Indirect expression microarray from 5 pairs of tissues from colorectal cancer patients
ABSTRACT: 5 colorectal cancer (CRC) tissues and 5 paired non-tumor tissues from CRC patients were indirectly compared using a 17K cDNA microarray. The total RNA from each tissue was labeled with Cy5, and the total RNAs from 11 human cell lines were labeled with Cy3 as the reference.
Project description:5-aza-2'-deoxycytidine (DAC) treated and untreated Caco-2 cells were compared using an expression microarray. Total RNA from untreated Caco-2 cells was labeled with Cy3, and total RNA from DAC-treated Caco-2 cells was labeled with Cy5.
Project description:This SuperSeries is composed of the following subset Series: GSE19659: Indirect expression microarray from 5 pairs of tissues from colorectal cancer patients GSE19660: Expression microarray with 5-aza-2'-deoxycytidine-treated Caco-2 cells Refer to individual Series
Project description:Mice were fed for 6 months with a normal chow (NC) or a high fat diet (HFD). After 6 months of diet, high fat fed mice with Low, Medium and High body weight, but with similar glucose intolerance, were selected. These selected mice as well as NC mice were then treated with Rimonabant or Vehicle for 1 month. After treatment, mice were sacrificed and visceral and subcutaneous adipose tissues were collected and immediately frozen in liquid nitrogen. Total RNA from each sample was further extracted, purified, quality-controled before and after amplification, Cy5-labeled and co-hybridized with a Cy3-labeled mouse Universal Reference total RNA on the mouse 17K microarray. Keywords: diet response, pharmacological response Each individual RNA sample was hybridized with a mouse Universal Reference Total RNA
Project description:Despite identification of major genes and pathways involved in development of colorectal cancer (CRC) it became obvious that several steps in these pathways might be bypassed by other yet unknown genetic events that lead towards CRC. To improve our understanding of the genetic mechanisms of CRC development we used microarrays to identify novel genes involved in development of CRC. In order to identify possible novel genes involved in the development of colorectal cancer we analysed the expression profile of 16 colorectal cancers. We used dual color approach. Tumour tissue was labeled with Cy5 and corresponding normal tissue was labeled with Cy3. Each array contained at least 4 replicate spots for each gene analysed. Expression was obtained by calculating median from replicate spots. Genes not present in at least 100% of all samples were filtered out. Median value for each gene from 16 arrays was calculated.
Project description:Mice were fed for 2, 10 or 30 days with a normal chow (NC) or a high fat diet (HFD). At each time point, mice were sacrificed and liver samples were collected and immediately frozen in liquid nitrogen. Total RNA from each sample was further extracted, purified, quality-controled before and after amplification. Cy3-labeled RNA from individual liver sample was co-hybridized with a Cy5-labeled pool of RNA on the mouse 17K microarray. Keywords: diet response, time course, mouse strains For a given time point, each individual RNA sample was hybridized with a pool of RNA from 6 mice
Project description:Concerns have arisen recently over the possible environmental effects of human pharmaceuticals. Although acute toxicities are low, the continuous discharge of pharmaceuticals into the aquatic environment, coupled with the fact that such compounds are selected for use on the basis of a strong pharmacological effect, means that sublethal effects on non-target organisms need to be seriously considered. The juvenile stages of Atlantic salmon are present in many northern European rivers which are also used for the discharge of domestic wastewaters likely to contain pharmaceuticals. One year old salmon parr were exposed to an environmentally relevant concentration (5µg·/ L) of the antidepressant drug carbamazepine for five days and changes of mRNA expression in brain tissues were investigated by means of a custom 17k Atlantic salmon cDNA microarray. The TRAITS 17K Atlantic salmon cDNA microarray was employed. A dual-labelled experimental design was employed for the microarray hybridisations. Each experimental cDNA sample (Cy3 labeled) was competitively hybridised against a common pooled-reference sample (Cy5 labeled). The entire experiment comprised 10 hybridisations - 2 states (CBZ exposed / unexposed) × 1 time-point ( at 5 days) × 5 biological replicates (males only). Hybridisations were undertaken concurrently.
Project description:Background & Aims. The current staging system for colorectal cancer (CRC) based on TNM classification allows prediction of potential recurrence. However, it does not necessarily make reliable personalized prediction of prognosis. In this paper we describe combination of clinicopathological data and gene signature of dissected tumor specimen with stage II and III CRC patients would improve the situation.. Methods. A total of 1978 CRC were collected over 5 years, and then 371 stage II and 322 stage III of them with more than 45.9 months records were subjected to clinicopathological feature analyses. Out of this collection, 129 stage II and III CRC cases were selected for analyses of gene expression profiles with resected specimen. The gene signatures were analyzed by repeated random divisions of the samples into training and test sets to extract discriminator genes. After testing the applicability of this discriminator set, it was subjected to validation using a newly obtained set of 69 samples. Results. The pathological factors in solo or in combinations could not make personalized recurrence prediction, except for partial success with stage II patients. The gene signature, on the other hand, was capable of producing a set of discriminator genes, though the accuracy was yet to be improved. We observed that the best result was obtained when discriminators were selected from stage II CRC samples and used for prognosis of stage II CRC. When stage III cases were included in the process of discriminator extraction or in the process to validate samples, the results were poorer. Finally, we examined 31 independent stage II samples with a set of 30 such discriminators and were able to obtain results with 78 % accuracy, 90 % negative predictive value (NPV), and 55% positive predictive value (PPV). Conclusions. Independent clinicopathological variables were not able to predict prognosis of individual patient, unless the factors are combined. On the other hand, gene signatures allowed accurate prediction of prognosis for individuals, especially with stage II CRC, suggesting its potential use for selection of best treatment option for individual patients. The accuracy of discriminator prediction will be further improved when we take the evolution of CRC into consideration. Of 198 samples, 129 represented the discovery phase and 69 represented the validation phase.
Project description:To identify novel hypermethylated genes in colorectal cancer (CRC) and to test their potential application in CRC early diagnosis, we performed a genome-wide screening of 57,723 CpG dinucleotides covering 4,010 genes in paired DNA samples extracted from 3 fresh frozen CRC tissues and their matching non-tumor adjacent tissues from a cohort of 3 CRC patients undergoing curative surgery using MIRA-based microarray. We also validated candidate hypermethylated genes screened by MIRA-based microarray in independent CRC samples using combined bisulfite restriction analysis. A total of 297 CpG dinucleotides in CRC covering 211 genes were found to be hypermethylated in CRC tissues. From these 211 candidate methylated genes, seven novel methylated genes were picked up for validation and three genes were confirmed to be methylated in cancer samples but not in non-cancer samples.We also compared the methylation levels of these three novel hypermethylated genes with those of Vimentin and SEPT9, well-known hypermethylated genes in CRC, and found that methylated PHOX2B, FGF12 and GAD2 were better than methylated Vimentin and SEPT9 in differentiating CRC cancer tissue from normal tissue. Significant enrichment analysis of GO terms of the hypermethylated genes showed that a high proportion of hypermethylated genes in tumor tissues are involved in regulation of transcription. Paired experiments, colorectal cancer tissue vs. adjacent non-cancer tissue. Biological replicates: 3 cancer replicates, 3 paired non-cancer replicates.
Project description:Pharmaceuticals are pseudo persistent aquatic pollutants with unknown effects at environmentally relevant concentrations. Atlantic salmon (Salmo salar) were exposed to Acetaminophen: 54.77 ± 34.67; Atenolol: 11.08 ± 7.98 and Carbamazepine: 7.85 ± 0.13 µg•L-1 for 5 days. After Acetaminophen treatment, 19 proteins were differently expressed, of which 11 were significant with respect to the control group (eight up-regulated and three down-regulated). After Atenolol treatment, 7 differently expressed proteins were obtained in comparison with the control, of which 6 could be identified (four up-regulated and 2 down-regulated). Carbamazepine exposure resulted in 15 differently expressed proteins compared with the control, with 10 of them identified (seven up-regulated and three down-regulated). Out of these, 3 features were common between Acetaminophen and Carbamazepine and one between Carbamazepine and Atenolol. One feature was common across all treatments. Principal component analysis and heat map clustering showed a clear grouping of the variability due to the applied treatments. The obtained data suggest (1) that exposure to environmentally relevant concentrations of the pharmaceuticals alters the hepatic protein expression profile of the Atlantic salmon; and (2) the existence of treatment specific processes that may be useful for biomarker development.
Project description:Pseudomonads, unlike enteric bacteria, prefer to utilize tricarboxylic acid cycle intermediates over glucose. The crc gene has been implicated to impart repression on glucose and other metabolic enzymes in various Pseudomonas species when grown in a mixture of glucose and various organic acids. The crc gene of P. fluorescens strain MB101 has been identified and a crc deletion derivative was constructed. Unlike a crc mutant of P. aeruginosa described earlier, the P. fluorescens crc did not begin to catabolize glucose until most of the succinate has been utilized in a medium containing both carbon sources. The transition phase during diauxic growth in succinate/glucose media was found to be shorter in a strain lacking crc and considerably longer in a strain overproducing Crc as compared to the wild type. DNA microarray analyses were performed with wild-type and crc mutant strains during the transition phase from succinate to glucose. In the wild-type strain, high expression signals were obtained for genes normally induced in cells that approach or are in stationary phase. By contrast, crc cells showed higher expression signals for genes associated with rapid growth than the wild-type strain. Taken together, this data indicates that Crc influences the length of the lag during the transition phase from succinate to glucose by directly or indirectly affecting the mRNA levels of target genes. Keywords: time course strain comparison These are time course experiments to compare crc mutant strain to the wildtype MB101 strain at 5, 6, 7, 8, and 9 ht time points. Dye swaps were included in each time point comparison. There are 10 pairs in total.