Viral Interference between the Insect-Specific Virus Brejeira and the Saint Louis Encephalitis Virus In Vitro.

The Saint Louis encephalitis virus (SLEV) is an encephalitogenic arbovirus (Flaviviridae family) that has a wide geographical distribution in the western hemisphere, especially in the Americas. The negevirus Brejeira (BREV) was isolated for the first time in Brazil in 2005. This study aimed to verify the existence of a possible interfering effect of BREV on the course of SLEV infection and vice versa. We used clone C6/36 cells. Three combinations of MOIs were used (SLEV 0.1 × BREV 1; SLEV 1 × BREV 0.1; SLEV 1 × BREV 1) in the kinetics of up to 7 days and then the techniques of indirect immunofluorescence (IFA), a plaque assay on Vero cells, and RT-PCR were performed. Our results showed that the cytopathic effect (CPE) caused by BREV was more pronounced than the CPE caused by SLEV. Results of IFA, the plaque assay, and RT-PCR showed the suppression of SLEV replication in the co-infection condition in all the MOI combinations used. The SLEV suppression was dose-dependent. Therefore, the ISV Brejeira can suppress SLEV replication in Aedes albopictus cells, but SLEV does not negatively interfere with BREV replication.

Development and In Vivo Assessment of 4-Phenyltellanyl-7-chloroquinoline-loaded Polymeric Nanocapsules in Alzheimer's Disease Models.

Alzheimer's disease (AD) is the most common form of dementia in older people, and available treatments are palliative and produce undesirable side effects. The 4-phenyltellanyl-7-chloroquinoline (TQ) is an organochalcogen compound studied due to its pharmacological properties, particularly its antioxidant potential. However, TQ possesses some drawbacks such as low aqueous solubility and high toxicity, thus warranting the search for tools that improve the safety and effectiveness of new compounds. Here, we developed and investigated the biological effects of TQ-loaded polymeric nanocapsules (NCTQ) in an AD model in transgenic Caenorhabditis elegans expressing human Aß1-42 in their body-wall muscles and Swiss mice injected with Aß25-35. The NCTQ displayed good physicochemical properties, including nanometer size and maximum encapsulation capacity. The treatment showed low toxicity, reduced Aß peptide-induced paralysis, and activated an endoplasmic reticulum chaperone in the C. elegans model. The Aß injection in mice caused memory impairment, which NCTQ mitigated by improving working, long-term, and aversive memory. Additionally, no changes in biochemical markers were evidenced in mice, demonstrating that there was no hepatotoxicity in the tested doses. Altogether, these findings provide insights into the neuroprotective effects of TQ and indicate that NCTQ is a promising candidate for AD treatment.

Clozapine-loaded nanocapsules improve antipsychotic activity in rats: building a sequential PopPK/PD model to discriminate nanocarriers in the preformulation step.

PURPOSE: We investigated the impact of nanoformulations on the dose-exposure-response relationship of clozapine (CZP), a low-solubility antipsychotic with serious adverse effects, using a popPK/PD approach. METHODS: We evaluated the pharmacokinetics and PK/PD profiles of three coated polymeric CZP-loaded nanocapsules functionalized with polysorbate 80 (NCP80), polyethylene glycol (NCPEG), and chitosan (NCCS). Data on in vitro CZP release by dialysis bag, plasma pharmacokinetic profiles in male Wistar rats (n = 7/group, 5 mg kg-1, i.v.), and percentage of head movements in a stereotyped model (n = 7/group, 5 mg kg-1, i.p.) were integrated using a sequential model building approach (MonolixSuiteTM-2020R1-Simulation Plus). RESULTS: A base popPK model developed with CZP solution data collected after the i.v. administration of CZP was expanded to describe the changes in drug distribution caused by nanoencapsulation. Two additional compartments were inserted into the NCP80 and NCPEG models, and a third compartment was included in the NCCS model. The nanoencapsulation showed a decrease in the central volume of distribution for NCCS (V1NCpop = 0.21 mL), while for FCZP, NCP80, and NCPEG, it was ~1 mL. The peripheral distribution volume was higher for the nanoencapsulated groups (19.1 and 129.45 mL for NCCS and NCP80, respectively) than for FCZP. The popPK/PD model showed a formulation-dependent plasma IC50, with 20-, 50-, and 80-fold reductions compared to the CZP solution (NCP80, NCPEG, and NCCS, respectively). CONCLUSION: Our model discriminates the coatings and describes the peculiar PK and PD behavior of nanoencapsulated CZP, especially NCCS, making it an exciting tool for evaluating the preclinical performance of nanoparticles.

Safety assessment of different unloaded polymeric nanocapsules in Caenorhabditis elegans.

Nano-sized drug delivery systems have been the subject of intense research in recent years because polymeric materials allow the absorption and release of active substances in a controlled manner. Despite the benefits, the safety of nanoparticulate systems is an aspect to be understood, particularly in vivo systems. Caenorhabditis elegans is a very useful alternative model for nanotoxicology and has been recently applied in this field. The aim of this study was to evaluate toxicological endpoints in C. elegans exposed to nanocapsules (NC) prepared with different coatings: polysorbate 80 (NCP80); polyethylene glycol (NCPEG), Eudragit® RS 100 (NCEUD) and chitosan (NCCS). Nanocapsules were prepared by nanoprecipitation method and showed acceptable physico-chemical characterization. Polyethylene glycol nanocapsules and chitosan nanocapsules increased worms lethality in a dose-dependent manner in acute exposure; polysorbate 80 nanocapsules, polyethylene glycol nanocpsules and chitonan nanocapsules also increased lethality following chronic exposure. Chitosan nanocapsules were the most toxic in all exposures, demonstrating toxicity even at low concentrations. Reproduction and body length were not affected by any of the nanocapsules exposures. The expression of superoxide dismutase showed that polysorbate 80 nanocapsules at the highest concentration slightly increased SOD-3::GFP expression. On the other hand, chitosan nanocapsules exposure blunted SOD-3 expression. This work demonstrates the toxicological differences between nanocapsule produced with different coatings and indicates higher safety for the use of eugragit nanocapsule in new formulations for future drug delivery and targeting systems.

In vivo and in vitro per se effect evaluation of Polycaprolactone and Eudragit® RS100-based nanoparticles.

Biodegradable polymeric nanocapsules (NC) present incredible characteristics as drug nanocarriers that optimize drug targeting. However, However, a more detailed isolated effect of polymer-based nanoparticles as drug carriers is required. This work aimed to evaluate the per se effect of blank-NC (NC-B) with different surface characteristics both in vitro and in vivo toxicity. NC1-B (Polysorbate 80 coated poly(ɛ-caprolactone) NC), NC2-B (polyethylene glycol 6000 coated poly(ɛ-caprolactone) NC), NC3-B (chitosan-coated poly(ɛ-caprolactone) NC) and NC4-B (Eudragit® RS100 NC) were prepared by nanoprecipitation method. Formulations were characterized by particle size, zeta potential, and pH. The in vitro cytotoxicity tests against tumor cell lines were performed (HepG2 and MCF-7). Antiviral activity was evaluated by MTT in Vero cells infected with HSV-1 (KOS strain). In vivo evaluation was performed in apomorphine-induced stereotypy in Wistar rats and locomotor activity distance, head movements, and rearing behavior were measured. NC1-B, NC2-B, NC3-B, and NC4-B had a diameter under 350 nm. The pH and zeta potential of formulations varied according to their coating. For in vitro evaluation of antitumor activity and antiviral activity, one-way ANOVA showed no significant differences in cell viability. In vivo tests showed low neurological effects. In conclusion, different surface characteristics of NC-B did not demonstrate toxicity against the evaluated cell lines HepG2 and MCF-7, antiviral effect against HSV-1, and the neurological effects in a stereotyping model were low and may be attributed to the per se effect of NC-B.

Discovery and genome sequencing of a new virus related to members of the family Tymoviridae, isolated from mosquitoes of the genus Mansonia in Brazil.

A new virus, named Mutum virus, related to members of the family Tymoviridae, was isolated from mosquitoes (Mansonia spp.) in clone C6/36 cells, and its complete genome was sequenced. Its genome is 6494 nt in size with an organization resembling that of tymovirids. The isolated virus is phylogenetically related to two viruses isolated from Culex spp. mosquitoes: Ek Balam virus, reported in Mexico, and Culex-originated Tymoviridae-like virus, isolated in China. The results of this study suggest that this virus is a new member of the family Tymoviridae.

Absence of Anti-RBD Antibodies in SARS-CoV-2 Infected or Naive Individuals Prior to Vaccination with CoronaVac Leads to Short Protection of Only Four Months Duration.

The COVID-19 pandemic is the biggest public health threat facing the world today. Multiple vaccines have been approved; however, the emergence of viral variants such as the recent Omicron raises the possibility of booster doses to achieve adequate protection. In Brazil, the CoronaVac (Sinovac, Beijing, China) vaccine was used; however, it is important to assess the immune response to this vaccine over time. This study aimed to monitor the anti-SARS-CoV-2 antibody responses in those immunized with CoronaVac and SARS-CoV-2 infected individuals. Samples were collected between August 2020 and August 2021. Within the vaccinated cohort, some individuals had a history of infection by SARS-CoV-2 prior to immunization, while others did not. We analyzed RBD-specific and neutralizing-antibodies. Anti-RBD antibodies were detected in both cohorts, with a peak between 45-90 days post infection or vaccination, followed by a steady decline over time. In those with a previous history of COVID-19, a higher, longer, more persistent response was observed. This trend was mirrored in the neutralization assays, where infection, followed by immunization, resulted in higher, longer lasting responses which were conditioned on the presence of levels of RBD antibodies right before the vaccination. This supports the necessity of booster doses of CoronaVac in due course to prevent serious disease.

Negeviruses isolated from mosquitoes in the Brazilian Amazon.

BACKGROUND: There are several groups of viruses including Insect Specific Viruses (ISV) such as the taxon Negevirus, a group of viruses phylogenetically related to plant viruses. Negeviruses replicate in mosquito cells, but not in vertebrate cells. METHODS: Pools of hematophagous arthropods were inoculated in Vero and C6/36 cells. The cells were observed to detect possible cytopathic effect. Then, indirect immunofluorescence, RT-PCR, and nucleotide sequencing were performed. RESULTS: Seven samples which presented negative results for flaviviruses, alphaviruses and bunyaviruses, but showed cytopathic effect in C6/36 cells were sequenced. We identified the occurrence of a variety of ISVs, most of them belonging to the taxon Negevirus: The Brejeira, Negev, Cordoba and Wallerfield viruses, including a new virus for science, tentatively named Feitosa virus. CONCLUSIONS: We detected negeviruses in the Amazon region, including two viruses that were isolated for the first time in Brazil: Cordoba virus and the Negev virus and, a new virus for science: the Feitosa virus.

Surface-functionalized curcumin-loaded polymeric nanocapsules could block apomorphine-induced behavioral changes in rats.

BACKGROUND: Surface functionalization enhances the properties and characteristics of polymeric nanocapsules (NCs) mainly due to the surface charge, surfactants, and polymer coating type. Curcumin (CUR) is a bioactive compound with several proven pharmacological properties and low bioavailability. This study aimed to develop anionic (poly-ɛ-caprolactone; PCL) and cationic (Eudragit® RS100 (EUD)) NCs prepared with sorbitan monostearate (Span 60®) or sorbitan monooleate (Span 80®), coated with d-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and optimized using 23 factorial analysis. Subsequently, the biological activity was evaluated. METHODS: A two-level, three-factor design (polymer, Span type, and TPGS concentration) was used. The biological effects of CUR-loaded TPGS-coated cationic and anionic NCs were assessed in apomorphine-induced stereotyped behavior in rats. RESULTS: The type of polymer (anionic or cationic) and Span® had a factorial influence on the physical and chemical characteristics of NCs according to the changes in TPGS concentrations. Both cationic and anionic CUR-NCs could block apomorphine-induced behavioral changes. CONCLUSIONS: The CUR-loaded TPGS-coated NCs proved to be a promising brain delivery system.

Trends in Corneal Transplantation in a Tertiary Hospital in Brazil.

PURPOSE: The purpose of this study was to analyze the evolving trends of surgical techniques and indications of corneal transplantation (CT) at a tertiary hospital in Brazil. METHODS: The medical records of all patients who underwent CT at the Hospital Oftalmológico de Sorocaba (Sorocaba Eye Hospital) from the Banco de Olhos de Sorocaba (Sorocaba Eye Bank) group in Sorocaba, Brazil, from January 1, 2012, to December 31, 2019, were analyzed. Data regarding age, sex, transplant indication, and surgical technique were collected. RESULTS: A total of 16,250 CTs were performed. There was a statistically significant decreasing trend of keratoconus-related CT ( P < 0.0001), with rates dropping from 41.7% among all CTs in 2012 to 25.5% in 2019. Penetrating keratoplasty, anterior lamellar keratoplasty, and endothelial keratoplasty (EK) accounted for 59.3%, 27.1%, and 7.8% of the CTs performed in 2012 and 33.3%, 16.4%, and 39.9% in 2019, respectively. A statistically significant decreasing trend was observed for penetrating keratoplasty ( P < 0.0001) and anterior lamellar keratoplasty ( P < 0.0001), whereas EK showed a statistically significant increasing trend during the period ( P < 0.0001). Among EKs, Descemet membrane EK increased statistically significantly from 12.8% in 2012 to 74.4% in 2019 ( P < 0.0001). CONCLUSIONS: This study shows relevant evolving trends in indications and preferred CT techniques in a tertiary hospital in Brazil.

The accentuation in post-traumatic stress disorder-like symptoms induced by diabetes in rats is not associated with a further increase in astrocyte activation in the hippocampus.

Individuals with post-traumatic stress disorder (PTSD) show increased rates of several serious metabolic diseases. However, little is known about pre-existing metabolic diseases and the development of PTSD. Therefore, we aimed to evaluate the course of post-traumatic stress disorder (PTSD) development in rats with preexisting diabetes. In addition, we quantified glial fibrillary acidic protein (GFAP) in the hippocampus of the experimental animals. For this, we used male Wistar rats and divided them into two groups: saline and alloxan (150 mg/Kg, i.p.). The animals were weighed, and plasma glucose was measured after 48 h of diabetes induction by alloxan. The animals were either exposed to inescapable footshocks or not, followed by social isolation. After 14 days, the animals were re-exposed to the box, and the freezing time was evaluated for 10 min. Over the following days, the animals were tested on the open field, social interaction and forced swimming tests. In another group of animals, elevated plus maze and object recognition tests were performed. Our results demonstrated that animals with diabetes had more pronounced PTSD-like symptoms as a reduction in social interaction, an increase in immobility time in forced swimming, a reduction in permanence in the open arms of the elevated plus maze, and a deficit in the object recognition index more accentuated. However, this did not reflect astrocyte activation in the hippocampus. In conclusion, diabetes accentuates post-traumatic stress disorder-like symptoms but not astrocyte activation in the hippocampus.

Maternal overweight induced by reduced litter size impairs the behavioral neurodevelopment of offspring.

AIMS: We assessed the influence of maternal overweight on the behavioral neurodevelopment of male and female offspring in prepubertal age by reducing the litter size. MAIN METHODS: To reduce litter size in Wistar rats, the offspring of generation 0 (G0) were culled for 12 pups (6 males and 6 females: normal litter, NL-G1) or 4 pups (2 males and 2 females: small litter, SL-G1). In G1 dams, overweight was characterized, maternal behavior and locomotor activity were assessed. At G2, we quantified the ultrasonic vocalizations in post-natal day 5 (PND5); we evaluated olfactory discrimination in the homing behavior test on PND13; and in PND28-32 (prepubertal age), we performed the following tests: social play behavior, hole board, object recognition, and open field. At the end of the experiments, hippocampus and prefrontal cortex were dissected to quantify the synaptophysin by western blotting. KEY FINDINGS: Our data demonstrated that a reduction in litter size was able to induce maternal overweight without altering the parameters related to overweight in the offspring. The SL-G2 offspring showed deficits in early social communication, olfactory discrimination, social play behavior, and the exploration of objects, in addition to increasing repetitive and stereotyped movements. There were also changes in the synaptophysin levels in the hippocampus and prefrontal cortex of the offspring from reduced litter dams. In conclusion, maternal overweight caused by litter reduction impairs behavioral neurodevelopment, inducing autism-like symptoms in the offspring. SIGNIFICANCE: This study alerts the public about the negative consequences of maternal overweight in the descendants.

Revisiting cell and gene therapies in Huntington's disease.

Neurodegenerative movement disorders, such as Huntington's disease (HD), share a progressive and relentless course with increasing motor disability, linked with neuropsychiatric impairment. These diseases exhibit diverse pathophysiological processes and are a topic of intense experimental and clinical research due to the lack of therapeutic options. Restorative therapies are promising approaches with the potential to restore brain circuits. However, there were less compelling results in the few clinical trials. In this review, we discuss cell replacement therapies applied to animal models and HD patients. We thoroughly describe the initial trials using fetal neural tissue transplantation and recent approaches based on alternative cell sources tested in several animal models. Stem cells were shown to generate the desired neuron phenotype and/or provide growth factors to the degenerating host cells. Besides, genetic approaches such as RNA interference and the CRISPR/Cas9 system have been studied in animal models and human-derived cells. New genetic manipulations have revealed the capability to control or counteract the effect of human gene mutations as described by the use of antisense oligonucleotides in a clinical trial. In HD, innovative strategies are at forefront of human testing and thus other brain genetic diseases may follow similar therapeutic strategies.

Evaluation of curcumin-loaded polymeric nanocapsules with different coatings in chick embryo model: influence on angiogenesis, teratogenesis and oxidative stress.

BACKGROUND: Curcumin (CUR) is a bioactive compound with several proven pharmacological properties. However, the major limitation for therapeutic use of CUR is its low bioavailability. In this sense, an alternative to this question is the use of polymeric nanocapsules (NC) as drug/nutraceutical delivery systems. Thus, the aim of current study was to assess the effect of CUR-loaded NC and their different coatings in chick embryo model, evaluating angiogenic, teratogenic and oxidative stress parameters. METHODS: The physicochemical characterization of unloaded and loaded NC with different coatings: (U-NC (P80), U-NC (PEG), U-NC (EUD), U-NC (CS), CUR-NC (P80), CUR-NC (PEG), CUR-NC (EUD) and CUR-NC (CS)) were performed. After 9 days of incubation, eggs were treated (10 mL/kg eggs; via injection) with NC (unloaded and loaded with CUR) and CUR-solution. In sequence, hen's egg test-chorioallantoic membrane (HET-CAM), angiogenic assay, external abnormalities, weight of embryos and oxidative stress markers (TBARS, NPSH, ROS and CAT) were analyzed. RESULTS: CUR-NC (P80, PEG, EUD and CS) treatments caused antiangiogenic and non-teratogenic effects in chick embryo model. Still, CUR-NC (P80), CUR-NC (PEG), CUR-NC (EUD) and CUR-NC (CS) did not alter markers of oxidative stress (TBARS, NPSH, CAT) studied. Only CUR-NC (EUD) caused increase in ROS levels. CONCLUSION: Wherefore, these findings of present study represent a advance in research of drug/nutraceutical delivery systems.

Anxiety-like behavior and neuroendocrine changes in offspring resulting from gestational post-traumatic stress disorder.

Exposure to stressful environmental events during the perinatal period can increase vulnerability to psychopathologies that cause neuroendocrine changes associated with deficits in emotional behavior that can appear early in life. Post-traumatic stress disorder (PTSD) is a frequent, chronic, and disabling disorder that negatively impacts the emotional, social, and cognitive behaviors of affected individuals. Thus, we induced PTSD in pregnant rats by applying inescapable footshocks and then investigated the behavioral parameters similar to anxiety in offspring at prepubertal age, in addition to the plasma levels of maternal and offspring corticosterone and expression of glucocorticoid receptors (GR) in the offspring's hippocampus. With the dams, maternal behavior, open field, and object recognition tests were performed. With the male and female offspring, we performed the following: quantification of ultrasonic vocalizations, elevated plus-maze test, evaluation of exploratory activity in the open field, and hole board test, as well as plasma corticosterone measurements and Western blotting for GR. Our results showed that gestational PTSD affected maternal behavior, led to anxiety-like symptoms, increased corticosterone levels, and increased GR expression in the offspring's hippocampus. Therefore, our data can contribute to the understanding of the onset of early (childhood and juvenile/pre-pubertal phases) anxiety owing to exposure to a traumatic event during the gestation period.

Curcumin-loaded poly(ϵ-caprolactone) lipid-core nanocapsules: Evaluation of fetal and maternal toxicity.

This study was designed to examine fetal and maternal toxicity of curcumin (CURC) loaded lipid-core nanocapsules (LNC) prepared with poly(ϵ-caprolactone) as a polymer, administered during the organogenesis period. Free CURC and CURC loaded-LNC (C-LNC) (2 mg/kg), blank LNC (B-LNC) and saline (CONTROL) were administered per oral route from the 7° to 13° gestational day (GD). Dams were evaluated daily for body weight gain, clinical signs, water and food intake. On 20° GD, dams were euthanized, organs were weighed and blood was collected for biochemical determinations. Fetal biometrics and external morphological anomalies were assessed. Also, were performed histopathological analysis of placenta and measurement of cytokines levels in placental and fetal liver tissues. All groups did not cause changes in dams during the pregnancy. Furthermore, treatments did not cause external morphological changes and delayed fetal development. Still, for histopathological analysis of placental tissue, treatments did not cause alterations in evaluated parameters. For cytokines levels, CURC and C-LNC caused a decrease in placental levels of TNF-α. Therefore, we have demonstrated that C-LNC did not cause toxicological effects (mother and fetus), in the same manner as pattern bioactive compound, proving to be a promising nutraceutical delivery system for maternal supplementation with CURC.

Metabolic syndrome accentuates post-traumatic stress disorder-like symptoms and glial activation.

The relationship between individuals with post-traumatic stress disorder (PTSD) and the development of metabolic syndrome (MS) is well understood, but the relationship between individuals with preexisting MS and the development of PTSD is not yet known. Therefore, we evaluated the course of PTSD development in preexisting MS rats and we quantified the glial fibrillary acidic protein (GFAP) and ionized the calcium binding adaptor molecule 1 (Iba-1) in the cortex and hippocampus of the experimental animals. Male Wistar rats were divided into two groups: control or 10 % fructose for 5 weeks. After 5 weeks of MS induction, a group of animals was used to characterize MS. In another group, after 5 weeks of MS induction, animals were exposed to or not exposed to inescapable footshocks, followed by social isolation. After 14 days of a retention interval, the animals were re-exposed to the inescapable footshocks box, and the freezing time was evaluated. Over the following days, the animals were tested using the open field, social interaction and forced swimming tests, respectively. In another group of animals, after induction of MS and PTSD as previously described, elevated plus maze and object recognition tests were performed. Our results demonstrate that fructose solution for 5 weeks was able to induce MS, and animals with MS had more pronounced PTSD-like symptoms and a greater increase in GFAP and Iba-1 in the hippocampus and prefrontal cortex. In conclusion, MS accentuated PTSD-like symptoms that may be related to increased glial activation. This study helps reveal factors that may predispose individuals to the development of PTSD, such as metabolic disorders.

Maternal protein malnutrition prolongs sickness behavior in male offspring.

Female rats were fed a normal or hypoproteic diet during the phases of gestation and lactation. The male offspring of these rats were grown to adulthood and used to study the effects of maternal protein malnutrition on progeny. The adult male rats were pretreated with either saline or LPS and subjected to behavioral tests 2 and 6 h after administration. Tumor necrosis factor (TNF-α), corticosterone and body temperature were the parameters used for assessment. Two hours after LPS administration, sickness behavior was developed in all the animals, regardless of maternal protein malnutrition. After 6 h of LPS administration, sickness behavior was more pronounced in the rats that had been subjected to maternal protein malnutrition. Only the rats with maternal protein malnutrition expressed an increase in the plasma levels of TNF-α and corticosterone. Maternal protein malnutrition prolongs sickness behaviors in offspring.

Iodine­131 metabolic radiotherapy leads to cell death and genomic alterations through NIS overexpression on cholangiocarcinoma.

Cholangiocarcinoma (CC) is an aggressive liver tumor with limited therapeutic options. Natrium­iodide symporter (NIS) mediates the uptake of iodine by the thyroid, representing a key component in metabolic radiotherapy using iodine­131 (131I) for the treatment of thyroid cancer. NIS expression is increased in CC, providing the opportunity for a novel therapeutic approach for this type of tumor. Thus, in this study, we aimed to evaluate therapeutic efficacy of 131I in two human CC cell lines. Uptake experiments analyzed the 131I uptake profiles of the tumor cell lines under study. The cells were irradiated with various doses of 131I to evaluate and characterize the effects of metabolic radiotherapy. NIS protein expression was assessed by immunofluorescence methods. Cell survival was evaluated by clonogenic assay and flow cytometry was used to assess cell viability, and the type of death and alterations in the cell cycle. The genomic and epigenetic characterization of both CC cells was performed before and after irradiation. NIS gene expression was evaluated in the CC cells by RT­qPCR. The results revealed that CC cells had a higher expression of NIS. 131I induced a decrease in cell survival in a dose­dependent manner. With the increasing irradiation dose, a decrease in cell viability was observed, with a consequent increase in cell death by initial apoptosis. Karyotype and array comparative genomic hybridization (aCGH) analyses revealed that both CC cell lines were near­triploid with several numerical and structural chromosomal rearrangements. NIS gene expression was increased in the TFK­1 and HuCCT1 cells in a time­dependent manner. On the whole, the findings of this study demonstrate that the presence of NIS in cholangiocarcinoma cell lines is crucial for the decreased cell viability and survival observed following the exposure of cholangiocarcinoma cells to 131I.