Hyaluronan Binding Motifs of USP17 and SDS3 Exhibit Anti-Tumor Activity

BACKGROUND: We previously reported that the USP17 deubiquitinating enzyme having hyaluronan binding motifs (HABMs) interacts with human SDS3 (suppressor of defective silencing 3) and specifically deubiquitinates Lys-63 branched polyubiquitination of SDS3 resulting in negative regulation of histone deacetylase (HDAC) activity in cancer cells. Furthermore, USP17 and SDS3 mutually interact with each other to block cell proliferation in HeLa cells but the mechanism for this inhibition in cell proliferation is not known. We wished to investigate whether the HABMs of USP17 were responsible for tumor suppression activity. METHODOLOGY/PRINCIPAL FINDINGS: Similarly to USP17, we have identified that SDS3 also has three consecutive HABMs and shows direct binding with hyaluronan (HA) using cetylpyridinium chloride (CPC) assay. Additionally, HA oligosaccharides (6-18 sugar units) competitively block binding of endogenous HA polymer to HA binding proteins. Thus, administration of HA oligosaccharides antagonizes the interaction between HA and USP17 or SDS3. Interestingly, HABMs deleted USP17 showed lesser interaction with SDS3 but retain its deubiquitinating activity towards SDS3. The deletion of HABMs of USP17 could not alter its functional regulation on SDS3-associated HDAC activity. Furthermore, to explore whether HABMs in USP17 and SDS3 are responsible for the inhibition of cell proliferation, we investigated the effect of USP17 and SDS3-lacking HABMs on cell proliferation by soft agar, apoptosis, cell migration and cell proliferation assays. CONCLUSIONS: Our results have demonstrated that these HABMs in USP17 and its substrate SDS3 are mainly involved in the inhibition of anchorage-independent tumor growth

Gene Discovery in the Threatened Elkhorn Coral: 454 Sequencing of the Acropora palmata Transcriptome

BACKGROUND: Cnidarians, including corals and anemones, offer unique insights into metazoan evolution because they harbor genetic similarities with vertebrates beyond that found in model invertebrates and retain genes known only from non-metazoans. Cataloging genes expressed in Acropora palmata, a foundation-species of reefs in the Caribbean and western Atlantic, will advance our understanding of the genetic basis of ecologically important traits in corals and comes at a time when sequencing efforts in other cnidarians allow for multi-species comparisons. RESULTS: A cDNA library from a sample enriched for symbiont free larval tissue was sequenced on the 454 GS-FLX platform. Over 960,000 reads were obtained and assembled into 42,630 contigs. Annotation data was acquired for 57% of the assembled sequences. Analysis of the assembled sequences indicated that 83-100% of all A. palmata transcripts were tagged, and provided a rough estimate of the total number genes expressed in our samples (~18,000-20,000). The coral annotation data contained many of the same molecular components as in the Bilateria, particularly in pathways associated with oxidative stress and DNA damage repair, and provided evidence that homologs of p53, a key player in DNA repair pathways, has experienced selection along the branch separating Cnidaria and Bilateria. Transcriptome wide screens of paralog groups and transition/transversion ratios highlighted genes including: green fluorescent proteins, carbonic anhydrase, and oxidative stress proteins; and functional groups involved in protein and nucleic acid metabolism, and the formation of structural molecules. These results provide a starting point for study of adaptive evolution in corals. CONCLUSIONS: Currently available transcriptome data now make comparative studies of the mechanisms underlying coral's evolutionary success possible. Here we identified candidate genes that enable corals to maintain genomic integrity despite considerable exposure to genotoxic stress over long life spans, and showed conservation of important physiological pathways between corals and bilaterians

Prednisolone combined with adjunctive immunosuppression is not superior to prednisolone alone in terms of efficacy and safety in giant cell arteritis:meta-analysis

To conduct a meta-analysis of published data of the effectiveness of drug treatment in giant cell arteritis (GCA) to provide evidence to support the optimal use of glucocorticoids (GCs) and adjunct therapy. MEDLINE, CENTRAL and EMBASE searches were used to identify randomised control trials on the treatment of GCA. Studies included were trials in which: (1) the participants were classified as having GCA by the 1990 ACR criteria or biopsy proven disease; (2) parallel-group randomised control of at least 16 weeks duration had been conducted with at least 20 participants; (3) the design included either alternative adjunct immunosuppressant regimens, alternative GCs dosing or routes of administration; and (4) outcome data was included on either relapse rates or rates of infection. One thousand eight hundred thirty-six articles were retrieved, of which only 37 met the primary inclusion criteria. Sixteen of these studies reported some information about the GCs or adjuvant regimen used. Only ten studies were of sufficient quality to be included in the meta-analysis. Together these comprised 638 participants of which 72 % were female. Three studies compared various GCs regimens, with two comparing IV GCs, the latter showing a marginal benefit with respect to relapse (risk ratio (RR) = 0.78, 95 % CI = 0.54 to 1.12) but a greater risk of infection (RR = 1.58, 95 % CI = 0.90 to 2.78). Another three used methotrexate as an adjunctive agent and showed marginal benefit with respect to relapse (RR = 0.85, 95 % CI = 0.66 to 1.11). The remaining four trials compared prednisolone to dapsone, infliximab, adalimumab and hydroxychloroquine, respectively. There are various clinical trials of varying quality. The results from this meta-analysis show that the use of adjunct agents is not associated with improved outcome