T7 RNA polymerase (T7 RNAP) is one of the simplest known RNA polymerases. Its unique structural features make it a critical model for studying the mechanisms of RNA synthesis. This review systematically examines the static crystal structure of T7 RNAP, beginning with an in-depth examination of its characteristic “thumb”, “palm”, and “finger” domains, which form the classic “right-hand-like” architecture. By detailing these structural elements, this review establishes a foundation for understanding the overall organization of T7 RNAP. This review systematically maps the functional roles of secondary structural elements and their subdomains in transcriptional catalysis, progressively elucidating the fundamental relationships between structure and function. Further, the intrinsic flexibility of T7 RNAP and its applications in research are also discussed. Additionally, the review presents the structural diagrams of the enzyme at different stages of the transcription process, and through these diagrams, it provides a detailed description of the complete transcription process of T7 RNAP. By integrating structural dynamics and kinetics analyses, the review constructs a comprehensive framework that bridges static structure to dynamic processes. Despite its advantages, T7 RNAP has a notable limitation: it generates double-stranded RNA (dsRNA) as a byproduct. The presence of dsRNA not only compromises the purity of mRNA products but also elicits nonspecific immune responses, which pose significant challenges for biotechnological and therapeutic applications. The review provides a detailed exploration of the mechanisms underlying dsRNA formation during T7 RNAP catalysis, reviews current strategies to mitigate this issue, and highlights recent progress in the field. A key focus is the semi-rational design of T7 RNAP mutants engineered to minimize dsRNA generation and enhance catalytic performance. Beyond its role in transcription, T7 RNAP exhibits rapid development and extensive application in fields, including gene editing, biosensing, and mRNA vaccines. This review systematically examines the structure-function relationships of T7 RNAP, elucidates the mechanisms of dsRNA formation, and discusses engineering strategies to optimize its performance. It further explores the engineering optimization and functional expansion of T7 RNAP. Furthermore, this review also addresses the pressing issues that currently need resolution, discusses the major challenges in the practical application of T7 RNAP, and provides an outlook on potential future research directions. In summary, this review provides a comprehensive analysis of T7 RNAP, ranging from its structural architecture to cutting-edge applications. We systematically examine: (1) the characteristic right-hand domains (thumb, palm, fingers) that define its minimalistic structure; (2) the structure-function relationships underlying transcriptional catalysis; and (3) the dynamic transitions during the complete transcription cycle. While highlighting T7 RNAP’s versatility in gene editing, biosensing, and mRNA vaccine production, we critically address its major limitation—dsRNA byproduct formation—and evaluate engineering solutions including semi-rationally designed mutants. By synthesizing current knowledge and identifying key challenges, this work aims to provide novel insights for the development and application of T7 RNAP and to foster further thought and progress in related fields.

As a unique gene in the genome,FLASH(FADD-like interleukin-1β-converting enzyme asso-ciated huge protein)/CASP8AP2 is involved in multiple cellular processes,including apoptosis,histone gene pre-mRNA processing,transcriptional regulation,and cell cycle progression.Clinical studies have shown that FLASH is a valuable prognostic marker for acute lymphoblastic leukemia,and a crucial factor for the survival of various cancer cells.Therefore,in-depth research into the function of FLASH may offer new perspectives for the treatment of related diseases.Our previous research identified FLASH as a bind-ing partner of p53,demonstrating that FLASH enhances the transcriptional activity of p53.Here we fur-ther investigate the molecular mechanisms of the interaction between FLASH and p53,revealing that the p53-K386R mutation(SUMOylation residue)attenuated its interaction with FLASH(aa 51-200)and FLASH-SIM(SUMO-interacting motif)(aa 1 534-1 806)significantly.However,SUMO can bind to FLASH-SIM directly,instead of FLASH(aa 51-200).Subsequent research shows that overexpression of FLASH in cells enhances global SUMO1 conjugation and p53-SUMO1 conjugation,therefore providing a plausible explanation for the underlying mechanism of FLASH enhancing the transcriptional activity of p53.Since promyelocytic leukemia protein nuclear body(PML NB)serves as subcellular reactors for SUMO conjugation within the cell,and the PML Ⅳ isoform can specifically enhance the SUMO modifica-tion of p53,we have investigated the interaction between FLASH and PML Ⅳ,and elucidated the struc-tural basis of their interaction:both FLASH-N3A(501-802)and FLASH-C2(1 807-1 981)bind to PML Ⅳ(aa 228-633).Further investigations reveal that they can synergistically enhance global SUMO1 modification as well as SUMO1 modification of p53.The interaction between FLASH and tumor suppres-sors p53 or PML Ⅳ enriches our understanding of its function and reveals the potential mechanism of FLASH in tumor development,therefore offering novel insights into cancer diagnosis and treatment.

Objective:To investigate the effect of genetic polymorphism of MTHFR C677T (rs1801133) on methotrexate (MTX) related toxicity in pediatric mature B-cell lymphoma patients. Methods:Fifty-eight intermediate and high risk patients under 18 years of age with mature B-cell lymphoma who received 5 g/m2 MTX (24 h intravenous infusion) in Sun Yat-sen University Cancer Center from August 2014 to December 2021 were included,and their toxicity of high-dose MTX (HD-MTX) were monitored and analyzed. Results:Among the 58 pediatric patients,the number of CC,CT,and TT genotypes for MTHFR C677T was 33,19 and 6,respectively. A total of 101 courses of HD-MTX therapy were counted,of which plasma MTX level>0.2 μmol/L at 48 h post-MTX infusion were observed in 35 courses,≤0.2 μmol/L in 66 courses. Inter-group comparison showed that plasma MTX level>0.2 μmol/L at 48 h post-MTX infusion increased the risk of developing oral mucositis (P<0.05). Compared with wild-type (CC genotype),patients in the mutant group (CT+TT genotype) were more likely to develop myelosuppression,manifested as anemia,leucopenia,neutropenia and thrombocytopenia. However,plasma MTX level at 48 h was not associated with MTHFR C677T gene polymorphism. Conclusion:The risk of developing oral mucositis in children with mature B-cell lymphoma is associated with plasma MTX concentration. Polymorphism of MTHFR C677T gene is not related to plasma MTX concentration in children with mature B-cell lymphoma,but is related to grade Ⅲ to Ⅳ hematological toxicity.

Objective:To explore the clinical manifestations,diagnosis,pathological features and treatment of small-cell carci-noma of the prostate(SCCP).Methods:We conducted a retrospective analysis of the clinical and pathological data of 2 cases of confirmed SCCP treated from November 2017 to March 2018,and reviewed relevant literature.Results:Both the patients had the symptoms of frequent,urgent and difficult urination,with an elevated level of PSA and grades Ⅱ-Ⅲ enlargement of the prostate at palpation.One underwent prostate puncture biopsy and the other received transurethral 1470 laser vaporization resection of the tumor.Postoperative pathology indicated prostate adenocarcinoma accompanied by SCCP in both of the cases.One of them was treated by eto-poside-platinum(EP)chemotherapy and died of systemic multiple organ failure 20 months after diagnosis,while the other underwent endocrine therapy and has lived with tumor up to the present day.Conclusion:The incidence rate of SCCP is low,its malignancy is high,and its prognosis is poor.The average survival of the patient is about 7 to 10 months after diagnosis.Currently there is no effec-tive management of the dissease,except by relying on the experience of the treatment of small-cell lung cancer,with chemotherapy as the main option.

Objective:To evaluate the efficacy and prognostic factors of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with secondary acute myeloid leukemia (sAML) .Methods:In this multicenter, retrospective clinical study, adult patients aged ≥18 years who underwent allo-HSCT for sAML at four centers of the Zhejiang Hematopoietic Stem Cell Transplantation Collaborative Group from January 2014 to November 2022 were included, and the efficacy and prognostic factors of allo-HSCT were analyzed.Results:A total of 95 patients were enrolled; 66 (69.5%) had myelodysplastic syndrome-acute myeloid leukemia (MDS-AML) , 4 (4.2%) had MDS/MPN-AML, and 25 (26.3%) had therapy-related AML (tAML) . The 3-year CIR, LFS, and overall survival (OS) rates were 18.6% (95% CI 10.2%-27.0%) , 70.6% (95% CI 60.8%-80.4%) , and 73.3% (95% CI 63.9%-82.7%) , respectively. The 3-year CIRs of the M-AML group (including MDS-AML and MDS/MPN-AML) and the tAML group were 20.0% and 16.4%, respectively ( P=0.430) . The 3-year LFSs were 68.3% and 75.4%, respectively ( P=0.176) . The 3-year OS rates were 69.7% and 75.4%, respectively ( P=0.233) . The 3-year CIRs of the groups with and without TP53 mutations were 60.0% and 13.7%, respectively ( P=0.003) ; the 3-year LFSs were 20.0% and 76.5%, respectively ( P=0.002) ; and the 3-year OS rates were 40.0% and 77.6%, respectively ( P=0.002) . According to European LeukmiaNet 2022 (ELN2022) risk stratification, the 3-year CIRs of patients in the low-, intermediate-, and high-risk groups were 8.3%, 17.8%, and 22.6%, respectively ( P=0.639) . The three-year LFSs were 91.7%, 69.5%, and 65.6%, respectively ( P=0.268) . The 3-year OS rates were 91.7%, 71.4%, and 70.1%, respectively ( P=0.314) . Multivariate analysis revealed that advanced disease at allo-HSCT and TP53 mutations were independent risk factors for CIR, LFS, and OS. Conclusion:There was no significant difference in the prognosis of patients who underwent allo-HSCT among the MDS-AML, MDS/MPN-AML, and tAML groups. Advanced disease at transplantation and TP53 mutations were poor prognostic factors. ELN2022 risk stratification had limited value for predicting the prognosis of patients with sAML following allo-HSCT.

Objective:To analyze the sensitivity of cytoplasmic light-chain immunofluorescence with fluorescence in situ hybridization in bone marrow smears (new FISH) for detecting cytogenetic abnormalities in multiple myeloma (MM) .Methods:42 MM patients admitted to the First Affiliated Hospital of Nanjing Medical University from April 2022 to October 2023 were enrolled. The patients with MM were detected by new FISH and CD138 immunomagnetic bead sorting technology combined with FISH (MACS-FISH) or cytoplasmic immunoglobulin FISH (cIg-FISH) to analyze cytogenetic detection results using combination probes which included 1q21/1p32, p53, IgH, IgH/FGFR3 [t (4;14) ], and IgH/MAF [t (14;16) ].Results:In 23 patients with MM, the abnormality detection rates of cIg-FISH and new FISH were 95.7% and 100.0%, respectively ( P>0.05). The detection rates of 1q21+, 1p32-, p53 deletion, and IgH abnormalities by cIg-FISH and new FISH were consistent, which were 52.2%, 8.7%, 17.4%, and 65.2%, respectively. The results of the two methods further performed with t (4;14) and t (14;16) in patients with IgH abnormalities were identical. The positive rate of t (4;14) was 26.7%, whereas t (14;16) was not detected. In 19 patients with MM, the abnormality detection rates of MACS-FISH and new FISH were 73.7% and 63.2%, respectively ( P>0.05). The positivity rate of 1q21+, 1p32- and IgH abnormalities detected by MACS-FISH were slightly higher than those detected by new FISH; however, the differences were not statistically significant (all P values >0.05) . Conclusion:The new FISH method has a higher detection rate of cytogenetic abnormalities in patients with MM and has good consistency with MACS-FISH and cIg-FISH.

Drug use monitoring and evaluation play a key role in promoting drugs to return to clinical value,optimizing the basic medicine system,and improving the drug supply guarantee system.In order to promote the implementation of drug use monitoring and evaluation in medical institutions,the Pharmaceutical Affairs Committee of the Chinese Hospital Association led the efforts of organizing relevant domestic experts to follow the group standard development process.It successfully formulated the group standard of Drug Use Monitoring and Evaluation through the steps of problem sorting,framework construction,evidence collection,draft writing,opinion consultation,and standard formation.This article introduces the standard formulation process in detail,and explains and analyzes the content of the standard,aiming to help readers better understand the connotation of drug use monitoring and evaluation,and provide practical guidance.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

Bone organoids can simulate the complex structure and function of the bone tissues, which makes them a frontier technology in organoid researches. Bone organoids show a tremendous potential of applications in bone disease modeling, bone injury repair, and medicine screening. Although advancements have been made so far in constructing bone organoids with functional structures like mineralization, bone marrow, trabecular bone, callus, woven bone, etc, the researches in this field are confronted with numerous challenges such as lack of standardized construction strategies and unified evaluation criteria, which limits their further promotion and application. To standardize researches in bone organoids, the Orthopedic Expert Committee of Geriatric Branch of Chinese Association of Gerontology and Geriatrics, the Youth Osteoporosis Group of Orthopedic Branch of Chinese Medical Association, the Osteoporosis Group of Orthopedic Surgeon Branch of Chinese Medical Doctor Association, and the Osteoporosis Committee of Shanghai Association of Integrated Traditional Chinese and Western Medicine organized related experts to formulate Expert consensus on the construction, evaluation, and application of bone organoids ( version 2024) based on an evidence-based approach. A total of 17 recommendations were put forth, aiming to standardize researches and clinical applications of bone organoids and enhance their value in scientific research and clinical practice.

Objective:To investigate alterations in the glymphatic system of spinocerebellar ataxia type 3 (SCA3) patients based on quantitative MRI, and its association with genetic information and motor dysfunction.Methods:The study was a cross-sectional study. This prospective study recruited 39 confirmed SCA3 patients (SCA3 group) and 40 matched healthy controls (HC group) who were seen at the Southwest Hospital of Army Medical University from May 2017 to June 2023. All subjects underwent cranial MRI scanning. Clinical assessments were conducted on all participants using the scale for the assessment and rating of ataxia (SARA) and the international cooperative ataxia rating scale (ICARS). The automatic segmentation and volume measurement of the choroid plexus based on Freesurfer 6.0; the perivascular interstitial space (PVS) was automatically segmented based on the deep-learning model VB-Net, and the volume of the PVS in each brain region was quantified after manual correction. Independent samples t-test and Mann-Whitney U-test were used to analyze the changes in the class lymphatic system in the SCA3 group and the HC group. Pearson partial correlation analysis was used to explore the relationship between CAG repeats, the glymphatic system, and motor dysfunction. Results:The standardized choroid plexus volume in the SCA3 group was (1.24±0.36)×10 3 mm 3, and that in the HC group was (0.96±0.34)×10 3 mm 3, with a statistically significant difference ( t=4.01, P<0.001). PVS volumes in the frontal lobe, temporal lobe, parietal lobe, basal ganglia, cerebellum, thalamus, and brainstem regions in the SCA3 group were significantly higher than those of HC group ( P<0.05). Partial correlation analysis revealed that CAG repeats in SCA3 group were positively correlated with SARA, ICARS, and basal ganglia PVS volumes ( r=0.65, 0.58, 0.29; P=0.001, 0.001, 0.042). Cerebellar and temporal lobe PVS volumes were positively correlated with SARA ( r=0.59, 0.47; P=0.001, 0.003), and positively correlated with ICARS scores ( r=0.61, 0.40; P=0.001, 0.011). Choroid plexus volume was positively correlated with cerebellar and basal ganglia PVS volumes ( r=0.41, 0.31; P=0.009, 0.043). Conclusions:The glymphatic system of SCA3 patients have significant alteration and have association with CAG repeats and motor dysfunction.