Characterization of 8p21.3 chromosomal deletions in B-cell lymphoma: TRAIL-R1 and TRAIL-R2 as candidate dosage-dependent tumor suppressor genes

Deletions of chromosome 8p are a recurrent event in B-cell non-Hodgkin lymphoma (B-NHL), suggesting the presence of a tumor suppressor gene. We have characterized these deletions using comparative genomic hybridization to microarrays, fluorescence in situ hybridization (FISH) mapping, DNA sequencing, and functional studies. A minimal deleted region (MDR) of 600 kb was defined in chromosome 8p21.3, with one mantle cell lymphoma cell line (Z138) exhibiting monoallelic deletion of 650 kb. The MDR extended from bacterial artificial chromosome (BAC) clones RP11-382J24 and RP11-109B10 and included the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor gene loci. Sequence analysis of the individual expressed genes within the MDR and DNA sequencing of the entire MDR in Z138 did not reveal any mutation. Gene expression analysis and quantitative reverse transcriptase-polymerase chain reaction (QRT-PCR) showed down-regulation of TRAIL-R1 and TRAIL-R2 receptor genes as a consistent event in B-NHL with 8p21.3 loss. Epigenetic inactivation was excluded via promoter methylation analysis. In vitro studies showed that TRAIL-induced apoptosis was dependent on TRAIL-R1 and/or -R2 dosage in most tumors. Resistance to apoptosis of cell lines with 8p21.3 deletion was reversed by restoration of TRAIL-R1 or TRAIL-R2 expression by gene transfection. Our data suggest that TRAIL-R1 and TRAIL-R2 act as dosage-dependent tumor suppressor genes whose monoallelic deletion can impair TRAIL-induced apoptosis in B-cell lymphoma

Homozygous deletions localize novel tumor suppressor genes in B-cell lymphomas

Integrative genomic and gene-expression analyses have identified amplified oncogenes in B-cell non-Hodgkin lymphoma (B-NHL), but the capability of such technologies to localize tumor suppressor genes within homozygous deletions remains unexplored. Array-based comparative genomic hybridization (CGH) and gene-expression microarray analysis of 48 cell lines derived from patients with different B-NHLs delineated 20 homozygous deletions at 7 chromosome areas, all of which contained tumor suppressor gene targets. Further investigation revealed that only a fraction of primary biopsies presented inactivation of these genes by point mutation or intragenic deletion, but instead some of them were frequently silenced by epigenetic mechanisms. Notably, the pattern of genetic and epigenetic inactivation differed among B-NHL subtypes. Thus, the P53-inducible PIG7/LITAF was silenced by homozygous deletion in primary mediastinal B-cell lymphoma and by promoter hypermethylation in germinal center lymphoma, the proapoptotic BIM gene presented homozygous deletion in mantle cell lymphoma and promoter hypermethylation in Burkitt lymphoma, the proapoptotic BH3-only NOXA was mutated and preferentially silenced in diffuse large B-cell lymphoma, and INK4c/P18 was silenced by biallelic mutation in mantle-cell lymphoma. Our microarray strategy has identified novel candidate tumor suppressor genes inactivated by genetic and epigenetic mechanisms that substantially vary among the B-NHL subtypes

The LSD1-Interacting Protein GILP Is a LITAF Domain Protein That Negatively Regulates Hypersensitive Cell Death in Arabidopsis

Hypersensitive cell death, a form of avirulent pathogen-induced programmed cell death (PCD), is one of the most efficient plant innate immunity. However, its regulatory mechanism is poorly understood. AtLSD1 is an important negative regulator of PCD and only two proteins, AtbZIP10 and AtMC1, have been reported to interact with AtLSD1.To identify a novel regulator of hypersensitive cell death, we investigate the possible role of plant LITAF domain protein GILP in hypersensitive cell death. Subcellular localization analysis showed that AtGILP is localized in the plasma membrane and its plasma membrane localization is dependent on its LITAF domain. Yeast two-hybrid and pull-down assays demonstrated that AtGILP interacts with AtLSD1. Pull-down assays showed that both the N-terminal and the C-terminal domains of AtGILP are sufficient for interactions with AtLSD1 and that the N-terminal domain of AtLSD1 is involved in the interaction with AtGILP. Real-time PCR analysis showed that AtGILP expression is up-regulated by the avirulent pathogen Pseudomonas syringae pv. tomato DC3000 avrRpt2 (Pst avrRpt2) and fumonisin B1 (FB1) that trigger PCD. Compared with wild-type plants, transgenic plants overexpressing AtGILP exhibited significantly less cell death when inoculated with Pst avrRpt2, indicating that AtGILP negatively regulates hypersensitive cell death.These results suggest that the LITAF domain protein AtGILP localizes in the plasma membrane, interacts with AtLSD1, and is involved in negatively regulating PCD. We propose that AtGILP functions as a membrane anchor, bringing other regulators of PCD, such as AtLSD1, to the plasma membrane. Human LITAF domain protein may be involved in the regulation of PCD, suggesting the evolutionarily conserved function of LITAF domain proteins in the regulation of PCD

Exon-Level Transcriptome Profiling in Murine Breast Cancer Reveals Splicing Changes Specific to Tumors with Different Metastatic Abilities

In breast cancer patients, tumor metastases at distant sites are the main cause of death. However, the molecular mechanisms of metastasis of breast cancer remain unclear. It is thought that changes occurring at the level of RNA processing contribute to cancer. Alternative splicing (AS) of pre-mRNA, a key post-transcriptional mechanism allowing for the production of distinct proteins from a single gene, affects over 90% of human genes. Such splicing events are responsible for generating mRNAs that encode protein isoforms that can have very different biological properties and functions. A well-studied example is the BCL-X gene, whose two major transcript isoforms produce two proteins having antagonistic functions: the short form (BCL-XS) promotes apoptosis while the long form (BCL-XL) is anti-apoptotic. Moreover, overexpression of BCL-XL has been reported to enhance the metastatic potential of breast tumor cells in patients

Chiral bis(amino amides) as chiral solvating agents for enantiomeric excess determination of α-hydroxy and arylpropionic acids

A family of bis(amino amides) derived from natural amino acids has been synthesized and tested for the NMR enantiodiscrimination, as chiral solvating agents, for enantiomeric excess determination of some carboxylic acids. Those bis(amino amide) receptors contain different structural modifications and the splitting of the signals of the acids, after addition of the corresponding CSAs, depends on those structural variables. The influence of aminoacid side chain and the nature of the aliphatic spacer are important parameters to obtain good chiral discriminations. The results obtained clearly show the chiral recognition abilities of these bis(amino amide) ligands and suggest their advantageous use as chiral solvating agents for carboxylic acids. The binding between bis(amino amides) and carboxylic acids has been studied by ESI-MS, NMR, DSC, and molecular modeling. The data suggest that enantiodiscrimination involves the formation of an ionic pair after proton transfer from the carboxylic substrate to the bis(amino amides). © 2010 Elsevier Ltd. All rights reserved

Reduced expression and homozygous deletion of annexin A10 in gastric carcinoma

Annexins (ANXs) are a family of calcium and phospholipid binding proteins that have been implicated in diverse important biological and physiological process. ANX AN (ANXA10) is a member of this family, though little is known about its functions. In the present study, array based comparative genomic hybridization (CGH) was used to screen DNA copy number change in gastric cancer cell lines and the results obtained were compared with oligonucleotide microarray data. DNA loss of the ANXA10 locus in chromosome 4q33 was found in several gastric cancer cell lines by array based CGH and these cell lines showed decreased ANXA10 expression by oligonucleotide microarray analysis. Functional analysis using siRNA and full-length cDNA transfection in gastric cancer cell lines demonstrated that ANXA10 regulates gastric cancer cell proliferation. Of the 585 primary gastric carcinoma tissues examined, ANXA10 expression at the protein level was found to be reduced in 289 (49.4%) cases. Quantitative real-time PCR analysis validated loss of DNA at the ANXA10 locus in gastric carcinomas with reduced ANXA10 expression. By univariate survival analysis, lack of ANXA10 expression was associated with poor survival (p = 0.016). These results suggest that ANXA10 inactivation by chromosomal deletion may play a role during gastric cancer progression. (C) 2009 UICCNakaya K, 2007, ONCOGENE, V26, P5300, DOI 10.1038/sj.onc.1210330Sato N, 2007, INT J CANCER, V120, P543, DOI 10.1002/ijc.22328Mestre-Escorihuela C, 2007, BLOOD, V109, P271, DOI 10.1182/blood-2006-06-026500Takada H, 2006, ONCOGENE, V25, P6554, DOI 10.1038/sj.onc.1209657Hsiang CH, 2006, PROSTATE, V66, P1413, DOI 10.1002/pros.20457Kang JU, 2006, J KOREAN MED SCI, V21, P656Tatenhorst L, 2006, NEUROPATH APPL NEURO, V32, P271, DOI 10.1111/j.1365-2990.2006.00720.xWu X, 2006, ONCOGENE, V25, P1832, DOI 10.1038/sj.onc.1209191Ying J, 2006, ONCOGENE, V25, P1070, DOI 10.1038/sj.onc.1209154Sterian A, 2006, ONCOLOGY-BASEL, V70, P168, DOI 10.1159/000094444Patil MA, 2005, CARCINOGENESIS, V26, P2050, DOI 10.1093/carcin/bgi178Takada H, 2005, ONCOGENE, V24, P8051, DOI 10.1038/sj.onc.1208952Hui ABY, 2005, CANCER RES, V65, P8125, DOI 10.1158/0008-5472.CAN-05-0648Peng SY, 2005, INT J ONCOL, V26, P1053Kawaguchi K, 2005, BIOCHEM BIOPH RES CO, V329, P370, DOI 10.1016/j.bbrc.2005.01.128Senchenko VN, 2004, ONCOGENE, V23, P5719, DOI 10.1038/sj.onc.1207760Leighton X, 2004, CANCER LETT, V210, P239, DOI 10.1016/j.canlet.2004.01.018Deng QD, 2004, ONCOGENE, V23, P4903, DOI 10.1038/sj.onc.1207615Kakinuma N, 2004, INT J CANCER, V109, P71, DOI 10.1002/ijc.11674Moss SE, 2004, GENOME BIOL, V5Pedrero JMG, 2004, AM J PATHOL, V164, P73Tay ST, 2003, CANCER RES, V63, P3309Veltman JA, 2003, CANCER RES, V63, P2872Senchenko V, 2003, ONCOGENE, V22, P2984, DOI 10.1038/sj.onc.1206429Hasegawa S, 2002, CANCER RES, V62, P7012Carvalho R, 2002, LAB INVEST, V82, P1319, DOI 10.1097/01.LAB.0000029205.76632.A8Liu SH, 2002, AM J PATHOL, V160, P1831Gerke V, 2002, PHYSIOL REV, V82, P331, DOI 10.1152/physrev.00030.2001Araki D, 2002, INT J ONCOL, V20, P355Srivastava M, 2001, P NATL ACAD SCI USA, V98, P4575Kim YH, 2001, AM J PATHOL, V158, P655Shivapurkar N, 1999, CANCER RES, V59, P3576Sakakura C, 1999, GENE CHROMOSOME CANC, V24, P299Boland CR, 1998, CANCER RES, V58, P5248Piao Z, 1998, INT J CANCER, V79, P356Wang SI, 1998, CLIN CANCER RES, V4, P811KALLIONIEMI A, 1992, SCIENCE, V258, P818SCHLAEPFER DD, 1990, J CELL BIOL, V111, P229