7 research outputs found

    Nutlin-3a efficacy in sarcoma predicted by transcriptomic and epigenetic profiling

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    Nutlin-3a is a small-molecule antagonist of p53/MDM2 that is being explored as a treatment for sarcoma. In this study, we examined the molecular mechanisms underlying the sensitivity of sarcomas to Nutlin-3a. In an ex vivo tissue explant system, we found that TP53 pathway alterations (TP53 status, MDM2/MDM4 genomic amplification/mRNA overexpression, MDM2 SNP309, and TP53 SNP72) did not confer apoptotic or cytostatic responses in sarcoma tissue biopsies (n = 24). Unexpectedly, MDM2 status did not predict Nutlin-3a sensitivity. RNA sequencing revealed that the global transcriptomic profiles of these sarcomas provided a more robust prediction of apoptotic responses to Nutlin-3a. Expression profiling revealed a subset of TP53 target genes that were transactivated specifically in sarcomas that were highly sensitive to Nutlin-3a. Of these target genes, the GADD45A promoter region was shown to be hypermethylated in 82% of wild-type TP53 sarcomas that did not respond to Nutlin-3a, thereby providing mechanistic insight into the innate ability of sarcomas to resist apoptotic death following Nutlin-3a treatment. Collectively, our findings argue that the existing benchmark biomarker for MDM2 antagonist efficacy (MDM2 amplification) should not be used to predict outcome but rather global gene expression profiles and epigenetic status of sarcomas dictate their sensitivity to p53/MDM2 antagonists.Kathleen I. Pishas, Susan J. Neuhaus, Mark T. Clayer, Andreas W. Schreiber, David M. Lawrence, Michelle Perugini, Robert J. Whitfield, Gelareh Farshid, Jim Manavis, Steve Chryssidis, Bronwen J. Mayo, Rebecca C. Haycox, Kristen Ho, Michael P. Brown, Richard J. D'Andrea, Andreas Evdokiou, David M. Thomas, Jayesh Desai, David F. Callen and Paul M. Neilse

    CT findings in patients with Cabazitaxel induced pelvic pain and haematuria: a case series

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    Abstract Background Haematuria and pelvic pain are recognized and documented adverse reactions related to Cabazitaxel use. To date there has not been any documentation of imaging findings in patients with this presentation. Cases We report a case series of five patients who experienced these symptoms while on Cabazitaxel and were all found to have very similar urothelial changes on CT. The patients were noted to have ureteric and renal pelvic dilatation along with urothelial enhancement (in those who had post contrast imaging). All of these changes were noted to be reversible in those who had follow up imaging after cessation of Cabazitaxel and initiation of a short course of steroids. Conclusion This case series helps demonstrate the pathological reversible urothelial inflammatory changes that may be occurring in patients experiencing haematuria and pelvic pain on Cabazitaxel therapy. These changes may relate to direct toxic effect of drug metabolites, a radiation recall type phenomenon or a combination of both

    Nutlin-3a efficacy in sarcoma predicted by transcriptomic and epigenetic profiling

    No full text
    Nutlin-3a is a small molecule antagonist of p53/MDM2 that is being explored as a treatment for sarcoma. In this study, we examined the molecular mechanisms underlying the sensitivity of sarcomas to Nutlin-3a. In an ex vivo tissue explant system, we found that TP53 pathway alterations (TP53 status, MDM2/MDM4 genomic amplification/mRNA overexpression, MDM2 SNP309, and TP53 SNP72) didn't confer apoptotic or cytostatic responses in sarcoma tissue biopsies (n=24). Unexpectedly, MDM2 status didn't predict Nutlin-3a sensitivity. RNA sequencing revealed that the global transcriptomic profiles of these sarcomas provided a more robust prediction of apoptotic responses to Nutlin-3a. Expression profiling revealed a subset of TP53 target genes which were transactivated specifically in sarcomas that were highly sensitive to Nutlin-3a. Of these target genes, the GADD45A promoter region was shown to be hypermethylated in 82% of wild-type TP53 sarcomas that didn't respond to Nutlin-3a, thereby providing mechanistic insight into the innate ability of sarcomas to resist apoptotic death following Nutlin-3a treatment. Collectively, our findings argue that the existing benchmark biomarker for MDM2 antagonist efficacy (MDM2 amplification) should not be used to predict outcome, but rather global gene expression profiles and epigenetic status of sarcomas dictate their sensitivity to p53/MDM2 antagonists.

    A multicenter, randomized, controlled study to investigate extending the time for thrombolysis in emergency neurological deficits with intra-arterial therapy (EXTEND-IA)

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    Background and Hypothesis: Thrombolysis with tissue plasminogen activator is proven to reduce disability when given within 4·5h of ischemic stroke onset. However, tissue plasminogen activator only succeeds in recanalizing large vessel arterial occlusion in a minority of patients. We hypothesized that anterior circulation ischemic stroke patients, selected with 'dual target' vessel occlusion and evidence of salvageable brain using computed tomography or magnetic resonance imaging 'mismatch' within 4·5h of onset, would have improved reperfusion and early neurological improvement when treated with intra-arterial clot retrieval after intravenous tissue plasminogen activator compared with intravenous tissue plasminogen activator alone. Study Design: EXTEND-IA is an investigator-initiated, phase II, multicenter prospective, randomized, open-label, blinded-endpoint study. Ischemic stroke patients receiving standard 0·9mg/kg intravenous tissue plasminogen activator within 4·5h of stroke onset who have good prestroke functional status (modified Rankin Scale 1·2, absolute mismatch >10ml, ischemic core volum

    World Federation of Interventional and Therapeutic Neuroradiology (WFITN) Federation Assembly neurointerventional surgery safety checklist

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    Over the last 10 years, there has been a rise in neurointerventional case complexity, device variety and physician distractions. Even among experienced physicians, this trend challenges our memory and concentration, making it more difficult to remember safety principles and their implications. Checklists are regarded by some as a redundant exercise that wastes time, or as an attack on physician autonomy. However, given the increasing case and disease complexity along with the number of distractions, it is even more important now to have a compelling reminder of safety principles that preserve habits that are susceptible to being overlooked because they seem mundane. Most hospitals have mandated a pre-procedure neurointerventional time-out checklist, but often it ends up being done in a cursory fashion for the primary purpose of ‘checking off boxes’. There may be value in iterating the checklist to further emphasize safety and communication. The Federation Assembly of the World Federation of Interventional and Therapeutic Neuroradiology (WFITN) decided to construct a checklist for neurointerventional cases based on a review of the literature and insights from an expert panel
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