Mecanismos compensatorios a nivel sistémico en pacientes con tronco arterial persistente / Systemic Compensatory Mechanisms in Patients with Persistent Truncus Arteriosus

Resumen Introducción: El tronco arterial persistente es una rara malformación cardíaca congénita que provoca diversas complicaciones en el sistema cardiovascular. Se caracteriza por la presencia de un tabique ventricular defectuoso, una única válvula troncal y un tronco arterial común entre la arteria pulmonar y aorta, conllevando a una mezcla entre la sangre arterial y venosa, debido a un cortocircuito cardíaco bidireccional predominante de izquierda a derecha que compromete el suministro de flujo sanguíneo, nutrientes y oxigenación sistémica. Las manifestaciones clínicas incluyen desaturación con cianosis, hipoxemia, taquicardia, taquipnea, alteraciones en la contractilidad cardíaca, pulsos distales anómalos, pérdida de peso, fatiga y hepatomegalia. Objetivo: El propósito de esta investigación es establecer hipótesis sobre los diversos mecanismos compensatorios que se activan a nivel sistémico para contrarrestar los efectos de esta malformación. Reflexión: Se sugiere que se producen respuestas biomoleculares similares en los sistemas cardiovascular, pulmonar y renal, reduciendo la producción de óxido nítrico y provocando respuestas vasoconstrictoras. A nivel hepático, se generan factores de crecimiento y se inician procesos de angiogénesis para aumentar la perfusión sanguínea. En el cerebro, se activan enzimas para incrementar el flujo sanguíneo y proporcionar oxígeno y nutrientes esenciales. Conclusión: A pesar de estos mecanismos compensatorios, no logran contrarrestar por completo las manifestaciones clínicas, conduciendo a una serie de problemas de salud, como hipertensión pulmonar, insuficiencia cardíaca, hepatomegalia, hipoperfusión de órganos y déficits neurológicos. Estos factores convergen para generar una compleja condición cardíaca que desencadena respuestas adaptativas en el cuerpo que terminan siendo una afección médica desafiante y potencialmente grave.

Abstract Introduction: Persistent truncus arteriosus is a rare congenital cardiac malformation that causes various complications in the cardiovascular system. It is characterized by the presence of a defective ventricular septum, a single truncal valve and a common truncus arteriosus between the pulmonary artery and aorta, leading to a mixture between arterial and venous blood, due to a predominantly left-to-right bidirectional cardiac shunt that compromises the supply of blood flow, nutrients, and systemic oxygenation. Clinical manifestations include desaturation with cyanosis, hypoxemia, tachycardia, tachypnea, alterations in cardiac contractility, abnormal distal pulses, weight loss, fatigue, and hepatomegaly. Aim: The purpose of this research is to establish hypotheses about the various compensatory mechanisms that are activated at a systemic level to counteract the effects of this malformation. Reflection: It is suggested that similar biomolecular responses occur in the cardiovascular, pulmonary, and renal systems, reducing nitric oxide production and causing vasoconstrictive responses. At the liver level, growth factors are generated and angiogenesis processes are initiated to increase blood perfusion. In the brain, enzymes are activated to increase blood flow and provide oxygen and essential nutrients. Conclusion: Despite these compensatory mechanisms, they fail to completely counteract the clinical manifestations, leading to a series of health problems such as pulmonary hypertension, heart failure, hepatomegaly, organ hypoperfusion, and neurological deficits. These factors converge to generate a complex cardiac condition that triggers adaptive responses in the body that end up being a challenging and potentially serious medical condition.

[Epigenetic changes in alcohol addiction and therapeutic perspectives]. / Modifications épigénétiques dans l'addiction à l'alcool et perspectives thérapeutiques.

Alcohol consumption is a major public health issue. Patients with Alcohol Use Disorder (AUD) can benefit from five treatments that preferentially target membrane receptors, and whose efficacy is generally modest. However, a large body of experimental evidence points to an important role for epigenetics in the effects of alcohol consumption, and epidrugs that modify the epigenome offer an interesting alternative to current therapeutic options. This article reviews the most striking experimental evidence obtained at different ages in animal models, before comparing it with data obtained in humans and concluding on the relevance of using epidrugs. Finally, a new therapeutic option is suggested between psychedelics, recent molecules of interest, and epigenetic factors in alcohol intake.

Comportamiento alimentario de Aedes aegypti en brotes de dengue de dos zonas rurales del Perú durante el ciclón Yaku y El Niño Global del 2023 / Aedes aegypti feeding behavior during dengue outbreaks in two rural areas of Peru during the Yaku cyclone and El Niño phenomenon of 2023

RESUMEN Objetivos. Determinar la alimentación del Aedes aegypti en brotes de dengue de dos zonas rurales del Perú durante el ciclón Yaku y El Niño Global del 2023. Material y métodos. Se analizaron ocho muestras de sangre (8 pooles) obtenidas del abdomen de 80 especímenes Aedes aegypti capturados en los distritos rurales de Querecotillo y Marcavelica durante brotes de dengue acontecidos en el ciclón Yaku y en El Niño Global. Se extrajo ADN de las muestras analizadas, se llevó a cabo una PCR dirigida al gen CytB como marcador genético y los productos PCR fueron digeridos enzimáticamente con las restrictasas Hae III y Mwo I. Los productos PCR-RFLP fueron visualizados por electroforesis en gel de agarosa al 4%. Resultados. Se obtuvo ADN de todas las muestras y como producto PCR un amplicón de 358 pb. Así mismo, el único RFLP en Hae III observado fue el de Homo sapiens sapiens (233 y 125 pb). No se observó RFLP en Hae III de Gallus gallus y RFLP en Mwo I de Canis familiaris y Mus musculus. Conclusión. En brotes de dengue de zonas rurales, durante el ciclón Yaku y en El Niño Global, el Aedes aegypti presentó un comportamiento alimenticio antropofílico conservado.

ABSTRACT Objective. To determine the feeding behavior of Aedes aegypti in dengue outbreaks in two rural areas of Peru during the Yaku cyclone and El Niño phenomenon of 2023. Material and methods. Eight blood samples (8 pools) were obtained from the abdomen of 80 Aedes aegypti specimens captured in the rural districts of Querecotillo and Marcavelica during the Yaku cyclone and El Niño dengue outbreaks. DNA was extracted from the analyzed samples, then a PCR was directed at the CytB gene as a genetic marker and the PCR products were enzymatically digested with the restrictases Hae III and Mwo I. The PCR-RFLP products were visualized by agarose gel electrophoresis at 4%. Results. DNA was obtained from all samples and a 358 bp amplicon was obtained as a PCR product. Likewise, the only RFLP found in Hae III was from Homo sapiens sapiens (233 and 125 bp). RFLP was not found in Hae III of Gallus gallus and RFLP in Mwo I of Canis familiaris and Mus musculus. Conclusion. Aedes aegypti showed conserved anthropophilic feeding behavior in dengue outbreaks in rural areas during the Yaku cyclone and El Niño.

Impact of kV-cone beam computed tomography dose on DNA repair mechanisms: A pilot study.

PURPOSE: In head and neck squamous cell carcinoma (HNSCC), early complications of the radiotherapy (RT) are observed from the beginning of the treatment to a few months after its end. During external radiotherapy treatment, several patient-dependent parameters can cause a modification of the dose distribution compared to the planned distribution due to variation in patient positioning, anatomy, or intra-fractional movements for example. To verify these parameters during treatment sessions, one of the most commonly used solutions is the cone-beam computed tomography (CBCT). Nowadays, the use of CBCT may constitutes a significant part of the total dose at the end of treatment (up to 10 cGy per session) and more often the volume irradiated by imaging is larger than the one irradiated by the treatment, leading to unintentional irradiation of nearby organs. In this study, we asked whether the imaging low dose added to a following fraction dose (2Gy) may affect the biological response in terms of DNA repair. MATERIAL AND METHODS: Using an IVInomad dosimeter and scintillating fiber probes specially designed for this exploratory study, we exposed fibroblasts cells from head and neck cancer (HNC) patients to a CBCT dose followed by a radiotherapy fraction dose. DNA double strand breaks and DNA repair were assessed by immunofluorescence using the biomarkers gamma H2AX (γH2AX) and pATM. RESULTS: The median dose of CBCT was measured between 17 to 21 mGy per session. The kinetics of both biomarkers were found to be strongly dependent on the individual factor in radiosensitive patients. For HNC patients, a prior CBCT dose applied few minutes before the 2Gy dose may have a sublinear effect on the DNA repair mechanisms and potentially on observed health tissue toxicity. CONCLUSION: The preliminary results obtained highlight the importance of individual and tissue factors for recognizing and repairing DSB during a treatment by radiotherapy using CBCT.

Prediction of radiotherapy toxicity: 20 years of COPERNIC radiosensitivity diagnosis procedure.

PURPOSE: Since 2004, in the frame of the care pathway, our Research Unit has replied to the demand of expertise of radiation oncologists about the individual radiosensitivity of some of their patients. This procedure, called COPERNIC, is based on a skin biopsy and the radiation-induced nucleoshuttling of the ATM protein (the RIANS model), a major actor of DNA break repair and signaling. In 2016, with the first 117COPERNIC fibroblast lines, we obtained a significant correlation between the maximum number of the nuclear ATM foci, pATMmax, and the CTCAE severity grade of the post-radiotherapy tissue reactions. In this study, we propose to verify the validity of our previous findings with a new COPERNIC data subset obtained in the 2014-2024 period. MATERIALS AND METHODS: We applied a standard immunofluorescence technique to quiescent COPERNIC fibroblasts to assess, after 2Gy, the level of micronuclei, γH2AX and pATM foci. The 117 COPERNIC data published in 2016 were considered as the reference data subset. A new COPERNIC data subset composed of 133fibroblast cell lines was considered as the validating data subset. RESULTS: Our data showed that spontaneous or residual micronuclei levels, and residual γH2AX foci levels cannot predict CTCAE grades. Conversely, the linear formula linking the maximal number of pATM foci and the corresponding CTCAE grade and obtained in 2016 from the reference data subset fitted well the validating data. CONCLUSIONS: The maximal number of pATM foci appears to be one of the most reliable biomarkers for predicting post-radiotherapy radiotoxicity.

Theoretical study on multi-perspective interaction analysis of ADN and ADN-H2O-CH3OH solutions.

CONTEXT: Revealing the mechanism of intermolecular interactions in dinitroamine ammonium (ADN)-based liquid propellants and exploring the reasons for their performance changes, multi-perspective interaction analyses of ADN and ADN-water (H2O)-methanol (CH3OH) solutions have been conducted via theoretical methods. The band structure, density of states (DOS), surface electrostatic potential (ESP), Hirshfeld surface, reduced density gradient (RDG), AIM topological analysis, and detonation performance were studied and the results showed that both the ADN and ADN-H2O-CH3OH solutions had hydrogen bonds and van der Waals interactions. By introducing the small molecules H2O and CH3OH, the detonation performance of the ADN-H2O-CH3OH solution slightly decreased, but its sensitivity also decreased. Overall, the comprehensive performance of the ADN-H2O-CH3OH solution has improved, and the application range has expanded. These results are helpful for obtaining a deeper understanding of ADN-based liquid propellants at the atomic level and contribute to the development of new liquid propellants. METHODS: The ADN and ADN-H2O-CH3OH solutions were constructed by Amorphous cell module and optimized via GGA with PBE methods in the Dmol3 module of the Materials Studio, and their electronic properties were calculated. Hirshfeld surfaces were generated with CrystalExplorer 3.0. A topological analysis of a variety of molecular clusters was performed via QTAIM. The QTAIM and RDG analyses in this work were generated by Multiwfn 3.0.

[Metastatic castration-resistant prostate cancer and PARP inhibitors: From tumor genomics to new therapeutic combinations]. / Cancer de prostate métastatique résistant à la castration et inhibiteurs de PARP : de la génomique tumorale aux nouvelles associations thérapeutiques.

Castration-resistant metastatic prostate cancer remains lethal and a therapeutic challenge. Current strategies are geared towards the personalization of treatments based on the identification of relevant molecular targets, including genomic alterations involved in tumoral processes. Among these novel targeted therapies, poly-ADP-ribose polymerase inhibitors (PARPi), by blocking the action of enzymes involved in deoxyribonucleic acid (DNA) repair, induce the destruction of cells carrying defects in homologous recombination repair, often associated with alterations in genes involved in this mechanism. Thus, determining the presence of a molecular anomaly, particularly alterations in the BRCA1/2 genes, is a prerequisite for initiating PARPi monotherapy. In patients with metastatic castration-resistant prostate cancer , around 20-30 % carry this type of mutation. In this population, single-agent studies have demonstrated PARPi ability to prolong overall survival, and to improve symptom control, including pain. Other studies are underway to assess their effectiveness in combination with other therapies, and it already appears that association with new-generation hormone therapy can further prolong radiological progression-free survival, regardless of the mutation status of the genes involved in DNA repair, indicating a synergistic action between PARPi and new-generation hormone therapy.

Three-dimensional conservation planning of fish biodiversity metrics to achieve the deep-sea 30×30 conservation target.

Accelerating rate of human impact and environmental change severely affects marine biodiversity and increases the urgency to implement the Convention on Biological Diversity (CBD) 30×30 plan for conserving 30% of sea areas by 2030. However, area-based conservation targets are complex to identify in a 3-dimensional (3D) ocean where deep-sea features such as seamounts have been seldom studied mostly due to challenging methodologies to implement at great depths. Yet, the use of emerging technologies, such as environmental DNA combined with modern modeling frameworks, could help address the problem. We collected environmental DNA, echosounder acoustic, and video data at 15 seamounts and deep island slopes across the Coral Sea. We modeled 7 fish community metrics and the abundances of 45 individual species and molecular operational taxonomic units (MOTUs) in benthic and pelagic waters (down to 600-m deep) with boosted regression trees and generalized joint attribute models to describe biodiversity on seamounts and deep slopes and identify 3D protection solutions for achieving the CBD area target in New Caledonia (1.4 million km2). We prioritized the identified conservation units in a 3D space, based on various biodiversity targets, to meet the goal of protecting at least 30% of the spatial domain, with a focus on areas with high biodiversity. The relationship between biodiversity protection targets and the spatial area protected by the solution was linear. The scenario protecting 30% of each biodiversity metric preserved almost 30% of the considered spatial domain and accounted for the 3D distribution of biodiversity. Our study paves the way for the use of combined data collection methodologies to improve biodiversity estimates in 3D structured marine environments for the selection of conservation areas and for the use of biodiversity targets to achieve area-based international targets.

Planeación tridimensional de la conservación de las medidas de biodiversidad de peces para lograr el objetivo de conservación 30x30 de mar profundo Resumen El impacto antropogénico y el cambio ambiental acelerados afectan gravemente a la biodiversidad marina y aumentan la urgencia de aplicar el plan 30x30 del Convenio sobre la Diversidad Biológica (CDB) para conservar el 30% de las zonas marinas para el 2030. Sin embargo, la identificación de objetivos de conservación basados en zonas es compleja en un océano tridimensional (3D) en el que rara vez se han estudiado las características de las profundidades marinas, como los montes marinos, sobre todo por la dificultad de aplicar metodologías a grandes profundidades. No obstante, el uso de tecnologías emergentes, como el ADN ambiental combinado con marcos actuales de modelación, podría ayudar a resolver el problema. Recopilamos datos de ADN ambiental, acústica de ecosonda y video en 15 montes marinos y taludes de islas profundas del mar del Coral. Modelamos siete medidas de comunidades de peces y 45 abundancias de especies individuales y unidades taxonómicas moleculares (UTOM) en aguas bentónicas y pelágicas (hasta 600 m de profundidad) con árboles de regresión reforzada (ARR) y modelos de atributos conjuntos generalizados (MACJ) para describir la biodiversidad en los montes marinos y taludes profundos e identificar soluciones de protección en 3D para alcanzar el objetivo de área del CDB en Nueva Caledonia (1.4 millones de km2). Priorizamos las unidades de conservación identificadas en un espacio 3D con base en varios objetivos de biodiversidad para cumplir el objetivo de proteger al menos el 30% del dominio espacial con un enfoque en las zonas con una gran biodiversidad. La relación entre los objetivos de protección de la biodiversidad y el área espacial protegida por la solución fue lineal. El escenario que protegía el 30% de cada medida de biodiversidad preservó casi el 30% del dominio espacial considerado y consideró la distribución tridimensional de la biodiversidad. Nuestro estudio prepara el camino para el uso de metodologías combinadas de recopilación de datos con el fin de mejorar las estimaciones de biodiversidad en entornos marinos estructurados en 3D para la selección de áreas de conservación y para el uso de objetivos de biodiversidad con el fin de alcanzar objetivos internacionales basados en áreas.

Childhood trauma is linked to epigenetic age deceleration in young adults with previous youth residential care placements.

Background: Early adversity increases the risk for mental and physical disorders as well as premature death. Epigenetic processes, and altered epigenetic aging in particular, might mediate these effects. While the literature that examined links between early adversity and epigenetic aging is growing, results have been heterogeneous.Objective: In the current work, we explored the link between early adversity and epigenetic aging in a sample of formerly out-of-home placed young adults.Method: A total of N = 117 young adults (32% women, age mean = 26.3 years, SD = 3.6 years) with previous youth residential care placements completed the Childhood Trauma Questionnaire (CTQ) and the Life Events Checklist (LEC-R) and provided blood samples for the analysis of DNA methylation using the Illumina Infinium MethylationEPIC BeadChip Microarray. Epigenetic age was estimated using Hovarth's and Hannum's epigenetic clocks. Furthermore, Hovarth's and Hannum's epigenetic age residuals were calculated as a proxy of epigenetic aging by regressing epigenetic age on chronological age. The statistical analysis plan was preregistered (https://osf.io/b9ev8).Results: Childhood trauma (CTQ) was negatively associated with Hannum's epigenetic age residuals, ß = -.23, p = .004 when controlling for sex, BMI, smoking status and proportional white blood cell type estimates. This association was driven by experiences of physical neglect, ß = -.25, p = .001. Lifetime trauma exposure (LEC-R) was not a significant predictor of epigenetic age residuals.Conclusion: Childhood trauma, and physical neglect in particular, was associated with decelerated epigenetic aging in our sample. More studies focusing on formerly institutionalized at-risk populations are needed to better understand which factors affect stress-related adaptations following traumatic experiences.

Growing literature links early adversity to altered epigenetic aging, yet results have been heterogeneous.We assessed childhood and lifetime trauma exposure using the Childhood Trauma Questionnaire and the Life Events Checklist and estimated epigenetic aging by obtaining Horvath's and Hannum's epigenetic age residuals in a sample of formerly out-of-home placed young adults.In this high-risk sample, childhood trauma, physical neglect in particular, but not lifetime trauma was negatively related to epigenetic aging.

Kinetics of plasma cell-free DNA as a prospective biomarker to predict the prognosis and radiotherapy effect of esophageal cancer.

PURPOSE: The lack of reliable biomarkers for the prognosis and radiotherapy efficacy in esophageal cancer (EC) necessitates further research. The aim of our study was to investigate the predictive utility of plasma cell-free DNA (cfDNA) kinetics in patients with EC. MATERIALS AND METHODS: We retrospectively analyzed the clinical data and cfDNA levels (pre-radiotherapy [pre-RT] and post-radiotherapy [post-RT]) and the cfDNA kinetics (cfDNA ratio: post-RT cfDNA/pre-RT cfDNA) of 88 patients. We employed Kaplan-Meier curves to examine the relationship between cfDNA and overall survival (OS) as well as progression-free survival (PFS). Univariate and multivariate Cox regression analyses were executed to ascertain the independent risk factors in EC. RESULTS: The pre-RT cfDNA levels were positively correlated with clinical stage (P=0.001). The pre-RT cfDNA levels (cutoff value=16.915ng/mL), but not the post-RT cfDNA levels, were linked to a diminished OS (P<0.001) and PFS (P=0.0137). CfDNA kinetics (cutoff value=0.883) were positively associated with OS (P=0.0326) and PFS (P=0.0020). Notably, we identified independent risk factors for OS in EC treated with RT, including cfDNA ratio (high/low) (HR=0.447 [0.221-0.914] P=0.025), ECOG (0/1/2) (HR=0.501 [0.285-0.880] p=0.016), and histological type (esophagal squamous cell carcinoma [ESCC]/non-ESCC) (HR=3.973 [1.074-14.692] P=0.039). CONCLUSION: Plasma cfDNA kinetics is associated with prognosis and radiotherapy effect in EC undergoing RT, suggesting potential clinical application of a cheap and simple blood-based test.

Comparison of Hybribio-H13 and Hybrid Capture® 2 human papillomavirus tests for detection of CIN2+ and CIN3+ / Comparación de las pruebas para el virus del papiloma humano Hybribio-H13 y Hybrid Capture® 2 para la detección de NIC2+ y NIC3+

Introduction. Low-cost, accurate high-risk HPV tests are needed for cervical cancer screening in limited-resource settings. Objective. To compare the performance of the low-cost Hybribio-H13 test with the Hybrid Capture® 2 to detect cervical intraepithelial neoplasia grade 2 or 3 (CIN2 and CIN3). Materials and methods. Archived baseline samples tested by the Hybrid Capture® 2 from women of the ASCUS-COL trial, aged 20 to 69 years, with biopsy-colposcopy directed diagnosis of CIN2+ (n = 143), CIN3+ (n = 51), and < CIN2 (n = 632) were blindly tested by the Hybribio-H13 test. Results. Therelative sensitivity of the Hybribio-H13 test versus the Hybrid Capture® 2 for detecting CIN2+ was 0.89 (90% CI = 0,80-0,98; NIT = 0,66), and for CIN3+ was 0,92 (90% CI = 0,85-0,98; NIT = 0,35). Relative specificity was 1.19 (90% CI = 1.05-1.33; NIT < 0.00001). In the analysis restricted to women older than 30 years, the relative sensitivity of the Hybribio-H13 for CIN3+ was marginally below unity (ratio = 0.97; 90% CI = 0.95-0.99), and the specificity remained higher than the Hybrid Capture® 2 test. Conclusion. The Hybribio-H13 test was as specific as the Hybrid Capture® 2 for detecting CIN2+ or CIN3+ but less sensitive. Considering these results and the young age of the population recruited for screening because of ASCUS cytology, we suggest our results warrant the evaluation of the Hybribio-H13 for screening cervical cancer, especially in the evaluated population.

Introducción. Se necesitan pruebas para detectar genotipos de VPH de alto riesgo, precisas y de bajo costo, para la tamización del cáncer de cuello uterino en entornos de recursos limitados. Objetivo. Comparar el desempeño de la prueba de bajo costo Hybrid-H13 con la de Hybrid Capture® 2para detectar NIC2+ y NIC3+. Materiales y métodos. Se analizaron en ciego muestras de la línea base provenientes de mujeres del estudio ASCUS-COL, entre los 20 y los 69 años, con diagnóstico dirigido por biopsia-colposcopia de NIC2+ (n = 143), NIC3 + (n = 51) y < NIC2 (n = 632) con la prueba para detección de virus de papiloma humano Hybribio-H13. Estas muestras fueron previamente evaluadas con la prueba Hybrid Capture® 2. Resultados. La sensibilidad relativa de Hybribio-13 versus la de Hybrid Capture® 2 para detectar NIC2+ fue de 0,89 (IC90%: 0,80-0,98; NIT = 0,66) y para NIC3+ fue de 0,92 (IC90%: 0,85-0,98; NIT = 0,35). La especificidad relativa fue de 1,19 (IC90%: 1,05-1,33; NIT < 0,00001). En el análisis restringido a mujeres mayores de 30 años, la sensibilidad relativa de Hybribio-H13 para NIC3+ estuvo marginalmente por debajo de la unidad (proporción = 0,97; IC90%: 0,95-0,99) y la especificidad permaneció más alta que la de la prueba Hybrid Capture® 2. Conclusión. La prueba de Hybribio-H13 fue tan específica como la de Hybrid Capture® 2, pero menos sensible para detectar NIC2+ o NIC3+. Teniendo en cuenta estos resultados y la temprana edad de la población reclutada en la tamización por la presencia de ASCUS en la citología, se sugiere continuar con la evaluación de la prueba Hybribio-H13 para la detección de cáncer de cuello uterino en poblaciones con las mismas características que las de la aquí evaluada.

Perfil molecular de cáncer de endometrio en mujeres de Bogotá DC, Colombia / Molecular profile of endometrial cancer in women from Bogota DC, Colombia

Introducción: El cáncer de endometrio ocupa el sexto lugar en incidencia del cáncer en mujeres. La caracterización molecular de este cáncer permite optimizar la estratificación de riesgo para mejorar el tratamiento de las pacientes. Objetivo: Determinar el perfil molecular TCGA de pacientes con cáncer de endometrio en Bogotá, D.C., Colombia. Método: Estudio descriptivo en una cohorte de pacientes con cáncer de endometrio. Las mutaciones en los exones 9 a 14 del gen POLE fueron identificadas mediante amplificación por reacción en cadena de la polimerasa, seguida de secuenciación Sanger y análisis bioinformático. La expresión de las proteínas MMR y p53 se identificó mediante inmunohistoquímica. Resultados: Se incluyeron 40 pacientes con una mediana de edad de 66 años. El 15% presentaron mutaciones en el dominio exonucleasa de POLE. El 32% de las pacientes que no presentaron mutaciones manifestaron deficiencia en el sistema MMR. El 43,47% de las pacientes sin mutaciones en POLE ni alteración del sistema MMR presentaron alteración de la proteína p53. Conclusiones: La población de cáncer de endometrio analizada presenta un perfil molecular TCGA similar a lo reportado para otras poblaciones.

Introduction: Endometrial cancer ranks sixth in cancer incidence among women. Its molecular characterization allows for a more precise risk stratification with the aim of improving patient treatment. Objective: To determine the TCGA molecular profile of patients with endometrial cancer in Bogota, Colombia. Method: A descriptive study of a cohort of patients with endometrial cancer. The expression of MMR proteins and p53 was identified through immunohistochemistry. Mutations in exons 9 to 14 of the POLE gene were identified through polymerase chain reaction amplification, followed by Sanger sequencing and bioinformatic analysis. Results: Forty patients were included in the study, with a median age of 66 years, 15% of them exhibited mutations in the exonuclease domain of POLE, while 32% of patients without mutations showed deficiency in the MMR system. Forty three percent of patients without mutations in POLE or MMR alterations showed aberrant p53 protein expression. Conclusions: The analyzed population of endometrial cancer presents a TCGA molecular profile similar to that reported for other populations.

Evaluation of imidacloprid (Confidor OD®) genotoxicity in Chrysoperla externa eggs (Neuroptera: Chrysopidae) through comet assay.

The comet assay allows the analysis of DNA damage caused by different genotoxins. This assay has recently gained interest because of its ease of studying the interactions of xenobiotics with different organisms. Chrysoperla externa (Hagen, 1861) is a species of great economic relevance because it is a predator of major agricultural pests during its larval stage. Neonicotinoids are the most important chemical class of insecticides introduced into markets. A previous imidacloprid toxicity assessment on C. externa showed that this neonicotinoid insecticide reduced the egg viability. The objective of this study was to analyze the genotoxicity of Confidor OD® (imidacloprid 20% a.i., LS, Bayer CropScience) on the biological control agent C. externa at DNA level using the comet assay as an ecotoxicological biomarker. A comet assay protocol has been developed for this species at first time. For the bioassays, the commercial product formulated Confidor OD® was used at two concentrations: 100 and 180 mg/l of the active ingredient. Selected eggs were dipped in a Confidor OD® solution for 15 s. Descriptors evaluated in the comet assay were damage index, % DNA damage, and tail length. The damage index did not show any significant differences between the different concentrations evaluated, but differences were observed for tail length, because at higher concentrations of Confidor OD®, there were greater DNA breaks. The DNA of the cells from treated eggs analyzed at 48 h and 96 h of development showed the same % DNA damage; that is, they had no recovery capacity. Application of Confidor OD® to C. externa eggs produced irreparable breaks at the DNA level. The technique adjusted for C. externa can be used in other beneficial insects to study pesticide genotoxicity using a comet assay.

Importancia biológica de los telómeros / Biological importance of telomeres

Se exponen los hallazgos históricos y la importancia biológica de los telómeros en la vida celular y en los aspectos genéticos del ADN humano. (AU)

The discovery and the biological importance of the telomeres are exposed. (AU)

Recent molecular techniques to strengthen ecological studies in echinoderms / Técnicas moleculares recientes que fortalecen los estudios ecológicos de equinodermos

Abstract Introduction: Echinoderms, an integral component of marine ecosystems worldwide, have captivated scientific interest for centuries. Despite this longstanding attention, comprehending key facets such as trophic relationships, diet composition, and host-microbiota relationships still represents a challenge using traditional techniques. Recent years, however, have witnessed a transformative shift, thanks to the emergence of advanced molecular techniques, offering new approaches to strengthen ecological studies in echinoderms. Objective: Explore how recent advancements in molecular tools have impacted ecological research on echinoderms. Specifically, we aim to investigate the potential of these tools to shed light on trophic interactions, diet composition, and the characterization of gut microbial communities in these organisms. Methods: Available literature was used to clarify how novel molecular techniques can improve ecological studies. The focus is diet, trophic relationships, and gut microbiota. Results: Traditionally, studies of stomach contents using compound microscopy have provided an idea of ingested material; nevertheless, sometimes a simple magnified visualization of dietary content does not allow exhaustive identification of the entire food spectrum, as it is limited due to the rapid digestion and maceration of food items within the echinoderm's digestive tract. The use of DNA-metabarcoding, targeting specific DNA regions, such as the mitochondrial COI gene, has allowed us to enhance the accuracy and precision of diet characterization by enabling the identification of prey items down to the species or even genetic variant level, providing valuable insights into specific dietary preferences. Another approach is the use of stable isotopes, particularly carbon and nitrogen, which provide a powerful tool to trace the origin and flow of nutrients through food webs. By analyzing the isotopic signatures in muscular tissues and food items, we can discern the sources of their primary food items and gain insights into their trophic position within the ecosystem. Lastly, a third new technique used to elucidate the characterization of the prokaryotic community is 16S rRNA sequencing. This method allows us to explore the composition and dynamics of the digestive tract microbial communities. Conclusions: This is a promising era for ecological research on echinoderms, where advances of molecular tools have enabled an unprecedented level of detail, resolving longstanding challenges in comprehending their trophic interactions, diet composition, and host-microbiota relationships, and opening new avenues of investigation in ecological studies.

Resumen Introducción: Los equinodermos, un componente integral de los ecosistemas marinos en todo el mundo, han captado el interés científico durante siglos. A pesar de esta prolongada atención, el comprender facetas clave como las relaciones tróficas, la composición de la dieta y las relaciones huésped-microbiota todavía representa un desafío utilizando técnicas tradicionales. Sin embargo, los últimos años han sido testigos de un cambio transformador, gracias a la aparición de técnicas moleculares avanzadas, que ofrecen nuevos enfoques para fortalecer los estudios ecológicos en equinodermos. Objetivo: Explorar cómo los avances recientes en herramientas moleculares han impactado la investigación ecológica sobre equinodermos. Específicamente, nuestro objetivo es investigar el potencial de estas herramientas para arrojar luz sobre las interacciones tróficas, la composición de la dieta y la caracterización de las comunidades microbianas intestinales en estos organismos. Métodos: Se utilizó la literatura disponible para aclarar cómo las nuevas técnicas moleculares pueden mejorar los estudios ecológicos. La atención se centra en la dieta, las relaciones tróficas y la microbiota intestinal. Resultados: Tradicionalmente, los estudios del contenido estomacal mediante microscopía compuesta han proporcionado una idea del material ingerido; Sin embargo, a veces una simple visualización ampliada del contenido dietético no permite una identificación exhaustiva de todo el espectro alimentario, ya que está limitado debido a la rápida digestión y maceración de los alimentos dentro del tracto digestivo del equinodermo. El uso de metabarcoding de ADN, dirigidos a regiones específicas del ADN, como el gen COI mitocondrial, nos ha permitido mejorar la exactitud y precisión de la caracterización de la dieta al permitir la identificación de presas hasta el nivel de especie o incluso de variante genética, lo que proporciona valiosos resultados sobre preferencias dietéticas específicas. Otro enfoque es el uso de isótopos estables, en particular carbono y nitrógeno, que proporcionan una poderosa herramienta para rastrear el origen y el flujo de nutrientes a través de las redes alimentarias. Al analizar las firmas isotópicas en los tejidos musculares y los alimentos, podemos discernir las fuentes de sus alimentos primarios y obtener información sobre su posición trófica dentro del ecosistema. Por último, una tercera técnica nueva utilizada para dilucidar la caracterización de la comunidad procariótica es la secuenciación del ARNr 16S. Este método nos permite explorar la composición y dinámica de las comunidades microbianas del tracto digestivo. Conclusiones: Esta es una era prometedora para la investigación ecológica sobre equinodermos, donde los avances de las herramientas moleculares han permitido un nivel de detalle sin precedentes, resolviendo desafíos de larga data en la comprensión de sus interacciones tróficas, composición de la dieta y relaciones huésped-microbiota, y abriendo nuevas vías de investigación. en estudios ecológicos.

Evaluating the reliability of DNA Barcoding for Central American Pacific shallow water echinoderms identification: a molecular taxonomy and database accuracy analysis / Evaluando la fiabilidad del Código de Barras de ADN para la identificación de equinodermos en aguas poco profundas del Pacífico de América Central: un análisis de taxonomía molecular y precisión de bases de datos

Abstract Introduction: Molecular divergence thresholds have been proposed to distinguish recently separated evolutive units, often displaying more accurate putative species assignments in taxonomic research compared to traditional morphological approaches. This makes DNA barcoding an attractive identification tool for a variety of marine invertebrates, especially for cryptic species complexes. Although GenBank and the Barcode of Life Data System (BOLD) are the major sequence repositories worldwide, very few have tested their performance in the identification of echinoderm sequences. Objective: We use COI echinoderm sequences from local samples and the molecular identification platforms from GenBank and BOLD, in order to test their accuracy and reliability in the DNA barcoding identification for Central American shallow water echinoderms, at genus and species level. Methods: We conducted sampling, tissue extraction, COI amplification, sequencing, and taxonomic identification for 475 specimens. The 348 obtained sequences were individually enquired with BLAST in GenBank as well as using the Identification System (IDS) in BOLD. Query sequences were classified depending on the best match result. McNemar's chi-squared, Kruskal-Wallis's and Mann-Whitney's U tests were performed to prove differences between the results from both databases. Additionally, we recorded an updated list of species reported for the shallow waters of the Central American Pacific. Results: We found 324 echinoderm species reported for Central American Pacific shallow waters. Only 118 and 110 were present in GenBank and BOLD databases respectively. We proposed 325 solved morphology-based identities and 21 provisional identifications in 50 putative taxa. GenBank retrieved 348 molecular-based identifications in 58 species, including twelve provisional identifications in tree taxa. BOLD recovered 170 COI identifications in 23 species with one provisional identification. Nevertheless, 178 sequences retrieved unmatched terms (in 34 morphology-based taxa). Only 86 sequences (25 %) were retrieved as correct identifications and 128 (37 %) as identification errors in both platforms. We include 84 sequences for eleven species not represented in GenBank and 65 sequences for ten species in BOLD Echinoderm COI databases. The identification accuracy using BLAST (175 correct and 152 incorrect identifications) was greater than with IDS engine (110 correct and 218 identification errors), therefore GenBank outperforms BOLD (Kruskal-Wallis = 41.625, df = 1, p < 0.001). Conclusions: Additional echinoderm sample references are needed to improve the utility of the evaluated DNA barcoding identification tools. Identification discordances in both databases may obey specific parameters used in each search algorithm engine and the available sequences. We recommend the use of barcoding as a complementary identification source for Central American Pacific shallow water echinoderm species.

Resumen Introducción: Se han propuesto los umbrales de divergencia molecular para distinguir unidades evolutivas recientemente separadas, que a menudo muestran asignaciones de especies putativas más precisas en la investigación taxonómica en comparación con los enfoques morfológicos tradicionales. Esto hace que los Códigos de Barras de ADN sean una herramienta de identificación atractiva para una variedad de invertebrados marinos, especialmente para complejos de especies crípticas. Aunque GenBank y Barcode of Life Data System (BOLD) son los principales repositorios de secuencias en todo el mundo, muy pocos han probado su desempeño en la identificación de secuencias de equinodermos. Objetivo: Utilizamos secuencias de equinodermos COI de muestras locales y las plataformas de identificación molecular de GenBank y BOLD, para probar su precisión y confiabilidad en la implementación de códigos de barras de ADN para equinodermos de aguas someras de Centroamérica, a nivel de género y especie. Métodos: Realizamos muestreo, extracción de tejido, amplificación de COI, secuenciación e identificación taxonómica de 475 especímenes. Las 348 secuencias obtenidas fueron consultadas individualmente con BLAST en GenBank así como utilizando el Sistema de Identificación (IDS) en BOLD. Las secuencias consultadas se clasificaron según el mejor resultado de coincidencia. Se realizaron las pruebas chi-cuadrado de McNemar, Kruskal-Wallis y U de Mann-Whitney para comprobar diferencias entre los resultados de ambas bases de datos. Además, registramos una lista actualizada de especies reportadas para las aguas someras del Pacífico Centroamericano. Resultados: Encontramos 324 especies de equinodermos reportadas para aguas someras (< 200 m) del Pacífico centroamericano. Sólo 118 y 110 estaban presentes en las bases de datos GenBank y BOLD respectivamente. Propusimos 325 identidades resueltas basadas en morfología y 21 identificaciones provisionales en 50 taxones putativos. GenBank recuperó 348 identificaciones de base molecular en 58 especies, incluidas doce identificaciones provisionales en tres taxones. BOLD recuperó 170 identificaciones de COI en 23 especies con una identificación provisional. Sin embargo, 178 secuencias recuperaron términos no coincidentes (en 34 taxones basados en morfología). Sólo 86 secuencias (25 %) se recuperaron como identificaciones correctas y 128 (37 %) como errores de identificación en ambas plataformas. Incluimos 84 secuencias para once especies no representadas en GenBank y 65 secuencias para diez especies ausentes en las bases de datos BOLD Echinoderm COI. La precisión de la identificación usando BLAST (175 identificaciones correctas y 152 incorrectas) fue mayor que con el motor IDS (110 correctas y 218 errores de identificación), por lo tanto, GenBank supera a BOLD (Kruskal-Wallis = 41.625, df = 1, p < 0.001). Conclusiones: Se necesitan muestras adicionales de equinodermos de referencia para mejorar la utilidad de las herramientas de identificación de códigos de barras de ADN evaluadas. Las discordancias de identificación en ambas bases de datos pueden obedecer a parámetros específicos utilizados en cada algoritmo de búsqueda y a las secuencias disponibles. Recomendamos el uso de códigos de barras como fuente de identificación complementaria para las especies de equinodermos de aguas someras del Pacífico centroamericano.

Uncovering the magnitude of African pangolin poaching with extensive nanopore DNA genotyping of seized scales.

Trade in pangolins is illegal, and yet tons of their scales and products are seized at various ports. These large seizures are challenging to process and comprehensively genotype for upstream provenance tracing and species identification for prosecution. We implemented a scalable DNA barcoding pipeline in which rapid DNA extraction and MinION sequencing were used to genotype a substantial proportion of pangolin scales subsampled from 2 record shipments seized in Singapore in 2019 (37.5 t). We used reference sequences to match the scales to phylogeographical regions of origin. In total, we identified 2346 cytochrome b (cytb) barcodes of white-bellied (Phataginus tricuspis) (from 1091 scales), black-bellied (Phataginus tetradactyla) (227 scales), and giant (Smutsia gigantea) (1028 scales) pangolins. Haplotype diversity was higher for P. tricuspis scales (121 haplotypes, 66 novel) than that for P. tetradactyla (22 haplotypes, 15 novel) and S. gigantea (25 haplotypes, 21 novel) scales. Of the novel haplotypes, 74.2% were likely from western and west-central Africa, suggesting potential resurgence of poaching and newly exploited populations in these regions. Our results illustrate the utility of extensively subsampling large seizures and outline an efficient molecular approach for rapid genetic screening that should be accessible to most forensic laboratories and enforcement agencies.

Revelación de la magnitud de la caza furtiva del pangolín africano mediante el genotipo extenso de nanoporos de ADN de escamas incautadas Resumen Aunque el mercado de pangolines es ilegal, se incautan toneladas de sus escamas y productos derivados en varios puertos comerciales. Es un reto procesar estas magnas incautaciones y obtener el genotipo completo para usarlo en la trazabilidad logística ascendente e identificación de la especie y así imponer sanciones. Implementamos una canalización escalable del código de barras de ADN en el cual usamos la extracción rápida de ADN y la secuenciación MinION para obtener el genotipo de una proporción sustancial de las escamas de pangolín submuestreadas en dos cargamentos incautados en 2019 en Singapur (37.5 t). Usamos secuencias referenciales para emparejar las escamas con las regiones filogeográficas de origen. Identificamos en total 2,346 códigos de citocromo b (cytb) del pangolín de vientre blanco (Phataginus tricuspis) (de 1,091 escamas), de vientre negro (P. tetradactyla) (227 escamas) y del pangolín gigante (Smutsia gigantea) (1,028 escamas). La diversidad de haplotipos fue mayor en las escamas de P. tricuspis (121 haplotipos, 66 nuevos) que en las de P. tetradactyla (22 haplotipos, 15 nuevos) y S. gigantea (25 haplotipos, 21 nuevos). De los haplotipos nuevos, el 74.2% probablemente provenía del occidente y centro­occidente de África, lo que sugiere un resurgimiento potencial de la caza furtiva y poblaciones recién explotadas en estas regiones. Nuestros resultados demuestran la utilidad de submuestrear extensivamente las grandes incautaciones y esboza una estrategia molecular eficiente para un análisis genético rápido que debería ser accesible para la mayoría de los laboratorios forenses y las autoridades de aplicación.

Prediction of Early Antidepressant Efficacy in Patients with Major Depressive Disorder Based on Multidimensional Features of rs-fMRI and P11 Gene DNA Methylation: Prédiction de l'efficacité précoce d'un antidépresseur chez des patients souffrant du trouble dépressif majeur d'après les caractéristiques multidimensionnelles de la méthylation de l'ADN du gène P11 et de la IRMf-rs.

OBJECTIVE: This study established a machine learning model based on the multidimensional data of resting-state functional activity of the brain and P11 gene DNA methylation to predict the early efficacy of antidepressant treatment in patients with major depressive disorder (MDD). METHODS: A total of 98 Han Chinese MDD were analysed in this study. Patients were divided into 51 responders and 47 nonresponders according to whether the Hamilton Depression Rating Scale-17 items (HAMD-17) reduction rate was ≥50% after 2 weeks of antidepressant treatment. At baseline, the Illumina HiSeq Platform was used to detect the methylation of 74 CpG sites of the P11 gene in peripheral blood samples. Resting-state functional magnetic resonance imaging (rs-fMRI) scan detected the amplitude of low-frequency fluctuations (ALFF), regional homogeneity (ReHo), and functional connectivity (FC) in 116 brain regions. The least absolute shrinkage and selection operator analysis method was used to perform feature reduction and feature selection. Four typical machine learning methods were used to establish support vector machine (SVM), random forest (RF), Naïve Bayes (NB), and logistic regression (LR) prediction models based on different combinations of functional activity of the brain, P11 gene DNA methylation and clinical/demographic features after screening. RESULTS: The SVM model based on ALFF, ReHo, FC, P11 methylation, and clinical/demographic features showed the best performance, with 95.92% predictive accuracy and 0.9967 area under the receiver operating characteristic curve, which was better than RF, NB, and LR models. CONCLUSION: The multidimensional data features combining rs-fMRI, DNA methylation, and clinical/demographic features can predict the early antidepressant efficacy in MDD.

Sequência didática com aplicação de prática de baixo custo com uso de recursos biotecnológicos / Didactic sequence with application of low-cost practice with the use of biotechnological resources / Secuencia didáctica con aplicación de prácticas de bajo costo con el uso de recursos biotecnológicos

Objetivoaplicar metodologias práticas de biologia no ensino médio em escola estadual de Feira de Santana do período noturno, utilizando a biotecnologia com intuito de proporcionar novas experiências didáticas para jovens e adultos. Método: A abordagem metodológica é de modo qualitativo e descritivo através de relato de experiência, com aplicação de aula prática com materiais de baixo custo sobre a extração de DNA.Resultados: Com relação às dificuldades enfrentadas na Educação Básica, esta forma de metodologia do trabalho realizado mostrou-se produtiva, uma vez que possibilitou um espaço para discussão e troca de experiências dos alunos associando com seu cotidiano. Conclusão: Esta pesquisa mostrou que o uso desta abordagem didática facilitou o entendimento dos conteúdos trabalhados e do diálogo aluno-professor, evidenciando-a como uma ótima ferramenta para ser trabalhada na sala de aula

Objective: to apply practical biology methodologies in high school at a state school in Feira de Santana at night, using biotechnology with the aim of providing new teaching experiences for young people and adults. Methods:The methodological approach is qualitative and descriptive through experience reports, with the application of practical classes with low-cost materials on DNA extraction. Results: In relation to the difficulties faced in Basic Education, this form of work methodology proved to be productive, as itprovided a space for discussion and exchange of students' experiences associated with their daily lives. Conclusion:This research showed that the use of this didactic approach facilitated the understanding of the content covered and the student-teacher dialogue, highlighting it as a great tool to be used in the classroom

Objetivo: aplicar metodologías prácticas de biología en la escuela secundaria en una escuela pública de Feira de Santana en horario nocturno, utilizando la biotecnología con el objetivo de brindar nuevas experiencias de enseñanza a jóvenes y adultos. Métodos: El enfoque metodológico es cualitativo y descriptivo a través de relatos de experiencia, con la aplicación de clases prácticas con materiales de bajo costo sobre extracción de ADN. Resultados: En relación a las dificultades enfrentadas en la Educación Básica, esta forma de metodología de trabajo resultó productiva, ya que brindó un espacio de discusión e intercambio de experiencias de los estudiantes asociadas a su vida cotidiana. Conclusión: Esta investigación demostró que el uso de este enfoque didáctico facilitó la comprensión de los contenidos tratados y el diálogo alumno-profesor, destacándolo como una gran herramienta para ser utilizado en el aula.

ALT-EJ genera rearreglos cromosómicos en respuesta a Etopósido en células humanas con los principales sistemas de reparación de rupturas de doble cadena comprometidos / ALT-EJ originates chromosomal rearrangements in response to Etoposide in human cells with the main DNA double-strand break repair systems compromised

RESUMEN La droga antitumoral Etopósido (ETO) induce rupturas de doble cadena en el ADN (RDC) y promueve el desarrollo de neoplasias secundarias en los pacientes tratados. Dos mecanismos principales, recombinación homóloga (HR) y reunión de extremos no-homólogos clásica (c-NHEJ) reparan las RDC. Cuando HR y c-NHEJ son defectuosas, la vía alternativa de reunión de extremos (alt-EJ) dependiente de PARP-1 está implicada. Se examinó la participación de alt-EJ en la progresión de las RDC inducidas por ETO en la fase G2 de células humanas. Se establecieron células HeLa deficientes en HR (inhibición de cohesina RAD21, HeLa RAD21kd) y su control no-silenciada (HeLa NS). Las células se trataron con ETO en presencia del inhibidor químico de DNA-PKcs (DNA-PKi, c-NHEJ). En ambas líneas celulares, la inducción de RDC (γH2AX+) por ETO en la fase G2 aumentó respecto a sus controles. La reparación incorrecta en células deficientes en DNA-PKcs y RAD21 originó un incremento sinérgico de intercambio de cromátidas y de cromosomas dicéntricos en la primera y segunda metafase, respectivamente. En cambio, la frecuencia de cromosomas dicéntricos se redujo en células deficientes en PARP-1 (HeLa PARP- 1kd) luego del tratamiento con ETO. En células binucleadas HeLa RAD21kd, DNA-PKi/ETO acrecentó el porcentaje de células con ≥20 focos γH2AX en la fase G1-posmitótica y de micronúcleos a las 96 h. Una mayor acumulación en G2/M se observó en HeLa NS tratadas con DNA-PKi/ETO en relación a HeLa RAD21kd a las 8 h. El ciclo celular se reanudó en HeLa NS a las 16 h, sin embargo, la acumulación se mantuvo en HeLa RAD21kd. Los rearreglos cromosómicos obtenidos con DNA-PKcs y RAD21 disfuncionales y su disminución en células HeLa PARP-1kd, sugieren que alt-EJ contribuye a su formación.

ABSTRACT The antitumor drug Etoposide (ETO) induces DNA double-strand breaks (DSB) and is associated with the development of secondary neoplasms in treated patients. DSB are repaired by two main mechanisms, homologous recombination (HR) and classical non-homologous end joining (c-NHEJ). When HR and c-NHEJ are defective, DSB are repaired by the PARP-1-dependent alternative end-joining (alt-EJ) pathway. The involvement of alt-EJ in the progression of DSB induced by ETO in the G2 phase of human cells was analyzed. HeLa cells deficient in HR (cohesin RAD21 inhibition, HeLa RAD21kd) and their nonsilencing control (HeLa NS) were established. Cells were treated with ETO in the presence of a chemical inhibitor of DNA-PKcs (DNA-PKi, c-NHEJ). In both cell lines, ETO-induced DSB (γH2AX+) in G2 phase were increased compared to their controls. The incorrect repair of DSB in DNA-PKcs- and RAD21-deficient cells caused a synergistic augment in chromatid exchanges and dicentric chromosomes in the first and second metaphase, respectively. In contrast, the frequency of dicentric chromosomes was reduced in PARP-1-deficient cells (HeLa PARP-1kd) following ETO treatment. In HeLa RAD21kd binucleated cells, DNA-PKi/ETO increased the percentage of cells with ≥20 γH2AX foci in the G1-postmitotic phase and of micronuclei at 96 h. A greater accumulation in G2/M was observed in HeLa NS treated with DNA-PKi/ ETO compared with HeLa RAD21kd at 8 h. The cell cycle restarted in HeLa NS at 16 h; however, the G2/M accumulation was maintained in HeLa RAD21kd. Chromosomal rearrangements obtained when DNAPKcs and RAD21 were absent and their decrease in HeLa PARP-1kd cells suggest that alt-EJ contributes to their formation.