Project description:P21-activated kinase 1 (Pak1) is a key oncogenic kinase and a lot of work about the mechanism of Pak1 action in cancer have been reported, while it remains unknown whether Pak1 could potentially regulate the biology of regulatory miRNAs by new interacting substrate. Here, we identified that Pak1 modulated the miR-132 expression in gastric cancer cells. Pak1 interacted with and phosphorylated activating transcription factor-2 (ATF2) on Serine 62 (Ser62), which blocked ATF2 translocation into cell nucleus. We further demonstrated that ATF2 induced miR-132 transcription via binding to the miR-132 promoter in the -30 to -39 region. Moreover, overexpression of miR-132 in gastric cancer cells significantly reduced cell adhesion, migration and invasion in vitro and hematogenous metastasis in vivo. MiR-132 targeted CD44 and fibronectin (FN) and promoted lymphocytes to gather around gastric cancer cells and kill them. More importantly, downregulation of miR-132 in gastric cancer was specifically associated with hematogenous metastasis, instead of lymph node or implantation metastasis. Taken together, miR-132 is a key negative regulator in the hematogenous metastasis of gastric cancer. A novel cell signaling pathway Pak1-ATF2-miR-132-CD44/FN is established and may be a new therapeutic target for hematogenous metastasis of gastric caner.
Project description:microRNA regulates cellular responses to ionizing radiation (IR) through the translational control of target genes. We analyzed time-series changes in microRNA expressions upon γ-irradiation in H1299 lung cancer cell lines using microarray. Significantly changed microRNAs were selected based on ANOVA analysis, target genes of which were enriched to MAPK signaling pathway. Concurrent analysis of mRNA and microRNA uncovered that the expression of miR-26b and its target ATF2 mRNA were inversely correlated in γ-irradiated H1299 cells. The overexpression of miR-26b induced the suppression of ATF2 in γ-irradiated cells. When we inhibit the MAPK signaling pathway using SP600125, JNK inhibitor, the expression of miR-26b was induced even in γ-irradiated H1299 cells. From these results, we concluded that the expression of miR-26b was coordinated regulated by MAPK signaling pathway upon ionizing radiation, and MAPK signaling pathway was regulated by miR-26b in turn. We analyzed the time-series miRNA profiles of radioresistant H1299 cells in response to 2 Gy of ionizing radiation (IR) by performing quadratic regression (QR) analysis to identify genes associated with radioresistance
Project description:microRNA regulates cellular responses to ionizing radiation (IR) through the translational control of target genes. We analyzed time-series changes in microRNA expressions upon γ-irradiation in H1299 lung cancer cell lines using microarray. Significantly changed microRNAs were selected based on ANOVA analysis, target genes of which were enriched to MAPK signaling pathway. Concurrent analysis of mRNA and microRNA uncovered that the expression of miR-26b and its target ATF2 mRNA were inversely correlated in γ-irradiated H1299 cells. The overexpression of miR-26b induced the suppression of ATF2 in γ-irradiated cells. When we inhibit the MAPK signaling pathway using SP600125, JNK inhibitor, the expression of miR-26b was induced even in γ-irradiated H1299 cells. From these results, we concluded that the expression of miR-26b was coordinated regulated by MAPK signaling pathway upon ionizing radiation, and MAPK signaling pathway was regulated by miR-26b in turn.
Project description:MicroRNAs have emerged as key regulators of B cell fate decisions and immune function. Deregulation of several microRNAs in B cells leads to the development of autoimmune disease and cancer in mice. We demonstrate that the microRNA-212/132 cluster (miR-212/132) is induced in B cells in response to B cell receptor signaling. Enforced expression of miR-132 results in a block in early B cell development at the pre-pro-B cell to pro-B cell transition and induces apoptosis in primary bone marrow B cells. Importantly, loss of miR-212/132 results in increased B cell output under non-homeostatic conditions. We find that miR-212/132 regulates B lymphopoiesis by targeting the transcription factor SOX4. Co-expression of SOX4 with miR-132 rescues the defect in B cell development from over-expression of miR-132 alone. In addition, we show that the expression of miR-132 in cells that are prone to spontaneous B cell cancers can have a protective effect on cancer development. We have thus uncovered a novel regulator of B cell lineage specification that may potential applications in B cell cancer therapy RNA-seq of wild-type and microRNA-212/132 knock-out B-cells after IgM stimulation
Project description:The colonization of distant organs by metastatic carcinoma cells underpins most human cancer-related deaths, including those from head and neck squamous cell carcinoma (HNSCC). We report that miR-203, a miRNA that promotes keratinocyte differentiation, is necessary and sufficient to inhibit multiple post-extravasation events during HNSCC lung metastasis, including initial survival/engraftment, escape from metastatic dormancy, and overt colonization in vivo. Restoration of miR-203 expression in established lung metastases reduces overall metastatic burden. Instead of promoting differentiation, miR-203 controls lung metastasis through direct targeting of genes involved in cytoskeletal dynamics (LASP1), ECM remodeling (SPARC), and cell metabolism (NUAK1). Expression of miR-203 and its downstream targets correlates with HNSCC overall survival outcomes, suggesting the therapeutic potential of targeting this signaling axis. Total RNA (including small RNAs) was isolated from cultured cells stably infected in biological duplicate with either a scrambled control hairpin or miR-203. Samples were harvested in technical duplicate.
Project description:MicroRNAs have emerged as key regulators of B cell fate decisions and immune function. Deregulation of several microRNAs in B cells leads to the development of autoimmune disease and cancer in mice. We demonstrate that the microRNA-212/132 cluster (miR-212/132) is induced in B cells in response to B cell receptor signaling. Enforced expression of miR-132 results in a block in early B cell development at the pre-pro-B cell to pro-B cell transition and induces apoptosis in primary bone marrow B cells. Importantly, loss of miR-212/132 results in increased B cell output under non-homeostatic conditions. We find that miR-212/132 regulates B lymphopoiesis by targeting the transcription factor SOX4. Co-expression of SOX4 with miR-132 rescues the defect in B cell development from over-expression of miR-132 alone. In addition, we show that the expression of miR-132 in cells that are prone to spontaneous B cell cancers can have a protective effect on cancer development. We have thus uncovered a novel regulator of B cell lineage specification that may potential applications in B cell cancer therapy
Project description:The colonization of distant organs by metastatic carcinoma cells underpins most human cancer-related deaths, including those from head and neck squamous cell carcinoma (HNSCC). We report that miR-203, a miRNA that promotes keratinocyte differentiation, is necessary and sufficient to inhibit multiple post-extravasation events during HNSCC lung metastasis, including initial survival/engraftment, escape from metastatic dormancy, and overt colonization in vivo. Restoration of miR-203 expression in established lung metastases reduces overall metastatic burden. Instead of promoting differentiation, miR-203 controls lung metastasis through direct targeting of genes involved in cytoskeletal dynamics (LASP1), ECM remodeling (SPARC), and cell metabolism (NUAK1). Expression of miR-203 and its downstream targets correlates with HNSCC overall survival outcomes, suggesting the therapeutic potential of targeting this signaling axis.
Project description:Despite some success of pharmacotherapies targeting primarily neurohormonal dysregulation, heart failure is a growing global pandemic with increasing burden. Treatments that improve the disease by reversing heart failure at the cardiomyocyte level are lacking. MicroRNAs (miRNA) are transcriptional regulators of gene expression, acting through complex biological networks, and playing thereby essential roles in disease progression. Adverse structural remodelling of the left ventricle due to myocardial infarction (MI) is a common pathological feature leading to heart failure. We previously demonstrated increased cardiomyocyte expression of the miR-212/132 family during pathological cardiac conditions. Transgenic mice overexpressing the miR-212/132 cluster (miR-212/132-TG) develop pathological cardiac remodelling and die prematurely from progressive HF. Using both knockout and antisense strategies, we have shown miR-132 to be both necessary and sufficient to drive the pathological growth of cardiomyocytes in a murine model of left ventricular pressure overload. Based on the findings, we proposed that miR-132 may serve as a therapeutic target in heart failure therapy. Here we provide novel mechanistic insight and translational evidence for the therapeutic efficacy in small and large animal models (n=135) of heart failure. We demonstrate strong PK/PD relationship, dose-dependent efficacy and high clinical potential of a novel optimized synthetic locked nucleic acid phosphorothioate backbone antisense oligonucleotide inhibitor of miR-132 (antimiR-132) as a next-generation heart failure therapeutic.
Project description:MicroRNAs (miRNAs) negatively regulate protein-coding genes at the post-transcriptional level and are critical in tumorigenesis. Schwannomas develop from proliferation of dedifferentiated Schwann cells, which normally wrap around nerve fibers to help support and insulate nerves. In this study, we carried out high-throughput miRNA expression profiling of human vestibular schwannomas using an array representing 407 known miRNAs in order to explore the role of miRNAs in tumor growth. Twelve miRNAs were found to be significantly deregulated in tumor samples as compared with control nerve tissue, defining a schwannoma-typical signature. Among these miRNAs, we focused on miR-7 which was one of the most downregulated in these tumors and has several known oncogene targets, including mRNAs for epidermal growth factor receptor (EGFR) and p21-activated kinase 1 (Pak1). We found that overexpression of miR-7 inhibited schwannoma cell growth both in culture and in a xenograft tumor model in vivo, which correlated with downregulation of these signaling pathways. Furthermore, we identified a novel direct target of miR-7, the mRNA for associated cdc42 kinase 1 (Ack1), with the expression levels of miR-7 and Ack1 being inversely correlated in human schwannoma samples. These findings are the first analyzing miRNA profiles of schwannomas and support a “tumor suppressor” function for miR-7 in these tumors by targeting proteins in three major oncogenic pathways, EGFR, Pak1, and Ack1. Moreover, our result also suggest that miR-7 may serve as a potential therapeutic molecule for schwannomas and that drugs which inhibit these signaling pathways could suppress growth of these benign tumors. Schwannoma tumor samples are compared to nerve controls