Project description:To identify genes differentially modulated by anti-miR-182 treatment in a liver melanoma metastasis mouse model. Targeting oncogenic microRNAs is emerging as a promising strategy for cancer therapy. Here we provide proof-of-principle for the safety and efficacy of miRNA targeting against metastatic tumors. We tested the effect of targeting miR-182, a pro-metastatic miRNA frequently overexpressed in melanoma, whose silencing represses invasion and induces apoptosis in vitro. In particular, we assessed the effect of anti-miR-182 oligonucleotides synthesized with 2â sugar modifications and a phosphorothioate backbone in a mouse model of melanoma liver metastasis. Luciferase imaging showed that mice treated with anti-miR-182 had an appreciably lower burden of liver metastases compared to the control. We confirmed that miR-182 levels were effectively downregulated in the anti-miR treated tumors relative to the scrambled treated tumor both in the liver and in the spleen. This downregulation was accompanied by an upregulation of miR-182 direct targets. Transcriptome analysis of mouse tissues treated with anti-miR-182 or scramble oligonucleotides revealed an enrichment for genes controlling survival, adhesion and migration modulated in response to anti-miR-182 treatment. These data indicate that in vivo administration of anti-miRs allows for efficient miRNA targeting and concomitant upregulation of target levels. Our results suggest that the use of anti-miR-182 is a promising therapeutic strategy for metastatic melanoma and provide solid proof-of-principle for similar strategies against other metastatic tumors. Keywords: Differentially expressed genes (mRNAs) in response to miRNA inhibition Quadruplicate (n=4) samples of anti-miR-182 treated human melanoma metastasis compared to quadruplicate control treated metastasis.
Project description:To identify genes differentially modulated by anti-miR-182 treatment in a liver melanoma metastasis mouse model. Targeting oncogenic microRNAs is emerging as a promising strategy for cancer therapy. Here we provide proof-of-principle for the safety and efficacy of miRNA targeting against metastatic tumors. We tested the effect of targeting miR-182, a pro-metastatic miRNA frequently overexpressed in melanoma, whose silencing represses invasion and induces apoptosis in vitro. In particular, we assessed the effect of anti-miR-182 oligonucleotides synthesized with 2’ sugar modifications and a phosphorothioate backbone in a mouse model of melanoma liver metastasis. Luciferase imaging showed that mice treated with anti-miR-182 had an appreciably lower burden of liver metastases compared to the control. We confirmed that miR-182 levels were effectively downregulated in the anti-miR treated tumors relative to the scrambled treated tumor both in the liver and in the spleen. This downregulation was accompanied by an upregulation of miR-182 direct targets. Transcriptome analysis of mouse tissues treated with anti-miR-182 or scramble oligonucleotides revealed an enrichment for genes controlling survival, adhesion and migration modulated in response to anti-miR-182 treatment. These data indicate that in vivo administration of anti-miRs allows for efficient miRNA targeting and concomitant upregulation of target levels. Our results suggest that the use of anti-miR-182 is a promising therapeutic strategy for metastatic melanoma and provide solid proof-of-principle for similar strategies against other metastatic tumors. Keywords: Differentially expressed genes (mRNAs) in response to miRNA inhibition
Project description:A variety of CD4+Foxp3+ Treg cell types have been described previously, indicating molecular heterogeneity within the Foxp3+ pool of CD4+ T cells. However, the factors that shape the transcriptomic identities of different Foxp3+ Treg cells are poorly understood. To identify the molecular pathways involved, we isolated CD4+Foxp3gfp+ cells from Th1-rich or Th2-rich environments following chronic Leishmania major or Schistosoma mansoni infection, respectively. Whole genome expression profiling and next generation small RNA sequencing revealed significantly different mRNA and miRNA profiles. In-silico analyses identified miR-10a and miR-182 as âregulatory miRNA hubsâ in CD4+Foxp3+ cells in Th1 and Th2-environments, respectively. Using in vitro and in vivo systems we identified that IL-12/IFNg down-regulated miR-10a and its putative transcription factor, Creb. Importantly, we demonstrated that miR-10a controls a suite of genes that regulate IFNg production in Th1-Treg cells. Also, Treg cells treated with IL-4 increased miR-182 and its putative transcription factor, cMaf. Up-regulation of miR-182 mitigated IL-2 secretion, in part through repression of IL2-promoting genes, including Bach2 and Cd2ap. This study indicates that CD4+Foxp3+ cells are influenced by their environment, and that Th1 or Th2 environments promote distinct miRNA pathways, preserving Treg stability and suppressor function. mouse infection vs. naïve
Project description:A variety of CD4+Foxp3+ Treg cell types have been described previously, indicating molecular heterogeneity within the Foxp3+ pool of CD4+ T cells. However, the factors that shape the transcriptomic identities of different Foxp3+ Treg cells are poorly understood. To identify the molecular pathways involved, we isolated CD4+Foxp3gfp+ cells from Th1-rich or Th2-rich environments following chronic Leishmania major or Schistosoma mansoni infection, respectively. Whole genome expression profiling and next generation small RNA sequencing revealed significantly different mRNA and miRNA profiles. In-silico analyses identified miR-10a and miR-182 as ‘regulatory miRNA hubs’ in CD4+Foxp3+ cells in Th1 and Th2-environments, respectively. Using in vitro and in vivo systems we identified that IL-12/IFNg down-regulated miR-10a and its putative transcription factor, Creb. Importantly, we demonstrated that miR-10a controls a suite of genes that regulate IFNg production in Th1-Treg cells. Also, Treg cells treated with IL-4 increased miR-182 and its putative transcription factor, cMaf. Up-regulation of miR-182 mitigated IL-2 secretion, in part through repression of IL2-promoting genes, including Bach2 and Cd2ap. This study indicates that CD4+Foxp3+ cells are influenced by their environment, and that Th1 or Th2 environments promote distinct miRNA pathways, preserving Treg stability and suppressor function.
Project description:MicroRNAs are non-coding regulators of gene expression, which act by repressing protein translation and/or degrading mRNA. Many have been shown to drive tumorigenesis in cancer, but functional studies to understand their mode of action are typically limited to single target genes. In this study we use synthetic biotinylated miRNA to pull down endogenous targets of miR-182. We identified over 1000 genes as potential targets of miR-182, most of which have a known function in pathways underlying tumour biology. Specifically, functional enrichment analysis identified components of both the DNA damage response pathway and cell cycle to be highly represented in this target cohort. Experimental validation confirmed that miR-182 mediated disruption of the homologous recombination (HR) pathway is a consequence of its ability to target multiple components in that pathway. Although there is a strong enrichment for the cell cycle ontology, we do not see a direct biological effect as a consequence of miR-182 over expression. We highlight targets which could be responsible for miR-182 mediated disruption of other biological processes attributed in the literature so far. Finally we show that miR-182 is highly expressed in a panel of human breast cancer samples highlighting its role as a potential oncomir in breast cancer. HEK293T cells were transfected with biotinylated miR-182 or a mock control. The miRNAs and target mRNA were pulled down with streptavidin and compared to the control.
Project description:MicroRNAs are non-coding regulators of gene expression, which act by repressing protein translation and/or degrading mRNA. Many have been shown to drive tumorigenesis in cancer, but functional studies to understand their mode of action are typically limited to single target genes. In this study we use synthetic biotinylated miRNA to pull down endogenous targets of miR-182. We identified over 1000 genes as potential targets of miR-182, most of which have a known function in pathways underlying tumour biology. Specifically, functional enrichment analysis identified components of both the DNA damage response pathway and cell cycle to be highly represented in this target cohort. Experimental validation confirmed that miR-182 mediated disruption of the homologous recombination (HR) pathway is a consequence of its ability to target multiple components in that pathway. Although there is a strong enrichment for the cell cycle ontology, we do not see a direct biological effect as a consequence of miR-182 over expression. We highlight targets which could be responsible for miR-182 mediated disruption of other biological processes attributed in the literature so far. Finally we show that miR-182 is highly expressed in a panel of human breast cancer samples highlighting its role as a potential oncomir in breast cancer.
Project description:The epidemiologic association between statin use and decreased risk of advanced prostate cancer suggests that statins may inhibit prostate cancer development and/or progression. Studies were performed to determine the effects of a model statin, atorvastatin (ATO), on the proliferation and differentiation of prostate cancer cells, and to identify possible mechanisms of ATO action. ATO inhibited the in vitro proliferation of both LNCaP and PC3 human prostate cancer cells in dose-dependent fashion. The greater inhibitory activity of ATO in PC3 cells was associated with induction of autophagy in that cell line, as demonstrated by increased expression of LC3-II. miR-182 was consistently upregulated by ATO in PC3 cells, but not in LNCaP cells. ATO upregulation of miR-182 in PC3 cells was p53-independent and was reversed by geranylgeraniol. Transfection of miR-182 inhibitors decreased expression of miR-182 by >98% and attenuated the antiproliferative activity of ATO. miR-182 expression in PC3 cells was also increased in response to stress induced by serum withdrawal, suggesting that miR-182 upregulation can occur due to nutritional stress. Bcl2 and p21 were identified to be potential target genes of miR-182 in PC3 cells. Bcl2 was downregulated and p21 was upregulated in PC3 cells exposed to ATO. These data suggest that miR-182 may be a stress-responsive miRNA that mediates ATO action in prostate cancer cells.
Project description:The epidemiologic association between statin use and decreased risk of advanced prostate cancer suggests that statins may inhibit prostate cancer development and/or progression. Studies were performed to determine the effects of a model statin, atorvastatin (ATO), on the proliferation and differentiation of prostate cancer cells, and to identify possible mechanisms of ATO action. ATO inhibited the in vitro proliferation of both LNCaP and PC3 human prostate cancer cells in dose-dependent fashion. The greater inhibitory activity of ATO in PC3 cells was associated with induction of autophagy in that cell line, as demonstrated by increased expression of LC3-II. miR-182 was consistently upregulated by ATO in PC3 cells, but not in LNCaP cells. ATO upregulation of miR-182 in PC3 cells was p53-independent and was reversed by geranylgeraniol. Transfection of miR-182 inhibitors decreased expression of miR-182 by >98% and attenuated the antiproliferative activity of ATO. miR-182 expression in PC3 cells was also increased in response to stress induced by serum withdrawal, suggesting that miR-182 upregulation can occur due to nutritional stress. Bcl2 and p21 were identified to be potential target genes of miR-182 in PC3 cells. Bcl2 was downregulated and p21 was upregulated in PC3 cells exposed to ATO. These data suggest that miR-182 may be a stress-responsive miRNA that mediates ATO action in prostate cancer cells.