To elucidate host processes and components required for the sustained growth and reproduction of the obligate biotrophic fungus Golovinomyces orontii on Arabidopsis thaliana , laser microdissection was used to isolate cells at the site of infection at 5 days postinfection for downstream global Arabidopsis expression profiling. Site-specific profiling increased sensitivity dramatically, allowing us to identify specific host processes, process components, and their putative regulators hidden in previous whole-leaf global expression analyses. For example, 67 transcription factors exhibited altered expression at the powdery mildew (PM) infection site, with subsets of these playing known or inferred roles in photosynthesis, cold/dehydration responses, defense, auxin signaling, and the cell cycle. Using integrated informatics analyses, we constructed putative regulatory networks for a subset of these processes and provided strong support for host cell cycle modulation at the PM infection site. Further experimentation revealed induced host endoreduplication occurred exclusively at the infection site and led us to identify MYB3R4 as a transcriptional regulator of this process. Induced endoreduplication was abrogated in myb3r4 mutants, and G. orontii growth and reproduction were reduced. This suggests that, by increasing gene copy number, localized endoreduplication serves as a mechanism to meet the enhanced metabolic demands imposed by the fungus, which acquires all its nutrients from the plant host.
BackgroundSelective patient recruitment can produce discrepancies between clinical trial results and real-world effectiveness.MethodsA systematic literature review and meta-analysis were conducted to assess vedolizumab real-world effectiveness and safety in patients with ulcerative colitis (UC) or Crohn’s disease (CD). MEDLINE, MEDLINE In-Process, EMBASE, and Cochrane databases were searched for real-world studies of vedolizumab in adult patients with UC/CD reporting clinical response, remission, corticosteroid-free remission, UC/CD-related surgery or hospitalization, mucosal healing, or safety published from May 1, 2014–June 22, 2017. Response and remission rates were combined in random-effects meta-analyses.ResultsAt treatment week 14, 32% of UC patients [95% confidence interval (CI) 27–39%] and 30% of CD patients (95% CI 25–34%) were in remission; and at month 12, 46% for UC (95% CI 37–56%) and 30% for CD (95% CI 20–42%). For UC, the rates of corticosteroid-free remission were 26% at week 14 (95% CI 20–34%) and 42% at month 12 (95% CI 31–53%); for CD they were 25% at week 14 (95%, CI 20–31%) and 31% at month 12 (95%, CI 20–45%). At month 12, 33–77% of UC and 6–63% of CD patients had mucosal healing. Nine percent of patients reported serious adverse events.ConclusionsVedolizumab demonstrated real-world effectiveness in patients with moderate-to-severely active UC or CD, with approximately one-half and one-third of patients, respectively, in remission at treatment month 12. These findings are consistent with clinical trial data and support the long-term benefit–risk profile of vedolizumab.Electronic supplementary materialThe online version of this article (10.1007/s00535-018-1480-0) contains supplementary material, which is available to authorized users.
MLN4924 is an investigational small-molecule inhibitor of the NEDD8-activating enzyme (NAE) in phase I clinical trials. NAE inhibition prevents the ubiquitination and proteasomal degradation of substrates for cullin-RING ubiquitin E3 ligases that support cancer pathophysiology, but the genetic determinants conferring sensitivity to NAE inhibition are unknown. To address this gap in knowledge, we conducted a genome-wide siRNA screen to identify genes and pathways that affect the lethality of MLN4924 in melanoma cells. Of the 154 genes identified, approximately one-half interfered with components of the cell cycle, apoptotic machinery, ubiquitin system, and DNA damage response pathways. In particular, genes involved in DNA replication, p53, BRCA1/BRCA2, transcription-coupled repair, and base excision repair seemed to be important for MLN4924 lethality. In contrast, genes within the G 2 -M checkpoint affected sensitivity to MLN4924 in colon cancer cells. Cell-cycle analysis in melanoma cells by flow cytometry following RNAi-mediated silencing showed that MLN4924 prevented the transition of cells from S-G 2 phase after induction of rereplication stress. Our analysis suggested an important role for the p21-dependent intra-S-phase checkpoint and extensive rereplication, whereas the ATR-dependent intra-S-phase checkpoint seemed to play a less dominant role. Unexpectedly, induction of the p21-dependent intra-S-phase checkpoint seemed to be independent of both Cdt1 stabilization and ATR signaling. Collectively, these data enhance our understanding of the mechanisms by which inhibition of NEDD8-dependent ubiquitination causes cell death, informing clinical development of MLN4924. Cancer Res; 73(1); 225-34. Ó2012 AACR.
We assessed the performance of two US Food and Drug Administration ( FDA ) 510(k)‐cleared wearable digital devices and the operational feasibility of deploying them to augment data collection in a 10‐day residential phase I clinical trial. The Phillips Actiwatch Spectrum Pro (Actiwatch) was used to assess mobility and sleep, and the Vitalconnect HealthPatch MD (HealthPatch) was used for monitoring heart rate ( HR ), respiratory rate ( RR ), and surface skin temperature ( ST ). We measured data collection rates, compared device readouts with anticipated readings and conventional in‐clinic measures, investigated data limitations, and assessed user acceptability. Six of nine study participants consented; completeness of data collection was adequate (> 90% for four of six subjects). A good correlation was observed between the HealthPatch device derived and in‐clinic measures for HR (Pearson r = 0.71; P = 2.2e‐16) but this was poor for RR ( r = 0.08; P = 0.44) and ST ( r = 0.14; P = 0.14). Manual review of electrocardiogram strips recorded during reported episodes of tachycardia > 180 beats/min showed that these were artefacts. The HealthPatch was judged to be not fit‐for‐purpose because of artefacts and the need for time‐consuming manual review. The Actiwatch device was suitable for monitoring mobility, collecting derived sleep data, and facilitating the interpretation of vital sign data. These results suggest the need for fit‐for‐purpose evaluation of wearable devices prior to their deployment in drug development studies.
MLN4924 is an investigational small-molecule inhibitor of the Nedd8-activating enzyme currently in phase I clinical trials. MLN4924 induces DNA damage via rereplication in most cell lines. This distinct mechanism of DNA damage may affect its ability to combine with standard-of-care agents and may affect the clinical development of MLN4924. As such, we studied its interaction with other DNA-damaging agents. Mitomycin C, cisplatin, cytarabine, UV radiation, SN-38, and gemcitabine demonstrated synergy in combination with MLN4924 in vitro. The combination of mitomycin C and MLN4924 was shown to be synergistic in a mouse xenograft model. Importantly, depletion of genes within the ataxia telangiectasia and Rad3 related (ATR) and BRCA1/BRCA2 pathways, chromatin modification, and transcription-coupled repair reduced the synergy between mitomycin C and MLN4924. In addition, comet assay demonstrated increased DNA strand breaks with the combination of MLN4924 and mitomycin C. Our data suggest that mitomycin C causes stalled replication forks, which when combined with rereplication induced by MLN4924 results in frequent replication fork collisions, leading to cell death. This study provides a straightforward approach to understand the mechanism of synergy, which may provide useful information for the clinical development of these combinations. Mol Cancer Ther; 13(6); 1625-35. Ó2014 AACR.
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