Project description:miR-155 transgenic mice develop pre-B cell leukemia/lymphoma. Though some targets of miR-155 are known, understanding of the mechanism by which miR-155 overexpression drives malignant transformation is not known. MicroRNAs regulate multiple genes.
Project description:miR-155 transgenic mice develop pre-B cell leukemia/lymphoma. Though some targets of miR-155 are known, understanding of the mechanism by which miR-155 overexpression drives malignant transformation is not known. MicroRNAs regulate multiple genes. 3 transgenic and 4 wild type mice B-cells were analyzed
Project description:Overexpression of miR-155 in hematological tissue leads to the onset of lymphoma, and Tet-off shutdown of this overexpression reverses the disease phenotype in mir-155LSLtTA mice. This study compares the gene expression profiles of tumors with miR-155 overexpression and withdrawal. Examination of mRNA from 2 conditions: miR-155 overexpressing tumors and miR-155 overexpressing tumors from mice exposed to doxycycline (DOX) for 16hrs prior to harvest; samples in triplicate; tumors generated in flanks of nude mice by subcutaneous injection of splenic cells from diseased mir-155LSLtTA mice.
Project description:Overexpression of miR-155 in hematological tissue leads to the onset of lymphoma, and Tet-off shutdown of this overexpression reverses the disease phenotype in mir-155LSLtTA mice. This study compares the gene expression profiles of tumors with miR-155 overexpression and withdrawal.
Project description:We used microarrays to characterize the gene expression changes in liver caused by high fat diet feeding to C57BL/6 WT and miR-155-/- mice. Livers were collected from male mice at 24 weeks of age for RNA extraction and hybridization on Affymetrix mouse gene 1.0 ST array . We extracted RNA from 3 animals/group for microarray analysis (total N = 6 samples)
Project description:Several studies have indicated an important role for miR-155 in the pathogenesis of B-cell lymphoma. Highly elevated levels of miR-155 were indeed observed in most B-cell lymphomas with the exception of Burkitt lymphoma (BL). However, the molecular mechanisms that underlie the oncogenic role of miR-155 in B-cell lymphoma are not well understood. To identify the miR-155 targets relevant for B-cell lymphoma, we performed RNA immunoprecipitation of Argonaute 2 in Hodgkin lymphoma (HL) cells upon miR-155 inhibition and in BL cells upon ectopic expression of miR-155. We identified 54 miR-155-specific target genes in BL cells and confirmed miR-155 targeting of DET1, NIAM, TRIM32, HOMEZ, PSIP1 and JARID2. Five of these targets are also regulated by endogenous miR-155 in HL cells. Both overexpression of miR-155 and inhibition of expression of the novel miR-155 target gene NIAM increased proliferation of BL cells. In primary B-cell lymphoma NIAM-positive cases have significant lower levels of miR-155 as compared to NIAM-negative cases, suggesting that NIAM is also regulated by miR-155 in primary B-cell lymphoma. Thus, our data indicate an oncogenic role for miR-155 in B-cell lymphoma which involves targeting the tumor suppressor NIAM.
Project description:Several studies have indicated an important role for miR-155 in the pathogenesis of B-cell lymphoma. Highly elevated levels of miR-155 were indeed observed in most B-cell lymphomas with the exception of Burkitt lymphoma (BL). However, the molecular mechanisms that underlie the oncogenic role of miR-155 in B-cell lymphoma are not well understood. To identify the miR-155 targets relevant for B-cell lymphoma, we performed RNA immunoprecipitation of Argonaute 2 in Hodgkin lymphoma (HL) cells upon miR-155 inhibition and in BL cells upon ectopic expression of miR-155. We identified 54 miR-155-specific target genes in BL cells and confirmed miR-155 targeting of DET1, NIAM, TRIM32, HOMEZ, PSIP1 and JARID2. Five of these targets are also regulated by endogenous miR-155 in HL cells. Both overexpression of miR-155 and inhibition of expression of the novel miR-155 target gene NIAM increased proliferation of BL cells. In primary B-cell lymphoma NIAM-positive cases have significant lower levels of miR-155 as compared to NIAM-negative cases, suggesting that NIAM is also regulated by miR-155 in primary B-cell lymphoma. Thus, our data indicate an oncogenic role for miR-155 in B-cell lymphoma which involves targeting the tumor suppressor NIAM.
Project description:MicroRNA-155 (miR-155) is upregulated in primary effector CD8 T cells but is expressed at low amounts in naïve cells. Anti-viral CD8 T cell responses and viral clearance were impaired in miR-155 deficient (bic-/-) mice, and this defect was intrinsic to CD8 T cells, as adoptively transferred bic-/- CD8 T cells generated greatly reduced primary and memory responses during infection. To understand the mechanism by which miR-155 regulates CD8 T cell activation, we analyzed the gene expression profiles of naive and in vitro activated wild-type and bic-/- CD8 T cells.
Project description:Several studies have indicated an important role for miR-155 in the pathogenesis of B-cell lymphoma. Highly elevated levels of miR-155 were indeed observed in most B-cell lymphomas with the exception of Burkitt lymphoma (BL). However, the molecular mechanisms that underlie the oncogenic role of miR-155 in B-cell lymphoma are not well understood. To identify the miR-155 targets relevant for B-cell lymphoma, we performed RNA immunoprecipitation of Argonaute 2 in Hodgkin lymphoma (HL) cells upon miR-155 inhibition and in BL cells upon ectopic expression of miR-155. We identified 54 miR-155-specific target genes in BL cells and confirmed miR-155 targeting of DET1, NIAM, TRIM32, HOMEZ, PSIP1 and JARID2. Five of these targets are also regulated by endogenous miR-155 in HL cells. Both overexpression of miR-155 and inhibition of expression of the novel miR-155 target gene NIAM increased proliferation of BL cells. In primary B-cell lymphoma NIAM-positive cases have significant lower levels of miR-155 as compared to NIAM-negative cases, suggesting that NIAM is also regulated by miR-155 in primary B-cell lymphoma. Thus, our data indicate an oncogenic role for miR-155 in B-cell lymphoma which involves targeting the tumor suppressor NIAM.
Project description:Differential gene expression profile of CD4+ T cells from 10 months old Wt, miR-155-/-, miR-146a-/- and DKO mice spleens. Wt, miR-155-/-, miR-146a-/- and DKO mice were aged 10 months, CD4+ T cells were sorted from mice spleens for analyses.