MBD1

Gene Summary

Gene:MBD1; methyl-CpG binding domain protein 1
Aliases: RFT, PCM1, CXXC3
Location:18q21.1
Summary:The protein encoded by this gene is a member of a family of nuclear proteins related by the presence of a methyl-CpG binding domain (MBD). These proteins are capable of binding specifically to methylated DNA, and some members can also repress transcription from methylated gene promoters. This protein contains multiple domains: MBD at the N-terminus that functions both in binding to methylated DNA and in protein interactions; several CXXC-type zinc finger domains that mediate binding to non-methylated CpG dinucleotides; transcriptional repression domain (TRD) at the C-terminus that is involved in transcription repression and in protein interactions. Numerous alternatively spliced transcript variants encoding different isoforms have been noted for this gene.[provided by RefSeq, Feb 2011]
Databases:VEGA, OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:methyl-CpG-binding domain protein 1
Source:NCBIAccessed: 11 March, 2017

Ontology:

What does this gene/protein do?
Show (12)

Cancer Overview

Research Indicators

Publications Per Year (1992-2017)
Graph generated 11 March 2017 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

  • Transcription Factors
  • Chromatin
  • DNA Methylation
  • Drug Resistance
  • Messenger RNA
  • Histones
  • Gene Silencing
  • p300-CBP Transcription Factors
  • Neoplasm Proteins
  • Histone Deacetylase Inhibitors
  • Colonic Neoplasms
  • HeLa Cells
  • Protein Interaction Domains and Motifs
  • Epigenetics
  • Protein Binding
  • Chromatin Immunoprecipitation
  • Receptors, Progesterone
  • RNA Interference
  • Down-Regulation
  • Promoter Regions
  • Prostate Cancer
  • siRNA
  • Neoplastic Cell Transformation
  • Non-Small Cell Lung Cancer
  • Breast Cancer
  • Cancer Gene Expression Regulation
  • Hydroxamic Acids
  • Vinblastine
  • Azacitidine
  • Transcription
  • Pancreatic Cancer
  • CpG Islands
  • Methyl-CpG-Binding Protein 2
  • Repressor Proteins
  • Urokinase-Type Plasminogen Activator
  • Transfection
  • Lung Cancer
  • DNA (Cytosine-5-)-Methyltransferase
  • Colorectal Cancer
  • DNA-Binding Proteins
  • Chromosome 18
  • Binding Sites
Tag cloud generated 11 March, 2017 using data from PubMed, MeSH and CancerIndex

Specific Cancers (6)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: MBD1 (cancer-related)

Zhang B, Xu J, Li C, et al.
MBD1 is an Epigenetic Regulator of KEAP1 in Pancreatic Cancer.
Curr Mol Med. 2016; 16(4):404-11 [PubMed] Related Publications
BACKGROUND: MBD1 (Methyl-CpG Binding Domain Protein 1) is highly expressed in pancreatic cancer. Nrf2 (NF-E2 p45-related factor 2) and the 'antioxidant response element' (ARE)-driven genes that NRF2 controls are frequently upregulated in pancreatic cancer and correlate with poor survival. Keap1 (Kelch-like ECH-associated protein 1) is a dominant negative regulator of NRF2 and is reported to be epigenetically regulated by promoter methylation. However, the role of MBD1 with antioxidant response and its association with KEAP1 has never been reported before and remains unclear.
OBJECTIVE: We investigated the role of MBD1 in antioxidant response and its regulatory function in KEAP1 transcription in pancreatic cancer cells.
METHOD: MBD1 was silenced to examine its role in antioxidant response. To explore the underlying mechanism, transcriptional and protein levels of KEAP1 was examined. The correlation between MBD1 and KEAP1 was confirmed in pancreatic cancer tissue samples by using immunohistochemistry (IHC). Dualluciferase reporter assay and Chromatin immunoprecipitation (ChIP) were used to elucidate he mechanism of MBD1 in KEAP1 transcriptional control. Moreover, co-immunoprecipitation (CoIP) assay was performed to uncover the regulatory role of MBD1 in KEAP1 transcription through its association with c-myc.
RESULTS: MBD1 silencing decreased antioxidant response and the related ARE target genes through epigenetic regulation of KEAP1. MBD1 negatively correlated with KEAP1 in pancreatic cancer tissue samples. Moreover, c-myc was a MBD1 interaction partner in KEAP1 epigenetic regulation.
CONCLUSION: MBD1 can induce antioxidant response in pancreatic cancer through down-regulation of KEAP1. c-myc plays a key role in MBD1 mediated epigenetic silencing of KEAP1.

Devailly G, Grandin M, Perriaud L, et al.
Dynamics of MBD2 deposition across methylated DNA regions during malignant transformation of human mammary epithelial cells.
Nucleic Acids Res. 2015; 43(12):5838-54 [PubMed] Free Access to Full Article Related Publications
DNA methylation is thought to induce transcriptional silencing through the combination of two mechanisms: the repulsion of transcriptional activators unable to bind their target sites when methylated, and the recruitment of transcriptional repressors with specific affinity for methylated DNA. The Methyl CpG Binding Domain proteins MeCP2, MBD1 and MBD2 belong to the latter category. Here, we present MBD2 ChIPseq data obtained from the endogenous MBD2 in an isogenic cellular model of oncogenic transformation of human mammary cells. In immortalized (HMEC-hTERT) or transformed (HMLER) cells, MBD2 was found in a large proportion of methylated regions and associated with transcriptional silencing. A redistribution of MBD2 on methylated DNA occurred during oncogenic transformation, frequently independently of local DNA methylation changes. Genes downregulated during HMEC-hTERT transformation preferentially gained MBD2 on their promoter. Furthermore, depletion of MBD2 induced an upregulation of MBD2-bound genes methylated at their promoter regions, in HMLER cells. Among the 3,160 genes downregulated in transformed cells, 380 genes were methylated at their promoter regions in both cell lines, specifically associated by MBD2 in HMLER cells, and upregulated upon MBD2 depletion in HMLER. The transcriptional MBD2-dependent downregulation occurring during oncogenic transformation was also observed in two additional models of mammary cell transformation. Thus, the dynamics of MBD2 deposition across methylated DNA regions was associated with the oncogenic transformation of human mammary cells.

Du Q, Luu PL, Stirzaker C, Clark SJ
Methyl-CpG-binding domain proteins: readers of the epigenome.
Epigenomics. 2015; 7(6):1051-73 [PubMed] Related Publications
How DNA methylation is interpreted and influences genome regulation remains largely unknown. Proteins of the methyl-CpG-binding domain (MBD) family are primary candidates for the readout of DNA methylation as they recruit chromatin remodelers, histone deacetylases and methylases to methylated DNA associated with gene repression. MBD protein binding requires both functional MBD domains and methyl-CpGs; however, some MBD proteins also bind unmethylated DNA and active regulatory regions via alternative regulatory domains or interaction with the nucleosome remodeling deacetylase (NuRD/Mi-2) complex members. Mutations within MBD domains occur in many diseases, including neurological disorders and cancers, leading to loss of MBD binding specificity to methylated sites and gene deregulation. Here, we summarize the current state of knowledge about MBD proteins and their role as readers of the epigenome.

Choi YY, Lee SY, Lee WK, et al.
RACK1 is a candidate gene associated with the prognosis of patients with early stage non-small cell lung cancer.
Oncotarget. 2015; 6(6):4451-66 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: This study was conducted to identify genetic polymorphisms associated with the prognosis of patients with early stage NSCLC.
MATERIALS AND METHODS: We genotyped 1,969 potentially functional single nucleotide polymorphisms (SNPs) of 1,151 genes involved in carcinogenesis in 166 NSCLC patients who underwent curative surgery, using the Affymetrix custom-made GeneChip. A replication study was performed in an independent cohort of 626 patients.
RESULTS: Fifty six SNPs which were associated with both overall survival (OS) and disease-free survival (DFS) with log-rank P values < 0.05 in discovery set were selected for validation. Among those, five SNPs (RACK1 rs1279736C>A and rs3756585T>G, C3 rs2287845T>C, PCAF rs17006625A>G, and PCM1 rs17691523C>G) were found to be significantly associated with survival in the same direction as the discovery set. In combined analysis, the rs1279736C>A and rs3756585T>G were most significantly associated with OS and DFS in multivariate analysis (P for OS = 4 × 10⁻⁵ and 7 × 10⁻⁵, respectively; and P for DFS = 0.003, both; under codominant model). In vitro promoter assay and electrophoretic mobility shift assay revealed that the rs3756585 T-to-G change increased promoter activity and transcription factor binding of RACK1.
CONCLUSIONS: We identified five SNPs, especially RACK1 rs3756585T>G, as markers for prognosis of patients with surgically resected NSCLC.

Sandgren J, Holm S, Marino AM, et al.
Whole Exome- and mRNA-Sequencing of an AT/RT Case Reveals Few Somatic Mutations and Several Deregulated Signalling Pathways in the Context of SMARCB1 Deficiency.
Biomed Res Int. 2015; 2015:862039 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: AT/RTs are rare aggressive brain tumours, mainly affecting young children. Most cases present with genetic inactivation of SMARCB1, a core member of the SWI/SNF chromatin-remodeling complex. We have performed whole exome- and mRNA-sequencing on an early onset AT/RT case for detection of genetic events potentially contributing to the disease.
RESULTS: A de novo germline variant in SMARCB1, c.601C>T p.Arg201∗, in combination with somatic deletion of the healthy allele is likely the major tumour causing event. Only seven somatic small scale mutations were discovered (hitting SEPT03, H2BFM, ZIC4, HIST2H2AB, ZIK1, KRTAP6-3, and IFNA8). All were found with subclonal allele frequencies (range 5.7-17%) and none were expressed. However, besides SMARCB1, candidate genes affected by predicted damaging germline variants that were expressed were detected (KDM5C, NUMA1, and PCM1). Analysis of differently expressed genes revealed many dysregulated pathways in the tumour, such as cell cycle, CXCR4 pathway, GPCR-signalling, and neuronal system. FGFR1, CXCR4, and MDK were upregulated and may represent possible drug targets.
CONCLUSION: The loss of SMARCB1 function leads to AT/RT development and deregulated genes and pathways. Additional predisposing events may however contribute. Studies utilizing NGS technologies in larger cohorts will probably identify recurrent genetic and epigenetic alterations and molecular subgroups with implications for clinical practice and development of targeted therapies.

Schwaab J, Knut M, Haferlach C, et al.
Limited duration of complete remission on ruxolitinib in myeloid neoplasms with PCM1-JAK2 and BCR-JAK2 fusion genes.
Ann Hematol. 2015; 94(2):233-8 [PubMed] Related Publications
Rearrangements of chromosome band 9p24 are known to be associated with JAK2 fusion genes, e.g., t(8;9)(p22;p24) with a PCM1-JAK2 and t(9;22)(p24;q11) with a BCR-JAK2 fusion gene, respectively. In association with myeloid neoplasms, the clinical course is aggressive, and in absence of effective conventional treatment options, long-term remission is usually only observed after allogeneic stem cell transplantation (ASCT). With the discovery of inhibitors of the JAK2 tyrosine kinase and based on encouraging in vitro and in vivo data, we treated two male patients with myeloid neoplasms and a PCM1-JAK2 or a BCR-JAK2 fusion gene, respectively, with the JAK1/JAK2 inhibitor ruxolitinib. After 12 months of treatment, both patients achieved a complete clinical, hematologic, and cytogenetic response. Non-hematologic toxicity was only grade 1 while no hematologic toxicity was observed. However, remission in both patients was only short-term, with relapse occurring after 18 and 24 months, respectively, making ASCT indispensable in both cases. This data highlight (1) the ongoing importance of cytogenetic analysis for the diagnostic work-up of myeloid neoplasms as it may guide targeted therapy and (2) remission under ruxolitinib may only be short-termed in JAK2 fusion genes but it may be an important bridging therapy prior to ASCT.

Bain BJ, Ahmad S
Should myeloid and lymphoid neoplasms with PCM1-JAK2 and other rearrangements of JAK2 be recognized as specific entities?
Br J Haematol. 2014; 166(6):809-17 [PubMed] Related Publications
Since the publication of the 2001 and 2008 World Health Organization classifications of tumours of haematopoietic and lymphoid tissues, there has been an increasing move towards classification of haematological neoplasms on the basis of the underlying molecular genetic disorder. In recent decades there have been a significant number of reports of haematological neoplasms with rearrangement of JAK2. Published data on such cases have therefore been analysed to determine if any specific entities could be identified. On the basis of this analysis, it is suggested that lymphoid and myeloid neoplasms associated with t(8;9)(p22;p24); PCM1-JAK2 fusion should be recognized as an entity. Furthermore, lymphoid and myeloid neoplasms associated respectively with t(9;12)(p24;p13); ETV6-JAK2 and with t(9;22)(p24;q11·2); BCR-JAK2 should be documented carefully in order to define their features more clearly and assess whether they can be recognized as entities. Identification of all these conditions is important because of the possibility of response to JAK2 inhibitors.

Chen X, Paranjape T, Stahlhut C, et al.
Targeted resequencing of the microRNAome and 3'UTRome reveals functional germline DNA variants with altered prevalence in epithelial ovarian cancer.
Oncogene. 2015; 34(16):2125-37 [PubMed] Free Access to Full Article Related Publications
Ovarian cancer is a major cause of cancer deaths, yet there have been few known genetic risk factors identified, the best known of which are disruptions in protein coding sequences (BRCA1 and 2). Recent findings indicate that there are powerful genetic markers of cancer risk outside of these regions, in the noncoding mRNA control regions. To identify additional cancer-associated, functional non-protein-coding sequence germline variants associated with ovarian cancer risk, we captured DNA regions corresponding to all validated human microRNAs and the 3' untranslated regions (UTRs) of ~6000 cancer-associated genes from 31 ovarian cancer patients. Multiple single-nucleotide polymorphisms in the 3'UTR of the vascular endothelial growth factor receptor/FLT1, E2F2 and PCM1 oncogenes were highly enriched in ovarian cancer patients compared with the 1000 Genome Project. Sequenom validation in a case-control study (267 cases and 89 controls) confirmed a novel variant in the PCM1 3'UTR is significantly associated with ovarian cancer (P=0.0086). This work identifies a potential new ovarian cancer locus and further confirms that cancer resequencing efforts should not ignore the study of noncoding regions of cancer patients.

Mwinyi J, Vokinger K, Jetter A, et al.
Impact of variable CYP genotypes on breast cancer relapse in patients undergoing adjuvant tamoxifen therapy.
Cancer Chemother Pharmacol. 2014; 73(6):1181-8 [PubMed] Related Publications
BACKGROUND: Tamoxifen is frequently used for the treatment of hormone receptor positive breast cancer (BC). Mainly CYP2D6 is responsible for the transformation to therapeutically active metabolites, but CYP2C19, CYP2C9 and CYP2B6 also are involved. We investigated the impact of polymorphisms within the genes encoding these CYP enzymes on the relapse-free time (RFT) in patients with BC.
METHODS: Ninety-nine patients with hormone receptor positive BC, who had undergone adjuvant tamoxifen therapy, were genotyped for seventeen common variants within the genes encoding CYP2D6, CYP2C9, CYP2C19 and CYP2B6 using TaqMan and PCR-RFLP technology. Kaplan-Meier and Cox regression analyses were performed to elucidate the impact of genetic variants on RFT. Furthermore, CYP2D6 metabolic activity was determined in a subset of 50 patients by assessing dextromethorphan/dextrorphan urinary excretion ratios. CYP2D6 activity was compared to the CYP2D6 allelic combinations to evaluate the predictive value of the CYP2D6 genotyping results on phenotype.
RESULTS: Although a trend toward longer RFTs in carriers of CYP2D6 allele combinations encoding for extensive and ultrafast metabolizer phenotypes was observed, none of the investigated genetic variants had a statistically significant impact on RFT. The combined analysis of five major CYP2D6 variants was useful for the discrimination between poor and non-poor metabolizers.
CONCLUSIONS: Comprehensive CYP2D6 genotyping has a good predictive value for CYP2D6 activity. Common variants in CYP2C9, CYP2C19, CYP2D6, and CYP2B6 did not have a significant impact on the RFT in this cohort of patients with BC.

Hsu TI, Lin SC, Lu PS, et al.
MMP7-mediated cleavage of nucleolin at Asp255 induces MMP9 expression to promote tumor malignancy.
Oncogene. 2015; 34(7):826-37 [PubMed] Related Publications
Nucleolin (NCL) participates in DNA transcription, ribosomal biogenesis and the regulation of RNA stability. However, the contribution of NCL to tumor development is still not clear. Herein, we found that NCL expression correlated with poor prognosis in lung cancer patients. Overexpressed NCL was predominantly cleaved to C-terminal truncated NCL (TNCL). In lung cancer formation, activation of the epidermal growth factor receptor pathway induced NCL expression, and also the expression of matrix metalloproteinase (MMP) 7, which then cleaved NCL at Asp255 to generate TNCL of 55 kDa. TNCL increased the expression of several oncogenes, including MMP9, anaplastic lymphoma kinase (ALK), HIF1a and CBLB, and decreased the expression of tumor suppressors including BRD4, PCM1, TFG and KLF6 by modulating mRNA stability through binding to the 3'-untranslated regions of their transcripts, thus ultimately enhancing metastasis activity. In conclusion, this study identified a novel role of the cleavage form of NCL generated by MMP7 in stabilizing MMP9 mRNA. We also provide a new insight that MMP7 not only cleaves the extracellular matrix to promote tumor invasion but also cleaves NCL, which augment oncogenesis. Blocking NCL cleavage may provide a useful new strategy for lung cancer therapy.

Chu Y, Wang Y, Zhang G, et al.
Chromatin composition alterations and the critical role of MeCP2 for epigenetic silencing of progesterone receptor-B gene in endometrial cancers.
Cell Mol Life Sci. 2014; 71(17):3393-408 [PubMed] Related Publications
OBJECTIVE: To understand the epigenetic mechanism underlying the PR-B gene silencing in endometrial cancer (EC) cells, we compared the chromatin composition between transcriptionally active and silenced PR-B genes in EC cell lines and cancer tissues.
METHODS: Chromatin Immunoprecipitation (ChIP) assay was performed to measure MBD occupancy and histone acetylation/methylation in transcriptionally active and silenced PR-B genes. PR-B-positive/-negative, as well as epigenetic inhibitor-treated/-untreated EC cells were used as study models. Real-time polymerase chain reaction (PCR) and Western blot analysis were applied to measure the mRNA and protein levels of PR-B, MBD, and histones.
RESULTS: A close association among PR-B methylation, MBD binding and PR-B gene silencing was observed. Treatment with epigenetic inhibitors led to dynamic changes in the PR-B chromatin composition and gene expression. Increased H3/H4 acetylation and H3-K4 methylation, and decreased H3-K9 methylation were found to be associated with re-activation of silenced PR-B genes. MeCP2 knockdown resulted in a decreased MeCP2 binding to PR-B genes and an increased PR-B expression. ChIP analysis of MeCP2 binding to PR-B genes in the PR-B-positive/-negative EC samples confirmed the significant role of MeCP2 in PR-B silencing.
CONCLUSION: PR-B gene expression is regulated by a concerted action of epigenetic factors including DNA methylation, MBD binding, and histone modifications. MeCP2 occupancy of PR-B genes plays a critical role in PR-B gene silencing. These findings enriched our knowledge of the epigenetic regulation of PR-B expression in EC, and suggested that the epigenetic re-activation of PR-B could be explored as a potential strategy to sensitize the PR-B-negative endometrial cancers to progestational therapy.

Ghersi D, Singh M
Interaction-based discovery of functionally important genes in cancers.
Nucleic Acids Res. 2014; 42(3):e18 [PubMed] Free Access to Full Article Related Publications
A major challenge in cancer genomics is uncovering genes with an active role in tumorigenesis from a potentially large pool of mutated genes across patient samples. Here we focus on the interactions that proteins make with nucleic acids, small molecules, ions and peptides, and show that residues within proteins that are involved in these interactions are more frequently affected by mutations observed in large-scale cancer genomic data than are other residues. We leverage this observation to predict genes that play a functionally important role in cancers by introducing a computational pipeline (http://canbind.princeton.edu) for mapping large-scale cancer exome data across patients onto protein structures, and automatically extracting proteins with an enriched number of mutations affecting their nucleic acid, small molecule, ion or peptide binding sites. Using this computational approach, we show that many previously known genes implicated in cancers are enriched in mutations within the binding sites of their encoded proteins. By focusing on functionally relevant portions of proteins--specifically those known to be involved in molecular interactions--our approach is particularly well suited to detect infrequent mutations that may nonetheless be important in cancer, and should aid in expanding our functional understanding of the genomic landscape of cancer.

Xu J, Zhu W, Xu W, et al.
Silencing of MBD1 reverses pancreatic cancer therapy resistance through inhibition of DNA damage repair.
Int J Oncol. 2013; 42(6):2046-52 [PubMed] Related Publications
High resistance to traditional chemo- and radiotherapies contributes to the poor prognosis of pancreatic cancer (PC). Methyl-CpG binding domain protein 1 (MBD1), which plays an important role in disease progression, contributes to the drug resistance of PC cells; however, the mechanism underlying the drug resistance endowed by MBD1 remains unknown. In this study, we found that MBD1 was recruited to DNA damage sites under DNA damage conditions. Silencing of MBD1 significantly impaired activation of the DNA damage checkpoint response and inhibited DNA repair capacity. MBD1 binds mediator of DNA damage checkpoint protein 1 (MDC1), which is induced by radiation and regulates NBS1 activation in the presence of DNA damage repair. Knockdown of MBD1 significantly increased the sensitivity of cells to radiation and cisplatin (diamindichloridoplatin, DDP) in vitro. Importantly, the function of MBD1 in regulating chemoradioresistance is also partially dependent on DNA damage repair. Thus, we hypothesize that MBD1 may promote PC chemoradioresistance by regulating PC cell fate in the presence of DNA damage. Collectively, these findings reveal an important function of MBD1 in DNA repair and mediation of chemoradioresistance of cancer cells. Moreover, this study suggests that MBD1 is a promising molecular target for sensitizing resistant PC tumor cells to chemoradiotherapy.

Hopman S, Merks J, Eussen H, et al.
Structural genome variations in individuals with childhood cancer and tumour predisposition syndromes.
Eur J Cancer. 2013; 49(9):2170-8 [PubMed] Related Publications
BACKGROUND: Previous studies have shown a high prevalence of syndromes in children with cancer. We described four patterns of co-occurring morphological abnormalities indicating new tumour predisposition syndromes. These patterns were named after their key-abnormalities: blepharophimosis (BP), epicanthal folds (EF), asymmetric lower limbs (LLA) and Sydney creases (SC) pattern. The purpose of our study was to identify structural genomic variants possibly involved in these tumour predisposition syndromes.
PATIENTS AND METHODS: In 49 probands (13 from BP, nine from EF, 20 from LLA and seven from SC patterns respectively) karyotyping was performed. Copy number variation (CNV) in genomic DNA of the probands was analysed to detect microdeletions/-duplications using SNP array. FISH and quantitative-polymerase chain reaction (q-PCR) experiments were done to validate events identified by cytogenetic and CNV analysis.
RESULTS: Cytogenetic analysis showed an inherited inversion of chromosome 15, inv(15) (q25q26) in a proband with LLA-pattern. Evaluation of the genes at the breakpoints made it unlikely that these explained the phenotype and tumour in this patient. Eleven CNV events met our inclusion criteria; three inherited CNV events involved an oncogene. A duplication involving BCL9 was identified in a proband diagnosed with Burkitt lymphoma. A duplication involving PCM1 was identified in a proband diagnosed with pre-B-ALL. Both probands showed the EF-pattern of morphological abnormalities. A deletion involving TRA@ was identified in two probands from the BP-pattern diagnosed with rhabdomyosarcoma and pre-B-ALL respectively.
CONCLUSIONS: We report on structural genomic variants in paediatric cancer patients with newly recognised tumour predisposition syndromes. We identify three CNV events which we suggest to be susceptibility loci.

Velpula KK, Gogineni VR, Nalla AK, et al.
Radiation-induced hypomethylation triggers urokinase plasminogen activator transcription in meningioma cells.
Neoplasia. 2013; 15(2):192-203 [PubMed] Free Access to Full Article Related Publications
Our previous studies have shown the role of radiation-induced urokinase plasminogen activator (uPA) expression in the progression of meningioma. In the present study, we investigated whether modulation of DNA methylation profiles could regulate uPA expression. Initially, radiation treatment was found to induce hypomethylation in meningioma cells with a decrease in DNA (cytosine-5)-methyltransferase 1 (DNMT1) and methyl-CpG binding domain protein (MBD) expression. However, oxidative damage by H(2)O(2) or pretreatment of irradiated cells with N-acetyl cysteine (NAC) did not show any influence on these proteins, thereby indicating a radiation-specific change in the methylation patterns among meningioma cells. Further, we identified that hypomethylation is coupled to an increase in uPA expression in these cells. Azacytidine treatment induced a dose-dependent surge of uPA expression, whereas pre-treatment with sodium butyrate inhibited radiation-induced uPA expression, which complemented our prior results. Methylation-specific polymerase chain reaction on bisulfite-treated genomic DNA revealed a diminished methylation of uPA promoter in irradiated cells. Transfection with small hairpin RNA (shRNA)-expressing plasmids targeting CpG islands of the uPA promoter showed a marked decline in uPA expression with subsequent decrease in invasion and proliferation of meningioma cells. Further, radiation treatment was found to recruit SP1 transcription factor, which was abrogated by shRNA treatment. Analysis on signaling events demonstrated the activation of MAP kinase kinase (MEK)-extracellular signal-regulated kinase (ERK) in radiation-treated cells, while U0126 (MEK/ERK inhibitor) blocked hypomethylation, recruitment of SP1, and uPA expression. In agreement with our in vitro data, low DNMT1 levels and high uPA were found in intracranial tumors treated with radiation compared to untreated tumors. In conclusion, our data suggest that radiation-mediated hypomethylation triggers uPA expression in meningioma cells.

Patterer V, Schnittger S, Kern W, et al.
Hematologic malignancies with PCM1-JAK2 gene fusion share characteristics with myeloid and lymphoid neoplasms with eosinophilia and abnormalities of PDGFRA, PDGFRB, and FGFR1.
Ann Hematol. 2013; 92(6):759-69 [PubMed] Related Publications
The translocation t(8;9)(p22;p24) is a rare event that results in the fusion of JAK2 to PCM1 and thus leads to the activation of the Janus Kinase 2. In 2008, the WHO introduced a new entity called "Myeloid and lymphoid neoplasms with eosinophilia and abnormalities of PDGFRA, PDGFRB or FGFR1", which are characterized by the formation of a fusion gene encoding an aberrant tyrosine kinase. These disorders share characteristics with myeloproliferative neoplasms and typically show an eosinophilia. We here now report on 6 new cases with PCM1-JAK2 fusion. These patients show characteristics with respect to epidemiology, clinical presentation, and genetic changes that are very similar to patients with rearrangements of PDGFRA, PDGFRB, or FGFR1. Our data suggests the integration of cases with JAK2-PCM1 fusion in the respective WHO category of myeloid and lymphoid neoplasms with eosinophilia and abnormalities of PDGFRA, PDGFRB, or FGFR1.

Ehrentraut S, Nagel S, Scherr ME, et al.
t(8;9)(p22;p24)/PCM1-JAK2 activates SOCS2 and SOCS3 via STAT5.
PLoS One. 2013; 8(1):e53767 [PubMed] Free Access to Full Article Related Publications
Fusions of the tyrosine kinase domain of JAK2 with multiple partners occur in leukemia/lymphoma where they reportedly promote JAK2-oligomerization and autonomous signalling, Affected entities are promising candidates for therapy with JAK2 signalling inhibitors. While JAK2-translocations occur in myeloid, B-cell and T-cell lymphoid neoplasms, our findings suggest their incidence among the last group is low. Here we describe the genomic, transcriptional and signalling characteristics of PCM1-JAK2 formed by t(8;9)(p22;p24) in a trio of cell lines established at indolent (MAC-1) and aggressive (MAC-2A/2B) phases of a cutaneous T-cell lymphoma (CTCL). To investigate signalling, PCM1-JAK2 was subjected to lentiviral knockdown which inhibited 7 top upregulated genes in t(8;9) cells, notably SOCS2/3. SOCS3, but not SOCS2, was also upregulated in a chronic eosinophilic leukemia bearing PCM1-JAK2, highlighting its role as a central signalling target of JAK2 translocation neoplasia. Conversely, expression of GATA3, a key T-cell developmental gene silenced in aggressive lymphoma cells, was partially restored by PCM1-JAK2 knockdown. Treatment with a selective JAK2 inhibitor (TG101348) to which MAC-1/2A/2B cells were conspicuously sensitive confirmed knockdown results and highlighted JAK2 as the active moiety. PCM1-JAK2 signalling required pSTAT5, supporting a general paradigm of STAT5 activation by JAK2 alterations in lymphoid malignancies. MAC-1/2A/2B--the first JAK2-translocation leukemia/lymphoma cell lines described--display conspicuous JAK/STAT signalling accompanied by T-cell developmental and autoimmune disease gene expression signatures, confirming their fitness as CTCL disease models. Our data support further investigation of SOCS2/3 as signalling effectors, prognostic indicators and potential therapeutic targets in cancers with JAK2 rearrangements.

Xu J, Zhu W, Xu W, et al.
Up-regulation of MBD1 promotes pancreatic cancer cell epithelial-mesenchymal transition and invasion by epigenetic down-regulation of E-cadherin.
Curr Mol Med. 2013; 13(3):387-400 [PubMed] Related Publications
Methyl-CpG binding domain protein 1 (MBD1) has been implicated in transcriptional regulation, heterochromatin formation, genomic stability, cell-cycle progression and development. It is also predicted that MBD1 might be involved in tumor development and progression. However, whether and how MBD1 is involved in tumorigenesis, especially in pancreatic cancer (PC), is currently unknown. We found that MBD1 was significantly up-regulated in PC tissues compared with the surrounding normal tissues according to RT-PCR data. Tissue microarray (TMA) based immunohistochemical study from 58 surgically resected PC specimens indicated that higher MBD1 expression correlated with lymph node metastasis and poor survival in PC patients. Gain- and loss-of-function studies in vitro validated MBD1 as a potent oncogene promoting PC cell invasion as well as epithelial-mesenchymal transition (EMT). Mechanistically, MBD1 is associated with Twist and NAD-dependent deacetylase sirtuin-1 (SIRT1), thereby forming the Twist-MBD1-SIRT1 complex on the CDH1 promoter, which resulted in reduced E-cadherin transcription activity and increased cell EMT ability. Significantly, targeting MBD1 reversed the EMT phenotype of PC and restored sensitivity to chemotherapy. Taken together, the results of our study revealed a novel function of MBD1 in PC invasion and metastasis by providing a molecular mechanism underlying MBD1-promoted EMT. Thus MBD1 may serve as a potential therapeutic target for PC.

Solyom S, Ewing AD, Rahrmann EP, et al.
Extensive somatic L1 retrotransposition in colorectal tumors.
Genome Res. 2012; 22(12):2328-38 [PubMed] Free Access to Full Article Related Publications
L1 retrotransposons comprise 17% of the human genome and are its only autonomous mobile elements. Although L1-induced insertional mutagenesis causes Mendelian disease, their mutagenic load in cancer has been elusive. Using L1-targeted resequencing of 16 colorectal tumor and matched normal DNAs, we found that certain cancers were excessively mutagenized by human-specific L1s, while no verifiable insertions were present in normal tissues. We confirmed de novo L1 insertions in malignancy by both validating and sequencing 69/107 tumor-specific insertions and retrieving both 5' and 3' junctions for 35. In contrast to germline polymorphic L1s, all insertions were severely 5' truncated. Validated insertion numbers varied from up to 17 in some tumors to none in three others, and correlated with the age of the patients. Numerous genes with a role in tumorigenesis were targeted, including ODZ3, ROBO2, PTPRM, PCM1, and CDH11. Thus, somatic retrotransposition may play an etiologic role in colorectal cancer.

Gopisetty G, Xu J, Sampath D, et al.
Epigenetic regulation of CD133/PROM1 expression in glioma stem cells by Sp1/myc and promoter methylation.
Oncogene. 2013; 32(26):3119-29 [PubMed] Free Access to Full Article Related Publications
Tumor stem cells, postulated to be the source cells for malignancies, have been identified in several cancers using cell-surface expression of markers including CD133, a pentaspan membrane protein. CD133+ve cells form neurospheres, exhibit self-renewal and differentiation, and are tumorigenic. However, despite its association with stem cells, a causal relationship of CD133 to tumorigenesis remains to be defined. Hypothesizing that specific epigenetic and transcription factors implicated in driving the stem cell state may concurrently regulate CD133 expression in stem cells, we analyzed the structure and regulation of CD133 promoter in glioma stem cells and glioma cell lines. Initially, a minimal promoter region was identified by analyzing the activity of CD133 promoter-driven luciferase-expressing 5'-and 3'-deletion-constructs upstream of the transcription start site. This region contained a CpG island that was hypermethylated in CD133-ve glioma stem cells (GSC) and glioma cells but unmethylated in CD133+ve ones. Of several predicted TF-binding sites in this region, the role of tandem Sp1 (-242 and -221) and two Myc (-541 and -25)-binding sites were examined. Overexpression of Sp1 or Myc increased CD133 minimal promoter-driven luciferase activity and CD133 levels in GSC and in glioma cell line. Mithramycin, a Sp1 inhibitor, decreased minimal promoter activity and downregulated CD133 levels in GSC. Gel-shift assays demonstrated direct binding of Sp1 to their predicted sites that was competitively inhibited by oligonucleotide-binding-site sequences and supershifted by anti-Sp1 confirming the interaction. Sp1 and Myc-antibody chromatin immunoprecipitation (ChIP) analysis in GSC showed enrichment of regions with Sp1 and Myc-binding sites. In CD133-ve cells, ChIP analysis showed binding of the methyl-DNA-binding proteins, MBD1, MBD2 and MeCP2 to the methylated CpG island and repression of transcription. These results demonstrate that Sp1 and Myc regulate CD133 transcription in GSC and that promoter methylation and methyl-DNA-binding proteins cause repression of CD133 by excluding transcription-factor binding.

Harlid S, Ivarsson MI, Butt S, et al.
A candidate CpG SNP approach identifies a breast cancer associated ESR1-SNP.
Int J Cancer. 2011; 129(7):1689-98 [PubMed] Related Publications
Altered DNA methylation is often seen in malignant cells, potentially contributing to carcinogenesis by suppressing gene expression. We hypothesized that heritable methylation potential might be a risk factor for breast cancer and evaluated possible association with breast cancer for single nucleotide polymorphisms (SNPs) either involving CpG sequences in extended 5'-regulatory regions of candidate genes (ESR1, ESR2, PGR, and SHBG) or CpG and missense coding SNPs in genes involved in methylation (MBD1, MECP2, DNMT1, MGMT, MTHFR, MTR, MTRR, MTHFD1, MTHFD2, BHMT, DCTD, and SLC19A1). Genome-wide searches for genetic risk factors for breast cancers have in general not investigated these SNPs, because of low minor allele frequency or weak haplotype associations. Genotyping was performed using Mass spectrometry-Maldi-Tof in a screening panel of 538 cases and 1,067 controls. Potential association to breast cancer was identified for 15 SNPs and one of these SNPs (rs7766585 in ESR1) was found to associate strongly with breast cancer, OR 1.30 (95% CI 1.17-1.45; p-value 2.1 × 10(-6)), when tested in a verification panel consisting of 3,211 unique breast cancer cases and 4,223 unique controls from five European biobank cohorts. In conclusion, a candidate gene search strategy focusing on methylation-related SNPs did identify a SNP that associated with breast cancer at high significance.

Hoeller S, Walz C, Reiter A, et al.
PCM1-JAK2-fusion: a potential treatment target in myelodysplastic-myeloproliferative and other hemato-lymphoid neoplasms.
Expert Opin Ther Targets. 2011; 15(1):53-62 [PubMed] Related Publications
IMPORTANCE OF THE FIELD: Activating mutations of the JAK2 gene are of tumorigenic significance in myeloproliferative neoplasms. Translocations involving the JAK2 locus are of oncogenic importance in acute leukemias, myelodysplastic/myeloproliferative diseases and T-cell lymphomas. JAK2 locus gains, which are recurrent in Hodgkin's- and primary mediastinal B-cell lymphoma, are also efficient mechanisms of JAK2 activation. Recently, specific drugs blocking JAK2 have been developed and are currently in clinical trials.
AREAS COVERED IN THIS REVIEW: We discuss possible mechanisms of deregulation and the significance of pericentriolar material 1 (PCM)1-JAK2 fusion/t(8;9)(p21-23;p23-24) in hematolymphoid neoplasms. Such cases show morphological (myeloproliferaton, eosinophilia, myelofibrosis) and clinical (striking male predominance, aggressive course) similarities. Since increased JAK2 oligomerization and tyrosine kinase domain activation is the probable oncogenic mechanism in this instance, such patients are promising candidates for JAK2 inhibitor therapy.
WHAT THE READER WILL GAIN: The reader will gain important insights considering PCM1-JAK2 fusion in hematologic malignancies.
TAKE HOME MESSAGE: JAK2 is a tyrosine kinase with oncogenic potential in hematologic malignancies. It can be activated by point mutations, translocations and amplifications. Beyond malignancies associated with JAK2 point mutations, those associated with translocations might be suitable for tyrosine kinase inhibitors, which merits prospective evaluation.

Chen Y, Luo J, Tian R, et al.
miR-373 negatively regulates methyl-CpG-binding domain protein 2 (MBD2) in hilar cholangiocarcinoma.
Dig Dis Sci. 2011; 56(6):1693-701 [PubMed] Related Publications
BACKGROUND: microRNAs (miRNAs) are a class of non-coding, single-stranded RNA molecules that regulate gene expression at the posttranscriptional level. Methyl-CpG-binding domain proteins (MBPs) are transcription repressors through binding to methylated gene promoters. Recent studies have shown that the effect of miRNAs on DNA methylation by targeting DNA methyltransferase (DNMTs) and/or MBPs plays an important role in various human cancers.
AIMS: This study focuses on the regulation of MBPs by miR-373 and its downstream effect in hilar cholangiocarcinoma.
METHODS: miR-373 was investigated by TaqMan miRNA Assay; mRNA and protein of MBD1, MBD2, and Mecp2 were determined by QuantiTect(®) Primer Assays and Western blotting, respectively; RASSF1A mRNA was measured by SYBR-Green real-time PCR; The targeting at MBD2-3'UTR by miR-373 was evaluated by dual-luciferase reporter gene assay.
RESULTS: miR-373 decreased and closely associated with poor cell differentiation, advanced clinical stage, and shorter survival in hilar cholangiocarcinoma; MBD2 exclusively over-expressed and reciprocally related to miR-373; precursor miR-373 inhibited the luciferase activity of MBD2-3'UTR construct; exogenous miR-373 suppressed the expression of MBD2 and enhanced RASSF1A mRNA in QBC(939) cells; anti-miR-373 inhibitor up-regulated the expression of MBD2 and reduced RASSF1A mRNA in HIBEpic cells.
CONCLUSIONS: miR-373 is one negative regulator of MBD2. In hilar cholangiocarcinoma, down-expression of miR-373 leads to increase of MBD2, which in turn suppresses the methylation-mediated gene such as RASSF1A.

Nair SS, Coolen MW, Stirzaker C, et al.
Comparison of methyl-DNA immunoprecipitation (MeDIP) and methyl-CpG binding domain (MBD) protein capture for genome-wide DNA methylation analysis reveal CpG sequence coverage bias.
Epigenetics. 2011; 6(1):34-44 [PubMed] Related Publications
DNA methylation primarily occurs at CpG dinucleotides in mammals and is a common epigenetic mark that plays a critical role in the regulation of gene expression. Profiling DNA methylation patterns across the genome is vital to understand DNA methylation changes that occur during development and in disease phenotype. In this study, we compared two commonly used approaches to enrich for methylated DNA regions of the genome, namely methyl-DNA immunoprecipitation (MeDIP) that is based on enrichment with antibodies specific for 5'-methylcytosine (5MeC), and capture of methylated DNA using a methyl-CpG binding domain-based (MBD) protein to discover differentially methylated regions (DMRs) in cancer. The enriched methylated DNA fractions were interrogated on Affymetrix promoter tiling arrays and differentially methylated regions were identified. A detailed validation study of 42 regions was performed using Sequenom MassCLEAVE technique. This detailed analysis revealed that both enrichment techniques are sensitive for detecting DMRs and preferentially identified different CpG rich regions of the prostate cancer genome, with MeDIP commonly enriching for methylated regions with a low CpG density, while MBD capture favors regions of higher CpG density and identifies the greatest proportion of CpG islands. This is the first detailed validation report comparing different methylated DNA enrichment techniques for identifying regions of differential DNA methylation. Our study highlights the importance of understanding the nuances of the methods used for DNA genome-wide methylation analyses so that accurate interpretation of the biology is not overlooked.

Müller I, Wischnewski F, Pantel K, Schwarzenbach H
Promoter- and cell-specific epigenetic regulation of CD44, Cyclin D2, GLIPR1 and PTEN by methyl-CpG binding proteins and histone modifications.
BMC Cancer. 2010; 10:297 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: The aim of the current study was to analyze the involvement of methyl-CpG binding proteins (MBDs) and histone modifications on the regulation of CD44, Cyclin D2, GLIPR1 and PTEN in different cellular contexts such as the prostate cancer cells DU145 and LNCaP, and the breast cancer cells MCF-7. Since global chromatin changes have been shown to occur in tumours and regions of tumour-associated genes are affected by epigenetic modifications, these may constitute important regulatory mechanisms for the pathogenesis of malignant transformation.
METHODS: In DU145, LNCaP and MCF-7 cells mRNA expression levels of CD44, Cyclin D2, GLIPR1 and PTEN were determined by quantitative RT-PCR at the basal status as well as after treatment with demethylating agent 5-aza-2'-deoxycytidine and/or histone deacetylase inhibitor Trichostatin A. Furthermore, genomic DNA was bisulfite-converted and sequenced. Chromatin immunoprecipitation was performed with the stimulated and unstimulated cells using antibodies for MBD1, MBD2 and MeCP2 as well as 17 different histone antibodies.
RESULTS: Comparison of the different promoters showed that MeCP2 and MBD2a repressed promoter-specifically Cyclin D2 in all cell lines, whereas in MCF-7 cells MeCP2 repressed cell-specifically all methylated promoters. Chromatin immunoprecipitation showed that all methylated promoters associated with at least one MBD. Treatment of the cells by the demethylating agent 5-aza-2'-deoxycytidine (5-aza-CdR) caused dissociation of the MBDs from the promoters. Only MBD1v1 bound and repressed methylation-independently all promoters. Real-time amplification of DNA immunoprecipitated by 17 different antibodies showed a preferential enrichment for methylated lysine of histone H3 (H3K4me1, H3K4me2 and H3K4me3) at the particular promoters. Notably, the silent promoters were associated with unmodified histones which were acetylated following treatment by 5-aza-CdR.
CONCLUSIONS: This study is one of the first to reveal the histone code and MBD profile at the promoters of CD44, Cyclin D2, GLIPR1 and PTEN in different tumour cells and associated changes after stimulation with methylation inhibitor 5-aza-CdR.

Pandey M, Shukla S, Gupta S
Promoter demethylation and chromatin remodeling by green tea polyphenols leads to re-expression of GSTP1 in human prostate cancer cells.
Int J Cancer. 2010; 126(11):2520-33 [PubMed] Free Access to Full Article Related Publications
Epigenetic silencing of gluthathione-S-transferase pi (GSTP1) is recognized as being a molecular hallmark of human prostate cancer. We investigated the effects of green tea polyphenols (GTPs) on GSTP1 re-expression and further elucidated its mechanism of action and long-term safety, compared with nucleoside-analog inhibitor of DNA methyltransferase (DNMT), 5-aza-2'-deoxycitidine. Exposure of human prostate cancer LNCaP cells to 1-10 microg/ml of GTP for 1-7 days caused a concentration- and time-dependent re-expression of GSTP1, which correlated with DNMT1 inhibition. Methyl-specific-PCR and sequencing revealed extensive demethylation in the proximal GSTP1 promoter and regions distal to the transcription factor binding sites. GTP exposure in a time-dependent fashion diminished the mRNA and protein levels of MBD1, MBD4 and MeCP2; HDAC 1-3 and increased the levels of acetylated histone H3 (LysH9/18) and H4. Chromatin immunoprecipitation assays demonstrated that cells treated with GTP have reduced MBD2 association with accessible Sp1 binding sites leading to increased binding and transcriptional activation of the GSTP1 gene. Exposure of cells to GTP did not result in global hypomethylation, as demonstrated by methyl-specific PCR for LINE-1 promoter; rather GTP promotes maintenance of genomic integrity. Furthermore, exposure of cells to GTP did not cause activation of the prometaststic gene S100P, a reverse response noted after exposure of cells to 5-aza-2'deoxycitidine. Our results, for the first time, demonstrate that GTP has dual potential to alter DNA methylation and chromatin modeling, the 2 global epigenetic mechanisms of gene regulation and their lack of toxicity makes them excellent candidates for the chemoprevention of prostate cancer.

Derks S, Bosch LJ, Niessen HE, et al.
Promoter CpG island hypermethylation- and H3K9me3 and H3K27me3-mediated epigenetic silencing targets the deleted in colon cancer (DCC) gene in colorectal carcinogenesis without affecting neighboring genes on chromosomal region 18q21.
Carcinogenesis. 2009; 30(6):1041-8 [PubMed] Related Publications
Chromosomal loss of 18q21 is a frequent event in colorectal cancer (CRC) development, suggesting that this region harbors tumor suppressor genes (TSGs). Several candidate TSGs, among which methyl-CpG-binding domain protein 1 (MBD1), CpG-binding protein CXXC1, Sma- and Mad-related protein 4 (SMAD4), deleted in colon cancer (DCC) and methyl-CpG-binding domain protein 2 (MBD2) are closely linked on a 4-Mb DNA region on chromosome18q21. As TSGs can be epigenetically silenced, this study investigates whether MBD1, CXXC1, SMAD4, DCC and MBD2 are subject to epigenetic silencing in CRC. Methylation-specific polymerase chain reaction and sodium bisulfite sequencing of these genes show that DCC, but not MBD1, CXXC1, SMAD4 and MBD2, has promoter CpG island methylation in CRC cell lines and tissues {normal mucosa [29.5% (18/61)], adenomas [81.0% (47/58)] and carcinomas [82.7% (62/75)] (P = 8.6 x 10(-9))} that is associated with reduced DCC expression, independent of 18q21 loss analyzed by multiplex ligation-dependent probe amplification. Reduced gene expression of CXXC1, SMAD4 and MBD2 correlates with 18q21 loss in CRC cell lines (P = 0.04, 0.02 and 0.02, respectively). Treatment with the demethylating agent 5-aza-2'-deoxycytidine, but not with the histone deacetylase inhibitor trichostatin A exclusively restored DCC expression in CRC cell lines. Chromatin immunoprecipitation studies reveal that the DCC promoter is marked with repressive histone-tail marks H3K9me3 and H3K27me3, whereas activity related H3K4me3 was absent. Only active epigenetic marks were detected for MBD1, CXXC1, SMAD4 and MBD2. This study demonstrates specific epigenetic silencing of DCC in CRC as a focal process not affecting neighboring genes on chromosomal region 18q21.

Luo G, Jin C, Long J, et al.
RNA interference of MBD1 in BxPC-3 human pancreatic cancer cells delivered by PLGA-poloxamer nanoparticles.
Cancer Biol Ther. 2009; 8(7):594-8 [PubMed] Related Publications
Methyl-CpG binding domain protein 1 (MBD1) is a transcriptional regulator that binds methylated CpG islands of tumor suppressor genes and represses their transcription. In a former study, we found high expression of MBD1 in pancreatic cancer cell lines and tissues which may play an important role in the development of pancreatic cancer. In the present study, we incorporated the siRNA sequence of MBD1 plasmid into a PLGA-poloxamer carrier to test the therapeutic effect of this compound on BxPC-3 human pancreatic cancer cells. We found that an MBD1 siRNA plasmid can be successfully transfected into tumor cells and the MBD1 nanoparticle compound can inhibit cell growth and induce apoptosis. The MBD1 nanoparticle is a promising candidate for gene therapy of pancreatic cancer in vitro.

Tabarés-Seisdedos R, Rubenstein JL
Chromosome 8p as a potential hub for developmental neuropsychiatric disorders: implications for schizophrenia, autism and cancer.
Mol Psychiatry. 2009; 14(6):563-89 [PubMed] Related Publications
Defects in genetic and developmental processes are thought to contribute susceptibility to autism and schizophrenia. Presumably, owing to etiological complexity identifying susceptibility genes and abnormalities in the development has been difficult. However, the importance of genes within chromosomal 8p region for neuropsychiatric disorders and cancer is well established. There are 484 annotated genes located on 8p; many are most likely oncogenes and tumor-suppressor genes. Molecular genetics and developmental studies have identified 21 genes in this region (ADRA1A, ARHGEF10, CHRNA2, CHRNA6, CHRNB3, DKK4, DPYSL2, EGR3, FGF17, FGF20, FGFR1, FZD3, LDL, NAT2, NEF3, NRG1, PCM1, PLAT, PPP3CC, SFRP1 and VMAT1/SLC18A1) that are most likely to contribute to neuropsychiatric disorders (schizophrenia, autism, bipolar disorder and depression), neurodegenerative disorders (Parkinson's and Alzheimer's disease) and cancer. Furthermore, at least seven nonprotein-coding RNAs (microRNAs) are located at 8p. Structural variants on 8p, such as copy number variants, microdeletions or microduplications, might also contribute to autism, schizophrenia and other human diseases including cancer. In this review, we consider the current state of evidence from cytogenetic, linkage, association, gene expression and endophenotyping studies for the role of these 8p genes in neuropsychiatric disease. We also describe how a mutation in an 8p gene (Fgf17) results in a mouse with deficits in specific components of social behavior and a reduction in its dorsomedial prefrontal cortex. We finish by discussing the biological connections of 8p with respect to neuropsychiatric disorders and cancer, despite the shortcomings of this evidence.

Liu L, Ishihara K, Ichimura T, et al.
MCAF1/AM is involved in Sp1-mediated maintenance of cancer-associated telomerase activity.
J Biol Chem. 2009; 284(8):5165-74 [PubMed] Related Publications
Telomerase maintains telomere length and is implicated in senescence and immortalization of mammalian cells. Two essential components for this enzyme are telomerase reverse transcriptase (TERT) and the telomerase RNA component (encoded by the TERC gene). These telomerase subunit genes are known to be mainly expressed by specificity protein 1 (Sp1). MBD1-containing chromatin-associated factor 1 (MCAF1), also known as ATFa-associated modulator (AM) and activating transcription factor 7-interacting protein (ATF7IP), mediates gene regulation, although the precise function of MCAF1 remains to be elucidated. Here, we report that MCAF1 is involved in Sp1-dependent maintenance of telomerase activity in cancer cells. Two evolutionarily conserved domains of MCAF1 directly interact with Sp1 and the general transcriptional apparatus. Selective depletion of MCAF1 or Sp1 down-regulates TERT and TERC genes in cultured cells, which results in decreased telomerase activity. The transcriptionally active form of RNA polymerase II and the general transcription factor ERCC3 decreased in the TERT promoter under the loss of MCAF1 or Sp1. Consistently, MCAF1 is found to be frequently overexpressed in naturally occurring cancers that originate in different tissues. Our data suggest that transcriptional function of MCAF1 facilitates telomerase expression by Sp1, which may be a common mechanism in proliferative cancer cells.

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