Project description:The mammalian target of rapamycin (mTOR) is a central regulator of cell proliferation. Inhibitors of mTOR are being evaluated as anti-tumor agents. Given the emerging role of microRNAs (miRNAs) in tumorgenesis we hypothesized that miRNAs could play important roles in the response of tumors to mTOR inhibitors. Rapamycin resistant myogenic cells developed by long-term rapamycin treatment showed extensive reprogramming of miRNAs expression, characterized by up-regulation of the mir-17~92 and related clusters and down-regulation of tumor-suppressor miRNAs. Antagonists of oncogenic miRNA families and mimics of tumor suppressor miRNAs (let-7) restored rapamycin sensitivity in resistant tumor cells. This study identified miRNAs as new downstream components of the mTOR-signaling pathway, which may determine the response of tumors to mTOR inhibitors. Total RNA extraction and hybridization on Affymetrix microarrays of rapamycin sensitive (RS) cells (BC3H1, mouse brain tumor cell line with myogenic properties, ATCC) cultured in Dulbecco’s modified essential medium (DMEM) media supplemented with 20% fetal bovine serum (FBS), penicillin (100 U/ml) and streptomycin (100 mg/ml). Rapamycin resistant cells (RR1) were developed by culturing BC3H1 cells in the presence of 1 uM rapamycin for 6 months. Three samples in triplicates: 1) Rapamycin sensitive cells treated with DMSO for 24 h(BC3H1, reference), 2) Rapamycin sensitive cells treated for 24 h with 100 nM rapamycin (BC3H1+R), 3) Rapamycin resistant cells constantly treated with 1uM Rapamycion (RR1+R).
Project description:The mammalian target of rapamycin (mTOR) is a central regulator of cell proliferation. Inhibitors of mTOR are being evaluated as anti-tumor agents. Given the emerging role of microRNAs (miRNAs) in tumorgenesis we hypothesized that miRNAs could play important roles in the response of tumors to mTOR inhibitors. Rapamycin resistant myogenic cells developed by long-term rapamycin treatment showed extensive reprogramming of miRNAs expression, characterized by up-regulation of the mir-17~92 and related clusters and down-regulation of tumor-suppressor miRNAs. Antagonists of oncogenic miRNA families and mimics of tumor suppressor miRNAs (let-7) restored rapamycin sensitivity in resistant tumor cells. This study identified miRNAs as new downstream components of the mTOR-signaling pathway, which may determine the response of tumors to mTOR inhibitors. Total RNA was extracted from rapamycin sensitive (RS) cells (BC3H1, mouse brain tumor cell line with myogenic properties, ATCC) cultured in Dulbecco’s modified essential medium (DMEM) media supplemented with 20% fetal bovine serum (FBS), penicillin (100 U/ml) and streptomycin (100 mg/ml). Rapamycin resistant cells (RR1) were developed by culturing BC3H1 cells in the presence of 1 uM rapamycin for 6 months. Three samples in quadruplicate 1)RS cells treated with DMSO for 24 h(BC3H1, reference), 2) RS cells treated for 24 h with 100 nM rapamycin (BC3H1+R), 3) RR1 cells consantly treated with 1uM Rapamycion (RR1+R). For each experiment, 1 μM of total RNA was labeled with Hy3TM dye and a reference RNA pool (consisting of a mixture of equal amounts of total RNA from BC3H1, BC3H1+R and RR1+R cells) was labeled with Hy5TM dye using the miRCURYTM Labeling Kit. The samples were hybridized to Exiqon miRCURYTM LNA Arrays (V10.0).
Project description:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other
Project description:The mammalian target of rapamycin (mTOR) is a central regulator of cell proliferation. Inhibitors of mTOR are being evaluated as anti-tumor agents. Given the emerging role of microRNAs (miRNAs) in tumorgenesis we hypothesized that miRNAs could play important roles in the response of tumors to mTOR inhibitors. Rapamycin resistant myogenic cells developed by long-term rapamycin treatment showed extensive reprogramming of miRNAs expression, characterized by up-regulation of the mir-17~92 and related clusters and down-regulation of tumor-suppressor miRNAs. Antagonists of oncogenic miRNA families and mimics of tumor suppressor miRNAs (let-7) restored rapamycin sensitivity in resistant tumor cells. This study identified miRNAs as new downstream components of the mTOR-signaling pathway, which may determine the response of tumors to mTOR inhibitors.
Project description:The mammalian target of rapamycin (mTOR) is a central regulator of cell proliferation. Inhibitors of mTOR are being evaluated as anti-tumor agents. Given the emerging role of microRNAs (miRNAs) in tumorgenesis we hypothesized that miRNAs could play important roles in the response of tumors to mTOR inhibitors. Rapamycin resistant myogenic cells developed by long-term rapamycin treatment showed extensive reprogramming of miRNAs expression, characterized by up-regulation of the mir-17~92 and related clusters and down-regulation of tumor-suppressor miRNAs. Antagonists of oncogenic miRNA families and mimics of tumor suppressor miRNAs (let-7) restored rapamycin sensitivity in resistant tumor cells. This study identified miRNAs as new downstream components of the mTOR-signaling pathway, which may determine the response of tumors to mTOR inhibitors.