Impact of treatment adherence and inhalation technique on asthma outcomes of pediatric patients: a longitudinal study.

Introduction: We aimed to evaluate the longitudinal relationships, both at between- and within-person levels, that adherence to inhaled corticosteroid-based maintenance treatment and inhalation technique present with symptom control, exacerbations, and health-related quality of life (HRQoL) in children and adolescents with asthma. Methods: Participants (6-14 years old) from the ARCA (Asthma Research in Children and Adolescents) cohort-a prospective, multicenter, observational study (NCT04480242)-were followed for a period from 6 months to 5 years via computer-assisted telephone interviews and a smartphone application. The Medication Intake Survey-Asthma (MIS-A) was administered to assess the implementation stage of adherence, and the Inhalation Technique Questionnaire (InTeQ) was used to assess the five key steps when using an inhaler. Symptom control was measured with the Asthma Control Questionnaire (ACQ), and HRQL was measured with the EQ-5D and the Patient-Reported Outcomes Measurement Information System-Pediatric Asthma Impact Scale (PROMIS-PAIS). Multilevel longitudinal mixed models were constructed separately with symptom control, exacerbation occurrence, EQ-5D, and PROMIS-PAIS as the dependent variables. Results: Of the 360 participants enrolled, 303 (1,203 interviews) were included in the symptom control and exacerbation analyses, 265 (732) in the EQ-5D, and 215 (617) in the PROMIS-PAIS. Around 60% of participants were male subjects, and most of them underwent maintenance treatment with inhaled corticosteroids plus long-acting ß-agonists in a fixed dose (73.3%). Within-person variability was 83.6% for asthma control, 98.6% for exacerbations, 36.4% for EQ-5D, and 49.1% for PROMIS-PAIS. At the within-person level, patients with higher adherence had better symptom control (p = 0.002) and HRQoL over time (p = 0.016). Patients with a better inhalation technique reported worse HRQoL simultaneously (p = 0.012), but they showed better HRQoL in future assessments (p = 0.012). The frequency of reliever use was associated with symptom control (p < 0.001), exacerbation occurrence (p < 0.001), and HRQoL (p = 0.042); and boys were more likely to present better symptom control and HRQoL than girls. Conclusion: Our results confirm longitudinal associations at the within-person level of the two indicators of quality use of inhalers: for adherence to maintenance treatment with symptom control and HRQoL, and for the inhalation technique with HRQoL. Although treatment adherence was shown to be excellent, a third of the participants reported a suboptimal inhalation technique, highlighting the need for actions for improving asthma management of the pediatric population.

A systematic review of nanocarriers for treatment of urologic cancers.

Nanocarriers (NCs) are a form of nanotechnology widely investigated in cancer treatment to improve the safety and efficacy of systemic therapies by increasing tumor specificity. Numerous clinical trials have explored the use of NCs in urologic cancers since the approval of the first NCs for cancer treatment over 20 years ago. The objective of this systematic review is to examine the effectiveness and safety of NCs in treating urological cancers. This paper summarizes the state of the field by investigating peer-reviewed, published results from 43 clinical trials involving the use of NCs in bladder, prostate, and kidney cancer patients with a focus on safety and efficacy data. Among the 43 trials, 16 were phase I, 20 phase II, and 4 phase I/II. No phase III trials have been reported. While both novel and classic NCs have been explored in urologic cancers, NCs already approved for the treatment of other cancers were more widely represented. Trials in prostate cancer and mixed trials involving both urologic and non-urologic cancer patients were the most commonly reported trials. Although NCs have demonstrable efficacy with adequate safety in non-urologic cancer patient populations, current clinical stage NC options appear to be less beneficial in the urologic cancer setting. For example, nab-paclitaxel and liposomal doxorubicin have proven ineffective in the treatment of urologic cancers despite successes in other cancers. However, several ongoing pre-clinical studies using targeted and locally applied improved NCs may eventually improve their utility.

A novel sunflower broomrape race with unusual virulence potentially caused by a mutation.

Introduction: The sunflower broomrape (Orobanche cumana Wallr.) gene pools of the Guadalquivir Valley and Cuenca province in Spain had predominantly race-F virulence. A new race G was observed recently in the Guadalquivir Valley potentially due to the genetic recombination of the avirulence genes of both gene pools. Methods: In this research, we have studied populations with atypical virulence from Cuenca. These populations parasitize on DEB2 sunflower line, resistant to all race-G populations evaluated. Ten populations collected in Cuenca province were evaluated with sunflower differential lines and genotyped with 67 SNP markers. Results: Although genetic recombination with individuals of the Guadalquivir Valley gene pool has been observed in most populations, recombination of avirulence genes was discarded as the cause of the new virulence because the population with the highest degree of attack on DEB2 showed no introgression from an external gene pool. Accordingly, a point mutation is proposed as the putative cause of the new virulence. Discussion: The present study provided a detailed characterization of each population, including the accurate classification of the individuals belonging to each of the classical Spanish gene pools, F1 hybrids, and those that evolved from hybridization between both gene pools. This information is essential to understand how sunflower broomrape populations are evolving in Spain, which in turn may be helpful to understand the dynamics of sunflower broomrape populations in other areas of the world and use this information to develop durable strategies for resistance breeding.

Prevalence and time trends of symptoms of allergic rhinitis and rhinoconjunctivitis in Spanish children: Global Asthma Network (GAN) study.

INTRODUCTION: The time trends of the prevalence of rhinitis, rhinoconjunctivitis and nasal allergy previously described in the ISAAC (International Study of Asthma and Allergies in Childhood) in 2002 are unknown; or if the geographical or age differences in Spain persist. OBJECTIVE: To describe the prevalence of rhinitis, rhinoconjunctivitis and nasal allergy in different Spanish geographical areas and compare them with those of the ISAAC. METHODS: Cross-sectional study of the prevalence of rhinitis, rhinoconjunctivitis and nasal allergy, carried out in 2016-2019 on 19943 adolescents aged 13-14 years and 17215 schoolchildren aged 6-7 years from six Spanish areas (Cartagena, Bilbao, Cantabria, La Coruña, Pamplona, and Salamanca), through a questionnaire based on the Global Asthma Network (GAN) protocol. RESULTS: The prevalences of recent rhinitis and rhinoconjunctivitis (last 12 months), and nasal allergy/hay fever were 35.1%, 17.6%, and 14.6% in the adolescents and 20%, 8.5%, and 8.9% in the schoolchildren, respectively, with rhinoconjunctivitis in adolescents varying from 20.9% in Bilbao to 13.4% in Cartagena; and in schoolchildren, from 9.8% in La Coruña to 6.4% in Pamplona. These prevalences of rhinoconjunctivitis and nasal allergy in adolescents were higher than those described in the ISAAC (16.3% and 13%) and similar in schoolchildren to the ISAAC (9% and 9.4%). CONCLUSIONS: There has been a stabilisation of rhinitis, rhinoconjunctivitis and nasal allergy in schoolchildren that slows the previous upward trend of ISAAC; and a slight non-significant increase in rhinoconjunctivitis and nasal allergy in adolescents. The variability found in adolescents would require local research to be better understood.

Prevalence and time trends of symptoms of allergic rhinitis and rhinoconjunctivitis in Spanish children: Global Asthma Network (GAN) study

Introduction: The time trends of the prevalence of rhinitis, rhinoconjunctivitis and nasal allergy previously described in the ISAAC (International Study of Asthma and Allergies in Childhood) in 2002 are unknown; or if the geographical or age differences in Spain persist. Objective: To describe the prevalence of rhinitis, rhinoconjunctivitis and nasal allergy in different Spanish geographical areas and compare them with those of the ISAAC. Methods: Cross-sectional study of the prevalence of rhinitis, rhinoconjunctivitis and nasal allergy, carried out in 2016-2019 on 19943 adolescents aged 13-14 years and 17215 schoolchildren aged 6-7 years from six Spanish areas (Cartagena, Bilbao, Cantabria, La Coruña, Pamplona, and Salamanca), through a questionnaire based on the Global Asthma Network (GAN) protocol. Results: The prevalences of recent rhinitis and rhinoconjunctivitis (last 12 months), and nasal allergy/hay fever were 35.1%, 17.6%, and 14.6% in the adolescents and 20%, 8.5%, and 8.9% in the schoolchildren, respectively, with rhinoconjunctivitis in adolescents varying from 20.9% in Bilbao to 13.4% in Cartagena; and in schoolchildren, from 9.8% in La Coruña to 6.4% in Pamplona. These prevalences of rhinoconjunctivitis and nasal allergy in adolescents were higher than those described in the ISAAC (16.3% and 13%) and similar in schoolchildren to the ISAAC (9% and 9.4%). Conclusions: There has been a stabilisation of rhinitis, rhinoconjunctivitis and nasal allergy in schoolchildren that slows the previous upward trend of ISAAC; and a slight non-significant increase in rhinoconjunctivitis and nasal allergy in adolescents. The variability found in adolescents would require local research to be better understood (AU)

How the Disruption of Mitochondrial Redox Signalling Contributes to Ageing.

In the past, mitochondrial reactive oxygen species (mtROS) were considered a byproduct of cellular metabolism. Due to the capacity of mtROS to cause oxidative damage, they were proposed as the main drivers of ageing and age-related diseases. Today, we know that mtROS are cellular messengers instrumental in maintaining cellular homeostasis. As cellular messengers, they are produced in specific places at specific times, and the intensity and duration of the ROS signal determine the downstream effects of mitochondrial redox signalling. We do not know yet all the processes for which mtROS are important, but we have learnt that they are essential in decisions that affect cellular differentiation, proliferation and survival. On top of causing damage due to their capacity to oxidize cellular components, mtROS contribute to the onset of degenerative diseases when redox signalling becomes dysregulated. Here, we review the best-characterized signalling pathways in which mtROS participate and those pathological processes in which they are involved. We focus on how mtROS signalling is altered during ageing and discuss whether the accumulation of damaged mitochondria without signalling capacity is a cause or a consequence of ageing.

NLRP1 inflammasome modulates senescence and senescence-associated secretory phenotype.

Senescence is a cellular aging-related process triggered by different stresses and characterized by the secretion of various inflammatory factors referred to as the senescence-associated secretory phenotype (SASP). Here, we present evidence that the inflammasome sensor, NLRP1, is a key mediator of senescence induced by irradiation both in vitro and in vivo. The NLRP1 inflammasome promotes senescence by regulating the expression of p16, p21, p53, and SASP in Gasdermin D (GSDMD)-dependent manner as these responses are reduced in conditions of NLRP1 insufficiency or GSDMD inhibition. Mechanistically, the NLRP1 inflammasome is activated downstream of the cytosolic DNA sensor cGMP-AMP (cGAMP) synthase (cGAS) in response to genomic damage. These findings provide a rationale for inhibiting the NLRP1 inflammasome-GSDMD axis to treat senescence-driven disorders.

Biological Stratification of Invasive and Advanced Urothelial Carcinoma.

Muscle-invasive urothelial carcinoma (UC) of the bladder remains a highly lethal malignancy. In this review the authors explore the underlying biology associated with the evolution from non-muscle-invasive UC to muscle-invasive and metastatic UC, with a special focus on the molecular stratification of UC and the potential of this stratification to be used for treatment selection.

Assessment of Predictive Genomic Biomarkers for Response to Cisplatin-based Neoadjuvant Chemotherapy in Bladder Cancer.

Cisplatin-based neoadjuvant chemotherapy (NAC) followed by radical cystectomy is recommended for patients with muscle-invasive bladder cancer (MIBC). It has been shown that somatic deleterious mutations in ERCC2, gain-of-function mutations in ERBB2, and alterations in ATM, RB1, and FANCC are correlated with pathological response to NAC in MIBC. The objective of this study was to validate these genomic biomarkers in pretreatment transurethral resection material from an independent retrospective cohort of 165 patients with MIBC who subsequently underwent NAC and radical surgery. Patients with ypT0/Tis/Ta/T1N0 disease after surgery were defined as responders. Somatic deleterious mutations in ERCC2 were found in nine of 68 (13%) evaluable responders and two of 95 (2%) evaluable nonresponders (p = 0.009; FDR = 0.03). No correlation was observed between response and alterations in ERBB2 or in ATM, RB1, or FANCC alone or in combination. In an exploratory analysis, no additional genomic alterations discriminated between responders and nonresponders to NAC. No further associations were identified between the aforementioned biomarkers and pathological complete response (ypT0N0) after surgery. In conclusion, we observed a positive association between deleterious mutations in ERCC2 and pathological response to NAC, but not overall survival or recurrence-free survival. Other previously reported genomic biomarkers were not validated. PATIENT SUMMARY: It is currently unknown which patients will respond to chemotherapy before definitive surgery for bladder cancer. Previous studies described several gene mutations in bladder cancer that correlated with chemotherapy response. This study confirmed that patients with bladder cancer with a mutation in the ERCC2 gene often respond to chemotherapy.

Autophagy promotes cell survival by maintaining NAD levels.

Autophagy is an essential catabolic process that promotes the clearance of surplus or damaged intracellular components. Loss of autophagy in age-related human pathologies contributes to tissue degeneration through a poorly understood mechanism. Here, we identify an evolutionarily conserved role of autophagy from yeast to humans in the preservation of nicotinamide adenine dinucleotide (NAD) levels, which are critical for cell survival. In respiring mouse fibroblasts with autophagy deficiency, loss of mitochondrial quality control was found to trigger hyperactivation of stress responses mediated by NADases of PARP and Sirtuin families. Uncontrolled depletion of the NAD(H) pool by these enzymes ultimately contributed to mitochondrial membrane depolarization and cell death. Pharmacological and genetic interventions targeting several key elements of this cascade improved the survival of autophagy-deficient yeast, mouse fibroblasts, and human neurons. Our study provides a mechanistic link between autophagy and NAD metabolism and identifies targets for interventions in human diseases associated with autophagic, lysosomal, and mitochondrial dysfunction.

Prevalencia y evolución temporal de síntomas de asma en España. Estudio Global Asthma Network (GAN) / Prevalence and temporal evolution of asthma symptoms in Spain. Global Asthma Network (GAN) study

Introducción: Se desconoce la evolución temporal de la prevalencia de asma descrita en el ISAAC (International Study of Asthma and Allergies in Childhood) en 2002 o si las diferencias geográficas o por edades se mantienen en España. Objetivo: Describir la prevalencia de los síntomas de asma en distintas áreas geográficas españolas y compararla con la de aquellos centros que participaron en el ISAAC. Métodos: Estudio transversal de prevalencia de asma, realizado en 2016-2019 a 19.943 adolescentes de 13-14 años y 17.215 escolares de 6-7 años de seis áreas geográficas españolas (Cartagena, Bilbao, Cantabria, La Coruña, Pamplona y Salamanca). Los síntomas de asma se recogieron mediante un cuestionario escrito y videocuestionario según el protocolo Global Asthma Network (GAN). Resultados: La prevalencia de sibilancias recientes (últimos 12 meses) fue del 15,3% a los 13-14 años y del 10,4% a los 6-7 años, con variaciones en los adolescentes, desde un 19% en Bilbao, hasta un 10,2% en Cartagena; y en los escolares, desde un 11,7% en Cartagena, hasta un 7% en Pamplona. Estas prevalencias fueron superiores a las del ISAAC (10,6% en adolescentes y 9,9% en los escolares). Un 21,3% de adolescentes y un 12,4% de los escolares refirieron asma alguna vez. Conclusiones: Existe una alta prevalencia de síntomas asmáticos con un incremento en los adolescentes y una estabilización en los escolares españoles con respecto al ISAAC. No se aprecian tan claramente variaciones geográficas en la prevalencia de asma, pero las áreas que tenían prevalencias elevadas mantienen cifras altas. (AU)

Introduction: The temporal evolution of the prevalence of asthma described in the International Study of Asthma and Allergies in Childhood (ISAAC) in 2002 is unknown, or if the geographical or age differences are maintained in Spain. Objective: To describe the prevalence of asthma symptoms in different Spanish geographical areas and compare it with that of those centers that participated in the ISAAC. Methods: Cross-sectional study of asthma prevalence, carried out in 2016–2019 with 19,943 adolescents aged 13–14 years and 17,215 schoolchildren aged 6–7 years from six Spanish geographical areas (Cartagena, Bilbao, Cantabria, La Coruña, Pamplona and Salamanca). Asthma symptoms were collected using a written questionnaire and video questionnaire according to the Global Asthma Network (GAN) protocol. Results: The prevalence of recent wheezing (last 12 months) was 15.3% at 13–14 years and 10.4% at 6–7 years, with variations in adolescents, from 19% in Bilbao to 10.2% in Cartagena; and in schoolchildren, from 11.7% in Cartagena to 7% in Pamplona. These prevalences were higher than those of the ISAAC (10.6% in adolescents and 9.9% in schoolchildren). About 21.3% of adolescents and 12.4% of schoolchildren reported asthma at some time. Conclusions: There is a high prevalence of asthmatic symptoms with an increase in adolescents and a stabilization in Spanish schoolchildren with respect to the ISAAC. Geographical variations in asthma prevalence are not so clearly appreciated, but areas with high prevalences maintain high numbers. (AU)

Prevalence and temporal evolution of asthma symptoms in Spain. Global Asthma Network (GAN) study.

INTRODUCTION: The temporal evolution of the prevalence of asthma described in the ISAAC (International Study of Asthma and Allergies in Childhood) in 2002 is unknown, or if the geographical or age differences are maintained in Spain. OBJECTIVE: To describe the prevalence of asthma symptoms in different Spanish geographic areas and compare it with that of those centers that participated in the ISAAC. METHODS: Cross-sectional study of asthma prevalence, carried out in 2016-2019 with 19,943 adolescents aged 13-14 years and 17,215 schoolchildren aged 6-7 years from 6 Spanish geographical areas (Cartagena, Bilbao, Cantabria, La Coruña, Pamplona and Salamanca). Asthma symptoms were collected using a written questionnaire and video questionnaire according to the Global Asthma Network (GAN) protocol. RESULTS: The prevalence of recent wheezing (last 12 months) was 15.3% at 13-14 years and 10.4% at 6-7 years, with variations in adolescents, from 19% in Bilbao to 10.2% in Cartagena; and in schoolchildren, from 11.7% in Cartagena to 7% in Pamplona. These prevalences were higher than those of the ISAAC (10.6% in adolescents and 9.9% in schoolchildren). 21.3% of adolescents and 12.4% of schoolchildren reported asthma at some time. CONCLUSIONS: There is a high prevalence of asthmatic symptoms with an increase in adolescents and a stabilization in Spanish schoolchildren with respect to the ISAAC. Geographic variations in asthma prevalence are not so clearly appreciated, but areas with high prevalences maintain high numbers.

Mitochondrial electron transport chain defects modify Parkinson's disease phenotypes in a Drosophila model.

INTRODUCTION: Mitochondrial defects have been implicated in Parkinson's disease (PD) since complex I poisons were found to cause accelerated parkinsonism in young people in the early 1980s. More evidence of mitochondrial involvement arose when many of the genes whose mutations caused inherited PD were discovered to be subcellularly localized to mitochondria or have mitochondrial functions. However, the details of how mitochondrial dysfunction might impact or cause PD remain unclear. The aim of our study was to better understand mitochondrial dysfunction in PD by evaluating mitochondrial respiratory complex mutations in a Drosophila melanogaster (fruit fly) model of PD. METHODS: We have conducted a targeted heterozygous enhancer/suppressor screen using Drosophila mutations within mitochondrial electron transport chain (ETC) genes against a null PD mutation in parkin. The interactions were assessed by climbing assays at 2-5 days as an indicator of motor function. A strong enhancer mutation in COX5A was examined further for L-dopa rescue, oxygen consumption, mitochondrial content, and reactive oxygen species. A later timepoint of 16-20 days was also investigated for both COX5A and a suppressor mutation in cyclope. Generalized Linear Models and similar statistical tests were used to verify significance of the findings. RESULTS: We have discovered that mutations in individual genes for subunits within the mitochondrial respiratory complexes have interactions with parkin, while others do not, irrespective of complex. One intriguing mutation in a complex IV subunit (cyclope) shows a suppressor rescue effect at early time points, improving the gross motor defects caused by the PD mutation, providing a strong candidate for drug discovery. Most mutations, however, show varying degrees of enhancement or slight suppression of the PD phenotypes. Thus, individual mitochondrial mutations within different oxidative phosphorylation complexes have different interactions with PD with regard to degree and direction. Upon further investigation of the strongest enhancer (COX5A), the mechanism by which these interactions occur initially does not appear to be based on defects in ATP production, but rather may be related to increased levels of reactive oxygen species. CONCLUSIONS: Our work highlights some key subunits potentially involved in mechanisms underlying PD pathogenesis, implicating ETC complexes other than complex I in PD.

Classifying Pulmonary and Urinary High-grade Neuroendocrine Carcinoma by CK7 Immunohistochemistry.

High-grade neuroendocrine carcinoma (HGNEC) is subclassified into small cell carcinoma (SmCC) and large cell neuroendocrine carcinoma (LCNEC). Although both are clinically aggressive, the SmCC and LCNEC need to have different treatment strategies, and accurate pathologic diagnosis is challenging. We studied a large retrospective cohort (186 cases) of HGNEC of bladder and lung to investigate the abundance of cytokeratin (CK) 7 expression and staining pattern in SmCC and LCNEC. Overall, the pulmonary and urinary HGNEC exhibited several different CK7 staining patterns, including negative staining (n=28), dot-like staining (n=73), partial membranous staining (n=26), and complete membranous staining (n=60). Overall, 88.9% (44/49) of pulmonary SmCC and 88.0% (44/50) of urinary SmCC showed negative or dot-like patterns for CK7, while 90.8% (59/65) of pulmonary LCNEC and 72.7% (16/22) of urinary LCNEC showed partial or complete membranous patterns for CK7 (χ 2 =105.05, P <0.0001). The distinct staining patterns were also present in those mixed SmCC and LCNEC. In addition, the specimen types or fixation did not affect CK7 staining patterns. In conclusion, CK7 has a high differential value for SmCC and LCNEC and could help guide personalized treatment for patients.

Study protocol for the St James's Hospital, Tallaght University Hospital, Trinity College Dublin Allied Researchers' (STTAR) Bioresource for COVID-19.

Background: The current coronavirus disease 2019 (COVID-19) pandemic began in Ireland with the first confirmed positive case in March 2020. In the early stages of the pandemic clinicians and researchers in two affiliated Dublin hospitals identified the need for a COVID-19 biobanking initiative to support and enhance research into the disease. Through large scale analysis of clinical, regional, and genetic characteristics of COVID-19 patients, biobanks have helped identify, and so protect, at risk patient groups The STTAR Bioresource has been created to collect and store data and linked biological samples from patients with SARS-CoV-2 infection and healthy and disease controls. Aim: The primary objective of this study is to build a biobank, to understand the clinical characteristics and natural history of COVID-19 infection with the long-term goal of research into improved disease understanding, diagnostic tests and treatments. Methods: This is a prospective dual-site cohort study across two tertiary acute university teaching hospitals. Patients are recruited from inpatient wards or outpatient clinics. Patients with confirmed COVID-19 infection as well as healthy and specific disease control groups are recruited.  Biological samples are collected and a case report form detailing demographic and medical background is entered into the bespoke secure online Dendrite database. Impact: The results of this study will be used to inform national and international strategy on health service provision and disease management related to COVID-19. In common with other biobanks, study end points  evolve over time as new research questions emerge. They currently include patient survival, occurrence of severe complications of the disease or its therapy, occurrence of persistent symptoms following recovery from the acute illness and vaccine responses.

Uroplakin II as a single marker for luminal versus basal molecular subtypes in muscle invasive urothelial carcinoma.

Bladder cancer is a heterogeneous disease classified into two broad molecular subtype categories, basal and luminal, with critical treatment and prognostic implications. Recent studies have shown the utility of immunohistochemistry in predicting bladder cancer molecular subtypes, with a two-marker approach using GATA3 and CK5/6 showing over 80% reliability. In the current study, we calculated the accuracy of uroplakin II (UPII), a marker of urothelial differentiation, with different scores (0: <1%, 1+: 1-10%, 2+: 10-50%, 3+: >50%) to predict RNA-based luminal versus basal subtypes in a cohort of muscle-invasive bladder cancer-received neoadjuvant chemotherapy followed by radical cystectomy. The 1% cutoff of the UPII stain predicts the luminal subtype with the sensitivity and specificity of 95% and 56%, respectively. With a UPII cutoff of 10%, the sensitivity and specificity were 93% and 81%, respectively, and with a UPII cutoff of 50%, the sensitivity and specificity were 91% and 96%, respectively. The prediction performance of UPII was better than either GATA3 or CK5/6. There was no significant difference in prognoses between UPII 0-2+ and UPII 3+ patients in this cohort. The current study shows that evaluating the staining proportion score of UPII can accurately predict basal and luminal subtypes of muscle-invasive bladder cancer.

Cancer genomic profiling identified dihydropyrimidine dehydrogenase deficiency in bladder cancer promotes sensitivity to gemcitabine.

Chemotherapy is a standard therapy for muscle-invasive bladder cancer (MIBC). However, genomic alterations associated with chemotherapy sensitivity in MIBC have not been fully explored. This study aimed to investigate the genomic landscape of MIBC in association with the response to chemotherapy and to explore the biological role of genomic alterations. Genomic alterations in MIBC were sequenced by targeted exome sequencing of 409 genes. Gene expression in MIBC tissues was analyzed by western blotting, immunohistochemistry, and RNA microarray. Cellular sensitivity to gemcitabine and gemcitabine metabolite was examined in bladder cancer cells after modulation of candidate gene. Targeted exome sequencing in 20 cases with MIBC revealed various genomic alterations including pathogenic missense mutation of DPYD gene encoding dihydropyrimidine dehydrogenase (DPD). Conversely, high DPYD and DPD expression were associated with poor response to gemcitabine-containing chemotherapy among patients with MIBC, as well as gemcitabine resistance in bladder cancer cells. DPD suppression rendered cells sensitive to gemcitabine, while DPD overexpression made cells gemcitabine-resistant through reduced activity of the cytotoxic gemcitabine metabolite difluorodeoxycytidine diphosphate. This study revealed the novel role of DPD in gemcitabine metabolism. It has been suggested that DPYD genomic alterations and DPD expression are potential predictive biomarkers in gemcitabine treatment.