Promising natural lysine specific demethylase 1 inhibitors for cancer treatment: advances and outlooks / 中国天然药物

Lysine specific demethylase 1 (LSD1), a transcriptional corepressor or coactivator that serves as a demethylase of histone 3 lysine 4 and 9, has become a potential therapeutic target for cancer therapy. LSD1 mediates many cellular signaling pathways and regulates cancer cell proliferation, invasion, migration, and differentiation. Recent research has focused on the exploration of its pharmacological inhibitors. Natural products are a major source of compounds with abundant scaffold diversity and structural complexity, which have made a major contribution to drug discovery, particularly anticancer agents. In this review, we briefly highlight recent advances in natural LSD1 inhibitors over the past decade. We present a comprehensive review on their discovery and identification process, natural plant sources, chemical structures, anticancer effects, and structure-activity relationships, and finally provide our perspective on the development of novel natural LSD1 inhibitors for cancer therapy.

ZNF750 facilitates carcinogenesis via promoting the expression of long non-coding RNA CYTOR and influences pharmacotherapy response in colon adenocarcinoma / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The epidermal cell differentiation regulator zinc finger protein 750 (ZNF750) is a transcription factor containing the Cys2His2 (C2H2) domain, the zinc finger structure of which is located at the N-terminal 25‍‍-‍46 amino acids of ZNF750. It can promote the expression of differentiation-related factors while inhibiting the expression of progenitor cell-related genes. ZNF750 is directly regulated by p63 (encoded by the TP63 gene, belonging to the TP53 superfamily). The Krüppel-like factor 4 (KLF4), repressor element-1 (RE-1)‍-silencing transcription factor (REST) corepressor 1 (RCOR1), lysine demethylase 1A (KDM1A), and C-terminal-binding protein 1/2 (CTBP1/2) chromatin regulators cooperate with ZNF750 to repress epidermal progenitor genes and activate the expression of epidermal terminal differentiation genes (Sen et al., 2012; Boxer et al., 2014). Besides, ZNF750 and the regulatory network composed of bone morphogenetic protein (BMP) signaling pathway, long non-coding RNAs (lncRNAs) (anti-differentiation non-coding RNA (ANCR) and tissue differentiation-inducing non-protein coding RNA (TINCR)), musculoaponeurotic fibrosarcoma oncogene (MAF)/MAF family B (MAFB), grainy head-like 3 (GRHL3), and positive regulatory domain zinc finger protein 1 (PRDM1) jointly promote epidermal cell differentiation (Sen et al., 2012).

Treatment and genetic analysis of a child with Kabuki syndrome type 2 and secondary pulmonary infection due to a de novo variant of KDM6A gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis of a child with recurrent infection, multiple malformation and dysmorphism.@*METHODS@#The child and his parents were subjected to trio whole exome sequencing.@*RESULTS@#The child had a complaint of fever and cough, with long and thin eye fissures and long eyelashes. Genetic testing revealed that the child has carried a non-triplet deletion of the KDM6A gene, which was unreported previously. The variant resulted in frameshift and premature termination of the translation. His parents were both of the wild type for the locus. After antibiotic and immunoglobulin treatment, the severe secondary pneumonia caused by immunodeficiency has improved.@*CONCLUSION@#With combined laboratory test, imaging examination and genetic testing, the child was ultimately diagnosed with Kabuki syndrome type 2. The characteristics of immunodeficiency of Kabuki syndrome may render conventional antibiotic treatment ineffective, which deserves clinical attention.

Pioneer of prostate cancer: past, present and the future of FOXA1

Prostate cancer is the most commonly diagnosed non-cutaneous cancers in North American men. While androgen deprivation has remained as the cornerstone of prostate cancer treatment, resistance ensues leading to lethal disease. Forkhead box A1 (FOXA1) encodes a pioneer factor that induces open chromatin conformation to allow the binding of other transcription factors. Through direct interactions with the Androgen Receptor (AR), FOXA1 helps to shape AR signaling that drives the growth and survival of normal prostate and prostate cancer cells. FOXA1 also possesses an AR-independent role of regulating epithelial-to-mesenchymal transition (EMT). In prostate cancer, mutations converge onto the coding sequence and cis-regulatory elements (CREs) of FOXA1, leading to functional alterations. In addition, FOXA1 activity in prostate cancer can be modulated post-translationally through various mechanisms such as LSD1-mediated protein demethylation. In this review, we describe the latest discoveries related to the function and regulation of FOXA1 in prostate cancer, pointing to their relevance to guide future clinical interventions.

Genomic and transcriptomic characterization of the human glioblastoma cell line AHOL1

Cancer cell lines are widely used as in vitro models of tumorigenesis, facilitating fundamental discoveries in cancer biology and translational medicine. Currently, there are few options for glioblastoma (GBM) treatment and limited in vitro models with accurate genomic and transcriptomic characterization. Here, a detailed characterization of a new GBM cell line, namely AHOL1, was conducted in order to fully characterize its molecular composition based on its karyotype, copy number alteration (CNA), and transcriptome profiling, followed by the validation of key elements associated with GBM tumorigenesis. Large numbers of CNAs and differentially expressed genes (DEGs) were identified. CNAs were distributed throughout the genome, including gains at Xq11.1-q28, Xp22.33-p11.1, Xq21.1-q21.33, 4p15.1-p14, 8q23.2-q23.3 and losses at Yq11.21-q12, Yp11.31-p11.2, and 15q11.1-q11.2 positions. Nine druggable genes were identified, including HCRTR2, ETV1, PTPRD, PRKX, STS, RPS6KA6, ZFY, USP9Y, and KDM5D. By integrating DEGs and CNAs, we identified 57 overlapping genes enriched in fourteen pathways. Altered expression of several cancer-related candidates found in the DEGs-CNA dataset was confirmed by RT-qPCR. Taken together, this first comprehensive genomic and transcriptomic landscape of AHOL1 provides unique resources for further studies and identifies several druggable targets that may be useful for therapeutics and biologic and molecular investigation of GBM.

Inibidores de Desmetilase Lisina-Específica 1 (LSD1) como candidatos a agentes antineoplásicos / Lysine-Specif Demethylase 1 (LSD1) inhibitors as candidates for antineoplastic agents

O câncer é uma das principais causas de morte no mundo sendo, atualmente, a segunda principal causa de morte, perdendo apenas para as doenças cardiovasculares, tornando-se um grande desafio para as autoridades de saúde pública. No Brasil são estimados 625000 novos casos desta enfermidade para o triênio de 2020-2022. Nesse cenário, vários alvos epigenéticos são considerados alternativas no desenvolvimento de inibidores para a terapia do câncer devido serem identificados e relacionados com a carcinogênese, incluindo modificações no perfil de metilação do DNA e modificações de histonas como a metilação, acetilação e fosforilação. Dentre estas modificações, a metilação de histonas é regulada reversivelmente por histonas metiltransferases e desmetilases. A enzima desmetilase lisina-específica 1 (LSD1) foi a primeira histona desmetilase caracterizada e catalisa a remoção de grupos metila das lisinas 4 e 9 da histona H3 (H3K4 e H3K9), utilizando o FAD como cofator. Superexpressa em vários tumores de alto risco e tendo seus níveis correlacionados com a reincidência do tumor durante o tratamento, a LSD1 apresenta papel fundamental na tumorgênese. Portanto, tem sido considerado um alvo biológico promissor no desenvolvimento de novos fármacos para terapêutica contra o câncer. Sendo assim, neste trabalho, a partir de dados de triagem virtual baseado neste alvo biológico, selecionou-se um hit, o qual foi utilizado como protótipo para o planejamento de análogos visando melhorar as características farmacológicas, pois possuem grupos químicos passíveis das mesmas interações com o alvo. Foram sintetizadas 16 moléculas, sendo 7 compostos finais inéditos derivados carboxamídicos e 9 derivados sulfonamídicos. Todos os compostos foram caracterizados por RMN (1H e 13C), espectrometria de massas de alta resolução, espectroscopia de infravermelho, ponto de fusão, polarímetro e a pureza dos compostos foi avaliada por CLAE. Os compostos finais foram submetidos ao ensaio enzimático frente à LSD1, acoplado a Enzima Horseradish Peroxidase (EHP), mostrando que apenas o composto 4g apresentou atividade inibitória de 64% e 57% em 50 µM e 500 µM respectivamente. No ensaio de viabilidade celular na linhagem HEL (linhagem leucêmica) os 16 compostos (4a- 4g, 5a-5d e 6a-6d) apresentaram-se ativos com valores de CI50 na faixa de 5,3 µM a 20,25 µM. Os compostos mais potentes foram os 4e (CI50 = 6,9 µM), 5d (CI50 =5,30 µM) e 6ª (CI50 =6,61 µM), evidenciando que os compostos possuem elevada potência, tornando-se moléculas promissoras em linhagens leucêmicas. Os estudos de ancoramento molecular com a LSD1 sugeriram que a mudança de orientação do composto 4g, permitiu que o grupo benzila da porção benzilamida faça interação com os resíduos PHE560 e TYR807 no bolso hidrofóbico, o que possivelmente acarretou um bloqueio na entrada da cavidade, permitindo a inibição pelo composto

Cancer is one of the leading causes of death in the world and is currently the second leading cause of death, second only to cardiovascular disease, making it a major challenge for public health authorities. In Brazil, approximately, 625000 new cases of this disease are estimated for the 2020-2022 period. In this scenario, several epigentic targets are considered alternatives in the development of inhibitors in cancer therapy, since they are identified and related to carcinogenesis, including changes in the DNA methylation profile and changes in histones such as methylation, acetylation and phosphorylation. Among these modifications, histone methylation is reversibly regulated by histones methyltransferases and demethylases. Lysine-specific demethylase1 (LSD1) was the first histone demethylase characterized and catalyzes the removal of methyl groups from lysines 4 and 9 of histone H3 (H3K4 and H3K9), using FAD as a cofactor. LSD1 has been found to be overexpressed in several high-risk tumors and these levels are correlated with tumor recurrence during treatment. Therefore, it has been considered a promising biological target in the development of new drugs with therapeutic potential against cancer. Thus, in this work, the virtual screening technique based on the biological target was used to discover LSD1 interactions, and then based on the hit found, we propose to synthesize compounds that have chemical groups susceptible to such interactions, seeking to evaluate the enzymatic activity in LSD1 enzyme. Were synthesized 16 molecules, 7 of which are unpublished final compound derived from carboxamides and 9 sulfonamide derivatives. All compounds were characterized by NMR (1H and 13C), high resolution mass spectrometry, infrared spectroscopy, melting point, polarimeter and the purity of the compounds was assessed by CLAE. The final compounds were subjected to enzymatic assays Against LSD1, coupled with enzime Horseradish Peroxidase (HRP), showing that only the 4g compound showed 64% and 57% inhibitory activity in 50 µM and 500 µM respectively. In the cell viability assay in the HEL line (Leukemic line) the 16 compounds (4a-4g, 5a-5d and 6a-6d) were active with IC 50 values in the range of 5.3 µM to 20.25 µM. The most potent compounds were 4e (CI50 = 6.9 µM), 5d (CI50 = 5.30 µM) and 6a (CI50 = 6.61 µM), showing that the compounds have high potency, becoming promising molecules in leukemic lines. Docking studies with LSD1 suggested, that the change in orientation of the 4g compound allows the benzyl group of the benzylamide portion to interact with the PHE560 and TYR807 residues in the hydrophobic pocket, which possibly cause a block in the entrance of the cavity, allowing the inhibition by the compound. Thus, the results obtained indicate that the class of compounds described is likely to continue to be investigated, both in the search for new LSD1 inhibitory hits based on the structure of the 4g compound, how to deepen the studies with 16 compounds of the present work in the performance of more specific tests in leukemic cells, in order to unravel the mechanism of action and possible targets

Prenatal diagnosis of a fetus with cleft lip and palate by using chromosomal microarray analysis / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a fetus with cleft lip and palate.@*METHODS@#Copy number variations (CNVs) in the fetus and his parents were detected with chromosomal microarray analysis (CMA).@*RESULTS@#As revealed by the CMA assay, the fetus has carried a 228 kb deletion in Xp11.22 region and a 721 kb duplication in 9p21.1. Both CNVs were inherited from the parents. The CNV in Xp11.22 was predicted to be pathogenic by involving the PHF8 gene, whilst the CNV in 9p21.1 was predicted to be benign.@*CONCLUSION@#Deletion of the Xp11.22 region probably underlies the cleft lip and palate in this fetus.

Clinical features and gene variant of a pedigree affected with X-linked recessive mental retardation Claes-Jensen type / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a pedigree affected with X-linked recessive mental retardation Claes-Jensen type.@*METHODS@#Genomic DNA was extracted from peripheral blood samples of the patient, his parents (phenotypically normal) and two elder brothers with similar clinical manifestations. Whole exome sequencing was carried out for the proband, and the result was verified by Sanger sequencing.@*RESULTS@#The proband was found to harbor a hemizygous c.1565C>T missense variant in exon 11 of the KDM5C gene. The transition has resulted in replacement of serine by phenylalanine at position 522 (p.Ser522Phe). Sanger sequencing showed that the patient's two elder brothers and mother carried the same variant, which was predicted to be probably damaging by SIFT, PolyPhen2 and Mutation_Taster. The three affected brothers presented with similar clinical phenotypes characterized by mental retardation, speech delay, behavioral problem, self-limited epilepsy responsible to medication, short stature and microcephaly. The mother only had mild cognitive impairment and learning disability. The same variant was not found in their father and was unreported previously.@*CONCLUSION@#The c.1565C>T (p.Ser522Phe) of the KDM5C gene probably underlay the X-linked recessive mental retardation Claes-Jensen type in this pedigree.

Knocking down LSD1 inhibits the stemness features of colorectal cancer stem cells

As a top leading cause of cancer death in many countries, colorectal cancer (CRC) has drawn increasing attention to the study of the pathological mechanism. According to the "cancer stem cell hypothesis", malignancies originate from a small fraction of cancer cells that show self-renewal properties to initiate and sustain tumor growth and tumor metastasis. Therefore, these cancer stem cells (CSC) probably play important roles in tumor recurrence, metastasis, and drug resistance. Previous research reported that lysine-specific histone demethylase 1 (LSD1) maintains cancer stemness through up-regulating stemness markers SOX2 and OCT4. CD133 is believed to be the most robust surface marker for CRC stem cells, however the regulatory effect of LSD1 on stemness of CD133+ CRC has never been reported. In this study, our objectives included: 1) to isolate pure CD133+ and CD133− cells from SW620 cell line; 2) to investigate the effect of LSD1 on the characteristics of CD133+ stem cancer cells by knocking down the target gene. Results suggested that the SW620 cell line had both CD133+ and CD133− subsets. The CD133+ subset exhibited more CSC-like characteristics compared with the CD133− subset with higher viability, colony formation rate, migration and invasion rate, resistance to anti-cancer drugs, and apoptosis in vitro. The CD133+ also induced faster tumor formation and larger tumors in vivo. In the LSD1-knockdown CD133+ cells, the CSC-like characteristics had been all weakened. We conclude that LSD1 was important for CSCs to maintain their "stemness" features, which could be a potential therapeutic target of CRC.

Research Advances in Lysine-specific Demethylase 6A and Its Application in Treating Leukemia / 中国医学科学院学报

Leukemia is a disease featured by the malignant proliferation of hematopoietic stem cells or progenitor cells in the blood system.While chemotherapy remains its mainstream treatment,disease relapse and drug resistance are still challenging problems.As one of the epigenetic mechanisms,histone methylation is involved in cell proliferation,differentiation,and apoptosis by regulating gene transcription.Recent studies have found that the histone demethylase lysine-specific demethylase 6A(KDM6A),also known as ubiquitously transcribed tetratricopeptide repeat on chromosome X(UTX),is closely related to the occurrence of a variety of tumors,especially leukemia.KDM6A activates gene expression by demethylating H3K27me3 to H3K27me2 or H3K27me1.Besides,KDM6A can regulate the activation of the target gene transcription through its non-demethylase functions.It can serve as the subunit of complex of proteins associated with Set1,thus getting involved in the regulation of H3K4me1.It can be combined with yeast mating type conversion/sucrose unfermented complex family to promote the formation of an open chromatin conformation.Finally,it can promote the production of H3K27ac.This article reviews the recent studies on the structure and biological activity of histone demethylase KDM6A(UTX)and its role in treating leukemia,thus providing a new research direction for targeted treatment of leukemia.

The deubiquitinase USP38 affects cellular functions through interacting with LSD1

BACKGROUND: Deubiquitination is a posttranslational protein modification prevalent in mammalian cells. Deubiquitinases regulate the functions of the target protein by removing its ubiquitin chain. In this study, the effects of the deubiquitinase USP38's functions on the LSD1 protein and on cell physiology were investigated. MATERIALS AND METHODS: Western blotting, real-time quantitative PCR, immunoprecipitation, denaturing immunoprecipitation and luciferase reporter assays were used to analyze the protein stability, protein interactions and changes in the ubiquitin chain. Cell proliferation assays, colony formation assays, drug treatments and western blotting were used to explore the functions of USP38 in cells. RESULTS: The deubiquitinase USP38 stabilizes protein LSD1 in cells by binding LSD1 and cleaving its ubiquitin chain to prevent the degradation of LSD1 by the intracellular proteasome. USP38 enhances the ability of LSD1 to activate signaling pathways and hence promotes cellular abilities of proliferation and colony formation through interacting with LSD1. Furthermore, USP38 enhances the drug tolerance of human colon cancer cells. CONCLUSIONS: USP38 is an LSD1-specific deubiquitinase that affects cellular physiology through interacting with LSD1.

Histone lysine demethylases in mammalian embryonic development

Post-translational modifications, such as methylation, acetylation and phosphorylation, of histone proteins play important roles in regulating dynamic chromatin structure. Histone demethylation has become one of the most active research areas of epigenetics in the past decade. To date, with the exception of histone H3 lysine 79 methylation, the demethylases for all major lysine methylation sites have been discovered. These enzymes have been shown to be involved in various biological processes, with embryonic development being an exciting emerging area. This review will primarily discuss the involvement of these demethylases in the regulation of mammalian embryonic development, including their roles in embryonic stem cell pluripotency, primordial germ cell (PGC) formation and maternal-to-zygotic transition.

The pilot study on the expression of PHF8, H3K9me2, BDNF and LTP in the hippocampus of rats exposed to aluminum / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>In this research, we have observed changes of PHF8、H3K9me2、BDNF, and their regulatory roles in changing the amplitude value of LTP in hippocampus due to aluminum exposure so that we can discuss the impact on the learning and memory that caused by chronic aluminum exposure.</p><p><b>METHODS</b>Forty healthy SPF grade SD male rats were randomly divided into four groups by weight, including control group and low, medium, high dose aluminum exposed group, each group had 10 rats. The exposed rats drank water containing different doses of aluminum chloride (AlCl3) (2、12、72 mg/kg Al(3+)) for 90 d. We measured LTP in hippocampus by electrophysiological grapier and detected the expression of PHF8、H3K9me2、BDNF by western-blot.</p><p><b>RESULTS</b>Electrophysiological measurements shows that compared with that of control group, the average of fEPSPs was decreased at different time points in all exposed groups (P<0.01) . The results of western-bolt test demonstrated that the expression of PHF8 in the exposed groups were significantly lower than those of control group (P<0.01) . And the expression the of H3K9me2 of medium and high dose groups were significantly higher than control group (P<0.05) . While the expression of BDNF of medium and high dose groups were decreased compared with the control group (P<0.05) .</p><p><b>CONCLUSION</b>Chronic aluminum exposure can reduce the LTP via the route of PHF8-H3K9me2-BDNF in the hippocampus of rats, which then may impair the ability of learning and memory.</p>

RBP2 induces stem-like cancer cells by promoting EMT and is a prognostic marker for renal cell carcinoma

Renal cell carcinoma (RCC), one of the most common kidney cancers, has a poor prognosis. Epithelial to mesenchymal transition (EMT) is a hallmark of carcinoma invasion and metastasis. Several studies have examined the molecular regulation of EMT, but the relationship between histone demethylases and EMT is little understood. In this study, we investigated the role of retinoblastoma-binding protein-2 (RBP2), a histone demethylase that is highly expressed in RCC and is positively correlated with poor RCC prognosis in the regulation of EMT. We found that ectopic overexpression of RBP2 can induce cancer stem cell-like (CSC) phenotypes through EMT in RCC cells by converting them to a more mesenchymal phenotype. This results in increased resistance to apoptosis, which leads to enhanced tumor growth in xenograft models. Together, our data show that RBP2 is an epigenetic regulator that has an important role in the initiation of CSC phenotypes through EMT, leading to tumor progression. RBP2 is also a novel biomolecule for RCC diagnosis, and prognosis and may be a therapeutic target.

Antiproliferative effect of silencing LSD1 gene on Jurkat cell line and its mechanism / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of silencing LSD1 gene by RNA interference on the proliferation, apoptosis on human lymphocytic leukemia Jurkat cell line and its mechanism.</p><p><b>METHODS</b>The hairpin- like oligonucleotide sequences targeting LSD1 gene was transfected into Jurkat cells by lipofectamine(TM) 2000. The LSD1 mRNA and protein were detected by RQ- PCR and Western blot. Cell growth was determined by MTT. Cell apoptosis was analyzed by flow cytometry. The expression of Bcl-2, Bax, procaspase- 3, and histone H3K4me, H3K4me2, H3K4me3, Act- H3, H3K9me were detected by Western blot.</p><p><b>RESULTS</b>LSD1 mRNA was markedly suppressed by the shRNA targeting LSD1. LSD1 shRNA suppressed the proliferation and induced cells apoptosis of Jurkat cells. The cell apoptotic rate was (41.34±3.58)%, (3.45±1.54)%, (1.76±0.52)% in LSD1 shRNA, Neg-shRNA and Blank respectively, the difference among them was statistically significant (P<0.05). LSD1 shRNA down- regulated the expressions of Bcl- 2 and procaspase- 3, and up- regulated the expression of Bax. The methylation of H3K4me1, me2 and acetylation of Act- H3 improved without change of the methylation of H3K4me3.</p><p><b>CONCLUSIONS</b>Deplete of LSD1 gene maybe through modifying the methylation of histone H3K4 to promote the cell apoptosis and inhibit cell growth in Jurkat cell line.</p>

Histone methyltransferases and demethylases: regulators in balancing osteogenic and adipogenic differentiation of mesenchymal stem cells / 国际口腔科学杂志·英文版

Mesenchymal stem cells (MSCs) are characterized by their self-renewing capacity and differentiation potential into multiple tissues. Thus, management of the differentiation capacities of MSCs is important for MSC-based regenerative medicine, such as craniofacial bone regeneration, and in new treatments for metabolic bone diseases, such as osteoporosis. In recent years, histone modification has been a growing topic in the field of MSC lineage specification, in which the Su(var)3-9, enhancer-of-zeste, trithorax (SET) domain-containing family and the Jumonji C (JmjC) domain-containing family represent the major histone lysine methyltransferases (KMTs) and histone lysine demethylases (KDMs), respectively. In this review, we summarize the current understanding of the epigenetic mechanisms by which SET domain-containing KMTs and JmjC domain-containing KDMs balance the osteogenic and adipogenic differentiation of MSCs.

Epigenetic Role of Histone 3 Lysine Methyltransferase and Demethylase in Regulating Apoptosis Predicting the Recurrence of Atypical Meningioma

Alteration of apoptosis is related with progression and recurrence of atypical meningiomas (AMs). However, no comprehensive study has been conducted regarding histone modification regulating apoptosis in AMs. This study aimed to determine the prognostic values of certain apoptosis-associated factors, and examine the role of histone modification on apoptosis in AMs. The medical records of 67 patients with AMs, as diagnosed during recent 13 yr, were reviewed retrospectively. Immunohistochemical staining was performed on archived paraffin-embedded tissues for pro-apoptotic factors (CASP3, IGFBP, TRAIL-R1, BAX, and XAF1), anti-apoptotic factors (survivin, ERK, RAF1, MDM2, and BCL2), and the histone modifying enzymes (MLL2, RIZ, EZH1, NSD2, KDM5c, JMJD2a, UTX, and JMJD5). Twenty-six (38.8%) patients recurred during the follow-up period (mean duration 47.7 months). In terms of time-to-recurrence (TTR), overexpression of CASP3, TRAIL-R1, and BAX had a longer TTR than low expression, and overexpression of survivin, MDM2, and BCL2 had a shorter TTR than low expression (P<0.05). Additionally, overexpression of MLL2, UTX, and JMJ5 had shorter TTRs than low expression, and overexpression of KDM5c had a longer TTR than low expression. However, in the multi-variate analysis of predicting factors for recurrence, low expression of CASP3 (P<0.001), and BAX (P<0.001), and overexpression of survivin (P=0.007), and MDM2 (P=0.037) were associated with recurrence independently, but any enzymes modifying histone were not associated with recurrence. Conclusively, this study suggests certain apoptosis-associated factors should be associated with recurrence of AMs, which may be regulated epigenetically by histone modifying enzymes.

Histone demethylase retinoblastoma binding protein 2 regulates the expression of -smooth muscle actin and vimentin in cirrhotic livers

Liver cirrhosis is one of the most common diseases of Chinese patients. Herein, we report the high expression of a newly identified histone 3 lysine 4 demethylase, retinoblastoma binding protein 2 (RBP2), and its role in liver cirrhosis in humans. The siRNA knockdown of RBP2 expression in hepatic stellate cells (HSCs) reduced levels of α-smooth muscle actin (α-SMA) and vimentin and decreased the proliferation of HSCs; and overexpression of RBP2 increased α-SMA and vimentin levels. Treatment with transforming growth factor β (TGF-β) upregulated the expression of RBP2, α-SMA, and vimentin, and the siRNA knockdown of RBP2 expression attenuated TGF-β-mediated upregulation of α-SMA and vimentin expression and HSC proliferation. Furthermore, RBP2 was highly expressed in cirrhotic rat livers. Therefore, RBP2 may participate in the pathogenesis of liver cirrhosis by regulating the expression of α-SMA and vimentin. RBP2 may be a useful marker for the diagnosis and treatment of liver cirrhosis.

Sonic hedgehog signaling enhanced the expression of histone demethylase, lysine-specific demethylase 8 in the head and neck squamous cell carcinoma cell line SCC-6 / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To determine whether the sonic hedgehog (Shh) signaling could regulate the expression of histone demethylases in the head and neck squamous cell carcinoma(SCC).</p><p><b>METHODS</b>Human recombinant SHH-N protein or over-expression of the mutant 2 smoothened (M2-SMO) was applied to activate the Shh signaling in tongue squamous cell carcinoma cell line-SCC-6 in this study. Cyclopamine was used to block the Shh signaling in SCC-6. The real-time reverse transcription (RT)-PCR was used to detect the expression of histone demethylases at the mRNA level.</p><p><b>RESULTS</b>The data showed that activation of the Shh signaling up-regulated the expression of histone demethylase, lysine-specific demethylase 8 (KDM-8) at the mRNA level by human recombinant SHH-N protein (1.841 ∼ 3.591 fold compare with untreated group; P < 0.01), over-expression of the M2-SMO also increased the expression of KDM-8 (1.358 ∼ 3.013 fold compared with empty vector group; P < 0.05), and after the Shh signaling was blocked by Cyclopamine, the expression of KDM-8 was down regulated (decreased 25.6% ∼ 66.6% compared with control cells, P < 0.05).</p><p><b>CONCLUSIONS</b>Histone demethylase KDM-8 was downstream target gene of Shh signaling in head and neck squamous cell carcinoma cell line SCC-6, and its expression was positively regulated by the Shh signaling.</p>

Lysine-specific demethylase 1 represses THP-1 monocyte-to-macrophage differentiation / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the role of lysine-specific demethylase 1 (LSD1) in the process of THP-1 monocyte-to-macrophage differentiation.</p><p><b>METHODS</b>Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting were performed to analyze the expression of LSD1 and interleukin-6 (IL-6) in THP-1 monocytes and THP-1-derived macrophages. Chromatin immunoprecipitation (ChIP) assay was applied to detect the occupancy of LSD1 and H3K4 methylation at IL-6 promoter during THP-1 monocyte-to-macrophage differentiation. IL-6 mRNA level and H3K4 methylation at IL-6 promoter were analyzed using qRT-PCR and ChIP assay in LSD1-knockdown THP-1 cells treated with 12-O-tetradecanoylphorbol-13-acetate (TPA) for 0, 4, 8, 12, and 24 hours. Fluorescence activated flow cytometry was performed to reveal the percentage of macrophages differentiated from THP-1 monocytes.</p><p><b>RESULTS</b>The expression of LSD1 reduced during THP-1 monocyte-to-macrophage differentiation (P<0.01). LSD1 occupancy decreased and H3K4 methylation increased at IL-6 promoter during the differentiation. With knockdown of LSD1, H3K4 methylation at IL-6 promoter was found increased after TPA treatment at different times points (all P<0.05, except 24 hours). The percentage of macrophages increased significantly in the THP-1 cells with LSD1 knockdown (P<0.05).</p><p><b>CONCLUSIONS</b>LSD1 is repressed during the monocyte-to-macrophage differentiation of THP-1 cells. Suppression of LSD1-mediated H3K4 demethylation may be required for THP-1 monocyte-to-macrophage differentiation.</p>