26 research outputs found

    Phase II study of the dual EGFR/HER3 inhibitor duligotuzumab (MEHD7945A) vs. cetuximab in combination with FOLFIRI in RAS wild-type metastatic colorectal cancer

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    PURPOSE: Duligotuzumab is a dual-action antibody directed against EGFR and HER3. EXPERIMENTAL DESIGN: mCRC patients with KRAS ex2 wild-type received duligotuzumab or cetuximab and FOLFIRI until progression or intolerable toxicity. Mandatory tumor samples underwent mutation and biomarker analysis. Efficacy analysis was conducted in patients with RAS exon 2/3 wild-type tumors. RESULTS: Of 134 randomized patients, 98 were RAS ex2/3 wild-type. Duligotuzumab provided no PFS or OR benefit compared to cetuximab; though there was a trend for lower ORR in the duligotuzumab arm. No relationship was seen between PFS or ORR and ERBB3, NRG1, or AREG expression. There were fewer skin rash events for duligotuzumab but more diarrhea. Although the incidence of grade ≥ 3 AEs was similar, the frequency of serious AEs was higher for duligotuzumab. CONCLUSIONS: Duligotuzumab plus FOLFIRI did not appear to improve the outcomes in patients with RAS exon 2/3 wild-type mCRC compared to cetuximab + FOLFIRI

    LOSS OF JAK2 REGULATION VIA VHL-SOCS1 E3 UBIQUITIN HETEROCOMPLEX UNDERLIES CHUVASH POLYCYTHEMIA

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    Chuvash polycythemia (CP) is a rare congenital form of polycythemia caused by homozygous R200W and H191D mutations in the von Hippel-Lindau (VHL) gene whose gene product is the principal negative regulator of hypoxia-inducible factor. However, the molecular mechanisms underlying some of the hallmark features of CP such as hypersensitivity to erythropoietin are unclear. Here, we show that VHL directly binds suppressor of cytokine signalling 1 (SOCS1) to form a heterodimeric E3 ligase that targets phosphorylated (p)JAK2 for ubiquitin-mediated destruction. In contrast, CP-associated VHL mutants have altered affinity for SOCS1 and fail to engage and degrade pJAK2. Systemic administration of a highly selective JAK2 inhibitor, TG101209, reverses the disease phenotype in vhlR200W/R200W knock-in mice, a model that faithfully recapitulates human CP. These results reveal VHL as a SOCS1-cooperative negative regulator of JAK2 and provide compelling biochemical and preclinical evidence for JAK2- targeted therapy in CP patients

    The structure and regulation of Cullin 2 based E3 ubiquitin ligases and their biological functions

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    Atezolizumab plus Bevacizumab Versus Sunitinib for Patients with Untreated Metastatic Renal Cell Carcinoma and Sarcomatoid Features: A Prespecified Subgroup Analysis of the IMmotion151 Clinical Trial

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    Patients with metastatic renal cell carcinoma with sarcomatoid features (sRCC) have a poor prognosis and have shown limited responsiveness to inhibition of the VEGF pathway. We conducted a prespecified analysis of the randomised, phase 3 IMmotion151 trial in previously untreated patients with advanced or metastatic RCC to assess the effectiveness of atezolizumab + bevacizumab versus sunitinib in a subgroup of patients with sarcomatoid features. Patients whose tumour had any component of sarcomatoid features were included and received atezolizumab + bevacizumab (n = 68) or sunitinib (n = 74). Baseline characteristics were similar between the groups. Median progression-free survival was significantly longer in the group receiving atezolizumab + bevacizumab overall (8.3 vs 5.3 mo; hazard ratio [HR] 0.52 95% confidence interval [CI] 0.34–0.79) and in the subset of patients with PD-L1–positive tumours (8.6 vs 5.6 mo; HR 0.45, 95% CI 0.26–0.77). More patients receiving atezolizumab + bevacizumab achieved an objective response (49% vs 14%), including complete responses (10% vs 3%), and reported greater symptom improvements versus sunitinib. Safety was consistent with the known profiles of each drug and with that reported in the overall safety-evaluable population of IMmotion151. This analysis supports enhanced activity of atezolizumab + bevacizumab in patients with sRCC. Patient summary: In this report, we looked at patients with a specific type of kidney cancer (tumours with sarcomatoid features) that has been hard to treat. A treatment with two drugs (atezolizumab and bevacizumab) appeared to help patients live longer without the disease getting worse than another drug (sunitinib) that is often used. Patients who took the two drugs also said they were better able to carry out their everyday activities than patients who took sunitinib. The combination of these two drugs may work better in patients with this type of advanced kidney cancer

    VHL Promotes E2 Box-Dependent E-Cadherin Transcription by HIF-Mediated Regulation of SIP1 and Snail

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    The product of the von Hippel-Lindau gene (VHL) acts as the substrate-recognition component of an E3 ubiquitin ligase complex that ubiquitylates the catalytic α subunit of hypoxia-inducible factor (HIF) for oxygen-dependent destruction. Although emerging evidence supports the notion that deregulated accumulation of HIF upon the loss of VHL is crucial for the development of clear-cell renal cell carcinoma (CC-RCC), the molecular events downstream of HIF governing renal oncogenesis remain unclear. Here, we show that the expression of a homophilic adhesion molecule, E-cadherin, a major constituent of epithelial cell junctions whose loss is associated with the progression of epithelial cancers, is significantly down-regulated in primary CC-RCC and CC-RCC cell lines devoid of VHL. Reintroduction of wild-type VHL in CC-RCC (VHL(−/−)) cells markedly reduced the expression of E2 box-dependent E-cadherin-specific transcriptional repressors Snail and SIP1 and concomitantly restored E-cadherin expression. RNA interference-mediated knockdown of HIFα in CC-RCC (VHL(−/−)) cells likewise increased E-cadherin expression, while functional hypoxia or expression of VHL mutants incapable of promoting HIFα degradation attenuated E-cadherin expression, correlating with the disengagement of RNA polymerase II from the endogenous E-cadherin promoter/gene. These findings reveal a critical HIF-dependent molecular pathway connecting VHL, an established “gatekeeper” of the renal epithelium, with a major epithelial tumor suppressor, E-cadherin

    Cuidados generales en el manejo del traumatismo craneoencefálico grave: consenso latinoamericano

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    Severe traumatic brain injury (sTBI) remains prevalent in the young adult population. Indeed, far from descending, the incidence of sTBI remains high. One of the key bases of treatment is to avoid, detect and correct secondary injuries of systemic origin, which aggravate the primary lesion. Much of this can be achieved by maintaining an adequate physiological microenvironment allowing recovery of the damaged brain tissue. General care measures are nonspecific actions designed to meet that objective. The available guidelines on the management of sTBI have not included the topics contemplated in this consensus. In this regard, a group of members of the Latin American Brain Injury Consortium (LABIC), involved in the different aspects of the acute management of sTBI (neurosurgeons, intensivists, anesthesiologists, neurologists, nurses and physiotherapists) were gathered. An exhaustive literature search was made of selected topics in the LILACS, PubMed, Embase, Scopus, Cochrane Controlled Register of Trials and Web of Science databases. To establish recommendations or suggestions with their respective strength or weakness, the GRADE methodology (Grading of Recommendations, Assessment, Development and Evaluation) was applied. Additionally, certain recommendations (included in complementary material) were not assessed by GRADE, because they constitute a set of therapeutic actions of effective compliance, in which it was not possible to apply the said methodology. Thirty-two recommendations were established, 16 strong and 16 weak, with their respective levels of evidence. This consensus attempts to standardize and establish basic general care measures in this particular patient population. © 2020 Elsevier España, S.L.U. y SEMICYU

    General care in the management of severe traumatic brain injury: Latin American consensus.

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    Severe traumatic brain injury (sTBI) remains prevalent in the young adult population. Indeed, far from descending, the incidence of sTBI remains high. One of the key bases of treatment is to avoid, detect and correct secondary injuries of systemic origin, which aggravate the primary lesion. Much of this can be achieved by maintaining an adequate physiological microenvironment allowing recovery of the damaged brain tissue. General care measures are nonspecific actions designed to meet that objective. The available guidelines on the management of sTBI have not included the topics contemplated in this consensus. In this regard, a group of members of the Latin American Brain Injury Consortium (LABIC), involved in the different aspects of the acute management of sTBI (neurosurgeons, intensivists, anesthesiologists, neurologists, nurses and physiotherapists) were gathered. An exhaustive literature search was made of selected topics in the LILACS, PubMed, Embase, Scopus, Cochrane Controlled Register of Trials and Web of Science databases. To establish recommendations or suggestions with their respective strength or weakness, the GRADE methodology (Grading of Recommendations, Assessment, Development and Evaluation) was applied. Additionally, certain recommendations (included in complementary material) were not assessed by GRADE, because they constitute a set of therapeutic actions of effective compliance, in which it was not possible to apply the said methodology. Thirty-two recommendations were established, 16 strong and 16 weak, with their respective levels of evidence. This consensus attempts to standardize and establish basic general care measures in this particular patient population
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