Gene Summary

Gene:PEA15; phosphoprotein enriched in astrocytes 15
Aliases: PED, MAT1, HMAT1, MAT1H, PEA-15, HUMMAT1H
Summary:This gene encodes a death effector domain-containing protein that functions as a negative regulator of apoptosis. The encoded protein is an endogenous substrate for protein kinase C. This protein is also overexpressed in type 2 diabetes mellitus, where it may contribute to insulin resistance in glucose uptake. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2014]
Databases:OMIM, VEGA, HGNC, Ensembl, GeneCard, Gene
Protein:astrocytic phosphoprotein PEA-15
Source:NCBIAccessed: 06 August, 2015


What does this gene/protein do?
Show (10)

Cancer Overview

Research Indicators

Publications Per Year (1990-2015)
Graph generated 06 August 2015 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.

  • Brain Tumours
  • Lung Cancer
  • Xenograft Models
  • Tumor Suppressor Proteins
  • TNF
  • Ovarian Cancer
  • Phosphorylation
  • Apoptosis Regulatory Proteins
  • CASP8
  • Ribosomal Protein S6 Kinases, 90-kDa
  • Mitogen-Activated Protein Kinase 1
  • Protein Binding
  • Caspases
  • Neoplastic Cell Transformation
  • Base Sequence
  • Brain Tumours
  • Chromosome 1
  • Western Blotting
  • Gene Expression Profiling
  • Enzyme Activation
  • Oligonucleotide Array Sequence Analysis
  • Intracellular Signaling Peptides and Proteins
  • Mitogen-Activated Protein Kinase 3
  • Caspase 8
  • Apoptosis
  • Non-Small Cell Lung Cancer
  • Glioblastoma
  • MicroRNAs
  • Cell Proliferation
  • Transfection
  • Down-Regulation
  • Cancer RNA
  • Phosphoproteins
  • Drug Resistance
  • RNA Interference
  • TNF-Related Apoptosis-Inducing Ligand
  • Messenger RNA
  • Tumor Markers
  • Transduction
  • Cancer Gene Expression Regulation
  • HEK293 Cells
Tag cloud generated 06 August, 2015 using data from PubMed, MeSH and CancerIndex

Specific Cancers (5)

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: PEA15 (cancer-related)

Shin M, Lee KE, Yang EG, et al.
PEA-15 facilitates EGFR dephosphorylation via ERK sequestration at increased ER-PM contacts in TNBC cells.
FEBS Lett. 2015; 589(9):1033-9 [PubMed] Related Publications
Phosphoprotein enriched in astrocytes of 15 kDa (PEA-15) is known to sequester extracellular signal-regulated kinase (ERK) in the cytoplasm, inhibiting tumorigenesis of human breast cancer cells. Here, we describe how PEA-15 expression affects the dephosphorylation of epidermal growth factor receptor (EGFR) through endoplasmic reticulum (ER)-plasma membrane (PM) contacts in MDA-MB-468, triple-negative breast cancer (TNBC) cells. The increased intracellular calcium concentration resulting from increased cytoplasmic phosphorylated ERK facilitates movement of ER-anchored calcium sensors to the PM. The driving force of trans-localization of calcium-dependent proteins enhances the contact between the activated EGFR and ER-localized phosphatase, PTP1B. Consequently, our findings suggest a mechanism underneath the facilitation of EGFR dephosphorylation by cytoplasmic PEA-15 expression inside TNBC cells, which may be one of the dynamic mechanisms for down-regulation of activated EGFR in cancer cells.

Xie X, Tang H, Liu P, et al.
Development of PEA-15 using a potent non-viral vector for therapeutic application in breast cancer.
Cancer Lett. 2015; 356(2 Pt B):374-81 [PubMed] Related Publications
Advanced breast cancer requires systemic treatment, therefore developing an efficient and safe strategy is urgently needed. To ensure the success of target therapy, we have developed a breast cancer-specific construct (T-VISA) composed of the human telomerase reverse transcriptase (hTERT; T) promoter and a versatile transgene amplification vector VISA (VP16-GAL4-WPRE integrated systemic amplifier) to target PEA-15 (phosphoprotein enriched in astrocytes) in advanced breast tumors. PEA-15 contains a death effector domain that sequesters extracellular signal-regulated kinase (ERK) in the cytoplasm, thereby inhibiting cell proliferation and inducing apoptosis. T-VISA-PEA-15 was found to be highly specific, selectively express PEA-15 in breast cancer cells, and induce cancer-cell killing in vitro and in vivo without affecting normal cells. Moreover, intravenous treatment with T-VISA-PEA-15 coupled with liposome nanoparticles attenuated tumor growth and prolonged survival in mice bearing advanced breast tumors. Importantly, there was virtually no severe toxicity when PEA-15 is expressed by our T-VISA system compared with cytomegalovirus (CMV) promoter. Thus, our findings demonstrate an effective cancer-targeted therapy that is worthy of development in clinical trials eradicating advanced breast cancer.

Nagarajan A, Dogra SK, Liu AY, et al.
PEA15 regulates the DNA damage-induced cell cycle checkpoint and oncogene-directed transformation.
Mol Cell Biol. 2014; 34(12):2264-82 [PubMed] Free Access to Full Article Related Publications
Regulation of the DNA damage response and cell cycle progression is critical for maintaining genome integrity. Here, we report that in response to DNA damage, COPS5 deubiquitinates and stabilizes PEA15 in an ATM kinase-dependent manner. PEA15 expression oscillates throughout the cell cycle, and the loss of PEA15 accelerates cell cycle progression by activating CDK6 expression via the c-JUN transcription factor. Cells lacking PEA15 exhibit a DNA damage-induced G2/M checkpoint defect due to increased CDC25C activity and, consequentially, higher cyclin-dependent kinase 1 (CDK1)/cyclin B activity, and accordingly they have an increased rate of spontaneous mutagenesis. We find that oncogenic RAS inhibits PEA15 expression and that ectopic PEA15 expression blocks RAS-mediated transformation, which can be partially rescued by ectopic expression of CDK6. Finally, we show that PEA15 expression is downregulated in colon, breast, and lung cancer samples. Collectively, our results demonstrate that tumor suppressor PEA15 is a regulator of genome integrity and is an integral component of the DNA damage response pathway that regulates cell cycle progression, the DNA-damage-induced G2/M checkpoint, and cellular transformation.

Wallez Y, Riedl SJ, Pasquale EB
Association of the breast cancer antiestrogen resistance protein 1 (BCAR1) and BCAR3 scaffolding proteins in cell signaling and antiestrogen resistance.
J Biol Chem. 2014; 289(15):10431-44 [PubMed] Free Access to Full Article Related Publications
Most breast cancers are estrogen receptor-positive and treated with antiestrogens, but aberrant signaling networks can induce drug resistance. One of these networks involves the scaffolding protein BCAR1/p130CAS, which regulates cell growth and migration/invasion. A less investigated scaffolding protein that also confers antiestrogen resistance is the SH2 domain-containing protein BCAR3. BCAR1 and BCAR3 bind tightly to each other through their C-terminal domains, thus potentially connecting their associated signaling networks. However, recent studies using BCAR1 and BCAR3 interaction mutants concluded that association between the two proteins is not critical for many of their interrelated activities regulating breast cancer malignancy. We report that these previously used BCAR mutations fail to cause adequate loss-of-function of the complex. By using structure-based BCAR1 and BCAR3 mutants that lack the ability to interact, we show that BCAR3-induced antiestrogen resistance in MCF7 breast cancer cells critically depends on its ability to bind BCAR1. Interaction with BCAR3 increases the levels of phosphorylated BCAR1, ultimately potentiating BCAR1-dependent antiestrogen resistance. Furthermore, antiestrogen resistance in cells overexpressing BCAR1/BCAR3 correlates with increased ERK1/2 activity. Inhibiting ERK1/2 through overexpression of the regulatory protein PEA15 negates the resistance, revealing a key role for ERK1/2 in BCAR1/BCAR3-induced antiestrogen resistance. Reverse-phase protein array data show that PEA15 levels in invasive breast cancers correlate with patient survival, suggesting that PEA15 can override ERK1/2 activation by BCAR1/BCAR3 and other upstream regulators. We further uncovered that the BCAR3-related NSP3 can also promote antiestrogen resistance. Thus, strategies to disrupt BCAR1-BCAR3/NSP3 complexes and associated signaling networks could ultimately lead to new breast cancer therapies.

Dayem Ullah AZ, Cutts RJ, Ghetia M, et al.
The pancreatic expression database: recent extensions and updates.
Nucleic Acids Res. 2014; 42(Database issue):D944-9 [PubMed] Free Access to Full Article Related Publications
The Pancreatic Expression Database (PED, is the only device currently available for mining of pancreatic cancer literature data. It brings together the largest collection of multidimensional pancreatic data from the literature including genomic, proteomic, microRNA, methylomic and transcriptomic profiles. PED allows the user to ask specific questions on the observed levels of deregulation among a broad range of specimen/experimental types including healthy/patient tissue and body fluid specimens, cell lines and murine models as well as related treatments/drugs data. Here we provide an update to PED, which has been previously featured in the Database issue of this journal. Briefly, PED data content has been substantially increased and expanded to cover methylomics studies. We introduced an extensive controlled vocabulary that records specific details on the samples and added data from large-scale meta-analysis studies. The web interface has been improved/redesigned with a quick search option to rapidly extract information about a gene/protein of interest and an upload option allowing users to add their own data to PED. We added a user guide and implemented integrated graphical tools to overlay and visualize retrieved information. Interoperability with biomart-compatible data sets was significantly improved to allow integrative queries with pancreatic cancer data.

Lou S, Liu G, Shimada H, et al.
The lost intrinsic fragmentation of MAT1 protein during granulopoiesis promotes the growth and metastasis of leukemic myeloblasts.
Stem Cells. 2013; 31(9):1942-53 [PubMed] Free Access to Full Article Related Publications
MAT1, an assembly factor and targeting subunit of both cyclin-dependent kinase-activating kinase (CAK) and general transcription factor IIH (TFIIH) kinase, regulates cell cycle and transcription. Previous studies show that expression of intact MAT1 protein is associated with expansion of human hematopoietic stem cells (HSC), whereas intrinsically programmed or retinoic acid (RA)-induced MAT1 fragmentation accompanies granulocytic differentiation of HSC or leukemic myeloblasts. Here we determined that, in humanized mouse microenvironment, MAT1 overexpression resisted intrinsic MAT1 fragmentation to sustain hematopoietic CD34+ cell expansion while preventing granulopoiesis. Conversely, we mimicked MAT1 fragmentation in vitro and in a mouse model by overexpressing a fragmented 81-aa MAT1 polypeptide (pM9) that retains the domain for assembling CAK but cannot affix CAK to TFIIH-core. Our results showed that pM9 formed ΔCAK by competing with MAT1 for CAK assembly to mimic MAT1 fragmentation-depletion of CAK. This resulting ΔCAK acted as a dominant negative to inhibit the growth and metastasis of different leukemic myeloblasts, with or without RA resistance, by concurrently suppressing CAK and TFIIH kinase activities to inhibit cell cycle and gene transcription. These findings suggest that the intrinsically programmed MAT1 expression and fragmentation regulate granulopoiesis by inversely coordinating CAK and TFIIH activities, whereas pM9 shares a mechanistic resemblance with MAT1 fragmentation in suppressing myeloid leukemogenesis.

Wei C, Chen J, Pande M, et al.
A pilot study comparing protein expression in different segments of the normal colon and rectum and in normal colon versus adenoma in patients with Lynch syndrome.
J Cancer Res Clin Oncol. 2013; 139(7):1241-50 [PubMed] Free Access to Full Article Related Publications
PURPOSE: Lynch syndrome (LS) is a common inherited predisposition to colorectal cancer (CRC). In LS patients, CRC is predominantly located in the right colon, as opposed to sporadic CRC, which usually affects the left colon or rectum. Previous studies have demonstrated a clear distinction in gene expression between sporadic CRC and normal colon at different locations in the colorectum. However, little is known about LS gene expression profiles in different areas of the colorectum. Here, we compared the protein expression profiles for normal colorectal samples among different locations as well as between adenomas and matched normal tissue in LS.
METHODS: Protein from 33 tissue samples (27 normal tissues and 6 adenomas) from 9 patients with LS was extracted for reverse-phase protein array (RPPA) analysis. The antibody panel used for RPPA included 109 key proteins involved in various cancer-related pathways. Cluster 3.0 was used for unsupervised and supervised clustering analysis.
RESULTS: IGF1R and COL6A1 were expressed significantly differently between the normal right and normal left colon (q < 0.05); FN1, COL6A1, and IGF1R were expressed significantly differently between the normal right colon and normal rectum (q < 0.05). In the adenomas and matched normal tissue, PEA-15 was the only protein with significantly different expression (q < 0.05).
CONCLUSION: We found differences in protein expression between normal tissues from the right colon, left colon, and rectum as well as between adenomas and matched normal tissue. However, those differences should be further confirmed in a larger sample size.

Xie X, Bartholomeusz C, Ahmed AA, et al.
Bisphosphorylated PEA-15 sensitizes ovarian cancer cells to paclitaxel by impairing the microtubule-destabilizing effect of SCLIP.
Mol Cancer Ther. 2013; 12(6):1099-111 [PubMed] Free Access to Full Article Related Publications
Paclitaxel is a standard chemotherapeutic agent for ovarian cancer. PEA-15 (phosphoprotein enriched in astrocytes-15 kDa) regulates cell proliferation, autophagy, apoptosis, and glucose metabolism and also mediates AKT-dependent chemoresistance in breast cancer. The functions of PEA-15 are tightly regulated by its phosphorylation status at Ser104 and Ser116. However, the effect of PEA-15 phosphorylation status on chemosensitivity of cancer cells remains unknown. Here, we tested the hypothesis that PEA-15 phosphorylated at both Ser104 and Ser116 (pPEA-15) sensitizes ovarian cancer cells to paclitaxel. We first found that knockdown of PEA-15 in PEA-15-high expressing HEY and OVTOKO ovarian cancer cells resulted in paclitaxel resistance, whereas re-expression of PEA-15 in these cells led to paclitaxel sensitization. We next found that SKOV3.ip1-DD cells (expressing phosphomimetic PEA-15) were more sensitive to paclitaxel than SKOV3.ip1-AA cells (expressing nonphosphorylatable PEA-15). Compared with SKOV3.ip1-vector and SKOV3.ip1-AA cells, SKOV3.ip1-DD cells displayed reduced cell viability, inhibited anchorage-independent growth, and augmented apoptosis when treated with paclitaxel. Furthermore, HEY and OVTOKO cells displayed enhanced paclitaxel sensitivity when transiently overexpressing phosphomimetic PEA-15 and reduced paclitaxel sensitivity when transiently overexpressing nonphosphorylatable PEA-15. These results indicate that pPEA-15 sensitizes ovarian cancer cells to paclitaxel. cDNA microarray analysis suggested that SCLIP (SCG10-like protein), a microtubule-destabilizing protein, is involved in pPEA-15-mediated chemosensitization. We found that reduced expression and possibly posttranslational modification of SCLIP following paclitaxel treatment impaired the microtubule-destabilizing effect of SCLIP, thereby promoting induction of mitotic arrest and apoptosis by paclitaxel. Our findings highlight the importance of pPEA-15 as a promising target for improving the efficacy of paclitaxel-based therapy in ovarian cancer.

Romano G, Acunzo M, Garofalo M, et al.
MiR-494 is regulated by ERK1/2 and modulates TRAIL-induced apoptosis in non-small-cell lung cancer through BIM down-regulation.
Proc Natl Acad Sci U S A. 2012; 109(41):16570-5 [PubMed] Free Access to Full Article Related Publications
MicroRNAs (miRNAs) have an important role in the development of chemosensitivity or chemoresistance in different types of cancer. Activation of the ERK1/2 pathway is a major determinant of diverse cellular processes and cancer development and is responsible for the transcription of several important miRNAs. Here we show a link between the ERK1/2 pathway and BIM expression through miR-494. We blocked ERK1/2 nuclear activity through the overexpression of an ERK1/2 natural interactor, the protein PED/PEA15, and we performed a microRNA expression profile. miR-494 was the most down-regulated microRNA after ERK1/2 inactivation. Moreover, we found that miR-494 induced Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) resistance in non-small-cell lung cancer (NSCLC) through the down-modulation of BIM. Elucidation of this undiscovered ERK1/2 pathway that regulates apoptosis and cell proliferation through miR-494 in NSCLC will greatly enhance our understanding of the mechanisms responsible for TRAIL resistance and will provide an additional arm for the development of anticancer therapies.

Bartholomeusz C, Gonzalez-Angulo AM, Liu P, et al.
High ERK protein expression levels correlate with shorter survival in triple-negative breast cancer patients.
Oncologist. 2012; 17(6):766-74 [PubMed] Free Access to Full Article Related Publications
The mitogen-activated protein kinase (MAPK) signaling pathway is known to be activated in triple-negative breast cancer (TNBC). Extracellular signal-related kinase (ERK), a member of the MAPK pathway, promotes cell proliferation, angiogenesis, cell differentiation, and cell survival. To assess the prognostic impact of ERK in TNBC patients, relative quantities of ERK (ERK-2 and pMAPK) and direct targets of the ERK pathway (MAPK/ERK kinase 1, phospho-enriched protein in astrocytes [PEA]-15, phosphorylated (p)PEA-15, tuberous sclerosis protein 2, p70S6 kinase, and p27) were measured using reverse-phase protein arrays in tumor tissue from patients with TNBC (n = 97) and non-TNBC (n = 223). Protein levels in patients with TNBC were correlated with clinical and tumor characteristics and outcome. The median age of patients with TNBC was 55 years (range, 27-86 years). Disease stage was I in 21%, II in 60%, and III in 20% of the patients. In a multivariate analysis, among patients with TNBC, those with ERK-2-overexpressing tumors had a lower overall survival rate than those with low ERK-2-expressing tumors (hazard ratio [HR], 2.76; 95% confidence interval [CI], 1.19-6.41). However, high pMAPK levels were associated with a significantly higher relapse-free survival rate (HR, 0.66; 95% CI, 0.46-0.95). In conclusion, ERK-2 and pMAPK are valuable prognostic markers in TNBC. Further studies are justified to elucidate ERK's role in TNBC tumorigenicity and metastasis.

Gawecka JE, Geerts D, Koster J, et al.
PEA15 impairs cell migration and correlates with clinical features predicting good prognosis in neuroblastoma.
Int J Cancer. 2012; 131(7):1556-68 [PubMed] Free Access to Full Article Related Publications
ERK and RSK2 drive proliferation and invasion of many cancers. Phosphoprotein enriched in astrocytes 15 (PEA15) binds ERK and RSK2 and high PEA15 levels can impair ERK- and RSK2-dependent transcription. PEA15 expression also inversely correlates with cell motility and invasiveness. We therefore tested PEA15 effects on neuroblastoma cells in vitro. We further analyzed PEA15 expression in the context of clinical and genetic features of neuroblastoma in tumor samples to determine its correlation with disease progression. Affymetrix microarray analysis was performed using 24 different neuroblastoma cell lines. Cell lines expressing low to intermediate levels of PEA15 were chosen for in vitro functional studies. The cell line results were verified by Affymetrix analysis of three different neuroblastic tumor types (total of 110 samples) PEA15 overexpression inhibited neuroblastoma migration in vitro. We verified that inhibition of motility required PEA15 interaction with its binding partners ERK and RSK2. Additionally, synthetic inhibitors of RSK2 suppressed integrin-dependent migration. PEA15 expression correlates with clinical parameters and a 25% increase in patient survival rate. The highest PEA15 levels were found in low stage, more differentiated and less metastatic neuroblastic tumors, and correlated with lack of MYCN amplification. PEA15 blocks neuroblastoma migration through inhibition of ERK/RSK2 signaling. PEA15 expression levels correlate with favorable clinical features suggesting that PEA15 limits metastatic progression of neuroblastoma. Thus, PEA15 and its partners ERK and RSK2 are potential targets for the development of new therapeutics to impede progression of minimal residual disease in patients with high-risk neuroblastoma.

Sulzmaier FJ, Valmiki MK, Nelson DA, et al.
PEA-15 potentiates H-Ras-mediated epithelial cell transformation through phospholipase D.
Oncogene. 2012; 31(30):3547-60 [PubMed] Free Access to Full Article Related Publications
The small GTPase H-Ras is a proto-oncogene that activates a variety of different pathways including the extracellular-signal-regulated kinase (ERK)/mitogen-activated protein kinase pathway. H-Ras is mutated in many human malignancies, and these mutations cause the protein to be constitutively active. Phosphoprotein enriched in astrocytes, 15 kDa (PEA-15) blocks ERK-dependent gene transcription and inhibits proliferation by sequestering ERK in the cytoplasm. We therefore investigated whether PEA-15 influences H-Ras-mediated transformation. We found that PEA-15 does not block H-Ras-activated proliferation when H-Ras is constitutively active. We show instead that in H-Ras-transformed mouse kidney epithelial cells, co-expression of PEA-15 resulted in enhanced soft agar colony growth and increased tumor growth in vivo. Overexpression of both H-Ras and PEA-15 resulted in accelerated G1/S cell cycle transition and increased activation of the ERK signaling pathway. PEA-15 mediated these effects through activation of its binding partner phospholipase D1 (PLD1). Inhibition of PLD1 or interference with PEA-15/PLD1 binding blocked PEA-15's ability to increase ERK activation. Our findings reveal a novel mechanism by which PEA-15 positively regulates Ras/ERK signaling and increases the proliferation of H-Ras-transformed epithelial cells through enhanced PLD1 expression and activation. Thus, our work provides a surprising mechanism by which PEA-15 augments H-Ras-driven transformation. These data reveal that PEA-15 not only suppresses ERK signaling and tumorigenesis but also alternatively enhances tumorigenesis in the context of active Ras.

Formisano P, Ragno P, Pesapane A, et al.
PED/PEA-15 interacts with the 67 kD laminin receptor and regulates cell adhesion, migration, proliferation and apoptosis.
J Cell Mol Med. 2012; 16(7):1435-46 [PubMed] Free Access to Full Article Related Publications
Phosphoprotein enriched in diabetes/phosphoprotein enriched in astrocytes-15 kD (PED/PEA-15) is an anti-apoptotic protein whose expression is increased in several human cancers. In addition to apoptosis, PED/PEA-15 is involved in the regulation of other major cellular functions, including cell adhesion, migration, proliferation and glucose metabolism. To further understand the functions of this protein, we performed a yeast two-hybrid screening using PED/PEA-15 as a bait and identified the 67 kD high-affinity laminin receptor (67LR) as an interacting partner. 67 kD laminin receptor is a non-integrin cell-surface receptor for the extracellular matrix (ECM), derived from the dimerization of a 37 kD cytosolic precursor (37LRP). The 67LR is highly expressed in human cancers and widely recognized as a molecular marker of metastatic aggressiveness. The molecular interaction of PED/PEA-15 with 67LR was confirmed by pull-down experiments with recombinant His-tagged 37LRP on lysates of PED/PEA-15 transfected HEK-293 cells. Further, overexpressed or endogenous PED/PEA-15 was co-immunoprecipitated with 67LR in PED/PEA-15-transfected HEK-293 cells and in U-373 glioblastoma cells, respectively. PED/PEA-15 overexpression significantly increased 67LR-mediated HEK-293 cell adhesion and migration to laminin that, in turn, determined PED/PEA-15 phosphorylation both in Ser-104 and Ser-116, thus enabling cell proliferation and resistance to apoptosis. PED/PEA-15 ability to induce cell responses to ECM-derived signals through interaction with 67LR may be of crucial importance for tumour cell survival in a poor microenvironment, thus favouring the metastatic spread and colonization.

Cutts RJ, Gadaleta E, Lemoine NR, Chelala C
Using BioMart as a framework to manage and query pancreatic cancer data.
Database (Oxford). 2011; 2011:bar024 [PubMed] Free Access to Full Article Related Publications
We describe the Pancreatic Expression Database (PED), the first cancer database originally designed based on the BioMart infrastructure. The PED portal brings together multidimensional pancreatic cancer data from the literature including genomic, proteomic, miRNA and gene expression profiles. Based on the BioMart 0.7 framework, the database is easily integrated with other BioMart-compliant resources, such as Ensembl and Reactome, to give access to a wide range of annotations alongside detailed experimental conditions. This article is intended to give an overview of PED, describe its data content and work through examples of how to successfully mine and integrate pancreatic cancer data sets and other BioMart resources.

Wang F, Bhat K, Doucette M, et al.
Docosahexaenoic acid (DHA) sensitizes brain tumor cells to etoposide-induced apoptosis.
Curr Mol Med. 2011; 11(6):503-11 [PubMed] Free Access to Full Article Related Publications
In this study, we investigated whether DHA, a nutritionally important n-3 unsaturated fatty acid, modulated the sensitivity of brain tumor cells to the anticancer drug, etoposide (VP16). Medulloblastoma (MB) cell lines, Daoy and D283, and glioblastoma (GBM) cell lines, U138 and U87, were exposed to DHA or VP16 alone or in combination. The effects on cell proliferation and the induction of apoptosis were determined by using MTS and Hoechest 33342/PI double staining. U87 and U138 cells were found to be insensitive to the addition of DHA and VP16, whereas the two MB cell lines showed high sensitivity. DHA or VP16 alone showed little effect on cell proliferation or death in either the MB or GBM cell lines, but pretreatment with DHA enhanced the responsiveness to VP16 in the MB cell lines. To understand the mechanisms of combined DHA and VP16 on MB cells, pathway specific oligo array analyses were performed to dissect possible signaling pathways involved. The addition of DHA and VP16, in comparison to VP16 added alone, resulted in marked suppression in the expression of several genes involved in DNA damage repair, cell proliferation, survival, invasion, and angiogenesis, including PRKDC, Survivin, PIK3R1, MAPK14, NFκB1, NFκBIA, BCL2, CD44, and MAT1. These results suggest (1) that the effects of DHA and VP16 in brain tumor cells are mediated in part by the down regulation of events involved in DNA repair and the PI3K/MAPK signaling pathways and (2) that brain tumors genotypically mimicked by MB cells may benefit from therapies combining DHA with VP16.

Fuss JO, Tainer JA
XPB and XPD helicases in TFIIH orchestrate DNA duplex opening and damage verification to coordinate repair with transcription and cell cycle via CAK kinase.
DNA Repair (Amst). 2011; 10(7):697-713 [PubMed] Free Access to Full Article Related Publications
Helicases must unwind DNA at the right place and time to maintain genomic integrity or gene expression. Biologically critical XPB and XPD helicases are key members of the human TFIIH complex; they anchor CAK kinase (cyclinH, MAT1, CDK7) to TFIIH and open DNA for transcription and for repair of duplex distorting damage by nucleotide excision repair (NER). NER is initiated by arrested RNA polymerase or damage recognition by XPC-RAD23B with or without DDB1/DDB2. XP helicases, named for their role in the extreme sun-mediated skin cancer predisposition xeroderma pigmentosum (XP), are then recruited to asymmetrically unwind dsDNA flanking the damage. XPB and XPD genetic defects can also cause premature aging with profound neurological defects without increased cancers: Cockayne syndrome (CS) and trichothiodystrophy (TTD). XP helicase patient phenotypes cannot be predicted from the mutation position along the linear gene sequence and adjacent mutations can cause different diseases. Here we consider the structural biology of DNA damage recognition by XPC-RAD23B, DDB1/DDB2, RNAPII, and ATL, and of helix unwinding by the XPB and XPD helicases plus the bacterial repair helicases UvrB and UvrD in complex with DNA. We then propose unified models for TFIIH assembly and roles in NER. Collective crystal structures with NMR and electron microscopy results reveal functional motifs, domains, and architectural elements that contribute to biological activities: damaged DNA binding, translocation, unwinding, and ATP driven changes plus TFIIH assembly and signaling. Coupled with mapping of patient mutations, these combined structural analyses provide a framework for integrating and unifying the rich biochemical and cellular information that has accumulated over forty years of study. This integration resolves puzzles regarding XP helicase functions and suggests that XP helicase positions and activities within TFIIH detect and verify damage, select the damaged strand for incision, and coordinate repair with transcription and cell cycle through CAK signaling.

Cho SJ, Kim YJ, Surh YJ, et al.
Ibulocydine is a novel prodrug Cdk inhibitor that effectively induces apoptosis in hepatocellular carcinoma cells.
J Biol Chem. 2011; 286(22):19662-71 [PubMed] Free Access to Full Article Related Publications
Hepatocellular carcinoma (HCC) is frequently associated with abnormalities in cell cycle regulation, leading to increased activity of cyclin-dependent kinases (Cdks) due to the loss, or low expression of, Cdk inhibitors. In this study, we showed that ibulocydine (an isobutyrate prodrug of the specific Cdk inhibitor, BMK-Y101) is a candidate anti-cancer drug for HCC. Ibulocydine has high activity against Cdk7/cyclin H/Mat1 and Cdk9/cyclin T. Ibulocydine inhibited the growth of HCC cells more effectively than other Cdk inhibitors, including olomoucine and roscovitine, whereas ibulocydine as well as the other Cdk inhibitors and BMK-Y101 minimally influenced the growth of normal hepatocyte cells. Ibulocydine induced apoptosis in HCC cells, most likely by inhibiting Cdk7 and Cdk9. In vitro treatment of HCC cells with ibulocydine rapidly blocked phosphorylation of the carboxyl-terminal domain (CTD) of the large subunit of RNA polymerase II, a process mediated by Cdk7/9. Anti-apoptotic gene products such as Mcl-1, survivin, and X-linked IAP (XIAP) are crucial for the survival of many cell types, including HCC. Following the inhibition of RNA polymerase II phosphorylation, ibulocydine caused rapid down-regulation of Mcl-1, survivin, and XIAP, thus inducing apoptosis. Furthermore, ibulocydine effectively induced apoptosis in HCC xenografts with no toxic side effects. These results suggest that ibulocydine is a strong candidate anti-cancer drug for the treatment of HCC.

Tan BK, Chen J, Adya R, Randeva HS
Phosphoprotein enriched in diabetes gene product (Ped/pea-15) is increased in omental adipose tissue of women with the polycystic ovary syndrome: ex vivo regulation of ped/pea-15 by glucose, insulin and metformin.
Diabetes Obes Metab. 2011; 13(2):181-4 [PubMed] Related Publications
Polycystic ovary syndrome (PCOS), the commonest endocrine disorder in women, is characterized by an altered steroid milieu and is associated with insulin resistance and type 2 diabetes mellitus (T2DM). Phosphoprotein enriched in diabetes gene product (Ped/pea-15) regulates glucose metabolism and is increased in T2DM. Our novel data indicate that Ped/pea-15 mRNA expression and protein levels are significantly increased in omental adipose tissue (AT) from PCOS women compared to matched controls (p < 0.01); Ped/pea-15 levels in subcutaneous AT were not significantly different. Furthermore, Ped/pea-15 mRNA expression and protein levels were higher in omental compared to subcutaneous AT in PCOS subjects (p < 0.01); however, in control subjects, this was not significant. Glucose was predictive of omental AT Ped/pea-15 mRNA expression (p = 0.045). Importantly, glucose and insulin increased whereas metformin significantly decreased Ped/pea-15 levels in human omental AT explants. Our findings should serve to promote further research on Ped/pea-15 biology.

Cutts RJ, Gadaleta E, Hahn SA, et al.
The Pancreatic Expression database: 2011 update.
Nucleic Acids Res. 2011; 39(Database issue):D1023-8 [PubMed] Free Access to Full Article Related Publications
The Pancreatic Expression database (PED, has established itself as the main repository for pancreatic-derived -omics data. For the past 3 years, its data content and access have increased substantially. Here we describe several of its new and improved features, such as data content, which now includes over 60,000 measurements derived from transcriptomics, proteomics, genomics and miRNA profiles from various pancreas-centred reports on a broad range of specimen and experimental types. We also illustrate the capabilities of its interface, which allows integrative queries that can combine PED data with a growing number of biological resources such as NCBI, Ensembl, UniProt and Reactome. Thus, PED is capable of retrieving and integrating different types of -omics, annotations and clinical data. We also focus on the importance of data sharing and interoperability in the cancer field, and the integration of PED into the International Cancer Genome Consortium (ICGC) data portal.

Böck BC, Tagscherer KE, Fassl A, et al.
The PEA-15 protein regulates autophagy via activation of JNK.
J Biol Chem. 2010; 285(28):21644-54 [PubMed] Free Access to Full Article Related Publications
PEA-15/PED (phosphoprotein enriched in astrocytes 15 kDa/phosphoprotein enriched in diabetes) is a death effector domain-containing protein which is known to modulate apoptotic cell death. The mechanism by which PEA-15 inhibits caspase activation and increases ERK (extracellular-regulated kinase) activity is well characterized. Here, we demonstrate that PEA-15 is not only pivotal in the activation of the ERK pathway but also modulates JNK (c-Jun N-terminal kinase) signaling. Upon overexpression of PEA-15 in malignant glioma cells, JNK is potently activated. The PEA-15-induced JNK activation depends on the phosphorylation of PEA-15 at both phosphorylation sites (serine 104 and serine 116). The activation of JNK is substantially inhibited by siRNA-mediated down-regulation of endogenous PEA-15. Moreover, we demonstrate that glioma cells overexpressing PEA-15 show increased signs of autophagy in response to classical autophagic stimuli such as ionizing irradiation, serum deprivation, or rapamycin treatment. In contrast, the non-phosphorylatable mutants of PEA-15 are not capable of promoting autophagy. The inhibition of JNK abrogates the PEA-15-mediated increase in autophagy. In conclusion, our data show that PEA-15 promotes autophagy in glioma cells in a JNK-dependent manner. This might render glioma cells more resistant to adverse stimuli such as starvation or ionizing irradiation.

Botta G, Perruolo G, Libertini S, et al.
PED/PEA-15 modulates coxsackievirus-adenovirus receptor expression and adenoviral infectivity via ERK-mediated signals in glioma cells.
Hum Gene Ther. 2010; 21(9):1067-76 [PubMed] Related Publications
Glioblastoma multiforme (GBM) is the most aggressive human brain tumor, and is highly resistant to chemo- and radiotherapy. Selectively replicating oncolytic viruses represent a novel approach for the treatment of neoplastic diseases. Coxsackievirus-adenovirus receptor (CAR) is the primary receptor for adenoviruses, and loss or reduction of CAR greatly decreases adenoviral entry. Understanding the mechanisms regulating CAR expression and localization will contribute to increase the efficacy of oncolytic adenoviruses. Two glioma cell lines (U343MG and U373MG) were infected with the oncolytic adenovirus dl922-947. U373MG cells were more susceptible to cell death after viral infection, compared with U343MG cells. The enhanced sensitivity was paralleled by increased adenoviral entry and CAR mRNA and protein levels in U373MG cells. In addition, U373MG cells displayed a decreased ERK1/2 (extracellular signal-regulated kinase-1/2) nuclear-to-cytosolic ratio, compared with U343MG cells. Intracellular content of PED/PEA-15, an ERK1/2-interacting protein, was also augmented in these cells. Both ERK2 overexpression and genetic silencing of PED/PEA-15 by antisense oligonucleotides increased ERK nuclear accumulation and reduced CAR expression and adenoviral entry. Our data indicate that dl922-947 could represent an useful tool for the treatment of GBM and that PED/PEA-15 modulates CAR expression and adenoviral entry, by sequestering ERK1/2.

Incoronato M, Garofalo M, Urso L, et al.
miR-212 increases tumor necrosis factor-related apoptosis-inducing ligand sensitivity in non-small cell lung cancer by targeting the antiapoptotic protein PED.
Cancer Res. 2010; 70(9):3638-46 [PubMed] Related Publications
PED/PEA-15 (PED) is a death effector domain family member of 15 kDa with a broad antiapoptotic function found overexpressed in a number of different human tumors, including lung cancer. To date, the mechanisms that regulate PED expression are unknown. Therefore, we address this point by the identification of microRNAs that in non-small cell lung cancer (NSCLC) modulate PED levels. In this work, we identify miR-212 as a negative regulator of PED expression. We also show that ectopic expression of this miR increases tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced cell death in NSCLC cells. In contrast, inhibition of endogenous miR-212 by use of antago-miR results in increase of PED protein expression and resistance to TRAIL treatment. Besides, in NSCLC, we show both in vitro and in vivo that PED and miR-212 expressions are inversely correlated, that is, PED is upregulated and miR-212 is rarely expressed. In conclusion, these findings suggest that miR-212 should be considered as a tumor suppressor because it negatively regulates the antiapoptotic protein PED and regulates TRAIL sensitivity.

May T, Virtanen C, Sharma M, et al.
Low malignant potential tumors with micropapillary features are molecularly similar to low-grade serous carcinoma of the ovary.
Gynecol Oncol. 2010; 117(1):9-17 [PubMed] Related Publications
OBJECTIVE: Low-grade serous carcinoma (LGSC) is a chemoresistant ovarian neoplasm thought to potentially arise in a background of low malignant potential tumors (LMP), which are typically non-aggressive. However, LMP with micropapillary features (LMP-MP) have more aggressive clinical behavior and may represent an intermediate in progression to LGSC. The objective of this study was to obtain and compare gene expression profiles of LMP, LMP-MP and LGSC to determine if LMP-MP more closely resembles LGSC, and to identify genes involved in LGSC carcinogenesis.
METHODS: Epithelial cells from LMP (n=17), LMP-MP (n=9) and LGSC (n=11) were isolated by laser capture microdissection. RNA was extracted, reverse transcribed to cDNA, amplified and hybridized to Affymetrix U133 Plus2 genechip arrays. Gene expression data were checked for quality, filtered and significantly altered genes between subgroups were identified. Differential expression of selected genes was verified by RT-qPCR and immunohistochemistry.
RESULTS: Gene expression analysis identified differential expression between LMP and LMP-MP, LMP and LGSC but not LMP-MP and LGSC. Integration of differentially expressed genes into the protein interaction database CytoScape highlighted gene products in the MAPK pathway as differentially regulated between LMP and LGSC. Four genes were selected and validated by RT-qPCR performed on microarray samples (n=15) and immunohistochemistry on a representative microarray (n=57).
CONCLUSION: The gene expression profile of LMP-MP is similar to LGSC and distinct from LMP, reflecting their more aggressive clinical behavior. Candidate genes in the MAPK pathway were highlighted which may play a role in LGSC carcinogenesis and indicate potential therapeutic targets.

Majumdar S, Friedrich CA, Koch CA, et al.
Compound heterozygous mutation with a novel splice donor region DNA sequence variant in the succinate dehydrogenase subunit B gene in malignant paraganglioma.
Pediatr Blood Cancer. 2010; 54(3):473-5 [PubMed] Related Publications
Pheochromocytoma and paraganglioma (PGL) are rare neuroendocrine tumors in children. Apparently sporadic cases of PGL may harbor germline mutations in the succinate dehydrogenase (SDHx) gene. SDHB mutations are associated with malignant disease. We report a 13-year-old African American boy with diffusely metastatic PGL and compound heterozygous mutation leading to a novel splice donor region DNA sequence variant in the SDHB gene. Family history was positive for non-classical congenital adrenal hyperplasia and pituitary adenoma. After surgical resection of the primary PGL and chemotherapy, he was treated with metaiodobenzy lguanidine (MIBG) combined with arsenic trioxide. At 3-year follow-up, he had stable disease.

Peirce SK, Findley HW
High level MycN expression in non-MYCN amplified neuroblastoma is induced by the combination treatment nutlin-3 and doxorubicin and enhances chemosensitivity.
Oncol Rep. 2009; 22(6):1443-9 [PubMed] Related Publications
MYCN gene amplification is a negative prognostic indicator in neuroblastoma and high level MycN expression in Stage IV neuroblastoma is generally a hallmark of poor patient outcome. However, high level expression of the MycN protein in neuroblastoma cells lacking MYCN amplification suppresses growth and drives apoptosis; this, in part, explains the absence of clinical observations of high level MycN in neuroblastoma lacking MYCN amplification. In the current study, we found that combination treatment with nutlin-3 and doxorubicin upregulated MycN expression in non-MYCN-amplified neuroblastoma cells at both the protein and mRNA levels. The induced expression of MycN in non-MYCN-amplified cells inhibited cell proliferation and increased apoptosis. MycN induction also upregulated p53, p21 and Bax protein levels, as well as mRNA levels for the positive neuroblastoma prognostic factors CD44 and EFNB3. Blocking MycN reversed these effects. These results were corroborated by findings using a MycN-inducible system in SHEP cells, another MYCN non-amplified neuroblastoma cell line. Our results indicate that doxorubicin/nutlin-3 combination treatment both induces expression of MycN in a non-MYCN-amplified background and sensitizes neuroblastoma cells to chemotherapy. These findings support the idea that induction of MycN in non-MYCN-amplified cells drives neuroblastoma cells toward apoptosis and suggest that combination nutlin-3/doxorubicin treatment may be clinically important.

Kuramitsu Y, Miyamoto H, Tanaka T, et al.
Proteomic differential display analysis identified upregulated astrocytic phosphoprotein PEA-15 in human malignant pleural mesothelioma cell lines.
Proteomics. 2009; 9(22):5078-89 [PubMed] Related Publications
We performed proteomic differential display analysis of human malignant pleural mesothelioma (MPM) cell lines and a human pleural mesothelial cell line by using 2-DE and LC-MS/MS. The human MPM cell lines were NCI-H28, NCI-H2052 and NCI-H2452, and the human pleural mesothelial cell line was MeT-5A. Between MeT-5A and NCI-H2052, we found 38 protein spots whose expression levels were different, from the results of 2-DE; 28 protein spots appeared higher, and 10 other protein spots lower in NCI-H2052 than in MeT-5A. These spots were analyzed by LC-MS/MS analysis and identified by a peptide sequence tag. However, from the results of 2-DE of the other cell lines, there was only one consistently upregulated protein, astrocytic phosphoprotein PEA-15, in all three MPM cell lines. Western blotting using specific antibodies against PEA-15 confirmed the elevated expression level of PEA-15 in all three MPM cell lines compared with MeT-5A cells and normal pleura tissues from patients. PEA-15 was knocked down in NCI-H2052 cells, and the proliferation of PEA-15-silenced NCI-H2052 cells was suppressed 7-15% compared with negative control cells. These results suggest that PEA-15 expression is likely to be associated with the tumorigenesis of MPM.

Mourtada-Maarabouni M, Williams GT
Protein phosphatase 4 regulates apoptosis in leukemic and primary human T-cells.
Leuk Res. 2009; 33(11):1539-51 [PubMed] Free Access to Full Article Related Publications
The control of T-cell survival is of overwhelming importance for preventing leukemia and lymphoma. The present report demonstrates that the serine/threonine protein phosphatase PP4 regulates the survival of both leukemic T-cells and untransformed human peripheral blood T-cells, particularly after treatment with anti-leukemic drugs and other cytotoxic stimuli. PP4-induced apoptosis is mediated, at least in part, through de-phosphorylation of apoptosis regulator PEA-15, previously implicated in the control of leukemic cell survival. PP4 activity significantly affects the mutation rate in leukemic T-cells, indicating that PP4 dysfunction may be important in the development and progression of leukemia.

Bellail AC, Tse MC, Song JH, et al.
DR5-mediated DISC controls caspase-8 cleavage and initiation of apoptosis in human glioblastomas.
J Cell Mol Med. 2010; 14(6A):1303-17 [PubMed] Free Access to Full Article Related Publications
To explore the molecular mechanisms by which glioblastomas are resistant to tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), we examined TRAIL signalling pathways in the tumours. TRAIL has four membrane-anchored receptors, death receptor 4/5 (DR4/5) and decoy receptor 1/2 (DcR1/2). Of these receptors, only DR5 was expressed consistently in glioblastoma cell lines and tumour tissues, ruling out the role of DcR1/2 in TRAIL resistance. Upon TRAIL binding, DR5 was homotrimerized and recruited Fas-associated death domain (FADD) and caspase-8 for the assembly of death-inducing signalling complex (DISC) in the lipid rafts of the plasma membrane. In the DISC, caspase-8 was cleaved and initiated apoptosis by cleaving downstream caspases in TRAIL-sensitive glioblastoma cells. In TRAIL-resistant cells, however, DR5-mediated DISC was modified by receptor-interacting protein (RIP), cellular FADD-like interleukin-1beta-converting enzyme inhibitory protein (c-FLIP) and phosphoprotein enriched in diabetes or in astrocyte-15 (PED/PEA-15). This DISC modification occurred in the non-raft fractions of the plasma membrane and resulted in the inhibition of caspase-8 cleavage and activation of nuclear factor-kappaB (NF-kappaB). Treatment of resistant cells with parthenolide, an inhibitor of inhibitor of kappaB (I-kappaB), eliminated TRAIL-induced NF-kappaB activity but not TRAIL resistance. In contrast, however, targeting of RIP, c-FLIP or PED/PEA-15 with small interfering RNA (siRNA) led to the redistribution of the DISC from non-rafts to lipid rafts and eliminated the inhibition of caspase-8 cleavage and thereby TRAIL resistance. Taken together, this study indicates that the DISC modification by RIP, c-FLIP and PED/PEA-15 is the most upstream event in TRAIL resistance in glioblastomas.

Peirce SK, Findley HW
The MDM2 antagonist nutlin-3 sensitizes p53-null neuroblastoma cells to doxorubicin via E2F1 and TAp73.
Int J Oncol. 2009; 34(5):1395-402 [PubMed] Related Publications
Neuroblastoma (NB) is a primitive neuroectodermal tumor and the second most common solid tumor in children. NB exhibits heterogeneous behavior and spontaneous regression can occur in patients under 12 months of age. Response to treatment is both age- and stage-specific; however, patients over 1 year of age are generally considered high risk. NB tumors from these patients are often characterized by alterations in p53 expression and murine double minute (MDM2) activity with concomitant resistance to chemotherapy. We evaluated the ability of nutlin-3 to sensitize a p53-null and doxorubicin-resistant NB cell line, LA155N, to doxorubicin. Nutlin-3 treatment upregulated TAp73 and E2F1 protein levels. It potentiated the ability of doxorubicin to block cell proliferation and activate apoptosis and TAp73 knockdown resulted in a reduction of this sensitization. Additionally, PUMA expression was induced by the combination treatment, but reduced by knockdown of either TAp73 or E2F1. We conclude that, following nutlin-3 treatment, TAp73 and E2F1 are released from MDM2 and activated by doxorubicin to induce PUMA and apoptosis. This study addresses p53-independent mechanisms of nutlin-3 action in chemoresistant NB, especially in combination with chemotherapeutics. We believe that this model has strong clinical relevance for chemoresistant and p53 dysfunctional NB.

Tomizawa D, Koh K, Hirayama M, et al.
Outcome of recurrent or refractory acute lymphoblastic leukemia in infants with MLL gene rearrangements: A report from the Japan Infant Leukemia Study Group.
Pediatr Blood Cancer. 2009; 52(7):808-13 [PubMed] Related Publications
BACKGROUND: Despite the poor outcome of recurrent or refractory acute lymphoblastic leukemia (ALL) in infants with MLL gene rearrangement, few studies have focused on this specific group. We conducted a retrospective analysis of infants with recurrent or refractory ALL from two previous consecutive Japanese studies to clarify the characteristics and prognostic factors among these patients
PROCEDURE: All recurrent or refractory ALL infants with MLL gene rearrangement (MLL-R) who were registered in two consecutive Japanese nation-wide multicentric trials (MLL96 and MLL98; between 1995 and 2001) were eligible for the study.
RESULTS: Among 80 MLL-R ALL infants, 34 cases of recurrence and 5 induction failures occurred. The median duration of first remission was 5 months (range, 0-28 months). All patients underwent various salvage chemotherapies; remission was achieved in 40.5% (15/37). A total of 23 patients received subsequent hematopoietic stem cell transplantations (HSCT): 9 in remission, 12 without remission, and 2 with unknown status. With median follow-up period of 5.5 years, the 5-year overall survival (OS) rate after the second-line treatment was 25.6% +/- 6.9%. Young age (<3 months) and central nervous system involvement at initial diagnosis were associated with poor outcome; however, failure to achieve remission after salvage therapy was the sole independent poor prognostic factor in multivariate analysis (P = 0.01).
CONCLUSIONS: The prognosis of infants with recurrent or refractory MLL-R ALL is extremely poor despite alternative treatments including HSCT; therefore, it is necessary to develop novel treatment strategies.

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