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.

Long non-coding ribonucleic acid H19 and ten-eleven translocation enzyme 1 messenger RNA expression levels in uterine fibroids may predict their postoperative recurrence

OBJECTIVES: To investigate the predictive value of long non-coding RNA (lncRNA) H19 and the ten-eleven translocation enzyme 1 (TET1) transcriptional expression in postoperative recurrence of uterine fibroids (UFs). METHODS: Seventy-five patients with UF, who underwent surgical treatment, were enrolled in the treatment group, and 60 healthy individuals were enrolled in the control group. The relative expression levels of lncRNA H19 and TET1 mRNA in the serum and UF tissues were analyzed. The patients were further divided into a better curative (BC) group and a poor efficacy (PE) group to analyze the predictive value of lncRNA H19 and TET1 and the independent risk factors affecting the recurrence of UF. RESULTS: Compared with the control group, lncRNA H19 expression levels were significantly higher, while TET1 expression levels were significantly lower in the treatment group (p<0.001). The area under the receiver operating characteristic (ROC) curve (AUC) values of the two indicators for diagnostic importance were found to be 0.872 and 0.826, respectively. Compared with the PE group, lncRNA H19 expression levels were significantly lower, while TET1 expression levels were significantly higher in the BC group (p<0.001). The AUC values of the two indicators for their predictive efficacy were 0.788 and 0.812, respectively. Logistic regression analysis showed that age, menarche age, maximum diameter of UFs, number of UFs, lncRNA H19 levels, and TET1 levels were independent risk factors affecting UF recurrence. The AUC values of lncRNA H19 and TET1 for their predictive value for postoperative recurrence were 0.814 and 0.765, respectively. CONCLUSIONS: The lncRNA H19 and TET1 have high diagnostic and predictive efficacy for determining the postoperative recurrence of UFs.

Effect of TET1-CD on proliferation and migration of breast cancer MDA-MB-231 cells and its underlying mechanism / 中国肿瘤生物治疗杂志

@# Objective: To investigate the effect of high expression of TET1 catalytic domain (TET1-CD) gene on the proliferation and migration of breast cancer MDA-MB-231 cells and its underlying mechanism. Methods: MDA-MB-231 cell line with high TET1-CD expression was established by lentiviral transfection. Real-time quantitative PCR was used to detect the mRNA expression of TET1-CD. Transwell assay and cell scratch assay were used to detect cell migration ability, MTT assay and colony formation assay were used to detect cell proliferation capacity. And WB was adopted to detect the expressions of EMT-related proteins (E-cadherin, Vimentin, MMP2) and Wnt, Hedgehog pathway-related proteins in MDA-MB-231 cells. Results: The MDA-MB-231 cell line with high TET1-CD expression was successfully constructed (all P<0.01). TET1-CD over-expression significantly inhibited the proliferation and migration of breast cancer MDA-MB-231 cells (P<0.01); in addition, TET1-CD over-expression increased the expression of E-cadherin, but down-regulated the expressions of Vimentin, MMP2, β-catenin, Gli1, C-myc and CyclinD1 (all P<0.05). Conclusion: TET1-CD may inhibit the proliferation and migration of breast cancer MDA-MB-231 cells by inhibiting the EMT through Wnt and HH signaling pathway.

The role of DNAhydroxymethylase TET1 in tumorigenesis / 中国肿瘤生物治疗杂志

@#[摘 要] TET1 （ten-eleven-translocation 1）是一种羟甲基化酶基因，该酶能够催化5甲基胞嘧啶（5-methyl-cytosine， 5mC）形成5 羟甲基胞嘧啶（5-hydroxymethyl-cytosine， 5hmC）， 在DNA甲基化调控中发挥重要作用。最近研究表明， T E T 1 的低表达与肿瘤发 生有关，可作为癌症治疗潜在标志物，表明 T E T 1 可作为肿瘤抑制基因。此外，除了它的双氧酶活性外， T E T 1 还可以诱导上皮细 胞间质转变，并充当调节基因转录的辅助活化因子，如癌症的低氧应答基因的调节因子。这表明 T E T 1 也可做为癌基因促进肿瘤 的发生。因此，在癌症和发育生物学中，TET1的调控机制是十分复杂的， T E T 1 基因突变也已有报道。本文就TET1在肿瘤发生中 的不同作用进行了综述，深入阐述TET1的作用对拓展DNA去甲基化机制的认识及发现肿瘤治疗新靶标具有重要价值。

Effect of Ligustri Lucidi Fructus on hepatic COX activity in normal rats and preliminary investigation of its DNA methylation mechanism / 中国中药杂志

The study aims to investigate the effect of Ligustri Lucidi Fructus on cytochrome c oxidase(COX) activity in rat hepatic tissues and explore its possible mechanism of DNA methylation. Male SD rats received aqueous extract of Ligustri Lucidi Fructus (2.0，6.0 g•kg⁻¹) by intragastric administration for 30 d. After the rats were sacrificed, hepatic tissues of rats were taken to detect COX activity, protein concentration of COX4I1, TET1 and DNMT3A protein levels, mRNA expression levels of Cox4i1, Dnmt3a and Tet1, and determine the DNA methylation frequency of Cox4i1.Results showed that both low and high doses of Ligustri Lucidi Fructus could significantly increase COX activity and concentration of COX4I1(P<0.05), with a decreasing tendency of both TET1 protein and DNMT3a protein expression； however, mRNA expression levels of Cox4i1, Dnmt3a and Tet1 were not significantly changed by Ligustri Lucidi Fructus. In addition, DNA methylation frequency of Cox4i1 in high dose group showed a declining tendency as compared with the blank control group, but without significant difference.These results indicated that Ligustri Lucidi Fructus had promotive effect on hepatic COX activity in rats, which may be achieved by increasing protein content of COX4I1. Moreover, a decreased tendency of DNMT3A protein could be one of the reasons for the lower trend of Cox4i1 methylation rate. In addition, Ligustri Lucidi Fructus may regulate the expression levels of DNMT3A and TET1 in the same direction and its mechanism is not clear.

Non-catalytic roles for TET1 protein negatively regulating neuronal differentiation through srGAP3 in neuroblastoma cells

The methylcytosine dioxygenases TET proteins (TET1, TET2, and TET3) play important regulatory roles in neural function. In this study, we investigated the role of TET proteins in neuronal differentiation using Neuro2a cells as a model. We observed that knockdown of TET1, TET2 or TET3 promoted neuronal differentiation of Neuro2a cells, and their overexpression inhibited VPA (valproic acid)-induced neuronal differentiation, suggesting all three TET proteins negatively regulate neuronal differentiation of Neuro2a cells. Interestingly, the inducing activity of TET protein is independent of its enzymatic activity. Our previous studies have demonstrated that srGAP3 can negatively regulate neuronal differentiation of Neuro2a cells. Furthermore, we revealed that TET1 could positively regulate srGAP3 expression independent of its catalytic activity, and srGAP3 is required for TET-mediated neuronal differentiation of Neuro2a cells. The results presented here may facilitate better understanding of the role of TET proteins in neuronal differentiation, and provide a possible therapy target for neuroblastoma.