Project description:Small RNAs play a critical role in host-pathogen interaction and microRNAs have emerged as key regulators of viral infections. Based on this evidence, we wished to contribute to this research field by identifying and characterizing cellular microRNAs with a positive or negative role on Sindbis virus (SINV) infection.
Project description:microRNA dysregulation is a common feature of cancer cells, but the complex roles of microRNAs in cancer are not fully elucidated. Here we used functional genomics to identify oncogenic microRNAs in non-small cell lung cancer and to evaluate their impact on response to EGFR targeting therapy. Our data demonstrate that microRNAs with an AAGUGC-motif in their seed-sequence increase both cancer cell proliferation and sensitivity to EGFR inhibitors. Global transcriptomics, proteomics and target prediction resulted in the identification of several tumor suppressors involved in the G1/S transition as targets of AAGUGC-microRNAs. The clinical implications of our findings were evaluated by analysis of public domain data supporting the link between this microRNA seed-family, their tumor suppressor targets and cancer cell proliferation. In conclusion we propose that AAGUGC-microRNAs are an integral part of an oncogenic signaling network, and that these findings have potential therapeutic implications, especially in selecting patients for EGFR-targeting therapy.
Project description:microRNA dysregulation is a common feature of cancer cells, but the complex roles of microRNAs in cancer are not fully elucidated. Here we used functional genomics to identify oncogenic microRNAs in non-small cell lung cancer and to evaluate their impact on response to EGFR targeting therapy. Our data demonstrate that microRNAs with an AAGUGC-motif in their seed-sequence increase both cancer cell proliferation and sensitivity to EGFR inhibitors. Global transcriptomics, proteomics and target prediction resulted in the identification of several tumor suppressors involved in the G1/S transition as targets of AAGUGC-microRNAs. The clinical implications of our findings were evaluated by analysis of public domain data supporting the link between this microRNA seed-family, their tumor suppressor targets and cancer cell proliferation. In conclusion we propose that AAGUGC-microRNAs are an integral part of an oncogenic signaling network, and that these findings have potential therapeutic implications, especially in selecting patients for EGFR-targeting therapy.
Project description:Huh-7.5.1 cells were treated with 0.2% DMSO, 20 microM NeoB for 24 h. Treatment with 0.2% DMSO for 24h was prepared as non-treated Huh7.5.1 cells. Huh7.5.1 cells were kindly provided by Prof. Francis Chisari at The Scripps Research Institute.
Project description:We analyzed the incorporation of cellular microRNAs (miRNAs) into highly purified HIV-1 virions and observed that this largely, but not entirely, mirrored the level of miRNA expression in the producer CD4+ T cells. Specifically, of the 58 cellular miRNAs detected at significant levels in the producer cells, only five miRNAs were found at a 2 to 4-fold higher level in virions than predicted based on random sampling. Of note, these included two miRNAs, miR-155 and miR-92a, reported previously to at least weakly bind HIV-1 transcripts. To test whether miRNA binding induces virion incorporation, we introduced artificial miRNA target sites into the HIV-1 genome and observed a 10 to 40-fold increase in the packaging of the cognate miRNA into virions, leading to the recruitment of up to 1.6 copies into each virion. Importantly, this high level of incorporation significantly inhibited HIV-1 virion infectivity. We conclude that target sites for cellular miRNAs can inhibit RNA virus replication at two distinct steps, i.e., during infection and during viral gene expression, thus explaining why a range of different RNA viruses appear to have evolved to restrict cellular miRNA binding to their genome.
Project description:Silymarin (SM) is a popular botanical medicine with purported liver protective effects. SM displays multiple effects in animal models and in cell culture including prevention of liver disease, reduction of inflammation, oxidative stress, and proliferation. Despite a plethora of data indicating that SM impinges on multiple cellular signaling pathways important in inflammation and disease, no unifying mechanisms have been forwarded. To define how SM elicits so many biological effects, the current study presents the first comprehensive transcriptional profiling study of human hepatoma cells treated with SM. The intention of the study was to focus on the early transcriptional events that are associated with SM-induced inhibition of proliferation and inflammation. Collectively, the data demonstrate that SM causes a rapid transcriptional reprogramming of cells that initially manifests as energy stress and slowing of cellular metabolism, leading to inhibition of cell growth and inflammation. The effects of silymarin on liver hepatoma Huh7.5.1 cells were detected using a time course approach.
Project description:Huh-7.5.1 cells were treated with 0.2% DMSO, 20 microM NeoB for 24 h. Treatment with 0.2% DMSO for 24h was prepared as non-treated Huh7.5.1 cells. Huh7.5.1 cells were kindly provided by Prof. Francis Chisari at The Scripps Research Institute. Total RNA obtained from NeoB-treated and un-treated Huh7.5.1 cells
Project description:To further elucidate the gene expression profile alterations induced by HCV infection, we have employed the Arraystar Human LncRNA Microarray V3.0 as a discovery platform to identify genes associated with HCV infection. Human hepatocellular carcinoma cell line Huh7.5.1 was infected with HCVcc for 6 h. The gene expression pattern of HCVcc-infected Huh7.5.1 was compared with that of uninfected Huh7.5.1 to identify the differentially expressed genes induced by HCV infection.
Project description:Coagulation Factor VIII (FVIII) plays a pivotal role within the coagulation cascade, and deficiencies in its levels, as seen in Hemophilia A, can lead to significant health implications. Liver sinusoidal endothelial cells (LSECs) are the main producers and contributors of FVIII in blood, a fact we have previously elucidated through mRNA expression profiling when comparing these cells to other endothelial cell types. Our current investigation delves into small microRNAs, analyzing their distinct expression patterns across various endothelial cells and hepatocytes. The outcome of this exploration underscores the discernible microRNA expression differences that set LSECs apart from both hepatocytes (193 microRNAs at p < 0.05) and other endothelial cells (72 microRNAs at p < 0.05). Notably, the 134 and 35 overexpressed microRNAs in LSECs compared to hepatocytes and other endothelial cells, respectively, shed light on the unique functions of LSECs in the liver. Our investigation identified a panel of 10 microRNAs (miR-429, miR-200b-3p, miR-200a-3p, miR-216b-5p, miR-1185-5p, miR-19b-3p, miR-192-5p, miR-122-5p, miR-30c-2-3p, and miR-30a-5p) that distinctly define LSEC identity. Furthermore, our scrutiny extended to microRNAs implicated in F8 regulation, revealing a subset - miR-122-5p, miR-214-3p, miR-204-3p, and miR-2682-5p - whose expression intricately correlates with F8 expression within LSECs. This microRNA cohort emerges as a crucial modulator of F8, both directly through suppression and indirect effects on established F8-related transcription factors. The above miRNA emerged as potential targets for innovative therapies in Hemophilia A patients.
Project description:MicroRNAs are small RNAs that regulate protein levels. It is commonly assumed that the expression level of a microRNA is directly correlated with its repressive activity – that is, highly expressed microRNAs will repress their target mRNAs more. Here we investigate the quantitative relationship between endogenous microRNA expression and repression for 32 mature microRNAs in Drosophila melanogaster S2 cells. In general, we find that more abundant microRNAs repress their targets to a greater degree. However, the relationship between expression and repression is nonlinear, such that a 10-fold greater microRNA concentration produces only a 10% increase in target repression. The expression/repression relationship is the same for both dominant guide microRNAs and minor mature products (so-called passenger strands/microRNA* sequences). However, we find examples of microRNAs whose cellular concentrations differ by several orders of magnitude, yet induce similar repression of target mRNAs. Likewise, microRNAs with similar expression can have very different repressive abilities. We show that the association of microRNAs with Argonaute proteins does not explain this variation in repression. The observed relationship is consistent with the limiting step in target repression being the association of the microRNA/RISC complex with the target site. These findings argue that modest changes in cellular microRNA concentration will have minor effects on repression of targets.