With the approval of more and more genetically modified(GM)crops in our country,GM safety management has become more important.Transgenic detection is a major approach for transgenic safety management.Nevertheless,a c...With the approval of more and more genetically modified(GM)crops in our country,GM safety management has become more important.Transgenic detection is a major approach for transgenic safety management.Nevertheless,a convenient and visual technique with low equipment requirements and high sensitivity for the field detection of GM plants is still lacking.On the basis of the existing recombinase polymerase amplification(RPA)technique,we developed a multiplex RPA(multi-RPA)method that can simultaneously detect three transgenic elements,including the cauliflower mosaic virus 35S gene(CaMV35S)promoter,neomycin phosphotransferaseⅡgene(NptⅡ)and hygromycin B phosphotransferase gene(Hyg),thus improving the detection rate.Moreover,we coupled this multi-RPA technique with the CRISPR/Cas12a reporter system,which enabled the detection results to be clearly observed by naked eyes under ultraviolet(UV)light(254 nm;which could be achieved by a portable UV flashlight),therefore establishing a multi-RPA visual detection technique.Compared with the traditional test strip detection method,this multi-RPA-CRISPR/Cas12a technique has the higher specificity,higher sensitivity,wider application range and lower cost.Compared with other polymerase chain reaction(PCR)techniques,it also has the advantages of low equipment requirements and visualization,making it a potentially feasible method for the field detection of GM plants.展开更多
Objectives:Monitoring of Cancer Antigen 125(CA125)during ovarian cancer(OC)maintenance treatment with poly(ADP-ribose)polymerase inhibitors(PARPis)may be insufficient when using Gynecologic Cancer Intergroup(GCIG)bioc...Objectives:Monitoring of Cancer Antigen 125(CA125)during ovarian cancer(OC)maintenance treatment with poly(ADP-ribose)polymerase inhibitors(PARPis)may be insufficient when using Gynecologic Cancer Intergroup(GCIG)biochemical progression criteria.This study aimed to evaluate the usefulness of CA125 monitoring in detecting OC recurrence during PARPis maintenance treatment.Methods:This multicenter retrospective cohort study included patients with primary OC who achieved complete or partial response after first-line platinum-based chemotherapy followed by PARPis maintenance treatment.Progressionwas defined using Response EvaluationCriteria in Solid Tumors(RECIST)and GCIG biochemical criteria.New biochemical progression definitions,based on CA125 nadir determined using receiver operating characteristic(ROC)curve analysis,were proposed.Concordance between radiological and biochemical progression was assessed.Results:Of 142 patients,progression was detected in 54(38.03%)and 29(20.42%)using RECIST and GCIG criteria,respectively.The sensitivity,specificity,positive predictive value(PPV),and negative predictive value(NPV)of the GCIG criteria were 53.70%[95%confidence interval(CI):39.61%–67.38%],100.00%[95%CI:95.91%–100.00%],100.00%[95%CI:88.10%–100.00%]and 77.88%[95%CI:72.54%–82.43%],respectively.A cut-off of 1.59×nadir achieved 88.90%sensitivity and 87.20%specificity[Area Under Curve(AUC):91.10%,95%CI:84.70%–97.40%]with a false positive rate(FPR)of 12.67%.Defining biochemical progression as an increase in CA125 of≥3×nadir achieved sensitivity,specificity,PPV,NPV,and FPR of 79.63%[95%CI:66.47%–89.37%],98.86%[95%CI:93.83%–99.97%],97.73%[95%CI:85.91%–99.67%],88.78%[95%CI:82.35%–93.06%],and 1.14%,respectively.Diagnostic accuracy was higher using the≥3×nadir criterion compared with GCIG definition(91.55%vs.82.39%).Conclusion:GCIG biochemical progression criteria during PARPis maintenance treatment after first-line chemotherapymissed 46.3%of progressing patients.Anewcriterion—CA125≥3×nadir—improves sensitivity and NPV,while maintaining high specificity,offering a simple and practical approach for clinical implementation.展开更多
BACKGROUND Recurrence remains the leading cause of poor prognosis in hepatocellular carcinoma(HCC),particularly among patients infected with hepatitis B virus(HBV).The telomerase reverse transcriptase(TERT)promoter is...BACKGROUND Recurrence remains the leading cause of poor prognosis in hepatocellular carcinoma(HCC),particularly among patients infected with hepatitis B virus(HBV).The telomerase reverse transcriptase(TERT)promoter is the most frequently mutated site in HBV-related HCC;however,its prognostic significance is not fully established.AIM To evaluate the prognostic impact of TERT promoter mutations and efficiency of digital polymerase chain reaction(dPCR).METHODS A total of 66 HBV-related HCC patients who underwent hepatectomy were enrolled in this study.DNA extracted from fresh tumor tissues was analyzed for TERT promoter mutations using Sanger sequencing and dPCR.The dPCR assay was optimized by adding 7-deaza-dGTP,CviQ1,and ethylenediaminetetraacetic acid to improve detection sensitivity.Concordance between methods was assessed,and nomogram survival prediction models were developed to evaluate prognostic value based on mutation status.RESULTS TERT promoter mutations were detected in 26/66(39.39%)cases by Sanger sequencing and 30/66(45.45%)by dPCR.The two methods showed high concordance(93.939%,κ=0.876),with dPCR demonstrating 100%sensitivity and 90%specificity.Patients harboring TERT promoter mutations exhibited reduced overall survival and higher recurrence risk.Nomogram models successfully distinguished mutant from non-mutant cases for both overall survival(C-index:0.7651)and disease-free survival(C-index:0.6899).CONCLUSION TERT promoter mutation predicts poor prognosis in HBV-related HCC and serves as a biomarker for risk stratification.Optimized dPCR outperforms Sanger sequencing,and nomograms with TERT status guide precision therapy.展开更多
Pamiparib is a potent and selective oral poly(adenosine diphosphate(ADP)-ribose)-polymerase(PARP)1/2inhibitor(PARPi).Pamiparib has good bioavailability and shows greater cytotoxic potency and similar DNA-trapping capa...Pamiparib is a potent and selective oral poly(adenosine diphosphate(ADP)-ribose)-polymerase(PARP)1/2inhibitor(PARPi).Pamiparib has good bioavailability and shows greater cytotoxic potency and similar DNA-trapping capacity compared to olaparib.It is not affected by adenosine triphosphate(ATP)-binding cassette transporters.展开更多
BACKGROUND Although the relationship between somatic DNA polymerase epsilon(POLE)exonuclease domain mutations(EDMs)and colorectal cancer(CRC)is well established,the role of POLE non-EDMs in CRC remains unclear.AIM To ...BACKGROUND Although the relationship between somatic DNA polymerase epsilon(POLE)exonuclease domain mutations(EDMs)and colorectal cancer(CRC)is well established,the role of POLE non-EDMs in CRC remains unclear.AIM To identify POLE non-EDMs and EDMs in CRC,and to determine their associations with accompanying mutations and microsatellite instability(MSI).METHODS In this retrospective study,next-generation sequencing was performed using a targeted colon cancer panel(Qiagen,DHS-003Z)on 356 CRC patients.Of these,191 patients were found to carry POLE mutations.For these patients,MSI status was assessed using both real-time PCR(EasyPGX^(■)Ready MSI kit)and immunohistochemistry,and accompanying somatic mutations were investigated.RESULTS POLE mutations were identified in 53.65%of the CRC patients.Among the POLE-mutant patients,87.96%were classified as pMMR(MSI-L),and 12.04%as dMMR(MSI-H).The most frequently observed POLE non-EDM variant was exon 34 c.4337_4338delTG p.V1446fs*3.The POLE EDMs were present in exon 14,with two specific variants p.Y458F(0.52%)and p.Y468N(0.52%).The most common pathogenic variants accompanying the POLE mutations were in MLH3,MSH3,KRAS,PIK3CA,and BRAF genes.POLE mutations were associated with a high mutational burden and MSI in CRC,particularly in the dMMR phenotype.This association suggests that POLE mutations may serve as important biomarkers for understanding the genetic profile of the disease and may be used in the clinical management of CRC.CONCLUSION POLE mutations,especially non-EDMs,are frequent in MSI-L CRC and often co-occur with MLH3,MSH3,KRAS,PIK3CA,and BRAF,highlighting their potential role in tumor biology and as biomarkers for personalized treatment.Functional validation and multicenter studies are needed.展开更多
OBJECTIVE:To explore the therapeutic effect and target of atractylenolide I(AT-I)on post-infectious irritable bowel syndrome(PI-IBS)rats.METHODS:Therefore,the preliminarily mechanism of AT-I in anti-PI-IBS were first ...OBJECTIVE:To explore the therapeutic effect and target of atractylenolide I(AT-I)on post-infectious irritable bowel syndrome(PI-IBS)rats.METHODS:Therefore,the preliminarily mechanism of AT-I in anti-PI-IBS were first predicted by network pharmacology and molecular docking,then the possible signaling pathways were systematically analyzed.Finally,the potential therapeutic targets and possible signaling pathways of AT-I on PI-IBS in Sprague-Dawley(SD)rat model were verified by experiments.RESULTS:AT-I could alleviate PI-IBS symptoms and reduce the expression of tumor necrosis factorα,interleukin-6 and Interferon-gamma in PI-IBS SD rat model and inhibit the c-Jun N-terminal kinase/inducible nitric oxide synthase(JNK/iNOS)pathway.Notably,AT-I treatment could inhibit the overexpression of polymeraseⅠand transcript release factor(PTRF).CONCLUSION:AT-I could alleviate PI-IBS symptoms through downregulation of PTRF and inhibiting the JNK/iNOS pathway.This study not only provides a scientific basis to clarify the anti-PI-IBS effect of AT-I and its mechanism but also suggests a novel promising therapeutic strategy to treat the PI-IBS.展开更多
With rapid developments of emerging technologies like synthetic biology,the demand for DNA polymerases with superior activities including higher thermostability and processivity has increased significantly.Thus,ration...With rapid developments of emerging technologies like synthetic biology,the demand for DNA polymerases with superior activities including higher thermostability and processivity has increased significantly.Thus,rational optimization of the performance of DNA polymerase is of great interest.Nuclear magnetic resonance(NMR)spectroscopy is a powerful technique used for studying protein structure and dynamics.It provides the atomic resolution information of enzymes under their functional solution environment to reveal the active sites(hot spots)of the enzyme,which could be further used for optimizing the performance of enzymes.In our previous work,we identified hot spot residues of Pyrococcus furiosus DNA polymerase(Pfu pol).We aim to employ these binding hot spots to screen for co-factors of Pfu pol,particularly targeting those molecules exhibiting weak intermolecular interactions.To validate this concept,we first demonstrated the feasibility of utilizing hot spot residues as screening probes for auxiliary factors by employing the well-characterized Tween-20 as a model system.Employing these hot spots as probes,two new co-factors,the heat shock protein TkHSP20 from Thermococcus Kodakaraensis and the chemical chaperone L-arginine,are identified to interact with Pfu pol to boost its performance in amplifying long DNA fragments by enhancing the thermal stability and the processivity of the Pfu pol.This NMR-based approach requires no prior assignment information of target enzymes,guiding the rational exploration of novel cofactors for Pfu pol.Moreover,our approach is not dependent on structural data or bioinformatics.Therefore,it has significant potential for application in various enzymes to expedite the progress in enzyme engineering.展开更多
DNA fingerprinting among members of the Chinese drug Pu Gong Ying(Taraxacum mongolicum Hand,-Mazz.)and six adulterants of Tu Gong Ying were demonstrated with random-primed polymerase chain reaction(PCR)including arbit...DNA fingerprinting among members of the Chinese drug Pu Gong Ying(Taraxacum mongolicum Hand,-Mazz.)and six adulterants of Tu Gong Ying were demonstrated with random-primed polymerase chain reaction(PCR)including arbitrarily primed polymerase chain reaction(AP-PCR)and random amplified polymorphic DNA(RAPD).Distinctive,reproducible genomic fingerprints from DNA from 7 species belonged to Compositae were generated with two long(20 and 24 mer)and one short(10 mer)randomly chosen primers.The Pu Gong Ying can be differentiated from six species of Tu Gong Ying according to the banding pattems of their amplified DNA on agarose gels.The results showed that AP-PCR and RAPD methods can be used for identifying Chinese drugs.Moreover,the Similarity Indexes of the genomic DNA fingerprints showed that Pu Gong Ying and its adulterants are unrelated.Therefore,AP-PCR and RAPD methods can be used for identifying Chinese drugs.展开更多
真核生物RNA聚合酶Ⅳ(polymerasesⅣ,PolⅣ)和Ⅴ(PolⅤ)是植物特有的RNA指导DNA甲基化(RNA-directed DNA methylation,RdDM)通路的核心酶,介导重要的表观遗传调控过程。当前分子生物学教材对其介绍明显不足,制约了学生对该领域的深入理...真核生物RNA聚合酶Ⅳ(polymerasesⅣ,PolⅣ)和Ⅴ(PolⅤ)是植物特有的RNA指导DNA甲基化(RNA-directed DNA methylation,RdDM)通路的核心酶,介导重要的表观遗传调控过程。当前分子生物学教材对其介绍明显不足,制约了学生对该领域的深入理解。本文基于RNA PolⅣ与RDR2协同组装、RNA PolⅤ转录停滞等最新结构生物学进展,系统阐述其亚基组成、结构特征与功能分工;进而依据建构主义及循证教学原则,提出以概念脚手架和科学叙事法更新教材内容,并引入可视化分析、角色模拟与案例研讨等教学方法,构建了面向知识-能力-素养协同培养的教学范式,为弥合学科前沿与课堂教学的差距提供系统解决方案,并为农林院校分子生物学课程改革与创新人才培养提供了可借鉴的范式。展开更多
Objective: To develop a sensitive, specific and simple method for detection of extremely low numbers of T. pallidum in clinical specimens, as a significant addition to the serologic tests for syphilis diagnosis. Metho...Objective: To develop a sensitive, specific and simple method for detection of extremely low numbers of T. pallidum in clinical specimens, as a significant addition to the serologic tests for syphilis diagnosis. Methods: Double-tube nested PCR(DN-PCR) and single-tube nested PCR(SN-PCR) assays were performed to amplify specific fragments of the DNA poly-merase I gene(polA) of T. pallidum. Sensitivity and specificity of the two PCR assays were tested. Eighty-six whole blood specimens from persons with suspected syphilis were detected by the two nested PCR methods. The TPPA test was used as a comparison for detecting syphilis in sera from corresponding patients. Results: Only specific amplicons could be obtained during amplification of the T. pallidum polA gene and the detection limit was approximately 1 organism when analyzed on gel by the two PCR methods. Of 86 clinical specimens, 62 were positive by TPPA. Of these, 54 and 51 were positive by the DN-PCR and SN-PCR, respectively, which does not represent a statistically significant difference between the two PCR tests. Of 24 TPPA-negative specimens, 5 were positive by both DN-PCR assay and SN-PCR assay. Conclusion: The SN- polA PCR method is extremely sensitive, specific and easy to perform for detecting low numbers of T. pallidum in clinical blood specimens as a complementary to serology for syphilis diagnosis.展开更多
AIM To explore a rapid and easy sequencing method for hepatitis C virus (HCV) genome, and establish a new sequencing method in China. METHODS Polymerase Chain Reaction (PCR) was combined with DNA sequencing techn...AIM To explore a rapid and easy sequencing method for hepatitis C virus (HCV) genome, and establish a new sequencing method in China. METHODS Polymerase Chain Reaction (PCR) was combined with DNA sequencing technique. PCR products were purified by agarose gel electrophoresis, polyacrylamide gel electrophoresis (PAGE), Polyethylene glycol (PEG) respectively. Then in the presence of a 5′ labeling PCR primer, purified PCR products were directly sequenced. By this method, HCV NS5b cDNA from two HCV infected individuals (HC 42 and HC 49) were sequenced.展开更多
Enterobacter cloacae are clinically important as nosocomial pathogens.In order to investigate the genetic diversity of the clinical E.cloacae,237 isolates obtained from routine diagnostic laboratory were examined with...Enterobacter cloacae are clinically important as nosocomial pathogens.In order to investigate the genetic diversity of the clinical E.cloacae,237 isolates obtained from routine diagnostic laboratory were examined with analysis of heat shock protein 60 gene(hsp60)sequence.Based on the neighbor-joining tree of the hsp60 gene sequence,ten genetic clusters of E.cloacae could be isolated from the clinical samples.Three genetic clusters(Ⅲ,ⅥandⅧ)represent almost 71%of the iso-lates;clusterⅠaccounts for 11%;clusterⅦ,ⅩandⅫwere absent.The remaining six clusters are minority in our study,which totally accounted for 18%of all strains.Based on out membrane protein X(ompX)gene sequence analysis of 237 strains,two sets of primers and probes were designed which were specific for ten clusters and cluster I respectively.The limit of detections of the assay were 3.6×10^(1)copiesμL for ten clusters and 2.1×10^(1)copies/μL for cluster I strains within 40 cy-cles.This method was also successfully applied to detect ten clusters and cluster I strains from swab samples,the limit detec-tion for swab samples with inoculated bacteria were 10^4 CFU/mL.In the study,we analyzed the genetic clusters of E.cloacae isolated from hospital setting,and developed a novel real-time polymerase chain reaction method for rapid detection of ten clus-ters and cluster I.展开更多
Poly(ADP-ribose)polymerase(PARP)is a family of proteins that play a crucial role in diverse cellular processes,including DNA repair,cell death,and changes in chromatin structure.PARP inhibitors(PARPi)have been recogni...Poly(ADP-ribose)polymerase(PARP)is a family of proteins that play a crucial role in diverse cellular processes,including DNA repair,cell death,and changes in chromatin structure.PARP inhibitors(PARPi)have been recognized as notable agents in the realm of anticancer therapeutics owing to their capacity to specifically impact DNA repair pathways,thereby inducing targeted death of cancerous cells,particularly in cancers with homologous recombination deficiency(HRD).These inhibitors have been approved for the treatment of several cancers,such as ovarian,breast,and pancreatic cancers.Despite their promising therapeutic attributes,developing resistance to PARPi presents a formidable obstacle,curtailing their overall efficacy.This article presents a comprehensive description of the potential mechanisms related to PARPi resistance,an in-depth study of potential strategies to overcome resistance,and an assessment of the therapeutic potential of the PARPi in combination with alternative therapies.展开更多
基金the Experimental Technology Research Project of Zhejiang University(SYB202138)National Natural Science Foundation of China(32000195)。
文摘With the approval of more and more genetically modified(GM)crops in our country,GM safety management has become more important.Transgenic detection is a major approach for transgenic safety management.Nevertheless,a convenient and visual technique with low equipment requirements and high sensitivity for the field detection of GM plants is still lacking.On the basis of the existing recombinase polymerase amplification(RPA)technique,we developed a multiplex RPA(multi-RPA)method that can simultaneously detect three transgenic elements,including the cauliflower mosaic virus 35S gene(CaMV35S)promoter,neomycin phosphotransferaseⅡgene(NptⅡ)and hygromycin B phosphotransferase gene(Hyg),thus improving the detection rate.Moreover,we coupled this multi-RPA technique with the CRISPR/Cas12a reporter system,which enabled the detection results to be clearly observed by naked eyes under ultraviolet(UV)light(254 nm;which could be achieved by a portable UV flashlight),therefore establishing a multi-RPA visual detection technique.Compared with the traditional test strip detection method,this multi-RPA-CRISPR/Cas12a technique has the higher specificity,higher sensitivity,wider application range and lower cost.Compared with other polymerase chain reaction(PCR)techniques,it also has the advantages of low equipment requirements and visualization,making it a potentially feasible method for the field detection of GM plants.
文摘Objectives:Monitoring of Cancer Antigen 125(CA125)during ovarian cancer(OC)maintenance treatment with poly(ADP-ribose)polymerase inhibitors(PARPis)may be insufficient when using Gynecologic Cancer Intergroup(GCIG)biochemical progression criteria.This study aimed to evaluate the usefulness of CA125 monitoring in detecting OC recurrence during PARPis maintenance treatment.Methods:This multicenter retrospective cohort study included patients with primary OC who achieved complete or partial response after first-line platinum-based chemotherapy followed by PARPis maintenance treatment.Progressionwas defined using Response EvaluationCriteria in Solid Tumors(RECIST)and GCIG biochemical criteria.New biochemical progression definitions,based on CA125 nadir determined using receiver operating characteristic(ROC)curve analysis,were proposed.Concordance between radiological and biochemical progression was assessed.Results:Of 142 patients,progression was detected in 54(38.03%)and 29(20.42%)using RECIST and GCIG criteria,respectively.The sensitivity,specificity,positive predictive value(PPV),and negative predictive value(NPV)of the GCIG criteria were 53.70%[95%confidence interval(CI):39.61%–67.38%],100.00%[95%CI:95.91%–100.00%],100.00%[95%CI:88.10%–100.00%]and 77.88%[95%CI:72.54%–82.43%],respectively.A cut-off of 1.59×nadir achieved 88.90%sensitivity and 87.20%specificity[Area Under Curve(AUC):91.10%,95%CI:84.70%–97.40%]with a false positive rate(FPR)of 12.67%.Defining biochemical progression as an increase in CA125 of≥3×nadir achieved sensitivity,specificity,PPV,NPV,and FPR of 79.63%[95%CI:66.47%–89.37%],98.86%[95%CI:93.83%–99.97%],97.73%[95%CI:85.91%–99.67%],88.78%[95%CI:82.35%–93.06%],and 1.14%,respectively.Diagnostic accuracy was higher using the≥3×nadir criterion compared with GCIG definition(91.55%vs.82.39%).Conclusion:GCIG biochemical progression criteria during PARPis maintenance treatment after first-line chemotherapymissed 46.3%of progressing patients.Anewcriterion—CA125≥3×nadir—improves sensitivity and NPV,while maintaining high specificity,offering a simple and practical approach for clinical implementation.
基金Supported by National Key Research and Development Program of China,No.2023YFF0613304Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences,No.2023-I2M-2-004,No.2024-I2M-C&T-B-069,and No.2025-I2M-C&T-B-057.
文摘BACKGROUND Recurrence remains the leading cause of poor prognosis in hepatocellular carcinoma(HCC),particularly among patients infected with hepatitis B virus(HBV).The telomerase reverse transcriptase(TERT)promoter is the most frequently mutated site in HBV-related HCC;however,its prognostic significance is not fully established.AIM To evaluate the prognostic impact of TERT promoter mutations and efficiency of digital polymerase chain reaction(dPCR).METHODS A total of 66 HBV-related HCC patients who underwent hepatectomy were enrolled in this study.DNA extracted from fresh tumor tissues was analyzed for TERT promoter mutations using Sanger sequencing and dPCR.The dPCR assay was optimized by adding 7-deaza-dGTP,CviQ1,and ethylenediaminetetraacetic acid to improve detection sensitivity.Concordance between methods was assessed,and nomogram survival prediction models were developed to evaluate prognostic value based on mutation status.RESULTS TERT promoter mutations were detected in 26/66(39.39%)cases by Sanger sequencing and 30/66(45.45%)by dPCR.The two methods showed high concordance(93.939%,κ=0.876),with dPCR demonstrating 100%sensitivity and 90%specificity.Patients harboring TERT promoter mutations exhibited reduced overall survival and higher recurrence risk.Nomogram models successfully distinguished mutant from non-mutant cases for both overall survival(C-index:0.7651)and disease-free survival(C-index:0.6899).CONCLUSION TERT promoter mutation predicts poor prognosis in HBV-related HCC and serves as a biomarker for risk stratification.Optimized dPCR outperforms Sanger sequencing,and nomograms with TERT status guide precision therapy.
基金supported in part by funding from BeiGene,Ltd.,USA(Grant No.:KPR081)with additional support from the Alessandra Bono Foundation,Italy.
文摘Pamiparib is a potent and selective oral poly(adenosine diphosphate(ADP)-ribose)-polymerase(PARP)1/2inhibitor(PARPi).Pamiparib has good bioavailability and shows greater cytotoxic potency and similar DNA-trapping capacity compared to olaparib.It is not affected by adenosine triphosphate(ATP)-binding cassette transporters.
文摘BACKGROUND Although the relationship between somatic DNA polymerase epsilon(POLE)exonuclease domain mutations(EDMs)and colorectal cancer(CRC)is well established,the role of POLE non-EDMs in CRC remains unclear.AIM To identify POLE non-EDMs and EDMs in CRC,and to determine their associations with accompanying mutations and microsatellite instability(MSI).METHODS In this retrospective study,next-generation sequencing was performed using a targeted colon cancer panel(Qiagen,DHS-003Z)on 356 CRC patients.Of these,191 patients were found to carry POLE mutations.For these patients,MSI status was assessed using both real-time PCR(EasyPGX^(■)Ready MSI kit)and immunohistochemistry,and accompanying somatic mutations were investigated.RESULTS POLE mutations were identified in 53.65%of the CRC patients.Among the POLE-mutant patients,87.96%were classified as pMMR(MSI-L),and 12.04%as dMMR(MSI-H).The most frequently observed POLE non-EDM variant was exon 34 c.4337_4338delTG p.V1446fs*3.The POLE EDMs were present in exon 14,with two specific variants p.Y458F(0.52%)and p.Y468N(0.52%).The most common pathogenic variants accompanying the POLE mutations were in MLH3,MSH3,KRAS,PIK3CA,and BRAF genes.POLE mutations were associated with a high mutational burden and MSI in CRC,particularly in the dMMR phenotype.This association suggests that POLE mutations may serve as important biomarkers for understanding the genetic profile of the disease and may be used in the clinical management of CRC.CONCLUSION POLE mutations,especially non-EDMs,are frequent in MSI-L CRC and often co-occur with MLH3,MSH3,KRAS,PIK3CA,and BRAF,highlighting their potential role in tumor biology and as biomarkers for personalized treatment.Functional validation and multicenter studies are needed.
基金The University Collaborative Innovation Project of Anhui:Creation of a Combined Animal Model of Coronary Heart Disease based on the Theory of Xin'an Medicine(No.GXXT-2020-024)Start-up Funding for Doctoral Research at Wannan Medical College(WYRCQD2018009)Horizontal Project of South Anhui Medical College(H202003)。
文摘OBJECTIVE:To explore the therapeutic effect and target of atractylenolide I(AT-I)on post-infectious irritable bowel syndrome(PI-IBS)rats.METHODS:Therefore,the preliminarily mechanism of AT-I in anti-PI-IBS were first predicted by network pharmacology and molecular docking,then the possible signaling pathways were systematically analyzed.Finally,the potential therapeutic targets and possible signaling pathways of AT-I on PI-IBS in Sprague-Dawley(SD)rat model were verified by experiments.RESULTS:AT-I could alleviate PI-IBS symptoms and reduce the expression of tumor necrosis factorα,interleukin-6 and Interferon-gamma in PI-IBS SD rat model and inhibit the c-Jun N-terminal kinase/inducible nitric oxide synthase(JNK/iNOS)pathway.Notably,AT-I treatment could inhibit the overexpression of polymeraseⅠand transcript release factor(PTRF).CONCLUSION:AT-I could alleviate PI-IBS symptoms through downregulation of PTRF and inhibiting the JNK/iNOS pathway.This study not only provides a scientific basis to clarify the anti-PI-IBS effect of AT-I and its mechanism but also suggests a novel promising therapeutic strategy to treat the PI-IBS.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences XDB0540000Natural Science Foundation of China grants 22327901,22174151 and 21991080Hubei Provincial Natural Science Foundation of China 2023AFA041。
文摘With rapid developments of emerging technologies like synthetic biology,the demand for DNA polymerases with superior activities including higher thermostability and processivity has increased significantly.Thus,rational optimization of the performance of DNA polymerase is of great interest.Nuclear magnetic resonance(NMR)spectroscopy is a powerful technique used for studying protein structure and dynamics.It provides the atomic resolution information of enzymes under their functional solution environment to reveal the active sites(hot spots)of the enzyme,which could be further used for optimizing the performance of enzymes.In our previous work,we identified hot spot residues of Pyrococcus furiosus DNA polymerase(Pfu pol).We aim to employ these binding hot spots to screen for co-factors of Pfu pol,particularly targeting those molecules exhibiting weak intermolecular interactions.To validate this concept,we first demonstrated the feasibility of utilizing hot spot residues as screening probes for auxiliary factors by employing the well-characterized Tween-20 as a model system.Employing these hot spots as probes,two new co-factors,the heat shock protein TkHSP20 from Thermococcus Kodakaraensis and the chemical chaperone L-arginine,are identified to interact with Pfu pol to boost its performance in amplifying long DNA fragments by enhancing the thermal stability and the processivity of the Pfu pol.This NMR-based approach requires no prior assignment information of target enzymes,guiding the rational exploration of novel cofactors for Pfu pol.Moreover,our approach is not dependent on structural data or bioinformatics.Therefore,it has significant potential for application in various enzymes to expedite the progress in enzyme engineering.
文摘DNA fingerprinting among members of the Chinese drug Pu Gong Ying(Taraxacum mongolicum Hand,-Mazz.)and six adulterants of Tu Gong Ying were demonstrated with random-primed polymerase chain reaction(PCR)including arbitrarily primed polymerase chain reaction(AP-PCR)and random amplified polymorphic DNA(RAPD).Distinctive,reproducible genomic fingerprints from DNA from 7 species belonged to Compositae were generated with two long(20 and 24 mer)and one short(10 mer)randomly chosen primers.The Pu Gong Ying can be differentiated from six species of Tu Gong Ying according to the banding pattems of their amplified DNA on agarose gels.The results showed that AP-PCR and RAPD methods can be used for identifying Chinese drugs.Moreover,the Similarity Indexes of the genomic DNA fingerprints showed that Pu Gong Ying and its adulterants are unrelated.Therefore,AP-PCR and RAPD methods can be used for identifying Chinese drugs.
文摘真核生物RNA聚合酶Ⅳ(polymerasesⅣ,PolⅣ)和Ⅴ(PolⅤ)是植物特有的RNA指导DNA甲基化(RNA-directed DNA methylation,RdDM)通路的核心酶,介导重要的表观遗传调控过程。当前分子生物学教材对其介绍明显不足,制约了学生对该领域的深入理解。本文基于RNA PolⅣ与RDR2协同组装、RNA PolⅤ转录停滞等最新结构生物学进展,系统阐述其亚基组成、结构特征与功能分工;进而依据建构主义及循证教学原则,提出以概念脚手架和科学叙事法更新教材内容,并引入可视化分析、角色模拟与案例研讨等教学方法,构建了面向知识-能力-素养协同培养的教学范式,为弥合学科前沿与课堂教学的差距提供系统解决方案,并为农林院校分子生物学课程改革与创新人才培养提供了可借鉴的范式。
文摘Objective: To develop a sensitive, specific and simple method for detection of extremely low numbers of T. pallidum in clinical specimens, as a significant addition to the serologic tests for syphilis diagnosis. Methods: Double-tube nested PCR(DN-PCR) and single-tube nested PCR(SN-PCR) assays were performed to amplify specific fragments of the DNA poly-merase I gene(polA) of T. pallidum. Sensitivity and specificity of the two PCR assays were tested. Eighty-six whole blood specimens from persons with suspected syphilis were detected by the two nested PCR methods. The TPPA test was used as a comparison for detecting syphilis in sera from corresponding patients. Results: Only specific amplicons could be obtained during amplification of the T. pallidum polA gene and the detection limit was approximately 1 organism when analyzed on gel by the two PCR methods. Of 86 clinical specimens, 62 were positive by TPPA. Of these, 54 and 51 were positive by the DN-PCR and SN-PCR, respectively, which does not represent a statistically significant difference between the two PCR tests. Of 24 TPPA-negative specimens, 5 were positive by both DN-PCR assay and SN-PCR assay. Conclusion: The SN- polA PCR method is extremely sensitive, specific and easy to perform for detecting low numbers of T. pallidum in clinical blood specimens as a complementary to serology for syphilis diagnosis.
文摘AIM To explore a rapid and easy sequencing method for hepatitis C virus (HCV) genome, and establish a new sequencing method in China. METHODS Polymerase Chain Reaction (PCR) was combined with DNA sequencing technique. PCR products were purified by agarose gel electrophoresis, polyacrylamide gel electrophoresis (PAGE), Polyethylene glycol (PEG) respectively. Then in the presence of a 5′ labeling PCR primer, purified PCR products were directly sequenced. By this method, HCV NS5b cDNA from two HCV infected individuals (HC 42 and HC 49) were sequenced.
基金the financial supports of the grants(Mega Project of Research on the Prevention and Control of HIV/AIDS,Viral Hepatitis Infectious Diseases 2011ZX10004-001,2013ZX10004-101 to Ye Chang-yun)from the Ministry of Science and Technology,China
文摘Enterobacter cloacae are clinically important as nosocomial pathogens.In order to investigate the genetic diversity of the clinical E.cloacae,237 isolates obtained from routine diagnostic laboratory were examined with analysis of heat shock protein 60 gene(hsp60)sequence.Based on the neighbor-joining tree of the hsp60 gene sequence,ten genetic clusters of E.cloacae could be isolated from the clinical samples.Three genetic clusters(Ⅲ,ⅥandⅧ)represent almost 71%of the iso-lates;clusterⅠaccounts for 11%;clusterⅦ,ⅩandⅫwere absent.The remaining six clusters are minority in our study,which totally accounted for 18%of all strains.Based on out membrane protein X(ompX)gene sequence analysis of 237 strains,two sets of primers and probes were designed which were specific for ten clusters and cluster I respectively.The limit of detections of the assay were 3.6×10^(1)copiesμL for ten clusters and 2.1×10^(1)copies/μL for cluster I strains within 40 cy-cles.This method was also successfully applied to detect ten clusters and cluster I strains from swab samples,the limit detec-tion for swab samples with inoculated bacteria were 10^4 CFU/mL.In the study,we analyzed the genetic clusters of E.cloacae isolated from hospital setting,and developed a novel real-time polymerase chain reaction method for rapid detection of ten clus-ters and cluster I.
基金supported by the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(No.25-LZIHPS-03)the Regional Innovation System&Education(RISE)program through the Chungbuk Regional Innovation System&Education Center,funded by the Ministry of Education(MOE)and the Chungcheongbuk-do,Republic of Korea(No.2025-RISE-11-014-03).
文摘Poly(ADP-ribose)polymerase(PARP)is a family of proteins that play a crucial role in diverse cellular processes,including DNA repair,cell death,and changes in chromatin structure.PARP inhibitors(PARPi)have been recognized as notable agents in the realm of anticancer therapeutics owing to their capacity to specifically impact DNA repair pathways,thereby inducing targeted death of cancerous cells,particularly in cancers with homologous recombination deficiency(HRD).These inhibitors have been approved for the treatment of several cancers,such as ovarian,breast,and pancreatic cancers.Despite their promising therapeutic attributes,developing resistance to PARPi presents a formidable obstacle,curtailing their overall efficacy.This article presents a comprehensive description of the potential mechanisms related to PARPi resistance,an in-depth study of potential strategies to overcome resistance,and an assessment of the therapeutic potential of the PARPi in combination with alternative therapies.
