Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA262502 | ENA |
REPOSITORIES: ENA
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Project description:Dicer is a key endoribonuclease of the microRNA biogenetic machinery. Downregulation of Dicer has been associated with aberrant expression of microRNAs and the promotion of tumorigenesis. Calcitriol, the hormonal form of vitamin D3, increases microRNA expression in tumor cells, but the mechanism is not yet understood. Given the essential role of Dicer in microRNAs biogenesis, the purpose of this study was to evaluate whether this gene is a target for calcitriol and to explore the effects of this hormone on microRNA expression. Our findings demonstrate that calcitriol increased Dicer mRNA and protein in SiHa and HeLa cervical cancer cells, which expressed the vitamin D receptor. The inductive effect of calcitriol on Dicer mRNA was not observed in C33-A cells lacking this nuclear receptor. To explore the potential effect of Dicer upregulation by calcitriol on microRNA processing, we performed a microRNA profiling study in SiHa cells treated with calcitriol. The analysis of microRNA expression revealed that this hormone promotes the maturation of a subset of microRNAs with potential regulatory function in cancer pathways. Among these, miR-22 and miR-296-3p have already been associated with tumor-supressive effects. Our results suggest that Dicer upregulation by calcitriol could be associated, at least in part, with an increase in the maturation of a subset of tumor-suppressor microRNAs in cervical cancer cells.
2014-11-30 | GSE61829 | GEO
Project description:Background: Breast cancer patients present lower 1,25(OH)2D3 or 25(OH)D3 serum levels than unaffected women. Although 1,25(OH)2D3 pharmacological concentrations of 1,25(OH)2D3 may exert antiproliferative effects in breast cancer cell lines, much uncertainty remains about the effects of calcitriol supplementation in tumor specimens in vivo. We have evaluated tumor dimension (ultrassonography), proliferative index (Ki67 expression), 25(OH)D3 serum concentration and gene expression profile, before and after a short term calcitriol supplementation (dose to prevent osteoporosis) to post-menopausal patients. Results: Thirty three patients with operable disease had tumor samples evaluated. Most of them (87.5%) presented 25(OH)D3 insufficiency (<30 ng/mL). Median period of calcitriol supplementation was 30 days. Although tumor dimension did not vary, Ki67 immunoexpression decreased after supplementation. Transcriptional analysis of 15 matched pre/post-supplementation samples using U133 Plus 2.0 GeneChip (Affymetrix) revealed 18 genes over-expressed in post-supplementation tumors. As a technical validation procedure, expression of four genes was also determined by RT-qPCR and a direct correlation was observed between both methods (microarray vs PCR). To further explore the effects of near physiological concentrations of calcitriol on breast cancer samples, an ex vivo model of fresh tumor slices was utilized. Tumor samples from another 12 post-menopausal patients were sliced and treated in vitro with slightly high concentrations of calcitriol (0.5nM), that can be attained in vivo, for 24 hours In this model, expression of PBEF1, EGR1, ATF3, FOS and RGS1 was not induced after a short exposure to calcitriol. Conclusions: In our work, most post-menopausal breast cancer patients presented at least 25(OH)D3 insufficiency. In these patients, a short period of calcitriol supplementation may prevent tumor growth and reduce Ki67 expression, probably associated with discrete transcriptional changes. This observation deserves further investigation to better clarify calcitriol effects in tumor behavior under physiological conditions. Post-menopausal patients with early stage breast cancer, in the absence of distant metastasis, were invited to take part in the study. This protocol was approved by the Institutional Ethics Committee, and a written informed consent was signed by all participants. Patients had blood and tumor samples collected during biopsy, and were prescribed calcitriol supplementation, (Rocaltrol)TM 0.50 g/day PO, as recommended for osteoporosis prevention. Tumor specimens obtained during biopsy (pre-supplementation) or breast surgery (post-supplementation) were hand dissected and samples with at least 70% tumor cells were further processed. Breast surgery followed in about one month
2012-02-18 | E-GEOD-35925 | biostudies-arrayexpress
Project description:Background: Breast cancer patients present lower 1,25(OH)2D3 or 25(OH)D3 serum levels than unaffected women. Although 1,25(OH)2D3 pharmacological concentrations of 1,25(OH)2D3 may exert antiproliferative effects in breast cancer cell lines, much uncertainty remains about the effects of calcitriol supplementation in tumor specimens in vivo. We have evaluated tumor dimension (ultrassonography), proliferative index (Ki67 expression), 25(OH)D3 serum concentration and gene expression profile, before and after a short term calcitriol supplementation (dose to prevent osteoporosis) to post-menopausal patients. Results: Thirty three patients with operable disease had tumor samples evaluated. Most of them (87.5%) presented 25(OH)D3 insufficiency (<30 ng/mL). Median period of calcitriol supplementation was 30 days. Although tumor dimension did not vary, Ki67 immunoexpression decreased after supplementation. Transcriptional analysis of 15 matched pre/post-supplementation samples using U133 Plus 2.0 GeneChip (Affymetrix) revealed 18 genes over-expressed in post-supplementation tumors. As a technical validation procedure, expression of four genes was also determined by RT-qPCR and a direct correlation was observed between both methods (microarray vs PCR). To further explore the effects of near physiological concentrations of calcitriol on breast cancer samples, an ex vivo model of fresh tumor slices was utilized. Tumor samples from another 12 post-menopausal patients were sliced and treated in vitro with slightly high concentrations of calcitriol (0.5nM), that can be attained in vivo, for 24 hours In this model, expression of PBEF1, EGR1, ATF3, FOS and RGS1 was not induced after a short exposure to calcitriol. Conclusions: In our work, most post-menopausal breast cancer patients presented at least 25(OH)D3 insufficiency. In these patients, a short period of calcitriol supplementation may prevent tumor growth and reduce Ki67 expression, probably associated with discrete transcriptional changes. This observation deserves further investigation to better clarify calcitriol effects in tumor behavior under physiological conditions.
2012-02-18 | GSE35925 | GEO
Project description:Induction of DISE by tumor suppressive microRNAs
| PRJNA436738 | ENA
Project description:DICER has a well-characterized role in the processing of microRNAs (miRNAs) and small interfering RNAs (siRNA) that are important for post-transcriptional gene regulation. Emerging evidence suggests that DICER also has several non-canonical functions beyond miRNA/siRNA biogenesis, for example in transcriptional gene silencing at the chromatin level, as well as in RNA degradation and maintenance of genomic integrity. We have shown that the function of DICER in germ cells is essential for normal spermatogenesis; male mice lacking DICER in postnatal male germ cells are infertile due to severe defects in haploid differentiation. To better understand the function of DICER in male germ cells, we immunoprecipitated DICER from juvenile mouse testes and performed mass spectrometric analysis to identify DICER-interacting proteins.
2020-06-03 | PXD017772 | Pride
Project description:MicroRNAs (miRNAs) are critical to proliferation, differentiation, and development. Here, we characterize gene expression in murine Dicer-null adult mesenchymal stem cell lines, a fibroblast cell type. Loss of Dicer leads to de-repression of let-7 targets at levels that exceed 10-100 fold with increases in transcription. Direct and indirect targets of this miRNA belong to a mid-gestation embryonic program that encompasses known oncofetal genes as well as oncogenes not previously associated with an embryonic state. Surprisingly, this mid-gestation program represents a distinct period that occurs between the pluripotent state of the inner cell mass at embryonic day 3.5 and the induction of let-7, upon differentiation, at embryonic day 10.5. Within this mid-gestation program, we characterize the let-7 target Nr6a1, an embryonic transcriptional repressor that regulates gene expression in adult fibroblasts following miRNA loss. In total, let-7 is required for the continual suppression of embryonic gene expression in adult cells, a mechanism that may underlie its tumor suppressive function. Three dicer heterozygotes and 3 dicer null sarcoma cell lines.
2013-04-10 | E-GEOD-44162 | biostudies-arrayexpress
Project description:MicroRNAs (miRNAs) are critical to proliferation, differentiation, and development. Here, we characterize gene expression in murine Dicer-null adult mesenchymal stem cell lines, a fibroblast cell type. Loss of Dicer leads to de-repression of let-7 targets at levels that exceed 10-100 fold with increases in transcription. Direct and indirect targets of this miRNA belong to a mid-gestation embryonic program that encompasses known oncofetal genes as well as oncogenes not previously associated with an embryonic state. Surprisingly, this mid-gestation program represents a distinct period that occurs between the pluripotent state of the inner cell mass at embryonic day 3.5 and the induction of let-7, upon differentiation, at embryonic day 10.5. Within this mid-gestation program, we characterize the let-7 target Nr6a1, an embryonic transcriptional repressor that regulates gene expression in adult fibroblasts following miRNA loss. In total, let-7 is required for the continual suppression of embryonic gene expression in adult cells, a mechanism that may underlie its tumor suppressive function. Small RNAs from adult mesenchymal stem cells (immortalized clonal lines of murine MSCs) with and without Dicer (Dicer f/f, Dicer -/-) were analyzed.
2013-04-10 | E-GEOD-44156 | biostudies-arrayexpress
Project description:MicroRNAs (miRNAs) are critical to proliferation, differentiation, and development. Here, we characterize gene expression in murine Dicer-null adult mesenchymal stem cell lines, a fibroblast cell type. Loss of Dicer leads to de-repression of let-7 targets at levels that exceed 10-100 fold with increases in transcription. Direct and indirect targets of this miRNA belong to a mid-gestation embryonic program that encompasses known oncofetal genes as well as oncogenes not previously associated with an embryonic state. Surprisingly, this mid-gestation program represents a distinct period that occurs between the pluripotent state of the inner cell mass at embryonic day 3.5 and the induction of let-7, upon differentiation, at embryonic day 10.5. Within this mid-gestation program, we characterize the let-7 target Nr6a1, an embryonic transcriptional repressor that regulates gene expression in adult fibroblasts following miRNA loss. In total, let-7 is required for the continual suppression of embryonic gene expression in adult cells, a mechanism that may underlie its tumor suppressive function. Examination of histone modifications in adult mesenchymal stem cells (immortalized monoclonal lines of murine MSCs) with and without Dicer (WT: Dicer f/f, KO: Dicer -/-).
2013-04-10 | E-GEOD-44159 | biostudies-arrayexpress
Project description:Cancer cells with a stem-like phenotype are commonly described in glioblastoma, the most common primary adult brain cancer, that are thought to be highly tumorigenic. This phenotype comprimes high self renewal capacity and resistance against chemotherapy and radiation therapy, thereby promoting tumor progression and disease relapse. Here we show for the first time that calcitriol, the hormonally active form of the “sun hormone” vitamin D3, effectively suppresses stemness properties in glioblastoma stem-like cells (GSCs), supporting the hypothesis that cal-citriol sensitizes them to additional chemotherapy. Indeed, a physiologically relevant organotypic brain slice model was used to monitor tumor growth of GSCs and the effectiveness of combined treatment with temozolomide, the current standard-of-care, and calcitriol was proven. These findings indicate that further research on applying calcitriol, a well known and safe drug, as a potential adjuvant therapy for glioblastoma is both justified and necessary.
2021-07-19 | PXD026789 | Pride
Project description:MicroRNAs (miRNAs) are critical to proliferation, differentiation, and development. Here, we characterize gene expression in murine Dicer-null adult mesenchymal stem cell lines, a fibroblast cell type. Loss of Dicer leads to de-repression of let-7 targets at levels that exceed 10-100 fold with increases in transcription. Direct and indirect targets of this miRNA belong to a mid-gestation embryonic program that encompasses known oncofetal genes as well as oncogenes not previously associated with an embryonic state. Surprisingly, this mid-gestation program represents a distinct period that occurs between the pluripotent state of the inner cell mass at embryonic day 3.5 and the induction of let-7, upon differentiation, at embryonic day 10.5. Within this mid-gestation program, we characterize the let-7 target Nr6a1, an embryonic transcriptional repressor that regulates gene expression in adult fibroblasts following miRNA loss. In total, let-7 is required for the continual suppression of embryonic gene expression in adult cells, a mechanism that may underlie its tumor suppressive function. mRNAs from Flag-HA-NR6A1-overexpressing Dicer wild-type adult mesenchymal stem cells (immortalized monoclonal lines of murine MSCs) and vector-only Dicer WT MSCs were analyzed.
2013-04-10 | E-GEOD-44158 | biostudies-arrayexpress