SETD5 regulates the OGT-catalyzed O-GlcNAcylation of RNA polymerase II, which is involved in the stemness of colorectal cancer cells.

The dosage-dependent recruitment of RNA polymerase II (Pol II) at the promoters of genes related to neurodevelopment and stem cell maintenance is required for transcription by the fine-tuned expression of SET-domain-containing protein 5 (SETD5). Pol II O-GlcNAcylation by O-GlcNAc transferase (OGT) is critical for preinitiation complex formation and transcription cycling. SETD5 dysregulation has been linked to stem cell-like properties in some cancer types; however, the role of SETD5 in cancer cell stemness has not yet been determined.

JIB-04, a Pan-Inhibitor of Histone Demethylases, Targets Histone-Lysine-Demethylase-Dependent AKT Pathway, Leading to Cell Cycle Arrest and Inhibition of Cancer Stem-Like Cell Properties in Hepatocellular Carcinoma Cells.

JIB-04, a pan-histone lysine demethylase (KDM) inhibitor, targets drug-resistant cells, along with colorectal cancer stem cells (CSCs), which are crucial for cancer recurrence and metastasis. Despite the advances in CSC biology, the effect of JIB-04 on liver CSCs (LCSCs) and the malignancy of hepatocellular carcinoma (HCC) has not been elucidated yet. Here, we showed that JIB-04 targeted KDMs, leading to the growth inhibition and cell cycle arrest of HCC, and abolished the viability of LCSCs.

AMBRA1 Negatively Regulates the Function of ALDH1B1, a Cancer Stem Cell Marker, by Controlling Its Ubiquitination.

Activating molecule in Beclin-1-regulated autophagy (AMBRA1), a negative regulator of tumorigenesis, is a substrate receptor of the ubiquitin conjugation system. ALDH1B1, an aldehyde dehydrogenase, is a cancer stem cell (CSC) marker that is required for carcinogenesis via upregulation of the β-catenin pathway. Although accumulating evidence suggests a role for ubiquitination in the regulation of CSC markers, the ubiquitination-mediated regulation of ALDH1B1 has not been unraveled.

BRPF3-HUWE1-mediated regulation of MYST2 is required for differentiation and cell-cycle progression in embryonic stem cells.

Brpf-histone acetyltransferase (HAT) complexes have important roles in embryonic development and regulating differentiation in ESCs. Among Brpf family, Brpf3 is a scaffold protein of Myst2 histone acetyltransferase complex that plays crucial roles in gene regulation, DNA replication, development as well as maintaining pluripotency in embryonic stem cells (ESCs). However, its biological functions in ESCs are not elucidated.

JIB-04, A Small Molecule Histone Demethylase Inhibitor, Selectively Targets Colorectal Cancer Stem Cells by Inhibiting the Wnt/β-Catenin Signaling Pathway.

Although several epigenetic modulating drugs are suggested to target cancer stem cells (CSCs), additional identification of anti-CSC drugs is still necessary. Here we showed that JIB-04, a pan-selective inhibitor of histone demethylase(s), was identified as a small molecule that selectively target colorectal CSCs. Our data showed that JIB-04 is capable of reducing self-renewal and stemness of colorectal CSCs in three different colorectal cancer cell lines.

Tousled-like kinase 1 is a negative regulator of core transcription factors in murine embryonic stem cells.

Although the differentiation of pluripotent cells in embryonic stem cells (ESCs) is often associated with protein kinase-mediated signaling pathways and Tousled-like kinase 1 (Tlk1) is required for development in several species, the role of Tlk1 in ESC function remains unclear. Here, we used mouse ESCs to study the function of Tlk1 in pluripotent cells. The knockdown (KD)-based Tlk1-deficient cells showed that Tlk1 is not essential for ESC self-renewal in an undifferentiated state.

SET domain-containing protein 5 is required for expression of primordial germ cell specification-associated genes in murine embryonic stem cells.

Primordial germ cell (PGC) specification is one of the most fundamental processes in developmental biology. Because PGCs are a common source of both gametes, generation of PGCs from embryonic stem cells (ESCs) is a useful model for analysing the germ line lineage. Although several studies focused on the role of epigenetic regulation on PGC differentiation from ESCs in vitro have been published, germ line commitment remains poorly understood.

Kinetic analysis of de novo centriole assembly in heat-shocked mammalian cells.

Mammalian cells are capable of de novo centriole formation after the removal of existing centrioles. This suggests that de novo centriole assembly is repressed in normally duplicating cells to maintain a constant number of centrioles in the cells. However, neither the mechanism of de novo centriole assembly nor that of its hypothesized repression is understood due to the lack of an experimental system.

The BRPF2/BRD1-MOZ complex is involved in retinoic acid-induced differentiation of embryonic stem cells.

The scaffold protein BRPF2 (also called BRD1), a key component of histone acetyltransferase complexes, plays an important role in embryonic development, but its function in the differentiation of embryonic stem cells (ESCs) remains unknown. In the present study, we investigated whether BRPF2 is involved in mouse ESC differentiation. BRPF2 depletion resulted in abnormal formation of embryoid bodies, downregulation of differentiation-associated genes, and persistent maintenance of alkaline phosphatase activity even after retinoic acid-induced differentiation, indicating impaired differentiation of BRPF2-depleted ESCs.

Calmidazolium chloride inhibits growth of murine embryonal carcinoma cells, a model of cancer stem-like cells.

Calmidazolium chloride (CMZ) is widely used as a calmodulin (CaM) antagonist, but is also known to induce apoptosis in certain cancer cell lines. However, in spite of the importance of cancer stem cells (CSCs) in cancer therapy, the effects of CMZ on CSCs are not yet well understood. We investigated the effects of CMZ on the F9 embryonal carcinoma cell (ECC) line as a surrogate model of CSCs.

The histone acetyltransferase Myst2 regulates Nanog expression, and is involved in maintaining pluripotency and self-renewal of embryonic stem cells.

The histone acetyltransferase Myst2 plays an important role in embryogenesis, but its function in undifferentiated ES cells remains poorly understood. Here, we show that Myst2 plays a role in pluripotency and self-renewal of ES cells. Myst2 deficiency results in loss of characteristic morphology, decreased alkaline phosphatase staining and reduced histone acetylation, as well as aberrant expression of pluripotency and differentiation markers.

Nuclear import of human histone lysine-specific demethylase LSD1.

Upregulation and nuclear retention of the human histone demethylase LSD1 are correlated with aggressiveness and poor outcome of several cancer types, but the molecular mechanism of LSD1 nuclear import remains unclear. Here, we found that the N-terminal flexible region of LSD1 contains a nuclear localization signal (NLS), (112)RRKRAK(117). Mutation or deletion of the NLS completely abolished the nuclear import of LSD1, suggesting the motif is a bona fide NLS.

CDK2-dependent phosphorylation of Suv39H1 is involved in control of heterochromatin replication during cell cycle progression.

Although several studies have suggested that the functions of heterochromatin regulators may be regulated by post-translational modifications during cell cycle progression, regulation of the histone methyltransferase Suv39H1 is not fully understood. Here, we demonstrate a direct link between Suv39H1 phosphorylation and cell cycle progression. We show that CDK2 phosphorylates Suv39H1 at Ser391 and these phosphorylation levels oscillate during the cell cycle, peaking at S phase and maintained during S-G2-M phase.

The histone demethylase LSD1 is required for estrogen-dependent S100A7 gene expression in human breast cancer cells.

S100A7, a member of S100 calcium binding protein family, is highly associated with breast cancer. However, the molecular mechanism of S100A7 regulation remains unclear. Here we show that long-term treatment with estradiol stimulated S100A7 expression in MCF7 breast cancer cells at both the transcriptional and translational levels.

Epigenetic up-regulation of leukemia inhibitory factor (LIF) gene during the progression to breast cancer.

The interleukin 6 family of cytokines including leukemia inhibitory factor (LIF) regulates the progression of several types of cancer. However, although LIF overexpression during breast cancer progression was observed in our previous report, the molecular mechanisms responsible for this deregulation remain largely unknown. Here we show that LIF expression is epigenetically up-regulated via DNA demethylation and changes in histone methylation status within its promoter region in the isogenic MCF10 model.

Epigenetic silencing of TNFSF7 (CD70) by DNA methylation during progression to breast cancer.

To escape the immune system, tumor cells may remove surface molecules such as the major histocompatibility complex (MHC) and co-stimulatory molecules, which are essential for recognition by lymphocytes. Down-regulation of the co-stimulatory molecules CD70 (TNFSF7) and CD80 may contribute to tumor cell survival; however, the mechanism of down-regulation of the TNFSF7 gene during tumorigenesis is poorly understood. Here we present evidence indicating that TNFSF7 gene expression is epigenetically down-regulated via DNA hypermethylation within its promoter region during progression in breast cancer cells in the isogenic MCF10 model.

Molecular signatures associated with transformation and progression to breast cancer in the isogenic MCF10 model.

Comparative microarray analyses provided insight into understanding transcript changes during cancer progression; however, a reproducible signature underlying breast carcinogenesis has yet to be little available. We utilized gene expression profiling to define molecular signatures associated with transformation and cancer progression in a series of isogenic human breast cancer cell lines including a normal, benign, noninvasive and invasive carcinoma. Clustering analysis revealed four distinct expression patterns based on upregulation or downregulation patterns.

Methylations of histone H3 lysine 9 and lysine 36 are functionally linked to DNA replication checkpoint control in fission yeast.

Recently, histone H4 lysine 20 and H3 lysine 79 methylations were functionally linked to DNA damage checkpoint. The crosstalk between histone methylation and the S-M checkpoint, however, has remained unclear. Here, we show that H3 lysine 9 (K9) and lysine 36 (K36) methylations catalyzed by two histone methyltransferases Clr4 and Set2 are involved in hydroxyurea (HU)-induced replication checkpoint.

Novel polymorphisms in the SUV39H2 histone methyltransferase and the risk of lung cancer.

Histone H3 lysine 9 (H3-K9) methylation and DNA methylation are important features of mammalian heterochromatin. Suppressor of variegation 3-9 homolog 2 (SUV39H2) is the histone methyltransferase that is required to methylate H3-K9, leading to transcriptional repression or silencing of target genes. In this study, we investigated the association of SUV39H2 polymorphisms and the risk of lung cancer.

Dynamic regulation of replication independent deposition of histone H3 in fission yeast.

Recently, a histone H3 variant in Drosophila and humans, the H3.3 protein, was shown to replace canonical H3 in active chromatin in a replication-independent (RI) manner. In the fission yeast Schizosaccharomyces pombe, there exists a single form of H3, which is equivalent to H3.

SUMO modification is involved in the maintenance of heterochromatin stability in fission yeast.

Several studies have suggested that SUMO may participate in the regulation of heterochromatin, but direct evidence is lacking. Here, we present a direct link between sumoylation and heterochromatin stability. SUMO deletion impaired silencing at heterochromatic regions and induced histone H3 Lys4 methylation, a hallmark of active chromatin in fission yeast.

Regulation of Swi6/HP1-dependent heterochromatin assembly by cooperation of components of the mitogen-activated protein kinase pathway and a histone deacetylase Clr6.

A study of gene silencing within the mating-type region of fission yeast defines two distinct pathways responsible for the establishment of heterochromatin assembly. One is RNA interference-dependent and acts on centromere-homologous repeats (cenH). The other is a stochastic Swi6 (the fission yeast HP1 homolog)-dependent mechanism that is not fully understood.

Two ubiquitin-conjugating enzymes, Rhp6 and UbcX, regulate heterochromatin silencing in Schizosaccharomyces pombe.

Methylation of histone H3 has been linked to the assembly of higher-order chromatin structures. Very recently, several examples, including the Schizosaccharomyces pombe mating-type region, chicken beta-globin locus, and inactive X-chromosome, revealed that H3-Lys9-methyl (Me) is associated with silent chromatin while H3-Lys4-Me is prominent in active chromatin. Surprisingly, it was shown that homologs of Drosophila Su(var)3-9 specifically methylate the Lys9 residue of histone H3.

Hrp3, a chromodomain helicase/ATPase DNA binding protein, is required for heterochromatin silencing in fission yeast.

Hrp3, a paralog of Hrp1, is a novel member of the CHD1 (chromo-helicase/ATPase-DNA binding 1) protein family of Schizosaccharomyces pombe. Although it has been considered that CHD1 proteins are required for chromatin modifications in transcriptional regulations, little is known about their roles in vivo. In this study, we examined the effects of Hrp3 on heterochromatin silencing using several S.

Fibrillarin binds to a 3' cis-regulatory element in pre-mRNA of uvi15+ in fission yeast.

uvi15+ is induced by various stresses including exposure to UV-light. Previously, we demonstrated that the UV-induction is mainly regulated at the post-transcriptional level through a cis-acting element in the pre-mRNA. Here we show that deletion analyses define an 18-nt element responsible for the UV-induction.