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

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*

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 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*

Endometrial cancer is the most common gynecological malignancy, affecting up to 3% of women at some point during their lifetime (Morice et al., 2016; Li and Wang, 2021). Based on the pathogenesis and biological behavioral characteristics, endometrial cancer can be divided into estrogen-dependent (I) and non-estrogen-dependent (II) types (Ulrich, 2011). Type I accounts for approximately 80% of cases, of which the majority are endometrioid carcinomas, and the remaining are mucinous adenocarcinomas (Setiawan et al., 2013). It is generally recognized that long-term stimulation by high estrogen levels with the lack of progesterone antagonism is the most important risk factor; meanwhile, there is no definite conclusion on the specific pathogenesis. The incidence of endometrial cancer has been on the rise during the past two decades (Constantine et al., 2019; Gao et al., 2022; Luo et al., 2022). Moreover, the development of assisted reproductive technology and antiprogestin therapy following breast cancer surgery has elevated the risk of developing type I endometrial cancer to a certain extent (Vassard et al., 2019). Therefore, investigating the influence of estrogen in type I endometrial cancer may provide novel concepts for risk assessment and adjuvant therapy, and at the same time, provide a basis for research on new drugs to treat endometrial cancer.
Female ; Humans ; Proto-Oncogene Proteins c-akt ; Phosphatidylinositol 3-Kinases ; Endometrial Neoplasms ; Estrogens ; Breast Neoplasms ; DNA Helicases

We explored clinicopathological features and treatment strategies for thoracic SMARCA4-deficient undifferentiated tumor (SMARCA4-UT). Thoracic SMARCA4-UT is a new entity recently acknowledged in the 2021 edition of World Health Organization Classification of Thoracic Tumors, and doctors are relatively unfamiliar with its diagnosis, treatment, and prognosis. Taking a case of SMARCA4-UT treated in Peking University First Hospital as an example, this multi-disciplinary discussion covered several hot issues on diagnosing and treating thoracic SMARCA4-UT, including histological features, immu- nohistochemical and molecular phenotype, immune checkpoint inhibitor (ICI) therapy, and pathological assessment of neoadjuvant therapy response. The patient was an older man with a long history of smoking and was admitted due to a rapidly progressing solid tumor in the lower lobe of the right lung. Histologically, tumor cells were epithelioid, undifferentiated, diffusely positive for CD34, and partially positive for SALL4.The expression of BRG1 protein encoded by SMARCA4 gene was lost in all of tumor cells, and next-generation sequencing(NGS)confirmed SMARCA4 gene mutation (c.2196T>G, p.Y732Ter). The pathological diagnosis reached as thoracic SMARCA4-UT, and the preoperative TNM stage was T1N2M0 (ⅢA). Tumor proportion score (TPS) detected by immunohistochemistry of programmed cell death 1-ligand 1 (PD-L1, clone SP263) was 2%. Tumor mutation burden (TMB) detected by NGS of 1 021 genes was 16. 3/Mb. Microsatellite detection showed the tumor was microsatellite stable (MSS). Neo-adjuvant therapy was implemented with the combined regimen of chemotherapy and ICI. Right lower lobectomy was performed through thoracoscopy after the two weeks' neoadjuvant. The pathologic assessment of lung tumor specimens after neoadjuvant therapy revealed a complete pathological response (CPR). The post-neoadjuvant tumor TNM stage was ypT0N0M0. Then, five cycles of adjuvant therapy were completed. Until October 2022, neither tumor recurrence nor metastasis was detected, and minimal residual disease (MRD) detection was negative. At present, it is believed that if BRG1 immunohistochemical staining is negative, regardless of whether SMARCA4 gene mutation is detected, it should be classified as SMARCA4-deficient tumors. SMARCA4-deficient tumors include a variety of carcinomas and sarcomas. The essential criteria for diagnosing SMARCA4-UT includes loss of BRG1 expression, speci-fic histological morphology, and exclude other common thoracic malignant tumors with SMARCA4-deficiency, such as squamous cell carcinoma, adenocarcinoma and large cell carcinoma. SMARCA4-UT is a very aggressive malignant tumor with a poor prognosis. It has almost no targeted therapy mutations, and little response to chemotherapy, but ICI is currently the only effective drug. The successful diagnosis and treatment for this case of SMARCA4-UT should enlighten significance for various kinds of SMARCA4-deficient tumors.
Humans ; Immune Checkpoint Inhibitors ; Neoplasm Recurrence, Local ; Lung Neoplasms/genetics* ; Thoracic Neoplasms/pathology* ; Adenocarcinoma ; DNA Helicases ; Nuclear Proteins ; Transcription Factors

OBJECTIVE: To explore the clinical feature and genetic etiology of a patient with normosmic idiopathic hypogonadotropic hypogonadism (nIHH) due to variant of CHD7 gene. METHODS: A patient who had presented at Anhui Provincial Children's Hospital in October 2022 was selected as the study subject. Clinical data of the patient was collected. The patient and his parents were subjected to trio-whole exome sequencing. Candidate variant was verified by Sanger sequencing and bioinformatic analysis. RESULTS: The patient had featured delayed development of secondary sexual characteristics but normal olfactory function. Genetic testing revealed that he has harbored a c.3052C>T (p.Pro1018Ser) missense variant of the CHD7 gene, for which both of his parents were of the wild type. The variant has not been recorded in the PubMed and HGMD databases. Analysis of amino acid sequences suggested that the variant site is highly conserved, and the variant may affect the stability of protein structure. Based on the guidelines from the American College of Medical Genetics and Genomics, the c.3032C>T variant was classified as a likely pathogenic (PS2+PM2_Supporting+PP2+PP3+PP4). CONCLUSION The delayed development of secondary sexual characteristics of the patient may be attributed to the c.3052C>T (p.Pro1018Ser) variant of the CHD7 gene. Above finding has expanded the variation spectrum of the CHD7 gene.
Child ; Humans ; Male ; Amino Acid Sequence ; Computational Biology ; DNA Helicases/genetics* ; DNA-Binding Proteins/genetics* ; Genetic Testing ; Genomics ; Hypogonadism/genetics* ; Mutation

The cranial neural crest plays a fundamental role in orofacial development and morphogenesis. Accordingly, mutations with impact on the cranial neural crest and its development lead to orofacial malformations such as cleft lip and palate. As a pluripotent and dynamic cell population, the cranial neural crest undergoes vast transcriptional and epigenomic alterations throughout the formation of facial structures pointing to an essential role of factors regulating chromatin state or transcription levels. Using CRISPR/Cas9-guided genome editing and conditional mutagenesis in the mouse, we here show that inactivation of Kat5 or Ep400 as the two essential enzymatic subunits of the Tip60/Ep400 chromatin remodeling complex severely affects carbohydrate and amino acid metabolism in cranial neural crest cells. The resulting decrease in protein synthesis, proliferation and survival leads to a drastic reduction of cranial neural crest cells early in fetal development and a loss of most facial structures in the absence of either protein. Following heterozygous loss of Kat5 in neural crest cells palatogenesis was impaired. These findings point to a decisive role of the Tip60/Ep400 chromatin remodeling complex in facial morphogenesis and lead us to conclude that the orofacial clefting observed in patients with heterozygous KAT5 missense mutations is at least in part due to disturbances in the cranial neural crest.
Animals ; Mice ; Chromatin Assembly and Disassembly ; Cleft Lip/genetics* ; Cleft Palate/genetics* ; DNA Helicases/metabolism* ; DNA-Binding Proteins ; Neural Crest/metabolism* ; Skull ; Transcription Factors/metabolism*