DMBT1

Gene Summary

Gene:DMBT1; deleted in malignant brain tumors 1
Aliases: SAG, GP340, SALSA, muclin
Location:10q26.13
Summary:Loss of sequences from human chromosome 10q has been associated with the progression of human cancers. This gene was originally isolated based on its deletion in a medulloblastoma cell line. This gene is expressed with transcripts of 6.0, 7.5, and 8.0 kb in fetal lung and with one transcript of 8.0 kb in adult lung, although the 7.5 kb transcript has not been characterized. The encoded protein precursor is a glycoprotein containing multiple scavenger receptor cysteine-rich (SRCR) domains separated by SRCR-interspersed domains (SID). Transcript variant 2 (8.0 kb) has been shown to bind surfactant protein D independently of carbohydrate recognition. This indicates that DMBT1 may not be a classical tumor suppressor gene, but rather play a role in the interaction of tumor cells and the immune system. [provided by RefSeq, Mar 2016]
Databases:OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:deleted in malignant brain tumors 1 protein
Source:NCBIAccessed: 31 August, 2019

Ontology:

What does this gene/protein do?
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Cancer Overview

Research Indicators

Publications Per Year (1994-2019)
Graph generated 31 August 2019 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.

Tag cloud generated 31 August, 2019 using data from PubMed, MeSH and CancerIndex

Specific Cancers (9)

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

Entity Topic PubMed Papers
Brain and CNS TumoursDMBT1 and Brain Stem Glioma View Publications34
Brain and CNS TumoursDMBT1 and Brain Tumours
Chromosome 10q losses are frequently seen in CNS tumours, particularly in glioblastoma multiforme. Mollenhauer (1997) identidied a novel candidate gene, DMBT1, deleted at 10q25.3-26.1 in a medulloblastoma cell line. They cloned the gene and identified intragenic homozygous deletions were detected in 2/20 medulloblastomas and in 9/39 glioblastomas multiformes.
View Publications34
Brain and CNS TumoursDMBT1 and Brain, Astrocytoma View Publications18
Brain and CNS TumoursDMBT1 and Glioblastoma View Publications14
Lung CancerDMBT1 and Lung Cancer View Publications7
Breast CancerDMBT1 and Breast Cancer View Publications7
Esophageal CancerDMBT1 supression in Esophageal Cancer? View Publications3
Stomach CancerDMBT1 and Stomach Cancer View Publications3
Skin CancerDMBT1 and Skin Cancer View Publications2

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

Latest Publications: DMBT1 (cancer-related)

Xiang XH, Yang L, Zhang X, et al.
Seven-senescence-associated gene signature predicts overall survival for Asian patients with hepatocellular carcinoma.
World J Gastroenterol. 2019; 25(14):1715-1728 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Cellular senescence is a recognized barrier for progression of chronic liver diseases to hepatocellular carcinoma (HCC). The expression of a cluster of genes is altered in response to environmental factors during senescence. However, it is questionable whether these genes could serve as biomarkers for HCC patients.
AIM: To develop a signature of senescence-associated genes (SAGs) that predicts patients' overall survival (OS) to improve prognosis prediction of HCC.
METHODS: SAGs were identified using two senescent cell models. Univariate COX regression analysis was performed to screen the candidate genes significantly associated with OS of HCC in a discovery cohort (GSE14520) for the least absolute shrinkage and selection operator modelling. Prognostic value of this seven-gene signature was evaluated using two independent cohorts retrieved from the GEO (GSE14520) and the Cancer Genome Atlas datasets, respectively. Time-dependent receiver operating characteristic (ROC) curve analysis was conducted to compare the predictive accuracy of the seven-SAG signature and serum α-fetoprotein (AFP).
RESULTS: A total of 42 SAGs were screened and seven of them, including
CONCLUSION: We developed a seven-SAG signature, which could predict OS of Asian HCC patients. This risk model provides new clinical evidence for the accurate diagnosis and targeted treatment of HCC.

Ayón-Pérez MF, Pimentel-Gutiérrez HJ, Durán-Avelar MJ, et al.
IKZF1 Gene Deletion in Pediatric Patients Diagnosed with Acute Lymphoblastic Leukemia in Mexico.
Cytogenet Genome Res. 2019; 158(1):10-16 [PubMed] Related Publications
The IKZF1 gene is formed by 8 exons and encodes IKAROS, a transcription factor that regulates the expression of genes that control cell cycle progression and cell survival. In general, 15-20% of the patients with preB acute lymphoblastic leukemia (preB ALL) harbor IKZF1 deletions, and the frequency of these deletions increases in BCR-ABL1 or Ph-like subgroups. These deletions have been associated with poor treatment response and the risk of relapse. The aim of this descriptive study was to determine the frequency of IKZF1 deletions and the success of an induction therapy response in Mexican pediatric patients diagnosed with preB ALL in 2 hospitals from 2017 to August 2018. Thirty-six bone marrow samples from patients at the Instituto Nacional de Pediatría in Mexico City and the Centro Estatal de Cancerología in Tepic were analyzed. The IKZF1 deletion was identified by MLPA using the SALSA MLPA P335 ALL-IKZF1 probemix. Deletions of at least 1 IKZF1 exon were observed in 7/34 samples (20.6%): 3 with 1 exon deleted; 1 with 2 exons, 1 with 5 exons, 1 with 6 exons, and 1 patient with a complete IKZF1 deletion. This study was descriptive in nature; we calculated the frequency of the IKZF1 gene deletion in a Mexican pediatric population with preB ALL as 20.6%.

Baldin AV, Grishina AN, Korolev DO, et al.
Autoantibody against arrestin-1 as a potential biomarker of renal cell carcinoma.
Biochimie. 2019; 157:26-37 [PubMed] Related Publications
Renal cell carcinoma (RCC) is the second-most common uronephrological cancer. In the absence of specific symptoms, early diagnosis of RCC is challenging. Monitoring of the aberrant expression of tumour-associated antigens (TAAs) and related autoantibody response is considered as a novel approach of RCC diagnostics. The aim of this study was to examine the aberrant expression of arrestin-1 in renal tumours, to investigate the possible epigenetic mechanism underlying arrestin-1 expression, and to assess the frequency of anti-arrestin-1 autoantibody response. Immunohistochemistry was used to assess the presence of arrestin-1 in primary tumours and metastases of 39 patients with RCC and renal oncocytoma. Bisulfite sequencing was employed to analyse the methylation status of the promoter of the SAG gene encoding arrestin-1. Western blot analysis was performed to detect autoantibodies against arrestin-1 in serum samples of 36 RCC and oncocytoma patients. Arrestin-1 was found to be expressed in RCC (58.7% of cases) and renal oncocytoma (90% of cases) cells, while being absent in healthy kidney. The expression of arrestin-1 in RCC metastases was more prominent than in primary tumours. Hypomethylation of the SAG gene promoter is unlikely to be the mechanism for the aberrant expression of arrestin-1. Autoantibodies against arrestin-1 were detected in sera of 75% of RCC patients. Taken together, our findings suggest employment of autoantibody against arrestin-1 as biomarker of RCC.

Park HS, Kim BC, Yeo HY, et al.
Deleted in malignant brain tumor 1 is a novel prognostic marker in colorectal cancer.
Oncol Rep. 2018; 39(5):2279-2287 [PubMed] Related Publications
The gene deleted in malignant brain tumor 1 (DMBT1) encoding a large scavenger receptor cysteine-rich protein was originally identified based on its deletion in a brain tumor cell line. The DMBT1 protein is involved in mucosal immune defense, epithelial differentiation and tumor suppression. In the present study, the clinicopathologic significance of DMBT1 protein expression in stool and tissue samples of colorectal cancer (CRC) patients was evaluated. Western blot analysis of fecal DMBT1 was performed for patients with CRC (n=177), colorectal adenoma (n=61), inflammatory bowel diseases (IBDs; n=54) and healthy individuals as the control group (n=151). Immunohistochemical analysis of tissue expression of DMBT1 was performed in 385 primary CRC tissues. Fecal DMBT1 expression was higher in CRC and IBD patients than in healthy controls or adenoma patients (P<0.0001), but not significantly different between IBD and CRC or between adenoma and healthy control groups. In CRC patients, fecal DMBT1 expression was not associated with the tumor stage or site. The sensitivity of fecal DMBT1 analysis for CRC was 50%, while the specificity and positive predictive value were 86.8 and 81.3%, respectively. Immunohistochemical expression patterns of DMBT1 in CRC tissues varied from loss to overexpression. Loss of expression was observed in 4.7% (18 out of 385 cases) and significantly associated with lymph node metastasis (P=0.016), distant metastasis (P=0.013), advanced stage (P=0.026), and higher histologic grade (P=0.033). In addition, DMBT1 loss was an independent poor prognostic factor for cancer-associated death (hazard ratio, 2.272; P=0.015) and disease recurrence (hazard ratio, 2.689; P=0.009). In conclusion, fecal DMBT1 has limited value as a diagnostic biomarker, while the tissue expression of DMBT1 may serve as an efficient prognostic marker for CRC. Furthermore, DMBT1 may have a role in the progression of CRC.

Schulten HJ, Bangash M, Karim S, et al.
Comprehensive molecular biomarker identification in breast cancer brain metastases.
J Transl Med. 2017; 15(1):269 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Breast cancer brain metastases (BCBM) develop in about 20-30% of breast cancer (BC) patients. BCBM are associated with dismal prognosis not at least due to lack of valuable molecular therapeutic targets. The aim of the study was to identify new molecular biomarkers and targets in BCBM by using complementary state-of-the-art techniques.
METHODS: We compared array expression profiles of three BCBM with 16 non-brain metastatic BC and 16 primary brain tumors (prBT) using a false discovery rate (FDR) p < 0.05 and fold change (FC) > 2. Biofunctional analysis was conducted on the differentially expressed probe sets. High-density arrays were employed to detect copy number variations (CNVs) and whole exome sequencing (WES) with paired-end reads of 150 bp was utilized to detect gene mutations in the three BCBM.
RESULTS: The top 370 probe sets that were differentially expressed between BCBM and both BC and prBT were in the majority comparably overexpressed in BCBM and included, e.g. the coding genes BCL3, BNIP3, BNIP3P1, BRIP1, CASP14, CDC25A, DMBT1, IDH2, E2F1, MYCN, RAD51, RAD54L, and VDR. A number of small nucleolar RNAs (snoRNAs) were comparably overexpressed in BCBM and included SNORA1, SNORA2A, SNORA9, SNORA10, SNORA22, SNORA24, SNORA30, SNORA37, SNORA38, SNORA52, SNORA71A, SNORA71B, SNORA71C, SNORD13P2, SNORD15A, SNORD34, SNORD35A, SNORD41, SNORD53, and SCARNA22. The top canonical pathway was entitled, role of BRCA1 in DNA damage response. Network analysis revealed key nodes as Akt, ERK1/2, NFkB, and Ras in a predicted activation stage. Downregulated genes in a data set that was shared between BCBM and prBT comprised, e.g. BC cell line invasion markers JUN, MMP3, TFF1, and HAS2. Important cancer genes affected by CNVs included TP53, BRCA1, BRCA2, ERBB2, IDH1, and IDH2. WES detected numerous mutations, some of which affecting BC associated genes as CDH1, HEPACAM, and LOXHD1.
CONCLUSIONS: Using complementary molecular genetic techniques, this study identified shared and unshared molecular events in three highly aberrant BCBM emphasizing the challenge to detect new molecular biomarkers and targets with translational implications. Among new findings with the capacity to gain clinical relevance is the detection of overexpressed snoRNAs known to regulate some critical cellular functions as ribosome biogenesis.

Ergin K, Aktaş S, Altun Z, et al.
MicroRNA profiles in neuroblastoma: Differences in risk and histology groups.
Asia Pac J Clin Oncol. 2018; 14(5):e374-e379 [PubMed] Related Publications
AIM: To determine the miRNA expression profiles of neuroblastomas with different clinical and histological characteristics.
METHODS: In this study 24 samples from 17 patients, paraffin blocks were used. Their microRNA profiles were compared by five different analysis: analysis I: well-poorly differentiated, analysis II: before-after chemotherapy, analysis III: favorable-unfavorable histology, analysis IV: neuroblastoma-ganglioneuroma, analysis V: low-risk-middle-risk-high risk groups. Clinical data were compared with differentially expressed microRNAs.
RESULTS: It was found that 25 miRNAs between well-poorly differentiated tumors, eight miRNAs before and after of the chemotherapy, three miRNAs between favorable and unfavorable histology, four miRNAs between neuroblastoma and ganglioneuroma, seven miRNAs between low and middle risk, one miRNA between middle and high risk, 14 miRNAs between low and high risk were differently expressed (P < 0.01). These miRNA's targeted mostly the cancer pathway by the KEGG pathway analysis. The most marked difference was seen in miR-132 and miR-490, comparing the clinical data and all microRNAs. The most fold change was detected at miR-98-5p between the tissues of high- and low-risk patients.
CONCLUSION: In this study, we represent microRNA expression profiles of neuroblastoma patients' tissue with different clinical, histological grade, differentiation, and treatment status, and which could be informative for new therapies targeting microRNAs.

Hasegawa D, Ochiai-Shino H, Onodera S, et al.
Gorlin syndrome-derived induced pluripotent stem cells are hypersensitive to hedgehog-mediated osteogenic induction.
PLoS One. 2017; 12(10):e0186879 [PubMed] Free Access to Full Article Related Publications
Gorlin syndrome is an autosomal dominant inherited syndrome that predisposes a patient to the formation of basal cell carcinomas, odontogenic keratocysts, and skeletal anomalies. Causative mutations in several genes associated with the sonic hedgehog (SHH) signaling pathway, including PTCH1, have been identified in Gorlin syndrome patients. However, no definitive genotype-phenotype correlations are evident in these patients, and their clinical presentation varies greatly, often leading to delayed diagnosis and treatment. We generated iPSCs from four unrelated Gorlin syndrome patients with loss-of-function mutations in PTCH1 using the Sendai virus vector (SeVdp(KOSM)302). The patient-derived iPSCs exhibited basic iPSC features, including stem cell marker expression, totipotency, and the ability to form teratomas. GLI1 expression levels were greater in fibroblasts and patient-derived iPSCs than in the corresponding control cells. Patient-derived iPSCs expressed lower basal levels than control iPSCs of the genes encoding the Hh ligands Indian Hedgehog (IHH) and SHH, the Hh acetyltransferase HHAT, Wnt proteins, BMP4, and BMP6. Most of these genes were upregulated in patient-derived iPSCs grown in osteoblast differentiation medium (OBM) and downregulated in control iPSCs cultured in OBM. The expression of GLI1 and GLI2 substantially decreased in both control and patient-derived iPSCs cultured in OBM, whereas GLI3, SHH, and IHH were upregulated in patient-derived iPSCs and downregulated in control iPSCs grown in OBM. Activation of Smoothened by SAG in cells grown in OBM significantly enhanced alkaline phosphatase activity in patient-derived iPSCs compared with control iPSC lines. In summary, patient-derived iPSCs expressed lower basal levels than the control iPSCs of the genes encoding Hh, Wnt, and bone morphogenetic proteins, but their expression of these genes strongly increased under osteogenic conditions. These findings indicate that patient-derived iPSCs are hypersensitive to osteogenic induction. We propose that Hh signaling is constituently active in iPSCs from Gorlin syndrome patients, enhancing their response to osteogenic induction and contributing to disease-associated abnormalities.

Lavrov AV, Ustaeva OA, Adilgereeva EP, et al.
Copy number variation analysis in cytochromes and glutathione S-transferases may predict efficacy of tyrosine kinase inhibitors in chronic myeloid leukemia.
PLoS One. 2017; 12(9):e0182901 [PubMed] Free Access to Full Article Related Publications
Chronic myeloid leukemia (CML) is a myeloproliferative disease characterized by the presence of BCR/ABL fusion gene in leukemic cells, which promotes uncontrolled cell proliferation. Up to 20% of CML patients show primary resistance or non-optimal response to tyrosine kinase inhibitor (TKI) therapy. We investigated the association between copy number variation (CNV) in glutathione S-transferases (GST) and cytochromes (CYP) and the response rate to TKI. We enrolled 47 patients with CML: 31 with an optimal response and 16 with failure at 6 months in accordance with European LeukemiaNet 2013 recommendations. CNV detection was performed using SALSA MLPA P128-C1 Cytochrome P450 probe mix. Patients with optimal response and with failure of TKI therapy showed different frequencies of wild type and mutated CYPs and GST (p<0.0013). Validation in the group of 15 patients proved high prognostic value (p = 0.02): positive and negative predictive value 83% and 78%; sensitivity and specificity 71% and 88%. Wild type genotypes of CYP and GST associate with a worse response to TKI treatment in CML patients. This test can be recommended for further clinical trials.

Vázquez-Reyes A, Bobadilla-Morales L, Barba-Barba C, et al.
Aneuploidy identification in pre-B acute lymphoblastic leukemia patients at diagnosis by Multiplex Ligation-dependent Probe Amplification (MLPA).
Leuk Res. 2017; 59:117-123 [PubMed] Related Publications
Three-quarters of the patients with acute lymphoblastic leukemia (ALL), show numerical or structural chromosomal alterations, which are important factors in leukemogenesis. The use of Multiplex Ligation-dependent Probes Amplification (MLPA) has been mainly limited for searching copy number alterations of genes, suggesting that MLPA could detect numerical alterations in cancer. However, the use of MLPA in pediatrics to analyze subtelomeric sequences for aneuploidy detection has not been considered in previous studies. The aim of this study was to identify aneuploidy for the first time using MLPA and correlate the results with karyotype and DNA-index (DI), from preB ALL patients. Forty-two bone marrow samples were analyzed by cytogenetics and flow cytometry to determine the DI. The chromosomal gains and/or losses were detected by the SALSA MLPA P036 Subtelomere Mix 1 probemix

Garay J, Piazuelo MB, Lopez-Carrillo L, et al.
Increased expression of deleted in malignant brain tumors (DMBT1) gene in precancerous gastric lesions: Findings from human and animal studies.
Oncotarget. 2017; 8(29):47076-47089 [PubMed] Free Access to Full Article Related Publications
Helicobacter pylori infection triggers a cascade of inflammatory stages that may lead to the appearance of non-atrophic gastritis, multifocal atrophic, intestinal metaplasia, dysplasia, and cancer. Deleted in malignant brain tumors 1 (DMBT1) belongs to the group of secreted scavenger receptor cysteine-rich proteins and is considered to be involved in host defense by binding to pathogens. Initial studies showed its deletion and loss of expression in a variety of tumors but the role of this gene in tumor development is not completely understood. Here, we examined the role of DMBT1 in gastric precancerous lesions in Caucasian, African American and Hispanic individuals as well as in the development of gastric pathology in a mouse model of H. pylori infection. We found that in 3 different populations, mucosal DMBT1 expression was significantly increased (2.5 fold) in individuals with dysplasia compared to multifocal atrophic gastritis without intestinal metaplasia; the increase was also observed in individuals with advanced gastritis and positive H. pylori infection. In our animal model, H. pylori infection of Dmbt1-/- mice resulted in significantly higher levels of gastritis, more extensive mucous metaplasia and reduced Il33 expression levels in the gastric mucosa compared to H. pylori-infected wild type mice. Our data in the animal model suggest that in response to H. pylori infection DMBT1 may mediate mucosal protection reducing the risk of developing gastric precancerous lesions. However, the increased expression in human gastric precancerous lesions points to a more complex role of DMBT1 in gastric carcinogenesis.

Naru J, Aggarwal R, Mohanty AK, et al.
Identification of differentially expressed proteins in retinoblastoma tumors using mass spectrometry-based comparative proteomic approach.
J Proteomics. 2017; 159:77-91 [PubMed] Related Publications
In India, retinoblastoma is among the top five childhood cancers. Children mostly present with extraocular extension and high risk features that results in unsatisfactory treatment and low survival rate. In addition, lack of potential therapeutic and prognostic targets is another challenge in the management of retinoblastoma. We studied comparative proteome of retinoblastoma patients (HPV positive and negative (n=4 each) and controls (n=4), in order to identify potential retinoblastoma-specific protein targets. 2D-DIGE coupled MALDI-TOF/TOF mass spectrometry identified 39 unique proteins. Highly deregulated proteins were GFAP,RBP3,APOA1,CRYAA,CRABP1,SAG and TF. Gene ontology (Panther 7.0) revealed majority of proteins to be associated with metabolic processes (26%) and catalytic activity (38%). 8 proteins were significantly upregulated in HPV positive vis-a-vis HPV negative cases. Patient group exhibited 12 upregulated and 18 downregulated proteins compared to controls. Pathway and network analysis (IPA software) revealed CTNNB1 as most significantly regulated signalling pathway in HPV positive than HPV negative retinoblastoma. The trends in transcriptional change of 9 genes were consistent with those at proteomic level. The Western blot analysis confirmed the expression pattern of RBP3,GFAP and CRABP1. We suggest GFAP,RBP3,CRABP1,CRYAAA,APOA1 and SAG as prospective targets that could further be explored as potential candidates in therapy and may further assist in studying the disease mechanism.
SIGNIFICANCE: In this study we evaluated tumor tissue specimens from retinoblastoma patients and identified 39 differentially regulated proteins compared to healthy retina. From these, we propose RBP3, CRABP1, GFAP, CRYAA, APOA1 and SAG as promising proteomic signatures that could further be explored as efficient prognostic and therapeutic targets in retinoblastoma. The present study is not only a contribution to the ongoing endeavour for the discovery of proteomic signatures in retinoblastoma, but, may also act as a starting point for future studies aimed at uncovering novel targets for further therapeutic interventions and improving patient outcomes.

Tan M, Xu J, Siddiqui J, et al.
Depletion of SAG/RBX2 E3 ubiquitin ligase suppresses prostate tumorigenesis via inactivation of the PI3K/AKT/mTOR axis.
Mol Cancer. 2016; 15(1):81 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: SAG (Sensitive to Apoptosis Gene), also known as RBX2, ROC2 or RNF7, is a RING component of CRL (Cullin-RING ligase), required for its activity. Our recent study showed that SAG/RBX2 co-operated with Kras to promote lung tumorigenesis, but antagonized Kras to inhibit skin tumorigenesis, suggesting a tissue/context dependent function of Sag. However, it is totally unknown whether and how Sag would play in prostate tumorigenesis, triggered by Pten loss.
METHODS: Sag and Pten double conditional knockout mice were generated and prostate specific deletion of Sag and Pten was achieved by PB4-Cre, and their effect on prostate tumorigenesis was evaluated by H&E staining. The methods of immunohistochemistry (IHC) staining and Western blotting were utilized to examine expression of various proteins in prostate cancer tissues or cell lines. The effect of SAG knockdown in proliferation, survival and migration was evaluated in two prostate cancer cell lines. The poly-ubiquitylation of PHLPP1 and DEPTOR was evaluated by both in vivo and in vitro ubiquitylation assays.
RESULTS: SAG is overexpressed progressively from early-to-late stage of human prostate cancer with the highest expression seen in metastatic lesion. Sag deletion inhibits prostate tumorigenesis triggered by Pten loss in a mouse model as a result of suppressed proliferation. SAG knockdown in human prostate cancer cells inhibits a) proliferation in monolayer and soft agar, b) clonogenic survival, and c) migration. SAG is an E3 ligase that promotes ubiquitylation and degradation of PHLPP1 and DEPTOR, leading to activation of the PI3K/AKT/mTOR axis, whereas SAG knockdown caused their accumulation. Importantly, growth suppression triggered by SAG knockdown was partially rescued by simultaneous knockdown of PHLPP1 or DEPTOR, suggesting their causal role. Accumulation of Phlpp1 and Deptor with corresponding inactivation of Akt/mTOR was also detected in Sag-null prostate cancer tissues.
CONCLUSIONS: Sag is an oncogenic cooperator of Pten-loss for prostate tumorigenesis. Targeting SAG E3 ligase may, therefore, have therapeutic value for the treatment of prostate cancer associated with Pten loss.

Shen S, Liu H, Wang Y, et al.
Long non-coding RNA CRNDE promotes gallbladder carcinoma carcinogenesis and as a scaffold of DMBT1 and C-IAP1 complexes to activating PI3K-AKT pathway.
Oncotarget. 2016; 7(45):72833-72844 [PubMed] Free Access to Full Article Related Publications
Deleted in malignant brain tumors 1 (DMBT1) is deleted during cancer progression and as a potential tumor-suppressor gene in various types of cancer. However, its role in Gallbladder cancer remains poorly understood. DMBT1 has low-expression and deletion of copy number were detected in normal tissues and GBC cancer tissues by qRT-PCR. Knockdown of DMBT1 increased migration and invasion and overexpressed DMBT1 impaired migration and invasion in GBC cells. We also evaluated the molecular mechanism of DMBT1 by RNA sequencing and GSEA analysis. RNA-Pulldown and RIP assay authenticated CRNDE can specified binding with DMBT1 and c-IAP1. Downregulation of DMBT1 resulted in significant change of gene expression (at least 2-fold) in PI3K-AKT pathway, increased expression of MMP-9, JUK-1, ERK and AKT, activating PI3K-AKT pathway lead to GBC carcinogenesis.We for the first time reported, DMBT1 as a prognosis biomarker, is low-expressed in GBC tumors, and CRNDE act as a scaffold to recruit the DMBT1 and c-IAP1, promotes the PI3K-AKT pathway. Our study reveals DMBT1 may be an important contributor to GBC cancer development.

Lorenzo D, Duarte A, Mundiñano J, et al.
A B-Cell Superantigen Induces the Apoptosis of Murine and Human Malignant B Cells.
PLoS One. 2016; 11(9):e0162456 [PubMed] Free Access to Full Article Related Publications
B-cell superantigens (Sags) bind to conserved sites of the VH or VL regions of immunoglobulin molecules outside their complementarity-determining regions causing the apoptosis of normal cognate B cells. No attempts to investigate whether B-cell Sags are able to induce the apoptosis of cognate malignant B cells were reported. In the present study we show that protein L (PpL), secreted by Finegoldia magna, a B-cell Sag which interacts with κ+ bearing cells, induces the apoptosis of murine and human κ+ lymphoma B cells both in vitro and in vivo. Apoptosis was not altered by caspase-8 inhibitor. No alterations in the levels of Bid, Fas and Fas-L were found suggesting that PpL does not activate the extrinsic pathway of apoptosis. The involvement of the intrinsic pathway was clearly indicated by: i) alterations in mitochondrial membrane potential (ΔΨm) both in murine and human lymphoma cells exposed to PpL; ii) decreased levels of apoptosis in the presence of caspase-9 inhibitor; iii) significant increases of Bim and Bax protein levels and downregulation of Bcl-2; iv) the translocation from the cytoplasm to the mitochondria of Bax and Bim pro-apoptotic proteins and its inhibition by caspase-9 inhibitor but not by caspase-8 inhibitor and v) the translocation of Bcl-2 protein from the mitochondria to the cytosol and its inhibition by caspase-9 inhibitor but not by caspase-8 inhibitor. The possibility of a therapeutic use of Sags in lymphoma/leukemia B cell malignancies is discussed.

Zhou W, Xu J, Li H, et al.
Neddylation E2 UBE2F Promotes the Survival of Lung Cancer Cells by Activating CRL5 to Degrade NOXA via the K11 Linkage.
Clin Cancer Res. 2017; 23(4):1104-1116 [PubMed] Free Access to Full Article Related Publications

Gorukmez O, Yakut T, Gorukmez O, et al.
Distribution of KRAS and BRAF Mutations in Metastatic Colorectal Cancers in Turkish Patients.
Asian Pac J Cancer Prev. 2016; 17(3):1175-9 [PubMed] Related Publications
The results of this study demonstrate the potential prognostic and predictive values of KRAS and BRAF gene mutations in patients with colorectal cancer (CRC). It has been proven that KRAS and BRAF mutations are predictive biomarkers for resistance to anti-EGFR monoclonal antibody treatment in patients with metastatic CRC (mCRC). We demonstrated the distribution of KRAS (codons 12, 13 and 61) and BRAF (codon 600) gene mutations in 50 mCRCs using direct sequencing and compared the results with clinicopathological data. KRAS and BRAF mutations were identified in 15 (30%) and 1 (2%) patients, respectively. We identified KRAS mutations in codon 12, 13 and 61 in 73.3% (11/15), 20% (3/15) and 6.67% (1/15) of the positive patients, respectively. The KRAS mutation frequency was significantly higher in tumors located in the ascending colon (p=0.043). Thus, we found that approximately 1/3 of the patients with mCRC had KRAS mutations and the only clinicopathological factor related to this mutation was tumor location. Future studies with larger patient groups should yield more accurate data regarding the molecular mechanism of CRC and the association between KRAS and BRAF mutations and clinicopathological features.

Zauber P, Marotta S, Sabbath-Solitare M
Copy number of the Adenomatous Polyposis Coli gene is not always neutral in sporadic colorectal cancers with loss of heterozygosity for the gene.
BMC Cancer. 2016; 16:213 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Changes in the number of alleles of a chromosome may have an impact upon gene expression. Loss of heterozygosity (LOH) indicates that one allele of a gene has been lost, and knowing the exact copy number of the gene would indicate whether duplication of the remaining allele has occurred. We were interested to determine the copy number of the Adenomatous Polyposis Coli (APC) gene in sporadic colorectal cancers with LOH.
METHODS: We selected 38 carcinomas with LOH for the APC gene region of chromosome 5, as determined by amplification of the CA repeat region within the D5S346 loci. The copy number status of APC was ascertained using the SALSA® MLPA® P043-B1 APC Kit. LOH for the DCC gene, KRAS gene mutation, and microsatellite instability were also evaluated for each tumor, utilizing standard polymerase chain reaction methods.
RESULTS: No tumor demonstrated microsatellite instability. LOH of the DCC gene was also present in 33 of 36 (91.7%) informative tumors. A KRAS gene mutation was present in 16 of the 38 (42.1%) tumors. Twenty-four (63.2%) of the tumors were copy number neutral, 10 (26.3%) tumors demonstrated major loss, while two (5.3%) showed partial loss. Two tumors (5.3%) had copy number gain.
CONCLUSIONS: Results of APC and DCC LOH, KRAS and microsatellite instability indicate our colorectal cancer cases were typical of sporadic cancers following the 'chromosomal instability' pathway. The majority of our colorectal carcinomas with LOH for APC gene are copy number neutral. However, one-third of our cases showed copy number loss, suggesting that duplication of the remaining allele is not required for the development of a colorectal carcinoma.

Pharoah PDP, Song H, Dicks E, et al.
PPM1D Mosaic Truncating Variants in Ovarian Cancer Cases May Be Treatment-Related Somatic Mutations.
J Natl Cancer Inst. 2016; 108(3) [PubMed] Free Access to Full Article Related Publications
Mosaic truncating mutations in the protein phosphatase, Mg(2+)/Mn(2+)-dependent, 1D (PPM1D) gene have recently been reported with a statistically significantly greater frequency in lymphocyte DNA from ovarian cancer case patients compared with unaffected control patients. Using massively parallel sequencing (MPS) we identified truncating PPM1D mutations in 12 of 3236 epithelial ovarian cancer (EOC) case patients (0.37%) but in only one of 3431 unaffected control patients (0.03%) (P = .001). All statistical tests were two-sided. A combination of Sanger sequencing, pyrosequencing, and MPS data suggested that 12 of the 13 mutations were mosaic. All mutations were identified in post-chemotherapy treatment blood samples from case patients (n = 1827) (average 1234 days post-treatment in carriers) rather than from cases collected pretreatment (less than 14 days after diagnosis, n = 1384) (P = .002). These data suggest that PPM1D variants in EOC cases are primarily somatic mosaic mutations caused by treatment and are not associated with germline predisposition to EOC.

Zauber P, Marotta S, Sabbath-Solitare M
Colorectal Cancers with the Uncommon Findings of KRAS Mutation and Microsatellite Instability.
Cytogenet Genome Res. 2015; 146(4):261-7 [PubMed] Related Publications
Sporadic colorectal cancers with microsatellite instability (MSI) frequently contain a mutation of the BRAF gene. Additionally, it has been shown that BRAF mutations in colorectal cancers are mutually exclusive of KRAS mutation. We evaluated 14 cases of colorectal cancer with MSI that were BRAF wild type but demonstrated a KRAS mutation. The codon 12/13 region in exon 2 of the KRAS oncogene and the codon 600 region in exon 15 of the BRAF gene were analyzed with standard PCR methods. MSI was evaluated by using the Bethesda panel of markers. The methylation status of the mismatch repair system was ascertained using the SALSA(®) MS-MLPA(®) methylation-specific DNA detection. The mismatch repair proteins MLH1, MSH2, MSH6, and PMS2 were evaluated by immunohistochemical staining. A total of 530 colorectal cancers were studied for MSI and KRAS gene mutation. Fourteen (2.6%) cancers with both MSI and a KRAS mutation were identified, and all cancers were BRAF wild type. Methylation was present in 7 (50%), 5 demonstrated methylation of MLH1, 1 showed methylation of MGMT, and 1 showed methylation of MSH2. Four patients had simultaneous cancers, some of which showed different genetic changes. Immunohistochemical staining suggested a germ line mutation for 4 of 10 cases with complete staining information. KRAS mutation may occur with MSI in colorectal cancers with wild-type BRAF. If a mutation in KRAS co-exists with MSI, then strong methylation of the MLH1 gene is unlikely. These tumors demonstrate that a small number of colorectal cancers will develop with atypical patterns of molecular genetic changes, suggesting that a specific pattern of genetic changes may not be as crucial as the overall accumulation of changes, consistent with the 'unique tumor principle'.

Cheng P, Wang YF, Li G, et al.
Interplay between menin and Dnmt1 reversibly regulates pancreatic cancer cell growth downstream of the Hedgehog signaling pathway.
Cancer Lett. 2016; 370(1):136-44 [PubMed] Related Publications
Menin, the product of the Men1 gene, which is frequently mutated in pancreatic neuroendocrine tumors, acts as a chromatin-remodeling factor to modulate the transcription of cell cycle regulators by interacting with histone modification factors. However, the function of menin and its underlying mechanisms in pancreatic ductal adenocarcinoma remain unknown. Here, we found that menin inhibited pancreatic cancer cell growth in vitro and in vivo and that its expression was gradually lost during pancreatic carcinogenesis. Menin overexpression significantly activated the expression of the cyclin-dependent kinase (CDK) inhibitors p18 and p27, accompanied with a decrease in DNA methylation levels of p18 and p27 promoters. Mechanistically, we found that interaction of menin with DNA methyltransferase 1 (Dnmt1) competitively pulled down Dnmt1 from p18 and p27 promoters, leading to the downregulation of DNA methylation levels. Moreover, menin expression was suppressed by Dnmt1 downstream of the Hedgehog signaling pathway, and menin overexpression strongly antagonized the promotion effect of hedgehog signaling on pancreatic cancer cell proliferation. Taken together, the interaction between menin and Dnmt1 reversibly regulates pancreatic cancer cell growth downstream of Hedgehog pathways with complex mutual modulation networks, suggesting that the Hedgehog/Dnmt1/menin axis is a potential molecular target for pancreatic cancer therapy.

Fisel P, Stühler V, Bedke J, et al.
MCT4 surpasses the prognostic relevance of the ancillary protein CD147 in clear cell renal cell carcinoma.
Oncotarget. 2015; 6(31):30615-27 [PubMed] Free Access to Full Article Related Publications
UNLABELLED: Cluster of differentiation 147 (CD147/BSG) is a transmembrane glycoprotein mediating oncogenic processes partly through its role as binding partner for monocarboxylate transporter MCT4/SLC16A3. As demonstrated for MCT4, CD147 is proposed to be associated with progression in clear cell renal cell carcinoma (ccRCC). In this study, we evaluated the prognostic relevance of CD147 in comparison to MCT4/SLC16A3 expression and DNA methylation.
METHODS: CD147 protein expression was assessed in two independent ccRCC-cohorts (n = 186, n = 59) by immunohistochemical staining of tissue microarrays and subsequent manual as well as automated software-supported scoring (Tissue Studio, Definien sAG). Epigenetic regulation of CD147 was investigated using RNAseq and DNA methylation data of The Cancer Genome Atlas. These results were validated in our cohort. Relevance of prognostic models for cancer-specific survival, comprising CD147 and MCT4 expression or SLC16A3 DNA methylation, was compared using chi-square statistics.
RESULTS: CD147 protein expression generated with Tissue Studio correlated significantly with those from manual scoring (P < 0.0001, rS = 0.85), indicating feasibility of software-based evaluation exemplarily for the membrane protein CD147 in ccRCC. Association of CD147 expression with patient outcome differed between cohorts. DNA methylation in the CD147/BSG promoter was not associated with expression. Comparison of prognostic relevance of CD147/BSG and MCT4/SLC16A3, showed higher significance for MCT4 expression and superior prognostic power for DNA methylation at specific CpG-sites in the SLC16A3 promoter (e.g. CD147 protein: P = 0.7780,Harrell's c-index = 53.7% vs. DNA methylation: P = 0.0076, Harrell's c-index = 80.0%).
CONCLUSIONS: Prognostic significance of CD147 protein expression could not surpass that of MCT4, especially of SLC16A3 DNA methylation, corroborating the role of MCT4 as prognostic biomarker for ccRCC.

Lin H, Jackson GA, Lu Y, et al.
Inhibition of Gli/hedgehog signaling in prostate cancer cells by "cancer bush" Sutherlandia frutescens extract.
Cell Biol Int. 2016; 40(2):131-42 [PubMed] Free Access to Full Article Related Publications
Sutherlandia frutescens is a medicinal plant, traditionally used to treat various types of human diseases, including cancer. Previous studies of several botanicals link suppression of prostate cancer growth with inhibition of the Gli/hedgehog (Gli/Hh) signaling pathway. Here we hypothesized the anti-cancer effect of S. frutescens was linked to its inhibition of the Gli/Hh signaling in prostate cancer. We found a dose- and time-dependent growth inhibition in human prostate cancer cells, PC3 and LNCaP, and mouse prostate cancer cell, TRAMP-C2, treated with S. frutescens methanol extract (SLE). We also observed a dose-dependent inhibition of the Gli-reporter activity in Shh Light II and TRAMP-C2QGli cells treated with SLE. In addition, SLE can inhibit Gli/Hh signaling by blocking Gli1 and Ptched1 gene expression in the presence of a Gli/Hh signaling agonist (SAG). A diet supplemented with S. frutescens suppressed the formation of poorly differentiated carcinoma in prostates of TRAMP mice. Finally, we found Sutherlandioside D was the most potent compound in the crude extract that could suppress Gli-reporter in Shh Light II cells. Together, this suggests that the S. frutescens extract may exert anti-cancer effect by targeting Gli/Hh signaling, and Sutherlandioside D is one of the active compounds.

Ramus SJ, Song H, Dicks E, et al.
Germline Mutations in the BRIP1, BARD1, PALB2, and NBN Genes in Women With Ovarian Cancer.
J Natl Cancer Inst. 2015; 107(11) [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy, responsible for 13 000 deaths per year in the United States. Risk prediction based on identifying germline mutations in ovarian cancer susceptibility genes could have a clinically significant impact on reducing disease mortality.
METHODS: Next generation sequencing was used to identify germline mutations in the coding regions of four candidate susceptibility genes-BRIP1, BARD1, PALB2 and NBN-in 3236 invasive EOC case patients and 3431 control patients of European origin, and in 2000 unaffected high-risk women from a clinical screening trial of ovarian cancer (UKFOCSS). For each gene, we estimated the prevalence and EOC risks and evaluated associations between germline variant status and clinical and epidemiological risk factor information. All statistical tests were two-sided.
RESULTS: We found an increased frequency of deleterious mutations in BRIP1 in case patients (0.9%) and in the UKFOCSS participants (0.6%) compared with control patients (0.09%) (P = 1 x 10(-4) and 8 x 10(-4), respectively), but no differences for BARD1 (P = .39), NBN1 ( P = .61), or PALB2 (P = .08). There was also a difference in the frequency of rare missense variants in BRIP1 between case patients and control patients (P = 5.5 x 10(-4)). The relative risks associated with BRIP1 mutations were 11.22 for invasive EOC (95% confidence interval [CI] = 3.22 to 34.10, P = 1 x 10(-4)) and 14.09 for high-grade serous disease (95% CI = 4.04 to 45.02, P = 2 x 10(-5)). Segregation analysis in families estimated the average relative risks in BRIP1 mutation carriers compared with the general population to be 3.41 (95% CI = 2.12 to 5.54, P = 7×10(-7)).
CONCLUSIONS: Deleterious germline mutations in BRIP1 are associated with a moderate increase in EOC risk. These data have clinical implications for risk prediction and prevention approaches for ovarian cancer and emphasize the critical need for risk estimates based on very large sample sizes before genes of moderate penetrance have clinical utility in cancer prevention.

Torabi K, Miró R, Fernández-Jiménez N, et al.
Patterns of somatic uniparental disomy identify novel tumor suppressor genes in colorectal cancer.
Carcinogenesis. 2015; 36(10):1103-10 [PubMed] Free Access to Full Article Related Publications
Colorectal cancer (CRC) is characterized by specific patterns of copy number alterations (CNAs), which helped with the identification of driver oncogenes and tumor suppressor genes (TSGs). More recently, the usage of single nucleotide polymorphism arrays provided information of copy number neutral loss of heterozygosity, thus suggesting the occurrence of somatic uniparental disomy (UPD) and uniparental polysomy (UPP) events. The aim of this study is to establish an integrative profiling of recurrent UPDs/UPPs and CNAs in sporadic CRC. Our results indicate that regions showing high frequencies of UPD/UPP mostly coincide with regions typically involved in genomic losses. Among them, chromosome arms 3p, 5q, 9q, 10q, 14q, 17p, 17q, 20p, 21q and 22q preferentially showed UPDs/UPPs over genomic losses suggesting that tumor cells must maintain the disomic state of certain genes to favor cellular fitness. A meta-analysis using over 300 samples from The Cancer Genome Atlas confirmed our findings. Several regions affected by recurrent UPDs/UPPs contain well-known TSGs, as well as novel candidates such as ARID1A, DLC1, TCF7L2 and DMBT1. In addition, VCAN, FLT4, SFRP1 and GAS7 were also frequently involved in regions of UPD/UPP and displayed high levels of methylation. Finally, sequencing and fluorescence in situ hybridization analysis of the gene APC underlined that a somatic UPD event might represent the second hit to achieve biallelic inactivation of this TSG in colorectal tumors. In summary, our data define a profile of somatic UPDs/UPPs in sporadic CRC and highlights the importance of these events as a mechanism to achieve the inactivation of TSGs.

Gorukmez O, Sag ŞO, Gorukmez Ö, et al.
Association of the ACE I/D gene polymorphisms with JAK2V617F-positive polycythemia vera and essential thrombocythemia.
Genet Test Mol Biomarkers. 2015; 19(6):303-8 [PubMed] Related Publications
The renin-angiotensin system contributes to cell growth, proliferation, and differentiation in the bone marrow. We investigated the role of the ACE I/D gene polymorphism in 108 polycythemia vera (PV) and essential thrombocytosis (ET) patients who were positive for the JAK2V617F mutation, with a thrombosis group (TG) of 95 patients who had a history of vascular events, but did not have a history of myeloproliferative neoplasms and compared these to a healthy control group (CG) of 72 subjects. In the patients, II genotype and I allele frequency (p=0.009, odds ratio [OR]=9.716, 95% confidence interval [CI]=1.242-76.00, p=0.004, OR=2.019, 95% CI=1.243-3.280, respectively) were found to be higher than those in the controls. The DD genotype (p=0.021, OR=0.491, 95% CI=0.268-0.899) and D allele (p=0.004, OR=0.495, 95% CI=0.305-0.805) were found to be correlated with a decreased risk of a myeloproliferative neoplasm. These findings support the hypothesis that the ACE II genotype and I allele may be related to increased risk of ET and PV. Conversely, the DD genotype and D allele may be related to decreased risk of ET and PV. The results also indicated that the ACE I/D gene polymorphism was independent of thrombosis formation.

Zauber P, Denehy TR, Taylor RR, et al.
Strong correlation between molecular changes in endometrial carcinomas and concomitant hyperplasia.
Int J Gynecol Cancer. 2015; 25(5):863-8 [PubMed] Related Publications
OBJECTIVE: Endometrial cancer (EC) results from the accumulation of numerous genetic abnormalities contributing to the progression from hyperplasia to EC. Information on these various genetic changes has been primarily derived from studying groups of either hyperplasias or cancers.We evaluated both hyperplastic and EC tissue obtained from the same surgical specimens for KRAS mutations, microsatellite instability (MSI), and mismatch repair gene methylation, and results were correlated between the paired hyperplastic tissue and EC. The aim was to determine if molecular alterations appearing in ECs might also be present in the premalignant (hyperplastic) region of the tumor.
METHODS: One hundred ninety-seven cases of EC with associated hyperplasia were evaluated. DNA samples were studied using primer sets for KRAS gene codons 12/13 and for MSI utilizing the Bethesda panel. Methylation testing was performed on specimens that were microsatellite unstable using the MRC Holland SALSA MS-MLPA methylation-specific DNA detection kit.
RESULTS: Forty-one (20.8%) of 197 cancers demonstrated a KRAS mutation, with 35 (85.4%) of 41 accompanying hyperplasias also containing a KRAS mutation. Forty-five cancers (22.8%) were microsatellite unstable, with 38 (84.4%) of 45 accompanying hyperplasias also demonstrating instability. Of the 45 microsatellite unstable cancers, 28 (62.2%) demonstrated methylation in both the cancer and the accompanying hyperplasia, whereas 9 pairs (20%) showed no methylation for either the cancer or hyperplasia.
CONCLUSIONS: Approximately 95% of endometrial specimens demonstrated identical molecular findings regarding KRAS mutation and microsatellite stability in the paired cancer and hyperplastic tissue. The same methylation pattern was found in 82.2% of the studied paired samples. Our findings strongly suggest that the molecular changes of KRAS mutation, MSI, and methylation occur early in the neoplastic process. We propose that endometrial biopsies revealing only hyperplasia should be studied for these molecular alterations as an indicator of possible early carcinogenesis.

Sag SO, Gorukmez O, Ture M, et al.
MMP2 gene-735 C/T and MMP9 gene -1562 C/T polymorphisms in JAK2V617F positive myeloproliferative disorders.
Asian Pac J Cancer Prev. 2015; 16(2):443-9 [PubMed] Related Publications
BACKGROUND: Myeloproliferative disorders (MPDs) are clonal hematologic malignancies originating at the level of the pluripotent hematopoietic stem cell. Matrix metalloproteases (MMPs) are proteolytic enzymes that contribute to all stages of malignancy progression. Genetic variants in the MMP genes may influence the biological function of these enzymes and change their role in carcinogenesis and progression. To our knowledge, this is the first investigation of associations between the -735 C/T and -1562 C/T polymorphisms in the MMP2 and MMP9 genes, respectively, and the risk of essential thrombocytosis (ET), and polycythemia vera (PV).
MATERIALS AND METHODS: The case-control study included JAK2V617F mutation positive 102 ET and PV patients and 111 controls. Polymorphisms were determined by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and electrophoresis.
RESULTS: No statistically significant differences were detected between patient (ET+PV) and control groups regarding genotype distribution for MMP2 gene-735 C/T and MMP9 gene -1562 C/T polymorphisms and C/T allele frequency (p>0.050). Statistically borderline significance was observed between PV and control groups regarding genotype distribution for the MMP9 gene -1562 C/T polymorphism (p=0.050, OR=2.26, 95%Cl=0.99-5.16).
CONCLUSIONS: Consequently this study supported that CC genotype of MMP9 gene -1562 C/T polymorphism may be related with PV even if with borderline significance.

Cekic C, Day YJ, Sag D, Linden J
Myeloid expression of adenosine A2A receptor suppresses T and NK cell responses in the solid tumor microenvironment.
Cancer Res. 2014; 74(24):7250-9 [PubMed] Free Access to Full Article Related Publications
High concentrations of adenosine in tumor microenvironments inhibit antitumor cytotoxic lymphocyte responses. Although T cells express inhibitory adenosine A2A receptors (A2AR) that suppress their activation and inhibit immune killing of tumors, a role for myeloid cell A2ARs in suppressing the immune response to tumors has yet to be investigated. In this study, we show that the growth of transplanted syngeneic B16F10 melanoma or Lewis lung carcinoma cells is slowed in Adora2a(f/f)-LysMCre(+/-) mice, which selectively lack myeloid A2ARs. Reduced melanoma growth is associated with significant increases in MHCII and IL12 expression in tumor-associated macrophages and with >90% reductions in IL10 expression in tumor-associated macrophages, dendritic cells (DC), and Ly6C(+) or Ly6G(+) myeloid-derived suppressor cells (MDSC). Myeloid deletion of A2ARs significantly increases CD44 expression on tumor-associated T cells and natural killer (NK) cells. Depletion of CD8(+) T cells or NK cells in tumor-bearing mice indicates that both cell types initially contribute to slowing melanoma growth in mice lacking myeloid A2A receptors, but tumor suppression mediated by CD8(+) T cells is more persistent. Myeloid-selective A2AR deletion significantly reduces lung metastasis of melanomas that express luciferase (for in vivo tracking) and ovalbumin (as a model antigen). Reduced metastasis is associated with increased numbers and activation of NK cells and antigen-specific CD8(+) T cells in lung infiltrates. Overall, the findings indicate that myeloid cell A2ARs have direct myelosuppressive effects that indirectly contribute to the suppression of T cells and NK cells in primary and metastatic tumor microenvironments. The results indicate that tumor-associated myeloid cells, including macrophages, DCs, and MDSCs all express immunosuppressive A2ARs that are potential targets of adenosine receptor blockers to enhance immune killing of tumors.

Coppola D, Balducci L, Chen DT, et al.
Senescence-associated-gene signature identifies genes linked to age, prognosis, and progression of human gliomas.
J Geriatr Oncol. 2014; 5(4):389-99 [PubMed] Related Publications
BACKGROUND: Senescence-associated genes (SAGs) are responsible for the senescence-associated secretory phenotype, linked in turn to cellular aging, the aging brain, and the pathogenesis of cancer.
OBJECTIVE: We hypothesized that senescence-associated genes are overexpressed in older patients, in higher grades of glioma, and portend a poor prognosis.
METHODS: Forty-seven gliomas were arrayed on a custom version of the Affymetrix HG-U133+2.0 GeneChip, for expression of fourteen senescence-associated genes: CCL2, CCL7, CDKN1A, COPG, CSF2RB, CXCL1, ICAM-1, IGFBP-3, IL-6, IL-8, SAA4, TNFRSF-11B, TNFSF-11 and TP53. A combined "senescence score" was generated using principal component analysis to measure the combined effect of the senescence-associated gene signature.
RESULTS: An elevated senescence score correlated with older age (r=0.37; P=.01) as well as a higher degree of malignancy, as determined by WHO, histological grade (r=0.49; P<.001). There was a mild association with poor prognosis (P=.06). Gliosarcomas showed the highest scores. Six genes independently correlated with either age (IL-6, TNFRSF-11B, IGFBP-3, SAA4, and COPG), prognosis (IL-6, SAA4), or the grade of the glioma (IL-6, IL-8, ICAM-1, IGFBP-3, and COPG).
CONCLUSION: We report: 1) a novel molecular signature in human gliomas, based on cellular senescence, translating the concept of SAG to human cancer; 2) the senescence signature is composed of genes central to the pathogenesis of gliomas, defining a novel, aggressive subtype of glioma; and 3) these genes provide prognostic biomarkers, as well as targets, for drug discovery and immunotherapy.

Higashi K, Asano K, Yagi M, et al.
Expression of the clustered NeuAcα2-3Galβ O-glycan determines the cell differentiation state of the cells.
J Biol Chem. 2014; 289(37):25833-43 [PubMed] Free Access to Full Article Related Publications
Human embryonic stem cells (hESCs) are pluripotent stem cells from early embryos, and their self-renewal capacity depends on the sustained expression of hESC-specific molecules and the suppressed expression of differentiation-associated genes. To discover novel molecules expressed on hESCs, we generated a panel of monoclonal antibodies against undifferentiated hESCs and evaluated their ability to mark cancer cells, as well as hESCs. MAb7 recognized undifferentiated hESCs and showed a diffuse band with molecular mass of >239 kDa in the lysates of hESCs. Although some amniotic epithelial cells expressed MAb7 antigen, its expression was barely detected in normal human keratinocytes, fibroblasts, or endothelial cells. The expression of MAb7 antigen was observed only in pancreatic and gastric cancer cells, and its levels were elevated in metastatic and poorly differentiated cancer cell lines. Analyses of MAb7 antigen suggested that the clustered NeuAcα2-3Galβ O-linked oligosaccharides on DMBT1 (deleted in malignant brain tumors 1) were critical for MAb7 binding in cancer cells. Although features of MAb7 epitope were similar with those of TRA-1-60, distribution of MAb7 antigen in cancer cells was different from that of TRA-1-60 antigen. Exposure of a histone deacetylase inhibitor to differentiated gastric cancer MKN74 cells evoked the expression of MAb7 antigen, whereas DMBT1 expression remained unchanged. Cell sorting followed by DNA microarray analyses identified the down-regulated genes responsible for the biosynthesis of MAb7 antigen in MKN74 cells. In addition, treatment of metastatic pancreatic cancer cells with MAb7 significantly abrogated the adhesion to endothelial cells. These results raised the possibility that MAb7 epitope is a novel marker for undifferentiated cells such as hESCs and cancer stem-like cells and plays a possible role in the undifferentiated cells.

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