Esperanza Muñoz-Muela

Background: New nucleos(t)ide reverse transcriptase inhibitors are considerably less toxic than their predecessors, but they may not be entirely devoid of toxicity. However, their effect in healthy adults remains unknown. We aimed to analyze the impact of tenofovir disoproxil fumarate plus emtricitabine (TDF/FTC)–based preexposure prophylaxis (PrEP) on mitochondria of subjects at high risk of human immunodeficiency virus type 1 infection. Methods: This was an observational, prospective study of 59 healthy adults enrolled in the PrEP program at Virgen del Rocío University Hospital. Mitochondrial DNA and common deletion 4977 were measured using digital droplet polymerase chain reaction. Mitochondrial density, membrane potential, oxidative stress, metabolic profile, and morphology were assessed by flow cytometry, real-time cellular bioenergetics measurements, and transmission electron microscopy, respectively, at baseline and after 12 months. Values were compared by the Wilcoxon test, and correlations between variables were assessed using the Spearman rank correlation coefficient (ρ). Results: Our results showed that after 12 months, TDF/FTC induced a mitochondrial oxidative stress increase in myeloid and lymphoid populations. Mitochondrial density decreased in CD8+ T cells and natural killer cells, while mitochondrial membrane potential was augmented in all lymphoid populations. Cell bioenergetic health was compromised, evidenced by reduced oxygen consumption rate, declined adenosine triphosphate production, and impaired response capacity to an energetic demand. Changes in the shape, membrane integrity, cristae structure, size, and distribution of the mitochondria throughout the cytoplasm were also observed. All participants experienced alterations in 1 or more measured parameters. Conclusions: TDF/FTC-based PrEP induces mitochondrial toxicity in healthy subjects after 12 months of treatment, negatively affecting mitochondrial function and morphology.

Viral and host immune kinetics during acute COVID-19 and after remission of acute symptoms need better characterization. SARS-CoV-2 RNA, anti-SARS-CoV-2 IgA, IgM, and IgG antibodies, and proinflammatory cytokines were measured in sequential samples from hospitalized COVID-19 patients during acute infection and six months following diagnosis. Twenty four laboratory confirmed COVID-19 patients with mild/moderate and severe COVID-19 were included. Most were males (83%) with a median age of 61 years. Twenty one percent were admitted to the intensive care unit (ICU) and eight of them (33.3%) met the criteria for severe COVID-19 disease. A delay in SARS-CoV-2 levels’ decline during the first six days of follow up, and viral load persistence until month 3 were related to severe COVID-19, but not viral load levels at the diagnosis. Higher levels of anti-SARS-CoV-2 IgA, IgM, IgG and the cytokines IL-6, IL-8 and MIP-1β at the diagnosis time were related to the severe COVID-19 outcome. Higher levels of MIP-1β, IL-1β, MIP-1α and IFN-γ were observed at month 1 and 3 during mild/moderate disease, compared to severe COVID-19. IgG persisted at low levels after six months of diagnosis. In conclusion, higher concentrations of IgA, IgM, and IgG, and IL-6, IL-8 and MIP-1β are identified as early predictors of COVID-19 severity, whereas no significant association is found between baseline SARS-COV-2 viral load and COVID-19 severity.

This study was aimed to determine the impact of hydroxytyrosol (HT), a minor compound found in olive oil, on breast cancer stem cells (BCSCs) and the migration capacity of triple-negative breast cancer (TNBC) cell lines through the alteration of epithelial-to-mesenchymal transition (EMT) and embryonic signaling pathways.

Purpose: On the basis of the identified stress-independent cellular functions of activating transcription factor 4 (ATF4), we reported enhanced ATF4 levels in MCF10A cells treated with TGFβ1. ATF4 is overexpressed in patients with triple-negative breast cancer (TNBC), but its impact on patient survival and the underlying mechanisms remain unknown. We aimed to determine ATF4 effects on patients with breast cancer survival and TNBC aggressiveness, and the relationships between TGFβ and ATF4. Defining the signaling pathways may help us identify a cell signaling–tailored gene signature. Experimental Design: Patient survival data were determined by Kaplan–Meier analysis. Relationship between TGFβ and ATF4, their effects on aggressiveness (tumor proliferation, metastasis, and stemness), and the underlying pathways were analyzed in three TNBC cell lines and in vivo using patient-derived xenografts (PDX). Results: ATF4 overexpression correlated with TNBC patient survival decrease and a SMAD-dependent crosstalk between ATF4 and TGFβ was identified. ATF4 expression inhibition reduced migration, invasiveness, mammosphere-forming efficiency, proliferation, epithelial–mesenchymal transition, and antiapoptotic and stemness marker levels. In PDX models, ATF4 silencing decreased metastases, tumor growth, and relapse after chemotherapy. ATF4 was shown to be active downstream of SMAD2/3/4 and mTORC2, regulating TGFβ/SMAD and mTOR/RAC1–RHOA pathways independently of stress. We defined an eight-gene signature with prognostic potential, altered in 45% of 2,509 patients with breast cancer. Conclusions: ATF4 may represent a valuable prognostic biomarker and therapeutic target in patients with TNBC, and we identified a cell signaling pathway–based gene signature that may contribute to the development of combinatorial targeted therapies for breast cancer. Clin Cancer Res; 24(22); 5697–709. ©2018 AACR.