15 research outputs found

    Tumor Antigen Acrosin Binding Protein Normalizes Mitotic Spindle Function to Promote Cancer Cell Proliferation

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    Cancer cells manage to divide in the context of gross chromosomal abnormalities. These abnormalities can promote bypass of normal restraints on cell proliferation, but at a cost of mitotic vulnerabilities that can be attacked by chemotherapy. Determining how cancer cells balance these issues may permit chemotherapeutic sensitivity to be leveraged more efficiently. From a pan-genomic siRNA screen for modifiers of chemoresponsiveness, we identified the tumor antigen ACRBP/OY-TES-1 as a specifier of paclitaxel resistance. ACRBP expression is normally restricted to the testes but detected in a wide variety of cancers, including most ovarian cancers. We found that ACRBP is both necessary and sufficient for paclitaxel resistance in ovarian cancer cell lines and ovarian tumor explants. Moreover, high ACRBP expression correlated with reduced survival time and faster relapse among ovarian cancer patients. We identified the mitotic spindle protein NuMA as an ACRBP-interacting protein that could account for the effects of ACRBP on paclitaxel sensitivity. In cancer cells, ACRBP restricted a NuMA-dependent abrogation of mitotic spindle assembly that is otherwise pathologic. As a consequence, ACRBP depletion resulted in mitotic errors and reduced proliferative fitness that could be rescued by NuMA co-depletion. We propose that the co-dependent relationship of ACRBP and NuMA in cancer cells reflects their passage through a selection bottleneck during tumor evolution, one which requires the acquisition of traits which normalize mitotic perturbations that originally drove the plasticity of a pre-neoplastic genome. The molecular definition of such traits as defined by the ACRBP-NuMA complex may represent conceptually ideal intervention targets, based on the wide therapeutic windows they may offer

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

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    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

    Historical Survey on Chromatoid Body Research

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    Proteomic analysis of murine Piwi proteins reveals a role for arginine methylation in specifying interaction with Tudor family members

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    In germ cells, Piwi proteins interact with a specific class of small noncoding RNAs, piwi-interacting RNAs (piRNAs). Together, these form a pathway that represses transposable elements, thus safeguarding germ cell genomes. Basic models describe the overall operation of piRNA pathways. However, the protein compositions of Piwi complexes, the critical protein–protein interactions that drive small RNA production and target recognition, and the precise molecular consequences of conserved localization to germline structures, call nuage, remains poorly understood. We purified the three murine Piwi family proteins, MILI, MIWI, and MIWI2, from mouse germ cells and characterized their interacting protein partners. Piwi proteins were found in complex with PRMT5/WDR77, an enzyme that dimethylates arginine residues. By immunoprecipitation with specific antibodies and by mass spectrometry, we found that Piwi proteins are arginine methylated at conserved positions in their N termini. These modifications are essential to direct complex formation with specific members of the Tudor protein family. Recognition of methylarginine marks by Tudor proteins can drive the localization of Piwi proteins to cytoplasmic foci in an artificial setting, supporting a role for this interaction in Piwi localization to nuage, a characteristic that correlates with proper operation of the piRNA pathway and transposon silencing in multiple organisms

    Aortic stiffness aging is influenced by past profound immunodeficiency in HIV-infected individuals: Results from the EVAS-HIV (EValuation of Aortic Stiffness in HIV-infected individuals)

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    Objective: We compared aortic stiffness between HIV-infected and HIV-uninfected individuals and examined the determinants of vascular aging during HIV infection. Methods: Aortic stiffness using carotid-femoral pulse wave velocity (cf-PWV) was evaluated cross-sectionally between HIV-infected individuals and uninfected controls frequency-matched for age and sex, and longitudinally in a subgroup of HIV-infected individuals. Determinants of elevated cf-PWV levels were assessed using logistic regression. Changes in cf-PWV levels during follow-up (mixed-effect linear regression) and risk factors for achieving cf-PWV below (Group 1) or above the median (Group 2) at last follow-up visit were evaluated only in HIV-infected individuals. Results: A total of 133 HIV-infected and 135 HIV-uninfected individuals (mean age: 47.7±8.9 years, 91% men) were enrolled. Median cf-PWV at baseline was similar between HIV-infected individuals and controls [7.5m/s (interquartile range=6.7-8.4) vs. 7.5m/s (interquartile range=6.6-8.4), respectively; P=0.64]. In multivariable analysis, only mean arterial pressure showed significant association with elevated cf-PWV in the overall population (P=0.036). In HIV-infected individuals, elevated cf-PWV was associated with current smoking (P=0.042), and nadir CD4 + T-cell count less than 200 cells/μl (P=0.048). Ninety-one HIV-infected individuals were followed for a mean 7.6±2.0 years. cf-PWV progression was associated with age (P=0.018), mean arterial pressure (P=0.020), and nadir CD4 + T-cell count (P=0.005). Patients from Group 2 had higher baseline waist circumference, pulse pressure, and nadir CD4 + T-cell count less than 200 cells/μl. Conclusion: We observed no difference in aortic stiffness between HIV-infected and controls. Moreover, aortic stiffness aging was independently associated with past severe immunodeficiency, along with other traditional risk factors. Our results call for early antiretroviral initiation.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
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