Denaturing purifications demonstrate that PRC2 and other widely reported chromatin proteins do not appear to bind directly to RNA in vivo.

Polycomb repressive complex 2 (PRC2) is reported to bind to many RNAs and has become a central player in reports of how long non-coding RNAs (lncRNAs) regulate gene expression. Yet, there is a growing discrepancy between the biochemical evidence supporting specific lncRNA-PRC2 interactions and functional evidence demonstrating that PRC2 is often dispensable for lncRNA function. Here, we revisit the evidence supporting RNA binding by PRC2 and show that many reported interactions may not occur in vivo. Using denaturing purification of in vivo crosslinked RNA-protein complexes in human and mouse cell lines, we observe a loss of detectable RNA binding to PRC2 and chromatin-associated proteins previously reported to bind RNA (CTCF, YY1, and others), despite accurately mapping bona fide RNA-binding sites across others (SPEN, TET2, and others). Taken together, these results argue for a critical re-evaluation of the broad role of RNA binding to orchestrate various chromatin regulatory mechanisms.

Role of Radiotherapy and Hormone Therapy in Patients with Node-Positive Locally Advanced Prostate Cancer

New-generation imaging techniques and the increasing use of surgery in high-risk prostate cancer (PCa) allow usto detect many cases of nodal disease at initial diagnosis or after resection. The treatment of PCa with pathologic regional nodeshas evolved from the exclusive use of systemic therapy to its combination with locoregional treatment. It can also represent abenefit in the overall survival. However, the evidence from randomised studies is limited. Thus, we review the most relevantresults in this scenario.Materials and Methods: A literature search was conducted in MEDLINE, PubMed, EMBASE, Clinical-Trials.gov and Webof Science on January 2023 to review node-positive PCa by considering the relevant literature on this topic published with norestrictions on date and language. The search keywords used were “Prostatic Neoplasms” (MeSh) and “Node-positive” (TextWord) and “Radiotherapy” (MeSh) and (“Androgen Antagonists” (MeSh) or “Antineoplastic Agents, Hormonal” (MeSh)), whichare indexed within the Medical Subject Headings database.Results: The management of node-positive PCa has no clear definitive consensus at the initial disease diagnosis or after surgery.However, in this review, we summarise the existing literature for the management of these patients in both scenarios, consideringimaging tests, radiotherapy, hormone therapy and second-generation hormonal treatments.Conclusions: The combination of radiotherapy and androgen-deprivation therapy is the treatment of choice. The addition ofsecond-generation hormone therapy, plus the intensification of radiotherapy schedules, will likely change the treatment paradigm for these patients. (AU)

A median fin derived from the lateral plate mesoderm and the origin of paired fins.

The development of paired appendages was a key innovation during evolution and facilitated the aquatic to terrestrial transition of vertebrates. Largely derived from the lateral plate mesoderm (LPM), one hypothesis for the evolution of paired fins invokes derivation from unpaired median fins via a pair of lateral fin folds located between pectoral and pelvic fin territories1. Whilst unpaired and paired fins exhibit similar structural and molecular characteristics, no definitive evidence exists for paired lateral fin folds in larvae or adults of any extant or extinct species. As unpaired fin core components are regarded as exclusively derived from paraxial mesoderm, any transition presumes both co-option of a fin developmental programme to the LPM and bilateral duplication2. Here, we identify that the larval zebrafish unpaired pre-anal fin fold (PAFF) is derived from the LPM and thus may represent a developmental intermediate between median and paired fins. We trace the contribution of LPM to the PAFF in both cyclostomes and gnathostomes, supporting the notion that this is an ancient trait of vertebrates. Finally, we observe that the PAFF can be bifurcated by increasing bone morphogenetic protein signalling, generating LPM-derived paired fin folds. Our work provides evidence that lateral fin folds may have existed as embryonic anlage for elaboration to paired fins.

Duox is the primary NADPH oxidase responsible for ROS production during adult caudal fin regeneration in zebrafish.

Sustained elevated levels of reactive oxygen species (ROS) have been shown to be essential for regeneration in many organisms. This has been shown primarily via the use of pharmacological inhibitors targeting the family of NADPH oxidases (NOXes). To identify the specific NOXes involved in ROS production during adult caudal fin regeneration in zebrafish, we generated nox mutants for duox, nox5 and cyba (a key subunit of NOXes 1-4) and crossed these lines with a transgenic line ubiquitously expressing HyPer, which permits the measurement of ROS levels. Homozygous duox mutants had the greatest effect on ROS levels and rate of fin regeneration among the single mutants. However, duox:cyba double mutants showed a greater effect on fin regeneration than the single duox mutants, suggesting that Nox1-4 also play a role during regeneration. This work also serendipitously found that ROS levels in amputated adult zebrafish fins oscillate with a circadian rhythm.

Role of Radiotherapy and Hormone Therapy in Patients with Node-Positive Locally Advanced Prostate Cancer.

BACKGROUND: New-generation imaging techniques and the increasing use of surgery in high-risk prostate cancer (PCa) allow us to detect many cases of nodal disease at initial diagnosis or after resection. The treatment of PCa with pathologic regional nodes has evolved from the exclusive use of systemic therapy to its combination with locoregional treatment. It can also represent a benefit in the overall survival. However, the evidence from randomised studies is limited. Thus, we review the most relevant results in this scenario. MATERIALS AND METHODS: A literature search was conducted in MEDLINE, PubMed, EMBASE, Clinical-Trials.gov and Web of Science on January 2023 to review node-positive PCa by considering the relevant literature on this topic published with no restrictions on date and language. The search keywords used were "Prostatic Neoplasms" (MeSh) and "Node-positive" (Text Word) and "Radiotherapy" (MeSh) and ("Androgen Antagonists" (MeSh) or "Antineoplastic Agents, Hormonal" (MeSh)), which are indexed within the Medical Subject Headings database. RESULTS: The management of node-positive PCa has no clear definitive consensus at the initial disease diagnosis or after surgery. However, in this review, we summarise the existing literature for the management of these patients in both scenarios, considering imaging tests, radiotherapy, hormone therapy and second-generation hormonal treatments. CONCLUSIONS: The combination of radiotherapy and androgen-deprivation therapy is the treatment of choice. The addition of second-generation hormone therapy, plus the intensification of radiotherapy schedules, will likely change the treatment paradigm for these patients.

Aerobic glycolysis is important for zebrafish larval wound closure and tail regeneration.

The underlying mechanisms of appendage regeneration remain largely unknown and uncovering these mechanisms in capable organisms has far-reaching implications for potential treatments in humans. Recent studies implicate a requirement for metabolic reprogramming reminiscent of the Warburg effect during successful appendage and organ regeneration. As changes are thus predicted to be highly dynamic, methods permitting direct, real-time visualisation of metabolites at the tissue and organismal level would offer a significant advance in defining the influence of metabolism on regeneration and healing. We sought to examine whether glycolytic activity was altered during larval fin regeneration, utilising the genetically encoded biosensor, Laconic, enabling the spatiotemporal assessment of lactate levels in living zebrafish. We present evidence for a rapid increase in lactate levels within min following injury, with a role of aerobic glycolysis in actomyosin contraction and wound closure. We also find a second wave of lactate production, associated with overall larval tail regeneration. Chemical inhibition of glycolysis attenuates both the contraction of the wound and regrowth of tissue following tail amputation, suggesting aerobic glycolysis is necessary at two distinct stages of regeneration.

Selective Inhibition of Heparan Sulphate and Not Chondroitin Sulphate Biosynthesis by a Small, Soluble Competitive Inhibitor.

The glycosaminoglycan, heparan sulphate (HS), orchestrates many developmental processes. Yet its biological role has not yet fully been elucidated. Small molecule chemical inhibitors can be used to perturb HS function and these compounds provide cheap alternatives to genetic manipulation methods. However, existing chemical inhibition methods for HS also interfere with chondroitin sulphate (CS), complicating data interpretation of HS function. Herein, a simple method for the selective inhibition of HS biosynthesis is described. Using endogenous metabolic sugar pathways, Ac4GalNAz produces UDP-GlcNAz, which can target HS synthesis. Cell treatment with Ac4GalNAz resulted in defective chain elongation of the polymer and decreased HS expression. Conversely, no adverse effect on CS production was observed. The inhibition was transient and dose-dependent, affording rescue of HS expression after removal of the unnatural azido sugar. The utility of inhibition is demonstrated in cell culture and in whole organisms, demonstrating that this small molecule can be used as a tool for HS inhibition in biological systems.

Matriptase activation of Gq drives epithelial disruption and inflammation via RSK and DUOX.

Epithelial tissues are primed to respond to insults by activating epithelial cell motility and rapid inflammation. Such responses are also elicited upon overexpression of the membrane-bound protease, Matriptase, or mutation of its inhibitor, Hai1. Unrestricted Matriptase activity also predisposes to carcinoma. How Matriptase leads to these cellular outcomes is unknown. We demonstrate that zebrafish hai1a mutants show increased H2O2, NfκB signalling, and IP3R -mediated calcium flashes, and that these promote inflammation, but do not generate epithelial cell motility. In contrast, inhibition of the Gq subunit in hai1a mutants rescues both the inflammation and epithelial phenotypes, with the latter recapitulated by the DAG analogue, PMA. We demonstrate that hai1a has elevated MAPK pathway activity, inhibition of which rescues the epidermal defects. Finally, we identify RSK kinases as MAPK targets disrupting adherens junctions in hai1a mutants. Our work maps novel signalling cascades mediating the potent effects of Matriptase on epithelia, with implications for tissue damage response and carcinoma progression.

Cancer occurs when normal processes in the cell become corrupted or unregulated. Many proteins can contribute, including one enzyme called Matriptase that cuts other proteins at specific sites. Matriptase activity is tightly controlled by a protein called Hai1. In mice and zebrafish, when Hai1 cannot adequately control Matriptase activity, invasive cancers with severe inflammation develop. However, it is unclear how unregulated Matriptase leads to both inflammation and cancer invasion. One outcome of Matriptase activity is removal of proteins called Cadherins from the cell surface. These proteins have a role in cell adhesion: they act like glue to stick cells together. Without them, cells can dissociate from a tissue and move away, a critical step in cancer cells invading other organs. However, it is unknown exactly how Matriptase triggers the removal of Cadherins from the cell surface to promote invasion. Previous work has shown that Matriptase switches on a receptor called Proteinase-activated receptor 2, or Par2 for short, which is known to activate many enzymes, including one called phospholipase C. When activated, this enzyme releases two signals into the cell: a sugar called inositol triphosphate, IP3; and a lipid or fat called diacylglycerol, DAG. It is possible that these two signals have a role to play in how Matriptase removes Cadherins from the cell surface. To find out, Ma et al. mapped the effects of Matriptase in zebrafish lacking the Hai1 protein. This revealed that Matriptase increases IP3 and DAG levels, which initiate both inflammation and invasion. IP3 promotes inflammation by switching on pro-inflammatory signals inside the cell such as the chemical hydrogen peroxide. At the same time, DAG promotes cell invasion by activating a well-known cancer signalling pathway called MAPK. This pathway activates a protein called RSK. Ma et al. show that this protein is required to remove Cadherins from the surface of cells, thus connecting Matriptase's activation of phospholipase C with its role in disrupting cell adhesion. An increase in the ratio of Matriptase to HAI-1 (the human equivalent of Hai1) is present in many cancers. For this reason, the signal cascades described by Ma et al. may be of interest in developing treatments for these cancers. Understanding how these signals work together could lead to more direct targeted anti-cancer approaches in the future.

Dosimetric influence of deformable image registration uncertainties on propagated structures for online daily adaptive proton therapy of lung cancer patients.

PURPOSE: A major burden of introducing an online daily adaptive proton therapy (DAPT) workflow is the time and resources needed to correct the daily propagated contours. In this study, we evaluated the dosimetric impact of neglecting the online correction of the propagated contours in a DAPT workflow. MATERIAL AND METHODS: For five NSCLC patients with nine repeated deep-inspiration breath-hold CTs, proton therapy plans were optimised on the planning CT to deliver 60 Gy-RBE in 30 fractions. All repeated CTs were registered with six different clinically used deformable image registration (DIR) algorithms to the corresponding planning CT. Structures were propagated rigidly and with each DIR algorithm and reference structures were contoured on each repeated CT. DAPT plans were optimised with the uncorrected, propagated structures (propagated DAPT doses) and on the reference structures (ideal DAPT doses), non-adapted doses were recalculated on all repeated CTs. RESULTS: Due to anatomical changes occurring during the therapy, the clinical target volume (CTV) coverage of the non-adapted doses reduces on average by 9.7% (V95) compared to an ideal DAPT doses. For the propagated DAPT doses, the CTV coverage was always restored (average differences in the CTV V95 < 1% compared to the ideal DAPT doses). Hotspots were always reduced with any DAPT approach. CONCLUSION: For the patients presented here, a benefit of online DAPT was shown, even if the daily optimisation is based on propagated structures with some residual uncertainties. However, a careful (offline) structure review is necessary and corrections can be included in an offline adaption.

Reactive oxygen species during heart regeneration in zebrafish: Lessons for future clinical therapies.

In humans, myocardial infarction (MI) is associated with irreversible damage to heart tissue, resulting in increased morbidity and mortality in patients. By comparison, the zebrafish (Danio rerio) is capable of repairing damaged and injured hearts by activating a full regenerative response. By studying model organisms that can regenerate loss heart tissue following injury, such as the zebrafish, a greater insight will be gained into the molecular pathways that can induce and sustain a regenerative response following injury. There is hope that such information may lead to new treatments or therapies aimed at stimulating a better regenerative response in humans that have suffered heart attacks. Recent findings in zebrafish have highlighted an important role for sustained elevated levels of Reactive Oxygen Species (ROS), including hydrogen peroxide (H2 O2 ) in the promotion of a regenerative response. Given that elevated levels of H2 O2 can be harmful, simply elevating ROS levels directly may not be easy or practical to translate clinically. An alternative approach would be to identify the critical downstream targets of ROS in the promotion of heart regeneration, and then target these clinically using drugs. One such family of potential downstream targets of ROS during heart regeneration are the family of protein tyrosine phosphatases (PTPs), which are known to be exquisitely sensitive to redox regulation and whose inhibition have been linked to the promotion of heart regeneration in zebrafish. In this review, we present an overview of the zebrafish as a model organism for studying cardiac regeneration, including the molecular mechanisms by which cardiac regeneration occurs in response to injury. We then present recent findings linking elevated ROS levels to heart regeneration and their potential downstream targets, the PTPs, including protein tyrosine phosphatase 1B (PTP1B) and the dual specificity phosphatase 6 (DUSP6) in the promotion of heart regeneration.

How to Grow Xenopus laevis Tadpole Stages to Adult.

In Xenopus laevis, the tadpole stage is characterized by three forms-those occurring before the initiation of limb development, those covering limb development, and those encompassing metamorphosis. Maximal tadpole growth, especially during the second form, is critically dependent on good husbandry practices. Here we describe a protocol for raising Xenopus laevis tadpoles through to adulthood. Each step may need to be modified depending on the aquaria used and local conditions.

Model systems for regeneration: Xenopus.

Understanding how to promote organ and appendage regeneration is a key goal of regenerative medicine. The frog, Xenopus, can achieve both scar-free healing and tissue regeneration during its larval stages, although it predominantly loses these abilities during metamorphosis and adulthood. This transient regenerative capacity, alongside their close evolutionary relationship with humans, makes Xenopus an attractive model to uncover the mechanisms underlying functional regeneration. Here, we present an overview of Xenopus as a key model organism for regeneration research and highlight how studies of Xenopus have led to new insights into the mechanisms governing regeneration.

Zebrafish duox mutations provide a model for human congenital hypothyroidism.

Thyroid dyshormonogenesis is a leading cause of congenital hypothyroidism, a highly prevalent but treatable condition. Thyroid hormone (TH) synthesis is dependent on the formation of reactive oxygen species (ROS). In humans, the primary sources for ROS production during thyroid hormone synthesis are the NADPH oxidases DUOX1 and DUOX2. Indeed, mutations in DUOX1 and DUOX2 have been linked with congenital hypothyroidism. Unlike humans, zebrafish has a single orthologue for DUOX1 and DUOX2 In this study, we investigated the phenotypes associated with two nonsense mutant alleles, sa9892 and sa13017, of the single duox gene in zebrafish. Both alleles gave rise to readily observable phenotypes reminiscent of congenital hypothyroidism, from the larval stages through to adulthood. By using various methods to examine external and internal phenotypes, we discovered a strong correlation between TH synthesis and duox function, beginning from an early larval stage, when T4 levels are already noticeably absent in the mutants. Loss of T4 production resulted in growth retardation, pigmentation defects, ragged fins, thyroid hyperplasia/external goiter and infertility. Remarkably, all of these defects associated with chronic congenital hypothyroidism could be rescued with T4 treatment, even when initiated when the fish had already reached adulthood. Our work suggests that these zebrafish duox mutants may provide a powerful model to understand the aetiology of untreated and treated congenital hypothyroidism even in advanced stages of development.This article has an associated First Person interview with the first author of the paper.

Investigating the Cellular and Molecular Mechanisms of Wound Healing in Xenopus Oocytes and Embryos.

The African clawed frog Xenopus has remarkable capacities to heal wounds rapidly and to regenerate complex tissues. Because of its experimental tractability, studies using Xenopus oocytes, embryos, and larvae have contributed extensively to our understanding of the molecular and cellular mechanisms underpinning wound healing and tissue regeneration. In this protocol, we describe wound-healing assays following mechanical or laser injuries of oocytes and multicellular epithelia in Xenopus laevis embryos. We also explain how to perform assays aimed at investigating the cellular and molecular events during wound healing, including gene knockdown and overexpression experiments. In the latter assays, we explore the use of biochemical pull-down assays to investigate the activity of Rho GTPases, as well as the injection of mRNAs encoding fluorescent proteins or probes, followed by quantitative confocal image analyses to assay the dynamics of cytoskeletal components and their regulators.

Ca2+-Induced Mitochondrial ROS Regulate the Early Embryonic Cell Cycle.

While it is appreciated that reactive oxygen species (ROS) can act as second messengers in both homeostastic and stress response signaling pathways, potential roles for ROS during early vertebrate development have remained largely unexplored. Here, we show that fertilization in Xenopus embryos triggers a rapid increase in ROS levels, which oscillate with each cell division. Furthermore, we show that the fertilization-induced Ca2+ wave is necessary and sufficient to induce ROS production in activated or fertilized eggs. Using chemical inhibitors, we identified mitochondria as the major source of fertilization-induced ROS production. Inhibition of mitochondrial ROS production in early embryos results in cell-cycle arrest, in part, via ROS-dependent regulation of Cdc25C activity. This study reveals a role for oscillating ROS levels in early cell cycle regulation in Xenopus embryos.

The role of immunonutritional support in cancer treatment: Current evidence.

The significant role of the immune system in cancer treatment has given rise to an emerging field of study within oncology, and one that is attracting increasing attention from researchers. Immunotherapy has demonstrated that the immune system is crucial in the fight against cancer. This challenge has led researchers to analyze whether the immune influencing capacity of immunonutrition may aid in improving immune status, modulate the acquired immune response, decrease the treatment toxicity and improve patient outcomes. Immunonutrition, new developed formulas has been demonstrated to improve outcome in surgical patients. This improvement is related to the modulation of the inflammatory response in the peri-operative period. The aim of this review is to analyze current evidence on the benefit of immunonutrition in patients undergoing pro-inflammatory processes in cancer, such as receiving chemotherapy or radiation treatment. With this aim, authors have analyzed the problem studying different aspects: the role of the immune system in cancer treatment, current evidence regarding immunonutrition in perioperative period, current evidence regarding immunonutrition in cancer patients and the relation between immunity and radiotherapy. The conclusions of this review confirm that immunonutrition formulas could modulate inflammatory and immune response in cancer patients. This effect decreases acute toxicity, although the pathways and the measure of this immune response are unclear. Immunonutrition is an emerging field in oncology, and further research is needed.

The cellular and molecular mechanisms of tissue repair and regeneration as revealed by studies in Xenopus.

Survival of any living organism critically depends on its ability to repair and regenerate damaged tissues and/or organs during its lifetime following injury, disease, or aging. Various animal models from invertebrates to vertebrates have been used to investigate the molecular and cellular mechanisms of wound healing and tissue regeneration. It is hoped that such studies will form the framework for identifying novel clinical treatments that will improve the healing and regenerative capacity of humans. Amongst these models, Xenopus stands out as a particularly versatile and powerful system. This review summarizes recent findings using this model, which have provided fundamental knowledge of the mechanisms responsible for efficient and perfect tissue repair and regeneration.

Seeing is believing.

A small transparent crustacean called Parhyale hawaiensis has become a powerful model system for the study of limb and appendage regeneration.

Assessing Primary Neurogenesis in Xenopus Embryos Using Immunostaining.

Primary neurogenesis is a dynamic and complex process during embryonic development that sets up the initial layout of the central nervous system. During this process, a portion of neural stem cells undergo differentiation and give rise to the first populations of differentiated primary neurons within the nascent central nervous system. Several vertebrate model organisms have been used to explore the mechanisms of neural cell fate specification, patterning, and differentiation. Among these is the African clawed frog, Xenopus, which provides a powerful system for investigating the molecular and cellular mechanisms responsible for primary neurogenesis due to its rapid and accessible development and ease of embryological and molecular manipulations. Here, we present a convenient and rapid method to observe the different populations of neuronal cells within Xenopus central nervous system. Using antibody staining and immunofluorescence on sections of Xenopus embryos, we are able to observe the locations of neural stem cells and differentiated primary neurons during primary neurogenesis.

[NUTRIENTS AND RADIOTHERAPY; REVIEW OF THE LITERATURE]. / NUTRIENTES Y RADIOTERAPIA; REVISIÓN DE LA LITERATURA.

INTRODUCTION: nutrition is an important influence on treatments and quality of life of cancer patients. The relationship between different nutritional components and radiotherapy is today a topic of growing interest. OBJECTIVE: to evaluate the influence of macro and micronutrients on tolerance and effectiveness of radiotherapy and their role in modulating chronic toxicity. MATERIALS AND METHODS: we performed a research of the published literature by consulting the MEDLINE database and Cochrane Library online between 1995 and 2015, relevant publications based on impact factor were selected. Data from the analyzed studies were exposed in sections by type of nutrient. RESULTS: most of the studies showed common features: small sample sizes, high heterogeneity, underpowered results and few prospective randomized studies. In the section of fiber, its use in prophylaxis and treatment of radiation enteritis has been successfully evaluated in some studies, although evidence of its recommendation is still weak. Omega 3 and omega 6 fatty acids have a high metabolic potential, however the evidence regarding this benefit is limited to observational studies in certain tumors. Among the amino acids, glutamine is the most studied, and controversial results of its effect on mucositis, esophagitis and radiation enteritis were found. Vitamins and minerals are a heterogeneous group of substances that showed potential benefit due to their antioxidant activity and their supposed protector effect against toxicity secondary to radiotherapy. Ketogenic diets are beginning to be clinically studied after promising preclinical results. CONCLUSIONS: the analyzed studies show controversial or inconclusive results regarding the influence of nutrients in the radiotherapy. It has been not found Sorong evidence about their role in patients receiving ionizing radiation. Well-designed, prospective and randomized studies are needed to establish recommendations.

Introducción: la nutrición ejerce una importante influencia sobre los tratamientos y la calidad de vida del paciente oncológico. En la actualidad, la relación de los distintos componentes nutricionales con el tratamiento radioterápico es un tema de creciente interés. Objetivos: evaluar la posible influencia de los macro y micronutrientes sobre la tolerancia y eficacia del tratamiento radioterápico, así como su papel en la modulación de la toxicidad crónica. Material y métodos: se ha realizado una revisión bibliográfica consultando las bases de datos MEDLINE y Biblioteca Cochrane online entre los años 2000 y 2015, seleccionando los trabajos más relevantes según factor de impacto. Los datos obtenidos de los estudios analizados se han expuesto por apartados según el tipo de nutriente. Resultados: la mayoría de los estudios analizados presentan características comunes: pequeños tamaños muestrales, alta heterogeneidad en estudios de un mismo tema, escaso poder estadístico, pocos estudios prospectivos y aleatorizados. En el apartado de la fibra, su empleo como profilaxis y tratamiento de la enteritis rádica ha sido evaluado con resultados satisfactorios en algunos estudios, aunque la evidencia de su recomendación es todavía débil. Los ácidos grasos omega­3 y omega­6 tienen una gran potencialidad metabólica, aunque la evidencia de su beneficio se limita a estudios observacionales en determinados tumores. Entre los aminoácidos, la glutamina es el más estudiado, con resultados contradictorios en el aporte de beneficio en la mucositis oral, la esofagitis y la enteritis rádica. Las vitaminas y minerales constituyen un grupo heterogéneo de sustancias con beneficio potencial por su actividad antioxidante y su posible efecto protector, disminuyendo la toxicidad producida por la radioterapia. Las dietas cetogénicas están comenzando a estudiarse clínicamente después de los prometedores resultados preclínicos. Conclusiones: los estudios analizados muestran resultados contradictorios o poco concluyentes respecto a la influencia de los nutrientes en el tratamiento radioterápico. No se pueden establecer en la actualidadrecomen daciones claras sobre su papel. Son necesarios estudios prospectivos y aleatorizados, bien diseñados, para poder establecer recomendaciones.