OBJECTIVES: To investigate the role and mechanism of Brahma-related gene 1 (Brg1) in regulating the Wnt/β-catenin signaling pathway in a bronchopulmonary dysplasia (BPD) model. METHODS: Wild-type C57BL/6 and Brg1^f1/f1 mice were randomly divided into four groups: wild-type control, wild-type BPD, Brg1^f1/f1 control, and Brg1^f1/f1 BPD (n=5 each). Immortalized mouse pulmonary alveolar type 2 cells (imPAC2) were cultured, and Brg1 gene was knocked down using lentivirus transfection technology. Cells were divided into three groups: control, empty vector, and Brg1 knockdown. Hematoxylin and eosin staining and immunofluorescence were used to detect pathological changes in mouse lung tissue. Western blot and real-time fluorescent quantitative PCR were used to measure Brg1 protein and mRNA expression levels in mouse lung tissue. Western blot and immunofluorescence were used to detect the expression of homeodomain-containing protein homeobox (HOPX), surfactant protein C (SPC), and Wnt/β-catenin signaling pathway proteins in mouse lung tissue and imPAC2 cells. The CCK8 assay was used to assess the proliferation of imPAC2 cells, and co-immunoprecipitation was performed to verify the interaction between Brg1 and β-catenin proteins in imPAC2 cells. RESULTS: Compared to the Brg1^f1/f1 control group and wild-type BPD group, the Brg1^f1/f1 BPD group showed increased alveolar diameter and SPC protein expression, and decreased relative density of pulmonary vasculature and HOPX protein expression (P<0.05). Compared to the control group, the Brg1 knockdown group showed increased cell proliferation ability, protein expression levels of SPC, Wnt5a and β-catenin, and β-catenin protein fluorescence intensity, along with decreased HOPX protein expression (P<0.05). An interaction between Brg1 and β-catenin proteins was confirmed. CONCLUSIONS The Brg1 gene may promote the proliferation of alveolar type 2 epithelial cells by regulating the Wnt/β-catenin signaling pathway, thus influencing the occurrence and development of BPD.
Animals ; DNA Helicases/genetics* ; Transcription Factors/genetics* ; Wnt Signaling Pathway/physiology* ; Nuclear Proteins/genetics* ; Mice ; Bronchopulmonary Dysplasia/etiology* ; Mice, Inbred C57BL ; beta Catenin/physiology* ; Disease Models, Animal ; Cell Proliferation ; Lung/pathology* ; Male

SMARCA4-deficient non small cell lung cancer (SMARCA4-dNSCLC) has recently garnered increasing attention due to its high malignancy and poor prognosis. The literature suggests that in non small cell lung cancer (NSCLC), the loss of SMARCA4 frequently co-occurs with mutations in KRAS, KEAP1, and STK11 rather than in EGFR, ALK, and ROS1. Herein, we present the first documented case of SMARCA4-dNSCLC accompanied with rare mutations of EGFR exon 20 S768I and exon 18 G719X. The patient achieved partial response with afatinib for 17 months. Our case highlights the importance of EGFR mutations in the precision targeted treatment of SMARCA4-dNSCLC.
Humans ; Afatinib/therapeutic use* ; Antineoplastic Agents/therapeutic use* ; Carcinoma, Non-Small-Cell Lung/pathology* ; DNA Helicases/genetics* ; ErbB Receptors/genetics* ; Lung Neoplasms/pathology* ; Mutation ; Nuclear Proteins/genetics* ; Transcription Factors/genetics*

Geminiviruses cause substantial crop yield losses worldwide. The replication initiator protein (Rep) encoded by geminiviruses is indispensable for geminiviral replication. The Rep protein encoded by beet severe curly top virus (BSCTV, genus Curtovirus, family Geminiviridae) induces VARIANT IN METHYLATION 5 (VIM5) expression in Arabidopsis leaves upon BSCTV infection. VIM5 functions as a ubiquitination-related E3 ligase to promote the proteasomal degradation of methyltransferases, resulting in reduction of methylation levels in the BSCTV C2-3 promoter. However, the specific domains of Rep responsible for VIM5 induction remain poorly characterized. Although Rep proteins from several geminiviruses act as viral suppressors of RNA silencing (VSRs), whether BSCTV Rep also possesses VSR activity remains to be illustrated. In this study, we employed a transient expression system in the 16c-GFP transgenic and the wild-type Nicotiana benthamiana plants to analyze the VSR and the VIM5-inducing activities of different truncated Rep proteins haboring distinct domains. We found that the N-terminal domain (amino acids 1-180) of Rep suppressed GFP silencing in 16c-GFP transgenic N. benthamiana leaves. The minimal N-terminal fragment (amino acids 1-104) induced VIM5 expression upon co-infiltration, while C-terminal truncations lacked VIM5-inducing activity. Our results indicate that the N-terminal domain of Rep encoded by BSCTV mediates the suppression of RNA silencing and induces VIM5 expression. Thus, our findings contribute to a better understanding of interactions between geminiviral Rep and plant hosts.
Geminiviridae/genetics* ; Nicotiana/metabolism* ; Arabidopsis/metabolism* ; RNA Interference ; Viral Proteins/metabolism* ; Arabidopsis Proteins/metabolism* ; Plants, Genetically Modified/metabolism* ; Protein Domains ; Plant Diseases/virology* ; Methyltransferases/metabolism* ; Ubiquitin-Protein Ligases/metabolism* ; DNA Helicases/genetics*

OBJECTIVE: To analyze the clinical phenotype and genetic basis of four children with CHARGE syndrome. METHODS: A retrospective analysis was conducted on four children diagnosed with CHARGE syndrome at Xiamen Children's Hospital from May 2019 to May 2025. Peripheral venous blood samples were collected from the children and their parents and subjected to trio-whole exome sequencing. Candidate variants were verified by Sanger sequencing. Online tools were used for the conservation analysis and protein structure prediction. This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: 2024-126). RESULTS: The four children have included two neonates, one infant and one child, with their age at the initial diagnosis ranging from 16 days after birth to 11 years old. Their initial manifestations were not typical of CHARGE syndrome. All children were found to harbor missense variants of the CHD7 gene, including c.3059T>C (p.L1020S), c.3302G>A (p.C1101Y), c.5879C>T (p.S1960F) and c.8093C>T (p.S2698L). Sanger sequencing confirmed that two were de novo variants, and two were inherited from their parents. In child 1, the leucine at position 1020 was highly conserved, and the p.L1020S variant did not alter the spatial structure and hydrogen bond connections of the CHD7 protein, though the shape of the binding cavity and the number and distribution of binding probe clusters have changed. In child 4, an unreported variant in the epilepsy gene SCN9A (c.2152T>C, p.Y718H) was detected, along with bilateral lower limb deformities. Literature review suggested that missense variants of the CHD7 gene were most common (32.1%) among the Chinese population, whilst nonsense variants had the highest lethality rate (41.2%) in neonates. CONCLUSION Variants of the CHD7 gene probably underlay the pathogenesis in the four children. Changes in the binding sites and binding cavity morphology play an important role in CHARGE syndrome. The types of genetic variants in CHARGE patients may vary between different regions and races.
Humans ; CHARGE Syndrome/genetics* ; Male ; Female ; Child ; Infant ; Infant, Newborn ; DNA Helicases/genetics* ; DNA-Binding Proteins/chemistry* ; Mutation, Missense ; Retrospective Studies ; Child, Preschool ; Exome Sequencing ; Phenotype

Porcine deltacoronavirus (PDCoV) is a major pathogen causing fatal diarrhea in suckling piglets, and there is currently a lack of effective vaccines and drugs to prevent and control the virus. The nonstructural protein 13 (NSP13) serves as a virus-coded helicase and is considered to be a crucial target for antiviral drugs, making it imperative to investigate the helicase activity of NSP13. In this study, the NSP13 gene of PDCoV was synthesized and integrated into the prokaryotic expression vector pET-28a to construct the recombinant plasmid pET-28a-NSP13. NSP13 was successfully expressed in BL21 (DE3) and subsequently purified. The study also verified the helicase activity of the purified NSP13 and explored the factors that influence this activity. The results indicated that NSP13 from PDCoV was effectively expressed in the prokaryotic system and exhibited helicase activity, capable of unwinding double-stranded DNA with a tail at the 5' end. Additionally, NSP13 demonstrated an annealing function by promoting the complementary pairing of single-stranded nucleotide chains to form double strands. The helicase activity of NSP13 was affected by metal ions, but Mg²⁺concentrations in the range of 0.5-6.0 mmol/L had no significant effect on helicase activity of NSP13. When the solution pH was in the range of 4-9, there was no difference in helicase activity. ATP concentrations in the range of 0.25-6.00 mmol/L had a weak effect on helicase activity, and NSP13 concentration ≥80 nmol/L inhibited the helicase activity. We obtained the NSP13 of PDCoV and investigated its helicase activity. These findings provided a theoretical foundation for the further research on the regulatory mechanism of NSP13 in PDCoV replication and the development of anti-coronaviral drugs.
Viral Nonstructural Proteins/metabolism* ; Escherichia coli/metabolism* ; Recombinant Proteins/metabolism* ; Swine ; Animals ; DNA Helicases/metabolism* ; Genetic Vectors/metabolism*

Objective: To investigate the clinicopathological features and immunohistochemical phenotypes of gastric SMARCA4-deficient undifferentiated carcinoma, and to discuss the daily diagnostics of this entity and analyze its prognosis. Methods: The cases of gastric SMARCA4-deficient undifferentiated carcinoma diagnosed at the Department of Pathology, Peking University Cancer Hospital, China from January 2010 to August 2022 were collected. The histological sections were reviewed, the immunohistochemical results and clinicopathological features were analyzed, and relevant literature was reviewed. Results: Pure foci of undifferentiated carcinoma were seen in 7 cases, and 1 case was accompanied by a moderately differentiated tubular adenocarcinoma component. Undifferentiated carcinoma foci showed similar sheet-like or solid diffuse growth pattern, medium-sized tumor cells characterized by 1-2 nucleoli, and abundant cytoplasm and rhabdoid appearance. The average patient age was 65±8 years. Six patients were male and 2 were female. Immunohistochemical staining showed that undifferentiated carcinoma of all 8 tumors were negative for SMARCA4 (BRG1). Among 7 patients who underwent SMARCA2 (BRM) and SMARCB1 (INI1) staining, 4 cases showed loss of BRM expression, 2 cases showed weakly positive staining, and 1 case was diffusely positive, but all 7 cases were diffusely strong positive for INI1. The neuroendocrine marker, synaptophysin, was weakly positive in 5 cases, while CgA and CD56 were negative in 8 cases. Ki-67 index was more than 70%. Two cases were mismatch repair deficient and showed the loss of MLH1/PMS2 expression, while 1 case showed only MSH2 loss. PD-L1 staining showed that combined positive score (CPS)≥1 in 4 cases (CPS ranging from 1 to 55) and CPS<1 in the other 3 cases. Four patients had clinical stage Ⅳ disease. Two of them died within 3 months after diagnosis. Conclusions: Gastric SMARCA4-deficient undifferentiated carcinoma/rhabdoid carcinoma is a rare group of highly malignant tumors with a poor prognosis. Loss of the core subunit of SWI/SNF complex may be associated with the development of dedifferentiated histological pattern and aggressive tumor progression, which may be more frequently accompanied with mismatch repair deficiency.
Male ; Female ; Humans ; Carcinoma/pathology* ; Adenocarcinoma ; Colorectal Neoplasms ; Cell Differentiation ; Stomach Neoplasms ; Biomarkers, Tumor ; DNA Helicases ; Nuclear Proteins ; Transcription Factors

Objective: To investigate and elucidate the clinicopathological and prognostic characteristics of SMARCA4-deficient non-small cell lung cancer. Methods: The clinicopathological and prognostic data were collected in 127 patients with SMARCA4-deficient non-small cell lung cancer diagnosed in Shanghai Pulmonary Hospital, Shanghai, China from January 2020 to March 2022. The variation and expression of biomarkers related to treatment were retrospectively reviewed. Results: One hundred and twenty-seven patients were eligible for enrollment. Among them 120 patients (94.5%) were male and 7 cases (5.5%) were female, while the average age was 63 years (range 42-80 years). There were 41 cases (32.3%) of stage Ⅰ cancer, 23 cases (18.1%) of stage Ⅱ, 31 cases (24.4%) of stage Ⅲ and 32 cases (25.2%) of stage Ⅳ. SMARCA4 expression detected by immunohistochemistry was completely absent in 117 cases (92.1%) and partially absent in 10 cases (7.9%). PD-L1 immunohistochemical analyses were performed on 107 cases. PD-L1 was negative, weakly positive and strongly positive in 49.5% (53/107), 26.2% (28/107) and 24.3% (26/107) of the cases, respectively. Twenty-one cases showed gene alterations (21/104, 20.2%). The KRAS gene alternation (n=10) was most common. Mutant-type SMARCA4-deficient non-small cell lung cancer was more commonly detected in females, and was associated with positive lymph nodes and advanced clinical stage (P<0.01). Univariate survival analysis showed that advanced clinical stage was a poor prognosis factor, and vascular invasion was a poor predictor of progression-free survival in patients with surgical resection. Conclusions: SMARCA4-deficient non-small cell lung cancer is a rare tumor with poor prognosis, and often occurs in elderly male patients. However, SMARCA4-deficient non-small cell lung cancers with gene mutations are often seen in female patients. Vascular invasion is a prognostic factor for disease progression or recurrence in patients with resectable tumor. Early detection and access to treatment are important for improving patient survivals.
Humans ; Male ; Female ; Aged ; Adult ; Middle Aged ; Aged, 80 and over ; Carcinoma, Non-Small-Cell Lung/pathology* ; B7-H1 Antigen/metabolism* ; Lung Neoplasms/pathology* ; Retrospective Studies ; China ; Prognosis ; Biomarkers, Tumor/analysis* ; DNA Helicases/genetics* ; Nuclear Proteins/genetics* ; Transcription Factors/genetics*

BACKGROUND: Juvenile amyotrophic lateral sclerosis (JALS) is an uncommon form of amyotrophic lateral sclerosis whose age at onset (AAO) is defined as prior to 25 years. FUS mutations are the most common cause of JALS. SPTLC1 was recently identified as a disease-causative gene for JALS, which has rarely been reported in Asian populations. Little is known regarding the difference in clinical features between JALS patients carrying FUS and SPTLC1 mutations. This study aimed to screen mutations in JALS patients and to compare the clinical features between JALS patients with FUS and SPTLC1 mutations. METHODS: Sixteen JALS patients were enrolled, including three newly recruited patients between July 2015 and August 2018 from the Second Affiliated Hospital, Zhejiang University School of Medicine. Mutations were screened by whole-exome sequencing. In addition, clinical features such as AAO, onset site and disease duration were extracted and compared between JALS patients carrying FUS and SPTLC1 mutations through a literature review. RESULTS: A novel and de novo SPTLC1 mutation (c.58G>A, p.A20T) was identified in a sporadic patient. Among 16 JALS patients, 7/16 carried FUS mutations and 5/16 carried respective SPTLC1 , SETX , NEFH , DCTN1 , and TARDBP mutations. Compared with FUS mutation patients, those with SPTLC1 mutations had an earlier AAO (7.9 ± 4.6 years vs. 18.1 ± 3.9 years, P  < 0.01), much longer disease duration (512.0 [416.7-607.3] months vs. 33.4 [21.6-45.1] months, P  < 0.01), and no onset of bulbar. CONCLUSION Our findings expand the genetic and phenotypic spectrum of JALS and help to better understand the genotype-phenotype correlation of JALS.
Humans ; Amyotrophic Lateral Sclerosis/genetics* ; DNA Helicases/genetics* ; Genetic Association Studies ; Multifunctional Enzymes/genetics* ; Mutation/genetics* ; RNA Helicases/genetics* ; RNA-Binding Protein FUS/genetics* ; Serine C-Palmitoyltransferase/genetics* ; Child, Preschool ; Child ; Adolescent ; Young Adult

Humans ; Biopsy, Fine-Needle ; Carcinoma/pathology* ; Esophagogastric Junction/pathology* ; Cytodiagnosis ; DNA Helicases ; Nuclear Proteins ; Transcription Factors

Chromodomain-helicase-DNA-binding protein 1 (CHD1) deletion is among the most common mutations in prostate cancer (PCa), but its role remains unclear. In this study, RNA sequencing was conducted in PCa cells after clustered regularly interspaced palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9)-based CHD1 knockout. Gene set enrichment analysis (GSEA) indicated upregulation of hypoxia-related pathways. A subsequent study confirmed that CHD1 deletion significantly upregulated hypoxia-inducible factor 1α (HIF1α) expression. Mechanistic investigation revealed that CHD1 deletion upregulated HIF1α by transcriptionally downregulating prolyl hydroxylase domain protein 2 (PHD2), a prolyl hydroxylase catalyzing the hydroxylation of HIF1α and thus promoting its degradation by the E3 ligase von Hippel-Lindau tumor suppressor (VHL). Functional analysis showed that CHD1 deletion promoted angiogenesis and glycolysis, possibly through HIF1α target genes. Taken together, these findings indicate that CHD1 deletion enhances HIF1α expression through PHD2 downregulation and therefore promotes angiogenesis and metabolic reprogramming in PCa.
Male ; Humans ; Von Hippel-Lindau Tumor Suppressor Protein/metabolism* ; DNA-Binding Proteins/metabolism* ; Prolyl Hydroxylases/metabolism* ; Hypoxia ; Prostatic Neoplasms/pathology* ; Glycolysis ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Cell Line, Tumor ; DNA Helicases/metabolism*