended to explore the expression and role of epigenetically-modified histone lysine-specific demethylase 4A(KDM4A)in breast cancer,and to investigate the relationship between KDM4A and BMP9 and its possible regulatory mechanism.Methods:The expression of KDM4A in breast cancer and its relationship with BMP9 were analyzed by bioinformatics and verified by real-time fluorescence quantitative polymerase chain reaction(RTFQ-PCR)and Western blot.Chromatin immunoprecipitation(ChIP)verified the regulatory role of KDM4A on BMP9,and RNA stability experiments and CHX protein stability experiments verified the effect of KDM4A in BMP9 expression.Exogenous recombinant MDA-MB-231 cells transfected with KDM4A small interfering RNA(siKDM4A)or infected with siBMP9 adenovirus(Ad-siBMP9)were constructed using RNA interference technology and adenoviruses knocking down BMP9,and the migratory and invasive abilities of the cells were detected by scratch healing assay and transwell assay,respectively.Results:Bioinformatics analysis showed that the expression of KDM4A was significantly higher in breast cancer than in normal tissues,and there was a negative correlation between the expression of KDM4A and that of BMP9 in breast cancer;RTFQ-PCR and Western blot showed that KDM4A was highly expressed in different breast cancer cell lines,and the knockdown of KDM4A significantly up-regulated BMP9.ChIP experiment confirmed that KDM4A could be significantly enriched in the promoter region of BMP9 gene,reducing its histone lysine 36 position instead of position 4 methyl status,thus silencing the expression of BMP9.RNA stability assay and CHX protein stability assay confirmed that KDM4A had no significant effect on the mRNA of BMP9,but could affect its protein degradation.After knocking down KDM4A,the migration and invasion abilities of breast cancer cells MDA-MB-231 were significantly inhibited,and this effect could be partially reversed by knocking down BMP9.Conclusion:KDM4A is highly expressed in breast cancer and breast cancer cell MDA-MB-231,and can silence its expression by down-regulating the level of histone methylation in the promoter region of the BMP9 gene,as well as affecting the stability of BMP9 at the protein level rather than at the level of mRNA,and promoting the migration and invasion of breast cancer.

Clinical applications of abnormal DNA methylation in chronic myeloid leukemia / 中南大学学报(医学版)

DNA methylation,a crucial biochemical process within the human body,fundamentally alters gene expression without modifying the DNA sequence,resulting in stable changes.The changes in DNA methylation are closely related to numerous biological processes including cellular proliferation and differentiation,embryonic development,and the occurrence of immune diseases and tumor.Specifically,abnormal DNA methylation plays a crucial role in the formation,progression,and prognosis of chronic myeloid leukemia(CML).Moreover,DNA methylation offers substantial potential for diagnosing and treating CML.Accordingly,understanding the precise mechanism of DNA methylation,particularly abnormal changes in the methylation of specific genes in CML,can potentially promote the development of novel targeted therapeutic strategies.Such strategies could transform into clinical practice,effectively aiding diagnosis and treatment of CML patients.

Research progress on histone acetylation/methylation in oral diseases / 口腔疾病防治

@#Histone acetylation and methylation can affect chromatin conformation and regulate a variety of biological activities. Abnormal histone acetylation and methylation modifications are related to the occurrence and development of a variety of oral diseases. Histone acetylation and methylation increase or decrease in an orderly manner to regulate the development of teeth. Fluoride ions can destroy the balance between histone acetylation and methylation, which may be related to the occurrence of dental fluorosis. In addition, histone acetylation and methylation are involved in the regulation of oral inflammatory diseases. In the inflammatory microenvironment, the expression of histone acetyltransferase GCN5 decreases, and the expression of Dickkopf 1 (DKK1) decreases, activating the Wnt/β-catenin pathway and ultimately inhibiting the osteogenic differentiation of periodontal ligament stem cells. Enhancer of zeste homolog 2 (EZH2) and H3K27me3 levels were decreased in inflamed dental pulp tissues and cells. EZH2 inhibition inhibited the expression of interleukin (IL)-1b, IL-6 and IL-8 in human dental pulp cells under inflammatory stimulation. Histone acetylation/methylation modifications can interact with multiple signaling pathways to promote the occurrence and development of oral tumors and are related to the high invasiveness of salivary gland tumors. Small molecule drugs targeting histone acetylation and methylation-related enzymes can regulate the level of histone methylation/acetylation and have shown potential in the treatment of oral and maxillofacial diseases. For example, the histone deacetylase inhibitor vorinostat can inhibit the secretion of inflammation-related cytokines; it also promotes the maturation of odontoblasts and the formation of dentin-related matrix, demonstrating its potential in pulp preservation. Understanding the role of histone acetylation/methylation modifications in the occurrence and development of oral diseases will help promote research on epigenetic modifications in oral diseases and provide new perspectives for disease diagnosis and treatment.

Prognostic predictive value of detecting minimal residual disease in acute myeloid leukemia after 2 courses of hypomethylating agents combined with low-dose induction chemotherapy / 白血病·淋巴瘤

Objective:To explore the prognostic predictive value of detecting minimal residual disease (MRD) after 2 courses of hypomethylating agents (HMA) combined with low-dose induction chemotherapy in patients with acute myeloid leukemia (AML).Methods:The data of 43 newly diagnosed AML patients treated by HMA combined with low-dose induction chemotherapy in Jingjiang People's Hospital of Jiangsu Province from January 2016 to January 2021 were retrospectively analyzed, and the bone marrow MRD levels were detected by multiparametric 10-color flow cytometry (MFC) after 1 course and 2 courses of chemotherapy. Patients were divided into three groups according to MRD levels: the group with negative MRD after 1 course of induction chemotherapy (MRD-1 group), the group with negative MRD after 2 courses of induction chemotherapy (MRD-2 group), and the group without negative MRD after 2 courses of induction chemotherapy (MRD+ group). Kaplan-Meier method was used to draw the progression-free survival (PFS) and overall survival (OS) curves of all patients and each group, and log-rank test was performed to compare them; the influencing factors for OS were analyzed using univariate and multivariate Cox proportional hazards models.Results:Among the 43 patients, 17 patients (39.5%) were in the MRD-1 group, 14 patients (32.6%) were in the MRD-2 group, and 12 patients (27.9%) were in the MRD+ group. There were no statistical differences among the 3 groups in gender, age, hemoglobin level at initial diagnosis, white blood cell count, platelet count, lactate dehydrogenase level, disease subtype, WT1 expression, karyotype, and genetic risk stratification (all P > 0.05). The median follow-up was 15 months (1-67 months). Survival analysis showed a median OS time of 21 months (95% CI 15 months -not reached) in 43 patients and a median PFS time of 12 months (95% CI 9-18 months) in 29 patients included in the PFS analysis; PFS and OS in the MRD-1 and MRD-2 groups were better than those in the MRD+ group (all P < 0.01), and the differences in PFS and OS between the MRD-1 and MRD-2 groups were not statistically significant (both P > 0.05); the median PFS time was 5 months (95% CI 2 months-not reached) in the MRD+ group, the median PFS time was 15 months (95% CI 7 months-not reached) in the MRD-1 group, and the median PFS time was 18 months (95% CI 11 months-not reached) in the MRD-2 group; the median OS time in the MRD+ group was 9 months (95% CI 7 months-not reached), the median OS time was not reached in the MRD-1 group, and the median OS time was 38 months (95% CI 38 months-not reached) in the MRD-2 group. Multivariate Cox regression analysis showed that age ( HR = 1.080, 95% CI 1.004-1.160, P = 0.038), MRD status (MRD-1 vs. MRD+: HR = 0.125, 95% CI 0.031-0.507, P = 0.004; MRD-2 vs. MRD+: HR = 0.146, 95% CI 0.037-0.577, P = 0.006) were independent influencing factors for OS in AML patients. Conclusions:The survival is good in AML patients with MRD negative conversion after both 1 course and 2 courses of HMA combined with low-dose induction chemotherapy, and both are better than that in patients with positive MRD after 2 courses of chemotherapy.

Research Progress of DNA Methylation in Cisplatin Resistance in Lung Cancer / 中国肺癌杂志

As one of the most common malignant tumors, lung cancer poses a serious threat to human life and health. The platinum-based drug cisplatin (DDP) is used as the first-line treatment for lung cancer. The poor prognosis of lung cancer is mostly due to developed resistance to cisplatin, which poses a serious treatment challenge. The mechanism of cisplatin resistance is complex and unclear. Numerous studies have shown that DNA methylation plays a crucial role in the emergence of lung cancer cisplatin resistance. DNA hypermethylation results in the deactivation of numerous drug resistance genes and tumor suppressor genes through a change in chromatin conformation. Finding new therapeutic targets and indicators to predict the therapeutic effect can be aided by elucidating the complex mechanism. In order to discover novel strategies to overcome cisplatin resistance in lung cancer, this paper discusses DNA methylation-mediated cisplatin resistance and offers an overview of current demethylation procedures.
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Prevention and treatment of high-risk acute myeloid leukemia recurrence after allogeneic hematopoietic stem cell transplantation / 器官移植

Acute myeloid leukemia (AML) is a group of highly-heterogeneous clonal diseases. Chemotherapy and hematopoietic stem cell transplantation are considered as effective treatment for AML. For high-risk AML patients, allogeneic hematopoietic stem cell transplantation is an effective therapeutic option. However, some AML patients may still face the problem of disease recurrence after hematopoietic stem cell transplantation. A majority of recurrent patients cannot be effectively treated by chemotherapy or secondary transplantation, which is the main cause of death after allogeneic hematopoietic stem cell transplantation. Therefore, it is of significance to strengthen follow-up of AML patients after allogeneic hematopoietic stem cell transplantation and implement appropriate measures to prevent postoperative recurrence. In this article, the monitoring, drug prevention and cell therapy of recurrence after allogeneic hematopoietic stem cell transplantation in high-risk AML patients were reviewed, aiming to provide reference for improving clinical prognosis of high-risk AML patients undergoing allogeneic hematopoietic stem cell transplantation.

Multicenter Prospective Study of Different Induction Regimens of Azacytidine in Treatment of Elderly Patients with Acute Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To observe the efficacy and safety of different induction regimens of same total dosage of azacitidine (Aza), including standard dose (standard dose group) and low-dose long-term (adjusted dose group), in the treatment of elderly acute myeloid leukemia (AML).@*METHODS@#A total of 103 elderly patients with AML (non-acute promyelocytic leukemia) from January 2020 to June 2021 were enrolled. Aza was administered at the standard dose of 75 mg/(m2·d) for 7 days in the standard dose group (50 cases), while at 100 mg/d for 7-12 days in the adjusted dose group (53 cases). The administration days in adjusted dose group was calculated based on the total standard dose of the patient's single course of treatment. The efficacy and safety between standard dose group and adjusted dose group were compared. Subgroup analysis were performed in the two groups for Aza alone, Aza combined with BCL-2 inhibitor, and Aza combined with low-dose chemotherapy for efficacy and safety.@*RESULTS@#There were no significant differences in overall response rate (ORR), incidence of adverse reaction, and 1-year overall survival (OS) rate between standard dose group and adjusted dose group (P >0.05). The ORR of combination was higher than that of Aza alone (P < 0.05), while there was no significant difference in ORR between Aza combined with BCL-2 inhibitor and Aza combined with low-dose chemotherapy (P >0.05). The combination of BCL-2 inhibitor did not increase the incidence of adverse reactions compared wtih Aza alone. There was a higher risk of myelosuppression and pulmonary infection with a combination of low-dose chemotherapy than with a combination of BCL-2 inhibitor and Aza alone (P <0.05). No significant difference was observed in 1-year OS between Aza alone, Aza combined with BCL-2 inhibitor, and Aza combined with low-dose chemotherapy (P >0.05).@*CONCLUSIONS@#Both two induction regimens can be used in elderly AML patients who cannot tolerate intensive chemotherapy with similar overall effectiveness and safety. Aza combined with low-dose chemotherapy may result in increased ORR and an increased incidence of serious adverse reactions, and may not result in longer survival compared with Aza alone. Aza combined with BCL-2 inhibitor not only has similar effect in complete remission, objective response rate, and OS compared with Aza combined with low-dose chemotherapy, but also has higher safety.

Macrophage-camouflaged epigenetic nanoinducers enhance chemoimmunotherapy in triple negative breast cancer

Chemoimmunotherapy has been approved as standard treatment for triple-negative breast cancer (TNBC), but the clinical outcomes remain unsatisfied. Abnormal epigenetic regulation is associated with acquired drug resistance and T cell exhaustion, which is a critical factor for the poor response to chemoimmunotherapy in TNBC. Herein, macrophage-camouflaged nanoinducers co-loaded with paclitaxel (PTX) and decitabine (DAC) (P/D-mMSNs) were prepared in combination with PD-1 blockade therapy, hoping to improve the efficacy of chemoimmunotherapy through the demethylation of tumor tissue. Camouflage of macrophage vesicle confers P/D-mMSNs with tumor-homing properties. First, DAC can achieve demethylation of tumor tissue and enhance the sensitivity of tumor cells to PTX. Subsequently, PTX induces immunogenic death of tumor cells, promotes phagocytosis of dead cells by dendritic cells, and recruits cytotoxic T cells to infiltrate tumors. Finally, DAC reverses T cell depletion and facilitates immune checkpoint blockade therapy. P/D-mMSNs may be a promising candidate for future drug delivery design and cancer combination therapy in TNBC.

Levels of base excision repair proteins in CD4+ T cells in patients with systemic lupus erythematosus / 中南大学学报(医学版)

OBJECTIVES@#Systemic lupus erythematosus (SLE) is a multi-systemic disease with the unknown pathogenic mechanism. DNA demethylation is involved in SLE pathogenesis. Growth arrest and DNA damage inducible 45 alpha (Gadd45a) takes part in the process of DNA demethylation. Gadd45a is a DNA repair-related protein. This study aims to investigate the expressions of some proteins [including activation-induced cytidine deaminase (AID), thymine DNA glycosylase (TDG), and methyl-CpG-binding domain protein 4 (MBD4)] involving in base excision repair (BER) process in CD4+ T cells in patients with SLE, and to analyze the correlations between the above BER proteins and lupus disease.@*METHODS@#From January 2019 to September 2020, 12 SLE patients and 12 healthy controls were recruited from Second Xiangya Hospital of Central South University. Peripheral blood mononuclear cells (PBMCs) were separated by Ficoll-Hypaque density gradient centrifugation and then CD4+ T cells were isolated via positive selection using Miltenyi beads. We measured the messenger RNA (mRNA) and protein expressions of AID, TDG, and MBD4 by real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blotting, respectively.@*RESULTS@#In contrast to controls, in SLE CD4+ T cells, the mRNA and protein expressions of AID were elevated (P=0.003, P=0.022, respectively); TDG protein expression was increased (P=0.017); and MBD4 protein level was reduced (P<0.001). No visible distinctions was found in the mRNA expressions of either TDG or MBD4 between the 2 groups (both P>0.05). The mRNA and protein expressions of AID and the protein levels of TDG were positively correlated with SLE disease activity index (SLEDAI). And the mRNA and protein expressions of MBD4 were negatively correlated with SLEDAI.@*CONCLUSIONS@#In SLE CD4+ T cells, the increased expressions of AID and TDG and the decreased MBD4 expression may participate in SLE pathogenic mechanism.

Detailed resume of RNA m6A demethylases

N6-Methyladenosine (m6A) is the most abundant internal modification in eukaryotic mRNA, playing critical role in various bioprocesses. Like other epigenetic modifications, m6A modification can be catalyzed by the methyltransferase complex and erased dynamically to maintain cells homeostasis. Up to now, only two m6A demethylases have been reported, fat mass and obesity-associated protein (FTO) and alkylation protein AlkB homolog 5 (ALKBH5), involving in a wide range of mRNA biological progress, including mRNA shearing, export, metabolism and stability. Furthermore, they participate in many significantly biological signaling pathway, and contribute to the progress and development of cancer along with other diseases. In this review, we focus on the studies about structure, inhibitors development and biological function of FTO and ALKBH5.

The function and regulation of TET2 in innate immunity and inflammation

TET2, a member of ten-eleven translocation (TET) family as α-ketoglutarate- and Fe

Effects of 5-azacytidine on DNA methylation and index components in patchouliol-type Pogostemon cablin / 中国中药杂志

This study aims to explore the relationship of DNA methylation with the contents of the index components as well as the growth and development of Pogostemon cablin. The demethylation reagent 5-azacytidine(5-azaC) was used to treat the tissue culture seedlings of patchouliol-type P. cablin. High performance liquid chromatography was employed to evaluate the changes of DNA methy-lation in P. cablin, and GC-MS to detect the contents of index components in P.cablin. The agronomic characters of P.cablin were measured using the common methods. The results showcased that DNA methylation of P.cablin was significantly reduced by 5-azaC in a concentration-dependent manner. Thirty days after treatment with 5-azaC at different concentrations, the content of patchouli alcohol changed slightly; compared with that in the control group, the content of pogostone in 50 μmol·L~(-1) and 100 μmol·L~(-1) 5-azaC groups was significantly up-regulated. The 100 μmol·L~(-1) 5-azaC group had the largest differences in contents of pogostone and patchouli alcohol compared with the control group, followed by the 50 μmol·L~(-1) 5-azaC group. Ninety days after disinhibition, the content of pogostone in the treatment group was significantly increased and the content of patchouli alcohol was significantly decreased. In addition, 5-azaC significantly inhibited the growth and development of P.cablin in a dose-dependent manner. These results indicate that DNA methylation regulates the biosynthesis of the index components in patchouliol-type P.cablin and proper demethylation can directly promote the synthesis of pogostone and indirectly affect the accumulation of patchouli alcohol.

Clinical characteristics of acute myeloid leukemia patients with TET2 gene mutation and effects of TET2 mutation on therapeutic efficacy and prognosis / 白血病·淋巴瘤

Objective:To investigate clinical features of adult patients with acute myeloid leukemia (AML) with TET2 gene mutation and effects of TET2 mutation on therapeutic efficacy and prognosis.Methods:A total of 123 newly diagnosed adult AML patients (except for acute promyelocytic leukemia) admitted to Jining No.1 People's Hospital from March 2017 to April 2021 were selected. Mutations of 24 AML-related genes including TET2 mutation were detected by using second-generation sequencing technology. Patients were divided into two groups according to the presence of TET2 mutation: TET2 mutation group and TET2 wild type group. The differences in clinicopathological characteristics, short-term efficacy and survival of both groups were compared.Results:Among 123 patients, TET2 mutation was detected in 28 cases (22.8%). Compared with TET2 wild type group, the patients were older [(59±15) years vs.(49±16) years, t = 2.984, P = 0.003], French-American-British (FAB) Corporative Group M 4 and M 5 subtypes were more common [75.0% (21/28) vs. 51.6% (49/95), χ2 = 4.838, P = 0.028], and the positive rate of CD34 in AML patients was lower in TET2 mutation group [46.4% (13/28) vs.72.6% (69/95), χ2 = 6.685, P = 0.010]. Moreover, TET2 mutation was more likely to be accompanied with ZRSR2 mutation [10.7% (3/28) vs. 1.1% (1/95), P = 0.037] and NPM1 mutation [35.7% (10/28) vs.17.9% (17/95), χ2 = 4.008, P = 0.045], but less likely to be accompanied with IDH1/2 mutation [0 vs.17.9% (17/95), P = 0.012]. However, there were no statistically significant differences in gender, peripheral blood leukocyte count at initial diagnosis, hemoglobin level, platelet count, bone marrow blasts ratio, cytogenetics and the European LeukemiaNet (ELN) risk stratification between the two groups (all P>0.05). In addition, there were no significant differences in the overall response rate (ORR) of 1 cycle chemotherapy [75.0% (12/16) vs. 66.7% (42/63), χ2 = 0.410, P = 0.522] and demethylation therapy [66.7% (4/6) vs. 44.4% (8/18), P = 0.640]. The difference in overall survival (OS) of both groups was not statistically significant [median OS time: 23 months (95% CI 5-41 months) vs. 35 months (95% CI 18-52 months, P = 0.498]. Conclusions:In AML patients, TET2 mutation is associated with advanced age, M 4 and M 5 subtypes, and low expression of CD34 on AML blasts. TET2 mutation is commonly accompanied by ZRSR2 and NPM1 mutation, but not IDH1 or IDH2 mutation. TET2 mutation may have no significant effects on therapeutic efficacy and survival in the whole cohort of AML patients without risk stratification.

Effects of different treatment regimens before allogeneic-hematopoietic stem cell transplantation on the outcome after transplantation of patients with myelodysplastic syndrome: a meta analysis / 白血病·淋巴瘤

Objective:To systematically evaluate effects of different treatment schemes before allogeneic-hematopoietic stem cell transplantation (allo-HSCT) on the long-term relapse and survival of patients with myelodysplastic syndrome (MDS) after transplantation.Methods:The related literatures were searched from databases of Ovid, Cochrane Library, PubMed, Embase, CNKI, VIP, WanFang and CBM from inception to December 2019. And then 2 reviewers independently extracted data, assessed methodological quality and crosschecked on the included literatures. According to the treatment methods, the cases included in the literatures were divided into demethylation drug (decitabine or azacytidine) treatment (demethylation treatment group) and traditional treatment regimen (including chemotherapy and support treatment) (traditional treatment group). RevMan 5.3 software was used to analyze overall survival (OS), recurrence, non-relapse mortality (NRM) and relapse free survival (RFS).Results:Finally, 10 articles were included. The results of meta-analysis showed that in the traditional treatment group, the differences of 3-year OS rate [44.6% (146/327) vs. 35.5%(138/389); OR = 0.93, 95% CI 0.38-2.27, P = 0.87], the recurrence rate [32.4% (106/327) vs. 37.3% (145/389); OR = 1.00, 95% CI 0.49-2.05, P = 0.99], NRM [26.3% (86/327) vs. 27.0% (105/389); OR = 1.05, 95% CI 0.75-1.49, P = 0.77], RFS rate [9.2% (30/327) vs. 12.6% (49/389); OR = 0.74, 95% CI 0.26-2.10, P = 0.57] between the chemotherapy group and the support treatment group were not statistically significant. The differences of 3-year OS rate [40.7% (165/405) vs. 45.9% (290/632); OR = 0.98, 95% CI 0.71-1.36, P = 0.28], recurrence rate [32.6% (132/405) vs. 38.3% (242/632); OR = 1.05, 95% CI 0.79-2.05, P = 0.25], NRM [27.2% (110/405) vs. 24.8% (157/632); OR = 0.81, 95% CI 0.59-1.11, P = 0.68], RFS rate [46.7% (189/405) vs. 42.2 (267/632); OR = 0.84, 95% CI 0.63-1.12, P = 0.85] between demethylation treatment group and traditional treatment group were not statistically significant. There were no significant differences in 3-year OS rate, recurrence rate, NRM and RFS rate between demethylation treatment group and chemotherapy group, demethylation treatment group and support treatment group (all P > 0.05). Conclusion:Different treatment regimens before allo-HSCT have no significant effect on survival or recurrence after transplantation for patients with MDS.

Role of DNA dioxygenase TET1 in cardiac fibrosis induced by high pressure / 中国药理学通报

Aim To investigate the mechanism of TET1 in cardiac fibrosis induced by high pressure. Methods Wistar rats and spontaneous hypertension rats(SHR) were selected to detected the expression of TET1, TGF-β, COL-1 and COL-3 in myocardium by Western blot; HE and Masson staining were used to detect myocardial pathological changes. Neonatal rat cardiac fibroblasts (NRCFs) were isolated from the ventricles of neonatal Sprague-Dawley rats and stimulated by 0 mm-Hg, 120 mmHg and 180 mmHg high pressure. Immunofluorescence was used to detect the changes of 5-hmC in the NRCFs. The changes of 5-hmC and 5-mC in TGF-β promoter region were detected by qRT-PCR. The expressions of TET1, TGF-β, COL-1 and COL-3 were detected by Western blot. Results Compared with Wistar rats, SHR showed increased blood pressure, increased fibrous collagen in ventricular tissues, and significantly increased expressions of TET1, TGF-P, COL-1 and COL-3. Compared with the 0 mmHg group, 120 mmHg and 180 mmHg group significantly induced the increase of TET1, 5-hmC, TGF-p, COL-1 and COL-3. TET1 knockdown significantly reduced the increase of 5-hmC, TGF-β, COL-1 and COL-3 under 180 mmHg pressure. Besides, knockdown TET1 significantly reduced the level of 5-hmC and increased the level of 5-mC and 5-hmC in the TGF-β promoter region. Conclusions High pressure induced cardiac fibrosis is associated with the promotion of TGF-β promoter demethylation and the increased of TGF-β expression by TET1.

Expression and characterization of a novel cytochrome P450 enzyme from Variovorax paradoxus S110 / 生物工程学报

Cytochrome P450 monooxygenases as powerful biocatalysts catalyze a wide range of chemical reactions to facilitate exogenous substances metabolism and biosynthesis of natural products. In order to explore new catalytic reactions and increase the number of P450 biocatalysts used in synthetic biology, a new self-sufficient cytochrome P450 monooxygenase (P450(VpMO)), belongs to CYP116B class, was mined from Variovorax paradoxus S110 genome and expressed in Escherichia coli. Based on characterization of the enzymatic properties, it shows that the optimal pH and temperature for P450(VpMO) reaction activity are 8.0 and 45 °C, respectively. P450(VpMO) is relatively stable at temperatures below 35 °C. The Km and kcat of P450(VpMO) toward 4-Methoxyacetophenone are 0.458 mmol/L and 2.438 min⁻¹, respectively. Importantly, P450(VpMO) was able to catalyze the demethylation reaction for a range of substrates containing methoxy group. Its demethylation reactivity is reasonably better than other P450s belongs to CYP116B class, particularly, for 4-methoxyacetophenone with a great conversion efficiency at 91%, showing that P450(VpMO) could be used as a great biocatalyst candidate for further analysis.

Research progress of histone lysine demethylase KDM5A in tumors / 肿瘤

Histone methylation is one of the important research contents of epigenetics. Methylation of histones is dynamically regulated by histone methylase and histone demethylase. Histone lysine (K) demethylase 5A (KDM5A) is an important member in the histone demethylase family, which can specifically remove the dimethyl and trimethyl from the 4th lysine of histone H3 (H3K4me2/3), thus mediating gene silencing and regulating cell function. KDM5A can directly or indirectly maintain tumor cell dryness, inhibit cell metabolism and differentiation, promote tumor cell proliferation, metastasis and drug resistance, so it is closely related to the occurrence, development and drug resistance of various tumors. KDM5A may become a new potential target for the diagnosis and treatment of tumors.

Effect of Qinghuang Powder () Combined with Bupi Yishen Decoction () in Treating Patients with Refractory Cytopenia with Multilineage Dysplasia through Regulating DNA Methylation / 中国结合医学杂志

OBJECTIVE@#To explore the effect of Qinghuang Powder (QHP,()combined with Bupi Yishen Decoction (BPYS, ) on myelodysplastic syndromes (MDS) patients with refractory cytopenia with multilineage dysplasia (RCMD) and determine the change of DNA methylation in MDS-RCMD patients after the treatment of Chinese medicine formula.@*METHODS@#All 308 MDS-RCMD patients were treated with QHP combined with BPYS for 2 months at least, absolute neutrophil count (ANC), hemoglobin (Hb), platelets (PLT), primitive bone marrow cells and chromosome karyotype were chosen as the main evaluation indexes to analyze the treatment effect according to criteria from the MDS International Working Group. Then 43 bone marrow samples from 15 MDS-RCMD patients and 28 healthy donors were obtained for the examination of DNA methylation. Gene Ontology (GO) and Pathway analysis were applied to analyze the methylation data.@*RESULTS@#The overall MDS response rate to QHP was 61.68% (190/360) including hematologic improvement-neutrophil (HI-N) or hematologic improvement-erythroid (HI-E) or hematologic improvement-platelet (HI-P). Patients with anemia had a better response rate than patients with neutropenia or thrombocypenia (55.88% vs 31.54% or 55.88% vs. 36.9%). The DNA methylation microarray analysis disclosed that 4,257 hypermethylated genes were demethylated upon the treatment with QHP and BPYS. GO analysis and Pathway analysis showed that these demethylated genes were involved in a lot of tumor-related pathways and functions.@*CONCLUSIONS@#QHP combined with BPYS could effectively treat MDS-RCMD patients through hematologic improvement (HI-N, HI-P or HI-E) and PLT and RBC transfusion independence due to the demethylation, thereby providing another choice for the treatment of patients with MDS-RCMD.

Role of TET3-induced DNA demethylation in methane-induced up-regulation of Nrf2 expression in rat spinal cord neurons subjected to oxygen-glucose deprivation and restoration injury / 中华麻醉学杂志

Objective To evaluate the role of TET3-induced DNA demethylation in methane-in-duced up-regulation of nuclear factor-erythroid 2-related factor 2 ( Nrf2) expression in rat spinal cord neu-rons subjected to oxygen-glucose deprivation and restoration ( OGD∕R) injury. Methods The primarily cultured spinal cord neurons of rats were seeded in 6-well plates at a density of 1×105 cells∕ml and divided into 5 groups ( n=48 each) using a random number table method: control group ( group C) , group OGD∕R, methane group (group M), methane plus TET3-siRNA group (group M+siTET3) and methane plus negative siRNA group (group M+siCon). The medium was replaced with glucose- and serum-free Earle's salt solution, and the neurons were exposed to 5％ CO2-95％N2 in an incubator for 2 h followed by routine culture to establish the model of OGD∕R. In group M, 200μl methane-saturated saline ( final concentration of methane 1. 8 mmol∕L) was added at oxygen-glucose restoration. TET3-siRNA 100 pmol∕L and negative siRNA 100 pmol∕L were added at 24 h before oxygen-glucose restoration to perform transfection in M+siTET3 and M+siCon groups, respectively. At 12 h of oxygen-glucose restoration, the neuronal survival rate, release rate of lactic dehydrogenase ( LDH) and apoptotic rate of neurons were measured, and the ex-pression of TET3 and Nrf2 protein and mRNA was detected by Western blot and fluorescent quantitative re-al-time polymerase chain reaction, respectively, and contents of superoxide dismutase (SOD), catalase ( CAT) and malonaldehyde ( MDA) were measured by enzyme-linked immunosorbent assay. Neuronal DNA was extracted for determination of methylation and hydroxymethylation rates of DNA ( by enzyme-linked im-munosorbent assay) and methylation of CpG island in Nrf2 gene promoter ( by fluorescent real-time methyla-tion specific polymerase chain reaction). Results Compared with group C, the survival rate of neurons was significantly decreased, the release rate of LDH and apoptotic rate were increased in group OGD∕R ( P<0. 01) . Compared with OGD∕R, the survival rate of neurons was significantly increased, the release rate of LDH and apoptotic rate were decreased, the expression of TET3 and Nrf2 protein and mRNA was up-regula-ted, DNA hydroxymethylation rate and contents of SOD and CAT were increased, and the DNA and Nrf2 promoter methylation rates and MDA content were decreased in group M ( P<0. 05 or 0. 01) . Compared with group M, the neuronal survival rate was significantly decreased, the release rate of LDH and apoptotic rate were increased, the expression of TET3 and Nrf2 protein and mRNA was down-regulated, the DNA hydroxymethylation rate and contents of SOD and CAT were decreased, and the DNA and Nrf2 promoter methylation rates and MDA content were increased in group M+siTET3 ( P<0. 05 or 0. 01) , and no signifi-cant change was found in the parameters mentioned above in group M+siCon ( P>0. 05) . Conclusion The mechanism by which methane up-regulates Nrf2 expression in rat spinal cord neurons subjected to OGD∕R injury is related to activating TET3 and promoting DNA demethylation in Nrf2 promoter.

Effect of HPV-16 LCR internal meCpG site demethylation on HPV positive head and neck tumor cells / 中国耳鼻咽喉头颈外科

OBJECTIVE To investigate the effect of HPV-16 LCR internal meCpG site demethylation on HPV positive head and neck tumor cells. METHODS After 5-azoxy-2-deoxycytidine(5-Aza-2'-dc) demethylation treatment, the methylation status of CpG sites in the long regulatory region of UM-SCC47, CaSki and SiHa tumor cells was detected by BSP assay. The expression of HPV 16 E6 and E7 mRNA was detected by real-time PCR. The effects of 5-Aza-2'-dc on cell growth and apoptosis were detected. Using Lipolnfectamine RNAiMAX to transfect siRNA, the expression of E6 and E7 was silenced, and then the changes of biological state of cell proliferate inhibition, apoptosis and cycle were detected. RESULTS Cells treated with 5-Aza-2, -dc at a concentration of 0.5 μmol/L for 96 h had the best demethylation. After demethylation of 5-Aza-2'-dc, the expression levels of E6 and E7 mRNA in UM-SCC47 cells and CaSki cells were significantly decreased compared with the control group(t=1.356, 2.623, P=0.031, 0.005; t=1.798, 2.015, P=0.011, 0.009). The expression levels of E6 and E7 mRNA in SiHa cells were not significantly differences compared with the control group(t=1.591, 1.153, P=1.105, 0.753); After treated with 5-Aza-2'-dc, cells proliferation were significantly inhibited. After E6 and E7 expression was silenced, the growth of all three kinds of cells was inhibited. The apoptosis of all three kinds of cells were significantly increased, cells arrested in S phase and G2/M phase were significantly increased compared with the control groups, the difference were statistically significant. CONCLUSION After demethylation, the response of HPV-16 positive tumor cells with different methylation status in the long regulatory region is completely different, indicating that in the HPV-16 positive tumors, there may be some information about the methylation status in the long regulatory region Different tumor characteristics and mechanism of cancer.