Project description:Appetite is frequently affected in cancer patients, leading to anorexia and consequently insufficient food intake. In this study, we report on hypothalamic gene expression profile of a cancer cachectic mouse model with increased food intake. In this model, mice bearing C26 colon adenocarcinoma have an increased food intake subsequently to the loss of body weight. We hypothesize that in this model, appetite regulating systems in the hypothalamus, which apparently fail in anorexia, are still able to adapt adequately to changes in energy balance. Therefore studying the changes that occur on appetite regulators in the hypothalamus might reveal targets for treatment of cancer-induced eating disorders. By applying transcriptomics, many appetite regulating systems in the hypothalamus could be taken into account, providing an overview of changes that occur in the hypothalamus during tumour growth. We show that hypothalamic expression of orexigenic neuropeptides NPY and AgRP was higher, whereas expression of anorexigenic genes CCK and POMC were lower in TB compared to controls. In addition, serotonin and dopamine signalling pathways were found to be significantly altered in TB mice. Serotonin levels in brain showed to be lower in TB mice compared to control mice, while dopamine levels did not change. Moreover, serotonin levels inversely correlated with food intake. Transcriptomic analysis of the hypothalamus of cachectic TB mice with an increased food intake showed changes in NPY, AgRP and serotonin signalling. Serotonin levels in the brain showed to correlate with changes in food intake. Targeting these systems seems a promising strategy to avoid the development of cancer-induced eating disorders. C26-colon adenocarcinoma cells were subcutaneously inoculated in CDF1 mice. After 20 days, hypothalami were dissected and subjected to gene expression profiling. The total dataset consists of 2 parts; dataset 1, a pilot stuy in which mice were injected with increasing number of tumour cells and pooled samples were arrayed; and dataset 2, the main study in which mice were injected with 1 million tumour cells and samples were individually arrayed.

Project description:It has been recently shown that N-ras plays a preferential role in immune cell development and function; specifically: N-ras, but not H-ras or K-ras, could be activated at and signal from the Golgi membrane of immune cells following a low level TCR stimulus. The goal of our studies was to test the hypothesis that N-ras and H-ras played distinct roles in immune cells at the level of the transcriptome. First, we showed via mRNA expression profiling that there were over four hundred genes that were uniquely differentially regulated either by N-ras or H-ras, which provided strong evidence in favor of the hypothesis that N-ras and H-ras have distinct functions in immune cells. We next characterized the genes that were differentially regulated by N-ras in T cells following a low-level TCR stimulus. Of the large pool of candidate genes that were differentially regulated by N-ras downstream of TCR ligation, four genes were verified in qRT-PCR-based validation experiments as being differentially regulated by N-ras (Dntt, Slc9a6, Chst1, and Lars2). Finally, although there was little overlap between individual genes that were regulated by N-ras in unstimulated thymocytes and stimulated CD4+ T-cells, there was a nearly complete correspondence between the signaling pathways that were regulated by N-ras in these two immune cell types. Since we were interested primarily in genes that were differentially regulated by N-ras following a low-level TCR stimulus, our microarray data comparison was between data from TCR-stimulated, WT CD4+ T-cells and from TCR-stimulated, N-ras KO CD4+ T-cells. Genes that were differentially regulated in the comparison between stimulated N-ras KO CD4+ T-cells and unstimulated N-ras KO CD4+ T-cells, as well as those genes that were differentially regulated in the comparison between stimulated WT CD4+ T-cells and unstimulated WT CD4+ T-cells were excluded from this analysis. To determine if N-ras and H-ras regulate different sets of genes in thymocytes, a comparison was made between the set of genes that were differentially regulated by N-ras in the [WT] vs. [N-ras KO] comparison and the set of genes that were differentially regulated by H-ras in the [WT] vs. [H-ras KO] comparison. RNA was extracted from CD4+ T cell splenocytes isolated from 6-20 week old N-Ras KO and WT mice following growth in T cell growth media either with or without 1 microgram/milliliter ant-CD3 and anti-CD28 antibodies. RNA was extracted from thymocytes isolated directly from 6-20 week old N-Ras KO, H-Ras KO and WT mice.

Dataset Information

Transcription profiling of mouse anorexia-cachexia syndrome in anx/anx mouse model

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure