BACKGROUND: Programmed cell death-1 (PD-1) and PD ligand-1 (PD-L1) expression predict the biological behaviour, aggressiveness, and response to immune checkpoint inhibitors in different cancers. We reviewed the published data on PD-L1 expression in pituitary tumours from the perspective of its biological role and prognostic usefulness. SUMMARY: A literature review focused on PD-L1 expression in pituitary tumours was performed. Six immunohistochemistry-based studies which assessed PD-L1 positivity in pituitary tumours were included, encompassing 704 patients. The cohort consisted of 384 (54.5%) nonfunctioning tumours and 320 (43.5%) functioning pituitary tumours. PD-L1 expression was positive in 248 cases (35.2%). PD-L1 positivity rate was higher in functioning than in nonfunctioning tumours (46.3% vs. 26.0%; p < 0.001) but also higher in growth hormone-secreting tumours (56.7%) and prolactinomas (53.6%) than in thyrotroph (33.3%) or corticotroph tumours (20.6%). While proliferative pituitary tumours showed higher rate of PD-L1 positivity than non-proliferative tumours (p < 0.001), no association with invasion or recurrence was found. KEY MESSAGES: PD-L1 is expressed in a substantial number of pituitary tumours, predominantly in the functioning ones. PD-L1 positivity rates were significantly higher in proliferative pituitary tumours in comparison to non-proliferative tumours, but no differences were found concerning invasive or recurrent pituitary tumours. More studies following homogeneous and standardised methodologies are needed to fully elucidate the role and usefulness of PD-L1 expression in pituitary tumours.
Introduction: Management of pediatric cancer patients involves invasive procedures such as punctures, injections, catheter placements, and chemotherapy which can generate fatigue, nausea, vomiting, anxiety, and pain. Virtual Reality (VR) is a nonpharmacological intervention classified as a cognitive-behavioral method to relieve symptoms. Methods: We designed a crossover protocol and included 20 patients between 9 and 12 years old; ten were male. All patients had acute lymphoblastic leukemia diagnosis and were treatedwith St. Jude's XV protocol in the maintenance phase. Pain and anxiety were measured with validated scales in the pediatric population. Results: Although we used a small group of patients, we found statistical difference in the reduction of anxiety and perception of time. Discussion: These results open a window to non-pharmacological treatments and show a strategy to improve quality of life in children inside the hospital.
BACKGROUND: Although motorcycle helmets can save lives in case of a crash, no helmet use data are available for many countries. When data is available, it is often only analysed as a global average, preventing targeted road safety education and legislative action. In this study, we conducted a detailed analysis of motorcycle helmet use in the capital of Madagascar. METHODS: Using a cross-sectional observational field survey framework, we observed 17 230 individual motorcycles. We systematically recorded motorcycle riders' helmet use, position on the motorcycle, rider numbers and gender. RESULTS: We found a general helmet use of 76.1%. Observed drivers had a significantly higher helmet use (84.6%) than passengers (47.7%), and subsequently helmet use per motorcycle decreased significantly when the number of riders per motorcycle increased. Female drivers had significantly higher helmet use than male drivers, and female passengers had significantly higher helmet use than male passengers. That is, on the same position of the motorcycle, female riders behaved safer than male riders. However, since female riders were more often passengers than drivers, their average helmet use was lower than that of male riders overall. Contrary to findings from other countries, motorcycle helmet use did not differ significantly throughout the day but was relatively constant. CONCLUSION: Our results show the potential for injury and fatality prevention in Madagascar through increased passenger helmet use. This increase would also proportionally benefit female riders more than male riders. Findings regarding road safety legislation's applied impact, education, enforcement and future research needs are discussed.
BACKGROUND AND PURPOSE: Undiagnosed atrial fibrillation (AF) is a major risk factor for stroke that can go unnoticed in individuals with embolic stroke of undetermined source (ESUS) or cryptogenic stroke (CS). Early detection is critical for stroke prognosis and secondary prevention. This study aimed to determine if blood biomarkers of myocardial stress can accurately predict AF in patients with ESUS/CS, which would allow the identification of those who would benefit from closer monitoring. METHODS: In February 2023 we performed a systematic date-unrestricted search of three databases for studies on patients with ESUS/CS who were subsequently diagnosed with AF. We examined the relationships between AF and serum myocardial stress markers such as brain natriuretic peptide (BNP), N-terminal-pro-BNP (NT-proBNP), midregional proatrial natriuretic peptide, and troponin. RESULTS: Among the 1,527 studies reviewed, 23 eligible studies involving 6,212 participants, including 864 with AF, were analyzed. A meta-analysis of 9 studies indicated that they demonstrated a clear association between higher NT-proBNP levels and an increased risk of AF, with adjusted and raw data indicating 3.06- and 9.03-fold higher AF risks, respectively. Lower NT-proBNP levels had a pooled negative predictive value of 91.7%, indicating the potential to rule out AF with an 8% false-negative rate. CONCLUSIONS: Further research is required to fully determine the potential of biomarkers for AF detection after stroke, as results from previous studies lack homogeneity. However, lower NT-proBNP levels have potential in ruling out AF in patients with ESUS/CS. Combining them with other relevant biomarkers may enhance the precision of identifying patients who will not benefit from extended monitoring, which would optimize resource allocation and patient care.
Objetivo Los Servicios de Salud en Chile tienen una demanda insatisfecha en ortodoncia y muchas de las interconsultas no son pertinentes. Buscando una solución, el Servicio de Salud Metropolitano Norte (SSMN) implementó la "Guía de Referencia Clínica Ortodoncia (GRCO) para Servicios Públicos de Salud". El objetivo de este estudio fue evaluar si existe asociación entre utilizar GRCO y pertinencia en derivaciones a Ortodoncia realizadas por odontólogos de Atención Primaria. Materiales y Métodos Se realizó un estudio observacional analítico en 167 pacientes derivados por odontólogos que utilizaron la GRCO y 167 pacientes derivados por odontólogos que no la utilizaron. Una especialista en ortodoncia evaluó pertinencia en la derivación. Los datos se analizaron mediante la prueba de chi-cuadrado, y la prueba t-test. Resultados De los odontólogos que usaron la guía solo un 3% de sus derivaciones fueron no pertinentes, mientras que aquellos que no la usaron, tuvieron un 54% de derivaciones no pertinentes (p <0,001). Odontólogos que no usan la GRCO presentan 38 veces más probabilidad de realizar una derivación no pertinente. (OR 38,8; IC 14,9 - 125,9). Conclusión El uso de Guía de Referencia Clínica a Ortodoncia se asocia fuertemente con la pertinencia en la derivación de pacientes a la especialidad ortodoncia.
Objective. Health Services in Chile have an unsatisfied demand in orthodontics and the largest waiting list for dental specialties, with many of the referrals being irrelevant. Seeking a solution, the North Metropolitan Health Service (SSMN) implemented the "Orthodontic Clinical Referral Guideline (GRCO) for Public Health Services", to define the appropriateness of referrals. The objective of this study was to assess whether there is an association between the GRCO and the appropriateness of orthodontic referrals made by Primary Health Care dentists of the SSMN. Materials and methods. An analytical observational study was carried out in 167 patients referred by dentists who used the GRCO and 167 patients referred by dentists who did not use it. A calibrated orthodontic specialist assessed the relevance of the referral. The data was analyzed using the chi-square test, and the t-test. Results. Only 3% of the referrals made by dentists who used the GRCO were inappropriate, compared to 54% of those who did not use it. Dentists who do not use the GRCO are 38 times more likely to make an inappropriate referral than those who adhere to the GRCO (OR 38.8; CI 14.9 - 125.9) Conclusion. The use of the Orthodontic Clinical Referral Guideline is strongly associated with appropriateness in referring patients to the orthodontic specialty.
When an initial marketing authorization of a pharmaceutical product is granted, a substantial number of chemistry, manufacturing and control (CMC) post approval changes (PACs) have to be managed by the manufacturers. Despite efforts undertaken over the years by multiple regulatory jurisdictions, there is still heterogeneity in terms of regulatory requirements and timelines across national regulatory authorities (NRAs). This creates complexity in managing global CMC PACs, putting the supply of medical products at risk. Regulators have developed regulatory mechanisms which aim at accelerating the reviews and approvals of PACs by NRAs. The World Health Organization (WHO) is supporting the concept of 'reliance' amongst NRAs which are encouraged to rely on the assessment completed by a â³high-performing authorityâ³. The objective is to accelerate the overall process for PACs, ultimately fostering more equitable and timely access of medical products to populations who need them. With the support of Health Canada, WHO, Pan American Health Organization, and the Paul-Ehrlich-Institut, Sanofi has launched a pilot using the principles of reliance for a CMC PAC for a vaccine, with 21 NRAs who accepted to participate in the pilot. The objective of this pilot was to apply these principles to reduce the approval timeline to a maximum of 6 months, in all countries after an initial approval is granted by a reference authority. We discussed the opportunities and challenges of implementing reliance principles for CMC PACs. We also described the pilot experience, by sharing initial lessons learned from the Step 1 of this pilot, which consist of engaging the reference authority and the NRAs.
CONTEXT: Studies that analyze the temporal trend and spatial clustering of medical education indicators are scarce, especially in developing countries such as Brazil. This analysis is essential to subsidize more equitable policies for the medical workforce in the states and regions of Brazil. Thus, this study aimed to analyze the temporal trend and identify spatial clusters of medical education indicators in Brazil disaggregated by public and private education, states, and regions. METHODS: A time-series ecological study was conducted using data from the Higher Education Census of the Ministry of Education from 2010 to 2021. The study analyzed vacancy density indicators of active and former students/100,000 population, disaggregated by public and private education, 27 states, and 5 regions in Brazil. Prais-Winsten regression was used for trend analyses of indicators. Hot Spot Analysis (Getis-Ord Gi*) was used to identify spatial clusters of indicators. RESULTS: The number of medical schools increased by 102.2% between 2010 and 2021. A total of 366 medical schools offered 54,870 vacancies at the end of 2021. Vacancy density and active and former students increased significantly in the period, but this increase was greater in private institutions. Most states and regions showed an increasing trend in the indicators, with higher increase percentages in private than in public schools. Hot spot spaces changed over time, concentrated in the southeast, center-west, and north at the end of 2021. Medical education remains uneven in Brazil, with a low provision in regions with low socioeconomic development, academic structure, and health services, represented by regions in the north and northeast. CONCLUSIONS: There is a growing trend in medical education indicators in Brazil, especially in the private sector. Spatial clusters were found predominantly in the southeast, center-west, and north. These results indicate the need for more equitable medical education planning between the regions.
Education, Medical , Humans , Time Factors , Brazil/epidemiology , Schools, Medical , Cluster Analysis
As the World slowly emerged from the then-ongoing pandemic, War broke out in Europe with the invasion of Ukraine by Russia. The enduring military conflict in Ukraine has had sweeping consequences at the human, social, economic, and environmental levels, not only for the nations involved but across Europe and globally. Damaged infrastructures, severe disruption of economic activity, and forced migration have led to negative impacts on sustainability. The COVID-19 pandemic has added another layer of complexity to this already challenging situation, as the virus has further disrupted economic activity and strained healthcare systems. Herein, we examine how the intersection of war and COVID-19 affect the United Nations' 2030 Agenda for Sustainable Development. How these intersecting challenges have impacted efforts to build a more sustainable future, and how these impacts have a global reach are also assessed. The broader implications of this case for understanding the linkages between conflict, pandemics, and sustainability more generally are also considered, relating these with the United Nations' Sustainable Development Goals (SDG) Agenda for 2030.
COVID-19 , Military Personnel , Humans , Ukraine/epidemiology , Pandemics , COVID-19/epidemiology , Europe
The aim of this study was to analyze the scenario of medical residency programs (MRPs) in the north region of Brazil as well as the contextual determinants (socioeconomic, structural, and epidemiological) influencing the number of MRPs in this region. An ecological study was conducted using MRPs data from 2022. This study used multiple data sources. MRP indicators were described based on the Brazilian state and specialty. The dependent variable was the number of MRPs. The independent variables included sociodemographic, structural, and epidemiological factors. Poisson regression was performed to analyze the association between contextual variables and the number of MRPs. The results showed that only 3.6% of the municipalities had authorized MRPs. The idleness rate in the region was 46.0%, with family and community medicine as the specialties with the greatest idleness. The total density of authorized vacancies in the MRPs was 14.0 vacancies per 100,000 inhabitants. The models showed that with each increase of one unit of the vulnerability index (Socioeconomic Index in the Geographic Context for Health Studies-GeoSES), the number of MRPs increased, ranging from 8122 (p value < 0.001) to 11,138 (p value < 0.001). With each increase in undergraduate degrees in medicine, the number of MRPs increased by 0.945 (p value < 0.001). With each increase of 1 physician per 1000 population, the number of MRPs increased from 0.537 (p value < 0.001) to 0.845 (p value < 0.001). With each increase of one unit in general hospitals, specialized hospitals, teaching hospitals, and primary healthcare units, the number of MRPs increased by 0.176 (p value < 0.001), 0.168 (p value < 0.001), 0.022 (p value < 0.001) and 0.032 (p value < 0.001), respectively. Finally, with each increase of one death per 100,000 inhabitants, the overall mortality rate increased, ranging from 0.006 (p value < 0.001) to 0.022 (p value < 0.001). The study showed a low supply of MRPs in the northern region, a high rate of idleness, and important socioeconomic, structural, and epidemiological determinants of the number of MRPs.
PURPOSE: A clinicopathological classification has been designed to predict recurrence/progression in patients with pituitary adenomas (PAs). We aimed to study its usefulness in predicting PAs that will have a challenging disease course and may require more often complex multimodal and multiple therapeutic approaches. METHODS: Retrospective analysis of 129 patients with PAs operated in our institution between 2001 and 2020 (84 non-clinically functioning PAs, 32 acromegaly, 9 Cushing's disease, 2 prolactinomas and 2 thyrotropinomas). Grading was based on invasion and proliferation: 1a (non-invasive, non-proliferative; n = 59), 1b (non-invasive, proliferative; n = 17), 2a (invasive, non-proliferative; n = 38), and 2b (invasive, proliferative; n = 15). RESULTS: Of the 129 patients, 68 (52.7%) were females, and the mean age at diagnosis was 53.7 ± 15.4 years. The mean follow-up duration was 93.1 ± 61.8 months. Grade 2b PAs when compared to other grades (2b-2a-1b-1a) had significantly higher rates of persistent tumor remnant within 1-year after operation (93-78-18-30%; p < 0.001), active disease at last follow-up (40-27-12-10%; p = 0.004), re-operation (27-16-0-5%; p = 0.023), irradiation (53-38-12-7%; p < 0.001), multimodal treatment (67-49-18-25%; p = 0.003), multiple treatment (33-27-6-9%; p = 0.017). Patients with grade 2b PAs also required a higher mean number of treatments (2.6-2.1-1.2-1.4; p < 0.001). CONCLUSIONS: This clinicopathological classification appears to be a useful grading system to identify PAs that may be more refractory and more often require complex multimodal and multiple therapeutic approaches. Invasive PAs, especially grade 2b tumors, may be more likely to need complex treatment approach, including radiotherapy, and may display higher rates of active disease at last follow-up, despite receiving higher number of treatments.
Adenoma , Pituitary Neoplasms , Female , Humans , Adult , Middle Aged , Aged , Male , Pituitary Neoplasms/pathology , Retrospective Studies , Portugal , Pituitary Gland/pathology , Adenoma/pathology
In recent years, lycopene has been highlighted due to its antioxidant and anti-inflammatory properties, associated with a beneficial effect on human health. The aim of this study was to advance the studies of antioxidant and anti-inflammatory mechanisms on human keratinocytes cells (HaCaT) of a self-emulsifying drug delivery system (SEDDS) loaded with lycopene purified from red guava (nanoLPG). The characteristics of nanoLPG were a hydrodynamic diameter of 205 nm, a polydispersity index of 0.21 and a zeta potential of -20.57, providing physical stability for the nanosystem. NanoLPG demonstrated antioxidant capacity, as shown using the ORAC methodology, and prevented DNA degradation (DNA agarose). Proinflammatory activity was evaluated by quantifying the cytokines TNF-α, IL-6 and IL-8, with only IL-8 showing a significant increase (p < 0.0001). NanoLPG showed greater inhibition of the tyrosinase and elastase enzymes, involved in the skin aging process, compared to purified lycopene (LPG). In vitro treatment for 24 h with 5.0 µg/mL of nanoLPG did not affect the viability of HaCaT cells. The ultrastructure of HaCaT cells demonstrated the maintenance of morphology. This contrasts with endoplasmic reticulum stresses and autophagic vacuoles when treated with LPG after stimulation or not with LPS. Therefore, the use of lycopene in a nanoemulsion may be beneficial in strategies and products associated with skin health.
Antioxidants , Interleukin-8 , Humans , Lycopene , Antioxidants/pharmacology , Drug Delivery Systems/methods , Anti-Inflammatory Agents/pharmacology , DNA
Atrial fibrillation (AF) is a cardiac arrhythmia caused by electrophysiological anomalies in the atrial tissue, tissue degradation, structural abnormalities, and comorbidities. A direct relationship exists between AF and altered mitochondrial activity resulting from membrane potential loss, contractile dysfunction, or decreased ATP levels. This review aimed to elucidate the role of mitochondrial oxidative mechanisms in AF pathophysiology, the impact of mitochondrial oxidative stress on AF initiation and perpetuation, and current therapies. This review followed the Preferred Reporting Items for Systematic Reviews and the Meta-Analysis Extension for Scoping Reviews. PubMed, Excerpta Medica Database, and Scopus were explored until June 2023 using "MESH terms". Bibliographic references to relevant papers were also included. Oxidative stress is an imbalance that causes cellular damage from excessive oxidation, resulting in conditions such as AF. An imbalance in reactive oxygen species production and elimination can cause mitochondrial damage, cellular apoptosis, and cardiovascular diseases. Oxidative stress and inflammation are intrinsically linked, and inflammatory pathways are highly correlated with the occurrence of AF. AF is an intricate cardiac condition that requires innovative therapeutic approaches. The involvement of mitochondrial oxidative stress in the pathophysiology of AF introduces novel strategies for clinical treatment.
Atrial Fibrillation , Heart Diseases , Mitochondrial Diseases , Humans , Atrial Fibrillation/drug therapy , Cardiac Conduction System Disease , Oxidative Stress
This work reports the application of Mn-doped Co3O4 oxides in the electrocatalytic oxygen evolution reaction (OER). The materials were characterized by structural, morphological, and electrochemical techniques. The oxides with higher Co : Mn molar ratio presented a lower electron transfer resistance, and consequently the most promising OER activities. Pure Co3O4 shows an overpotential at j = 10 mA cm-2 of 761, 490, and 240 mV, at pH 1, 7, and 14, respectively, and a high TOF of 1.01 × 10-1 s-1 at pH 14. Tafel slopes around 120 mV dec-1 at acidic pH and around 60 mV dec-1 at alkaline pH indicate different OER mechanisms. High stability for Co3O4 was achieved for up to 15 h in all pHs, and no change in the structure and morphology after the electrocatalysis was observed. The reported excellent OER activity of the Mn-Co oxides in a wide pH range is important to broaden the practical applicability in different electrolyte solutions.
Metal pollution in aquatic ecosystems translates into increased concentrations of sediment-bound metals, representing a risk for benthic species. This risk might be enhanced in soft and moderately hard waters, world widely distributed, due to the protective role of hardness against metal toxicity. As lead (Pb) and nickel (Ni) are amongst the more abundant metals in aquatic systems, and since their combined effects to benthic species have been overlooked, in this study we aimed to investigate the life-cycle toxicity of Pb and Ni (using spiked sediment) to the benthic species Chironomus riparius, considering both single and mixture exposures, in moderately hard water. Environmentally relevant concentrations of each metal were used (25 and 75 mg kg-1, based on a scenario of pollution by runoff waters from burnt forests), following a full factorial design. Effects of the mixture with the highest metal concentrations (Pb 75 mg kg-1 dw + Ni 75 mg kg-1 dw) were also assessed in the second generation. In the first generation, exposure to Pb increased emergence and the weight of males, and decreased time to emergence of both males and females. Conversely, exposure to Ni delayed female emergence and decreased the weight of imagoes. Summarizing, Pb affected more endpoints but showed an apparent positive effect, whereas Ni affected less endpoints but exhibited adverse effects. Reproduction was not affected by these metals. In the second generation, the mixture Pb 75 mg kg-1 + Ni 75 mg kg-1 dw delayed emergence and reduced the emerged female fraction and their weight. These results highlight that Pb and Ni can alter the structure of C. riparius populations at environmentally relevant concentrations, which signals potential repercussions in the dynamics and functioning of freshwater ecosystems under these contamination scenarios. The findings of the present study are relevant not only for metal-polluted environments, in general, but also for fire-affected ecosystems.
Chironomidae , Water Pollutants, Chemical , Animals , Female , Nickel/toxicity , Geologic Sediments/chemistry , Lead/toxicity , Water Pollutants, Chemical/toxicity , Ecosystem
While most cases of differentiated thyroid carcinoma (DTC) are associated with a good prognosis, a significant number progress to advanced disease exhibiting aggressive clinical characteristics and often becoming refractory to radioactive iodine (RAI) treatment, the current gold-standard therapeutic option for metastatic disease. RAI-refractoriness is caused by defective functional expression of the sodium-iodide symporter (NIS), which is responsible for the active transport of iodide across the plasma membrane (PM) into thyroid follicles. NIS deficiency in these tumors often reflects a transcriptional impairment, but also its defective targeting and retention at the cells' PM. Using proteomics, we previously characterized an intracellular signaling pathway derived from SRC kinase that acts through the small GTPase RAC1 to recruit and bind the actin-anchoring adaptor EZRIN to NIS, regulating its retention at the PM of both non-transformed and cancer thyroid cells. Here, we describe how by reanalyzing the proteomics data, we identified cell-cell adhesion as the molecular event upstream the pathway involved in the anchoring and retention at the PM. We show that by interacting with NIS at the PM, adherens junction (AJ)-associated P120-catenin recruits and is phosphorylated by SRC, allowing it to recruit RAC1 to the complex. This enables SRC-phosphorylated VAV2 exchange factor to activate RAC1 GTPase, inducing NIS retention at the PM, thus increasing its abundance and function at the surface of thyroid cells. Our findings indicate that the loss of epithelial cell-cell adhesion may contribute to RAI refractoriness, indicating that in addition to stimulating NIS expression, successful resensitization therapies might require the employment of agents that improve cell-cell adhesion and NIS PM retention in refractory TC cells.
BACKGROUND: RNA is a critical analyte for unambiguous detection of actionable mutations used to guide treatment decisions in oncology. Currently available methods for gene fusion detection include molecular or antibody-based assays, which suffer from either being limited to single-gene targeting, lack of sensitivity, or long turnaround time. The sensitivity and predictive value of next generation sequencing DNA-based assays to detect fusions by sequencing intronic regions is variable, due to the extensive size of introns. The required depth of sequencing and input nucleic acid required can be prohibitive; in addition it is not certain that predicted gene fusions are actually expressed. RESULTS: Herein we describe a method based on pyrophosphorolysis to include detection of gene fusions from RNA, with identical assay steps and conditions to detect somatic mutations in DNA [1], permitting concurrent assessment of DNA and RNA in a single instrument run. CONCLUSION: The limit of detection was under 6 molecules/ 6 µL target volume. The workflow and instrumentation required are akin to PCR assays, and the entire assay from extracted nucleic acid to sample analysis can be completed within a single day.
Gene Fusion , RNA , High-Throughput Nucleotide Sequencing/methods , Mutation , RNA/genetics , Sequence Analysis, RNA
The microenvironment of pituitary adenomas (PAs) includes a range of non-tumoral cells, such as immune and stromal cells, as well as cell signaling molecules such as cytokines, chemokines and growth factors, which surround pituitary tumor cells and may modulate tumor initiation, progression, invasion, angiogenesis and other tumorigenic processes. The microenvironment of PAs has been actively investigated over the last years, with several immune and stromal cell populations, as well as different cytokines, chemokines and growth factors being recently characterized in PAs. Moreover, key microenvironment-related genes as well as immune-related molecules and pathways have been investigated, with immune check point regulators emerging as promising targets for immunotherapy. Understanding the microenvironment of PAs will contribute to a deeper knowledge of the complex biology of PAs, as well as will provide developments in terms of diagnosis, clinical management and ultimately treatment of patients with aggressive and/or refractory PAs.
Adenoma , Pituitary Neoplasms , Adenoma/metabolism , Cell Transformation, Neoplastic , Chemokines , Humans , Immunotherapy , Pituitary Neoplasms/metabolism , Tumor Microenvironment
Fabry Disease (FD) is a rare X-linked recessive disease caused by mutations in the GLA gene that lead to a decrease or lack of activity of the enzyme alpha galactosyl A. This lysosomal storage disorder results in progressive damage and dysfunction of several organs and, depending on the type of mutation and gender of the patient, and it may have different manifestations. As FD is a multisystem disease with a progressive character and varying severity, the diagnosis can be challenging, especially when it comes to non-classical forms. As this is a hereditary disease, its diagnosis impacts not only the patient but also his family, making an accurate and timely diagnosis even more important. We present the case of a 59-years-old man diagnosed with non-classical FD, with previous neurological and psychiatric complaints, who was admitted to the Emergency Department (ED) with a generalized tonic-clonic seizure that required orotracheal intubation for airway protection and transferred to an Intensive Care Unit (ICU).
The Sodium/Iodide Symporter (NIS) is responsible for the active transport of iodide into thyroid follicular cells. Differentiated thyroid carcinomas (DTCs) usually preserve the functional expression of NIS, allowing the use of radioactive iodine (RAI) as the treatment of choice for metastatic disease. However, a significant proportion of patients with advanced forms of TC become refractory to RAI therapy and no effective therapeutic alternatives are available. Impaired iodide uptake is mainly caused by the defective functional expression of NIS, and this has been associated with several pathways linked to malignant transformation. MAPK signaling has emerged as one of the main pathways implicated in thyroid tumorigenesis, and its overactivation has been associated with the downregulation of NIS expression. Thus, several strategies have been developed to target the MAPK pathway attempting to increase iodide uptake in refractory DTC. However, MAPK inhibitors have had only partial success in restoring NIS expression and, in most cases, it remained insufficient to allow effective treatment with RAI. In a previous work, we have shown that the activity of the small GTPase RAC1 has a positive impact on TSH-induced NIS expression and iodide uptake in thyroid cells. RAC1 is a downstream effector of NRAS, but not of BRAF. Therefore, we hypothesized that the positive regulation induced by RAC1 on NIS could be a relevant signaling cue in the mechanism underlying the differential response to MEK inhibitors, observed between NRAS- and BRAF-mutant tumors. In the present study, we found that the recovery of NIS expression induced through MAPK pathway inhibition can be enhanced by potentiating RAC1 activity in thyroid cell systems. The negative impact on NIS expression induced by the MAPK-activating alterations, NRAS Q61R and BRAF V600E, was partially reversed by the presence of the MEK 1/2 inhibitors AZD6244 and CH5126766. Notably, the inhibition of RAC1 signaling partially blocked the positive impact of MEK inhibition on NIS expression in NRAS Q61R cells. Conversely, the presence of active RAC1 considerably improved the rescue of NIS expression in BRAF V600E thyroid cells treated with MEK inhibitors. Overall, our data support an important role for RAC1 signaling in enhancing MAPK inhibition in the context of RAI therapy in DTC, opening new opportunities for therapeutic intervention.
The functional expression of the sodium-iodide symporter (NIS) at the membrane of differentiated thyroid cancer (DTC) cells is the cornerstone for the use of radioiodine (RAI) therapy in these malignancies. However, NIS gene expression is frequently downregulated in malignant thyroid tissue, and 30% to 50% of metastatic DTCs become refractory to RAI treatment, which dramatically decreases patient survival. Several strategies have been attempted to increase the NIS mRNA levels in refractory DTC cells, so as to re-sensitize refractory tumors to RAI. However, there are many RAI-refractory DTCs in which the NIS mRNA and protein levels are relatively abundant but only reduced levels of iodide uptake are detected, suggesting a posttranslational failure in the delivery of NIS to the plasma membrane (PM), or an impaired residency at the PM. Because little is known about the molecules and pathways regulating NIS delivery to, and residency at, the PM of thyroid cells, we here employed an intact-cell labeling/immunoprecipitation methodology to selectively purify NIS-containing macromolecular complexes from the PM. Using mass spectrometry, we characterized and compared the composition of NIS PM complexes to that of NIS complexes isolated from whole cell (WC) lysates. Applying gene ontology analysis to the obtained MS data, we found that while both the PM-NIS and WC-NIS datasets had in common a considerable number of proteins involved in vesicle transport and protein trafficking, the NIS PM complexes were particularly enriched in proteins associated with the regulation of the actin cytoskeleton. Through a systematic validation of the detected interactions by co-immunoprecipitation and Western blot, followed by the biochemical and functional characterization of the contribution of each interactor to NIS PM residency and iodide uptake, we were able to identify a pathway by which the PM localization and function of NIS depends on its binding to SRC kinase, which leads to the recruitment and activation of the small GTPase RAC1. RAC1 signals through PAK1 and PIP5K to promote ARP2/3-mediated actin polymerization, and the recruitment and binding of the actin anchoring protein EZRIN to NIS, promoting its residency and function at the PM of normal and TC cells. Besides providing novel insights into the regulation of NIS localization and function at the PM of TC cells, our results open new venues for therapeutic intervention in TC, namely the possibility of modulating abnormal SRC signaling in refractory TC from a proliferative/invasive effect to the re-sensitization of these tumors to RAI therapy by inducing NIS retention at the PM.
