Project description:Vitamin D may have anti-tumorigenic actions by influencing the gene expression profile of target tissues, which possess vitamin D receptors. We used a more physiological in vitro model, represented by short-term culture of breast cancer tissue slices, to study the transcriptional effects of a near physiological concentration of calcitriol. Methods. Breast cancer fragments were sliced and maintained in culture for 24 hours in the presence or absence (control) of calcitriol 0.5nM or 100nM (called physiological or supra-physiological concentrations). Five and 16 samples were included in a test or validation group and gene expression was analyzed by microarray (using SAM paired analysis) or qPCR, respectively. Results. Nine genes were regulated by calcitriol 0.5nM including CYP24A1, DPP4, EFTUD1 (FDR£0.01), which were up-modulated. However, using a less stringent FDR value (0.25) 61 genes were differentially expressed. Among the down-regulated transcripts were members of the MHC class II complex (HLA-DPA1, HLA-DQA1, HLA-DQA2, HLA-DQB1, HLA-DRA, HLA-DRB1, HLA-DRB3) and IgG binding (FCGR2A, FCGR2B, FCGR2C). There was an enrichment of genes presenting transcription factor binding sites for vitamin D, among the up-regulated genes and for interferon regulatory factor IRF1, among the down-regulated genes. Analyzing calcitriol supra-physiological effects, a more impressive transcriptional modulation was identified and 136 and 60 genes (FDR 0.1) were more and less expressed in treated samples. Up-regulated genes were involved in vitamin metabolic process, regulation of leukocyte-mediated immunity and positive regulation of alpha-beta T cell activation. Many of the induced genes were already reported as vitamin D responsive genes, including CD14, which was also up-regulated in another set of 16 samples. Genes modulated by both calcitriol concentrations were CYP24A1, DPP4, CA2 (these three in both sets of samples), EFTUD1, TKTL1, KCNK3. Conclusion. Small increments in calcitriol concentration, within the physiological range, for a relatively short period of time may exert transcriptional effects in breast cancer samples. Further studies employing physiological concentrations of vitamin D for longer periods of time may help to elucidate the hormone effects in breast cancer treatment and prevention. Breast cancer fragments were sliced and maintained in culture for 24 hours in the presence or absence (control) of calcitriol 0.5nM or 100nM (called physiological or supra-physiological concentrations). Five samples were included and were categorized according to treatment in three groups: control (A), 1,25(OH)2D3 0.5nM (B) and 1,25(OH)2D3 100nM (C).Total RNA was isolated using RNeasy kit and than was carried out according to microarray Affymetrix protocol. Data was then assessed with GeneSpring X software for background correction, normalization and summarization of raw data (CEL files) using the Robust Multi-Array Average (RMA). Five samples were included in a test and gene expression was analyzed by microarray (using SAM paired analysis). To establish a differential gene expression profile between vitamin D treated and untreated samples, SAM two class paired, provided on MEV (MultiExperiment Viewer – Boston, MA, USA) was used. Unsupervised hierarchical clustering based on Euclidean distance and average linkage was used to verify association patterns. The reliability of the clustering was assessed by the Bootstrap technique using MEV (MultiExperiment Viewer – Boston, MA, USA). Samples (16) were included in a validation group and was analyzed by qPCR.

Project description:Vitamin D may have anti-tumorigenic actions by influencing the gene expression profile of target tissues, which possess vitamin D receptors. We used a more physiological in vitro model, represented by short-term culture of breast cancer tissue slices, to study the transcriptional effects of a near physiological concentration of calcitriol. Methods. Breast cancer fragments were sliced and maintained in culture for 24 hours in the presence or absence (control) of calcitriol 0.5nM or 100nM (called physiological or supra-physiological concentrations). Five and 16 samples were included in a test or validation group and gene expression was analyzed by microarray (using SAM paired analysis) or qPCR, respectively. Results. Nine genes were regulated by calcitriol 0.5nM including CYP24A1, DPP4, EFTUD1 (FDR£0.01), which were up-modulated. However, using a less stringent FDR value (0.25) 61 genes were differentially expressed. Among the down-regulated transcripts were members of the MHC class II complex (HLA-DPA1, HLA-DQA1, HLA-DQA2, HLA-DQB1, HLA-DRA, HLA-DRB1, HLA-DRB3) and IgG binding (FCGR2A, FCGR2B, FCGR2C). There was an enrichment of genes presenting transcription factor binding sites for vitamin D, among the up-regulated genes and for interferon regulatory factor IRF1, among the down-regulated genes. Analyzing calcitriol supra-physiological effects, a more impressive transcriptional modulation was identified and 136 and 60 genes (FDR 0.1) were more and less expressed in treated samples. Up-regulated genes were involved in vitamin metabolic process, regulation of leukocyte-mediated immunity and positive regulation of alpha-beta T cell activation. Many of the induced genes were already reported as vitamin D responsive genes, including CD14, which was also up-regulated in another set of 16 samples. Genes modulated by both calcitriol concentrations were CYP24A1, DPP4, CA2 (these three in both sets of samples), EFTUD1, TKTL1, KCNK3. Conclusion. Small increments in calcitriol concentration, within the physiological range, for a relatively short period of time may exert transcriptional effects in breast cancer samples. Further studies employing physiological concentrations of vitamin D for longer periods of time may help to elucidate the hormone effects in breast cancer treatment and prevention.

Project description:AIM Vitamin D deficiency is associated with risk of several common cancers, including colorectal cancer (CRC). We investigated the effects of vitamin D on in vitro and ex vivo epithelial cell gene expression and assessed dysregulation of pathways involved in anti-tumour effects. METHODS We performed in vitro and ex vivo intervention studies using established CRC cell lines and patient-derived epithelial organoids developed from normal human colonic (resectional colorectal surgery) and rectal mucosa (rectal biopsy). RNA and protein were harvested after 16-24 hours’ calcitriol treatment. Gene expression was assessed by qRT-PCR, microarray and RNA-sequencing, and protein expression by immunoblotting and mass-spectrometry. Gene Ontology enrichment analysis was performed using GOrilla and Gene Set Enrichment Analysis. RESULTS Calcitriol increased the expression of the tumour suppressor gene CDH1 in CRC cell lines (SW480; FC=3.60, 95%CI 2.17-5.03) and patient-derived epithelial cell organoids (n=6, FC=1.64, 95%CI 1.49-1.80), with associated in vitro E-cadherin protein induction. Significant differential expression of a further 6 common genes was observed on microarray analysis of in vitro and ex vivo experiments, including genes with established links to carcinogenesis GADD45, EFTUD1 and KIAA1199. Numerous ontologies relevant to carcinogenesis were enriched (e.g. ‘regulation of Wnt signaling pathway’, ‘regulation of cell death’), with common enriched processes across in vitro and ex vivo cultures including ‘negative regulation of cell proliferation’, ‘regulation of cell migration’ and ‘regulation of cell differentiation’. CONCLUSIONS We report for the first time, common genes and pathways modulated by calcitriol treatment in both in vitro and ex vivo models, with several differentially expressed genes strongly linked to CRC tumourigenesis. Enrichment of biological pathways after calcitriol treatment provides further evidence of anti-tumour effects. These findings support epidemiological data and provide strong rationale for well-designed trials of vitamin D supplementation as a novel CRC chemopreventive and chemotherapeutic agent. see above

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Calcitriol induces a distinctive transcriptional program in Chronic Lymphocytic Leukemia (CLL) cells

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