Early-life external exposome in children 2-5 years old in Colombia.

Exposome studies are advancing in high-income countries to understand how multiple environmental exposures impact health. However, there is a significant research gap in low- and middle-income and tropical countries. We aimed to describe the spatiotemporal variation of the external exposome, its correlation structure between and within exposure groups, and its dimensionality. A one-year follow-up cohort study of 506 children under 5 in two cities in Colombia was conducted to evaluate asthma, acute respiratory infections, and DNA damage. We examined 48 environmental exposures during pregnancy and 168 during childhood in eight exposure groups, including atmospheric pollutants, natural spaces, meteorology, built environment, traffic, indoor exposure, and socioeconomic capital. The exposome was estimated using geographic information systems, remote sensing, spatiotemporal modeling, and questionnaires. The median age of children at study entry was 3.7 years (interquartile range: 2.9-4.3). Air pollution and natural spaces exposure decreased from pregnancy to childhood, while socioeconomic capital increased. The highest median correlations within exposure groups were observed in meteorology (r = 0.85), traffic (r = 0.83), and atmospheric pollutants (r = 0.64). Important correlations between variables from different exposure groups were found, such as atmospheric pollutants and meteorology (r = 0.76), natural spaces (r = -0.34), and the built environment (r = 0.53). Twenty principal components explained 70%, and 57 explained 95% of the total variance in the childhood exposome. Our findings show that there is an important spatiotemporal variation in the exposome of children under 5. This is the first characterization of the external exposome in urban areas of Latin America and highlights its complexity, but also the need to better characterize and understand the exposome in order to optimize its analysis and applications in local interventions aimed at improving the health conditions and well-being of the child population and contributing to environmental health decision-making.

Routine Clinically Detected Increased ROS1 Transcripts Are Related With ROS1 Expression by Immunohistochemistry and Associated With EGFR Mutations in Lung Adenocarcinoma.

Introduction: Translocations of the ROS1 gene were found to drive tumorigenesis in 1% to 2% of lung adenocarcinoma. In clinical practice, ROS1 rearrangements are often screened by immunohistochemistry (IHC) before confirmation with either fluorescence in situ hybridization or molecular techniques. This screening test leads to a non-negligible number of cases that have equivocal or positive ROS1 IHC, without ROS1 translocation. Methods: In this study, we have analyzed retrospectively 1021 cases of nonsquamous NSCLC having both ROS1 IHC and molecular analysis using next-generation sequencing. Results: ROS1 IHC was negative in 938 cases (91.9%), equivocal in 65 cases (6.4%), and positive in 18 cases (1.7%). Among these 83 equivocal or positive cases, only two were ROS1 rearranged, leading to a low predictive positive value of the IHC test (2%). ROS1-positive IHC was correlated with an increased mRNA ROS1 transcripts. Moreover, we have found a mean statistically significant relationship between ROS1 expression and EGFR gene mutations, suggesting a crosstalk mechanism between these oncogenic driver molecules. Conclusion: This study demonstrates that ROS1 IHC represents true ROS1 mRNA expression, and raises the question of a potential benefit of combined targeted therapy in EGFR-mutated NSCLC.

Consensus Recommendations to Optimize the Detection and Reporting of NTRK Gene Fusions by RNA-Based Next-Generation Sequencing.

The detection of gene fusions by RNA-based next-generation sequencing (NGS) is an emerging method in clinical genetic laboratories for oncology biomarker testing to direct targeted therapy selections. A recent Canadian study (CANTRK study) comparing the detection of NTRK gene fusions on different NGS assays to determine subjects' eligibility for tyrosine kinase TRK inhibitor therapy identified the need for recommendations for best practices for laboratory testing to optimize RNA-based NGS gene fusion detection. To develop consensus recommendations, representatives from 17 Canadian genetic laboratories participated in working group discussions and the completion of survey questions about RNA-based NGS. Consensus recommendations are presented for pre-analytic, analytic and reporting aspects of gene fusion detection by RNA-based NGS.

Next-generation sequencing of non-small cell lung cancer at a Quebec health care cancer centre.

BACKGROUND: Lung cancer is the leading cause of cancer death in both men and women. Quebec has the highest lung cancer mortality out of all provinces in Canada, believed to be caused by higher smoking rates. Molecular testing for lung cancer is standard of care due to the discovery of actionable driver mutations that can be targeted with tyrosine kinase inhibitors. To date, no detailed molecular testing characterization of Quebec patients with lung cancer using next generation sequencing (NGS) has been performed. MATERIALS AND METHODS: The aim of this study was to describe the genomic landscape of patients with lung cancer (n = 997) who underwent NGS molecular testing at a tertiary care center in Quebec and to correlate it with clinical and pathology variables. RESULTS: Compared to 10 other NGS studies found through a structured search strategy, our cohort had a higher prevalence of KRAS mutations (39.2%) compared to most geographical locations. Additionally, we observed a significant positive association between decreasing age and a higher proportion of KRAS G12C mutations. CONCLUSION: Overall, it remains important to assess institutional rates of actionable driver mutations to help guide governing bodies, fuel clinical trials and create benchmarks for expected rates as quality metrics.

Characterization of the external exposome and its contribution to the clinical respiratory and early biological effects in children: The PROMESA cohort study protocol.

BACKGROUND: Air pollution contains a mixture of different pollutants from multiple sources. However, the interaction of these pollutants with other environmental exposures, as well as their harmful effects on children under five in tropical countries, is not well known. OBJECTIVE: This study aims to characterize the external exposome (ambient and indoor exposures) and its contribution to clinical respiratory and early biological effects in children. MATERIALS AND METHODS: A cohort study will be conducted on children under five (n = 500) with a one-year follow-up. Enrolled children will be followed monthly (phone call) and at months 6 and 12 (in person) post-enrolment with upper and lower Acute Respiratory Infections (ARI) examinations, asthma development, asthma control, and genotoxic damage. The asthma diagnosis will be pediatric pulmonologist-based and a standardized protocol will be used. Exposure, effect, and susceptibility biomarkers will be measured on buccal cells samples. For environmental exposures PM2.5 will be sampled, and questionnaires, geographic information, dispersion models and Land Use Regression models for PM2.5 and NO2 will be used. Different statistical methods that include Bayesian and machine learning techniques will be used for the ambient and indoor exposures-and outcomes. This study was approved by the ethics committee at Universidad Pontificia Bolivariana. EXPECTED STUDY OUTCOMES/FINDINGS: To estimate i) The toxic effect of particulate matter transcending the approach based on pollutant concentration levels; ii) The risk of developing an upper and lower ARI, based on different exposure windows; iii) A baseline of early biological damage in children under five, and describe its progression after a one-year follow-up; and iv) How physical and chemical PM2.5 characteristics influence toxicity and children's health.

CANTRK: A Canadian Ring Study to Optimize Detection of NTRK Gene Fusions by Next-Generation RNA Sequencing.

The Canadian NTRK (CANTRK) study is an interlaboratory comparison ring study to optimize testing for neurotrophic receptor tyrosine kinase (NTRK) fusions in Canadian laboratories. Sixteen diagnostic laboratories used next-generation sequencing (NGS) for NTRK1, NTRK2, or NTRK3 fusions. Each laboratory received 12 formalin-fixed, paraffin-embedded tumor samples with unique NTRK fusions and two control non-NTRK fusion samples (one ALK and one ROS1). Laboratories used validated protocols for NGS fusion detection. Panels included Oncomine Comprehensive Assay v3, Oncomine Focus Assay, Oncomine Precision Assay, AmpliSeq for Illumina Focus, TruSight RNA Pan-Cancer Panel, FusionPlex Lung, and QIAseq Multimodal Lung. One sample was withdrawn from analysis because of sample quality issues. Of the remaining 13 samples, 6 of 11 NTRK fusions and both control fusions were detected by all laboratories. Two fusions, WNK2::NTRK2 and STRN3::NTRK2, were not detected by 10 laboratories using the Oncomine Comprehensive or Focus panels, due to absence of WNK2 and STRN3 in panel designs. Two fusions, TPM3::NTRK1 and LMNA::NTRK1, were challenging to detect on the AmpliSeq for Illumina Focus panel because of bioinformatics issues. One ETV6::NTRK3 fusion at low levels was not detected by two laboratories using the TruSight Pan-Cancer Panel. Panels detecting all fusions included FusionPlex Lung, Oncomine Precision, and QIAseq Multimodal Lung. The CANTRK study showed competency in detection of NTRK fusions by NGS across different panels in 16 Canadian laboratories and identified key test issues as targets for improvements.

An integrated model of acinar to ductal metaplasia-related N7-methyladenosine regulators predicts prognosis and immunotherapy in pancreatic carcinoma based on digital spatial profiling.

Acinar-to-ductal metaplasia (ADM) is a recently recognized, yet less well-studied, precursor lesion of pancreatic ductal adenocarcinoma (PDAC) developed in the setting of chronic pancreatitis. Through digital spatial mRNA profiling, we compared ADM and adjacent PDAC tissues from patient samples to unveil the bridging genes during the malignant transformation of pancreatitis. By comparing the bridging genes with the 7-methylguanosine (m7G)-seq dataset, we screened 19 m7G methylation genes for a subsequent large sample analysis. We constructed the "m7G score" model based on the RNA-seq data for pancreatic cancer in The Cancer Genome Atlas (TCGA) database and The Gene Expression Omnibus (GEO) database. Tumors with a high m7G score were characterized by increased immune cell infiltration, increased genomic instability, higher response rate to combined immune checkpoint inhibitors (ICIs), and overall poor survival. These findings indicate that the m7G score is associated with tumor invasiveness, immune cell infiltration, ICI treatment response, and overall patients' survival. We also identified FN1 and ITGB1 as core genes in the m7Gscore model, which affect immune cell infiltration and genomic instability not only in pancreatic cancer but also in pan-cancer. FN1 and ITGB1 can inhibit immune T cell activition by upregulation of macrophages and neutrophils, thereby leading to immune escape of pancreatic cancer cells and reducing the response rate of ICI treatment.

Unique Case of Congenital Langerhans Cell Histiocytosis Presenting as Intrauterine Fetal Demise.

Congenital Langerhans cell histiocytosis (LCH) (formerly called Letterer-Siwe disease) is characterized by a clonal proliferation of Langerhans cells occurring in children at birth and manifests typically with multifocal cutaneous lesions, hepatosplenomegaly, lymphadenopathy, pulmonary lesions, and destructive osteolytic bone lesions. We present a case of LCH involving multiple systems high-risk organs (LCH MS-RO+), in a 32-week stillborn from a 20-year-old G2A1. The fetus was mildly hydropic and pale. Apart from maceration, the skin showed multiple targetoid lesions over the face, trunk, and limbs. There was hepatosplenomegaly and a pale brain. The placenta was large and bulky. Despite severe autolysis, histological examination showed disseminated histiocytes with multinucleated giant cells in the skin, lungs, thymus, mesenteric lymph nodes, spleen, and brain. By immunohistochemistry, the histiocytes were positive for S100, CD1a, and Langerin (CD207), confirming the diagnosis of LCH. There was extramedullary hematopoiesis in the spleen, brain, and placenta. Targeted next-generation sequencing performed on thymic DNA did not show the BRAF p.V600E variant but did show the MAP2K1 p.F53_Q58delinsL. Infants with LCH pose a diagnostic challenge due to their heterogeneous presentations. Our case is unusual in that the newborn presented with severe multiorgan involvement including brain and intrauterine death. LCH is still poorly understood requiring further genetic and molecular studies.

Integrating NGS-derived mutational profiling in the diagnosis of multiple lung adenocarcinomas.

MICROABSTRACT: Integration of Next Generation Sequencing (NGS) information for use in distinguishing between Multiple Primary Lung Cancer and intrapulmonary metastasis was evaluated. We used a probabilistic model, comprehensive histologic assessment and NGS to classify patients. Integrating NGS data confirmed initial diagnosis (n = 41), revised the diagnosis (n = 12), while resulted in non-informative data (n = 8). Accuracy of diagnosis can be significantly improved with integration of NGS data. BACKGROUND: Distinguishing between multiple primary lung cancers (MPLC) and intrapulmonary metastases (IPM) is challenging. The goal of this study was to evaluate how Next Generation Sequencing (NGS) information may be integrated in the diagnostic strategy. PATIENTS AND METHODS: Patients with multiple lung adenocarcinomas were classified using both the comprehensive histologic assessment and NGS. We computed the joint probability of each pair having independent mutations by chance (thus being classified as MPLC). These probabilities were computed using the marginal mutation rates of each mutation, and the known negative dependencies between driver genes and different gene loci. With these NGS-driven data, cases were re-classified as MPLC or IPM. RESULTS: We analyzed 61 patients with a total of 131 tumors. The most frequent mutation was KRAS (57.3%) which occured at a rate higher than expected (p < 0.001) in lung cancer. No mutation was detected in 25/131 tumors (19.1%). Discordant molecular findings between tumor sites were found in 46 patients (75.4%); 11 patients (18.0%) had concordant molecular findings, and 4 patients (6.6%) had concordant molecular findings at 2 of the 3 sites. After integration of the NGS data, the initial diagnosis was confirmed for 41 patients (67.2%), the diagnosis was revised for 12 patients (19.7%) or was considered as non-informative for 8 patients (13.1%). CONCLUSION: Integrating the information of NGS data may significantly improve accuracy of diagnosis and staging.

REG3A/REG3B promotes acinar to ductal metaplasia through binding to EXTL3 and activating the RAS-RAF-MEK-ERK signaling pathway.

Persistent acinar to ductal metaplasia (ADM) is a recently recognized precursor of pancreatic ductal adenocarcinoma (PDAC). Here we show that the ADM area of human pancreas tissue adjacent to PDAC expresses significantly higher levels of regenerating protein 3A (REG3A). Exogenous REG3A and its mouse homolog REG3B induce ADM in the 3D culture of primary human and murine acinar cells, respectively. Both Reg3b transgenic mice and REG3B-treated mice with caerulein-induced pancreatitis develop and sustain ADM. Two out of five Reg3b transgenic mice with caerulein-induced pancreatitis show progression from ADM to pancreatic intraepithelial neoplasia (PanIN). Both in vitro and in vivo ADM models demonstrate activation of the RAS-RAF-MEK-ERK signaling pathway. Exostosin-like glycosyltransferase 3 (EXTL3) functions as the receptor for REG3B and mediates the activation of downstream signaling proteins. Our data indicates that REG3A/REG3B promotes persistent ADM through binding to EXTL3 and activating the RAS-RAF-MEK-ERK signaling pathway. Targeting REG3A/REG3B, its receptor EXTL3, or other downstream molecules could interrupt the ADM process and prevent early PDAC carcinogenesis.

Methylation guide RNA evolution in archaea: structure, function and genomic organization of 110 C/D box sRNA families across six Pyrobaculum species.

Archaeal homologs of eukaryotic C/D box small nucleolar RNAs (C/D box sRNAs) guide precise 2'-O-methyl modification of ribosomal and transfer RNAs. Although C/D box sRNA genes constitute one of the largest RNA gene families in archaeal thermophiles, most genomes have incomplete sRNA gene annotation because reliable, fully automated detection methods are not available. We expanded and curated a comprehensive gene set across six species of the crenarchaeal genus Pyrobaculum, particularly rich in C/D box sRNA genes. Using high-throughput small RNA sequencing, specialized computational searches and comparative genomics, we analyzed 526 Pyrobaculum C/D box sRNAs, organizing them into 110 families based on synteny and conservation of guide sequences which determine methylation targets. We examined gene duplications and rearrangements, including one family that has expanded in a pattern similar to retrotransposed repetitive elements in eukaryotes. New training data and inclusion of kink-turn secondary structural features enabled creation of an improved search model. Our analyses provide the most comprehensive, dynamic view of C/D box sRNA evolutionary history within a genus, in terms of modification function, feature plasticity, and gene mobility.

A Phase 2 Trial of Neoadjuvant Temozolomide Followed by Hypofractionated Accelerated Radiation Therapy With Concurrent and Adjuvant Temozolomide for Patients With Glioblastoma.

PURPOSE: We performed a phase 2 trial of neoadjuvant temozolomide (TMZ), followed by hypofractionated accelerated radiation therapy (HART) with concurrent TMZ, and adjuvant TMZ in patients with newly diagnosed glioblastoma to determine whether neoadjuvant TMZ would safely improve outcomes in this group of patients prior to subsequent cytotoxic therapy. METHODS AND MATERIALS: Adult patients with newly diagnosed glioblastoma and a Karnofsky Performance Status >60 were eligible. Neoadjuvant TMZ administration started 2 to 3 weeks from surgery at a daily dose of 75 mg/m2 for 2 weeks prior to delivery of HART (60 Gy in 20 daily fractions) with concurrent and adjuvant TMZ. The primary endpoints were feasibility and toxicity. The secondary endpoints included overall survival (OS) and progression-free survival. RESULTS: Fifty patients were accrued. The median follow-up period was 44.0 months for patients at risk and 22.3 months for all 50 patients. Except for 1 patient in whom infection developed and another patient with progression during HART, all patients completed protocol therapy as planned. The median OS and progression-free survival were 22.3 months (95% confidence interval, 14.6-42.7 months) and 13.7 months (95% confidence interval, 8.0-33.3 months), respectively. The 4-year OS rates were 30.4% for the entire cohort and 53.3% and 14.0% for patients with methylated (n=21) and unmethylated (n=27) MGMT gene promoter tumors, respectively. One patient had grade 5 pancytopenia during HART, and another patient had transient grade 4 hepatotoxicity. A second surgical procedure was performed in 13 patients: 2 had intracranial infection, 3 had recurrences, 4 had recurrences and radiation-induced damage, and 4 had only radiation-induced damage. CONCLUSIONS: This novel approach of neoadjuvant TMZ is associated with an encouraging favorable long-term survival with acceptable toxicity. A future comparative trial of the efficacy of this regimen is warranted.

The bovine immunodeficiency virus Rev protein: identification of a novel nuclear import pathway and nuclear export signal among retroviral Rev/Rev-like proteins.

The Rev protein is essential for the replication of lentiviruses. Rev is a shuttling protein that transports unspliced and partially spliced lentiviral RNAs from the nucleus to the cytoplasm via the nucleopore. To transport these RNAs, the human immunodeficiency virus type 1 (HIV-1) Rev uses the karyopherin ß family importin ß and CRM1 proteins that interact with the Rev nuclear localization signal (NLS) and nuclear exportation signal (NES), respectively. Recently, we reported the presence of new types of bipartite NLS and nucleolar localization signal (NoLS) in the bovine immunodeficiency virus (BIV) Rev protein. Here we report the characterization of the nuclear import and export pathways of BIV Rev. By using an in vitro nuclear import assay, we showed that BIV Rev is transported into the nucleus by a cytosolic and energy-dependent importin α/ß classical pathway. Results from glutathione S-transferase (GST) pulldown assays that showed the binding of BIV Rev with importins α3 and α5 were in agreement with those from the nuclear import assay. We also identified a leptomycin B-sensitive NES in BIV Rev, which indicates that the protein is exported via CRM1 like HIV-1 Rev. Mutagenesis experiments showed that the BIV Rev NES maps between amino acids 109 to 121 of the protein. Remarkably, the BIV Rev NES was found to be of the cyclic AMP (cAMP)-dependent protein kinase inhibitor (PKI) type instead of the HIV-1 Rev type. In summary, our data showed that the nuclear import mechanism of BIV Rev is novel among Rev proteins characterized so far in lentiviruses.

Molecular and biological aspects of the bovine immunodeficiency virus.

The bovine immunodeficiency virus (BIV) was isolated in 1969 from a cow, R-29, with a wasting syndrome suggesting bovine leucosis. The virus, first designated bovine visna-like virus, remained unstudied until HIV was discovered in 1983. Then, it was demonstrated in 1987 that the bovine R-29 isolate was a lentivirus with striking similarity to the human immunodeficiency virus (HIV). Moreover, BIV has the most complex genomic structure among all identified lentiviruses shown by several regulatory/accessory genes encoding proteins, some of which are involved in the regulation of virus gene expression. This manuscript aims to review biological and molecular aspects of BIV, with emphasis on regulatory/accessory viral genes/proteins which are involved in virus expression.

The bovine immunodeficiency virus rev protein: identification of a novel lentiviral bipartite nuclear localization signal harboring an atypical spacer sequence.

The bovine immunodeficiency virus (BIV) Rev protein (186 amino acids [aa] in length) is involved in the nuclear exportation of partially spliced and unspliced viral RNAs. Previous studies have shown that BIV Rev localizes in the nucleus and nucleolus of infected cells. Here we report the characterization of the nuclear/nucleolar localization signals (NLS/NoLS) of this protein. Through transfection of a series of deletion mutants of BIV Rev fused to enhanced green fluorescent protein and fluorescence microscopy analyses, we were able to map the NLS region between aa 71 and 110 of the protein. Remarkably, by conducting alanine substitution of basic residues within the aa 71 to 110 sequence, we demonstrated that the BIV Rev NLS is bipartite, maps to aa 71 to 74 and 95 to 101, and is predominantly composed of arginine residues. This is the first report of a bipartite Rev (or Rev-like) NLS in a lentivirus/retrovirus. Moreover, this NLS is atypical, as the length of the sequence between the motifs composing the bipartite NLS, e.g., the spacer sequence, is 20 aa. Further mutagenesis experiments also identified the NoLS region of BIV Rev. It localizes mainly within the NLS spacer sequence. In addition, the BIV Rev NoLS sequence differs from the consensus sequence reported for other viral and cellular nucleolar proteins. In summary, we conclude that the nucleolar and nuclear localizations of BIV Rev are mediated via novel NLS and NoLS motifs.