Array comparative genomic hybridization in sporadic and coeliac disease-related small bowel adenocarcinomas
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ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Serge Smeets
PROVIDER: E-GEOD-15470 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Purpose: Small bowel adenocarcinoma (SBA) is a rare cancer and consequently the number of clinical trials has been very limited due to the small numbers of patients. Chemotherapy regimens are currently rather arbitrarily chosen between either a colorectal (CRC) or a gastric cancer (GC) regimen. Chromosomal copy number aberrations are a hallmark of solid tumours and can be measured by array comparative genomic hybridization (aCGH). The aim of the present study is to investigate whether genome-wide copy number aberrations of SBA are more similar to CRC or GC in order to support treatment of SBA according to either regimen. Experimental Design: A total of 85 GCs, CRCs and SBAs were selected from existing in house aCGH datasets based on array quality and clinical parameters. Differences and similarities in gains and losses of the three tumor types were analyzed using supervised and unsupervised analysis. Results: Hierarchical clustering revealed substantial overlap of chromosomal copy number profiles between SBA and CRC and less overlap between SBA and GC. Chromosome 13q13.2-q31.3 is primarily gained in SBA and CRC and the strongest feature discriminating SBA from GC. Further strong discriminating copy number characteristics are aberrations at chromosomes 1p36.3-p34.3, 4p15.3-q35.2, 9p24.3-p11.1 and 17p13.3-p13.2. Conclusions: SBA is more similar to CRC than to GC, based on genome-wide copy number aberrations. These data provide molecular support for treatment of SBA according to a CRC regimen. 29 gastric adenocarcinomas on 5K or 6K BAC arrays of which 2 samples are also done on 30K oligonucleotide arrays as control samples, 29 colorectal adenocarcinomas on 5K or 6K BAC arrays of which 2 samples are also done on 30K oligonucleotide arrays as control, 27 small bowel adenocarcinomas done on 30K oligonucleotide arrays of which 2 samples are also done on 5K BAC arrays as control.
2011-06-13 | E-GEOD-23418 | biostudies-arrayexpress
Project description:Background: The molecular pathogenesis of small intestinal adenocarcinomas (SBA) is not well understood. Defining its molecular pathogenesis may lead us to better clinical interventions. Aim: to identify the molecular changes characteristic of SBA. Methods: Forty-eight SBA (thirty-three non coeliac disease (CD)-related and 15 CD-related) were characterized for chromosomal aberrations, by high resolution array comparative hybridization (aCGH), microsatellite status (MSI) and APC promoter methylation and mutation status. Furthermore, molecular alterations found in CD-related SBA were compared to non-CD related SBA. Results: Chromosomal changes were observed in 77% of the SBA. The most frequently (>10%) DNA copy number changes found were gains on 5p15.33-5p12, 7p22.3-7q11.21, 7q21.2-7q21.3, 7q22.1-7q34, 7q36.1, 7q36.3, 8q11.21-8q24.3, 9q34.11-9q34.3, 13q11-13q34, 16p13.3, 16p11.2, 19q13.2 and 20p13-20q13.33 and losses of 4p13-4q35.2, 5q15-5q21.1 and 21p11.2-21q22.11. Seven highly amplified regions on 6p21.1, 7q21.1, 8p23.1, 11p13, 16p11.2, 17q12-q21.1 and 19q13.2 were also identified. CD-related and non CD-related SBA displayed similar chromosomal aberrations. Promoter hypermethylation of the APC gene was found in 48% non CD-related and 73% CD-related SBA. No nonsense mutations were found. Last, 10% of the non CD-related SBA were MSI, whereas 43% of the CD-related SBA were MSI. Conclusions: Our study characterized specific chromosomal aberrations and amplifications involved in SBA pathogenesis. At the chromosomal level, CD-related and non CD-related SBA do not differ. The involvement of the MMR system in the pathogenesis of the CD-related SBA was larger than what has been observed in no CD-related SBA. No nonsense mutations were found in SBA, but frequent promoter methylation in CD-related SBA.
2009-10-07 | GSE15470 | GEO
Project description:Vitamin D is the strongest known natural anti-proliferative. A large number of studies in a wide spectrum of cancers, including epidemiological, in vitro and animal models, demonstrate that the active form of Vitamin D has anti-cancer benefits, affecting both progression and metastasis. Alike the role in calcium Vitamin D regulation, its anti-proliferative effect is thought to function through the Vitamin D receptor (VDR), although convincing evidence is lacking. Notwithstanding, separation of the calcemic and the anti-proliferative activity of Vitamin D analogues has been a major obstacle in developing new drugs for the treatment of cancer. The work presented attempts to unveil the molecular mechanism behind the anti-proliferative action of Vitamin D using genomic tools. For that purpose four independently developed Vitamin D sensitive/resistant MCF7 cell line pairs were collected. These unique biological replicates enabled us, both to increase the power of our study and to omit the use of Vitamin D. We deem this omission crucial since in the presence of Vitamin D only downstream genes involved in proliferation and cell cycle would be identified rather than causal resistance genes. The use of a variety of genomic techniques including expression, NMD and oligo CGH arrays reveal in the resistant cell lines the 11q13-14 as a region of DNA copy number loss and an altered expression of EGFR signaling pathway genes. Surprisingly, no genes known from calcium Vitamin D regulation were identified, nor did the VDR silencing by RNAi induce resistance to the sensitive cell lines. Keywords: comparative genomic hybridization, cell type comparision Several MCF7 breast tumor cell lines independently derived from the human breast cancer cell line, both resistant and sensitive to Vitamin D, were used. The pairs of cell lines (parental-resistant) were developed in different laboratories and using different methodologies; while some cell lines acquired resistance by long exposure to the physiological concentration of Vitamin D (100nM), others were induced to resistant by being exposed to increasing amounts of Vitamin D. A total of 4 microarray expression experiments were carried out. In all microarray experiments DNA from the Vitamin D resistant cell line was hybrizided agains DNA from the respsective sensitive/parental cell line.
2008-05-31 | E-GEOD-9887 | biostudies-arrayexpress
Project description:Bortezomib is a proteasome inhibitor used in severel different hematological malignancies. Resistance to this drug is still poorly understood. In order get more insight in the resistance mechanism, we developed several bortezomib resistant subclones of the THP-1 monocytic/macrophage cell line. On these subclones expression arrays were performed. We performed expression array three different bortezomib resistant subclones of the THP-1 cell line. The resistant subclones were spotted against the parental THP-1 wildtype cell line.
2008-06-14 | E-GEOD-11771 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series: GSE11929: Identification of a subgroup of head and neck cancers lacking numerical chromosomal aberrations GSE11931: Copy Number Alterations in HNSCC with or without Oncogene Expressing Human Papillomavirus Refer to individual Series
2009-03-11 | E-GEOD-12020 | biostudies-arrayexpress
Project description:We superimposed array comparative genomic hybridization (aCGH) data onto existing expression array profiles (GSE3892) to sift out the pivotal genes underlying the pathogenesis of a well defined series of diffuse large B-cell lymphomas (DLBCL). 280 gained and over-expressed genes were identified, located on chromosomes 1q, 3q, 7, 12p12, 18q and 21q. At the most frequently gained region the oncogene MDMX/MDM4 was concurrently over-expressed, which is a critical regulator of p53 function. In regions of frequent chromosomal loss, 36 genes were concurrently down-regulated, restricted to 6q and 15p. These putative tumor suppressor genes included PERP, MAP3K5, CCNDBP1 and β2M, and loss of 6q was associated with poor clinical outcome. Genes identified and chromosomal regions validated in an independent series of DLBCL patients. Overall design fields: Copy number profiles (array CGH) of a series of 42 Diffuse large B-cell lymphoma patient samples were analyzed a) for frequency of aberrations and b) for impact on gene expression. No duplicate samples or dye-swaps were analyzed. a) Statistical analysis of Array CGH data Calling: Areas of gains and losses and their frequencies throughout the dataset were determined from the Bluefuse ratios within the statistical package â??CGHcallâ?? (van de Wiel et al., 2007). Briefly, after smoothing outliers and median normalization, â??DNAcopyâ?? segmentation (Olshen et al., 2004) was applied within CGHcall, after which a call was assigned to each position on the genome. Within CGHcall the probabilities of the calls were determined per chromosomal arm, and a cellularity correction of 0.75 was applied to each sample because tumor cellularity in all DLBCL is estimated to be maximal 75%, taking into account all stromal, endothelial en infiltrating lymphocytes. After calling, we applied â??CGHregionsâ?? (van de Wiel and van Wieringen 2007) to determine regions of consecutive clones with highly similar calls for all samples. This dimension reduction further increases robustness and statistical power for downstream statistical analyses. Called data were used for all downstream analyses. b) Integration with expression data To integrate called array CGH data with expression array data, the array CGH and expression integration tool, ACE-it (van Wieringen et al., 2006), was used. For ACE-it analysis chromosomal amplifications were included in the gains. ACE-it uses the one-sided Wilcoxon rank sum to test which chromosomal aberrations recurrently affect RNA expression and adjust p-values for multiple testing. Only those clones were taken into account which had at least 20% (9) of the samples in one of the other calling states (gain or loss). Only genes were considered relevant with a false discovery rate of <0.1. References - Olshen AB, Venkatraman ES, Lucito R, Wigler M (2004) Circular binary segmentation for the analysis of array-based DNA copy number data. Biostatistics 5: 557-72. - van de Wiel MA, Kim KI, Vosse SJ, van Wieringen WN, Wilting SM, Ylstra B (2007) CGHcall: calling aberrations for array CGH tumor profiles. Bioinformatics 23: 892-4. - van de Wiel MA, van Wieringen WN. CGHregions: dimension reduction for array CGH data with minimal information loss. Cancer Informatics. In press 2007. - van Wieringen WN, Belien JA, Vosse SJ, Achame EM, Ylstra B (2006) ACE-it: a tool for genome-wide integration of gene dosage and RNA expression data. Bioinformatics 22: 1919-20.
2010-06-25 | E-GEOD-5138 | biostudies-arrayexpress
Project description:ABSTRACT Two major subgroups of head and neck squamous cell carcinomas (HNSCC) are currently distinguished based on etiology and pattern of genetic alterations; tumors with biologically active human papillomavirus (HPV) and tumors without. It is at present unclear whether additional genetically distinct subgroups exist within HPV-negative HNSCC. Aim of this study is to genetically classify HNSCC without HPV involvement and to correlate the genetically defined classes to tumor and patient characteristics. By means of array comparative genomic hybridization (aCGH) we determined DNA copy number variation in thirty-nine HPV-negative, but further unselected HNSCC. Unsupervised analysis of aCGH data distinguished two genetic groups in HPV-negative HNSCC, one characterized by a low level of chromosomal alterations (N=9), and another by a high level of chromosomal alterations (N=30). Absence of chromosomal aberrations was significantly associated with wild-type TP53, a low level of alcohol consumption, a female gender and a better prognosis. The tumors were negative for microsatellite instability. The discovery of this new class of HNSCC with unique genetic and clinical characteristics has important consequences for future basic and clinical studies. All DNAs are isolated from fresh frozen HNSCC specimen. All tissue specimens were microdissected to obtain at least 90% tumor DNA. All sampels are hybridized against a pool of reference DNA of normal individuals of the opposite gender.
2009-03-11 | E-GEOD-11929 | biostudies-arrayexpress
Project description:An ovarian cancer cell line study to identify possible trends between chromosomal aberrations depicted from CGH microarray profiling with expression profiling. CGH microarray profiles of a panel of ovarian cancer cell lines will be analysed and 10 cell lines with chromosomal aberrations of recurrent regions (with the strongest trend) will be taken forward for further expression array analysis to identify candidate genes. CGH microarray analyses will restrict the regions of aberrations with high resolution and accurracy, combined with expression array analysis to pinpoint candidate genes that will relate to the amplified and deleted regions. Identified candidates will allow the better understanding of mechanisms and specific pathways involved in ovarian cancer development. A collection of 31 cell lines in the laboratory will be used. CGH microarray profile analyses will be carried for all, a selection process will be used to separate the groups such as the subtypes of the cell line. An analysis program will be used to depict recurrent regions and 10 cell lines will be taken forward for further expression array analysis to identify candidate genes.
2010-10-08 | E-GEOD-12523 | biostudies-arrayexpress
Project description:Cervical cancer develops from pre-cancerous high-grade cervical intraepithelial neoplasia (CIN) lesions harbouring a transforming infection with high-risk human papillomavirus (hrHPV), which is characterised by p16INK4a overexpression. Since it takes one or more decades for these pre-cancerous lesions to progress to invasive squamous cell carcinomas (SCCs), it is obvious that they are heterogeneous in terms of duration of existence and progression risk. We performed array-based comparative genomic hybridisation (array CGH) of 46 p16INK4a immuno-positive CIN2/3 lesions to determine whether this heterogeneity is reflected in their chromosomal profiles. Chromosomal profiles of CIN2/3 lesions were related to those of invasive cervical squamous cell carcinomas (SCCs) and promoter methylation of the CADM1 gene, a tumour suppressor gene known to be functionally involved in the tumorigenic phenotype of cervical cancer cells. Frequent alterations found in CIN2/3 lesions included gains located at chromosome 1, 3, 7 and 20 and losses located at 4, 11, 16, 17 and 19. Unsupervised hierarchical clustering identified two subsets of CIN2/3 lesions, chromosomal profiles of one of which closely resembled invasive SCCs. Gains of 1, 3q and 20 were characteristic for CIN2/3 lesions with chromosomal signatures resembling carcinomas. In addition, dense promoter methylation of the CADM1 gene was significantly more frequent in these CIN2/3 lesions (p=0.004). No chromosomal alterations were detected in one p16INK4a positive and five p16INK4a negative CIN1 lesions. These findings suggest that biomarkers associated with gains at chromosomes 1, 3q and 20 are potential hallmarks of advanced p16INK4a positive CIN2/3 lesions with a high short-term risk of progression. Genomic DNA of 46 high-grade cervical lesions was hybridised to 5K CGH BAC microarrays (5K) produced at the Microarray facility of the VU Medical Center. In total 4632 BAC clones with known chromosomal location were spotted in triplicate, which included the 1Mb resolution Sanger BAC clone set and a subset of clones from the Children’s Hospital Oakland Research Institute (CHORI). All samples were labelled with Cy3 and hybridised together with a pool of normal male reference DNA labelled with Cy5. Hybridisations were essentially performed as described by Snijders et al (Nature Genetics 2001). Both pre-hybridisation and hybridisation were performed in a hybridisation station (HybStation12 – Perkin Elmer Life Sciences). Hybridised arrays were scanned using a G2505B scanner (Agilent, Wilmington, DE, USA). Spots were quantified using ImaGene 5.6.1 software (BioDiscovery Ltd, Marina del Rey, CA, USA) with default settings for the flagging of bad quality spots. Genomic DNA of 6 CIN1 lesions was hybridised on CGH oligo microarrays (44K) produced by Agilent following the manufacturer’s protocol against the same normal reference pool. Hybridised arrays were scanned using the same scanner (G2505B, Agilent). Quantification of these arrays was done using Feature Extraction software version 9.5.1 (Agilent).
2009-02-19 | E-GEOD-11573 | biostudies-arrayexpress
Project description:Therapeutic screening of potential anticancer agents relies on representative cancer models. In vitro cell culture models have been long questioned to be representative for human malignant glioma. Therefore, in the present study genomic profiles of both short-term (2 weeks; n=8) and long-term (6 and 12 weeks; n=3) primary cell cultures and spheroid cultures were compared with their parental malignant gliomas. Cancer genomic profiles were obtained by 6400 BAC array comparative genomic hybridization. In 7 out of 8 short-term primary cell cultures, the genomic profiles clustered further from their parental tumors than the spheroid cultures. In 4 out of 8 samples, the changes were substantial and included chromosomal regions associated with prognosis and therapeutic response. The average correlation coefficients between parental tumor profiles and spheroid profiles was 0.89 (range: 0.79 to 0.97), whereas those between parental tumors and cell cultures was 0.62 (range: 0.10 to 0.96). In 2 out of 3 primary cell cultures progressive genetic changes appeared at 6 and 12 weeks after initial preservation, whereas the spheroid cultures were genetically stable throughout. It is concluded that the cancer genomic profile of primary cell cultures from malignant glioma is inconsistent with the parental tumorâs profile already after 2 weeks with subsequent progressive genetic changes. Because malignant glioma spheroids are genetically stable, biological characteristics of the parental tumor are better reflected. This indicates that the spheroid model is better for therapeutic screening. Keywords: comparative genomic hybridization Two in vitro culture models (primary cell culture and organotypic spheroid culture) and their parental tumor were compared in whole-genome DNA copy number profile. Malignant glioma surgical specimens from 8 patients were divided in parental tumor (T), primary cell culture (C) and organotypic spheroid culture (S). After 2 weeks, genomic DNA was extracted from culture harvests. For 3 of 8 surgical specimens (patient 55, 58, 60) cultures were extended to 6 and 12 weeks to determine DNA copy number changes in time. Primary cell culture harvests at 2, 6 and 12 weeks were named C1, C2, C3 and organotypic spheroid cultures harvests at 2, 6 and 12 weeks were named S1, S2, S3.
2010-06-12 | E-GEOD-6042 | biostudies-arrayexpress