JAG1

Gene Summary

Gene:JAG1; jagged 1
Aliases: AGS, AHD, AWS, HJ1, CD339, JAGL1
Location:20p12.1-p11.23
Summary:The jagged 1 protein encoded by JAG1 is the human homolog of the Drosophilia jagged protein. Human jagged 1 is the ligand for the receptor notch 1, the latter a human homolog of the Drosophilia jagged receptor notch. Mutations that alter the jagged 1 protein cause Alagille syndrome. Jagged 1 signalling through notch 1 has also been shown to play a role in hematopoiesis. [provided by RefSeq, Jul 2008]
Databases:OMIM, VEGA, HGNC, Ensembl, GeneCard, Gene
Protein:protein jagged-1
HPRD
Source:NCBIAccessed: 20 August, 2015

Ontology:

What does this gene/protein do?
Show (43)
Pathways:What pathways are this gene/protein implicaed in?
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Cancer Overview

Research Indicators

Publications Per Year (1990-2015)
Graph generated 20 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.

  • Neoplasm Invasiveness
  • Gene Expression
  • Vascular Endothelial Growth Factor Receptor-2
  • Gene Expression Profiling
  • Immunoenzyme Techniques
  • Young Adult
  • Chromosome 20
  • Cell Movement
  • Apoptosis
  • Transcription
  • Intercellular Signaling Peptides and Proteins
  • Western Blotting
  • Acute Myeloid Leukaemia
  • NOTCH1 Receptor
  • Messenger RNA
  • Liver Cancer
  • Basic Helix-Loop-Helix Transcription Factors
  • Neoplastic Cell Transformation
  • Down-Regulation
  • MicroRNAs
  • Biological Models
  • Trans-Activators
  • Cell Proliferation
  • Cell Differentiation
  • Promoter Regions
  • Calcium-Binding Proteins
  • Membrane Proteins
  • Brain Tumours
  • RNA-Binding Proteins
  • Up-Regulation
  • Staging
  • Signal Transduction
  • Leukemic Gene Expression Regulation
  • Wnt Proteins
  • Notch Receptors
  • Repressor Proteins
  • Oligonucleotide Array Sequence Analysis
  • Breast Cancer
  • Cancer Gene Expression Regulation
  • Hepatocellular Carcinoma
Tag cloud generated 20 August, 2015 using data from PubMed, MeSH and CancerIndex

Specific Cancers (4)

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: JAG1 (cancer-related)

Kim JA, Shim JS, Lee GY, et al.
Microenvironmental remodeling as a parameter and prognostic factor of heterogeneous leukemogenesis in acute myelogenous leukemia.
Cancer Res. 2015; 75(11):2222-31 [PubMed] Related Publications
Acute myelogenous leukemia (AML) is a heterogeneous disorder characterized by clonal proliferation of stem cell-like blasts in bone marrow (BM); however, their unique cellular interaction within the BM microenvironment and its functional significance remain unclear. Here, we assessed the BM microenvironment of AML patients and demonstrate that the leukemia stem cells induce a change in the transcriptional programming of the normal mesenchymal stromal cells (MSC). The modified leukemic niche alters the expressions of cross-talk molecules (i.e., CXCL12 and JAG1) in MSCs to provide a distinct cross-talk between normal and leukemia cells, selectively suppressing normal primitive hematopoietic cells while supporting leukemogenesis and chemoresistance. Of note, AML patients exhibited distinct heterogeneity in the alteration of mesenchymal stroma in BM. The distinct pattern of stromal changes in leukemic BM at initial diagnosis was associated with a heterogeneous posttreatment clinical course with respect to the maintenance of complete remission for 5 to 8 years and early or late relapse. Thus, remodeling of mesenchymal niche by leukemia cells is an intrinsic self-reinforcing process of leukemogenesis that can be a parameter for the heterogeneity in the clinical course of leukemia and hence serve as a potential prognostic factor.

Jeong HJ, Koo BS, Kang TH, et al.
Inhibitory effects of Saururus chinensis and its components on stomach cancer cells.
Phytomedicine. 2015; 22(2):256-61 [PubMed] Related Publications
Saururus chinensis (SC) Baill. (Saururaceae), a perennial herb commonly called Chinese lizard's tail or Sam-baekcho in Korea, has been used in the treatment of edema, gonorrhea, jaundice, and inflammatory diseases. Recently, several reports have been commissioned to examine the anti-cancer activities of this plant. In this study, we evaluated the inhibitory activity and mechanism of action on SC and its components against stomach cancer cells. SC extracts displayed cytotoxic effects on AGS cells in a dose-dependent manner. Moreover, SC increased the number of annexin V-positive apoptotic bodies and phosphorylated JNK and p38 in AGS cells. SC also down-regulated anti-apoptotic (Bcl-2) genes and up-regulated apoptotic (Bax) genes in AGS cells. We further confirmed that caspase activation plays an important role in SC-induced apoptosis in AGS cells. Furthermore, we examined erythro-Austrobailignan-6 and meso-dihydroguaiaretic acid, major active constituents of SC, which induced apoptosis in both the AGS and NCI-N87 stomach cancer cell lines. Taken together, our data provide the evidence that SC and its components induce apoptosis in stomach cancer cells, making it a potential candidate as a chemotherapeutic drug.

Suarez G, Romero-Gallo J, Piazuelo MB, et al.
Modification of Helicobacter pylori Peptidoglycan Enhances NOD1 Activation and Promotes Cancer of the Stomach.
Cancer Res. 2015; 75(8):1749-59 [PubMed] Article available free on PMC after 15/04/2016 Related Publications
Helicobacter pylori (H. pylori) is the strongest known risk factor for gastric carcinogenesis. One cancer-linked locus is the cag pathogenicity island, which translocates components of peptidoglycan into host cells. NOD1 is an intracellular immune receptor that senses peptidoglycan from Gram-negative bacteria and responds by inducing autophagy and activating NF-κB, leading to inflammation-mediated bacterial clearance; however chronic pathogens can evade NOD1-mediated clearance by altering peptidoglycan structure. We previously demonstrated that the H. pylori cag(+) strain 7.13 rapidly induces gastric cancer in Mongolian gerbils. Using 2D-DIGE and mass spectrometry, we identified a novel mutation within the gene encoding the peptidoglycan deacetylase PgdA; therefore, we sought to define the role of H. pylori PgdA in NOD1-dependent activation of NF-κB, inflammation, and cancer. Coculture of H. pylori strain 7.13 or its pgdA(-) isogenic mutant with AGS gastric epithelial cells or HEK293 epithelial cells expressing a NF-κB reporter revealed that pgdA inactivation significantly decreased NOD1-dependent NF-κB activation and autophagy. Infection of Mongolian gerbils with an H. pylori pgdA(-) mutant strain led to significantly decreased levels of inflammation and malignant lesions in the stomach; however, preactivation of NOD1 before bacterial challenge reciprocally suppressed inflammation and cancer in response to wild-type H. pylori. Expression of NOD1 differs in human gastric cancer specimens compared with noncancer samples harvested from the same patients. These results indicate that peptidoglycan deacetylation plays an important role in modulating host inflammatory responses to H. pylori, allowing the bacteria to persist and induce carcinogenic consequences in the gastric niche.

Zanetti M
Tapping CD4 T cells for cancer immunotherapy: the choice of personalized genomics.
J Immunol. 2015; 194(5):2049-56 [PubMed] Related Publications
Cellular immune responses that protect against tumors typically have been attributed to CD8 T cells. However, CD4 T cells also play a central role. It was shown recently that, in a patient with metastatic cholangiocarcinoma, CD4 T cells specific for a peptide from a mutated region of ERBB2IP could arrest tumor progression. This and other recent findings highlight new opportunities for CD4 T cells in cancer immunotherapy. In this article, I discuss the role and regulation of CD4 T cells in response to tumor Ags. Emphasis is placed on the types of Ags and mechanisms that elicit tumor-protective responses. I discuss the advantages and drawbacks of cancer immunotherapy through personalized genomics. These considerations should help to guide the design of next-generation therapeutic cancer vaccines.

Nisimova L, Wen S, Cross-Knorr S, et al.
Role of Raf kinase inhibitor protein in Helicobacter pylori-mediated signaling in gastric cancer.
Crit Rev Oncog. 2014; 19(6):469-81 [PubMed] Related Publications
Helicobacter pylori is a helical bacterium that colonizes the stomach in over half of the world's population. Infection with this bacterium has been linked to peptic ulcer disease and gastric cancer. The bacterium has been shown to affect regulatory pathways in its host cells through specific virulence factors that control gene expression. Infection with H. pylori increases levels of phosphorylation of Raf kinase inhibitor protein (pRKIP) in gastric adenocarcinoma (AGS) cells in vitro and in vivo. We investigated the role of H. pylori in the phosphorylation of RKIP as a possible mechanism to downregulate pro-survival signals in gastric adenocarcinoma. pRKIP induces RKIP transcriptional activity, which serves to induce apoptosis of damaged cells to prevent further tumorigenesis. Infection of wild type and RKIP knockout mice with H. pylori for 2 months further confirmed roles of RKIP and pRKIP in the prevention of gastric cancer progression. Loss of RKIP in AGS cells results in increased expression of the Cag A virulence factor after H. pylori infection and RKIP overexpression inhibits H. pylori-mediated STAT3 phosphorylation and STAT3 and NF-κB transcriptional activity. We examined the role of mTOR (mammalian target of rapamycin) after H. pylori infection on the phosphorylation of RKIP. Cells treated with rapamycin, an inhibitor of mTOR, displayed less expression of pRKIP after H. pylori infection. Microarray antibody analysis was conducted on wild-type and RKIP-knockdown AGS cells and showed that in the absence of RKIP, there was increased expression of pro-tumorigenic proteins such as EGFR, Raf-1, and MAPKs. Although further work is needed to confirm the interaction of RKIP and mTOR in AGS cells as a result of H. pylori infection, we hypothesize that H. pylori-mediated induction of pro-survival signaling in gastric epithelial cells induces a feedback response through the activation of RKIP. The phosphorylated, or active, form of RKIP is important in protecting gastric epithelial cells from tumorigenesis after H. pylori infection.

God JM, Cameron C, Figueroa J, et al.
Elevation of c-MYC disrupts HLA class II-mediated immune recognition of human B cell tumors.
J Immunol. 2015; 194(4):1434-45 [PubMed] Article available free on PMC after 15/02/2016 Related Publications
Elevated levels of the transcription factor c-myc are strongly associated with various cancers, and in particular B cell lymphomas. Although many of c-MYC's functions have been elucidated, its effect on the presentation of Ag through the HLA class II pathway has not been reported previously. This is an issue of considerable importance, given the low immunogenicity of many c-MYC-positive tumors. We report in this paper that increased c-MYC expression has a negative effect on the ability of B cell lymphomas to functionally present Ags/peptides to CD4(+) T cells. This defect was associated with alterations in the expression of distinct cofactors as well as interactions of antigenic peptides with class II molecules required for the presentation of class II-peptide complexes and T cell engagement. Using early passage Burkitt's lymphoma (BL) tumors and transformed cells, we show that compared with B lymphoblasts, BL cells express decreased levels of the class II editor HLA-DM, lysosomal thiol-reductase GILT, and a 47-kDa enolase-like protein. Functional Ag presentation was partially restored in BL cells treated with a c-MYC inhibitor, demonstrating the impact of this oncogene on Ag recognition. This restoration of HLA class II-mediated Ag presentation in early passage BL tumors/cells was linked to enhanced HLA-DM expression and a concurrent decrease in HLA-DO in BL cells. Taken together, these results reveal c-MYC exerts suppressive effects at several critical checkpoints in Ag presentation, which contribute to the immunoevasive properties of BL tumors.

Akrami H, Aminzadeh S, Fallahi H
Inhibitory effect of ibuprofen on tumor survival and angiogenesis in gastric cancer cell.
Tumour Biol. 2015; 36(5):3237-43 [PubMed] Related Publications
Numerous epidemiological studies have suggested effectiveness of long-term and regular use of non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and aspirin, in preventing and treatment of certain cancers including prostate, colon, breast, lung, and gastric cancers. We have studied the potential anti-turmeric effect of ibuprofen in adenocarcinoma gastric cell line (AGS). The effects of ibuprofen were investigated on cell proliferation, apoptosis, angiogenesis, and expression of stemness marker genes using real-time RT-PCR, DNA laddering, and tube formation assays via ECM gel and human umbilical vein endothelial cells (HUVECs). Annexin-V-FLUOS and propidium iodide (PI) were used to stain the apoptotic cells. Our findings indicate that ibuprofen at the concentrations of 100, 200, 300, 400, and 500 μM is able to reduce the cancerous characteristics of the AGS cells by inducing apoptosis, inhibition of cell proliferation, and angiogenesis. Real-time RT-PCR showed that ibuprofen altered the expression of several genes including Akt, P53, PCNA, Bax, and Bcl2 in the AGS cells. In addition, reduction in CD44 and OCT3/4 transcript levels revealed that ibuprofen reduces the stemness of the AGS cells and therefore it could be used as a potential anti-tumor drug.

Zhang LN, Yan YB
Depletion of poly(A)-specific ribonuclease (PARN) inhibits proliferation of human gastric cancer cells by blocking cell cycle progression.
Biochim Biophys Acta. 2015; 1853(2):522-34 [PubMed] Related Publications
Regulation of mRNA decay plays a crucial role in the post-transcriptional control of cell growth, survival, differentiation, death and senescence. Deadenylation is a rate-limiting step in the silence and degradation of the bulk of highly regulated mRNAs. However, the physiological functions of various deadenylases have not been fully deciphered. In this research, we found that poly(A)-specific ribonuclease (PARN) was upregulated in gastric tumor tissues and gastric cancer cell lines MKN28 and AGS. The cellular function of PARN was investigated by stably knocking down the endogenous PARN in the MKN28 and AGS cells. Our results showed that PARN-depletion significantly inhibited the proliferation of the two types of gastric cancer cells and promoted cell death, but did not significantly affect cell motility and invasion. The depletion of PARN arrested the gastric cancer cells at the G0/G1 phase by upregulating the expression levels of p53 and p21 but not p27. The mRNA stability of p53 was unaffected by PARN-knockdown in both types of cells. A significant stabilizing effect of PARN-depletion on p21 mRNA was observed in the AGS cells but not in the MKN28 cells. We further showed that the p21 3'-UTR triggered the action of PARN in the AGS cells. The dissimilar observations between the MKN28 and AGS cells as well as various stress conditions suggested that the action of PARN strongly relied on protein expression profiles of the cells, which led to heterogeneity in the stability of PARN-targeted mRNAs.

Ahn J, Barber GN
Self-DNA, STING-dependent signaling and the origins of autoinflammatory disease.
Curr Opin Immunol. 2014; 31:121-6 [PubMed] Related Publications
Self-DNA has long been considered a key cause of inflammatory and autoimmune disease, although the exact origin and general mechanisms of action have remained to be elucidated. Recently, new insight has been gained into our understanding of those innate immune pathways and sensors that are responsible for instigating self-DNA triggered autoinflammatory events in the cell. One such sensor referred to as STING (for stimulator of interferon genes) has been found to be seminal for controlling cytosolic-DNA induced cytokine production, and may be responsible for a wide variety of inflammatory diseases including systemic lupus erythematosus (SLE), Aicardi-Goutieres syndrome (AGS) and STING-associated vasculopathy with onset of infancy (SAVI). STING may also be involved with augmenting certain types of carcinogen induced cancer. Aside from generating valuable information into mechanisms underlining innate immune gene regulation, these findings offer new opportunities to generate innovative therapeutics which may help treat such diseases.

Kim H, Choi H, Lee SK
Epstein-Barr virus miR-BART20-5p regulates cell proliferation and apoptosis by targeting BAD.
Cancer Lett. 2015; 356(2 Pt B):733-42 [PubMed] Related Publications
Although Epstein-Barr virus (EBV) BamHI A rightward transcript (BART) microRNAs (miRNAs) are ubiquitously expressed in EBV-associated tumors, the role of most BART miRNAs is unclear. In this study, we showed that Bcl-2-associated death promoter (BAD) expression was significantly lower in EBV-infected AGS-EBV cells than in EBV-negative AGS cells and investigated whether BART miRNAs target BAD. Using bioinformatics analysis, five BART miRNAs showing seed match with the 3' untranslated region (3'-UTR) of BAD were selected. Of these, only miR-BART20-5p reduced BAD expression when individually transfected into AGS cells. A luciferase assay revealed that miR-BART20-5p directly targets BAD. The expression of BAD mRNA and protein was decreased by miR-BART20-5p and increased by an inhibitor of miR-BART20-5p. PE-Annexin V staining and cell proliferation assays showed that miR-BART20-5p reduced apoptosis and enhanced cell growth. Furthermore, miR-BART20-5p increased chemoresistance to 5-fluorouracil and docetaxel. Our data suggest that miR-BART20-5p contributes to tumorigenesis of EBV-associated gastric carcinoma by directly targeting the 3'-UTR of BAD.

Liao A, Wang W, Sun D, et al.
Bone morphogenetic protein 2 mediates epithelial-mesenchymal transition via AKT and ERK signaling pathways in gastric cancer.
Tumour Biol. 2015; 36(4):2773-8 [PubMed] Related Publications
Although deregulation of bone morphogenetic protein 2 (BMP2) signaling has been linked to various types of cancers, the relationships between abnormal activation of these signaling pathways and tumorigenesis are not clear in gastric cancer. We hypothesized that BMP2 might be involved in epithelial-mesenchymal transition (EMT) process of gastric cancer. Here, BMPR-II activation and inhibition in gastric cancer cell line AGS were induced with exogenous BMP2 and with BMPR-II small interfering RNA (siRNA), respectively. BMPR-II downstream signal molecules AKT, ERK phosphorylation, and EMT biomarkers (vimentin, snail, N-cadherin, and E-cadherin) were tested using the Western blot. In the present study, our results showed that BMP2 can induce AKT and ERK phosphorylation in a dose-dependent method, and endogenous BMPR-II can be inhibited completely by BMPR-II siRNA in AGS. Notably BMP2 alone treatment can induce the up-regulation of vimentin, snail, and N-cadherin in AGS cells, besides, the down-regulation of E-cadherin also occurred. On the contrary, BMPR-II siRNA significantly prohibited BMP2-induced AKT and ERK phosphorylation, at the same time, EMT biomarkers changes were not observed. On the other hand, BMPR-II knockdown could significantly affect AGS wound closure and the migration ability (p < 0.001) compared to control siRNA and BMP2 alone. In conclusion, this study suggested that EMT process can be triggered by the BMP2/BMPR axis in gastric cancer and then involved in the tumor cell migration, invasion, and metastasis via the activation of PI3K/AKT and MEK/ERK pathways. Our study lays a new foundation for the treatment of gastric cancer through antagonizing BMP2 system.

Chaudhry MS, Karadimitris A
Role and regulation of CD1d in normal and pathological B cells.
J Immunol. 2014; 193(10):4761-8 [PubMed] Article available free on PMC after 15/02/2016 Related Publications
CD1d is a nonpolymorphic, MHC class I-like molecule that presents phospholipid and glycosphingolipid Ags to a subset of CD1d-restricted T cells called invariant NKT (iNKT) cells. This CD1d-iNKT cell axis regulates nearly all aspects of both the innate and adaptive immune responses. Expression of CD1d on B cells is suggestive of the ability of these cells to present Ag to, and form cognate interactions with, iNKT cells. In this article, we summarize key evidence regarding the role and regulation of CD1d in normal B cells and in humoral immunity. We then extend the discussion to B cell disorders, with emphasis on autoimmune disease, viral infection, and neoplastic transformation of B lineage cells, in which CD1d expression can be altered as a mechanism of immune evasion and can have both diagnostic and prognostic importance. Finally, we highlight current and future therapeutic strategies that aim to target the CD1d-iNKT cell axis in B cells.

Yue Z, Feng W, Xiangke L, et al.
WAVE3 promotes epithelial-mesenchymal transition of gastric cancer through upregulation of Snail.
Cancer Gene Ther. 2014; 21(12):499-506 [PubMed] Related Publications
WAVE3, an actin cytoskeleton remodeling protein overexpressed in many kinds of cancers, has been associated with a lot of metastatic diseases. However, the role and mechanisms of the high expression of WAVE3 in human gastric cancer has not been fully elucidated. Here we demonstrated that WAVE3 was expressed in all six kinds of gastric-cancer cell lines: BGC-823, SGC-7901, AGS, MGC803, MKN28 and MKN45. Furthermore, a correlation was found between aggressiveness of these cell lines and expression of WAVE3. Next, we investigated the role of WAVE3 in SGC-7901 cells and found that upregulating WAVE3 could promote the migration, invasion and proliferation of SGC-7901 cells in vitro. It has been reported that WAVE3 could induce cancer invasion and metastasis by participating epithelial-mesenchymal transition (EMT). However, the mechanisms are not entirely clear. In this study we showed that elevated WAVE3 levels could induce EMT in SGC-7901 cells by dampening the expression of E-cadherin while increasing the expression of vimentin. Elevated WAVE3 levels could also improve the expression of transcription factor Snail. In addition, downregulating Snail could particularly reduce EMT and the metastasis, invasion and proliferation activity in SGC-7901 cells elevated by overexpression of WAVE3. Taken together, we demonstrated that WAVE3 promoted gastric-cancer-cells migration and invasion by taking part in EMT via upregulation of Snail. WAVE3 could be a useful target for gastric-cancer prevention and therapy.

Zhu X, Liu J, Xu X, et al.
The Pleckstrin and Sec7 domain-containing gene as a novel epigenetic modification marker in human gastric cancer and its clinical significance.
Int J Oncol. 2015; 46(1):195-204 [PubMed] Related Publications
The Pleckstrin and Sec7 domain-containing (PSD) gene has been recently found to participate in the progression of several types of cancer. In the present study, we identified PSD as a candidate tumor suppressor gene silenced through epigenetic modification in gastric cancer (GC). PSD mRNA expression and DNA methylation were evaluated by real-time reverse-transcriptase polymerase chain reaction (RT-PCR) and methylation-specific PCR in GC cell lines and tissue samples. Involvement of histone modification in GC cell lines was examined by chromatin immunoprecipitation assay. We also used an siRNA-mediated approach to knock down the PSD gene in SGC7901 cells, which was utilized to detect the role of PSD in GC progression, followed by analysis of cell apoptosis and invasion. PSD gene expression was reduced in all GC cell lines compared with GES1 (an immortalized normal gastric cell line). In addition, PSD expression was markedly downregulated in gastric carcinoma tissues when compared to adjacent non-tumor tissues. Our data also indicated that PSD mRNA and protein levels were associated with tumor differentiation and lymph node metastasis. Aberrant DNA methylation status and histone modification were also found in GC cell lines. Enhanced gene expression was detected when the HGC27, AGS and BGC823 GC cell lines were treated with the DNA-demethylating agent 5-aza-2'-deoxycytidine. However, treatment with trichostatin A, a histone deacetylase inhibitor, had no effect on PSD expression in any of the GC cell lines. Suppression of PSD by siRNA led to enhanced SGC7901 cell invasion. The depletion of PSD expression inhibited cell proliferation and decreased apoptosis in SGC7901 cell lines. Knockdown of the PSD expression decreased caspase-3 and -7 protein levels in SGC7901 cells. PSD gene may function as a tumor suppressor in GC suggesting a vital role for DNA methylation and histone modification in PSD silencing. PSD expression might be a useful biomarker for epigenetic-based GC early diagnosis and may lead to the identification of new targets for pharmacological intervention.

Zhang B, Guo X, Zhang J, et al.
MicroRNA‑224 is downregulated in mucinous cystic neoplasms of the pancreas and may regulate tumorigenesis by targeting Jagged1.
Mol Med Rep. 2014; 10(6):3303-9 [PubMed] Related Publications
The underlying malignancy of mucinous cystic neoplasms (MCNs) of the pancreas most commonly results in patients undergoing surgery. The tumorigenesis of MCNs remains elusive and few studies have investigated the role of specific micro (mi)RNAs in MCNs. The present study focused on the expression of miRNA‑224 and its putative target gene Jagged1 (Jag1) to examine its role in tumorigenesis and its suitability as a biomarker for MCNs. Paired tissue samples confirmed by surgical pathology were used to screen the miRNAs involved in MCNs with miRNA microarrays (n=3), and to verify the differentially expressed miRNAs (n=3) and mRNAs of candidate target genes of miRNAs by quantitative polymerase chain reaction (qPCR; n=8). Immunohistochemistry was conducted to confirm the expression and location of Jag1 in the neoplastic epithelial cells. Luciferase assays were performed to confirm the direct target gene of miRNA‑224. miRNA microarray analysis revealed that two differentially expressed miRNAs were closely associated with tumorigenesis and pancreatic diseases. The qPCR results revealed that miRNA‑224 was more significantly aberrantly expressed and the mRNA expression levels of its putative target gene, Jag1, were upregulated. Strong, diffuse cytoplasmic immunohistochemical labeling of Jag1 with occasional nuclear labeling was detected in the mucinous epithelium. Luciferase reporter activity was significantly reduced by co‑transfected miRNA‑224 mimics and pMIR‑Jag1‑wild-type, which suggested that miRNA‑224 bound to recognition sites in the 3' untranslated region of its target mRNA, Jag1. In conclusion, miRNA‑224 was downregulated in MCNs and may regulate tumorigenesis by targeting Jag1. Further studies investigating the role of miRNAs and functional analysis of epigenetic alterations are required to examine the diagnostic and therapeutic potential of miRNAs in MCNs.

Hoppes R, Oostvogels R, Luimstra JJ, et al.
Altered peptide ligands revisited: vaccine design through chemically modified HLA-A2-restricted T cell epitopes.
J Immunol. 2014; 193(10):4803-13 [PubMed] Article available free on PMC after 15/02/2016 Related Publications
Virus or tumor Ag-derived peptides that are displayed by MHC class I molecules are attractive starting points for vaccine development because they induce strong protective and therapeutic cytotoxic T cell responses. In thus study, we show that the MHC binding and consequent T cell reactivity against several HLA-A*02 restricted epitopes can be further improved through the incorporation of nonproteogenic amino acids at primary and secondary anchor positions. We screened more than 90 nonproteogenic, synthetic amino acids through a range of epitopes and tested more than 3000 chemically enhanced altered peptide ligands (CPLs) for binding affinity to HLA-A*0201. With this approach, we designed CPLs of viral epitopes, of melanoma-associated Ags, and of the minor histocompatibility Ag UTA2-1, which is currently being evaluated for its antileukemic activity in clinical dendritic cell vaccination trials. The crystal structure of one of the CPLs in complex with HLA-A*0201 revealed the molecular interactions likely responsible for improved binding. The best CPLs displayed enhanced affinity for MHC, increasing MHC stability and prolonging recognition by Ag-specific T cells and, most importantly, they induced accelerated expansion of antitumor T cell frequencies in vitro and in vivo as compared with the native epitope. Eventually, we were able to construct a toolbox of preferred nonproteogenic residues with which practically any given HLA-A*02 restricted epitope can be readily optimized. These CPLs could improve the therapeutic outcome of vaccination strategies or can be used for ex vivo enrichment and faster expansion of Ag-specific T cells for transfer into patients.

Yuan TM, Liang RY, Hsiao NW, Chuang SM
The S100A4 D10V polymorphism is related to cell migration ability but not drug resistance in gastric cancer cells.
Oncol Rep. 2014; 32(6):2307-18 [PubMed] Article available free on PMC after 15/02/2016 Related Publications
Upregulation of the metastasis-promoting S100A4 protein has been linked to tumor migration and invasion, and clinical studies have demonstrated that significant expression of S100A4 in primary tumors is indicative of poor prognosis. However, the involvement of S100A4 in the drug responsiveness of gastric cancer remains unclear. In the present study, we used gastric cancer cell lines as a model to investigate the involvement of S100A4 in drug responsiveness. We overexpressed S100A4 in AGS and SCM-1 cells, which are characterized by relatively low-level expression of endogenous S100A4, and found that this significantly enhanced cell migration but did not affect cell survival in the presence of six common anticancer drugs. Moreover, in vitro cell proliferation was unchanged. Using RNA interference, we suppressed S100A4 expression in MKN-45 and TMK-1 cells (which are characterized by high-level expression of endogenous S100A4), and found that knockdown of S100A4 markedly attenuated cell motility but did not affect cell survival in the presence of six common anticancer drugs. Further study revealed that a single nucleotide polymorphism (SNP) of S100A4 (rs1803245; c.29A>T), which substitutes an Asp residue with Val (D10V), is localized within the conserved binding surface for Annexin II. Cells overexpressing S100A4D10V showed a significant reduction in cell migration ability, but no change in cell survival, upon anticancer drug treatment. Taken together, our novel results indicate that the expression level of S100A4 does not significantly affect cell survival following anticancer drug treatment. Thus, depending on the cell context, the metastasis-promoting effects of S100A4 may not be positively correlated with anticancer drug resistance in the clinic.

Chen B, Chen X, Wu X, et al.
Disruption of microRNA-21 by TALEN leads to diminished cell transformation and increased expression of cell-environment interaction genes.
Cancer Lett. 2015; 356(2 Pt B):506-16 [PubMed] Related Publications
MicroRNA-21 is dysregulated in many cancers and fibrotic diseases. Since miR-21 suppresses several tumor suppressor and anti-apoptotic genes, it is considered a cancer therapeutic target. Antisense oligonucleotides are commonly used to inhibit a miRNA; however, blocking miRNA function via an antagomir is temporary, often only achieves a partial knock-down, and may be complicated by off-target effects. Here, we used transcription activator-like effector nucleases (TALENs) to disrupt miR-21 in cancerous cells. Individual deletion clones were screened and isolated without drug selection. Sequencing and quantitative RT-PCR identified clones with no miR-21 expression. The loss of miR-21 led to subtle but global increases of mRNAs containing miR-21 target sequences. Cells without miR-21 became more sensitive to cisplatin and less transformed in culture and in mouse xenografts. In addition to the increase of PDCD4 and PTEN protein, mRNAs for COL4A1, JAG1, SERPINB5/Maspin, SMAD7, and TGFBI - all are miR-21 targets and involved in TGFβ and fibrosis regulation - were significantly upregulated in miR-21 knockout cells. Gene ontology and pathway analysis suggested that cell-environment interactions involving extracellular matrix can be an important miR-21 pathogenic mechanism. The study also demonstrates the value of using TALEN-mediated microRNA gene disruption in human pathobiological studies.

Zhang L, Wu Z, Ma Z, et al.
WWP1 as a potential tumor oncogene regulates PTEN-Akt signaling pathway in human gastric carcinoma.
Tumour Biol. 2015; 36(2):787-98 [PubMed] Related Publications
Whelming evidence has demonstrated that WW domain containing E3 ubiquitin protein ligase 1 (WWP1) participates in a wide variety of biological processes and is tightly related to the initiation and progression of many tumors. Currently, although mounting evidence supports a role of WWP1 in tumor promotion and tumorigenesis, the potential roles of WWP1 and its biological functions in gastric carcinoma are not fully understood. Here, we found that WWP1 messenger RNA (mRNA) and protein were highly expressed in gastric carcinoma tissues and cells. High WWP1 mRNA and protein levels were tightly related to differentiation status, TNM stage, invasive depth, lymph node metastasis, and poor prognosis in gastric carcinoma. Furthermore, WWP1 siRNA significantly decreased WWP1 protein level in MKN-45 and AGS cells; meanwhile, WWP1 depletion markedly inhibited tumor proliferation in vitro and in vivo, arrested cell cycle at G0/G1 phase, and induced cell apoptosis in MKN-45 and AGS cells. Most notably, WWP1 downregulation both inactivated PTEN-Akt signaling pathway in MKN-45 and AGS cells. Taken altogether, our findings suggest that WWP1 acts as an oncogenic factor and should be considered as a novel interfering molecular target for gastric carcinoma.

Shi LS, Wang H, Wang F, et al.
Effects of gastrokine‑2 expression on gastric cancer cell apoptosis by activation of extrinsic apoptotic pathways.
Mol Med Rep. 2014; 10(6):2898-904 [PubMed] Article available free on PMC after 15/02/2016 Related Publications
Gastrokine‑2 is a putative gastric cancer‑specific tumor suppressor gene, the loss of which is known to be involved in the development and progression of gastric cancer, and restoration of gastrokine‑2 expression inhibits growth of gastric cancer cells in vitro. However, the underlying mechanism of these effects requires elucidation. In the present study, expression patterns of gastrokine‑2 protein were examined in gastric cancer tissues and cell lines. Expression of gastrokine‑2 was restored in gastric cancer cells in order to assess its effect on cell viability, apoptosis and gene expression. A total of 76 gastric cancer tissues with corresponding normal mucosae samples, and two gastric cancer cell lines (SGC‑7901 and AGS) were subjected to western blot analysis of gastrokine‑2 expression. SGC‑7901 cells were transiently transfected with gastrokine‑2 cDNA and then treated with anti‑CD95 and/or anti‑Fas antibodies prior to analysis of cell viability, apoptosis and gene expression levels. Expression of gastrokine‑2 protein was reduced or absent in gastric cancer tissues and gastric cancer cell lines. Following restoration of gastrokine‑2 expression, the protein expression level of Fas was significantly increased, but no marked change was observed in the levels of bcl‑2 and Bax proteins. Expression of gastrokine‑2 protein reduced gastric cancer cell viability and induced apoptosis. Activity of caspase‑3 and caspase‑8 was increased, but caspase‑9 activity remained unchanged in the SGC‑7901 cells. Reduction or knockout of gastrokine‑2 protein expression may contribute to gastric cancer development or progression, as the current study demonstrated that restoration of gastrokine‑2 expression induces apoptosis of gastric cancer cells through the extrinsic apoptosis pathway.

Wolff AS, Kärner J, Owe JF, et al.
Clinical and serologic parallels to APS-I in patients with thymomas and autoantigen transcripts in their tumors.
J Immunol. 2014; 193(8):3880-90 [PubMed] Article available free on PMC after 15/02/2016 Related Publications
Patients with the autoimmune polyendocrine syndrome type I (APS-I), caused by mutations in the autoimmune regulator (AIRE) gene, and myasthenia gravis (MG) with thymoma, show intriguing but unexplained parallels. They include uncommon manifestations like autoimmune adrenal insufficiency (AI), hypoparathyroidism, and chronic mucocutaneous candidiasis plus autoantibodies neutralizing IL-17, IL-22, and type I IFNs. Thymopoiesis in the absence of AIRE is implicated in both syndromes. To test whether these parallels extend further, we screened 247 patients with MG, thymoma, or both for clinical features and organ-specific autoantibodies characteristic of APS-I patients, and we assayed 26 thymoma samples for transcripts for AIRE and 16 peripheral tissue-specific autoantigens (TSAgs) by quantitative PCR. We found APS-I-typical autoantibodies and clinical manifestations, including chronic mucocutaneous candidiasis, AI, and asplenia, respectively, in 49 of 121 (40%) and 10 of 121 (8%) thymoma patients, but clinical features seldom occurred together with the corresponding autoantibodies. Both were rare in other MG subgroups (n = 126). In 38 patients with APS-I, by contrast, we observed neither autoantibodies against muscle Ags nor any neuromuscular disorders. Whereas relative transcript levels for AIRE and 7 of 16 TSAgs showed the expected underexpression in thymomas, levels were increased for four of the five TSAgs most frequently targeted by these patients' autoantibodies. Therefore, the clinical and serologic parallels to APS-I in patients with thymomas are not explained purely by deficient TSAg transcription in these aberrant AIRE-deficient tumors. We therefore propose additional explanations for the unusual autoimmune biases they provoke. Thymoma patients should be monitored for potentially life-threatening APS-I manifestations such as AI and hypoparathyroidism.

Liu M, Inoue K, Leng T, et al.
TRPM7 channels regulate glioma stem cell through STAT3 and Notch signaling pathways.
Cell Signal. 2014; 26(12):2773-81 [PubMed] Article available free on PMC after 01/12/2015 Related Publications
Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor in adults with median survival time of 14.6 months. A small fraction of cancer stem cells (CSC) initiate and maintain tumors thus driving glioma tumorigenesis and being responsible for resistance to classical chemo- and radio-therapies. It is desirable to identify signaling pathways related to CSC to develop novel therapies to selectively target them. Transient receptor potential cation channel, subfamily M, member 7, also known as TRPM7 is a ubiquitous, Ca(2+) and Mg(2+) permeable ion channels that are special in being both an ion channel and a serine/threonine kinase. In studies of glioma cells silenced for TRPM7, we demonstrated that Notch (Notch1, JAG1, Hey2, and Survivin) and STAT3 pathways are down regulated in glioma cells grown in monolayer. Furthermore, phospho-STAT3, Notch target genes and CSC markers (ALDH1 and CD133) were significantly higher in spheroid glioma CSCs when compared with monolayer cultures. The results further show that tyrosine-phosphorylated STAT3 binds and activates the ALDH1 promoters in glioma cells. We found that TRMP7-induced upregulation of ALDH1 expression is associated with increases in ALDH1 activity and is detectable in stem-like cells when expanded as spheroid CSCs. Finally, TRPM7 promotes proliferation, migration and invasion of glioma cells. These demonstrate that TRPM7 activates JAK2/STAT3 and/or Notch signaling pathways and leads to increased cell proliferation and migration. These findings for the first time demonstrates that TRPM7 (1) activates a previously unrecognized STAT3→ALDH1 pathway, and (2) promotes the induction of ALDH1 activity in glioma cells.

Xue TC, Zou JH, Chen RX, et al.
Spatial localization of the JAG1/Notch1/osteopontin cascade modulates extrahepatic metastasis in hepatocellular carcinoma.
Int J Oncol. 2014; 45(5):1883-90 [PubMed] Related Publications
The model of Notch-driven carcinogenesis and development of hepatocellular carcinoma remains controversial and is based on observations of developmental stage- and dose-dependent Notch activation. In this study, the relevance of the spatial distribution of Notch cascade members to the promotion of hepatocellular carcinoma metastasis was evaluated. The spatial expression patterns of the members of the Jagged1 (JAG1)/Notch1 cascade in HCC were evaluated in a tissue microarray of 112 tumors and 46 peri-tumors. Regulation of JAG1/Notch1 on osteopontin (OPN) was evaluated by RNA interference. Tumor cells with JAG1 expressed on the membrane (JAG1(Mem)) were more likely to undergo extrahepatic metastasis [p<0.001; hazard ratio (HR), 0.166; 95% CI, 0.068-0.402], and JAG1(Mem) was a strong independent prognostic factor for metastasis (HR, 0.467; 95% CI, 0.271-0.806; p=0.006). JAG1(Mem) also showed a strong positive correlation with Notch1(Mem). In addition, tumors with JAG1(Mem) expression had more poorly encapsulated membranes (p=0.014). Furthermore, Notch1(Mem) expression correlated with HCC metastasis and was the strongest predictive factor for metastasis. However, in peri-tumoral tissues, most JAG1 (45/46) and Notch1 (41/46) was localized to the cytoplasm. The expression of OPN, one of the main targets of JAG1/Notch1 signaling and a crucial metastasis-related gene in HCC, correlated significantly with JAG1(Mem) expression. Knockdown of JAG1 expression or Notch1 expression induced the downregulation of OPN in HCC cells. Taken together, protein localization is a critical factor affecting the activity of the Notch cascade in the development of hepatocellular carcinoma. Furthermore, our results suggest that the JAG1/Notch1/OPN cascade represents a potential therapeutic target for hepatocellular carcinoma metastasis.

Liang Q, Yao X, Tang S, et al.
Integrative identification of Epstein-Barr virus-associated mutations and epigenetic alterations in gastric cancer.
Gastroenterology. 2014; 147(6):1350-62.e4 [PubMed] Related Publications
BACKGROUND & AIMS: The mechanisms by which Epstein-Barr virus (EBV) contributes to the development of gastric cancer are unclear. We investigated EBV-associated genomic and epigenomic variations in gastric cancer cells and tumors.
METHODS: We performed whole-genome, transcriptome, and epigenome sequence analyses of a gastric adenocarcinoma cell line (AGS cells), before and after EBV infection. We then looked for alterations in gastric tumor samples, with (n = 34) or without (n = 100) EBV infection, collected from patients at the Prince of Wales Hospital, Chinese University of Hong Kong (from 1998 through 2004), or the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China (from 1999 through 2006).
RESULTS: Transcriptome analysis showed that infected cells expressed 9 EBV genes previously detected in EBV-associated gastric tumors and 71 EBV genes not previously reported in gastric tumors. Ten viral genes that had not been reported previously in gastric cancer but were expressed most highly in EBV-infected cells also were expressed in primary EBV-positive gastric tumors. Whole-genome sequence analysis identified 45 EBV-associated nonsynonymous mutations. These mutations, in genes such as AKT2, CCNA1, MAP3K4, and TGFBR1, were associated significantly with EBV-positive gastric tumors, compared with EBV-negative tumors. An activating mutation in AKT2 was associated with reduced survival times of patients with EBV-positive gastric cancer (P = .006); this mutation was found to dysregulate mitogen-activated protein kinase signaling. Integrated epigenome and transcriptome analyses identified 216 genes transcriptionally down-regulated by EBV-associated hypermethylation; methylation of ACSS1, FAM3B, IHH, and TRABD increased significantly in EBV-positive tumors. Overexpression of Indian hedgehog (IHH) and TraB domain containing (TRABD) increased proliferation and colony formation of gastric cancer cells, whereas knockdown of these genes reduced these activities. We found 5 signaling pathways (axon guidance, focal adhesion formation, interactions among cytokines and receptors, mitogen-activated protein kinase signaling, and actin cytoskeleton regulation) to be affected commonly by EBV-associated genomic and epigenomic alterations.
CONCLUSIONS: By using genomic, transcriptome, and epigenomic comparisons of EBV infected vs noninfected gastric cancer cells and tumor samples, we identified alterations in genes, gene expression, and methylation that affect different signaling networks. These might be involved in EBV-associated gastric carcinogenesis.

Felipe AV, Moraes AA, de Oliveira J, et al.
Establishment and partial characterization of an epirubicin-resistant gastric cancer cell line with upregulated ABCB1.
Asian Pac J Cancer Prev. 2014; 15(16):6849-53 [PubMed] Related Publications
Multidrug resistance (MDR) is a major impediment to successful chemotherapy of gastric cancer. Our aim was to establish an epirubicin-resistant cell subline (AGS/EPI) and to elucidate the mechanisms involved in acquired EPI resistance. The AGS/EPI cell subline developed by exposing parental AGS cells to stepwise increasing concentrations of EPI demonstrated 2.52-fold resistance relative to the AGS cell line, and mRNA expression of the ATP-dependent drug-efflux pump P-glycoprotein (Pgp), more recently known as ABCB1 protein, was similarly upregulated. An AGS/EPI cell subline could thus be effectively established, and MDR mechanism of these cells was shown to be related to the overexpression of mRNA of the ABCB1 gene.

Chen F, Zhuang M, Peng J, et al.
Baicalein inhibits migration and invasion of gastric cancer cells through suppression of the TGF-β signaling pathway.
Mol Med Rep. 2014; 10(4):1999-2003 [PubMed] Related Publications
The transforming growth factor-β (TGF-β) signaling pathway exhibits an important role in cancer invasion and metastasis. Excessive expression of TGF-β activates Smad4, leading to the upregulation of downstream metastasis-associated genes. Thus, the inhibition of the TGF-β/Smad4 signaling pathway may be a novel strategy for treatment of cancer metastasis. Baicalein, a flavonoid derived from the root of Scutellaria baicalensis, has been reported to exert strong anti-tumor activity towards various types of cancer. In the present study the effect of baicalein on migration and invasion of cancer cells was evaluated using wound-healing and Transwell assays. In order to investigate the possible molecular mechanisms of the anti-metastatic effects of baicalein, quantitative polymerase chain reaction (qPCR) and western blot analyses were performed to examine the effect on the expression of TGF‑β, Smad4, N-cadherin, vimentin, ZEB1 and ZEB2. It was determined that baicalein inhibited the migration and invasion of AGS cells by suppressing the TGF-β/Smad4 signaling pathway. In addition, baicalein treatment reduced the expression of the metastasis-associated N-cadherin, vimentin, ZEB1 and ZEB2, downstream target genes of the TGF‑β/Smad4 signaling pathway. Collectively, these results suggest that inhibition of the metastasis of cancer cells via inactivation of TGF-β/Smad4 signaling is one of the mechanisms by which baicalein may treat cancer.

Khoi PN, Xia Y, Lian S, et al.
Cadmium induces urokinase-type plasminogen activator receptor expression and the cell invasiveness of human gastric cancer cells via the ERK-1/2, NF-κB, and AP-1 signaling pathways.
Int J Oncol. 2014; 45(4):1760-8 [PubMed] Related Publications
Cadmium exposure has been linked to human cancers, including stomach cancer. In this study, the effects of cadmium on urokinase-type plasminogen activator receptor (uPAR) expression in human gastric cancer cells and the underlying signal transduction pathways were investigated. Cadmium induced uPAR expression in a time- and concentration-dependent manner. Cadmium also induced uPAR promoter activity. Additionally, cadmium induced the activation of extracellular signal regulated kinase-1/2 (ERK-1/2), p38 mitogen-activated protein kinase (MAPK), and the activation of c-Jun amino terminal kinase (JNK). A specific inhibitor of MEK-1 (PD98059) inhibited cadmium-induced uPAR expression, while JNK and p38 MAPK inhibitors did not. Expression vectors encoding dominant-negative MEK-1 (pMCL-K97M) also prevented cadmium-induced uPAR promoter activity. Site-directed mutagenesis and electrophoretic mobility shift studies showed that sites for the transcription factors nuclear factor (NF)-κB and activator protein-1 (AP-1) were involved in cadmium-induced uPAR transcription. Suppression of the cadmium-induced uPAR promoter activity by a mutated-type NF-κB-inducing kinase and I-κB and an AP-1 decoy oligonucleotide confirmed that the activation of NF-κB and AP-1 are essential for cadmium-induced uPAR upregulation. Cells pretreated with cadmium showed markedly enhanced invasiveness and this effect was partially abrogated by uPAR-neutralizing antibodies and by inhibitors of ERK-1/2, NF-κB, and AP-1. These results suggest that cadmium induces uPAR expression via ERK-1/2, NF-κB, and AP-1 signaling pathways and, in turn, stimulates cell invasiveness in human gastric cancer AGS cells.

Lee NK, Lee JH, Park CH, et al.
Long non-coding RNA HOTAIR promotes carcinogenesis and invasion of gastric adenocarcinoma.
Biochem Biophys Res Commun. 2014; 451(2):171-8 [PubMed] Related Publications
Gastric cancer is one of the major causes of cancer death worldwide; however, the mechanism of carcinogenesis is complex and poorly understood. Long non-coding RNA HOTAIR (HOX transcript antisense RNA) recently emerged as a promoter of metastasis in various cancers including gastric cancer. Here we investigated the impact of HOTAIR on apoptosis, cell proliferation and cell cycle to dissect the carcinogenesis of gastric cancer. We examined the mechanism of invasion and metastasis and analyzed the clinical significance of HOTAIR. Downregulation of HOTAIR was confirmed by two different siRNAs. The expression of HOTAIR was significantly elevated in various gastric cancer cell lines and tissues compared to normal control. si-HOTAIR significantly reduced viability in MKN 28, MKN 74, and KATO III cells but not in AGS cells. si-HOTAIR induced apoptosis in KATO III cells. Lymphovascular invasion and lymph node metastasis were more common in the high level of HOTAIR group. si-HOTAIR significantly decreased invasiveness and migration. si-HOTAIR led to differential expression of epithelial to mesenchymal transition markers. We found that HOTAIR was involved in inhibition of apoptosis and promoted invasiveness, supporting a role for HOTAIR in carcinogenesis and progression of gastric cancer.

Zhou Z, Ji Z, Wang Y, et al.
TRIM59 is up-regulated in gastric tumors, promoting ubiquitination and degradation of p53.
Gastroenterology. 2014; 147(5):1043-54 [PubMed] Related Publications
BACKGROUND & AIMS: Little is known about factors that promote gastric carcinogenesis. We analyzed multiple microarray data sets for messenger RNAs (mRNAs) that were increased significantly in human gastric tumor samples, compared with the adjacent normal gastric tissue. We found expression of tripartite motif 59 (TRIM59), which encodes a putative ubiquitin ligase, to be increased, and investigated its effects in gastric cancer cell lines.
METHODS: We analyzed microarray data sets from the Oncomine database. We used quantitative polymerase chain reaction and immunoblotting to measure levels of TRIM59 mRNA and protein in 50 human gastric cancer and paired normal tissues, obtained from Renji Hospital and the First Affiliated Hospital of Nanchang University, in China. We also measured protein levels in the gastric epithelial cell line GES-1; the cancer cell lines MKN45, AGS, SGC7901, BGC823, Snu5, N87, and Snu1; and in tissue arrays of 108 human gastric tumors. TRIM59 was knocked down and overexpressed in gastric cancer cell lines, and the effects on proliferation, clone formation, migration, and growth of xenograft tumors in nude mice were assessed. TRIM59-related signaling pathways were examined by immunoblotting and quantitative polymerase chain reaction. We analyzed interactions among TRIM59, P53, and ubiquitin in immunoprecipitation studies.
RESULTS: Levels of TRIM59 mRNA and protein were increased significantly in gastric tumors compared with nontumor tissues; increased levels were associated with advanced tumor stage and shorter patient survival times. TRIM59 knockdown reduced proliferation, clone formation, and migration of gastric cancer cell lines, as well as growth of xenograft tumors in nude mice; overexpression of TRIM59 had the opposite effects. TRIM59 interacted physically with P53, increasing its ubiquitination and degradation. Increased levels of TRIM59 in human gastric tumors correlated with reduced expression of P53 target genes.
CONCLUSIONS: The putative ubiquitin ligase TRIM59 is up-regulated in human gastric tumors compared with nontumor tissues. Levels of TRIM59 correlate with tumor progression and patient survival times. TRIM59 interacts with P53, promoting its ubiquitination and degradation, and TRIM59 might promote gastric carcinogenesis via this mechanism.

Mirzaei MR, Najafi A, Arababadi MK, et al.
Altered expression of apoptotic genes in response to OCT4B1 suppression in human tumor cell lines.
Tumour Biol. 2014; 35(10):9999-10009 [PubMed] Related Publications
OCT4B1 is a newly discovered spliced variant of OCT4 which is primarily expressed in pluripotent and tumor cells. Based on our previous studies, OCT4B1 is significantly overexpressed in tumors, where it endows an anti-apoptotic property to tumor cells. However, the mechanism by which OCT4B1 regulates the apoptotic pathway is not yet elucidated. Here, we investigated the effects of OCT4B1 suppression on the expression alteration of 84 genes involved in apoptotic pathway. The AGS (gastric adenocarcinoma), 5637 (bladder tumor), and U-87MG (brain tumor) cell lines were transfected with OCT4B1 or irrelevant siRNAs. The expression level of apoptotic genes was then quantified using a human apoptosis panel-PCR kit. Our data revealed an almost similar pattern of alteration in the expression profile of apoptotic genes in all three studied cell lines, following OCT4B1 suppression. In general, the expression of more than 54 apoptotic genes (64 % of arrayed genes) showed significant changes. Among these, some up-regulated (CIDEA, CIDEB, TNFRSF1A, TNFRSF21, TNFRSF11B, TNFRSF10B, and CASP7) and down-regulated (BCL2, BCL2L11, TP73, TP53, BAD, TRAF3, TRAF2, BRAF, BNIP3L, BFAR, and BAX) genes had on average more than tenfold gene expression alteration in all three examined cell lines. With some minor exceptions, suppression of OCT4B1 caused upregulation of pro-apoptotic and down-regulation of anti-apoptotic genes in transfected tumor cells. Uncovering OCT4B1 down-stream targets could further elucidate its part in tumorigenesis, and could lead to finding a new approach to combat cancer, based on targeting OCT4B1.

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