Search

Multiple myeloma (MM) is a currently incurable malignancy of antibody-secreting plasma cells. Long non-coding RNAs (lncRNAs) have been recognised as an important class of regulatory molecules which are increasingly implicated in tumorigenesis. While recent studies have demonstrated changes in expression of lncRNAs in MM, the functional significance and molecular pathways downstream of these changes remain poorly characterised. In this study, we have performed CRISPR-mediated deletion of the locus encoding the lncRNA Colorectal Neoplasia Differentially Expressed (CRNDE), a known oncogenic lncRNA that is overexpressed in plasma cells of MM patients and is a marker of poor prognosis. We found that CRISPR-mediated deletion of the CRNDE locus in MM cells decreases proliferation and adhesion properties, increases sensitivity to Dexamethasone and reduces tumour growth in an in vivo xenograft model. Transcriptomic profiling in CRNDE-deleted MM cells demonstrated that CRNDE activates expression of a number of genes previously implicated in the aetiology of MM, including IL6R. We further demonstrate that deletion of the CRNDE locus diminishes IL6 signalling and proliferative responses in MM cells. Altogether this study reveals the IL6 signalling pathway as a novel mechanism by which CRNDE impacts upon MM cell growth and disease progression.

ABSTRACT: This report describes a project to annotate the background coded text of the Oxford English Dictionary (OED) with metadata, as well as various current and projected outcomes. The focus now is on the 2.436 million quotations in the 1989 Second Edition (OED2), which are being marked for author gender, textual genre, publication type, and edition of inclusion. A future phase will address the additional 1.150 million quotations added in the current version of OED Online (OED3), as well as the non-quotation text of all three editions.

We report a rapid and reliable 2-tier selection and screen for detection of activity as well as drug-resistance in mutated variants of a clinically-relevant drug-target enzyme. Human dihydrofolate reductase point-mutant libraries were subjected to a 1st-tier bacterial complementation assay, such that bacterial propagation served as an indicator of enzyme activity. Alternatively, when selection was performed in the presence of the inhibitor methotrexate (MTX), propagation indicated MTX resistance. The selected variants were then subjected to a 2nd-tier in vitro screen in 96-well plate format using crude bacterial lysate. Conditions were defined to establish a threshold for activity or for MTX resistance. The 2nd-tier assay allowed rapid detection of the best variants among the leads and provided reliable estimates of relative reactivity, (kcat) and IC50MTX. Screening saturation libraries of active-site positions 7, 15, 24, 70, and 115 revealed a variety of novel mutations compatible with reactivity as well as 2 novel MTX-resistant variants: V115A and V115C. Both variants displayed KiMTX= 20 nM, a 600-fold increase relative to the wild-type. We also present preliminary results from screening against further antifolates following simple modifications of the protocol. The flexibility and robustness of this method will provide new insights into interactions between ligands and active-site residues of this clinically relevant human enzyme.

Multiple myeloma (MM) is a malignancy of antibody-secreting plasma cells which remains incurable, despite significant improvements in treatment and patient care. MM is characterized by a wide clinical and prognostic spectrum, even within groups bearing the same primary initiating cytogenetic event, for which the molecular mechanisms responsible remain poorly understood. Long non-coding RNAs (lncRNAs; broadly defined as non-coding RNAs of > 200 nt) have recently emerged as an important class of regulatory molecules, exercising diverse functions in normal cells and tissues, and are increasingly implicated in tumorigenesis and cancer progression. However at present the contribution of lncRNAs to the progression and clinical variability of MM is largely unknown.