piRNAs and Aubergine cooperate with Wispy poly(A) polymerase to stabilize mRNAs in the germ plasm

Piwi-interacting RNAs (piRNAs) and PIWI proteins play a crucial role in germ cells by repressing transposable elements and regulating gene expression. In Drosophila, maternal piRNAs are loaded into the embryo mostly bound to the PIWI protein Aubergine (Aub). Aub targets maternal mRNAs through incomplete base-pairing with piRNAs and can induce their destabilization in the somatic part of the embryo. Paradoxically, these Aub-dependent unstable mRNAs encode germ cell determinants that are selectively stabilized in the germ plasm. Here we show that piRNAs and Aub actively protect germ cell mRNAs in the germ plasm. Aub directly interacts with the germline-specific poly(A) polymerase Wispy, thus leading to mRNA polyadenylation and stabilization in the germ plasm. These results reveal a role for piRNAs in mRNA stabilization and identify Aub as an interactor of Wispy for mRNA polyadenylation. They further highlight the role of Aub and piRNAs in embryonic patterning through two opposite functions

Colorectal Cancer Stem Cells Are Enriched in Xenogeneic Tumors Following Chemotherapy

Patients generally die of cancer after the failure of current therapies to eliminate residual disease. A subpopulation of tumor cells, termed cancer stem cells (CSC), appears uniquely able to fuel the growth of phenotypically and histologically diverse tumors. It has been proposed, therefore, that failure to effectively treat cancer may in part be due to preferential resistance of these CSC to chemotherapeutic agents. The subpopulation of human colorectal tumor cells with an ESA(+)CD44(+) phenotype are uniquely responsible for tumorigenesis and have the capacity to generate heterogeneous tumors in a xenograft setting (i.e. CoCSC). We hypothesized that if non-tumorigenic cells are more susceptible to chemotherapeutic agents, then residual tumors might be expected to contain a higher frequency of CoCSC.Xenogeneic tumors initiated with CoCSC were allowed to reach approximately 400 mm(3), at which point mice were randomized and chemotherapeutic regimens involving cyclophosphamide or Irinotecan were initiated. Data from individual tumor phenotypic analysis and serial transplants performed in limiting dilution show that residual tumors are enriched for cells with the CoCSC phenotype and have increased tumorigenic cell frequency. Moreover, the inherent ability of residual CoCSC to generate tumors appears preserved. Aldehyde dehydrogenase 1 gene expression and enzymatic activity are elevated in CoCSC and using an in vitro culture system that maintains CoCSC as demonstrated by serial transplants and lentiviral marking of single cell-derived clones, we further show that ALDH1 enzymatic activity is a major mediator of resistance to cyclophosphamide: a classical chemotherapeutic agent.CoCSC are enriched in colon tumors following chemotherapy and remain capable of rapidly regenerating tumors from which they originated. By focusing on the biology of CoCSC, major resistance mechanisms to specific chemotherapeutic agents can be attributed to specific genes, thereby suggesting avenues for improving cancer therapy

Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial.

Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions: The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108). Main Outcomes and Measures: The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results: After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance: Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT02735707

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

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

Ca and Co Substitutions in (Ca,Co)(OH)2 Hydroxides

International audienceAccording to DFT simulation, no mixed hydroxide containing calcium and a small divalent cation with the brucite structure is possible. This experimental study confirms that between portlandite (Ca(OH)2) and b-Co(OH)2, a solid solution does not exist. Samples have been synthesized by coprecipitation under flowing nitrogen at room temperature. However, XRD, TEM and DTA/TG analyses show that a partial solubility exists and that the substitution limit of calcium in b-Co(OH)2 is lower than 12% and lower than 7% for cobalt in Ca(OH)2. The two kinds of particles exhibit similar plate-like morphology with a size between 50 and 200 nm and a thickness of about 10 nm. The origin of such low substitution limits could be the difference in radii between calcium and cobalt generating local stresses. Substitutions by small amounts of different cations to reduce the local stresses such as Al, Sr or Cu have failed to allow improving significantly the substitution limits. An alternative synthesis route consisting in contacting the first cation oxide in a solution containing a salt of the second cation has also failed to reach a complete solid solution between portlandite and b-Co(OH)2

Synthesis of manganese spinel nanoparticles at room temperature by coprecipitation

International audienceThis paper is focused on a new route to synthesize Mn3O4 nanoparticles by alkalisation by sodium hydroxide on a manganeous solution at room temperature. The precipitates obtained at different pH values have been characterized by XRD and TEM. Since the first addition of sodium hydroxide, a white Mn(OH)2 precipitate appears. At pH=7, γ-MnOOH phase is predominant with needle like shaped particles. At pH=10, hausmanite nanoparticles, which exhibits well defined cubic shape in the range 50-120 nm are obtained. This new precipitation route is a fast and easy environmentally friendly process to obtain well crystallized hausmanite nanoparticles

Expansion and Characterization of Iovance Marrow Infiltrating Lymphocytes: A Potential Novel Therapeutic Strategy for the Treatment of Acute Myeloid Leukemia

Abstract Background: Acute myeloid leukemia (AML) is a poor-prognosis malignancy arising from hematopoietic stem/progenitor cells. To date, novel immunotherapies such as checkpoint inhibitors, vaccines and adoptive cell therapy (ACT) using CAR T cells have demonstrated only modest success for the treatment of patients who are ineligible for marrow transplantation and have minimal residual disease; additional approaches are warranted (Beyar-Katz O and Gill S, Clin Cancer Res 2018). ACT with tumor infiltrating lymphocytes (TIL) has emerged as an effective treatment for patients with metastatic melanoma (Goff SL et al, J Clin Oncol 2016), likely owing to the heterogeneous population of tumor-reactive T cells that comprises the TIL products. As demonstrated for solid cancers, such tumor-reactive T cells are preferentially found in the tumor microenvironment (Gros A et al JCI 2014; Thommen DS et al Nat Med 2018). By avoiding the highly immunosuppressive tumor microenvironment, ex vivo activation of those cells rescues them from tolerance and anergic status. We hypothesized that, in the case of AML for which the bone marrow represents the tumor microenvironment, tumor antigen-specific T cells could be recovered from the patient bone marrow to produce a highly effective therapeutic product that is cytotoxic to AML tumor cells. We present findings related to the ex vivo expansion of Iovance marrow infiltrating lymphocytes (MIL) for the treatment of AML patients. Methods: Immune cell and non-immune cell fractions were sorted from bone marrow mononuclear cells. Immune cell fractions loaded with sonicated non-immune cell fractions were expanded for 14 days in the presence of αCD3/αCD28 beads and interleukin-2 (IL-2) to generate MIL products. Phenotypic and functional characteristics of the cells were determined by flow cytometry and enzyme-linked immunospot assay (ELISpot). Results: MIL were generated from isolated bone marrow mononuclear cells (n=2) with a mean expansion fold of 86 (range 78-93). Equal percentage of CD4+ and CD8+ T cell subsets constituted the MIL products. Phenotypic analysis of the cells showed that the majority of T cell subsets are effector memory and CD28 positive. Low percentages of the T cell subsets were positive for immunosuppressive markers PD-1 and LAG3. ELISpot analysis demonstrated that MIL were readily activatable and produced normal levels of IFNγ in response to CD3/CD28 stimulation. Antigen specificity of MIL is being investigated. Conclusion: We demonstrated the feasibility of MIL expansion from bone marrow mononuclear cells from AML patients. MIL are functionally active and mostly comprised of effector memory T cells. Confirmation of tumor cell antigen specificity will determine whether MIL may deploy a robust anti-tumor activity in vivo. Disclosures Karyampudi: Iovance Biotherapeutics: Employment, Equity Ownership. Frank:Iovance Biotherapeutics: Employment, Equity Ownership. Blaskovich:Iovance Biotherapeutics: Equity Ownership. Chartier:Iovance Biotherapeutics: Equity Ownership. </jats:sec