Mutations In Gene Research Articles

Insights on the Correlation between Mitochondrial Dysfunction and the Progression of Parkinson's Disease.

The aetiology of a progressive neuronal Parkinson's disease has been discussed in several studies. However, due to the multiple risk factors involved in its development, such as environmental toxicity, parental inheritance, misfolding of protein, ageing, generation of reactive oxygen species, degradation of dopaminergic neurons, formation of neurotoxins, mitochondria dysfunction, and genetic mutations, its mechanism of involvement is still discernible. Therefore, this study aimed to review the processes or systems that are crucially implicated in the conversion of MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) into its lethal form, which directly blockades the performance of mitochondria, leading to the formation of oxidative stress in the dopaminergic neurons of substantia nigra pars compacta (SNpc) and resulting in the progression of an incurable Parkinson's disease. This review also comprises an overview of the mutated genes that are frequently associated with mitochondrial dysfunction and the progression of Parkinson's disease. Altogether, this review would help future researchers to develop an efficient therapeutic approach for the management of Parkinson's disease via identifying potent prognostic and diagnostic biomarkers.

Oxidative Stress and Dopaminergic Metabolism: A Major PD Pathogenic Mechanism and Basis of Potential Antioxidant Therapies

Reactive oxygen species (ROS)-induced oxidative stress triggers the vicious cycle leading to the degeneration of dopaminergic neurons in the nigra pars compacta. ROS produced during the metabolism of dopamine is immediately neutralized by the endogenous antioxidant defense system (EADS) under physiological conditions. Aging decreases the vigilance of EADS and makes the dopaminergic neurons more vulnerable to oxidative stress. As a result, ROS left over by EADS oxidize the dopamine-derived catechols and produces a number of reactive dopamine quinones, which are precursors to endogenous neurotoxins. In addition, ROS causes lipid peroxidation, uncoupling of the electron transport chain, and DNA damage, which lead to mitochondrial dysfunction, lysosomal dysfunction, and synaptic dysfunction. The mutations in genes such as DNAJC6, SYNJ1, SH3GL2, LRRK2, PRKN, and VPS35 caused by ROS have been associated with synaptic dysfunction and the pathogenesis of Parkinson’s disease (PD). The available drugs that are used against PD can only delay the progression of the disease, but they produce various side effects. Through their antioxidant activity, flavonoids can substantiate the EADS of dopaminergic neurons and disrupt the vicious cycle incepted by oxidative stress. In this review, we show how the oxidative metabolism of dopamine generates ROS and dopamine-quinones, which then exert unrestrained OS, causing mutations in several genes involved in the proper functioning of mitochondrion, synapse, and lysosome. Besides, we also present some examples of approved drugs used for the treatment of PD, therapies in the clinical trial phase, and an update on the flavonoids that have been tested to boost the EADS of dopaminergic neurons.

Unraveling the Role of Neuroligin3 in Autism Spectrum Disorders: Pathophysiological Insights and Targeted Therapies.

Autism Spectrum Disorder is a neurodevelopmental disorder characterized by impaired social and communication skills, repetitive behaviors, and/or restricted interests with a prevalence of as high as 1% of children. Autism spectrum has strongly associated with genetic factors and exhibits wide clinical and heterogeneous genetic architecture. Most genes associated with Autism are involved in neuronal and synaptic development. The neuroligin3, the sex-linked gene on the X chromosome, was the first gene to be associated with a monogenic form of Autism. Neuroligin3 is a postsynaptic cell adhesion protein involved in synapse transmission, brain formation, and neuronal development. In this review, we provide recent findings on different mutations in the Neuroligin3 gene linked to Autism spectrum disorder and their molecular pathway effect. We also give the behavioral, and synaptic alterations reported in the Neuroligin3 animal model of Autism and the potential therapeutic strategies targeting the biological processes and the main symptoms of autism spectrum disorder. In addition, we discuss the use of novel technologies like induced pluripotent stem cells from Autistic patients that have the potential to differentiate in human neurons and therefore have a variety of applications in therapy and biomedical studies to search specific biomarkers, and develop systems for screening chemical molecules in human cells to discover target therapies.

Two lysin motif extracellular (LysMe) proteins are deployed in rice to facilitate arbuscular mycorrhizal symbiosis.

During arbuscular mycorrhizal (AM) symbiosis, plant innate immunity is modulated to a prime state to allow for fungal colonization. The underlying mechanisms remain to be further explored. In this study, two rice genes encoding LysM extracellular (LysMe) proteins were investigated. By obtaining OsLysMepro:GUS transgenic plants and generating oslysme1, oslysme2 and oslysme1oslysme2 mutants via CRISPR/Cas9 technique, OsLysMe genes were revealed to be specifically induced in the arbusculated cells and mutations in either gene caused significantly reduced root colonization rate by AM fungus Rhizophagus irregularis. Overexpression of OsLysMe1 or OsLysMe2 dramatically increased the colonization rates in rice and Medicago truncatula. The electrophoretic mobility shift assay and dual-luciferase reporter assay supported that OsLysMe genes are regulated by OsWRI5a. Either OsLysMe1 or OsLysMe2 can efficiently rescue the impaired AM phenotype of the mtlysme2 mutant, supporting a conserved function of LysMe across monocotyledonous and dicotyledonous plants. The co-localization of OsLysMe proteins with the apoplast marker SP-OsRAmy3A implies their probable localization to the periarbuscular space (PAS) during symbiosis. Relative to the fungal biomass marker RiTEF, some defense-related genes showed disproportionately high expression levels in the oslysme mutants. These data support that rice plants deploy two OsLysMe proteins to facilitate AM symbiosis, likely by diminishing plant defense responses.

The impact of obesity-induced inflammation on clonal hematopoiesis.

This review meticulously delves into existing literature and recent findings to elucidate the intricate link between obesity and clonal hematopoiesis of indeterminate potential (CHIP) associated clonal hematopoiesis. It aims to enhance our comprehension of this multifaceted association, offering insights into potential avenues for future research and therapeutic interventions. Recent insights reveal that mutations in CHIP-associated genes are not limited to symptomatic patients but are also present in asymptomatic individuals. This section focuses on the impact of obesity-induced inflammation and fatty bone marrow (FBM) on the development of CHIP-associated diseases. Common comorbidities such as obesity, diabetes, and infection, fostering pro-inflammatory environments, play a pivotal role in the acceleration of these pathologies. Our research underscores a notable association between CHIP and an increased waist-to-hip ratio (WHR), emphasizing the link between obesity and myeloid leukemia. Recent studies highlight a strong correlation between obesity and myeloid leukemias in both children and adults, with increased risks and poorer survival outcomes in overweight individuals. We discuss recent insights into how CHIP-associated pathologies respond to obesity-induced inflammation, offering implications for future studies in the intricate field of clonal hematopoiesis.

Real-world Study on the Effect of PARPi as Maintenance Therapy on Platinum Sensitivity after First- and Second-line Chemotherapy in Patients with Recurrent High-grade Serous Epithelial Ovarian Cancer.

This study investigated the effect of poly(ADP-ribose) polymerase inhibitors (PARPi) as maintenance therapy after first- and second-line chemotherapy on platinum sensitivity in patients with recurrent high-grade serous epithelial ovarian cancer (rHGSOC). This study retrospectively analyzed 172 patients with rHGSOC treated at Zhejiang Cancer Hospital and Jiaxing Maternity and Child Health Care Hospital between January 2017 and December 2021. The 1st-PARPi group comprised patients who received a PARPi as maintenance therapy after first-line chemotherapy (n=23), and the 1st-control group comprised those who did not (n = 105). Similarly, the 2nd-PARPi group comprised patients not given a PARPi in their first-line treatment (n = 30), and the 2nd-control group comprised those who were given a PARPi (n = 89). Among the 23 patients in the 1st-PARPi group and the 105 patients in the 1st-control group, nine and 99 were platinum-sensitive, and 14 and six were platinum-resistant, respectively (hazard ratio [HR]: 14.46, P < 0.0001). Among the 30 patients in the 2nd-PARPi group and 89 patients in the 2nd-control group, 10 and 71 were platinum-sensitive, and 20 and 18 were platinumresistant, respectively (HR: 4.37, P < 0.0001). Age, stage, residual tumor, the courses of platinumbased chemotherapy, and breast cancer susceptibility gene mutations were not associated with platinum sensitivity when using a PARPi as maintenance therapy after first- and second-line chemotherapy. Patients with rHGSOC using a PARPi were more likely to be platinum-sensitive and develop platinum resistance independent of PARPi duration. Care should be taken when using a PARPi as maintenance therapy after first- and second-line chemotherapy.

Evolution of the pathogenic mold Aspergillus fumigatus on high copper levels identifies novel resistance genes.

Aspergillus fumigatus is the leading cause of severe mold infections in immunocompromised patients. This common fungus possesses innate attributes that allow it to evade the immune system, including its ability to survive the high copper (Cu) levels in phagosomes. Our previous work has revealed that under high Cu levels, the A. fumigatus transcription factor AceA is activated, inducing the expression of the copper exporter CrpA to expel excess Cu. To identify additional elements in Cu resistance, we evolved A. fumigatus wild-type and mutant ΔaceA or ΔcrpA strains under increasing Cu concentrations. Sequencing of the resultant resistant strains identified both shared and unique evolutionary pathways to resistance. Reintroduction of three of the most common mutations in genes encoding Pma1 (plasma membrane H+-ATPase), Gcs1 (glutamate cysteine-ligase), and Cpa1 (carbamoyl-phosphate synthetase), alone and in combination, into wild-type A. fumigatus confirmed their additive role in conferring Cu resistance. Detailed analysis indicated that the pma1 mutation L424I preserves Pma1 H+-ATPase activity under high Cu concentrations and that the cpa1 mutation A37V confers a survival advantage to conidia in the presence of Cu. Interestingly, simultaneous mutations of all three genes did not alter virulence in infected mice. Our work has identified novel Cu-resistance pathways and provides an evolutionary approach for dissecting the molecular basis of A. fumigatus adaptation to diverse environmental challenges.IMPORTANCEAspergillus fumigatus is the most common mold infecting patients with weakened immunity. Infection is caused by the inhalation of mold spores into the lungs and is often fatal. In healthy individuals, spores are engulfed by lung immune cells and destroyed by a combination of enzymes, oxidants, and high levels of copper. However, the mold can protect itself by pumping out excess copper with specific transporters. Here, we evolved A. fumigatus under high copper levels and identified new genetic mutations that help it resist the toxic effects of copper. We studied how these mutations affect the mold's ability to resist copper and how they impact its ability to cause disease. This is the first such study in a pathogenic mold, and it gives us a better understanding of how it manages to bypass our body's defenses during an infection.

Integrated Antigenic and Nucleic Acid Detection in Single Virions and Extracellular Vesicles with Viral Content.

Virion-mediated outbreaks are imminent and despite rapid responses, continue to cause adverse symptoms and death. Therefore, tunable, sensitive, high-throughput assays are needed to help diagnose future virion-mediated outbreaks. Herein, it is developed a tunable in situ assay to selectively enrich virions and extracellular vesicles (EVs) and simultaneously detect antigens and nucleic acids at a single-particle resolution. The Biochip Antigen and RNA Assay (BARA) enhanced sensitivities compared to quantitative reverse-transcription polymerase chain reaction (qRT-PCR), enabling the detection of virions in asymptomatic patients, genetic mutations in single virions, and enabling the continued long-term expression of viral RNA in the EV-enriched subpopulation in the plasma of patients with post-acute sequelae of the coronavirus disease of 2019 (COVID-19). BARA revealed highly accurate diagnoses of COVID-19 by simultaneously detecting the spike glycoprotein and nucleocapsid-encoding RNA in saliva and nasopharyngeal swab samples. Altogether, the single-particle detection of antigens and viral RNA provides a tunable framework for the diagnosis, monitoring, and mutation screening of current and future outbreaks.

Base editing correction of OCRL in Lowe syndrome: ABE-mediated functional rescue in patient-derived fibroblasts.

Lowe syndrome, a rare X-linked multisystem disorder presenting with major abnormalities in the eyes, kidneys, and central nervous system, is caused by mutations in OCRL gene (NG_008638.1). Encoding an inositol polyphosphate 5-phosphatase, OCRL catalyzes the hydrolysis of PI(4,5)P2 into PI4P. There are no effective targeted treatments for Lowe syndrome. Here, we demonstrate a novel gene therapy for Lowe syndrome in patient fibroblasts using an adenine base editor (ABE) that can efficiently correct pathogenic point mutations. We show that ABE8e-NG-based correction of a disease-causing mutation in a Lowe patient-derived fibroblast line containing R844X mutation in OCRL gene, restores OCRL expression at mRNA and protein levels. It also restores cellular abnormalities that are hallmarks of OCRL dysfunction, including defects in ciliogenesis, microtubule anchoring, α-actinin distribution, and F-actin network. The study indicates that ABE-mediated gene therapy is a feasible treatment for Lowe syndrome, laying the foundation for therapeutic application of ABE in the currently incurable disease.

Involvement of ArlI, ArlJ, and CirA in archaeal type IV pilin-mediated motility regulation.

Many prokaryotes use swimming motility to move toward favorable conditions and escape adverse surroundings. Regulatory mechanisms governing bacterial flagella-driven motility are well-established; however, little is yet known about the regulation underlying swimming motility propelled by the archaeal cell surface structure, the archaella. Previous research showed that the deletion of the adhesion pilins (PilA1-6), subunits of the type IV pili cell surface structure, renders the model archaeon Haloferax volcanii non-motile. In this study, we used ethyl methanesulfonate mutagenesis and a motility assay to identify motile suppressors of the ∆pilA[1-6] strain. Of the eight suppressors identified, six contain missense mutations in archaella biosynthesis genes, arlI and arlJ. In trans expression of arlI and arlJ mutant constructs in the respective multi-deletion strains ∆pilA[1-6]∆arlI and ∆pilA[1-6]∆arlJ confirmed their role in suppressing the ∆pilA[1-6] motility defect. Additionally, three suppressors harbor co-occurring disruptive missense and nonsense mutations in cirA, a gene encoding a proposed regulatory protein. A deletion of cirA resulted in hypermotility, while cirA expression in trans in wild-type cells led to decreased motility. Moreover, quantitative real-time PCR analysis revealed that in wild-type cells, higher expression levels of arlI, arlJ, and the archaellin gene arlA1 were observed in motile early-log phase rod-shaped cells compared to non-motile mid-log phase disk-shaped cells. Conversely, ∆cirA cells, which form rods during both early- and mid-log phases, exhibited similar expression levels of arl genes in both growth phases. Our findings contribute to a deeper understanding of the mechanisms governing archaeal motility, highlighting the involvement of ArlI, ArlJ, and CirA in pilin-mediated motility regulation.IMPORTANCEArchaea are close relatives of eukaryotes and play crucial ecological roles. Certain behaviors, such as swimming motility, are thought to be important for archaeal environmental adaptation. Archaella, the archaeal motility appendages, are evolutionarily distinct from bacterial flagella, and the regulatory mechanisms driving archaeal motility are largely unknown. Previous research has linked the loss of type IV pili subunits to archaeal motility suppression. This study reveals three Haloferax volcanii proteins involved in pilin-mediated motility regulation, offering a deeper understanding of motility regulation in this understudied domain while also paving the way for uncovering novel mechanisms that govern archaeal motility. Understanding archaeal cellular processes will help elucidate the ecological roles of archaea as well as the evolution of these processes across domains.

SMARCA4 alterations in non-small cell lung cancer: a systematic review and meta-analysis

AimsA mutation in the SMARCA4 gene which encodes BRG1, a common catalytic subunit of switch/sucrose non-fermentable chromatin-remodelling complexes, plays a vital role in carcinogenesis. SMARCA4 mutations are present in approximately...

EGFR and K-Ras Gene Mutations in the Diagnosis of Non-Small Cell Lung Cancer and their Pathological Correlation

EGFR and K-Ras Gene Mutations in the Diagnosis of Non-Small Cell Lung Cancer and their Pathological Correlation

АТИПИЧНЫЙ ГЕМОЛИТИКО-УРЕМИЧЕСКИЙ СИНДРОМ У ДЕТЕЙ В РЕСПУБЛИКЕ БЕЛАРУСЬ: ПЕРВЫЙ ОПЫТ КОМПЛЕМЕНТБЛОКИРУЮЩЕЙ ТЕРАПИИ

Atypical hemolytic uremic syndrome (aHUS) is one of the most complex and severe forms of thrombotic microangiopathy with an unfavorable outcome in its natural course. The purpose of this research was to study the epidemiology, demographics, course and outcomes of aHUS in comparison with patients with typical hemolytic uremic syndrome (tHUS) as well as to conduct a personal analysis of all cases of aHUS and evaluate the response to therapy, including comple-ment-blocking with Eculizumab. Materials and methods used: the study was longitudinal, obser-vational and included all 349 cases of HUS in children in Belarus in 2015-2023. A comparative analysis of demographic and clinical data, laboratory results and outcomes was performed in pa-tients with HUS hospitalized at the Center for Pediatric Nephrology and Renal Replacement Therapy of the Republic of Belarus (Minsk, Belarus). Results: of 349 HUS cases, the proportion of aHUS was 3,7% (13). Children with aHUS were older (4,6 (1,6; 6,7) v. 2,7 (1,7; 4,8) y/o with tHUS) due to the portion of patients older than 5 y/o (46%). In aHUS, severe central nervous system disorders were more often observed (62% v. 14%, p=0,002), the development of critical conditions requiring transfer to mechanical ventilation (39% v. 9%, p=0,006), prolonged anuria with the need for dialysis therapy in 100% of cases and severe adverse outcomes (death or end-stage renal disease) during natural course (66,0% v. 2,7%, p&lt;0,001). The most common trigger for aHUS was acute intestinal infections in 54% of cases. A genetic study was performed in 9 (69%) children with aHUS and in 8 (89%) of them the CFHR3/CFHR1 deletions were detected: in 4 cases (3 hetero- and a single homozygous) and heterozygous pathogenic and probably patho-genic gene mutations, CFHR5 in 2 cases, CFH in a single case and combined CD46 and CFI in a single case as well. Antibodies to complement factor H were detected in 5 patients, 3 of which had a CFHR3/CFHR1 deletion. Therapy with a biosimilar of the original Eculizumab showed its effectiveness in aHUS: in 3 (100%) children it was possible to prevent the return of the disease in the kidney graft, in single patient who did not receive prophylaxis it was able to block the recur-rence of aHUS in the transplanted kidney while preserving its function, in 3 (100%) patients with late administration of treatment the urine output was restored after prolonged anuria (24, 33 and 59 days); in a single child with the antibody variant of aHUS, with early administration of the drug, renal function was preserved. No complications of complement blocking therapy were not-ed. Conclusions: the introduction into clinical practice of a biosimilar of the original Eculizumab in children in Belarus has significantly improved the outcomes and prognosis of the disease.

PfHDAC1 is an essential regulator of P. falciparum asexual proliferation and host cell invasion genes with a dynamic genomic occupancy responsive to artemisinin stress.

Malaria is a major public health problem, with the parasite Plasmodium falciparum causing most of the malaria-associated mortality. It is spread by the bite of infected mosquitoes and results in symptoms such as cyclic fever, chills, and headache. However, if left untreated, it can quickly progress to a more severe and life-threatening form. The World Health Organization currently recommends the use of artemisinin combination therapy, and it has worked as a gold standard for many years. Unfortunately, certain countries in southeast Asia and Africa, burdened with a high prevalence of malaria, have reported cases of drug-resistant infections. One of the major problems in controlling malaria is the emergence of artemisinin resistance. Population genomic studies have identified mutations in the Kelch13 gene as a molecular marker for artemisinin resistance. However, several reports thereafter indicated that Kelch13 is not the main mediator but rather hinted at transcriptional deregulation as a major determinant of drug resistance. Earlier, we identified PfGCN5 as a global regulator of stress-responsive genes, which are known to play a central role in artemisinin resistance generation. In this study, we have identified PfHDAC1, a histone deacetylase as a cell cycle regulator, playing an important role in artemisinin resistance generation. Taken together, our study identified key transcriptional regulators that play an important role in artemisinin resistance generation.

Inhibition of O -GlcNAc transferase activates type I interferon-dependent antitumor immunity by bridging cGAS-STING pathway.

The O -GlcNAc transferase (OGT) is an essential enzyme that mediates protein O -GlcNAcylation, a unique form of posttranslational modification of many nuclear and cytosolic proteins. Recent studies observed increased OGT and O -GlcNAcylation levels in a broad range of human cancer tissues compared to adjacent normal tissues, indicating a universal effect of OGT in promoting tumorigenesis. Here, we show that OGT is essential for tumor growth in immunocompetent hosts by repressing the cyclic GMP-AMP synthase (cGAS)-dependent DNA sensing pathway. We found that deletion of OGT ( Ogt -/- ) caused a marked reduction in tumor growth in both syngeneic tumor models and a genetic colorectal cancer (CRC) model induced by mutation of the Apc gene ( Apc min ). Pharmacological inhibition or genetic deletion of OGT induced a robust genomic instability (GIN), leading to cGAS-dependent production of the type I interferon (IFN-I) and IFN-stimulated genes (ISGs). As a result, deletion of Cgas or Sting from Ogt -/- cancer cells restored tumor growth, and this correlated with impaired CD8 + T cell-mediated antitumor immunity. Mechanistically, we found that OGT-dependent cleavage of host cell factor C1 (HCF-1) is required for the avoidance of GIN and IFN-I production in tumors. In summary, our results identify OGT-mediated genomic stability and activate cGAS-STING pathway as an important tumor cell-intrinsic mechanism to repress antitumor immunity.

Short-term treatment with Uncaria tomentosa aggravates the injury phenotype in mdx mice

Introduction: Uncaria tomentosa (Willd. ex Roem. &amp; Schult.) DC. (Rubiaceae) or UT is a medicinal plant with antiviral, antimutagenic, anti-inflammatory and antioxidant properties. Duchenne muscular dystrophy (DMD) is a severe muscle wasting disease caused by mutations in the dystrophin gene; this deficiency leads to sarcolemma instability, inflammation, muscle degeneration and fibrosis. Objective: Considering the importance of inflammation to dystrophy progression and the anti-inflammatory activity of UT, in the present study we evaluated whether oral administration of UT extract would ameliorate dystrophy in the mdx mice, a DMD model. Methods: Eight-week-old male mdx mice were submitted to 200 mg/kg body weight daily UT oral administration for 6 weeks. General histopathology was analysed, and muscle tumor necrosis factor α, transforming growth factor-β, myostatin and osteopontin transcript levels were assessed. The ability of mice to sustain limb tension to oppose their gravitational force was measured. Data were analysed with the unpaired Student’s t-test. Results: Morphologically, both untreated and UT-treated animals exhibited internalised nuclei, increased endomysial connective tissue and variations in muscle fibre diameters. Body weight and muscle strength were significantly reduced in the UT-treated animals. Blood creatine kinase was higher in UT-treated compared to untreated animals. In tibialis anterior, myostatin, transcript was more highly expressed in the UT-treated while in the diaphragm muscle, transforming growth factor-β transcripts were less expressed in the UT-treated. Conclusion: While previous studies identified anti-inflammatory, antiproliferative and anticarcinogenic UT effects, the extract indicates worsening of dystrophic muscles phenotype after short-term treatment in mdx mice.

Clinical and genetic analysis of a child with West syndrome due to a de novo variant of NEXMIF gene

To investigate the clinical features and genetic variant of a child with West syndrome due to a variant of NEXMIF gene. A child who was admitted to the First Medical Center of Chinese PLA General Hospital in March 2021 was selected as the study subject. Clinical data of the patient was collected. The child and his parents were subjected to whole exome sequencing. Candidate variant was verified by Sanger sequencing and pathogenicity analysis. The child, a 4-month-old boy, had presented with spastic seizures with no obvious cause. Abnormal EEG, severe hypsarrhythmia, and multiple spastic seizures were discovered. Cranial MRI revealed widening of the extracerebral space at the top of the frontal lobe. Physical examination revealed that the child could not hold his head up, and could not respond to sounds or follow objects with his eyes. He also has microcephaly, with height < 1 s. The child was diagnosed with West syndrome at a local hospital, and was given prednisone orally for 3 months, with seizures under control. Topiramate tablets were taken orally for maintenance treatment, and he has been seizure-free for 7 months. DNA sequencing revealed that he has harbored a de novo nonsense variant of c.982_c.983delTT (p.L328Dfs*23) in the NEXMIF gene. For children with West syndrome with severe developmental delay or even regression as the first symptoms, uncontrollable seizures and abnormal facial appearance, mutations of the NEXMIF gene should be suspected, and genetic testing can facilitate early diagnosis and treatment.

Clinicopathological characteristics of gangliogliomas with anaplastic morphology

Objective: To investigate the clinical, radiological, and pathological features of anaplastic gangliogliomas (AGGs) and to determine whether these tumors represent a distinct entity. Methods: Consecutive 667 cases of ganglioglioma (GG) diagnosed at the Xuanwu Hospital, Capital Medical University, Beijing, China between January 2015 and July 2023 were screened. Among these cases, 9 pathologically confirmed AGG cases were identified. Their clinical, radiological, treatment, and outcome data were analyzed retrospectively. Most of the tumor samples were subject to next-generation sequencing, while a subset of them were subject to DNA methylation profiling. Results: Among the 9 patients, there were five males and four females, with a median age of 8 years. Epileptic seizures (5/9) were the most frequently presented symptom. Radiological examinations showed three types of radiological manifestations: four cases showed abnormal MRI signals with no significant mass effects and mild enhancement; two cases demonstrated a mixed solid-cystic density lesion with peritumoral edema, which showed significant heterogeneous enhancement and obvious mass effects, and one case displayed cystic cavity formation with nodules on MRI, which showed evident enhancements. All cases exhibited mutations that were predicted to activate the MAP kinase signaling pathway, including seven with BRAF p.V600E mutation and two with NF1 mutation. Five AGGs with mutations involving the MAP kinase signaling pathway also had concurrent mutations, including three with CDKN2A homozygous deletion, one with a TERT promoter mutation, one with a H3F3A mutation, and one with a PTEN mutation. Conclusions: AGG exhibits a distinct spectrum of pathology, genetic mutations and clinical behaviors, differing from GG. Given these characteristics suggest that AGG may be a distinct tumor type, further expansion of the case series is needed. Therefore, a comprehensive integration of clinical, histological, and molecular analyses is required to correctly diagnose AGG. It will also help guide treatments and prognostication.

Correlation between common driver gene variations and clinicopathological typing in lung adenocarcinoma

Objective: To correlate the common driver gene variations in primary lung adenocarcinoma with their clinical characteristics and histopathological subtypes. Methods: There were 4 995 cases of primary lung adenocarcinoma diagnosed at Weifang People's Hospital of Shandong Province from January 2015 to December 2021 which were retrospectively analyzed. Among them 1 983 cases were evaluated for their histopathological subtype; 3 012 were analyzed for the correlation of their histopathological subtypes and corresponding driver gene variations, including invasive non-mucinous adenocarcinoma (INMA) and invasive mucinous adenocarcinoma (IMA), and morphologically, poorly-differentiated, moderately-differentiated and well-differentiated adenocarcinomas. Next-generation sequencing was used to detect variations in EGFR, KRAS, ALK, RET, ROS1, MET, HER2, or BRAF driver genes. Results: There were 2 384 males and 2 611 females. EGFR and ALK variations were more commonly found in female patients aged 60 years or older, with EGFR mutation rate in clinical stage Ⅰ (25.80%) significantly higher than in other stages (P<0.05). KRAS mutations were more commonly detected in male smokers aged 60 years or older, HER2 mutations were more commonly in patients younger than 60 years, and RET mutations were more commonly in non-smokers (all P<0.05). No correlation was found between ROS1, MET, and BRAF gene variations and their clinical characteristics (P>0.05). For the histopathological subtypes, among the 1 899 cases of acinar adenocarcinoma, EGFR mutation rate was the highest (67.30%) compared to the other genes. Exon 21 L858R and exon 19 del were the main mutation sites in IMA and INMA, with a higher mutation rate at exon 20 T790M (11.63%) in micropapillary adenocarcinoma. In IMA, KRAS had the highest overall mutation rate (43.80%), with statistically significant difference in mutation rates of exon 2 G12D and exon 2 G12V in acinar adenocarcinoma, solid, and IMA (P<0.05). KRAS mutation at various sites were higher in poorly differentiated groups compared to moderately- and well-differentiated groups (P<0.05). HER2 mutations were more commonly observed in acinar adenocarcinoma, papillary, and micropapillary adenocarcinoma of INMA. BRAF mutation was higher in micropapillary adenocarcinoma compared with other types (P<0.05). Conclusions: Variations in EGFR, ALK, KRAS, HER2, and RET in primary lung adenocarcinoma are associated with patients' age, smoking history, and clinical stage, and driver gene mutations vary among different histopathological subtypes. EGFR mutations are predominant in INMA, while KRAS mutations are predominant in IMA.

AcrAB-TolC efflux pump overexpression and tet(A) gene mutation increase tigecycline resistance in Klebsiella pneumoniae.

Tigecycline-non-susceptible Klebsiella pneumoniae (TNSKP) is increasing and has emerged as a global public health issue. However, the mechanism of tigecycline resistance remains unclear. The objective of this study was to investigate the potential role of efflux pump system in tigecycline resistance. 29 tigecycline-non-susceptible Klebsiella pneumoniae (TNSKP) strains were collected and their minimum inhibitory concentrations (MIC) were determined by the broth microdilution method. The ramR, acrR, rpsJ, tet(A), and tet(X) were amplified by polymerase chain reaction (PCR). The mRNA expression of different efflux pump genes and regulator genes were analyzed by real-time PCR. Additionally, KP14 was selected for genome sequencing. KP14 genes without acrB, oqxB, and TetA were modified using suicide plasmids and MIC of tigecycline of KP14 with target genes knocked out was investigated. It was found that MIC of tigecycline of 20 out of the 29 TNSKP strains decreased by over four folds once combined with phenyl-arginine-β-naphthylamide dihydrochloride (PaβN). Most strains exhibited upregulation of AcrAB and oqxAB efflux pumps. The strains with acrB, oqxB, and tetA genes knocked out were constructed, wherein the MIC of tigecycline of KP14∆acrB and KP14∆tetA was observed to be 2µg/mL (decreased by 16 folds), the MIC of tigecycline of KP14ΔacrBΔTetA was 0.25µg/mL (decreased by 128 folds), but the MIC of tigecycline of KP14∆oqxB remained unchanged at 32µg/mL. The majority of TNSKP strains demonstrated increased expression of AcrAB-TolC and oqxAB, while certain strains showed mutations in other genes associated with tigecycline resistance. In KP14, both overexpression of AcrAB-TolC and tet(A) gene mutation contributed to the mechanism of tigecycline resistance.