Ten-eleven Translocation 1 Protein Research Articles

TET1 is a Diagnostic and Prognostic Biomarker Associated with Immune Infiltration in Papillary Thyroid Cancer.

To investigate the function of ten-eleven translocation 1 (TET1) and its underlying mechanism in papillary thyroid cancer (PTC). Using the RNA-Seq data based on GDC TCGA, we analyzed the gene expression pattern of TET1 in PTC. Immunohistochemistry was carried out to assess the TET1 protein level. Then, its diagnostic and prognostic functions were determined by various bioinformatics approaches. Enrichment analysis was performed to explore the potential pathways in which TET1 is mainly involved. Finally, the immune cell infiltration analysis was conducted and the association of TET1 mRNA expression with the expression levels of immune checkpoints, tumor mutation burden (TMB) score, microsatellite instability (MSI) score, and cancer stem cells (CSC) score was examined. TET1 expression was lower in PTC tissues compared with that in normal tissues (P < 0.01). Besides, TET1 had a certain value in diagnosing PTC, and low-TET1 mRNA expression led to favorable disease-specific survival (DSS) (P < 0.01). The enrichment analysis revealed autoimmune thyroid disease and cytokine-cytokine receptor interaction were the consistent pathways in which TET1 participated. TET1 was negatively correlated with the Stromal score and Immune score. The different proportions of immune cell subtypes were observed between high- and low-TET1 expression groups. Interestingly, TET1 mRNA expression was inversely related to the expression levels of immune checkpoints, and TMB, MSI, and CSC scores. TET1 might be a robust diagnostic and prognostic biomarker for PTC. TET1 affected the DSS of PTC patients possibly through the regulation of immune-related pathways and tumor immunity.

LINC00891 Attenuates the Proliferation and Metastasis of Osteosarcoma Cells via miR-27a-3p/TET1 Axis.

Objective: There is currently no adequate treatment for osteosarcoma, a bone malignancy that poses a serious threat to adolescents and children. The dysregulation of long noncoding RNAs is associated with many cancers, including osteosarcoma. LINC00891 expression is aberrant in endometrial cancer, lung cancer, and thyroid cancer, and likely regulate the malignant behavior of cancer. However, the potential function and mechanisms of LINC00891 in osteosarcoma progression remain unclear. Materials and Methods: LINC00891, miR-27a-3p, and TET1 mRNA expression in osteosarcoma cells were analyzed using quantitative reverse transcription-polymerase chain reaction. CCK-8 and Transwell experiments were performed on osteosarcoma cells to investigate proliferation, migration, and invasion, respectively. Ten-eleven translocation 1 (TET1) protein was analyzed using western blotting. Luciferase experiment was performed to investigate the interactions between LINC00891 with miR-27a-3p, and miR-27a-3p with TET1. Results: LINC00891 expression was dramatically decreased in the five osteosarcoma cell lines examined, particularly in 143B and SaoS-2 cells. LINC00891 overexpression due to plasmid transfection sharply blocked the proliferation, migration, and invasion of osteosarcoma cells. Dual-luciferase reporter experiments found that LINC00891 sponges miR-27a-3p, and LINC00891 overexpression sharply decreases miR-27a-3p expression. Transfection with miR-27a-3p mimic accelerated the malignant behaviors in LINC00891 overexpressed-osteosarcoma cells. Moreover, TET1 was a novel targeted-gene of miR-27a-3p. TET1 protein was significantly impeded, whereas LINC00891 overexpression elevated TET1 mRNA and protein in osteosarcoma cells. MiR-27a-3p overexpression inhibited TET1 mRNA and protein in osteosarcoma cells. Conclusions: Our study verified that LINC00891 attenuates the proliferation and metastasis of osteosarcoma cells via the miR-27a-3p/TET1 axis. This study clarifies a new mechanism and therapeutic target for the development of osteosarcoma.

Phosphorylation stabilized TET1 acts as an oncoprotein and therapeutic target in B cell acute lymphoblastic leukemia.

Although the overall survival rate of B cell acute lymphoblastic leukemia (B-ALL) in childhood is more than 80%, it is merely 30% in refractory/relapsed and adult patients with B-ALL. This demonstrates a need for improved therapy targeting this subgroup of B-ALL. Here, we show that the ten-eleven translocation 1 (TET1) protein, a dioxygenase involved in DNA demethylation, is overexpressed and plays a crucial oncogenic role independent of its catalytic activity in B-ALL. Consistent with its oncogenic role in B-ALL, overexpression of TET1 alone in normal precursor B cells is sufficient to transform the cells and cause B-ALL in mice within 3 to 4 months. We found that TET1 protein is stabilized and overexpressed because of its phosphorylation mediated by protein kinase C epsilon (PRKCE) and ATM serine/threonine kinase (ATM), which are also overexpressed in B-ALL. Mechanistically, TET1 recruits STAT5B to the promoters of CD72 and JCHAIN and promotes their transcription, which in turn promotes B-ALL development. Destabilization of TET1 protein by treatment with PKC or ATM inhibitors (staurosporine or AZD0156; both tested in clinical trials), or by pharmacological targeting of STAT5B, greatly decreases B-ALL cell viability and inhibits B-ALL progression in vitro and in vivo. The combination of AZD0156 with staurosporine or vincristine exhibits a synergistic effect on inhibition of refractory/relapsed B-ALL cell survival and leukemia progression in PDX models. Collectively, our study reveals an oncogenic role of the phosphorylated TET1 protein in B-ALL independent of its catalytic activity and highlights the therapeutic potential of targeting TET1 signaling for the treatment of refractory/relapsed B-ALL.

MXene Enhanced Photoactivity of Bi2O3/Bi2S3 Heterojunction with G-wire Superstructure for Photoelectrochemical Detection of TET1 Protein.

Ten-eleven translocation 1 (TET1) protein has the potential to accelerate the oxygenation of 5-methylcytosine to 5-hydroxymethylcytosine (5hmC); then the -CH2OH of 5hmC can further covalently react with -SH catalyzed by M.HhaI methyltransferase. A brand-new photoelectrochemical (PEC) detection technique for the TET1 protein was created in light of this. For this objective, the Bi2O3/Bi2S3 heterojunction was first prepared by a one-pot hydrothermal method and served for photosensitive materials. For further enhancing the photoactivity, Bi2O3/Bi2S3 was blended with MXene to form an energy band-matched structure, thus improving the migration kinetics of photogenerated carriers. For achieving a high sensitivity of detection, a DNA Walker incorporated with the nicking endonuclease (Nb.BbvCI enzyme)-assisted signal amplification strategy was presented to output exponential G-quadruplex fragments. Self-assembly of the free G-quadruplex sequence into a G-wire superstructure with the assistance of Mg2+ provided more loading sites for MB and amplified the PEC signal. The linear range of the biosensor was 0.1-10 μg/mL with a detection limit of 0.024 μg/mL (S/N = 3) for TET1 protein under optimal experimental conditions. The suitability of the proposed method was evaluated by inhibitor screening experiments and the influence of environmental degradation on the activity of TET1 protein.

Circ_0007919 exerts an anti-tumor role in colorectal cancer through targeting miR-942–5p/TET1 axis

Circular RNAs (circRNAs) are key regulators in the development of many cancers. The present study was aimed to investigate the mechanism by which circ_0007919 affected colorectal cancer (CRC) progression.The differentially expressed circRNA was screened out by analyzing the expression profile of circRNAs of CRC tissues. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed for detecting the expressions of circ_0007919, miR-942–5p, and ten-eleven translocation 1 (TET1) mRNA in CRC tissues and cell lines. Cell growth and migration were assessed by cell counting kit-8 (CCK-8) 5-bromo-2′-deoxyuridine (BrdU) and scratch assays. Bioinformatics analysis and dual-luciferase reporter assay were conducted to predict and validate the targeted relationships between circ_0007919 and miR-942–5p, as well as between miR-942–5p and TET1 mRNA. Besides, Western blot was conducted for detecting TET1 protein expression in CRC cells. It was revealed that, in CRC tissues and cell lines, circ_0007919 and TET1 expressions were reduced whereas miR-942–5p expression was enhanced. It was also revealed that circ_0007919 overexpression markedly suppressed CRC cell growth and migration. In addition, circ_0007919 could competitively bind with miR-942–5p to increase the expression of miR-942–5p’s target gene TET1. Collectively, circ_0007919 inhibits CRC cell growth and migration via regulating the miR-942–5p/TET1 axis. This study helps to better understand the molecular mechanism of CRC progression.

Ten-Eleven Translocation 1 Promotes Malignant Progression of Cholangiocarcinoma With Wild-Type Isocitrate Dehydrogenase 1.

Cholangiocarcinoma (CCA) is a highly lethal disease without effective therapeutic approaches. The whole-genome sequencing data indicate that about 20% of patients with CCA have isocitrate dehydrogenase 1 (IDH1) mutations, which have been suggested to target 2-oxoglutarate (OG)-dependent dioxygenases in promoting CCA carcinogenesis. However, the clinical study indicates that patients with CCA and mutant IDH1 have better prognosis than those with wild-type IDH1, further complicating the roles of 2-OG-dependent enzymes. This study aimed to clarify if ten-eleven translocation 1 (TET1), which is one of the 2-OG-dependent enzymes functioning in regulating 5-hydroxymethylcytosine (5hmC) formation, is involved in CCA progression. By analyzing The Cancer Genome Atlas (TCGA) data set, TET1 mRNA was found to be substantially up-regulated in patients with CCA when compared with noncancerous bile ducts. Additionally, TET1 protein expression was significantly elevated in human CCA tumors. CCA cells were challenged with α-ketoglutarate (α-KG) and dimethyl-α-KG (DM-α-KG), which are cosubstrates for TET1 dioxygenase. The treatments with α-KG and DM-α-KG promoted 5hmC formation and malignancy of CCA cells. Molecular and pharmacological approaches were used to inhibit TET1 activity, and these treatments substantially suppressed 5hmC and CCA carcinogenesis. Mechanistically, it was found that knockdown of TET1 may suppress CCA progression by targeting cell growth and apoptosis through epigenetic regulation. Consistently, targeting TET1 significantly inhibited CCA malignant progression in a liver orthotopic xenograft model by targeting cell growth and apoptosis. Our data suggest that expression of TET1 is highly associated with CCA carcinogenesis. It will be important to evaluate TET1 expression in CCA tumors before application of the IDH1 mutation inhibitor because the inhibitor suppresses 2-hydroxyglutarate expression, which may result in activation of TET, potentially leading to CCA malignancy.

Tet1 Isoforms Differentially Regulate Gene Expression, Synaptic Transmission, and Memory in the Mammalian Brain.

The dynamic regulation of DNA methylation in postmitotic neurons is necessary for memory formation and other adaptive behaviors. Ten-eleven translocation 1 (TET1) plays a part in these processes by oxidizing 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), thereby initiating active DNA demethylation. However, attempts to pinpoint its exact role in the nervous system have been hindered by contradictory findings, perhaps due in part, to a recent discovery that two isoforms of the Tet1 gene are differentially expressed from early development into adulthood. Here, we demonstrate that both the shorter transcript (Tet1S) encoding an N-terminally truncated TET1 protein and a full-length Tet1 (Tet1FL) transcript encoding canonical TET1 are co-expressed in the adult mouse brain. We show that Tet1S is the predominantly expressed isoform and is highly enriched in neurons, whereas Tet1FL is generally expressed at lower levels and more abundant in glia, suggesting their roles are at least partially cell type-specific. Using viral-mediated, isoform and neuron-specific molecular tools, we find that the individual repression of each transcript leads to the dysregulation of unique gene ensembles and contrasting changes in basal synaptic transmission. In addition, Tet1S repression enhances, while Tet1FL impairs, hippocampal-dependent memory in male mice. Together, our findings demonstrate that each Tet1 isoform serves a distinct role in the mammalian brain.SIGNIFICANCE STATEMENT In the brain, activity-dependent changes in gene expression are required for the formation of long-term memories. DNA methylation plays an essential role in orchestrating these learning-induced transcriptional programs by influencing chromatin accessibility and transcription factor binding. Once thought of as a stable epigenetic mark, DNA methylation is now known to be impermanent and dynamically regulated, driving neuroplasticity in the brain. We found that Tet1, a member of the ten-eleven translocation (TET) family of enzymes that mediates removal of DNA methyl marks, is expressed as two separate isoforms in the adult mouse brain and that each differentially regulates gene expression, synaptic transmission and memory formation. Together, our findings demonstrate that each Tet1 isoform serves a distinct role in the CNS.

Downregulation of TET1 Promotes Bladder Cancer Cell Proliferation and Invasion by Reducing DNA Hydroxymethylation of AJAP1.

Ten-eleven translocation 1 (TET1) is a member of methylcytosine dioxygenase, which catalyzes 5-methylcytosine (5 mC) to 5-hydroxymethylcytosine (5 hmC) to promote the demethylation process. The dysregulated TET1 protein and 5 hmC level were reported to either suppress or promote carcinogenesis in a cancer type-dependent manner. Currently, the role of TET1 in the development of urinary bladder cancer (UBC) and its underlying molecular mechanisms remain unclear. Herein, we found that TET1 expression was downregulated in UBC specimens compared with normal urothelium and was inversely related to tumor stage and grade and overall survival, suggesting its negative association with UBC progression. TET1 silencing in UBC cells increased cell proliferation and invasiveness while the ectopic expression of wild-type TET1-CD, but not its enzymatic inactive mutant, reversed these effects and suppressed tumorigenicity in vivo. In addition, as a direct regulator of TET1 activity, vitamin C treatment increased 5 hmC level and inhibited the anchorage-independent growth and tumorigenicity of UBC cells. Furthermore, we found that TET1 maintained the hypomethylation in the promoter of the AJAP1 gene, which codes for adherens junction-associated protein 1. The downregulation of AJAP1 reversed TET1-CD-induced nuclear translocation of β-catenin, thus inhibiting the expression of its downstream genes. In human UBC specimens, AJAP1 is frequently downregulated and positively associated with TET1. Notably, low expression levels of both TET1 and AJAP1 predict poor prognosis in UBC patients. In conclusion, we found that the frequently downregulated TET1 level reduces the hydroxymethylation of AJAP1 promoter and subsequently activates β-catenin signaling to promote UBC development. The downregulation of both TET1 and AJAP1 might be a promising prognostic biomarker for UBC patients.

HIF1α/TET1 Pathway Mediates Hypoxia-Induced Adipocytokine Promoter Hypomethylation in Human Adipocytes.

Obesity is associated with the accumulation of dysfunctional adipose tissue that secretes several pro-inflammatory cytokines (adipocytokines). Recent studies have presented evidence that adipose tissues in obese individuals and animal models are hypoxic, which may result in upregulation and stabilization of the hypoxia inducible factor HIF1α. Epigenetic mechanisms such as DNA methylation enable the body to respond to microenvironmental changes such as hypoxia and may represent a mechanistic link between obesity-associated hypoxia and upregulated inflammatory adipocytokines. The purpose of this study was to investigate the role of hypoxia in modifying adipocytokine DNA methylation and subsequently adipocytokine expression. We suggested that this mechanism is mediated via the DNA demethylase, ten-eleven translocation-1 (TET1), transcription of which has been shown to be induced by HIF1α. To this end, we studied the effect of hypoxia (2% O2) in differentiated subcutaneous human adipocytes in the presence or absence of HIF1α stabilizer (Dimethyloxalylglycine (DMOG), 500 μM), HIF1α inhibitor (methyl 3-[[2-[4-(2-adamantyl) phenoxy] acetyl] amino]-4-hydroxybenzoate, 30 μM), or TET1-specific siRNA. Subjecting the adipocytes to hypoxia significantly induced HIF1α and TET1 protein levels. Moreover, hypoxia induced global hydroxymethylation, reduced adipocytokine DNA promoter methylation, and induced adipocytokine expression. These effects were abolished by either HIF1α inhibitor or TET1 gene silencing. The major hypoxia-responsive adipocytokines were leptin, interleukin-1 (IL6), IL1β, tumor necrosis factor α (TNFα), and interferon γ (IFNγ). Overall, these data demonstrate an activation of the hydroxymethylation pathway mediated by TET1. This pathway contributes to promoter hypomethylation and gene upregulation of the inflammatory adipocytokines in adipocytes in response to hypoxia.

MiR-30a as Potential Therapeutics by Targeting TET1 through Regulation of Drp-1 Promoter Hydroxymethylation in Idiopathic Pulmonary Fibrosis

Several recent studies have indicated that miR-30a plays critical roles in various biological processes and diseases. However, the mechanism of miR-30a participation in idiopathic pulmonary fibrosis (IPF) regulation is ambiguous. Our previous study demonstrated that miR-30a may function as a novel therapeutic target for lung fibrosis by blocking mitochondrial fission, which is dependent on dynamin-related protein1 (Drp-1). However, the regulatory mechanism between miR-30a and Drp-1 is yet to be investigated. Additionally, whether miR-30a can act as a potential therapeutic has not been verified in vivo. In this study, the miR-30a expression in IPF patients was evaluated. Computational analysis and a dual-luciferase reporter assay system were used to identify the target gene of miR-30a, and cell transfection was utilized to confirm this relationship. Ten–eleven translocation 1 (TET1) was validated as a direct target of miR-30a, and miR-30a mimic and inhibitor transfection significantly reduced and increased the TET1 protein expression, respectively. Further experimentation verified that the TET1 siRNA interference could inhibit Drp-1 promoter hydroxymethylation. Finally, miR-30a agomir was designed and applied to identify and validate the therapeutic effect of miR-30a in vivo. Our study demonstrated that miR-30a could inhibit TET1 expression through base pairing with complementary sites in the 3′untranslated region to regulate Drp-1 promoter hydroxymethylation. Furthermore, miR-30a could act as a potential therapeutic target for IPF.

TET1 Promotes Leukemic Growth in T-ALL Via Maintenance of 5-Hydroxymethylation Marks and Can be Antagonized By the PARP Inhibitor Olaparib

T-cell acute lymphoid leukemia (T-ALL) is an aggressive hematological cancer predominantly occurring in children and adolescents. T-ALL is characterized by aberrant expression of genes involved in T-cell differentiation and self-renewal accompanied by aberrant DNA cytosine methylation patterns. The mechanisms underlying these aberrations are not well understood. The Ten-eleven translocation 1 (TET1) enzyme is an iron-dependent dioxygenase that catalyzes the oxidation of 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC) and plays a key role in active DNA demethylation and regulation of gene expression. Using quantitative real time (qRT)-PCR we now demonstrate that T-ALL is characterized by high and aberrant expression of TET1: TET1 was significantly and >20-fold higher expressed in human T-ALL cell lines compared to other B-lymphoid or myeloid leukemia cell lines (p<0.001, n=3). This was confirmed in primary patient samples, in which TET1 was more than 10-fold higher expressed in 95% of T-ALL cases (n=10) compared to other leukemia subtypes (B-ALL, n=29; AML, n=39; CLL, n=23, p<0.001). Furthermore, expression levels of TET1 in T-ALL patient samples were over 50-fold higher than in normal PB and BM derived healthy CD3+ T cells (n=6, p<0.001) in line with published cDNA microarray data from a large patient cohort of 174 T-ALL cases (Haferlach et al., JCO 2010). Knockdown (KD) of TET1 mRNA using two independent shRNAs in T-ALL cell lines adversely affected their cell growth (>70% reduction compared to scrambled, p<0.001, n=4) clonogenicity (>70% reduction compared to scrambled, p<0.001, n=4) and blocked cells in the G2/M phase of the cell cycle in vitro (n=3). Furthermore, TET1 KD significantly reduced the leukemic engraftment potential of T-ALL cell line Jurkat in xenografts (shRNA, n=16; scrambled, n=8). Global analysis of 5hmC levels using hMeDIP-seq performed on TET1 depleted Jurkat cells revealed lower global 5hmC levels as compared to cells transduced with scrambled control (n=2). Promoters (-5kb TSS) of 5,181 genes showed reduction of 5hmC marks (log2 fold diff.; p-value < 1e-10). Global 5mC analysis (MeDIP-seq) revealed 12,007 genes that gained 5mC marks at their promoters as a result of TET1 KD (log2 fold diff. > 1.5; p-value < 1-10). Of note, genes demonstrating a loss of 5hmC marks and corresponding a gain in 5mC marks on their promoters belonged to gene families involved innucleosome organization (HIST family), DNA damage response (DDR)(RAD, PARP), T-cell development (NOTCH3, RUNX1, LEF1) and homeobox genes (q-value < 1e-5). These changes were paralleled by changes in expression after TET1 depletion as measured by RNA-Seq in Jurkat cells: GO TERM analysis (log2 fold diff. > 1.5; p<0.05) revealed deregulation of genes belonging to nucleosome assembly, DNA damage, nucleosome organization and transcriptional deregulation in cancer. In line with these observations these pathways showed differential expression in T-ALL patients divided into the categories high vs. low TET1 expression based on previously published microarray data (Haferlach et al., JCO 2010) (median as cut-off; n=174)(log2 fold diff. >1.5; p<0.05).The aberrantly high TET1 expression in T-ALL cell lines shares a potential causal relationship with the hypomethylated status of the TET1 promoter (determined by LC/MS), and the enrichment of euchromatic marks such as H3K4me3 and acetylated H3 as determined by ChIP-qPCR. Since it was shown that PARP activity positively influences TET1 expression by regulating its promoter epigenetically, we tested the impact of the PARP inhibitor olaparib on TET1 activity in our model: of note, aberrant expression of TET1 could be reverted by the PARP inhibitor olaparib, which induced reduction of euchromatic marks on the TET1 promoter, in parallel with decreased TET1 expression and protein levels as well as 5hmC levels in Jurkat cells without affecting expression of other TET family members. Olaparib treatment caused a >75% reduction in cell growth and clonogenicity of T-ALL cell lines in vitro (n=3) and delayed leukemic engraftment in NSG mice (42%±8 in scrambled vs 9%±7 for the shRNAs, n=4 per arm; p<0.001). In conclusion, these data demonstrate for the first time that TET1 plays an important oncogenic role in T-ALL. We also identify PARPs as upstream regulators of TET1 in T-ALL, opening the way to antagonize TET1 pharmacologically in this poor prognosis leukemia. DisclosuresMulaw:NuGEN: Honoraria. Buske:Celltrion, Inc.: Consultancy, Honoraria.

Genomic and epigenomic analysis of high-risk prostate cancer reveals changes in hydroxymethylation and TET1.

The clinical heterogeneity of prostate cancer (PCa) makes it difficult to identify those patients that could benefit from more aggressive treatments. As a contribution to a better understanding of the genomic changes in the primary tumor that are associated with the development of high-risk disease, we performed exome sequencing and copy number determination of a clinically homogeneous cohort of 47 high-risk PCas. We confirmed recurrent mutations in SPOP, PTEN and TP53 among the 850 point mutations we detected. In seven cases, we discovered genomic aberrations in the TET1 (Ten-Eleven Translocation 1) gene which encodes a DNA hydroxymethylase than can modify methylated cytosines in genomic DNA and thus is linked with gene expression changes. TET1 protein levels were reduced in tumor versus non-tumor prostate tissue in 39 of 40 cases. The clinical relevance of changes in TET1 levels was demonstrated in an independent PCa cohort, in which low TET1 mRNA levels were significantly associated with worse metastases-free survival. We also demonstrate a strong reduction in hydroxymethylated DNA in tumor tissue in 27 of 41 cases. Furthermore, we report the first exploratory (h)MeDIP-Seq analyses of eight high-risk PCa samples. This reveals a large heterogeneity in hydroxymethylation changes in tumor versus non-tumor genomes which can be linked with cell polarity.

5-Hydroxymethylcytosine discriminates between parathyroid adenoma and carcinoma

BackgroundPrimary hyperparathyroidism is characterized by enlarged parathyroid glands due to an adenoma (80–85 %) or multiglandular disease (~15 %) causing hypersecretion of parathyroid hormone (PTH) and generally hypercalcemia. Parathyroid cancer is rare (<1–5 %). The epigenetic mark 5-hydroxymethylcytosine (5hmC) is reduced in various cancers, and this may involve reduced expression of the ten-eleven translocation 1 (TET1) enzyme. Here, we have performed novel experiments to determine the 5hmC level and TET1 protein expression in 43 parathyroid adenomas (PAs) and 17 parathyroid carcinomas (PCs) from patients who had local invasion or metastases and to address a potential growth regulatory role of TET1.ResultsThe global 5hmC level was determined by a semi-quantitative DNA immune-dot blot assay in a smaller number of tumors. The global 5hmC level was reduced in nine PCs and 15 PAs compared to four normal tissue samples (p < 0.05), and it was most severely reduced in the PCs. By immunohistochemistry, all 17 PCs stained negatively for 5hmC and TET1 showed negative or variably heterogeneous staining for the majority. All 43 PAs displayed positive 5hmC staining, and a similar aberrant staining pattern of 5hmC and TET1 was seen in about half of the PAs. Western blotting analysis of two PCs and nine PAs showed variable TET1 protein expression levels. A significantly higher tumor weight was associated to PAs displaying a more severe aberrant staining pattern of 5hmC and TET1. Overexpression of TET1 in a colony forming assay inhibited parathyroid tumor cell growth.Conclusions5hmC can discriminate between PAs and PCs. Whether 5hmC represents a novel marker for malignancy warrants further analysis in additional parathyroid tumor cohorts. The results support a growth regulatory role of TET1 in parathyroid tissue.Electronic supplementary materialThe online version of this article (doi:10.1186/s13148-016-0197-2) contains supplementary material, which is available to authorized users.

Expression Features of DNA Methylcytosine Dioxygenase Ten-eleven Translocation 1 in Human Dental Pulp Cells

IntroductionHuman dental pulp cells (hDPCs) can specifically generate reparative dentin under external stimuli, and numerous mechanisms are involved in their odontogenic differentiation process. Ten-eleven translocation 1 (TET1) is a recently discovered DNA dioxygenase that plays important roles in promoting DNA demethylation and transcriptional regulation. Although several studies regarding its effect on cell differentiation and proliferation have been conducted, the expression and function of TET1 have not yet been characterized in hDPCs. The purpose of this study was to explore the expression features of TET1 in hDPCs. MethodsCellular TET1 localization in hDPCs was determined by immunofluorescence. The expression pattern of TET1 and its potential changes during odontogenic induction were confirmed using real-time quantitative polymerase chain reaction and Western blot analyses. ResultsTET1 existed in both the cytoplasm and the nucleus of the hDPCs. During serial cell passaging, TET1 expression significantly increased until the 6th passage and then decreased from the 7th–9th passages (P < .05, n = 3). TET1 gene and protein expression increased during the odontogenic differentiation of the hDPCs in a time-dependent manner (P < .05, n = 3). ConclusionsTET1 messenger RNA and protein were both present in the hDPCs. TET1 expression increased during early spontaneous differentiation and odontogenic induction.

Decreased expression of ten-eleven translocation 1 protein is associated with some clinicopathological features in gastric cancer

A decrease in ten-eleven translocation 1 (TET1) transcript and 5-Hydroxymethylcytosine (5hmC) levels has recently been demonstrated in primary gastric cancer (GC). However, little is known about TET1 protein levels in gastric tumoral and nontumoral tissue. Therefore, using reverse transcription, real-time quantitative polymerase chain reaction and western blotting analysis, we determined the TET1 transcript and protein levels in tumoral and nontumoral tissue from 38 patients with GC. We also assessed the association between the decrease in TET1 transcript and protein levels and some clinicopathological features in primary GC. We found significantly decreased levels of TET1 transcript (P=0.0023) and protein (P=0.00024) in primary tumoral tissues as compared to nontumoral tissues in patients with GC. Moreover, we also observed significantly lower amounts of TET1 transcript (P=0.03) and protein (P=0.00018) in tumoral tissues in patients aged>60. We also found significant lowered TET1 protein levels in male patients (P=0.0014), stomach (P=0.044) and cardia (P=0.013) tumor localization, T3 depth of invasion (P=0.019), N1 (P=0.012) and N3 lymph node metastasis (P=0.013) and G3 histological grade (P=0.0012). There were also significant decreases in TET1 transcript levels in female patients (P=0.042), intestinal histological types (P=0.0079) and T4 depth of invasion (P=0.037). Our results demonstrated that a decrease in TET1 transcript and protein levels is associated with some clinicopathological features in GC.