Project description:Nonsense-mediated RNA decay (NMD) is regulated by a variety of cellular stresses. We expose U2OS cells to several stresses and assess RNA expression in the absence of transcription (i.e. stability). These studies identify transcripts that are stabilized by the physiological inhibition of NMD.
Project description:We have HA-tagged two nonsense-mediated decay proteins, UPF1 and UPF2, in the malaria parasite Plasmodium falciparum. We then performed co-immunoprecipitation experiments to determine the protein-protein interactions of these nonsense-mediated decay components.
Project description:Bidirectional communication between tumors and neurons has emerged as a key facet of the tumor microenvironment that drives malignancy. Another hallmark feature of cancer is epigenomic dysregulation, where alterations in gene expression influences cell states and interactions with the tumor microenvironment. Using the pediatric brain tumor ependymoma (EPN) as a model, we found that inhibition of histone serotonylation blocks EPN tumorigenesis and regulates expression of a core set of developmental transcription factors (TFs). High-throughput, in vivo screening of these TFs revealed that ETV5 promotes EPN tumorigenesis and functions by enhancing repressive chromatin states. Neuropeptide Y (NPY) is amongst the genes repressed by ETV5 and its overexpression suppresses EPN tumor progression and tumor-associated network hyperactivity via synaptic remodeling. Collectively, these studies identify histone serotonylation as a key driver of EPN tumorigenesis, while further revealing how neuronal signaling, neuro-epigenomics, and developmental programs are intertwined to drive malignancy in brain cancer.
Project description:Identification of novel, highly penetrant, breast cancer susceptibility genes will require the application of additional strategies beyond that of traditional linkage and candidate gene approaches. Approximately one-third of inherited genetic diseases, including breast cancer susceptibility, are caused by frameshift or nonsense mutations that truncate the protein product [1]. Transcripts harbouring premature termination codons are selectively and rapidly degraded by the nonsense-mediated mRNA decay (NMD) pathway. Blocking the NMD pathway in any given cell will stabilise these mutant transcripts, which can then be detected using gene expression microarrays. This technique, known as gene identification by nonsense-mediated mRNA decay inhibition (GINI), has proved successful in identifying sporadic nonsense mutations involved in many different cancer types. However, the approach has not yet been applied to identify germline mutations involved in breast cancer. We therefore attempted to use GINI on lymphoblastoid cell lines (LCLs) from multiple-case, non-BRCA1/2 breast cancer families in order to identify additional high-risk breast cancer susceptibility genes. We applied GINI to a total of 24 LCLs,established from breast-cancer affected and unaffected women from three multiple-case non-BRCA1/2 breast cancer families. We then used Illumina gene expression microarrays to identify transcripts stabilised by the NMD inhibition. Total RNA obtained from the lymphoblastoid cell lines derived from 24 individuals.
