Project description:Adult beta cells in the pancreas are the sole source of insulin in our body. Beta cell loss or increased demand for insulin, impose metabolic challenges because adult beta cells are generally quiescent and infrequently re-enter the cell division cycle. miR-17-92/106b is a family of proto-oncogene microRNAs, that regulate proliferation in normal tissues and in cancer. Here, we employ mouse genetics to demonstrate a critical role for miR-17-92/106b in glucose homeostasis and in controlling insulin secretion. Mass spectrometry analysis was performed on miR-17-92LoxP/LoxP;106-25-/- MEF lysate, without or with CRE-Adenovirus. miR-17-92LoxP/LoxP;106-25+/+ MEFs with GFP-Adenovirus served as controls. We demonstrate that miR-17-92/106b regulate the adult beta cell mitotic checkpoint and that miR-17-92/106b deficiency results in reduction in beta cell mass in-vivo. Furthermore, protein kinase A (PKA) is a new relevant molecular pathway downstream of miR-17-92/106b in control of adult beta cell division and glucose homeostasis. Therefore, contributes to the understanding of proto-oncogene miRNAs in the normal, untransformed endocrine pancreas, and illustrates new genetic means for regulation of beta cell mitosis and function by non-coding RNAs.
Project description:We and others previously reported that the miR-106b-25 microRNA cluster is a candidate oncogene in human prostate cancer. Here, we made the novel observation that miR-106b-25 expression is further up-regulated in distant metastasis. Moreover, increased tumor miR-106b expression was associated with early disease recurrence. To identify yet unknown oncogenic functions of the prognostic miR-106b, we overexpressed it in LNCaP human prostate cancer cells to examine miR-106b-induced global expression changes among protein-coding genes. The approach revealed that caspase-7 is a candidate direct target of miR-106b, which was confirmed by Western blot analysis and a 3’UTR reporter assay. Other analyses showed that caspase-7 is down-regulated in primary human prostate tumors and metastatic lesions across multiple datasets and is by itself associated with disease recurrence. Using bioinformatics, we also discovered that miR-106b-25 may specifically influence focal adhesion-related pathways. This observation was experimentally confirmed using miR-106b-25-transduced 22Rv1 human prostate cancer cells. After infection with a miR-106b-25 lentiviral expression construct, 22Rv1 cells showed increased adhesion to basement membrane- and bone matrix-related filaments and enhanced soft agar growth. In summary, miR-106b-25 was found to be associated with prostate cancer progression and metastasis and may do so by altering apoptosis- and focal adhesion-related pathways. To elucidate the effects miR-106b, we up-regulated miR-106b in LNCaP cells and examined gene expression alterations on a global scale with Affymetrix arrays.
Project description:We and others previously reported that the miR-106b-25 microRNA cluster is a candidate oncogene in human prostate cancer. Here, we made the novel observation that miR-106b-25 expression is further up-regulated in distant metastasis. Moreover, increased tumor miR-106b expression was associated with early disease recurrence. To identify yet unknown oncogenic functions of the prognostic miR-106b, we overexpressed it in LNCaP human prostate cancer cells to examine miR-106b-induced global expression changes among protein-coding genes. The approach revealed that caspase-7 is a candidate direct target of miR-106b, which was confirmed by Western blot analysis and a 3M-bM-^@M-^YUTR reporter assay. Other analyses showed that caspase-7 is down-regulated in primary human prostate tumors and metastatic lesions across multiple datasets and is by itself associated with disease recurrence. Using bioinformatics, we also discovered that miR-106b-25 may specifically influence focal adhesion-related pathways. This observation was experimentally confirmed using miR-106b-25-transduced 22Rv1 human prostate cancer cells. After infection with a miR-106b-25 lentiviral expression construct, 22Rv1 cells showed increased adhesion to basement membrane- and bone matrix-related filaments and enhanced soft agar growth. In summary, miR-106b-25 was found to be associated with prostate cancer progression and metastasis and may do so by altering apoptosis- and focal adhesion-related pathways. To elucidate the effects miR-106b, we up-regulated miR-106b in LNCaP cells and examined gene expression alterations on a global scale with Affymetrix arrays. LNCaP cells were transfected with pre-miR oligos and 24 hr post-transfection total RNA was collected for microarray anaylsis.
Project description:We have generated a miR-17~92 fl/fl allele whose expression can be turned off conditionally by Cre recombinase in the miR-106a-363-/-;miR-106b-25-/- background. The mice were crossed to CD19-Cre mice to turn off the expression of miR-17~92 specifically in B cells.
Project description:We have generated a miR-17~92 transgene and fl/fl allele whose expression can be turned on and off conditionally by Cre recombinase. The mice were crossed to CD19-Cre mice to turn on and off the expression of miR-17~92 specifically in B cells and stimulated LPS/IL-4 for 25.5hr. tKO mice were generated in the miR-106a-363-/-;miR-106b-25-/- background, so that all three homologous cluster of miR-17~92 family miRNAs are deleted in B cells.
Project description:We have generated a miR-17~92 fl/fl allele whose expression can be turned off conditionally by Cre recombinase in the miR-106a-363-/-;miR-106b-25-/- background. The mice were crossed to CD19-Cre mice to turn off the expression of miR-17~92 specifically in B cells. Follicular B(FoB) cells were purified from CD19-Cre;miR-17~92 fl/fl;miR-106a-363;miR-106b~25 mice (tKO1, tKO2, tKO3) and CD19-cre (Control1, Control2, Control3) by MACS depletion of cells positive for CD9, CD43, and CD93 (also known as AA4.1). The purity of follicular B cells was examined by flow cytometry and was greater than 95% for all samples. Total RNA was extracted using RNeasy kit (QIAGEN).
Project description:We investigated the miRNA cluster miR-106b~25 as potential candidate causing male infertility. We analized single and double KO mice. Single KO show derregulation of multiple molecular pathways and disrupted early spermatogenesys, but retain fertility. Double KO show severely disrupted testicular histology and significantly reduced fertility.
Project description:We have generated a miR-17~92 fl/fl allele whose expression can be turned off conditionally by Cre recombinase in the miR-106a-363-/-;miR-106b-25-/- background. The mice were crossed to CD19-Cre mice to turn off the expression of miR-17~92 specifically in B cells and stimulated LPS/IL-4 for 13.5hr.