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Recruitment of non-canonical BCOR-PRC1.1 to non-methylated CpG islands via KDM2B plays a fundamental role in transcription control during developmental processes and cancer progression. However, the mechanism is still largely unknown on how this recruitment is regulated. Here, we unveiled the importance of the Poly-D/E regions within the linker of BCOR for its binding to KDM2B. Interestingly, we also demonstrated that these negatively charged Poly-D/E regions on BCOR play autoinhibitory roles in liquid-liquid phase separation (LLPS) of BCOR ANK-linker-PUFD /PCGF1 RAWUL . Through neutralizing negative charges of these Poly-D/E regions, Ca 2+ not only weakens the interaction between BCOR/PCGF1 and KDM2B, but also promotes co-condensation of the enzymatic core of BCOR-PRC1.1 with KDM2B into liquid-like droplet. Accordingly, we propose that Ca 2+ could modulate the compartmentation and recruitment of the enzymatic core of BCOR-PRC1.1 on KDM2B target loci. Thus, our finding advances the mechanistic understanding on how the tethering of BCOR-PRC1.1 enzymatic core to KDM2B is regulated., (© 2024. The Author(s).)

Early-life iron deficiency (ID) causes long-term neurocognitive impairments and gene dysregulation that can be partially mitigated by prenatal choline supplementation. The long-term gene dysregulation is hypothesized to underlie cognitive dysfunction. However, mechanisms by which iron and choline mediate long-term gene dysregulation remain unknown. In the present study, using a well-established rat model of fetal-neonatal ID, we demonstrated that ID downregulated hippocampal expression of the gene encoding JmjC-ARID domain-containing protein 1B (JARID1B), an iron-dependent histone H3K4 demethylase, associated with a higher histone deacetylase 1 (HDAC1) enrichment and a lower enrichment of acetylated histone H3K9 (H3K9ac) and phosphorylated cAMP response element-binding protein (pCREB). Likewise, ID reduced transcriptional capacity of the gene encoding brain-derived neurotrophic factor (BDNF), a target of JARID1B, associated with repressive histone modifications such as lower H3K9ac and pCREB enrichments at the Bdnf promoters in the adult rat hippocampus. Prenatal choline supplementation did not prevent the ID-induced chromatin modifications at these loci but induced long-lasting repressive chromatin modifications in the iron-sufficient adult rats. Collectively, these findings demonstrated that the iron-dependent epigenetic mechanism mediated by JARID1B accounted for long-term Bdnf dysregulation by early-life ID. Choline supplementation utilized a separate mechanism to rescue the effect of ID on neural gene regulation. The negative epigenetic effects of choline supplementation in the iron-sufficient rat hippocampus necessitate additional investigations prior to its use as an adjunctive therapeutic agent.

Metformin has been tested as an anti-cancer therapy with potential to improve conventional chemotherapy. However, in some cases, metformin fails to sensitize tumors to chemotherapy. Here we test if the presence of P53 could predict the activity of metformin as an adjuvant for cisplatin-based therapy in non-small cell lung cancer (NSCLC). A549, HCC 827 (TP53 WT), H1299, and H358 (TP53 null) cell lines were used in this study. A549 cells were pre-treated with a sub-lethal dose of cisplatin to induce chemoresistance. The effects of metformin were tested both in vitro and in vivo and related to the ability of cells to accumulate Jarid1b, a histone demethylase involved in cisplatin resistance in different cancers. Metformin sensitized A549 and HCC 827 cells (but not H1299 and H358 cells) to cisplatin in a P53-dependent manner, changing its subcellular localization to the mitochondria. Treatment with a sub-lethal dose of cisplatin increased Jarid1b expression, yet downregulated P53 levels, protecting A549Res cells from metformin-induced chemosensitization to cisplatin and favored a glycolytic phenotype. Treatment with FL3, a synthetic flavagline, sensitized A549Res cells to cisplatin. In conclusion, metformin could potentially be used as an adjuvant for cisplatin-based therapy in NSCLC cells if wild type P53 is present.

We studied a family in which the first-born child, a girl, had developmental delay, facial dysmorphism, and agenesis of the corpus callosum (ACC). The subsequent pregnancy was interrupted as the fetus was found to be also affected by ACC. Both cases were heterozygous for two KDM5B variants predicting p (Ala635Thr) and p (Ser1155Ala fs Ter4) that were shown to be in trans . KDM5B variants have been previously associated with moderate to severe developmental delay/intellectual disability (DD/ID), autism spectrum disorders (ASD), and dysmorphism in a few individuals, but the pathogenetic mechanisms are not clear yet as patients with both monoallelic and biallelic variants have been observed. Interestingly, one individual has previously been reported with ACC and severe ID in association with biallelic KDM5B variants. Together with the observations in this family, this suggests that agenesis of the corpus callosum may be part of the phenotypic spectrum associated with KDM5B variants and that the KDM5B gene should be included in gene panels to clarify the etiology of ACC both in the prenatal and postnatal setting.

KDM5A and KDM5B histone-demethylases are overexpressed in many cancers and have been involved in drug tolerance. Here, we describe that KDM5A, together with KDM5B, contribute to replication stress (RS) response and tolerance. First, they positively regulate RRM2, the regulatory subunit of ribonucleotide reductase. Second, they are required for optimal levels of activated Chk1, a major player of the intra-S phase checkpoint that protects cells from RS. We also found that KDM5A is enriched at ongoing replication forks and associates with both PCNA and Chk1. Because RRM2 is a major determinant of replication stress tolerance, we developed cells resistant to HU, and show that KDM5A/B proteins are required for both RRM2 overexpression and tolerance to HU. Altogether, our results indicate that KDM5A/B are major players of RS management. They also show that drugs targeting the enzymatic activity of KDM5 proteins may not affect all cancer-related consequences of KDM5A/B overexpression., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2021. Published by The Company of Biologists Ltd.)

Epigenetic dysregulation is a hallmark of cancers, and examples of its cancer-associated expression and mutation alterations are rapidly growing. Histone methylation, a process by which methyl groups are transferred to amino acids of histone proteins, is crucial for the epigenetic gene regulation. NSD2 (nuclear receptor-binding SET domain protein 2) and SETMAR are epigenetic regulators for histone methylation. KDM2B, also known as FBXL10, is a histone demethylase that targets histone methylation processes. They are known to be altered in many cancers, but somatic frameshift mutation and expression of these genes remain undetermined in many other subsets of cancers, including high microsatellite instability (MSI-H) colon cancer (CC). In this study, we analyzed mononucleotide repeats in coding sequences of NSD2, KDM2B and SETMAR genes, and found frameshift mutations in 10 %, 2 % and 1 % of CCs with MSI-H, respectively. Of note, there was no frameshift mutation of these genes in microsatellite stable (MSS) CCs. In addition, we discovered that 2 and 2 of 16 CRCs (12.5 % and 12.5 %) harbored intratumoral heterogeneity (ITH) of the NSD2 and KDM2B frameshift mutations, respectively. In the immunohistochemistry for NSD2, intensity of NSD2 immunostaining in MSI-H CC is decreased compared to that in MSS. These results suggest that NSD2 might be altered at multiple levels (frameshift mutation, mutational ITH and expression) in MSI-H CCs, and could be related to MSI-H cancer pathogenesis., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

Aims: Epigenetic and genetic alterations are crucial events in the onset and progression of human cancers including colorectal cancer (CRC). This work aims to probe the relevance of lysine demethylase 5B (KDM5B) to the progression of CRC and the possible molecules involved., Materials and Methods: KDM5B expression in CRC tissues and cells was determined. The association between KDM5B and the prognosis of patients was analyzed. Gain- and loss-of function studies of KDM5B were performed in HT-29 and KDM5B cells to explore the impact of KDM5B on cell behaviors. Expression of CC chemokine ligand 14 (CCL14) in CRC tissues and cells and its correlation with KDM5B were analyzed. Altered expression of CCL14 was introduced in CRC cells, and a Wnt/β-catenin-specific antagonist KYA1797K was induced in cells as well., Key Findings: KDM5B was abundantly expressed while CCL14 was poorly expressed in CRC tissues and cells. High KDM5B expression was relevant to poor prognosis of patients. Downregulation of KDM5B suppressed proliferation and aggressiveness of HT-29 cells, and reduced the growth of xenograft tumors in mice, while upregulation of KDM5B in SW480 cells led to reverse results. KDM5B reduced CCL14 expression through demethylation modification of H3K4me3. Upregulation of CCL14 suppressed colony formation and invasiveness of CRC cells. KDM5B downregulated CCL14 to activate the Wnt/β-catenin. Inhibition of β-catenin by KYA1797K blocked the oncogenic roles of KDM5B in cells and in xenograft tumors., Significance: This study suggested that KDM5B suppresses CCL14 through demethylation modification of H3K4me3, leading to activation of the Wnt/β-catenin and the CRC progression., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Jumonji AT-rich interactive domain 1B(JARID1B) has been shown to be upregulated in many human cancers and plays a critical role in the development of cancers cells. Nevertheless, its functional role in colorectal cancer (CRC) progression is not fully understood., Methods: Herein, JARID1B expression levels were detected in clinical CRC samples by western blotting and qRT-PCR. DLD-1 cells with JARID1B knockdown or overexpression by stably transfected plasmids were used in vitro and in vivo study. Colony formation, 5-ethynyl-20-deoxyuridine (EdU) and Real Time Cellular Analysis (RTCA) assays were used to detect cell proliferation and growth. Transcriptome and CHIP assays were used to examine the molecular biology changes and molecular interaction in these cells. Nude mice was utilized to study the correlation of JARID1B and tumor growth in vivo., Results: Here, we first observed that JARID1B was significantly upregulated in CRC tissue compared to adjacent normal tissues. In CRC patients, JARID1B high expression was positively relation with poor overall survival. Multivariate analyses revealed that high JARID1B expression was an independent predictive marker for the poor prognosis of CRC. In addition, we found that JARID1B promoted CRC cells proliferation by Wnt/β-catenin signaling pathway. Further studies demonstrated CDX2 as a downstream target of JARID1B, and our data demonstrated that CDX2 is crucial for JARID1B -mediated Wnt/β-catenin signaling pathway. Mechanistically, we demonstrated that JARID1B regulated CDX2 expression through demethylation of H3K4me3., Conclusions: CDX2 inhibited by JARID1B-derived H3K4me3 methylation promoted cells proliferation of CRC via Wnt/β-catenin signaling pathway. Therefore, our studies provided a novel insight into the role of JARID1B in CRC cells proliferation and potential new molecular target for treating CRC. Video abstract.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concern was raised about the reliability of the Transwell assay results shown in Figures 3G, 6F, and 7F, which appear to contain image similarities within some of the panels, as detailed here: https://pubpeer.com/publications/7680482DF471CF3FADB2D14154BCFF and here: https://docs.google.com/spreadsheets/d/1r0MyIYpagBc58BRF9c3luWNlCX8VUvUuPyYYXzxWvgY/edit#gid=262337249. In addition, several suspected image similarities were detected within the whole brain images in Figure 7I, and within the Transwell assays of Figure 7G. The journal requested the corresponding author comment on these concerns and provide the raw data. However, the authors were not able to satisfactorily fulfill this request and therefore the Editor-in-Chief decided to retract the article., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The histone lysine demethylase KDM5 family is implicated in normal development and stem cell maintenance by epigenetic modulation of histone methylation status. Deregulation of the KDM5 family has been reported in various types of cancers, including hematological malignancies. However, their transcriptional regulatory roles in the context of leukemia remain unclear. Here, we find that KDM5B is strongly expressed in normal CD34 + hematopoietic stem/progenitor cells and chronic myeloid leukemia (CML) cells. Knockdown of KDM5B in K562 CML cells reduced leukemia colony-forming potential. Transcriptome profiling of KDM5B knockdown K562 cells revealed the deregulation of genes involved in myeloid differentiation and Toll-like receptor signaling. Through the integration of transcriptome and ChIP-seq profiling data, we show that KDM5B is enriched at the binding sites of the GATA and AP-1 transcription factor families, suggesting their collaborations in the regulation of transcription. Even though the binding of KDM5B substantially overlapped with H3K4me1 or H3K4me3 mark at gene promoters, only a small subset of the KDM5B targets showed differential expression in association with the histone demethylation activity. By characterizing the interacting proteins in K562 cells, we discovered that KDM5B recruits protein complexes involved in the mRNA processing machinery, implying an alternative epigenetic action mediated by KDM5B in gene regulation. Our study highlights the oncogenic functions of KDM5B in CML cells and suggests that KDM5B is vital to the transcriptional regulation via multiple epigenetic mechanisms., Competing Interests: Conflict of interest disclosure The authors declare no competing interests., (Copyright © 2020 ISEH -- Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.)

Melanoma cells shift between epigenetic-metabolic states to adapt to stress and, particularly, to drugs. Here, we unraveled the metabolome of an H3K4 demethylase (KDM5B/JARID1B)-driven melanoma cell phenotype that is known to be multidrug resistant. We set up a fast protocol for standardized, highly sensitive liquid chromatography-high resolution mass spectrometry analyzing stably controlled KDM5B expression by RNAi or doxycycline-induced overexpression. Within the KDM5B-dependent metabolome, we found significant and highly specific regulation of 11 intracellular metabolites. Functionally, overexpression of KDM5B in melanoma cells led to broadening of their oxidative metabolism from mainly glutamine-dependent to additionally glucose- and fatty acid-utilizing, upregulation of the pentose phosphate pathway as a source of antioxidant NADPH, and maintenance of a high ratio of reduced to oxidized glutathione. Histone lysine demethylase inhibition (GSK-J1, 2,4-PDCA) decreased colony formation and invasion in three-dimensional models. Thus, targeting KDM5B could represent an alternative way of modulating the metabolome and malignant cell behavior in melanoma., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Objectives: Terminally differentiated stratified squamous epithelial cells play an important role in barrier protection of the skin. The integrity of epidermal cells is maintained by tight regulation of proliferation and differentiation. The aim of this study was to investigate the role of epigenetic regulator H3K4me3 and its demethylase Jarid1b in the control of epithelial cell differentiation., Materials and Methods: RT-qPCR, Western blotting and IHC were used to detect mRNA and protein levels. We analysed cell proliferation by CCK8 assay and cell migration by wound healing assay. ChIP was used to measure H3K4me3 enrichment. A chamber graft model was established for epidermal development., Results: Our studies showed that H3K4me3 was decreased during epidermal differentiation. The H3K4me3 demethylase Jarid1b positively controlled epidermal cell differentiation in vitro and in vivo. Mechanistically, we found that Jarid1b substantially increased the expression of mesenchymal-epithelial transition (MET)-related genes, among which Ovol1 positively regulated differentiation gene expression. In addition, Ovol1 expression was repressed by PI3K-AKT pathway inhibitors and overexpression (O/E) of the PI3K-AKT pathway suppressor Ship1. Knockdown (KD) of Ship1 activated downstream PI3K-AKT pathway and enhanced Ovol1 expression in HaCaT. Importantly, we found that Jarid1b negatively regulated Ship1 expression, but not that of Pten, by directly binding to its promoter to modulate H3K4me3 enrichment., Conclusion: Our results identify an essential role of Jarid1b in the regulation of the Ship1/AKT/Ovol1 pathway to promote epithelial cell differentiation., (© 2019 The Authors. Cell Proliferation Published byJohn Wiley & Sons Ltd.)

Microduplications involving 1q32.1 chromosomal region have been rarely reported in literature. Patients with these microduplications suffer from intellectual disability, developmental delay and a number of dysmorphic features, although no clear karyotype/phenotype correlation has yet been determined. In this case report we describe two monochorionic-diamniotic twins with intellectual disability, abnormality of coordination and dysmorphic features associated with a de novo 280 kb mosaic microduplication of 1q32.1 chromosomal region, identified using a Chromosome Microarray Analysis (CMA) and confirmed by quantitative PCR analysis. The duplicated region encompassed entirely three OMIM genes KDM5B (*605393), KLHL12 (*614522), RABIF (*603417) and involved partially SYT2 (*600104). This unique case report allows to redefine the critical 1q32.1 microduplicated region implicated in the ethiopathogenesis of intellectual disability and developmental delay. Furthermore, it suggests that KDM5B gene can have a pivotal role in the development of neurodevelopmental disorders through its demethylase activity., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Aim: This study aimed to investigate the possible functions of interaction between JARID1B and miR-137 in ALL., Methods: The levels of H3K4me3 and H3K4me2 and the expression of JARID1B and miR-137 were analyzed in six ALL cell lines and 30 ALL patients. The effects of miR-137 and JARID1B on cell proliferation and apoptosis were investigated by silencing or promoting the respective genes. The interaction between miR-137 and JARID1B was confirmed by double-luciferase report assay., Results: The histone H3K4 expressions and miR-137 expression were lower in 30 ALL patients and in six ALL cell lines, while the expression of JARID1B was elevated. A negative correlation was observed between JARID1B and miR-137. Over-expression of miR-137 led to decreasing cell proliferation and increasing apoptosis in MOLT-4 and BALL-1 cells. MiR-137 inhibitor up-regulated JARID1B in these two cell lines, while promoted proliferation in BALL-1 cells only. Dual-luciferase report assay suggested that JARID1B was a direct target of miR-137 in ALL cell lines., Conclusions: The expression of miR-137 was declined in ALL, and JARID1B was directly repressed by miR-137. Aberrant JARID1B expression could result in abnormal histone methylation, which might be one cause of ALL., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Reprogramming somatic cells to pluripotency by Oct4, Sox2, Klf4, and Myc represent a paradigm for cell fate determination. Here, we report a combination of Jdp2, Jhdm1b, Mkk6, Glis1, Nanog, Essrb, and Sall4 (7F) that reprogram mouse embryonic fibroblasts or MEFs to chimera competent induced pluripotent stem cells (iPSCs) efficiently. RNA sequencing (RNA-seq) and ATAC-seq reveal distinct mechanisms for 7F induction of pluripotency. Dropout experiments further reveal a highly cooperative process among 7F to dynamically close and open chromatin loci that encode a network of transcription factors to mediate reprogramming. These results establish an alternative paradigm for reprogramming that may be useful for analyzing cell fate control., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Background : KDM5 enzymes are H3K4 specific histone demethylases involved in transcriptional regulation and DNA repair. These proteins are overexpressed in different kinds of cancer, including breast, prostate and bladder carcinomas, with positive effects on cancer proliferation and chemoresistance. For these reasons, these enzymes are potential therapeutic targets. Methods : In the present study, we analyzed the effects of three different inhibitors of KDM5 enzymes in MCF-7 breast cancer cells over-expressing one of them, namely KDM5B/JARID1B. In particular we tested H3K4 demethylation (western blot); radio-sensitivity (cytoxicity and clonogenic assays) and damage accumulation (COMET assay and kinetics of H2AX phosphorylation). Results : we show that all three compounds with completely different chemical structures can selectively inhibit KDM5 enzymes and are capable of increasing sensitivity of breast cancer cells to ionizing radiation and radiation-induced damage. Conclusions : These findings confirm the involvement of H3K4 specific demethylases in the response to DNA damage, show a requirement of the catalytic function and suggest new strategies for the therapeutic use of their inhibitors.

Objective: Endometrial cancer (EC) is one of the most common female reproductive system tumors. In this study, we explored the clinical significance of Histone demethylase KDM5B gene and its effects on paclitaxel (PTX) sensitivity in EC., Method: First, we found that KDM5B expression significantly higher in EC tissues and cell lines. The elevated KDM5B expression was associated with high pathological grade and low PTX sensitivity. The functional role of KDM5B in PTX-resistant Ishikawa-R and HEC1A-R cells were examined by gene silencing experiments., Results: Knockdown of KDM5B resulted in the re-sensitization towards paclitaxel in both resistant cell lines. In addition, we also identified that microRNA-29c-3p (a tumor suppressor) was significantly lower in the EC cells and linked to the low PTX sensitivity of EC. The up-regulation of miR-29c-3p using exogenous mimic molecules markedly increased PTX sensitivity in both cell lines and reduced expression of KDM5B while the inhibitor of miR-29-3p resulted in the opposite effects. Notably, we also demonstrated that the level of miR-29c-3p was inversely correlated to the invasive, colony-forming abilities and PTX resistance in both cell lines. We also identified that miR-29c-3p has a binding site in the 3'UTR of the KDM5B gene, establishing a link of this signaling axis. In conclusion, high-expression of KDM5B is associated with the poor response to PTX in EC patients. Silencing of KDM5B led to the reversal of PTX resistance through miR-29c-3p/KDM5B pathway in EC., Conclusion: Our findings provide new insights into the mechanism by which EC cells acquire paclitaxel resistance and potential this signaling as a theronostic marker for this malignancy., (Copyright © 2019. Published by Elsevier B.V.)

JARID1B/KDM5B histone demethylase's mRNA is markedly overexpressed in breast cancer tissues and cell lines and the protein has been shown to have a prominent role in cancer cell proliferation and DNA repair. However, the mechanism of its post-transcriptional regulation in cancer cells remains elusive. We performed a computational analysis of transcriptomic data from a set of 103 breast cancer patients, which, along with JARID1B upregulation, showed a strong downregulation of 2 microRNAs (miRNAs), mir-381 and mir-486, potentially targeting its mRNA. We showed that both miRNAs can target JARID1B 3'UTR and reduce luciferase's activity in a complementarity-driven repression assay. Moreover, MCF7 breast cancer cells overexpressing JARID1B showed a strong protein reduction when transfected with mir-486. This protein's decrease is accompanied by accumulation of DNA damage, enhanced radiosensitivity and increase of BRCA1 mRNA, 3 features previously correlated with JARID1B silencing. These results enlighten an important role of a miRNA's circuit in regulating JARID1B's activity and suggest new perspectives for epigenetic therapies., (© 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Hyperactivated AKT kinase due to loss of its negative regulator PTEN influences many aspects of cancer biology, including chromatin. AKT primarily regulates acetyl-CoA production and phosphorylates many histone-modulating enzymes, resulting in their activation or inhibition. Therefore, understanding the therapeutic impact of AKT inhibition on chromatin-related events is essential. Here, we report that AKT inhibition in prostate-specific PTEN knockout mice significantly induces di- and trimethylation of H3K4 with concomitant reduction in H3K9 acetylation. Mechanistically, we observed that AKT inhibition reduces expression of the H3K4 methylation-specific histone demethylases KDM5 family, especially KDM5B expression at transcriptional levels. Furthermore, we observed that AKT negatively regulates miR-137 levels, which transcriptionally represses KDM5B expression. Overexpression of miR-137 significantly reduced KDM5B and increased H3K4 methylation levels but failed to change AKT phosphorylation. Overall, we observed that AKT transcriptionally regulates KDM5B mainly via repression of miR-137. Our data identify a mechanism by which AKT kinase modulates the prostate cancer epigenome through regulating H3K4 methylation. Additional studies on AKT inhibition-mediated induction of H3K4 methylation will help in designing strategies to enhance the therapeutic efficacy of PI3K/AKT inhibitors., (©2018 American Association for Cancer Research.)

Aims: Accumulation of reactive oxygen species (ROS) promotes vascular disease in obesity, but the underlying molecular mechanisms remain poorly understood. The adaptor p66Shc is emerging as a key molecule responsible for ROS generation and vascular damage. This study investigates whether epigenetic regulation of p66Shc contributes to obesity-related vascular disease., Methods and Results: ROS-driven endothelial dysfunction was observed in visceral fat arteries (VFAs) isolated from obese subjects when compared with normal weight controls. Gene profiling of chromatin-modifying enzymes in VFA revealed a significant dysregulation of methyltransferase SUV39H1 (fold change, -6.9, P < 0.01), demethylase JMJD2C (fold change, 3.2, P < 0.01), and acetyltransferase SRC-1 (fold change, 5.8, P < 0.01) in obese vs. control VFA. These changes were associated with reduced di-(H3K9me2) and trimethylation (H3K9me3) as well as acetylation (H3K9ac) of histone 3 lysine 9 (H3K9) on p66Shc promoter. Reprogramming SUV39H1, JMJD2C, and SRC-1 in isolated endothelial cells as well as in aortas from obese mice (LepOb/Ob) suppressed p66Shc-derived ROS, restored nitric oxide levels, and rescued endothelial dysfunction. Consistently, in vivo editing of chromatin remodellers blunted obesity-related vascular p66Shc expression. We show that SUV39H1 is the upstream effector orchestrating JMJD2C/SRC-1 recruitment to p66Shc promoter. Indeed, SUV39H1 overexpression in obese mice erased H3K9-related changes on p66Shc promoter, while SUV39H1 genetic deletion in lean mice recapitulated obesity-induced H3K9 remodelling and p66Shc transcription., Conclusion: These results uncover a novel epigenetic mechanism underlying endothelial dysfunction in obesity. Targeting SUV39H1 may attenuate oxidative transcriptional programmes and thus prevent vascular disease in obese individuals.

Histone lysine methylation influences processes such as gene expression and DNA repair. Thirty Jumonji C (JmjC) domain-containing proteins have been identified and phylogenetically clustered into seven subfamilies. Most JmjC domain-containing proteins have been shown to possess histone demethylase activity toward specific histone methylation marks. One of these subfamilies, the KDM5 family, is characterized by five conserved domains and includes four members. Interestingly, de novo loss-of-function and missense variants in KDM5B were identified in patients with intellectual disability (ID) and autism spectrum disorder (ASD) but also in unaffected individuals. Here, we report two novel de novo splice variants in the KDM5B gene in three patients with ID and ASD. The c.808 + 1G > A variant was identified in a boy with mild ID and autism traits and is associated with a significant reduced KDM5B mRNA expression without alteration of its H3K4me3 pattern. In contrast, the c.576 + 2T > C variant was found in twins with global delay in developmental milestones, poor language and ASD. This variant causes the production of an abnormal transcript which may produce an altered protein with the loss of the ARID1B domain with an increase in global gene H3K4me3. Our data reinforces the recent observation that the KDM5B haploinsufficiency is not a mechanism involved in intellectual disability and that KDM5B disorder associated with LOF variants is a recessive disorder. However, some variants may also cause gain of function, and need to be interpreted with caution, and functional studies should be performed to identify the molecular consequences of these different rare variants., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Members of the KDM5 histone H3 lysine 4 demethylase family are associated with therapeutic resistance, including endocrine resistance in breast cancer, but the underlying mechanism is poorly defined. Here we show that genetic deletion of KDM5A/B or inhibition of KDM5 activity increases sensitivity to anti-estrogens by modulating estrogen receptor (ER) signaling and by decreasing cellular transcriptomic heterogeneity. Higher KDM5B expression levels are associated with higher transcriptomic heterogeneity and poor prognosis in ER + breast tumors. Single-cell RNA sequencing, cellular barcoding, and mathematical modeling demonstrate that endocrine resistance is due to selection for pre-existing genetically distinct cells, while KDM5 inhibitor resistance is acquired. Our findings highlight the importance of cellular phenotypic heterogeneity in therapeutic resistance and identify KDM5A/B as key regulators of this process., (Copyright © 2018 Elsevier Inc. All rights reserved.)

BACKGROUND Lysine-specific demethylase 5B (KDM5B) is overexpressed in several types of cancer. However, the clinical significance of KDM5B expression in hepatocellular carcinoma (HCC) remains unclear. The aims of the present study were to examine the functional effects of KDM5B in the Hep3B cell line, the expression levels of KDM5B in human HCC tissues, and the association between KDM5B expression and clinical outcome in patients with HCC. MATERIAL AND METHODS Immunohistochemistry (IHC) and quantitative real-time polymerase chain reaction (qRT-PCR) were used to examine the expression levels of KDM5B in HCC tissues and adjacent normal liver tissues. In the HCC cell line, Hep3B, the effects of KDM5B on cell proliferation and migration, and KDM5B small interfering RNA (siRNA) were used to study KDM5B knockdown. Univariate and multivariate analysis assessed the prognostic role of KDM5B in HCC patients. Kaplan-Meier analysis and the log-rank test evaluated clinical outcomes. RESULTS In the HCC cell line, Hep3B, KDM5B expression promoted promote tumor cell proliferation and colony formation. Increased expression of KDM5B in HCC tissues, compared with adjacent normal liver tissues, and was associated with larger tumor size, advanced TNM stage, and reduced overall survival in patients with HCC. Multivariate analysis identified KDM5B expression as an independent prognostic factor. CONCLUSIONS Increased expression of KDM5B was significantly correlated with poorer prognosis in patients with patients with HCC, indicating the possible potential of KDM5B as a novel clinical biomarker and therapeutic target.

The development of small-molecule tyrosine kinase inhibitors (TKI) specific for epidermal growth factor receptors (EGFR) with activating mutations has led to a new paradigm in the treatment of non-small cell lung cancer (NSCLC) patients. However, most patients eventually develop resistance. Hypoxia is a key microenvironmental stress in solid tumors that is associated with poor prognosis due, in part, to acquired resistance to conventional therapy. This study documents that long-term, moderate hypoxia promotes resistance to the EGFR TKI, gefitinib, in the NSCLC cell line HCC827, which harbors an activating EGFR mutation. Following hypoxic growth conditions, HCC827 cells treated with gefitinib upregulated N-cadherin, fibronectin, and vimentin expression and downregulated E-cadherin, characteristic of an epithelial-mesenchymal transition (EMT), which prior studies have linked to EGFR TKI resistance. Mechanistically, knockdown of the histone demethylases, LSD1 and PLU-1, prevented and reversed hypoxia-induced gefitinib resistance, with inhibition of the associated EMT, suggesting that LSD1 and PLU-1 play key roles in hypoxia-induced gefitinib resistance and EMT. Moreover, hypoxia-treated HCC827 cells demonstrated more aggressive tumor growth in vivo compared with cells grown in normoxia, but inhibition of LSD1 function by shRNA-mediated knockdown or by the small-molecular inhibitor SP2509 suppressed tumor growth and enhanced gefitinib response in vivo These results suggest that hypoxia is a driving force for acquired resistance to EGFR TKIs through epigenetic change and coordination of EMT in NSCLC. This study suggests that combination of therapy with EGFR TKIs and LSD1 inhibitors may offer an attractive therapeutic strategy for NSCLCs. Mol Cancer Res; 16(10); 1458-69. ©2018 AACR ., (©2018 American Association for Cancer Research.)

Background: Lung cancer is the leading cause of cancer death worldwide. Recently, epigenetic dysregulation has been known to promote tumor progression and therefore may be a therapeutic target for anticancer therapy. JARID1B, a member of histone demethylases, has been found to be related to tumorigenesis in certain kinds of cancers. However, its biological roles in non-small cell lung cancer (NSCLC) remain largely unclear., Methods: We firstly examined the expression of JARID1B in surgical specimens and six NSCLC cell lines. Then, we evaluated the relationship between JARID1B expression and clinicopathologic parameters in 72 NSCLC patients, thereby established its prognostic importance. We subsequently studied the functional roles of JARID1B in tumorigenesis to verify its clinicopathologic significance., Results: Our results showed that JARID1B was overexpressed in NSCLC cells and JARID1B overexpression was associated with tumor size, lymph node metastasis, advanced stages, and poor overall survival in NSCLC patients. JARID1B overexpression resulted in increased cell proliferation and formation of tumorspheres and correlated positively with the expression of cancer stem cells (CSCs) and epithelial-mesenchymal transition (EMT) markers, while the c-Met signaling pathway was actively involved. It also correlated with the strength of resistance to cisplatin and doxorubicin. On the contrary, downregulation of JARID1B expression by applying shRNA or JARID1B inhibitor PBIT reversed these phenomena., Conclusions: JARID1B worsens prognosis of NSCLC patients by promotion of tumor aggressiveness through multiple biological facets which were associated with activation of the c-Met signaling, and can be a novel prognostic biomarker and therapeutic target for NSCLC.

Chemotherapy is the main treatment for human cancers including gastric cancer. However, in response to chemotherapeutic drugs, tumor cells can develop drug resistance by reprogramming intracellular metabolic and epigenetic networks to maintain their intrinsic homeostasis. Previously, we have established cisplatin-resistant gastric cancer cells as a drug resistant model, and elucidated the XRCC1 as the core DNA repair mechanism of drug resistance. This study investigated the regulation of XRCC1 by lysine demethylase 5B (KDM5B) in drug resistance. We found that the methylation level of H3K4 decreased significantly in drug-resistant cells. The chemical inhibitor of H3K4 demethylases, JIB-04, restored the methylation of H3K4 and blocked the co-localization of XRCC1 and γH2AX, eventually improved drug sensitivity. We further found that the expression level of KDM5B increased significantly in drug-resistant cells. Knockdown of KDM5B increased the methylation level of H3K4 and blocked the localization of XRCC1 to the DNA damage site, leads to increased drug sensitivity. In the sensitive cells, overexpression of KDM5B suppressed H3K4 methylation levels, which resulted to resistance to cisplatin. Moreover, we found that the posttranslational modification of KDM5B is responsible for its high expression in drug-resistant cells. Through mass spectrometry screening and co-immunoprecipitation validation, we found that the molecular chaperone HSP90 forms a complex with KDM5B in drug resistance cells. Interestingly, HSP90 inhibitor 17-AAG induced KDM5B degradation in a time-and-dose-dependent manner, indicating that HSP90 protected KDM5B from protein degradation. Targeting inhibition of HSP90 and KDM5B reversed drug resistance both in vitro and in vivo . Taken together, molecular chaperon HSP90 interacted with KDM5B to protect it from ubiquitin-dependent proteasomal degradation. Increased KDM5B demethylated H3K4 and facilitated the recruitment of XRCC1 to repair damaged DNA. Therefore, inhibition of HSP90 or KDM5B represented a novel approach to reverse chemoresistance in human cancers., Competing Interests: Competing Interests: The authors have declared that no competing interest exists.

JARID1B has been proven to be upregulated in many human malignancies and is correlated with tumor progression. However, its expression and clinical significance in osteosarcoma are still unclear. Thus, the aim of this study was to explore the effects of JARID1B in osteosarcoma tumorigenesis and development. In this study, we found that the expression levels of JARID1B in osteosarcoma tissues were significantly higher than those in corresponding noncancerous bone tissues. In addition, JARID1B upregulation occurred more frequently in osteosarcoma specimens from patients with a poor prognosis. After JARID1B transfection in osteosarcoma cells, cell proliferation was significantly promoted in vitro and in vivo. On the contrary, knockdown of JARID1B inhibited cell proliferation in vitro and tumor growth in vivo. JARID1B can also decrease the G 0 /G 1 phase cell numbers and increase the S and G₂/M phase cell numbers. We further demonstrated that JARID1B regulates cyclin D1 expression through H3K27me3. These findings indicate that JARID1B may act not only as a novel diagnostic and prognostic marker but also as a potential target for molecular therapy in osteosarcoma.

Persistent infection by high-risk human papillomaviruses (HPVs) is associated with the development of cervical cancer and a subset of anogenital and head and neck squamous cell carcinomas. Abnormal expression of cellular microRNAs (miRNAs) plays an important role in the development of cancer, including HPV-related tumors. In this study, we demonstrated that miR-146a-5p was down-regulated by E6 and, less efficiently, by E7 of high-risk HPV16 in keratinocytes and the presence of low levels of this miRNA in cervical carcinoma cell lines and in high-risk HPV-positive cervical specimens. Down-regulation of miR-146a-5p was mediated at least in part by the transcription repressor c-MYC, through binding sites in the miR-146a promoter. Overexpression of miR-146a-5p significantly inhibited proliferation and migration of keratinocytes and cervical cancer cells. The histone demethylase KDM2B was validated as a new direct target of miR-146a-5p and two putative binding sites for miR-146a-5p were identified in its 3'UTR sequence. Western blot analysis and immunohistochemistry showed that KDM2B was overexpressed in HPV16 E6/E7-positive keratinocytes, in cervical cancer cell lines, and in a subset of invasive cervical carcinomas and HPV-positive laryngeal squamous cell carcinomas. In these tumors, KDM2B overexpression was associated with c-MYC copy number gain. In vitro, silencing of KDM2B inhibited proliferation of cervical cancer cells. In conclusion, this study identified a novel player, the hystone demethylase KDM2B, in HPV-mediated tumorigenesis. E6 and, less efficiently, E7 of high-risk HPV16 up-regulated KDM2B expression in human keratinocytes through a pathway involving overexpression of c-MYC, which in turn downregulated miR-146a-5p.

Objective: Acute lymphocytic leukemia (ALL) is a multi-factorial blood disease with unknown pathogenesis. Histone H3K4 methylation was significantly reduced in ALL patients, whereas jumonji AT-rich interactive domain 1B (JARID1B) was the specific demethylase of H3K4me. This study explores the expression level of JARID1B in ALL patients and down-regulated JARID1B expression in ALL cells to explore the function of JARID1B in ALL., Patients and Methods: JARID1B mRNA expression level in ALL patients was detected by Real-time PCR. The peripheral blood mononuclear cells from healthy volunteers were selected as control. JARID1B shRNA was transfected with MOLT-4 cells and BALL-1 cells. JARID1B protein expression and H3K4me2 and H3K4me3 levels were detected by Western blot assay. Cell proliferation was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Cell apoptosis and cell cycle were determined by flow cytometry. Bcl-2, Bax, Procaspase 3, and cyclin P21 expressions were evaluated by Western blot assay., Results: JARID1B mRNA expression in primary bone marrow cells from ALL patients was significantly higher than that of healthy volunteers (p<0.05). The levels of histone H3K4me3 and H3K4me2 were up-regulated after JARID1B shRNA transfection. JARID1B shRNA significantly inhibited the proliferation of MOLT-4 and BALL-1 cells, induced apoptosis, and blocked cell cycle in G0/G1 phase compared with the control group (p<0.05)., Conclusions: JARID1B is highly expressed in ALL. Down-regulating its expression inhibited leukemia cell proliferation, promoted apoptosis, and blocked cell cycle in G0/G1 phase through histone H3K4 methylation. JARID1B is an oncogene in ALL.

Background: Histone demethylase JARID1B plays several context dependent roles in epigenetic regulation of cellular differentiation in normal development and is highly expressed in multiple human cancers. The protein is a strong transcriptional repressor capable of downregulating numerous genes. There are three splicing isoforms of JARID1B, however the links between the protein structure and function are not clear. The expression pattern of JARID1B in human melanoma seems to be different from observed in other cancers. Moreover, up to now no data on the impact of JARID1B expression in cutaneous melanoma on the patients' prognosis have been reported., Methods: We investigated immunohistochemically the association of intratumoral expression of total JARID1B protein and its RBP2-H1 isoform in primary and metastatic melanomas with prognosis for the patients., Results: Expression of both total JARID1B protein and its RBP2-H1 variant was found in all the melanomas investigated. Our results indicate, however, that only high (above 90% of the cells) intratumoral expression of RBP2-H1 can be considered prognostic factor associated with worse overall survival of the patients., Conclusions: Such results if considered together with data demonstrating a switch to enhanced expression of RBP2-H1 at early stages of malignant transformation of melanocytes are in agreement with hypothetical crucial role of JARID1B in the course of melanoma development and progression and suggest that altered splicing of JARID1B may be important factor increasing melanoma aggressiveness.

RNA-binding proteins (RBPs), in addition to their functions in cellular homeostasis, play important roles in lineage specification and maintaining cellular identity. Despite their diverse and essential functions, which touch on nearly all aspects of RNA metabolism, the roles of RBPs in somatic cell reprogramming are poorly understood. Here we show that the DEAD-box RBP DDX5 inhibits reprogramming by repressing the expression and function of the non-canonical polycomb complex 1 (PRC1) subunit RYBP. Disrupting Ddx5 expression improves the efficiency of iPSC generation and impedes processing of miR-125b, leading to Rybp upregulation and suppression of lineage-specific genes via RYBP-dependent ubiquitination of H2AK119. Furthermore, RYBP is required for PRC1-independent recruitment of OCT4 to the promoter of Kdm2b, a histone demethylase gene that promotes reprogramming by reactivating endogenous pluripotency genes. Together, these results reveal important functions of DDX5 in regulating reprogramming and highlight the importance of a Ddx5-miR125b-Rybp axis in controlling cell fate., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Autism spectrum disorder (ASD) is one of the most highly heritable neuropsychiatric disorders, but underlying molecular mechanisms are still unresolved due to extreme locus heterogeneity. Leveraging meaningful endophenotypes or biomarkers may be an effective strategy to reduce heterogeneity to identify novel ASD genes. Numerous lines of evidence suggest a link between hyperserotonemia, i.e., elevated serotonin (5-hydroxytryptamine or 5-HT) in whole blood, and ASD. However, the genetic determinants of blood 5-HT level and their relationship to ASD are largely unknown., Methods: In this study, pursuing the hypothesis that de novo variants (DNVs) and rare risk alleles acting in a recessive mode may play an important role in predisposition of hyperserotonemia in people with ASD, we carried out whole exome sequencing (WES) in 116 ASD parent-proband trios with most (107) probands having 5-HT measurements., Results: Combined with published ASD DNVs, we identified USP15 as having recurrent de novo loss of function mutations and discovered evidence supporting two other known genes with recurrent DNVs ( FOXP1 and KDM5B ). Genes harboring functional DNVs significantly overlap with functional/disease gene sets known to be involved in ASD etiology, including FMRP targets and synaptic formation and transcriptional regulation genes. We grouped the probands into High-5HT and Normal-5HT groups based on normalized serotonin levels, and used network-based gene set enrichment analysis (NGSEA) to identify novel hyperserotonemia-related ASD genes based on LoF and missense DNVs. We found enrichment in the High-5HT group for a gene network module (DAWN-1) previously implicated in ASD, and this points to the TGF-β pathway and cell junction processes. Through analysis of rare recessively acting variants (RAVs), we also found that rare compound heterozygotes (CHs) in the High-5HT group were enriched for loci in an ASD-associated gene set. Finally, we carried out rare variant group-wise transmission disequilibrium tests (gTDT) and observed significant association of rare variants in genes encoding a subset of the serotonin pathway with ASD., Conclusions: Our study identified USP15 as a novel gene implicated in ASD based on recurrent DNVs. It also demonstrates the potential value of 5-HT as an effective endophenotype for gene discovery in ASD, and the effectiveness of this strategy needs to be further explored in studies of larger sample sizes.

Aims: Aberrant expression of miRNAs exert the critical roles in carcinogenesis, including cervical cancer. Recent study corroborated the down-regulation of miR424-5p in uterine cervix adenocarcinoma. This research aimed to investigate the function and underlying mechanisms of miR424-5p in cervical cancer cell growth., Main Methods: Tissues samples were collected from patients with cervical cancer and healthy control. The expression levels of miR424-5p were determined by qRT-PCR. After transfection with miR424-5p mimics or inhibitor, cervical cancer cell proliferation and apoptosis were evaluated by WST-1 and flow cytometry assay, respectively. The underlying mechanism involved in aforementioned processes was also explored., Key Findings: Expression of miR424-5p was notably decreased in cervical cancer tissues and cells. Overexpression of miR424-5p restrained cell proliferation and promoted cell apoptosis, but with little function in miR424-5p inhibitor-treated groups. Furthermore, KDM5B was identified as a direct target of miR424-5p as the evidence that miR-424-5p inhibited KDM5B expression and luciferase activity of KDM5B 3'-UTR. Here, KDM5B elevation majorly reversed miR424-5p-triggered inhibition in cell proliferation and increase in cell apoptosis. Moreover, silencing KDM5B expression also restrained cell growth. Additionally, miR424-5p overexpression inhibited the expression of Notch1 and Notch2, which was obviously rescued after KDM5B up-regulation. Simultaneously, blocking KDM5B also attenuated the activation of Notch pathway. Importantly, treatment with Notch agonist Jagged1 antagonized miR424-5p-mediated suppression on cell growth., Significance: This research suggests that miR424-5p may act as a novel anti-oncogene in cervical cancer by blocking cell growth through targeting KDM5B-Notch pathway. Accordingly, our study will support a promising therapeutic strategy against cervical carcinoma., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Histone methylation is one of the most important chromatin posttranslational modifications. It has a range of influences on nuclear functions including epigenetic inheritance, transcriptional regulation and the maintenance of genome integrity. Changes in histone methylation status take part in various physiological and pathological processes. KDM5B (lysine demethylase 5B, also called JARID1B or PLU-1) encodes the histone H3 lysine4 (H3K4) demethylase and exhibits a strong transcriptional repression activity. KDM5B plays a role in cell differentiation, stem cell self-renewal and other developmental progresses. Recent studies showed that KDM5B expression was increased in breast, bladder, lung, prostate and many other tumors and promotes tumor initiation, invasion and metastasis. Given its association with tumor progression and prognosis of cancer patients, KDM5B was proposed to be a novel target for the prevention and treatment of human cancers. In this review, we will summarize recent advances in our understanding of the regulation and function of KDM5B in development and cancer.

Increasing evidence suggests that miR-194 is down-regulated in esophageal squamous cell carcinoma tumor tissue. However, the role and underlying mechanism of miR-194 in esophageal squamous cell carcinoma have not been well defined. We used DIANA, TargetScan and miRanda to perform target prediction analysis and found KDM5B is a potential target of miR-194. Based on these findings, we speculated that miR-194 might play a role in esophageal squamous cell carcinoma development and progression by regulation the expression of KDM5B. We detected the expression of miR-194 and KDM5B by quantitative real-time reverse transcription PCR (qRT-PCR) and Western blot assays, respectively, and found down-regulation of miR-194 and up-regulation of KDM5B existed in esophageal squamous cell carcinoma cell lines. By detecting proliferation, invasion and apoptosis of TE6 and TE14 cells transfected with miR-194 mimics or mimic control, miR-194 was found to inhibit proliferation and invasion and promote apoptosis of esophageal squamous cell carcinoma cells. miR-194 was further verified to regulate proliferation, apoptosis and invasion of esophageal squamous cell carcinoma cells by directly targeting KDM5B. Furthermore, animal studies were performed and showed that overexpression of miR-194 inhibited the growth of esophageal squamous cell carcinoma tumors in vivo. These results confirmed our speculation that miR-194 targets KDM5B to inhibit esophageal squamous cell carcinoma development and progression. These findings offer new clues for esophageal squamous cell carcinoma development and progression and novel potential therapeutic targets for esophageal squamous cell carcinoma., (© 2016 by the Society for Experimental Biology and Medicine.)

The complexity by which cells regulate gene and protein expression is multifaceted and intricate. Regulation of 3' untranslated region (UTR) processing of mRNA has been shown to play a critical role in development and disease. However, the process by which cells select alternative mRNA forms is not well understood. We discovered that the Saccharomyces cerevisiae lysine demethylase, Jhd2 (also known as KDM5), recruits 3'UTR processing machinery and promotes alteration of 3'UTR length for some genes in a demethylase-dependent manner. Interaction of Jhd2 with both chromatin and RNA suggests that Jhd2 affects selection of polyadenylation sites through a transcription-coupled mechanism. Furthermore, its mammalian homolog KDM5B (also known as JARID1B or PLU1), but not KDM5A (also known as JARID1A or RBP2), promotes shortening of CCND1 transcript in breast cancer cells. Consistent with these results, KDM5B expression correlates with shortened CCND1 in human breast tumor tissues. In contrast, both KDM5A and KDM5B are involved in the lengthening of DICER1 . Our findings suggest both a novel role for this family of demethylases and a novel targetable mechanism for 3'UTR processing.

Objective: MicroRNAs play critical roles in regulating gene expression and various cellular processes in human cancer malignant progression. The aim of the present study was to examine the expression pattern of miR-194 in gastric cancer (GC) and its biological role in tumor progression., Materials and Methods: Using quantitative RT-PCR, we detected miR-194 expression in GC cell lines and primary tumor tissues. The proliferation, migration, and invasion assays were performed to investigate the effect of miR-194 on the GC cells. The target of miR-194 was predicted by TargetScan and confirmed by luciferase reporter assay. KDM5B expression was detected by Western blot., Results: miR-194 was significantly down-regulated in GC tissues and cell lines. Over-expression of miRNA-194 could inhibit GC cell proliferation, migration, and invasion in vitro. Also, miR-194 inhibited tumor growth and progression in vivo. Dual luciferase-based reporter assay indicated direct regulation of KDM5B by miR-194., Conclusions: Our findings suggested that miR-194 directly targeted KDM5B and thereby acted as a tumor promoter in GC progression.

Previous studies have suggested that jumonji AT-rich interactive domain 1B (JARID1B) plays an important role in the genesis of some types of cancer, and it is therefore considered to be an important drug target protein. Although the expression of JARID1B has been researched in some types of cancer, little is known about JARID1B expression in glioma and its function in the tumorigenesis of gliomas. In the present study, we examined the expression of JARID1B in glioma. In addition, RT-PCR, western blot analysis and immunohistochemical analysis were performed using glioma tissue samples and the results revealed that JARID1B expression increased according to the histological grade of glioma. However, in the normal brain tissue samples JARID1B expression was barely detected. Kaplan‑Meier analysis revealed that higher JARID1B expression in patients with glioma was associated with a poorer prognosis. The overexpression of JARID1B stimulated the proliferation and migration of glioma cells as well as sphere formation, whereas suppressing the expression of JARID1B produced opposite effects. The overexpression of JARID1B increased the tumorigenicity of glioma cells in vivo in a nude mouse xenograft model of glioma. Moreover, the activation of phosphorylated (p-)Smad2 contributes to JARID1B-induced oncogenic activities. These findings suggest that JARID1B is involved in the pathogenesis of glioma, and that the downregulation of JARID1B in glioma cells may be a therapeutic target for the treatment of patients with glioma.

Upregulated expression of histone H3K4 demethylase JARID1B has been found in several types of human cancer, but the expression pattern of this protein in benign naevi and human cutaneous melanomas seems to differ from that described for other tumors. We demonstrate that the apparent contradiction may be because of the fact that the malignant transformation of melanocytes is associated not so much with a general enhancement of a total expression of JARID1B but rather with a change in relative expression levels of individual splicing variants of the protein. Our data indicate that parallel immunohistochemical assays of the expression levels of all the isoforms and of the RBP2-H1 variant of JARID1B may be an efficient technique of differentiating between benign naevi and melanomas.

Background: Triple negative breast cancers (TNBC) possess cell dedifferentiation characteristics, carry out activities connate to those of cancer stem cells (CSCs) and are associated with increased metastasis, as well as, poor clinical prognosis. The regulatory mechanism of this highly malignant phenotype is still poorly characterized. Accruing evidence support the role of non-coding RNAs (ncRNAs) as potent regulators of CSC and metastatic gene expression, with their dysregulation implicated in tumorigenesis and disease progression., Methods: In this study, we investigated TNBC metastasis, metastasis-associated genes and potential inhibitory mechanisms using bioinformatics, tissue microarray analyses, immunoblotting, polymerase chain reaction, loss and gain of gene function assays and comparative analyses of data obtained., Results: Compared with other breast cancer types, the highly metastatic MDA-MB-231 cells concurrently exhibited increased expression levels of Lysine-specific demethylase 5B protein (KDM5B) and long non-coding RNA (lncRNA), MALAT1, suggesting their functional association. KDM5B-silencing in the TNBC cells correlated with the upregulation of hsa-miR-448 and led to suppression of MALAT1 expression with decreased migration, invasion and clonogenic capacity in vitro, as well as, poor survival in vivo. This projects MALAT1 as a mediator of KDM5B oncogenic potential and highlights the critical role of this microRNA, lncRNA and histone demethylase in cancer cell motility and metastatic colonization. Increased expression of KDM5B correlating with disease progression and poor clinical outcome in breast cancer was reversed by hsa-miR-448., Conclusions: Our findings demonstrate the critical role of KDM5B and its negative regulator hsa-miR-448 in TNBC metastasis and progression. Hsa-miR-448 disrupting KDM5B-MALAT1 signalling axis and associated activities in TNBC cells, projects it as a putative therapeutic factor for selective eradication of TNBC cells. Graphical abstract KDM5B, MALAT1 and hsa-miR-448 are active looped components of the epigenetic poculo mortis in aggressive breast cancer.

Impaired function of the Ikaros (IKZF1) protein is associated with the development of high-risk B-cell precursor acute lymphoblastic leukemia (B-ALL). The mechanisms of Ikaros tumor suppressor activity in leukemia are unknown. Ikaros binds to the upstream regulatory elements of its target genes and regulates their transcription via chromatin remodeling. Here, we report that Ikaros represses transcription of the histone H3K4 demethylase, JARID1B (KDM5B). Transcriptional repression of JARID1B is associated with increased global levels of H3K4 trimethylation. Ikaros-mediated repression of JARID1B is dependent on the activity of the histone deacetylase, HDAC1, which binds to the upstream regulatory element of JARID1B in complex with Ikaros. In leukemia, JARID1B is overexpressed, and its inhibition results in cellular growth arrest. Ikaros-mediated repression of JARID1B in leukemia is impaired by pro-oncogenic casein kinase 2 (CK2). Inhibition of CK2 results in increased binding of the Ikaros-HDAC1 complex to the promoter of JARID1B, with increased formation of trimethylated histone H3 lysine 27 and decreased histone H3 Lys-9 acetylation. In cases of high-risk B-ALL that carry deletion of one Ikaros (IKZF1) allele, targeted inhibition of CK2 restores Ikaros binding to the JARID1B promoter and repression of JARID1B. In summary, the presented data suggest a mechanism through which Ikaros and HDAC1 regulate the epigenetic signature in leukemia: via regulation of JARID1B transcription. The presented data identify JARID1B as a novel therapeutic target in B-ALL and provide a rationale for the use of CK2 inhibitors in the treatment of high-risk B-ALL., (© 2016 by The American Society for Biochemistry and Molecular Biology, Inc.)

The KDM5/JARID1 family of Fe(II)- and α-ketoglutarate-dependent demethylases remove methyl groups from tri- and dimethylated lysine 4 of histone H3. Accumulating evidence from primary tumors and model systems supports a role for KDM5A (JARID1A/RBP2) and KDM5B (JARID1B/PLU1) as oncogenic drivers. The KDM5 family is unique among the Jumonji domain-containing histone demethylases in that there is an atypical insertion of a DNA-binding ARID domain and a histone-binding PHD domain into the Jumonji domain, which separates the catalytic domain into two fragments (JmjN and JmjC). Here we demonstrate that internal deletion of the ARID and PHD1 domains has a negligible effect on in vitro enzymatic kinetics of the KDM5 family of enzymes. We present a crystal structure of the linked JmjN-JmjC domain from KDM5A, which reveals that the linked domain fully reconstitutes the cofactor (metal ion and α-ketoglutarate) binding characteristics of other structurally characterized Jumonji domain demethylases. Docking studies with GSK-J1, a selective inhibitor of the KDM6/KDM5 subfamilies, identify critical residues for binding of the inhibitor to the reconstituted KDM5 Jumonji domain. Further, we found that GSK-J1 inhibited the demethylase activity of KDM5C with 8.5-fold increased potency compared with that of KDM5B at 1 mm α-ketoglutarate. In contrast, JIB-04 (a pan-inhibitor of the Jumonji demethylase superfamily) had the opposite effect and was ~8-fold more potent against KDM5B than against KDM5C. Interestingly, the relative selectivity of JIB-04 toward KDM5B over KDM5C in vitro translates to a ~10-50-fold greater growth-inhibitory activity against breast cancer cell lines. These data define the minimal requirements for enzymatic activity of the KDM5 family to be the linked JmjN-JmjC domain coupled with the immediate C-terminal helical zinc-binding domain and provide structural characterization of the linked JmjN-JmjC domain for the KDM5 family, which should prove useful in the design of KDM5 demethylase inhibitors with improved potency and selectivity., (© 2016 by The American Society for Biochemistry and Molecular Biology, Inc.)

MicroRNAs (miRNAs) are small non-coding RNAs that post-transcriptionally regulate gene expression. Alteration of miRNA levels is common in tumors and contributes to the pathogenesis of human malignancies. In the present study we examined the role played by miR-137 in breast tumorigenesis. We found miR-137 levels to be lower in breast cancer cells than in their non-tumorigenic counterparts and observed reduced proliferation and migration of breast cancer cells overexpressing miR-137. We further identified KDM5B, a histone demethylase known to be involved in breast cancer tumorigenesis, as a target of miR-137. As the involvement of histone demethylases in cancer is still poorly understood and as the role of miRNAs in controlling epigenetic mechanisms in cancer is emerging, we broadened our study to the whole KDM5 histone demethylase family to see if the genes coding for these epigenetic enzymes might be regulated by miRNAs in cancer cells. We discovered that KDM5C is overexpressed in breast cancer cells, providing evidence that miR-138 regulates its expression. We found miR-138 overexpression to affect breast cancer cell proliferation. Altogether, our findings suggest that miRNAs may regulate KDM5 histone demethylase levels in breast cancer and thereby control breast cancer cell proliferation and migration.

Transcriptional deregulation plays a major role in acute myeloid leukemia, and therefore identification of epigenetic modifying enzymes essential for the maintenance of oncogenic transcription programs holds the key to better understanding of the biology and designing effective therapeutic strategies for the disease. Here we provide experimental evidence for the functional involvement and therapeutic potential of targeting PRMT1, an H4R3 methyltransferase, in various MLL and non-MLL leukemias. PRMT1 is necessary but not sufficient for leukemic transformation, which requires co-recruitment of KDM4C, an H3K9 demethylase, by chimeric transcription factors to mediate epigenetic reprogramming. Pharmacological inhibition of KDM4C/PRMT1 suppresses transcription and transformation ability of MLL fusions and MOZ-TIF2, revealing a tractable aberrant epigenetic circuitry mediated by KDM4C and PRMT1 in acute leukemia., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background. While cancer/testis antigens (CTAs) are restricted in postnatal tissues to testes and germ line-derived cells, their role in cancer development and the clinical significance of their expression still remain to be better defined. Objective. The aim of this study was to investigate the level of CTA expression in colon samples from patients with colorectal cancer (CRC) in relation to patient clinical status. Methods. Forty-five patients with newly diagnosed colorectal cancer were included in the study. We selected a panel of 18 CTAs that were previously detected in CRC as well as some new gene candidates, and their expression was detected at the mRNA level by employing RQ-PCR. Additionally, we evaluated CTA expression in three colon cancer cell lines (CL-188, HTB-39, and HTB-37) after exposure to the DNA methylation-modifying drug 5-azacytidine. Results. We report that 6 out of 18 (33%) CTAs tested (MAGEA3, OIP5, TTK, PLU1, DKKL1, and FBXO39) were significantly (p < 0.05) overexpressed in tumor tissue compared with healthy colon samples isolated from the same patients. Conclusions. Moreover, we found that MAGEA3, PLU-1, and DKKL expression positively correlated with disease progression, evaluated according to the Dukes staging system. Finally, 5-azacytidine exposure significantly upregulated expression of CTAs on CRC cells, which indicates that this demethylation agent could be employed therapeutically to enhance the immune response against tumor cells.

Purpose: Oral squamous cell carcinoma (OSCC) is a major cause of human mortality globally and radiotherapy is one of the main treatment modalities, however its therapeutic effect is often limited by radioresistance. JARID1B is an epigenetic factor with reported oncogenic potential in various cancer types. We investigated the effect of JARID1B inhibition on migration and invasion of human OSCC cell lines, as well as on clinical patients' outcome., Materials and Methods: Wound healing, matrigel invasion, Sulforhodamine B, and spheroid formation assays were used to characterize the signaling pathways of shJARID1B in response to radiation treatment. We evaluated the prognostic relevance of Jarid1b expression in a cohort of 81 OSCC patients., Results: Human OSCC cell lines, including SAS, HSC3, Cal27, TW2.6 and SCC4 cells, were used. shJARID1B cells significantly inhibited migration and invasion ability compared to their vector or wild type counterparts. Silencing shJARID1B significantly inhibited oral cancer stem cell activity and potentiated the tumor-inhibitory activity of radiation therapy in OSCC. Radiotherapy coupled with shJARID1B knockdown reduced mRNA levels of NQO1, KEAP1, NRF2, FOXO1, FOXO3, KLF4, OCT4, CD133, and Nanog in malignant OSCC cells. OSCC spheroid formation ability was markedly reduced in the shJARID1B cells. JARID1B overexpression is a dependent prognostic factor in OSCC patients., Conclusions: Silencing shJARID1B inhibits migration and invasion of human OSCC, reduces cancer stem cell activities and potentiates tumor-inhibiting radiotherapeutic effects. JARID1B knockdown prior to radiotherapy is a potential effective therapeutic strategy for the treatment of OSCC., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Although three therapeutic modalities (surgical resection, chemotherapy, and radiotherapy) have been established, long-term survival for lung cancer patients is still generally poor. Until now, the mechanisms of lung cancer genesis remain elusive. The JARID1B is a histone demethylase that has been proposed as oncogene in several types of human cancer, but its clinical significance and functional role in human non-small cell lung cancer (NSCLC) remain unclear. In present study, we found that JARID1B was overexpressed in lung cancer cell lines and lung cancer tissues but not in normal lung tissues. The proliferation and invasive potential of lung cancer cells was significantly increased by ectopic expression of JARID1B. Contrarily, RNA interference targeting JARID1B in lung cancer cells significantly decreased the proliferation and invasive potential of cells. Moreover, we also found that the expression of p53 was modulated by JARID1B. Overexpressed JARID1B cell exhibited greatly decreased p53 expression, whereas silencing of JARID1B expression dramatically increased p53 expression at both the messenger RNA (mRNA) and protein levels. Inhibition of p53 by small interfering RNA (siRNA) reversed the shJARID1B-induced suppression of proliferation and invasion. Our results collectively suggested that JARID1B expressed in lung cancer played a role in lung cancer cells proliferation and invasion, which may be partly associated with the p53 expression.

The aims of this study were to investigate the expression of the H3K4 demethylase, jumonji AT-rich interactive domain 1B (JARID1B/KDM5B) and of p16 (multiple tumor suppressor gene MTS1) in breast cancer tissue and determine its clinicopathological significance. JARID1B/KDM5B and P16 protein expression in 176 resected breast cancer specimens and adjacent normal breast tissue was detected by the streptavidin-peroxidase (S-P) immunohistochemical method. The TNM staging grade was assigned according to the World Health Organization (2012) breast classification system. The positive staining rate of JARID1B/KDM5B and p16 protein in cancer tissue was 74.43 and 35.8%, respectively. JARID1B/KDM5B protein expression was positively associated with T grade, Bloom and Richardson (B&R) score and axillary lymph node metastasis (P < 0.05). p16 protein expression was negatively associated with T grade, B&R score, and axillary lymph node metastasis (P < 0.05). JARID1B/KDM5B and p16 protein expression in breast cancer and adjacent normal breast tissue were negatively correlated (r = -0.303, P < 0.001). The data demonstrated that protein expression of p16 and JARID1B/KDM5B is negatively correlated in invasive ductal carcinoma of the breast.

Neuroblastoma (NB) is a common neural crest-derived extracranial solid cancer in children. Among all childhood cancers, NB causes devastating loss of young lives as it accounts for 15% of childhood cancer mortality. Neuroblastoma, especially high-risk stage 4 NB with MYCN amplification has limited treatment options and associated with poor prognosis. This necessitates the need for novel effective therapeutic strategy. JARID1B, also known as KDM5B, is a histone lysine demethylase, identified as an oncogene in many cancer types. Clinical data obtained from freely-accessible databases show a negative correlation between JARID1B expression and survival rates. Here, we demonstrated for the first time the role of JARID1B in the enhancement of stem cell-like activities and drug resistance in NB cells. We showed that JARID1B may be overexpressed in either MYCN amplification (SK-N-BE(2)) or MYCN-non-amplified (SK-N-SH and SK-N-FI) cell lines. JARID1B expression was found enriched in tumor spheres of SK-N-BE(2) and SK-N-DZ. Moreover, SK-N-BE(2) spheroids were more resistant to chemotherapeutics as compared to parental cells. In addition, we demonstrated that JARID1B-silenced cells acquired a decreased propensity for tumor invasion and tumorsphere formation, but increased sensitivity to cisplatin treatment. Mechanistically, reduced JARID1B expression led to the downregulation of Notch/Jagged signaling. Collectively, we provided evidence that JARID1B via modulation of stemness-related signaling is a putative novel therapeutic target for treating malignant NB.

PLU-1/JARID1B (jumonji AT rich interactive domain 1B) is one of the testis cancer antigens and functions as a histone demethylase in the regulation of various human types of cancers. However, its functions in head and neck squamous cell carcinoma (HNSCC) are rarely reported. The aim of the present study was to examine PLU-1/JARID1B expression levels in HNSCCs and to investigate its role in cancer cell proliferation. In the present study, we found that PLU-1/JARID1B mRNA was upregulated in all tested HNSCC cell lines. Immunohistochemical staining showed that PLU-1/JARID1B protein expression was detected in 87.8% (87/99) of the HNSCC cases. A positive association was observed between high PLU-1/JARID1B expression and higher Ki-67 labeling in the HNSCC samples (Pearson r=0.6514, P=0.0003). Stable PLU-1/JARID1B knockdown by PLU-1-shRNAs in the HNSCC cell lines suppressed cell growth both in the in vitro and in vivo studies. Moreover, PLU-1/JARID1B knockdown resulted in G1 arrest and early apoptosis by suppressing Bcl-2 family members in the HNSCCs. These data indicate that PLU-1/JARID1B is overexpressed in HNSCCs and is associated with tumor proliferation and apoptosis. Therefore, PLU-1/JARID1B represents a candidate proliferation biomarker for HNSCC diagnosis and treatment.