Protein-ligand complex for structure-based design: impact on the affinity and antitumor activity of new tubulin ligands

Resumen del trabajo presentado en el XVIII Congreso de la Sociedad Española de Química Terapéutica, celebrado en Salamanca (España), del 23 al 26 de enero de 2018Microtubules, made of ¿ß¿tubulin heterodimers, are the key components of the cytoskeleton and play a crucial role in many cellular processes, such as cell motility, morphogenesis and mitosis.[1] Interference with microtubule dynamics induces cell cycle arrest during mitosis and triggers cell death. Compounds that interact with tubulin, especially those binding at the colchicine domain, have been deeply investigated as anticancer drugs due to their dual mechanism of action as antimitotics and as vascular disrupting agents.[2,3] Our research group has recently described a new family of colchicine¿domain binders, based on a cyclohexanedione skeleton, with potent antiproliferative activity against tumor and endothelial cells.[4] Moreover, to gain insight into the binding mode of these cyclohexanediones, we have determined the crystal structure of ¿ß¿tubulin in complex with our hit compound (TUB075). Based on this detailed information and by applying the affinity maps program cGRILL, a structurebased synthesis of new cyclohexanedione derivatives has been accomplished with the objective of improving their affinity for tubulin and their antitumor activity. Following this approach, we have obtained new compounds with potent antiproliferative activity against tumor and endothelial cells (IC50=8¿31 nM) and with the highest Kb value reported for compounds binding at the colchicine site in tubulin. Additional studies have shown that they arrest cell cycle at G2/M and disrupt a network of endothelial cells. Moreover they keep antiproliferative activity against cell lines overexpressing P¿gp, further supporting the potential of these compounds.The financial support of the Spanish MINECO (SAF2012‐39760‐C02‐01 and SAF 2015‐64629‐C2‐1‐R), Comunidad de Madrid (BIPEDD2; ref P2010/BMD‐2457) and the COST action CM1407 (to M J. P.P., S.L., M.O.S. and J.F.D.) is sincerely acknowledge

Chemical modulation of microtubule structure as a tool to target different diseases

1 p.-1 fig.Microtubules are dynamic filaments involved in many essential cellular functions including those needed for cancer cell growth. Taxanes are microtubule stabilizing agents and the most successful antitumoral drugs targeting these filaments. However, despite their mode of action is the stabilization (i.e., do not destroy the filament structure), they produce a paradoxical neurotoxic effect by inducing axon degeneration. This has been related to microtubule structural modifications upon drug binding. Alternatively, the laulimalide/peloruside binding site also promotes stabilization, but have not been exploits in clinics. We have found that differently to the taxane site, the stabilization mechanism involves exclusively lateral interactions and entails changes on the inter-protofilament angle. Importantly, some compounds do not modify microtubules upon binding when compared to native ones. This feature, together with the low cytotoxicity effect found, open the possibility of exploiting these compounds in neurodegenerative diseases, where microtubule structure and function are compromised due to other primary cellular alterations.Peer reviewe

Crystal structures of taxane-tubulin complexes: Implications for the mechanism of microtubule stabilization by Taxol

30 p.-9 fig.-1 tab.Paclitaxel (Taxol®) is a first-line chemotherapeutic drug that promotes the curved-to-straight conformational transition of tubulin, an activation step that is necessary for microtubule formation. Crystallization of Taxol bound to tubulin has been long elusive. We found that baccatin III, the core structure of paclitaxel which lacks the C13 side chain, readily co-crystallizes with curved tubulin. Tailor-made taxanes with alternative side chains also co-crystallized, allowing us to investigate their binding modes. Interestingly, these Taxol derived compounds lost their microtubule stabilizing activity and cytotoxicity but kept their full microtubule binding affinity, and all induced lattice expansion upon binding. Additional nuclear magnetic resonance studies propose that Taxol binds to a small fraction of straight tubulin present in solution. Our results suggest a mode of action of Taxol, where the core structure is responsible for the interacting energy while the bulky hydrophobic C13 side chain enables binding selectively to straight tubulin and promotes stabilization.N

Definite and indeterminate nonalcoholic steatohepatitis share similar clinical features and prognosis: A longitudinal study of 1893 biopsy-proven nonalcoholic fatty liver disease subjects

[Background and Aim] Histological score systems may not fully capture the essential nonalcoholic steatohepatitis (NASH) features, which is one of the leading causes of screening failure in clinical trials. We assessed the NASH distribution and its components across the fibrosis stages and their impact on the prognosis and their relationship with the concept of metabolic-associated fatty liver disease (MAFLD).[Methods] Spanish multicenter study including 1893 biopsy-proven nonalcoholic fatty liver disease (NAFLD) patients from HEPAmet registry. NASH was diagnosed by NAS score ≥4 (including steatosis, ballooning and lobular inflammation) and fibrosis by Kleiner score. The presence of MAFLD was determined. Progression to cirrhosis, first episode of decompensated cirrhosis and death were collected during the follow-up (4.7 ± 3.8 years).[Results] Fibrosis was F0 34.3% (649/1893), F1 27% (511/1893), F2 16.5% (312/1893), F3 15% (284/1893) and F4 7.2% (137/1893). NASH diagnosis 51.9% (982/1893), and its individual components (severe steatosis, ballooning and lobular inflammation), increased from F0 (33.6%) to F2 (68.6%), and decreased significantly in F4 patients (51.8%) (P = .0001). More than 70% of non-NASH patients showed some inflammatory activity (ballooning or lobular inflammation), showing a similar MAFLD rate than NASH (96.2% [945/982] vs. 95.2% [535/562]) and significantly higher than nonalcoholic fatty liver (NAFL) subjects (89.1% [311/349]) (P < .0001). Progression to cirrhosis was similar between NASH (9.5% [51/539]) and indeterminate NASH (7.9% [25/316]), and higher than steatosis (5% [14/263]) (logRank 8.417; P = .015). Death and decompensated cirrhosis were similar between these.[Conclusions] The prevalence of steatohepatitis decreased in advanced liver disease. However, most of these patients showed some inflammatory activity histologically and had metabolic disturbances. These findings should be considered in clinical trials whose main aim is to prevent cirrhosis progression and complications, liver transplant and death.This project has been partially funded by the ‘Consejería de Salud de la Junta de Andalucía’ (PI-0075-2014) and the ‘Spanish Ministry of Economy, Innovation and Competition, Instituto de Salud Carlos III’ (PI19/01404, PI16/01842, PI17/00535 and GLD19/00100).Peer reviewe

Real-world safety and effectiveness of maintenance niraparib for platinum-sensitive recurrent ovarian cancer: A GEICO retrospective observational study within the Spanish expanded-access programme

[Aim] To describe patient characteristics, effectiveness and safety in a real-world population treated with niraparib in the Spanish expanded-access programme.[Patients and methods] This retrospective observational study included women with platinum-sensitive recurrent high-grade serous ovarian cancer who received maintenance niraparib within the Spanish niraparib expanded-access programme. Eligible patients had received ≥2 previous lines of platinum-containing therapy, remained platinum-sensitive after the penultimate line of platinum and had responded to the most recent platinum-containing therapy. Niraparib dosing was at the treating physician's discretion (300 mg/day fixed starting dose or individualised starting dose [ISD] according to baseline body weight and platelet count). Safety, impact of dose adjustments, patient characteristics and effectiveness were analysed using data extracted from medical records.[Results] Among 316 eligible patients, 80% had BRCA wild-type tumours and 66% received an ISD. Median niraparib duration was 7.8 months. The most common adverse events typically occurred within 3 months of starting niraparib. Median progression-free survival was 8.6 (95% confidence interval [CI] 7.6–10.0) months. One- and 2-year overall survival rates were 86% (95% CI 81–89%) and 65% (95% CI 59–70%), respectively. Dose interruptions, dose reductions, haematological toxicities and asthenia/fatigue were less common with ISD than fixed starting dose niraparib, but progression-free survival was similar irrespective of dosing strategy. Subsequent therapy included platinum in 71% of patients who received further treatment.[Conclusion] Outcomes in this large real-world dataset of niraparib-treated patients are consistent with phase III trials, providing reassuring evidence of the tolerability and activity of niraparib maintenance therapy for platinum-sensitive recurrent ovarian cancer.[ClinicalTrials.gov registration] NCT04546373.Peer reviewe

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Spread of a SARS-CoV-2 variant through Europe in the summer of 2020

[EN] Following its emergence in late 2019, the spread of SARS-CoV-21,2 has been tracked by phylogenetic analysis of viral genome sequences in unprecedented detail3,4,5. Although the virus spread globally in early 2020 before borders closed, intercontinental travel has since been greatly reduced. However, travel within Europe resumed in the summer of 2020. Here we report on a SARS-CoV-2 variant, 20E (EU1), that was identified in Spain in early summer 2020 and subsequently spread across Europe. We find no evidence that this variant has increased transmissibility, but instead demonstrate how rising incidence in Spain, resumption of travel, and lack of effective screening and containment may explain the variant’s success. Despite travel restrictions, we estimate that 20E (EU1) was introduced hundreds of times to European countries by summertime travellers, which is likely to have undermined local efforts to minimize infection with SARS-CoV-2. Our results illustrate how a variant can rapidly become dominant even in the absence of a substantial transmission advantage in favourable epidemiological settings. Genomic surveillance is critical for understanding how travel can affect transmission of SARS-CoV-2, and thus for informing future containment strategies as travel resumes.S

Dispersal history of SARS-CoV-2 in Galicia, Spain

The dynamics of SARS-CoV-2 transmission are influenced by a variety of factors, including social restrictions and the emergence of distinct variants. In this study, we delve into the origins and dissemination of the Alpha, Delta, and Omicron variants of concern in Galicia, northwest Spain. For this, we leveraged genomic data collected by the EPICOVIGAL Consortium and from the GISAID database, along with mobility information from other Spanish regions and foreign countries. Our analysis indicates that initial introductions during the Alpha phase were predominantly from other Spanish regions and France. However, as the pandemic progressed, introductions from Portugal and the USA became increasingly significant. Notably, Galicia’s major coastal cities emerged as critical hubs for viral transmission, highlighting their role in sustaining and spreading the virus. This research emphasizes the critical role of regional connectivity in the spread of SARS-CoV-2 and offers essential insights for enhancing public health strategies and surveillance measures.This work was funded by grant EPICOVIGAL FONDO SUPERA-COVID19 from Banco Santander-CSIC-CRUE and grant CT850A-2 from ACIS SERGAS from the Consellería de Sanidade Xunta de Galicia. PGG was supported by grant ED481A-2021/345 from the Consellería de Cultura, Educación e Universidade Xunta de Galicia. SD acknowledges support from the Fonds National de la Recherche (F.R.S.-FNRS, Belgium; grant no. F.4515.22). SD and GB acknowledge support from the Research Foundation - Flanders (Fonds voor Wetenschappelijk Onderzoek - Vlaanderen, FWO, Belgium; grant no. G098321N) and from the European Union Horizon RIA 2023 project LEAPS (grant no. 101094685). GB acknowledges support from the Internal Funds KU Leuven (Grant No. C14/18/094), from the Research Foundation - Flanders (Fonds voor Wetenschappelijk Onderzoek - Vlaanderen, FWO, Belgium; grant no. G0E1420N) and from the DURABLE EU4Health project 02/2023-01/2027, which is co-funded by the European Union (call EU4H-2021-PJ4; grant no. 101102733). SD and PL acknowledge support from the European Union Horizon 2020 project MOOD (grant agreement no. 874850). PL and MAS acknowledge support from the European Union's Horizon 2020 research and innovation programme (grant agreement no. 725422 - ReservoirDOCS), from the Wellcome Trust through project 206298/Z/17/Z and from the National Institutes of Health grants R01 AI153044, R01 AI162611 and U19 AI135995. PL also acknowledges support from the Research Foundation - Flanders (Fonds voor Wetenschappelijk Onderzoek - Vlaanderen, G0D5117N, and G051322N); MIV, JCS and NSO acknowledge support from the Foundation for Science and Technology (FCT) (project UIDB/50026/2020, UIDP/50026/2020).N

Dispersal history of SARS-CoV-2 in Galicia, Spain

13 páginas, 4 figurasThe dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission are influenced by a variety of factors, including social restrictions and the emergence of distinct variants. In this study, we delve into the origins and dissemination of the Alpha, Delta, and Omicron-BA.1 variants of concern in Galicia, northwest Spain. For this, we leveraged genomic data collected by the EPICOVIGAL Consortium and from the GISAID database, along with mobility information from other Spanish regions and foreign countries. Our analysis indicates that initial introductions during the Alpha phase were predominantly from other Spanish regions and France. However, as the pandemic progressed, introductions from Portugal and the United States became increasingly significant. The number of detected introductions varied from 96 and 101 for Alpha and Delta to 39 for Omicron-BA.1. Most of these introductions left a low number of descendants (<10), suggesting a limited impact on the evolution of the pandemic in Galicia. Notably, Galicia's major coastal cities emerged as critical hubs for viral transmission, highlighting their role in sustaining and spreading the virus. This research emphasizes the critical role of regional connectivity in the spread of SARS-CoV-2 and offers essential insights for enhancing public health strategies and surveillance measures.This work was funded by grant EPICOVIGAL FONDO SUPERA-COVID19 from Banco Santander-CSIC-CRUE and grant CT850A-2 from ACIS SERGAS from the Consellería de Sanidade Xunta de Galicia. PGG was supported by grant ED481A-2021/345 from the Consellería de Cultura, Educación e Universidade Xunta de Galicia. SD acknowledges support from the Fonds National de la Recherche (F.R.S.-FNRS, Belgium; grant no. F.4515.22). SD and GB acknowledge support from the Research Foundation - Flanders (Fonds voor Wetenschappelijk Onderzoek - Vlaanderen, FWO, Belgium; grant no. G098321N) and from the European Union Horizon RIA 2023 project LEAPS (grant no. 101094685). GB acknowledges support from the Internal Funds KU Leuven (Grant No. C14/18/094), from the Research Foundation - Flanders (Fonds voor Wetenschappelijk Onderzoek - Vlaanderen, FWO, Belgium; grant no. G0E1420N) and from the DURABLE EU4Health project 02/2023-01/2027, which is co-funded by the European Union (call EU4H-2021-PJ4; grant no. 101102733). SD and PL acknowledge support from the European Union Horizon 2020 project MOOD (grant agreement no. 874850). PL and MAS acknowledge support from the European Union's Horizon 2020 research and innovation programme (grant agreement no. 725422 - ReservoirDOCS), from the Wellcome Trust through project 206298/Z/17/Z and from the National Institutes of Health grants R01 AI153044, R01 AI162611 and U19 AI135995. PL also acknowledges support from the Research Foundation - Flanders (Fonds voor Wetenschappelijk Onderzoek - Vlaanderen, G0D5117N, and G051322N); MIV, JCS and NSO acknowledge support from the Foundation for Science and Technology (FCT) (project UIDB/50026/2020, UIDP/50026/2020).Peer reviewe