The doublecortin (DCX) gene encodes DCX, a microtubule-associated protein that plays a crucial role in brain development. DCX variants can disrupt microtubule binding and stabilization, interfere with intracellular transport, and affect post-translational modifications. A correlation exists between variant types and clinical severity. Animal models and induced pluripotent stem cell (iPSC) models simulating DCX deficiency revealed the dynamic progression of the disease, which has provided a powerful tool for investigating disease mechanisms and screening therapeutic agents. Currently there is no cure for DCX variants, with treatment primarily relying on anti-epileptic drugs and symptom management. Basic research is now offering new avenues for future therapeutic approaches. This article has summarized the potential pathogenic mechanisms and therapeutic strategies for the DCX variants, with an aim to provide insights for clinical treatment.
Humans ; Doublecortin Protein ; Doublecortin Domain Proteins ; Animals ; Neuropeptides/metabolism* ; Microtubule-Associated Proteins/metabolism* ; Mutation

OBJECTIVE: To analyze the clinical characteristics, treatment, and prognosis of seven pediatric patients with Acute myeloid leukemia (AML) positive for the t(16;21)(p11;q22) FUS::ERG fusion gene. METHODS: A retrospective analysis was carried out on the clinical data, treatment, and prognosis of seven AML patients with t(16;21)(p11;q22) FUS::ERG fusion gene admitted to Henan Children's Hospital between June 2015 and November 2024. Relevant literature was also reviewed. This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: 2024-102-001). RESULTS: Among 297 pediatric patients with AML, 7 cases (2.36%) were positive for the t(16;21)(p11;q22) FUS::ERG fusion gene, including 3 males and 4 females, with a median age of 11 years (range: 3 ~ 12 years). According to the FAB classification, these included 1 case of M2, 3 cases of M5, and 3 cases of AML-not otherwise specified (non-M3). All 7 patients were found to harbor the t(16;21)(p11;q22) translocation, with 3 cases showing additional chromosomal abnormalities. Immunophenotyping revealed universal expression of CD13, CD33, CD34, and CD117, with partial expression of CD56, CD4, CD64, CD123, CD15, CD38, CD11b, HLA-DR, cMPO, and CD16. One patient achieved complete remission (CR) after the first course of DAE (cytarabine + daunorubicin + etoposide) induction chemotherapy but relapsed and discontinued the treatment. Six patients received DAH (cytarabine + daunorubicin + homoharringtonine) induction therapy, of whom 2 achieved CR after two courses and underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT), resulting in an overall CR rate of 42.86%. Five children did not receive allo-HSCT and had a median overall survival of 9 months (range: 6 ~ 18 months). Two children who underwent transplantation achieved bone marrow morphological and molecular biological relapse at 6 and 9 months post-transplantation, respectively. After receiving combined chemotherapy and donor lymphocyte infusion, one child failed to achieve remission and died at 22 months post-transplantation, while the other has been followed up to date with positive fusion gene status. Their overall survival was 25 months and 30 months, respectively. CONCLUSION The t(16;21)(p11;q22) FUS::ERG fusion gene is rare in pediatric AML and associated with poor prognosis. Allo-HSCT may mitigate the adverse prognostic impact of the FUS::ERG fusion gene and contribute to prolonged survival.
Humans ; Male ; Child ; Female ; Leukemia, Myeloid, Acute/drug therapy* ; Oncogene Proteins, Fusion/genetics* ; Translocation, Genetic ; Retrospective Studies ; RNA-Binding Protein FUS/genetics* ; Chromosomes, Human, Pair 16/genetics* ; Adolescent ; Child, Preschool ; Chromosomes, Human, Pair 21/genetics* ; Prognosis ; Treatment Outcome

OBJECTIVE: To explore the genetic basis for a Chinese pedigree affected with Hereditary spastic paraplegia type 3A (SPG3A) and the genotype-phenotype correlation. METHODS: A three-generation pedigree presented at Huantai Maternal and Child Health Care Hospital in March 2021 was selected as the study subject. Whole-exome sequencing (WES) and pedigree analysis was carried out. Candidate variant was validated by Sanger sequencing of the members from the pedigree. Haplotype analysis was used to trace the origin of the variant, and pathogenicity was rated based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: 2025-12). RESULTS: A c.1024C>T (p.Pro342Ser) variant of the ATL1 was identified in the four affected members, including the proband, but none of the three unaffected relatives. Haplotype analysis suggested that the variant was derived from the proband's mother and has co-segregated with the disease phenotype. Based on the guidelines of the ACMG, it was classified as likely pathogenic. CONCLUSION The ATL1 c.1024C>T (p.Pro342Ser) variant probably underlay the pathogenesis in this pedigree. Above finding has enriched the mutational spectrum of ATL1 and phenotypic spectrum of SPG3A in the Chinese population, and enabled genetic counseling for this pedigree.
Humans ; Pedigree ; Spastic Paraplegia, Hereditary/genetics* ; Male ; Female ; Asian People/genetics* ; Adult ; Haplotypes ; Membrane Proteins/genetics* ; Exome Sequencing ; GTP-Binding Proteins/genetics* ; Mutation ; Middle Aged ; China ; Genetic Association Studies ; East Asian People

OBJECTIVE: To delineate the clinical and genetic features of a Chinese girl harboring a rare de novo variant of SYNGAP1 associated with Mental retardation, autosomal dominant 5 (MRD5), and to conduct a comprehensive genotype-phenotype correlation analysis within the Chinese population through an extensive literature review. METHODS: A 5-year-old girl presenting with seizures without an obvious cause was enrolled in September 2020. Genomic DNA was extracted from the patient and her parents. Whole exome sequencing (WES) was performed on the proband to identify suspected pathogenic variants based on her clinical phenotype. Sanger sequencing was used for validation, followed by bioinformatic analysis of the variant. Additionally, data from 54 previously reported Chinese cases with SYNGAP1 variants were integrated to summarize the distribution of variant types and clinical characteristics. Ethical approval was obtained from the Ethics Committee of Kunming Children's Hospital (Ethics No.: 2021-03-055-K01). RESULTS: WES identified a heterozygous nonsense variant, SYNGAP1 c.725G>A (p.Trp242*), in the proband. Sanger sequencing confirmed it was a de novo variant. According to the ACMG guidelines, this variant was classified as pathogenic (PVS1+PS2). Based on the clinical manifestations, the patient was diagnosed with MRD5. Bioinformatic analysis suggested that this variant introduces a premature stop codon at tryptophan 242, disrupting the PH domain and leading to the loss of the C2, Ras-GAP, and C-terminal domains. The pooled analysis of Chinese cases revealed that nonsense (38.2%) and frameshift (36.4%) variants were the predominant types. Intellectual disability/developmental delay was present in 100.0% of patients, epilepsy in 83.6%, and autism spectrum disorder in 41.3%. The incidence of epilepsy differed significantly among variant types (P = 0.045). Exons 8 and 15 were identified as mutation hotspots. CONCLUSION This study has identified a SYNGAP1 c.725G>A variant in the Chinese population and confirmed it as a potential cause of MRD5, which expanded the mutational spectrum of this disorder.
Humans ; Female ; Child, Preschool ; Intellectual Disability/genetics* ; ras GTPase-Activating Proteins/genetics* ; Phenotype ; Exome Sequencing ; Genetic Association Studies

OBJECTIVE: To analyze the clinical characteristics of patients with 11q23 rearrangement acute lymphoblastic leukemia (ALL) with non-KMT2A::AFF1 fusion genes. METHODS: The clinical data of 10 patients with KMT2A fusion gene positive and partner gene non-AFF1 ALL admitted to Henan Cancer Hospital from December 2016 to December 2024 were retrospectively summarized. The immunophenotype, molecular genetic characteristics, clinical manifestations and disease prognosis of these patients were analyzed. This research has been approved by the Medical Ethics Committee of Henan Cancer Hospital (Ethics No.: 2019342). RESULTS: Among the 10 patients, the fusion genes were KMT2A::MLLT1 in 7 cases, KMT2A::MLLT4, KMT2A::MLLT3 and KMT2A::MLLT10 in 1 case each. The European Group for the Immunological Classification of Leukemias (EGIL) classification included 6 cases of T-ALL, 2 cases of pro-B-ALL, 1 case of Common-B-ALL and 1 case of pre-B-ALL. 4 cases of B-ALL all expressed CD19, cCD79a, CD38 and HLA-DR, and some expressed CD34 and CD22, without expression or weak expression of CD10, without expression of CD20. One case was accompanied by myeloid marker CD15 expression. 6 cases of T-ALL all expressed CD34, CD7, most expressed CD38, and some expressed CD3, CD5, CD2, CD4 and CD8, and 1 case expressed CD4 and CD8 together. Chromosomal abnormalities were detected in 3 cases, 5 cases were positive for WT1 fusion gene, and 6 cases had gene alterations. 9 patients achieved the first complete remission (CR1) during chemotherapy, and 1 patient relapsed within 6 months after CR1. At the last follow up, 1 patient (the fusion gene was KMT2A::MLLT4) remained unrelieved. There were 2 cases of KMT2A rearrangement (KMT2A-r) persistent positive (+/+) and 8 cases of KMT2A-r negative (+/-). The overall survival (OS) rate and leukemia-free survival (LFS) rate of patients with KMT2A-r persistent positive were significantly lower than those of patients with negative change, and the differences were statistically significant (P values were all < 0.05). Among the 3 patients who received chemotherapy+allogeneic hematopoietic stem cell transplantation (allo-HSCT), no relapse was observed until the follow up day. The OS rate and LFS rate of patients with KMT2A::MLLT1 and chemotherapy+allo-HSCT were higher than those of non-KMT2A::MLLT1 and single chemotherapy patients, and the differences were not statistically significant (P values were all ≥ 0.05). There was no significant difference in OS rate and LFS rate between T-ALL and B-ALL patients (P values were all ≥ 0.05). The median LFS time of the 10 patients was 32 (0 ~ 100) months, and the median OS time was 36 (1 ~ 101) months. CONCLUSION The 11q23 rearrangement ALL with non-KMT2A::AFF1 transcript is mainly KMT2A::MLLT1, T-ALL is more common, and the rate of chromosomal karyotype detection is relatively low. Persistent positive KMT2A-r is unfavorable for patient survival, and allo-HSCT during the CR1 period may improve patient survival.
Humans ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics* ; Female ; Male ; Myeloid-Lymphoid Leukemia Protein/genetics* ; Histone-Lysine N-Methyltransferase/genetics* ; Adult ; Adolescent ; Chromosomes, Human, Pair 11/genetics* ; Child ; Transcriptional Elongation Factors/genetics* ; Gene Rearrangement ; Oncogene Proteins, Fusion/genetics* ; Retrospective Studies ; Young Adult ; Middle Aged ; Prognosis ; Child, Preschool ; DNA-Binding Proteins/genetics*

Endosomes are characterized by the presence of various phosphoinositides that are essential for defining the membrane properties. However, the interplay between endosomal phosphoinositides metabolism and innate immunity is yet to be fully understood. Here, our findings highlight the evolutionary continuity of RAB-10/Rab10's involvement in regulating innate immunity. Upon infection of Caenorhabditis elegans with Pseudomonas aeruginosa, an increase in RAB-10 activity was observed in the intestine. Conversely, when RAB-10 was absent, the intestinal diacylglycerols (DAGs) decreased, and the animal's response to the pathogen was impaired. Further research revealed that UNC-16/JIP3 acts as an RAB-10 effector, facilitating the recruitment of phospholipase EGL-8 to endosomes. This leads to a decrease in endosomal phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and an elevation of DAGs, as well as the activation of the PMK-1/p38 MAPK innate immune pathway. It is noteworthy that the dimerization of UNC-16 is a prerequisite for its interaction with RAB-10(GTP) and the recruitment of EGL-8. Moreover, we ascertained that the rise in RAB-10 activity, due to infection, was attributed to the augmented expression of LET-413/Erbin, and the nuclear receptor NHR-25/NR5A1/2 was determined to be indispensable for this increase. Hence, this study illuminates the significance of endosomal PI(4,5)P2 catabolism in boosting innate immunity and outlines an NHR-25-mediated mechanism for pathogen detection in intestinal epithelia.
Animals ; Caenorhabditis elegans/genetics* ; Endosomes/immunology* ; Caenorhabditis elegans Proteins/immunology* ; Phosphatidylinositol 4,5-Diphosphate/immunology* ; Immunity, Innate ; Pseudomonas aeruginosa/immunology* ; rab GTP-Binding Proteins/genetics* ; Diglycerides/metabolism*

Pyroptosis is an identified programmed cell death that has been highly linked to endoplasmic reticulum (ER) dynamics. However, the crucial proteins for modulating dynamic ER membrane curvature change that trigger pyroptosis are currently not well understood. In this study, a biotin-labeled chemical probe of potent pyroptosis inducer α-mangostin (α-MG) was synthesized. Through protein microarray analysis, reticulon-4 (RTN4/Nogo), a crucial regulator of ER membrane curvature, was identified as a target of α-MG. We observed that chemically induced proteasome degradation of RTN4 by α-MG through recruiting E3 ligase UBR5 significantly enhances the pyroptosis phenotype in cancer cells. Interestingly, the downregulation of RTN4 expression significantly facilitated a dynamic remodeling of ER membrane curvature through a transition from tubules to sheets, consequently leading to rapid fusion of the ER with the cell plasma membrane. In particular, the ER-to-plasma membrane fusion process is supported by the observed translocation of several crucial ER markers to the "bubble" structures of pyroptotic cells. Furthermore, α-MG-induced RTN4 knockdown leads to pyruvate kinase M2 (PKM2)-dependent conventional caspase-3/gasdermin E (GSDME) cleavages for pyroptosis progression. In vivo, we observed that chemical or genetic RTN4 knockdown significantly inhibited cancer cells growth, which further exhibited an antitumor immune response with anti-programmed death-1 (anti-PD-1). In translational research, RTN4 high expression was closely correlated with the tumor metastasis and death of patients. Taken together, RTN4 plays a fundamental role in inducing pyroptosis through the modulation of ER membrane curvature remodeling, thus representing a prospective druggable target for anticancer immunotherapy.
Pyroptosis/immunology* ; Humans ; Endoplasmic Reticulum/immunology* ; Animals ; Nogo Proteins/antagonists & inhibitors* ; Mice ; Cell Line, Tumor ; Xanthones/pharmacology* ; Neoplasms/pathology* ; Mice, Nude

Nipah virus (NiV) and related viruses form a distinct henipavirus genus within the Paramyxoviridae family. NiV continues to spillover into the humans causing deadly outbreaks with increasing human-bat interaction. NiV encodes the large protein (L) and phosphoprotein (P) to form the viral RNA polymerase machinery. Their sequences show limited homologies to those of non-henipavirus paramyxoviruses. We report two cryo-electron microscopy (cryo-EM) structures of the Nipah virus (NiV) polymerase L-P complex, expressed and purified in either its full-length or truncated form. The structures resolve the RNA-dependent RNA polymerase (RdRp) and polyribonucleotidyl transferase (PRNTase) domains of the L protein, as well as a tetrameric P protein bundle bound to the L-RdRp domain. L-protein C-terminal regions are unresolved, indicating flexibility. Two PRNTase domain zinc-binding sites, conserved in most Mononegavirales, are confirmed essential for NiV polymerase activity. The structures further reveal anchoring of the P protein bundle and P protein X domain (XD) linkers on L, via an interaction pattern distinct among Paramyxoviridae. These interactions facilitate binding of a P protein XD linker in the nucleotide entry channel and distinct positioning of other XD linkers. We show that the disruption of the L-P interactions reduces NiV polymerase activity. The reported structures should facilitate rational antiviral-drug discovery and provide a guide for the functional study of NiV polymerase.
Nipah Virus/chemistry* ; Cryoelectron Microscopy ; Viral Proteins/genetics* ; RNA-Dependent RNA Polymerase/genetics* ; Phosphoproteins/genetics* ; Humans ; Models, Molecular ; Protein Binding

Protein liquid-liquid phase separation (LLPS), a pivotal phenomenon intricately linked to cellular processes, is regulated by various other proteins. However, there is still a lack of high-throughput methods for screening protein regulators of LLPS in target proteins. Here, we developed a CRISPR/Cas9-based screening method to identify protein phase separation regulators by integrating bimolecular fluorescence complementation (BiFC) and fluorescence-activated cell sorting (FACS). Using this newly developed method, we screened the RNA-binding proteins that regulate PABPN1 phase separation and identified the tumor suppressor QKI as a promoter of PABPN1 phase separation. Furthermore, QKI exhibits decreased expression levels and diminished nuclear localization in colorectal cancer cells, resulting in reduced PABPN1 phase separation, which, in turn, promotes alternative polyadenylation (APA), cell proliferation, and migration in colorectal cancer.
Humans ; Colorectal Neoplasms/genetics* ; RNA-Binding Proteins/genetics* ; Poly(A)-Binding Protein I/genetics* ; CRISPR-Cas Systems ; Flow Cytometry ; Cell Proliferation ; Cell Line, Tumor ; Cell Movement

Glutamine provides carbon and nitrogen to support the proliferation of cancer cells. However, the precise reason why cancer cells are particularly dependent on glutamine remains unclear. In this study, we report that glutamine modulates the tumor suppressor F-box and WD repeat domain-containing 7 (FBW7) to promote cancer cell proliferation and survival. Specifically, lysine 604 (K604) in the sixth of the 7 substrate-recruiting WD repeats of FBW7 undergoes glutaminylation (Gln-K604) by glutaminyl tRNA synthetase. Gln-K604 inhibits SCFFBW7-mediated degradation of c-Myc and Mcl-1, enhances glutamine utilization, and stimulates nucleotide and DNA biosynthesis through the activation of c-Myc. Additionally, Gln-K604 promotes resistance to apoptosis by activating Mcl-1. In contrast, SIRT1 deglutaminylates Gln-K604, thereby reversing its effects. Cancer cells lacking Gln-K604 exhibit overexpression of c-Myc and Mcl-1 and display resistance to chemotherapy-induced apoptosis. Silencing both c-MYC and MCL-1 in these cells sensitizes them to chemotherapy. These findings indicate that the glutamine-mediated signal via Gln-K604 is a key driver of cancer progression and suggest potential strategies for targeted cancer therapies based on varying Gln-K604 status.
Glutamine/metabolism* ; Myeloid Cell Leukemia Sequence 1 Protein/genetics* ; Humans ; Proto-Oncogene Proteins c-myc/genetics* ; Cell Proliferation ; Signal Transduction ; Neoplasms/pathology* ; F-Box-WD Repeat-Containing Protein 7/genetics* ; Cell Survival ; Cell Line, Tumor ; Apoptosis