Project description:Human serum derived macrophages were infected with Mtb expressing a transcriptional reporter of viability and on day 5, the cells were sorted for RFP+GFP+ macrophages or RFP+GFP- macrophages.
Project description:ES derived Flk-1+ cells were separated by sorting into Hoxb6 positive and negative populations by RFP Hoxb6 reporter. Gene expression was compared between these two groups. Duplicate analysis of Hoxb6-RFP positive and negative Flk-1+ cells.
Project description:ES derived Flk-1+ cells were separated by sorting into Hoxb6 positive and negative populations by RFP Hoxb6 reporter. Gene expression was compared between these two groups.
Project description:SK-MEL-2 cells treated with Ad-E2F-1 (MOI 2), Ad-E2F-1 (MOI 2)plus doxorubicin 0.1uM, or Ad-LacZ (MOI 2) plus doxorubicin 0.1uM. The combination of E2F-1 gene therapy and chemotherapy produces a synergistic effect on melanoma cell apoptosis. However, the molecular mechanisms have not been fully elucidated. The purpose of this study was to identify novel genes or pathways that may play key roles in apoptosis when E2F-1 gene therapy is combined with doxorubicin chemotherapy. MATERIALS AND METHODS: SK-MEL-2 melanoma cells were infected with Ad-E2F-1 alone, Ad-E2F-1 plus doxorubicin, or Ad-LacZ plus doxorubicin. After 16 hours of treatment, the total RNA was extracted from these cells and subjected to microarray analysis. Quantitative real-time PCR was performed to confirm the microarray data. RESULTS: Our results showed that the combination treatment of Ad-E2F-1 and doxorubicin affected the expression of cytokines, transcription factors, as well as genes involved in signal transduction, cell cycle regulation and apoptosis. CONCLUSION: Our findings have identified, for the first time, novel molecular targets and pathways that led to apoptosis in melanoma cells when Ad-E2F-1 was combined with doxorubicin. The molecular information provided here will enhance further mechanistic studies.
Project description:Mutations in cancer are due in part to DNA cytosine deamination by APOBEC3B (A3B). While low in healthy tissues, A3B expression and activity are elevated in tumors and further increase in metastases. However, molecular mechanisms responsible for A3B transcriptional regulation are poorly understood. Here, we address whether the RB/E2F pathway, which is often dysregulated in breast cancer, is a molecular trigger of A3B overexpression. First, an A3B promoter-driven luciferase reporter was used to demonstrate reporter activation by disruption of only one out of five predicted E2F binding sites. Second, A3B-luciferase reporter activation was also triggered by expressing the BK polyomavirus T-antigen, which inactivates RB and thereby alleviates repression of E2F regulated genes. Importantly, A3B-luciferase reporter induction by BK polyomavirus T-antigen could not be further increased by mutating the functional E2F binding site. Third, both CRISPR disruption and targeted base substitutions in the endogenous E2F binding site caused strong A3B upregulation and confirmed importance of this regulatory element. Fourth, proteomics experiments showed that members of the DREAM and PRC1.6-complexes including multiple E2F family members are able to bind to wild-type but not E2F mutant promoter sequences. Finally, a combination of genetic and biochemical studies implicated E2F4 and E2F6 in endogenous A3B gene repression. Altogether, our studies demonstrate that A3B expression is suppressed in normal cells by the RB/E2F axis and that viral or mutational disruption of this pathway causes overexpression of this DNA deaminase in cancer and contributes mutational fuel to tumor evolution.
Project description:This experiment examines how increasing stress (sorbitol) can override normal stemness (NS) conditions, which LIF maintains, causing lineage imbalance and otherwise affecting cells in the early embryo. It also compares NS to normal differentiation (ND) (without LIF). D3 are from 8 blastocysts of 129/Sv+/+ strain mice germ line competent 1. No sex is given as these may actually be a product of different sexes of the 8 blastocysts. The D3 cells were obtained for ATCC (American Type Culture Collection). 1. Doetschman TC, Eistetter H, Katz M, Schmidt W, Kemler R. The in vitro development of blastocyst-derived embryonic stem cell lines: formation of visceral yolk sac, blood islands and myocardium. J Embryol Exp Morphol 1985;87:27-45. Rex1 promoter- Red fluorescence protein (RFP) transgenic viable reporter ESC were created and validated previously2. 2. Li Q, Gomez-Lopez N, Drewlo S, et al. Development and Validation of a Rex1-RFP Potency Activity Reporter Assay That Quantifies Stress-Forced Potency Loss in Mouse Embryonic Stem Cells. Stem Cells Dev 2016;25:320-8.
Project description:This experiment examines how increasing stress (sorbitol) can override normal stemness (NS) conditions, which LIF maintains, causing lineage imbalance and otherwise affecting cells in the early embryo. It also compares NS to normal differentiation (ND) (without LIF). D3 are from 8 blastocysts of 129/Sv+/+ strain mice germ line competent 1. No sex is given as these may actually be a product of different sexes of the 8 blastocysts. The D3 cells were obtained for ATCC (American Type Culture Collection). 1. Doetschman TC, Eistetter H, Katz M, Schmidt W, Kemler R. The in vitro development of blastocyst-derived embryonic stem cell lines: formation of visceral yolk sac, blood islands and myocardium. J Embryol Exp Morphol 1985;87:27-45. Rex1 promoter- Red fluorescence protein (RFP) transgenic viable reporter ESC were created and validated previously2. 2. Li Q, Gomez-Lopez N, Drewlo S, et al. Development and Validation of a Rex1-RFP Potency Activity Reporter Assay That Quantifies Stress-Forced Potency Loss in Mouse Embryonic Stem Cells. Stem Cells Dev 2016;25:320-8.
Project description:Most E2F-binding sites repress transcription through the recruitment of Retinoblasoma (RB) family members until the end of the G1 cell-cycle phase. Although the MYB promoter contains an E2F-binding site, its transcription is activated shortly after the exit from quiescence, before RB family members inactivation, by unknown mechanisms. We had previously uncovered a nuclear factor distinct from E2F, Myb-sp, whose DNA-binding site overlapped the E2F element and had hypothesized that this factor might overcome the transcriptional repression of MYB by E2F-RB family members. We have purified Myb-sp and discovered that Myc-associated zinc finger proteins (MAZ) are major components. We show that various MAZ isoforms are present in Myb-sp and activate transcription via the MYB-E2F element. Moreover, while forced RB or p130 expression repressed the activity of a luciferase reporter driven by the MYB-E2F element, co-expression of MAZ proteins not only reverted repression, but also activated transcription. Finally, we show that MAZ binds the MYB promoter in vivo, that its binding site is critical for MYB transactivation, and that MAZ knockdown inhibits MYB expression during the exit from quiescence. Together, these data indicate that MAZ is essential to bypass MYB promoter repression by RB family members and to induce MYB expression.