A site-directed mutant DNA fragment Neisseria Gonorrhoeae （NG） stains to construct the was synthesized and transfected into clinical transformants that contained the corresponding mutagenesis of regulation region of...A site-directed mutant DNA fragment Neisseria Gonorrhoeae （NG） stains to construct the was synthesized and transfected into clinical transformants that contained the corresponding mutagenesis of regulation region of mtrR gene. According to the technique of gene splicing by overlap extension （SOEing）, a DNA segment with specific mutagenesis was constructed by two-step polymerase chain reaction （PCR）. The mutation fragments EF could be used for the next experiment in which the mutation NG strains were induced. By comparing the recombinant EF fragments to the corresponding DNA fragments of clinical NG strains, 2 of these were not compatible completely. The results of sequencing revealed that there was a 9 bp deletion between the 45 to 54 inverted repeat sequence localized within the mtrR promoter. It can be confirmed that the fragments EF are the specifically designed mutant fragments.展开更多
BACKGROUND Craniometaphyseal dysplasia(CMD)is a rare genetic disorder.Autosomal dominant CMD(AD-CMD)is caused by mutations in the ANKH gene.Affected individuals typically have distinctive facial features including pro...BACKGROUND Craniometaphyseal dysplasia(CMD)is a rare genetic disorder.Autosomal dominant CMD(AD-CMD)is caused by mutations in the ANKH gene.Affected individuals typically have distinctive facial features including progressive thickening of the craniofacial bones.Treatment for AD-CMD primarily consists of surgical intervention to release compression of the cranial nerves and the brain stem/spinal cord.To alleviate progression of the clinical course and improve the quality of life in children waiting to undergo the necessary surgery,we investigated clinical changes in a diagnosed patient with AD-CMD over three years.CASE SUMMARY A 17-mo-old boy presented with progressive nasal obstruction,snoring and hearing loss symptoms.Physical examination showed enlargement of the head circumference and clinical features such as wide nasal bridge,paranasal bossing,widely spaced eyes with an increased bizygomatic width,and a prominent mandible.The patient underwent otolaryngological examination,endoscopy,hearing test,laboratory examination of phosphorus and bone metabolism,cranial and femoral computed tomography,X-ray and next-generation sequencing.The patient was diagnosed with AD-CMD due to p.Phe377 deletion(c.1129_1131del)on exon 9 of the ANKH gene.After adherence to a prescribed low-calcium diet,the boy’s alkaline phosphatase(ALP)levels continuously decreased to within the normal range.However,after 14 mo of dietary intervention,his parents altered his diet to an intermittent low-calcium diet to include milk and eggs.The patient’s ALP was slightly higher than normal after the dietary change but remained close to the normal range.His serum osteocalcin changed to within normal levels after dietary regulation for 33 mo.His serum combined beta C-terminal telopeptide of type I collagen also continuously decreased after the nutritional intervention,although still slightly higher than normal levels.Despite fluctuating blood test results,the boy’s nasal symptoms were markedly relieved and steadily improved after dietary intervention.No significant changes were found in the craniofacial bones by cranial radiography.Close monitoring of clinical features is still ongoing.Calcitriol treatment is currently under consideration and a surgical procedure is planned as necessary in the future.CONCLUSION We herein report the first Chinese case of AD-CMD with heterozygous mutation of p.Phe377 deletion(c.1129_1131del)on the ANKH gene.Biochemical alterations were significantly improved after dietary intervention indicating that a lowcalcium diet may be applied in pediatric AD-CMD patients with ANKH mutations to help alleviate phenotypic manifestations and improve the quality of life before surgical intervention.Further large scale studies are needed to replicate these findings and to establish the appropriate timing for nutritional and surgical interventions。展开更多
BACKGROUND Patients harboring gene mutations like KRAS,NRAS,and BRAF demonstrate highly variable responses to chemotherapy,posing challenges for treatment optimization.Multiparametric magnetic resonance imaging(MRI),w...BACKGROUND Patients harboring gene mutations like KRAS,NRAS,and BRAF demonstrate highly variable responses to chemotherapy,posing challenges for treatment optimization.Multiparametric magnetic resonance imaging(MRI),with its noninvasive capability to assess tumor characteristics in detail,has shown promise in evaluating treatment response and predicting therapeutic outcomes.This technology holds potential for guiding personalized treatment strategies tailored to individual patient profiles,enhancing the precision and effectiveness of colorectal cancer care.AIM To create a multiparametric MRI-based predictive model for assessing chemotherapy efficacy in colorectal cancer patients with gene mutations.METHODS This retrospective study was conducted in a tertiary hospital,analyzing 157 colorectal cancer patients with gene mutations treated between August 2022 and December 2023.Based on chemotherapy outcomes,the patients were categorized into favorable(n=60)and unfavorable(n=50)response groups.Univariate and multivariate logistic regression analyses were performed to identify independent predictors of chemotherapy efficacy.A predictive nomogram was constructed using significant variables,and its performance was assessed using the area under the receiver operating characteristic curve(AUC)in both training and validation sets.RESULTS Univariate analysis identified that tumor differentiation,T2 signal intensity ratio,tumor-to-anal margin distance,and MRI-detected lymph node metastasis as significantly associated with chemotherapy response(P<0.05).Multivariate Logistics regression confirmed these four parameters as independent predictors.The predictive model demonstrated strong discrimination,with an AUC of 0.938(sensitivity:86%;specificity:92%)in the training set,and 0.942(sensitivity:100%;specificity:83%)in the validation set.CONCLUSION We established and validated a multiparametric MRI-based model for predicting chemotherapy response in colorectal cancer patients with gene mutations.This model holds promise for guiding individualized treatment strategies.展开更多
BACKGROUND Rett syndrome is a monogenic X-linked dominant condition that affects 1/(10000-15000)girls due to de novo mutations in the methyl-CpG binding protein 2(MECP2)gene mapped to chromosome Xq28.The disease-causi...BACKGROUND Rett syndrome is a monogenic X-linked dominant condition that affects 1/(10000-15000)girls due to de novo mutations in the methyl-CpG binding protein 2(MECP2)gene mapped to chromosome Xq28.The disease-causing gene was identified as a mutation in the MECP2 gene,which is found in approximately 80%of patients diagnosed with Rett syndrome.Although chromosomal changes resulting in del(15)(q11q13)are usually associated with Angelman and Prader-Willi syndrome,very few cases,if any,of Rett syndrome with terminal 15q22-qter deletion have been published in English literature.CASE SUMMARY In this study,we report an unusual and rare clinical presentation of Rett syndrome in a 12-year-old Sudanese girl.The patient was brought in by her parents,complaining of gradual onset of abnormal walking,abnormal hand movement,loss of speech,and mental retardation for ten years.There was no reported history of convulsions or loss of consciousness.Clinical examination revealed microcephaly with no other apparent dysmorphic features,intact cranial nerves,and abnormal gait.She showed repetitive and stereotyped behaviors,including hand flapping,stimming,and chest pounding,which were concomitant with autism spectrum disorder.Magnetic resonance imaging and electroencephalography investigations were normal,and cytogenetic analysis showed 46,XX,del(15)(q22qter).Further molecular analysis using whole sequencing of MECP2 revealed an alteration cytosine>thymine at nucleotide 401,leading to phenylalanine replacing a serine at amino acid position 134.CONCLUSION This case,the first reported instance of Rett syndrome in Sudan,is of significant interest.The patient carries both the MECP2 gene mutation and the chromosome 15q22-qter deletion,which may explain the autistic behavior with atypical presentation of Rett syndrome.This report expands the genetic diversity of Rett syndrome,demonstrating how co-occurring 15q22-qter deletions can reshape MECP2-associated phenotypes in Rett syndrome.展开更多
BACKGROUND Colorectal cancer(CRC)remains a major global health burden due to its high incidence and mortality,with treatment efficacy often hindered by tumor hetero-geneity,drug resistance,and a complex tumor microenv...BACKGROUND Colorectal cancer(CRC)remains a major global health burden due to its high incidence and mortality,with treatment efficacy often hindered by tumor hetero-geneity,drug resistance,and a complex tumor microenvironment(TME).Lactate metabolism plays a pivotal role in reshaping the TME,promoting immune eva-sion and epithelial-mesenchymal transition,making it a promising target for novel therapeutic strategies and prognostic modeling in CRC.AIM To offer an in-depth analysis of the role of lactate metabolism in CRC,high-lighting its significance in the TME and therapeutic response.METHODS Utilizing single-cell and transcriptomic data from the Gene Expression Omnibus and The Cancer Genome Atlas,we identified key lactate metabolic activities,particularly in the monocyte/macrophage subpopulation.RESULTS Seven lactate metabolism-associated genes were significantly linked to CRC prognosis and used to construct a predictive model.This model accurately forecasts patient outcomes and reveals notable distinct patterns of immune infiltration and transcriptomic profiles mutation profiles between high-and low-risk groups.High-risk patients demonstrated elevated immune cell infiltration,increased mutation frequencies,and heightened sensitivity to specific drugs(AZD6482,tozasertib,and SB216763),providing a foundation for personalized treatment approaches.Additionally,a nomogram integrating clinical and metabolic data effectively predicted 1-,3-,and 5-year survival rates.CONCLUSION This report underscored the pivotal mechanism of lactate metabolism in CRC prognosis and suggest novel avenues for therapeutic intervention.展开更多
Over the past 2 decades,remarkable advancements in the screening,diagnosis,and treatment of non-small cell lung cancer(NSCLC)have led to improved patient outcomes.For the treatment of NSCLC with actionable gene mutati...Over the past 2 decades,remarkable advancements in the screening,diagnosis,and treatment of non-small cell lung cancer(NSCLC)have led to improved patient outcomes.For the treatment of NSCLC with actionable gene mutations,tyrosine kinase inhibitors developed against EGFR,ALK,RET,BRAF,ROS1,NTRK,MET,and KRAS,exhibit substantial antitumor activity and have been incorporated into standard treatment regimens.Additionally,numerous novel therapies,including immunotherapy and antibody-drug conjugate therapy,have been found to benefit patients with NSCLC.This review summarizes current advancements in targeted therapy for NSCLC,according to a systematic search of the PubMed database and synthesis of cutting-edge findings presented at the 2024 American Society of Clinical Oncology Annual Meeting and 2024 World Conference on Lung Cancer.展开更多
BACKGROUND ATP-binding cassette subfamily B member 4(ABCB4)deficiency is associated with cholestatic liver disease primarily because of missense mutations,and many variants remain unidentified.Here,we validate the pat...BACKGROUND ATP-binding cassette subfamily B member 4(ABCB4)deficiency is associated with cholestatic liver disease primarily because of missense mutations,and many variants remain unidentified.Here,we validate the pathogenicity and mechanism of ABCB4 variants in clinical and in vitro trials,hypothesizing that these variants are responsible for impaired biliary function and contribute to the development of cholestatic liver diseases.AIM To clarify the functional features and pathogenicity of ABCB4 variants.METHODS Clinical data were collected from five patients with cholestatic liver disease that was initially not detected by routine examinations.Later,whole-exome sequencing confirmed ABCB4 variants and the patients were treated from January 2017 to December 2023.Pathogenic mechanisms were analyzed using bioinformatics tools,and a cell model in vitro was established to investigate ABCB4 mRNA expression,multidrug resistance protein 3(MDR3)expression,cellular localization,and phosphatidylcholine secretion.Results were compared using Student's t-tests.RESULTS Five missense variants(c.1757T>A,c.1865G>A,c.2362C>T,c.2777C>T and c.3250C>T),one intron variant(c.537-32G>T),and one synonymous(c.C504T)variant were identified.Three of the five patients had various degrees of cholestasis,two presented with liver cirrhosis,and all had elevated gamma-glutamyl transferase.Three of the four patients who underwent a liver biopsy had bile duct dilation,and one had gallstones.Two of the four patients had normal and reduced MDR3 immunohistochemical levels.Bioinformatic analysis indicated that these variants were likely pathogenic except c.C504T variant.None of the missense variants influenced subcellular MDR3 Localization in vitro.However,the c.1865G>A variant significantly decreased ABCB4 mRNA values,and all missense variants down-regulated phosphatidylcholine secretion.CONCLUSION This study uncovered new ABCB4 variants and emphasized the pathogenic potential of specific variants.The findings from five patients provided insight into the pathogenic mechanisms underlying ABCB4-related diseases.展开更多
5-methylcytosine (m5C) as a rare base exists in eucaryotic genomes, it is a normal constituent of many eucaryotic DNA, whose existence is a character of eucaryotic DNA. In the regular physiological conditions, cytosin...5-methylcytosine (m5C) as a rare base exists in eucaryotic genomes, it is a normal constituent of many eucaryotic DNA, whose existence is a character of eucaryotic DNA. In the regular physiological conditions, cytosine residue of eucaryotic DNA is methylated to be popular. Up to the present, many people consider that the m5C may be mutation hotspots by the m5C deamination leading to gene mutation. Our theoretical investigations indicated that the spontaneous mutation caused by the transition of G - C-A - T, in eukaryotic DNA, may be a result caused by the tautomer changing base pairs and may also be caused by other factor actions, however it could not be caused by the deamination of m5C.展开更多
BACKGROUND Gastric cancer is a leading cause of cancer-related mortality worldwide.Many somatic mutations have been identified based on next-generation sequencing;they likely play a vital role in cancer treatment sele...BACKGROUND Gastric cancer is a leading cause of cancer-related mortality worldwide.Many somatic mutations have been identified based on next-generation sequencing;they likely play a vital role in cancer treatment selection.However,nextgeneration sequencing has not been widely used to diagnose and treat gastric cancer in the clinic.AIM To test the mutant gene frequency as a guide for molecular diagnosis and personalized therapy in gastric cancer by use of next-generation sequencing.METHODS We constructed a panel of 24 mutant genes to detect somatic nucleotide variations and copy number variations based on a next-generation sequencing technique.Our custom panel included high-mutation frequency cancer driver and tumour suppressor genes.Mutated genes were also analyzed using the cBioPortal database.The clinical annotation of important variant mutation sites was evaluated in the ClinVar database.We searched for candidate drugs for targeted therapy and immunotherapy from the OncoKB database.RESULTS In our study,the top 16 frequently mutated genes were TP53(58%),ERBB2(28%),BRCA2(23%),NF1(19%),PIK3CA(14%),ATR(14%),MSH2(12%),FBXW7(12%),BMPR1A(12%),ERBB3(11%),ATM(9%),FGFR2(8%),MET(8%),PTEN(6%),CHD4(6%),and KRAS(5%).TP53 is a commonly mutated gene in gastric cancer and has a similar frequency to that in the cBioPortal database.33 gastric cancer patients(51.6%)with microsatellite stability and eight patients(12.5%)with microsatellite instability-high were investigated.Enrichment analyses demonstrated that high-frequency mutated genes had transmembrane receptor protein kinase activity.We discovered that BRCA2,PIK3CA,and FGFR2 gene mutations represent promising biomarkers in gastric cancer.CONCLUSION We developed a powerful panel of 24 genes with high frequencies of mutation that could detect common somatic mutations.The observed mutations provide potential targets for the clinical treatment of gastric cancer.展开更多
AIM： To study the alterations in p53 gene among Indian gastric cancer patients and to correlate them with the various clinicopathological parameters. METHODS： A total of 103 gastric cancer patients were included in ...AIM： To study the alterations in p53 gene among Indian gastric cancer patients and to correlate them with the various clinicopathological parameters. METHODS： A total of 103 gastric cancer patients were included in this study. The p53 alterations were studied by both immunohistochemical method as well as polymerase chain reaction （PCR）-single strand conformation polymorphism （SSCP） analysis. We only studied four （exon 5, 6, 7, and 8） of the 11 ,p53 exons. The alterations in p53 were also correlated with respect to various clinicopathological parameters. RESULTS： Among 103 cases, p53 over-expression and alteration were detected in 37 （35.92%） and 19 （18.44%） cases, respectively. Most of the ,p53 alterations were found at exon 5 （31.54%）, followed by exon 6 （26.31%）, exon 7 （21.04%） and exon 8 （21.04%）. A significant correlation of p53 overexpression was found with p53 alteration （P = 0.000）. Concordance between ,p53 alteration （as detected by SSCP） and over-expression [as detected by immunohistochemistry （IHC）] was found in 75% cases. We found that IHC-positive/SSCP-negative cases accounted for 21% of cases and IHC-negative/SSCP- positive cases accounted for remaining 4% cases. CONCLUSION： Our results show that p53 gene mutations are significantly correlated with p53 protein over-expression, with 75% concordance in over-expression and alteration in the p53 gene, but 25% disconcordance also cautions against the assumption that p53 over-expression is always associated with a gene mutation. There may be other mechanisms responsible for stabilization and accumulation of p53 protein with no evidence of gene mutation that reflect an accumulation of a non-mutated protein, or a false negative SSCP result.展开更多
BACKGROUND: Budd-Chiari syndrome (BCS) is a type of disease characterized by portal hypertension and/or hy- pertension of the inferior vena cava (IVC) due to the ob- struction of the hepatic veins (HV) and/or intrahep...BACKGROUND: Budd-Chiari syndrome (BCS) is a type of disease characterized by portal hypertension and/or hy- pertension of the inferior vena cava (IVC) due to the ob- struction of the hepatic veins (HV) and/or intrahepatic IVC outlet. Being etiologically complicated and obscure, BCS can be acquired or idiopathic and several gene muta- tions may be contributable. This study was to explore whether prothrombin gene mutation (F G20210A) takes part in the pathogenesis of BCS and to investigate their cor- relativity. METHODS: In 38 proven BCS patients and 70 controls, polymerase chain reaction-restriction fragment length poly- morphism (PCR-RFLP) was used to find F G20210A mutation. To detect whether there are any mutations, four steps were taken: purification of genome DNA from whole blood, amplification of special fragment by polymerase chain reaction, digestion of the fragment via restriction en- donuclease, and analysis of results by polyacrylamide gel electrophoresis. RESULTS: F G20210A mutation was not detected in all patients and controls. CONCLUSIONS: No F G20210A mutation exists in Chi- nese patients with BCS, nor correlativity between the oc- currence of BCS and F G20210A mutation. The etiology of BCS in the Chinese needs further investigation.展开更多
To elucidate the molecular pathology underlying the development of hepatocellular carcinoma (HCC), we used 41 highly polymorphic microsatellite markers to examine 55 HCC and corresponding non-tumor liver tissues on ch...To elucidate the molecular pathology underlying the development of hepatocellular carcinoma (HCC), we used 41 highly polymorphic microsatellite markers to examine 55 HCC and corresponding non-tumor liver tissues on chromosome 9, 16 and 17. Loss-of-heterozygosity (LOH) is observed with high frequency on chromosomal region 17p13 (36/55, 65%), 9p21-p23 (28/55, 51%), 16q21-q23 (27/55, 49%) in tumors. Meanwhile, microsatellite instability is rarely found in these microsatellite loci. Direct sequencing was performed to detect the tentative mutation of tumor suppressor genes in these regions: p53, MTS1/p16, and CDH1/E-cadherin. Within exon 5-9 of p53 gene, 14 out of 55 HCC specimens (24%) have somatic mutations, and nucleotide deletion of this gene is reported in HCC for the first time. Mutation in MTS1/pl6 is found only in one tumor case. We do not find mutations in CDH1/E-cadherin. Furthermore, a statistically significant correlation is present between p53 gene mutation and loss of chromosome region 16q21q23 and 9p21-p23, which indicates that synergism between p53 inactivation and deletion of 16q21-q23 and 9p21-p23 may play a role in the pathogenesis of HCC. Genetic aberration in hepatocellular展开更多
Mutations in the X-linked androgen receptor （AR） gene cause androgen insensitivity syndrome （AIS）, resulting in an impaired embryonic sex differentiation in 46,XY genetic men. Complete androgen insensitivity （CAI...Mutations in the X-linked androgen receptor （AR） gene cause androgen insensitivity syndrome （AIS）, resulting in an impaired embryonic sex differentiation in 46,XY genetic men. Complete androgen insensitivity （CAIS） produces a female external phenotype, whereas cases with partial androgen insensitivity （PALS） have various ambiguities of the genitalia. Mild androgen insensitivity （MAIS） is characterized by undermasculinization and gynecomastia. Here we describe a 2-month-old 46,XY female patient, with all of the characteristics of CAIS. Defects in testosterone （T） and dihydrotestosterone （DHT） synthesis were excluded. Sequencing of the AR gene showed the presence in exon 6 of a T to C transition in the second base of codon 790, nucleotide position 2369, causing a novel missense Leu790Pro mutation in the ligand-binding domain of the AR protein. The identification of a novel AR mutation in a girl with CAIS provides significant information due to the importance of missense mutations in the ligand-binding domain of the AR, which are able to induce functional abnormalities in the androgen binding capability, stabilization of active conformation, or interaction with coactivators.展开更多
AIM: To study the characteristics of mismatch repair gene mutation of Chinese hereditary non-polyposis colorectal cancer (HNPCC) and hMLH1 gene promoter methylation, and to improve the screening strategy and explore t...AIM: To study the characteristics of mismatch repair gene mutation of Chinese hereditary non-polyposis colorectal cancer (HNPCC) and hMLH1 gene promoter methylation, and to improve the screening strategy and explore the pertinent test methods. METHODS: A systematic analysis of 30 probands from HNPCC families in the north of China was performed by immunohistochemistry, microsatellite instability (MSI), gene mutation and methylation detection. RESULTS: High frequency microsatellite instability occurred in 25 probands (83.3%) of HNPCC family. Loss of hMLH1 and hMSH2 protein expression accounted for 88% of all microsatellite instability. Pathogenic muta-tion occurred in 14 samples and 3 novel mutational sites were discovered. Deletion of exons 1-6, 1-7 and 8 of hMSH2 was detected in 3 samples and no large fragment deletion was found in hMLH1. Of the 30 probands, hMLH1 gene promoter methylation occurred in 3 probands. The rate of gene micromutation detection combined with large fragment deletion detection was 46.7%-56.7%. The rate of the two methods in combination with methylation detection was 63.3%. CONCLUSION: Scientific and rational detection strategy can improve the detection rate of HNPCC. Based on traditional molecular genetics and combined with epigenetics, multiple detection methods can accurately diagnose HNPCC.展开更多
p53 gene mutation (exon4, 5, 6, 7, 8 and intron6) in gastric cancer and precancerous lesions and p53 gene (exon4 and ontron6), APC gene deletion in gastric carcinomas were studied by PCR/SSCP and PCR/RFLP- Results sho...p53 gene mutation (exon4, 5, 6, 7, 8 and intron6) in gastric cancer and precancerous lesions and p53 gene (exon4 and ontron6), APC gene deletion in gastric carcinomas were studied by PCR/SSCP and PCR/RFLP- Results showed mutation rate of p53 in metaplasia, dysplasia and gastric carcinoma was 37. 5 % (3/8), 42. 11 % (8/19), 53. 33 (16/30) respectively- There was significant dif-ference among groups of metaplasia, dysplasia, cancer and normal controls. Noexon8 mutation was found in metaplasia and dysplasia, but 4 cases were found to have exon8 mutation in cancer group. It is suggested that exon8 mutation occurs at the late stage of gastric cancer, but exon 5, 6, 7 mutation occur in the course ofprecancerous lesion to cancer. Loss of heterozygosity (LOH) of exon4, intron6,APC was 47,37 % (9/19), 8. 73% (2/23), 16. 67 % (3/18) respectively. LOH of exon4 had something to do with poor differentiation, lymph node metastasis,depth of invasion- LOH of exon4 may be one of prognostic marker of gastric cancer. We are led to conclude that p53 gene mutation is an early event and perhaps work together with ras oncogene in gastric carcinogenesis展开更多
Methylmalonic aciduria（MMA） is a common inherited autosomal recessive disorder resulting from defects in the enzyme methylmalonyl CoA mutase（MCM,mut complementation group） or in the synthesis of the MCM cofactor a...Methylmalonic aciduria（MMA） is a common inherited autosomal recessive disorder resulting from defects in the enzyme methylmalonyl CoA mutase（MCM,mut complementation group） or in the synthesis of the MCM cofactor adenosylcobalamin（cbl complementation groups）.The defects in the mut complementation group accounts for the largest number of patients with isolated MMA.At least 200 mutations in the MUT gene on chromosome 6p12 have been identified in MMA patients until now.This study aimed to investigate the clinical characteristics of MMA and genomic variations in the MUT gene of Chinese patients.Genomic DNA was extracted from 18 patients who were diagnosed as having isolated MMA by gas chromatography/mass spectrometry（GC-MS）,and from some of their parents as well.Amplification and direct sequencing of the MUT coding regions（exon 2-13） and their adjacent intronic consensus splice sites were performed in order to identify the disease causing mutations.In this group,six novel mutations in the MUT gene,c.424AG（p.T142A）,c.786TG（p.S262R）,c.808GC（p.G270R）,c.1323_1324insA,c.1445-1GA and c.1676＋77AC were identified.p.T142A and p.G270R were respectively detected at a heterozygous level in one patient.Two previously reported mutations,c.682CT（p.R228X） and c.323GA（p.R108H） were also found in this study.In addition,six previously described single nucleotide polymorphism（SNP）,c.636AG（p.K212K）,c.1495GA（p.A499T）,c.1595AG（p.H532R）,c.1992GA（p.A664A）,c.2011GA（p.V671I） and c.1677-53AG were identified.In this study,we updated the spectrum of MUT mutations and identified the main MMA-causing mutations in Chinese MMA patients.展开更多
AIM： To transfect mutant C-kit cDNA at codon 579 into human embryonic kidney cell line to observe its role in the pathogenesis of gastrointestinal stromal tumor （GIST）. METHODS： Eukaryotic expression vectors of pc...AIM： To transfect mutant C-kit cDNA at codon 579 into human embryonic kidney cell line to observe its role in the pathogenesis of gastrointestinal stromal tumor （GIST）. METHODS： Eukaryotic expression vectors of pcDNA3- Kit-NW and pcDNA3-Kit-W were constructed. Then pcDNA3-Kit-NW and pcDNA3-Kit-W plasrnids were transfected into human embryonic kidney cell line by Upofectamine. The resistant clone was screened by G418 filtration and identified by sequencing, Western blotting, and immunocytochemical staining. Human embryonic kidney cells were divided into three groups including pcDNA3-Kit-NW, pcDNA3-Kit-W, and vector control groups. Absorbency value with a wavelength of 574 nm was detected by MTT analysis. Mice were injected with three groups of cells. Volume, mass, and histological examinations of the tumors in different groups were measured and compared. RESULTS： The C-kit gene and mutant C-kit gene were successfully cloned into the eukaryotic expression vector pcDNA3, pcDNA3-Kit-NW and pcDNA3-Kit-W were successfully transfected into human embryonic kidney cell line and showed stable expression in this cell line. Cell proliferating activity had significant differences between pcDNA3-Kit-NW and pcDNA3, pcDNA3-Kit- NW and pcDNA3-Kit-W （P〈0.05）, respectively. Tumors were only observed in nude mice implanted with cells transfected with pcDNA3-Kit-NW. CONCLUSION： Mutation of C-kit gene increases the proliferation activity of human cells and plays an important role in the malignant transformation of GIST.展开更多
BACKGROUND Colorectal cancer(CRC)is common in elderly patients.Mismatch repair(MMR)protein deletion is one of the causes of CRC.The RAS(KRAS/NRAS),BRAF,and PIK3CA genes are important gene targets in CRC treatment and ...BACKGROUND Colorectal cancer(CRC)is common in elderly patients.Mismatch repair(MMR)protein deletion is one of the causes of CRC.The RAS(KRAS/NRAS),BRAF,and PIK3CA genes are important gene targets in CRC treatment and are closely related to the prognosis and survival of patients.However,little is known regarding the relationship between the expression of MMR,RAS,BRAF,PIK3CA and the clinicopathological features in CRC patients.AIM To analyze the relationship between the expression of MMR,RAS,BRAF,PIK3CA and the clinicopathological features in CRC.METHODS A total of 327 elderly patients with CRC were enrolled,and immunohistochemistry was used to detect the MMR protein.Real-time quantitative polymerase chain reaction was used to detect the RAS(KRAS/NRAS),BRAF,and PIK3CA genes.The clinicopathological data of the patients were recorded and analyzed by SPSS 19.0 statistical software.RESULTS In 327 elderly patients with CRC,the rate of MMR protein loss was 9.79%(32/327),and the deletion rate of four MMR proteins(MSH2,MSH6,MLH1,PMS2)was 1.83%(6/327),3.06%(10/327),7.65%(25/327),and 7.65%(25/327),respectively.There were no significant differences between MMR protein deletion and sex,pathological type,tumor morphology,differentiation degree or lymph node metastasis(P>0.05),but there was a significant difference between MMR protein deletion and tumor diameter and tumor location(P=0.048/P=0.000).The mutation rates of the KRAS,NRAS,BRAF and PIK3CA genes in elderly CRC patients were 44.95%(147/327),2.45%(8/327),3.36%(11/327)and 2.75%(9/327),respectively;the KRAS gene mutation was closely related to tumor morphology(P=0.002)but not to other clinicopathological features(P>0.05),and there were no significant differences between NRAS gene mutation and clinicopathological features(P>0.05).The BRAF gene mutation showed a significant difference in pathological type,tumor location,differentiation degree and lymph node metastasis(P<0.05),but was not correlated with sex,tumor size and tumor morphology(P>0.05).The PIK3CA gene mutation showed no significant differences in the above clinicopathological characteristics(P>0.05).Significant differences were observed between MMR protein deletion and KRAS,BRAF,and PIK3CA gene mutations in elderly CRC patients(P=0.044,P=0.000,P=0.003,respectively),but there was no significant difference between MMR protein deletion and NRAS mutation(P>0.05).CONCLUSION In elderly CRC patients,the tumor is mainly located in the right colon,and the deletion rate of MMR protein is higher when the tumor diameter is greater than or equal to 5 cm;the deletion rate of MLH1 and PMS2 is more common;the mutation rate of KRAS gene is higher than that of the NRAS,BRAF and PIK3CA genes,the BRAF gene mutation has different degrees of correlation with clinicopathological characteristics;when the MMR protein is deleted,the BRAF and PIK3CA gene mutations are often present,and the KRAS gene mutation rate is low.展开更多
Viral variation may change pathogenicity, escape immunity, lead to persistence infection, and cause drug resistance against antiviral therapy. This study was undertaken to investigate the effects of HBV gene variation...Viral variation may change pathogenicity, escape immunity, lead to persistence infection, and cause drug resistance against antiviral therapy. This study was undertaken to investigate the effects of HBV gene variation on the progression of disease and on the efficacy of antiviral therapy for patients with chronic hepatitis B(CHB). METHODS:Hepatitis B virus (HBV) gene mutational sites were detected using gene chip in selected hepatitis B patients. RESULTS:In the patients HBeAg did not show serologic conversion or HBeAg(-)/anti-HBe(+), but their HBV DNA remained positive 24 weeks after α-interferon therapy, which was associated with mutations of nt1896, nt1814, nt1762 and nt1764. In the patients, that HBV DNA levels decreased or were undetectable, but rebounded later after antiviral therapy by lamivudine was associated with mutations of aa528 and(or) aa552(i.e.YMDD mutation), which resulted in lamivudine-resistance. YMDD mutation was prone to occur 52 weeks after lamivudine therapy in some chronic hepatitis B patients (26.4%). Nt1896 mutation was common in most chronic hepatitis B patients (68.5%). Chronic severe hepatitis, cirrhosis, and primary liver carcinoma were related to the mutations of nt1896, nt1762 and nt1764. CONCLUSIONS:HBV gene mutations could aggravate patient's condition and affect the efficacy of antiviral therapy. The regular detection of HBV gene mutation is helpful for identification of disease prognosis and adjustment of therapeutic strategy.展开更多
To detect mutations of the aquaporin 2 gene（AQP2） and the arginine vasopressin V2 receptor gene（AVPR2） of Chinese congenital nephrogenic diabetes insipidus, and to establish the foundation for further studying the...To detect mutations of the aquaporin 2 gene（AQP2） and the arginine vasopressin V2 receptor gene（AVPR2） of Chinese congenital nephrogenic diabetes insipidus, and to establish the foundation for further studying the emergence mechanism of the disease and clinical diagnosis, all the exons and part of introns of AQP2 and AVPR2 genes were amplified with intronic primers, using genomic DNA extracted from three patients with congenital nephrogenic diabetes insipidus and two mothers as template, PCR product was ligated into a T-vector and then sequenced. The result was compared with the database sequence to identify the mutable sites via a BLAST search, the incidence of every mutation was analyzed, and the putative transcription factor binding sites that maybe disturbed were analyzed by MAPPER. Mutation g.1394A〉G in exon 3 of AVPR2 was detected in all the subjects, g.861C〉T（S167L） in exon 2 of AVPR2 and IVS1＋3G〉A in intron of AQP2 were detected, respectively, in two patients, and c.836A〉C in 3′ untranslated region of AQP2 was detected in two patients and one mother. Four mutations were identified. g.1394A〉G of AVPR2 and c.836A〉C of AQP2 have high incidence in patients with nephrogenic diabetes insipidus. Detection on the two sites may become auxiliary diagnosis index of congenital nephrogenic diabetes insipidus.展开更多
基金This project was supported by a grant from National Natural Sciences Foundation of China (No 30371293)
文摘A site-directed mutant DNA fragment Neisseria Gonorrhoeae （NG） stains to construct the was synthesized and transfected into clinical transformants that contained the corresponding mutagenesis of regulation region of mtrR gene. According to the technique of gene splicing by overlap extension （SOEing）, a DNA segment with specific mutagenesis was constructed by two-step polymerase chain reaction （PCR）. The mutation fragments EF could be used for the next experiment in which the mutation NG strains were induced. By comparing the recombinant EF fragments to the corresponding DNA fragments of clinical NG strains, 2 of these were not compatible completely. The results of sequencing revealed that there was a 9 bp deletion between the 45 to 54 inverted repeat sequence localized within the mtrR promoter. It can be confirmed that the fragments EF are the specifically designed mutant fragments.
文摘BACKGROUND Craniometaphyseal dysplasia(CMD)is a rare genetic disorder.Autosomal dominant CMD(AD-CMD)is caused by mutations in the ANKH gene.Affected individuals typically have distinctive facial features including progressive thickening of the craniofacial bones.Treatment for AD-CMD primarily consists of surgical intervention to release compression of the cranial nerves and the brain stem/spinal cord.To alleviate progression of the clinical course and improve the quality of life in children waiting to undergo the necessary surgery,we investigated clinical changes in a diagnosed patient with AD-CMD over three years.CASE SUMMARY A 17-mo-old boy presented with progressive nasal obstruction,snoring and hearing loss symptoms.Physical examination showed enlargement of the head circumference and clinical features such as wide nasal bridge,paranasal bossing,widely spaced eyes with an increased bizygomatic width,and a prominent mandible.The patient underwent otolaryngological examination,endoscopy,hearing test,laboratory examination of phosphorus and bone metabolism,cranial and femoral computed tomography,X-ray and next-generation sequencing.The patient was diagnosed with AD-CMD due to p.Phe377 deletion(c.1129_1131del)on exon 9 of the ANKH gene.After adherence to a prescribed low-calcium diet,the boy’s alkaline phosphatase(ALP)levels continuously decreased to within the normal range.However,after 14 mo of dietary intervention,his parents altered his diet to an intermittent low-calcium diet to include milk and eggs.The patient’s ALP was slightly higher than normal after the dietary change but remained close to the normal range.His serum osteocalcin changed to within normal levels after dietary regulation for 33 mo.His serum combined beta C-terminal telopeptide of type I collagen also continuously decreased after the nutritional intervention,although still slightly higher than normal levels.Despite fluctuating blood test results,the boy’s nasal symptoms were markedly relieved and steadily improved after dietary intervention.No significant changes were found in the craniofacial bones by cranial radiography.Close monitoring of clinical features is still ongoing.Calcitriol treatment is currently under consideration and a surgical procedure is planned as necessary in the future.CONCLUSION We herein report the first Chinese case of AD-CMD with heterozygous mutation of p.Phe377 deletion(c.1129_1131del)on the ANKH gene.Biochemical alterations were significantly improved after dietary intervention indicating that a lowcalcium diet may be applied in pediatric AD-CMD patients with ANKH mutations to help alleviate phenotypic manifestations and improve the quality of life before surgical intervention.Further large scale studies are needed to replicate these findings and to establish the appropriate timing for nutritional and surgical interventions。
基金Supported by Shenzhen High-level Hospital Construction Fund.
文摘BACKGROUND Patients harboring gene mutations like KRAS,NRAS,and BRAF demonstrate highly variable responses to chemotherapy,posing challenges for treatment optimization.Multiparametric magnetic resonance imaging(MRI),with its noninvasive capability to assess tumor characteristics in detail,has shown promise in evaluating treatment response and predicting therapeutic outcomes.This technology holds potential for guiding personalized treatment strategies tailored to individual patient profiles,enhancing the precision and effectiveness of colorectal cancer care.AIM To create a multiparametric MRI-based predictive model for assessing chemotherapy efficacy in colorectal cancer patients with gene mutations.METHODS This retrospective study was conducted in a tertiary hospital,analyzing 157 colorectal cancer patients with gene mutations treated between August 2022 and December 2023.Based on chemotherapy outcomes,the patients were categorized into favorable(n=60)and unfavorable(n=50)response groups.Univariate and multivariate logistic regression analyses were performed to identify independent predictors of chemotherapy efficacy.A predictive nomogram was constructed using significant variables,and its performance was assessed using the area under the receiver operating characteristic curve(AUC)in both training and validation sets.RESULTS Univariate analysis identified that tumor differentiation,T2 signal intensity ratio,tumor-to-anal margin distance,and MRI-detected lymph node metastasis as significantly associated with chemotherapy response(P<0.05).Multivariate Logistics regression confirmed these four parameters as independent predictors.The predictive model demonstrated strong discrimination,with an AUC of 0.938(sensitivity:86%;specificity:92%)in the training set,and 0.942(sensitivity:100%;specificity:83%)in the validation set.CONCLUSION We established and validated a multiparametric MRI-based model for predicting chemotherapy response in colorectal cancer patients with gene mutations.This model holds promise for guiding individualized treatment strategies.
文摘BACKGROUND Rett syndrome is a monogenic X-linked dominant condition that affects 1/(10000-15000)girls due to de novo mutations in the methyl-CpG binding protein 2(MECP2)gene mapped to chromosome Xq28.The disease-causing gene was identified as a mutation in the MECP2 gene,which is found in approximately 80%of patients diagnosed with Rett syndrome.Although chromosomal changes resulting in del(15)(q11q13)are usually associated with Angelman and Prader-Willi syndrome,very few cases,if any,of Rett syndrome with terminal 15q22-qter deletion have been published in English literature.CASE SUMMARY In this study,we report an unusual and rare clinical presentation of Rett syndrome in a 12-year-old Sudanese girl.The patient was brought in by her parents,complaining of gradual onset of abnormal walking,abnormal hand movement,loss of speech,and mental retardation for ten years.There was no reported history of convulsions or loss of consciousness.Clinical examination revealed microcephaly with no other apparent dysmorphic features,intact cranial nerves,and abnormal gait.She showed repetitive and stereotyped behaviors,including hand flapping,stimming,and chest pounding,which were concomitant with autism spectrum disorder.Magnetic resonance imaging and electroencephalography investigations were normal,and cytogenetic analysis showed 46,XX,del(15)(q22qter).Further molecular analysis using whole sequencing of MECP2 revealed an alteration cytosine>thymine at nucleotide 401,leading to phenylalanine replacing a serine at amino acid position 134.CONCLUSION This case,the first reported instance of Rett syndrome in Sudan,is of significant interest.The patient carries both the MECP2 gene mutation and the chromosome 15q22-qter deletion,which may explain the autistic behavior with atypical presentation of Rett syndrome.This report expands the genetic diversity of Rett syndrome,demonstrating how co-occurring 15q22-qter deletions can reshape MECP2-associated phenotypes in Rett syndrome.
基金Supported by Henan Province Science and Technology Research Project,No.232102310043Henan Provincial Science and Technology Research and Development Plan Joint Fund,No.222103810047Key Scientific Research Project Plan of Colleges and Universities in Henan Province,No.22A320033.
文摘BACKGROUND Colorectal cancer(CRC)remains a major global health burden due to its high incidence and mortality,with treatment efficacy often hindered by tumor hetero-geneity,drug resistance,and a complex tumor microenvironment(TME).Lactate metabolism plays a pivotal role in reshaping the TME,promoting immune eva-sion and epithelial-mesenchymal transition,making it a promising target for novel therapeutic strategies and prognostic modeling in CRC.AIM To offer an in-depth analysis of the role of lactate metabolism in CRC,high-lighting its significance in the TME and therapeutic response.METHODS Utilizing single-cell and transcriptomic data from the Gene Expression Omnibus and The Cancer Genome Atlas,we identified key lactate metabolic activities,particularly in the monocyte/macrophage subpopulation.RESULTS Seven lactate metabolism-associated genes were significantly linked to CRC prognosis and used to construct a predictive model.This model accurately forecasts patient outcomes and reveals notable distinct patterns of immune infiltration and transcriptomic profiles mutation profiles between high-and low-risk groups.High-risk patients demonstrated elevated immune cell infiltration,increased mutation frequencies,and heightened sensitivity to specific drugs(AZD6482,tozasertib,and SB216763),providing a foundation for personalized treatment approaches.Additionally,a nomogram integrating clinical and metabolic data effectively predicted 1-,3-,and 5-year survival rates.CONCLUSION This report underscored the pivotal mechanism of lactate metabolism in CRC prognosis and suggest novel avenues for therapeutic intervention.
基金funded by the National Natural Science Foundation of China(Grant no.82172776)Tianjin Health Research Project(Grant no.TJWJ2023XK005)Tianjin Science and Technology Plan Project(Grant no.24ZXGZSY00010).
文摘Over the past 2 decades,remarkable advancements in the screening,diagnosis,and treatment of non-small cell lung cancer(NSCLC)have led to improved patient outcomes.For the treatment of NSCLC with actionable gene mutations,tyrosine kinase inhibitors developed against EGFR,ALK,RET,BRAF,ROS1,NTRK,MET,and KRAS,exhibit substantial antitumor activity and have been incorporated into standard treatment regimens.Additionally,numerous novel therapies,including immunotherapy and antibody-drug conjugate therapy,have been found to benefit patients with NSCLC.This review summarizes current advancements in targeted therapy for NSCLC,according to a systematic search of the PubMed database and synthesis of cutting-edge findings presented at the 2024 American Society of Clinical Oncology Annual Meeting and 2024 World Conference on Lung Cancer.
基金Supported by the National Natural Science Foundation of China,No.81970454.
文摘BACKGROUND ATP-binding cassette subfamily B member 4(ABCB4)deficiency is associated with cholestatic liver disease primarily because of missense mutations,and many variants remain unidentified.Here,we validate the pathogenicity and mechanism of ABCB4 variants in clinical and in vitro trials,hypothesizing that these variants are responsible for impaired biliary function and contribute to the development of cholestatic liver diseases.AIM To clarify the functional features and pathogenicity of ABCB4 variants.METHODS Clinical data were collected from five patients with cholestatic liver disease that was initially not detected by routine examinations.Later,whole-exome sequencing confirmed ABCB4 variants and the patients were treated from January 2017 to December 2023.Pathogenic mechanisms were analyzed using bioinformatics tools,and a cell model in vitro was established to investigate ABCB4 mRNA expression,multidrug resistance protein 3(MDR3)expression,cellular localization,and phosphatidylcholine secretion.Results were compared using Student's t-tests.RESULTS Five missense variants(c.1757T>A,c.1865G>A,c.2362C>T,c.2777C>T and c.3250C>T),one intron variant(c.537-32G>T),and one synonymous(c.C504T)variant were identified.Three of the five patients had various degrees of cholestasis,two presented with liver cirrhosis,and all had elevated gamma-glutamyl transferase.Three of the four patients who underwent a liver biopsy had bile duct dilation,and one had gallstones.Two of the four patients had normal and reduced MDR3 immunohistochemical levels.Bioinformatic analysis indicated that these variants were likely pathogenic except c.C504T variant.None of the missense variants influenced subcellular MDR3 Localization in vitro.However,the c.1865G>A variant significantly decreased ABCB4 mRNA values,and all missense variants down-regulated phosphatidylcholine secretion.CONCLUSION This study uncovered new ABCB4 variants and emphasized the pathogenic potential of specific variants.The findings from five patients provided insight into the pathogenic mechanisms underlying ABCB4-related diseases.
文摘5-methylcytosine (m5C) as a rare base exists in eucaryotic genomes, it is a normal constituent of many eucaryotic DNA, whose existence is a character of eucaryotic DNA. In the regular physiological conditions, cytosine residue of eucaryotic DNA is methylated to be popular. Up to the present, many people consider that the m5C may be mutation hotspots by the m5C deamination leading to gene mutation. Our theoretical investigations indicated that the spontaneous mutation caused by the transition of G - C-A - T, in eukaryotic DNA, may be a result caused by the tautomer changing base pairs and may also be caused by other factor actions, however it could not be caused by the deamination of m5C.
基金Supported by the Science and Technology Foundation of Guangzhou,No.201803010059the Natural Science Foundation of Bengbu Medical College,No.BYKY2019129ZD.
文摘BACKGROUND Gastric cancer is a leading cause of cancer-related mortality worldwide.Many somatic mutations have been identified based on next-generation sequencing;they likely play a vital role in cancer treatment selection.However,nextgeneration sequencing has not been widely used to diagnose and treat gastric cancer in the clinic.AIM To test the mutant gene frequency as a guide for molecular diagnosis and personalized therapy in gastric cancer by use of next-generation sequencing.METHODS We constructed a panel of 24 mutant genes to detect somatic nucleotide variations and copy number variations based on a next-generation sequencing technique.Our custom panel included high-mutation frequency cancer driver and tumour suppressor genes.Mutated genes were also analyzed using the cBioPortal database.The clinical annotation of important variant mutation sites was evaluated in the ClinVar database.We searched for candidate drugs for targeted therapy and immunotherapy from the OncoKB database.RESULTS In our study,the top 16 frequently mutated genes were TP53(58%),ERBB2(28%),BRCA2(23%),NF1(19%),PIK3CA(14%),ATR(14%),MSH2(12%),FBXW7(12%),BMPR1A(12%),ERBB3(11%),ATM(9%),FGFR2(8%),MET(8%),PTEN(6%),CHD4(6%),and KRAS(5%).TP53 is a commonly mutated gene in gastric cancer and has a similar frequency to that in the cBioPortal database.33 gastric cancer patients(51.6%)with microsatellite stability and eight patients(12.5%)with microsatellite instability-high were investigated.Enrichment analyses demonstrated that high-frequency mutated genes had transmembrane receptor protein kinase activity.We discovered that BRCA2,PIK3CA,and FGFR2 gene mutations represent promising biomarkers in gastric cancer.CONCLUSION We developed a powerful panel of 24 genes with high frequencies of mutation that could detect common somatic mutations.The observed mutations provide potential targets for the clinical treatment of gastric cancer.
文摘AIM： To study the alterations in p53 gene among Indian gastric cancer patients and to correlate them with the various clinicopathological parameters. METHODS： A total of 103 gastric cancer patients were included in this study. The p53 alterations were studied by both immunohistochemical method as well as polymerase chain reaction （PCR）-single strand conformation polymorphism （SSCP） analysis. We only studied four （exon 5, 6, 7, and 8） of the 11 ,p53 exons. The alterations in p53 were also correlated with respect to various clinicopathological parameters. RESULTS： Among 103 cases, p53 over-expression and alteration were detected in 37 （35.92%） and 19 （18.44%） cases, respectively. Most of the ,p53 alterations were found at exon 5 （31.54%）, followed by exon 6 （26.31%）, exon 7 （21.04%） and exon 8 （21.04%）. A significant correlation of p53 overexpression was found with p53 alteration （P = 0.000）. Concordance between ,p53 alteration （as detected by SSCP） and over-expression [as detected by immunohistochemistry （IHC）] was found in 75% cases. We found that IHC-positive/SSCP-negative cases accounted for 21% of cases and IHC-negative/SSCP- positive cases accounted for remaining 4% cases. CONCLUSION： Our results show that p53 gene mutations are significantly correlated with p53 protein over-expression, with 75% concordance in over-expression and alteration in the p53 gene, but 25% disconcordance also cautions against the assumption that p53 over-expression is always associated with a gene mutation. There may be other mechanisms responsible for stabilization and accumulation of p53 protein with no evidence of gene mutation that reflect an accumulation of a non-mutated protein, or a false negative SSCP result.
基金This study was partly supported by a grant from the Science and TechnologyKey Project of Henan Province, China ( No. 0224630176 ).
文摘BACKGROUND: Budd-Chiari syndrome (BCS) is a type of disease characterized by portal hypertension and/or hy- pertension of the inferior vena cava (IVC) due to the ob- struction of the hepatic veins (HV) and/or intrahepatic IVC outlet. Being etiologically complicated and obscure, BCS can be acquired or idiopathic and several gene muta- tions may be contributable. This study was to explore whether prothrombin gene mutation (F G20210A) takes part in the pathogenesis of BCS and to investigate their cor- relativity. METHODS: In 38 proven BCS patients and 70 controls, polymerase chain reaction-restriction fragment length poly- morphism (PCR-RFLP) was used to find F G20210A mutation. To detect whether there are any mutations, four steps were taken: purification of genome DNA from whole blood, amplification of special fragment by polymerase chain reaction, digestion of the fragment via restriction en- donuclease, and analysis of results by polyacrylamide gel electrophoresis. RESULTS: F G20210A mutation was not detected in all patients and controls. CONCLUSIONS: No F G20210A mutation exists in Chi- nese patients with BCS, nor correlativity between the oc- currence of BCS and F G20210A mutation. The etiology of BCS in the Chinese needs further investigation.
基金supported by the Chinese High-Tech Program(863)Chinese Key Basic Research Project(973)the National Natural Science Foundation of China.Gratitude was extended to Prof.Zhu CHEN for his suggestion and direction of this work.
文摘To elucidate the molecular pathology underlying the development of hepatocellular carcinoma (HCC), we used 41 highly polymorphic microsatellite markers to examine 55 HCC and corresponding non-tumor liver tissues on chromosome 9, 16 and 17. Loss-of-heterozygosity (LOH) is observed with high frequency on chromosomal region 17p13 (36/55, 65%), 9p21-p23 (28/55, 51%), 16q21-q23 (27/55, 49%) in tumors. Meanwhile, microsatellite instability is rarely found in these microsatellite loci. Direct sequencing was performed to detect the tentative mutation of tumor suppressor genes in these regions: p53, MTS1/p16, and CDH1/E-cadherin. Within exon 5-9 of p53 gene, 14 out of 55 HCC specimens (24%) have somatic mutations, and nucleotide deletion of this gene is reported in HCC for the first time. Mutation in MTS1/pl6 is found only in one tumor case. We do not find mutations in CDH1/E-cadherin. Furthermore, a statistically significant correlation is present between p53 gene mutation and loss of chromosome region 16q21q23 and 9p21-p23, which indicates that synergism between p53 inactivation and deletion of 16q21-q23 and 9p21-p23 may play a role in the pathogenesis of HCC. Genetic aberration in hepatocellular
文摘Mutations in the X-linked androgen receptor （AR） gene cause androgen insensitivity syndrome （AIS）, resulting in an impaired embryonic sex differentiation in 46,XY genetic men. Complete androgen insensitivity （CAIS） produces a female external phenotype, whereas cases with partial androgen insensitivity （PALS） have various ambiguities of the genitalia. Mild androgen insensitivity （MAIS） is characterized by undermasculinization and gynecomastia. Here we describe a 2-month-old 46,XY female patient, with all of the characteristics of CAIS. Defects in testosterone （T） and dihydrotestosterone （DHT） synthesis were excluded. Sequencing of the AR gene showed the presence in exon 6 of a T to C transition in the second base of codon 790, nucleotide position 2369, causing a novel missense Leu790Pro mutation in the ligand-binding domain of the AR protein. The identification of a novel AR mutation in a girl with CAIS provides significant information due to the importance of missense mutations in the ligand-binding domain of the AR, which are able to induce functional abnormalities in the androgen binding capability, stabilization of active conformation, or interaction with coactivators.
基金Supported by Beijing Natural Science Foundation, No. 7062064
文摘AIM: To study the characteristics of mismatch repair gene mutation of Chinese hereditary non-polyposis colorectal cancer (HNPCC) and hMLH1 gene promoter methylation, and to improve the screening strategy and explore the pertinent test methods. METHODS: A systematic analysis of 30 probands from HNPCC families in the north of China was performed by immunohistochemistry, microsatellite instability (MSI), gene mutation and methylation detection. RESULTS: High frequency microsatellite instability occurred in 25 probands (83.3%) of HNPCC family. Loss of hMLH1 and hMSH2 protein expression accounted for 88% of all microsatellite instability. Pathogenic muta-tion occurred in 14 samples and 3 novel mutational sites were discovered. Deletion of exons 1-6, 1-7 and 8 of hMSH2 was detected in 3 samples and no large fragment deletion was found in hMLH1. Of the 30 probands, hMLH1 gene promoter methylation occurred in 3 probands. The rate of gene micromutation detection combined with large fragment deletion detection was 46.7%-56.7%. The rate of the two methods in combination with methylation detection was 63.3%. CONCLUSION: Scientific and rational detection strategy can improve the detection rate of HNPCC. Based on traditional molecular genetics and combined with epigenetics, multiple detection methods can accurately diagnose HNPCC.
文摘p53 gene mutation (exon4, 5, 6, 7, 8 and intron6) in gastric cancer and precancerous lesions and p53 gene (exon4 and ontron6), APC gene deletion in gastric carcinomas were studied by PCR/SSCP and PCR/RFLP- Results showed mutation rate of p53 in metaplasia, dysplasia and gastric carcinoma was 37. 5 % (3/8), 42. 11 % (8/19), 53. 33 (16/30) respectively- There was significant dif-ference among groups of metaplasia, dysplasia, cancer and normal controls. Noexon8 mutation was found in metaplasia and dysplasia, but 4 cases were found to have exon8 mutation in cancer group. It is suggested that exon8 mutation occurs at the late stage of gastric cancer, but exon 5, 6, 7 mutation occur in the course ofprecancerous lesion to cancer. Loss of heterozygosity (LOH) of exon4, intron6,APC was 47,37 % (9/19), 8. 73% (2/23), 16. 67 % (3/18) respectively. LOH of exon4 had something to do with poor differentiation, lymph node metastasis,depth of invasion- LOH of exon4 may be one of prognostic marker of gastric cancer. We are led to conclude that p53 gene mutation is an early event and perhaps work together with ras oncogene in gastric carcinogenesis
基金supported by grants from the National Basic Research Program of China(2005CB522507)the 11th Five-year Plan of National Science & Technology(2006BAI05A07)
文摘Methylmalonic aciduria（MMA） is a common inherited autosomal recessive disorder resulting from defects in the enzyme methylmalonyl CoA mutase（MCM,mut complementation group） or in the synthesis of the MCM cofactor adenosylcobalamin（cbl complementation groups）.The defects in the mut complementation group accounts for the largest number of patients with isolated MMA.At least 200 mutations in the MUT gene on chromosome 6p12 have been identified in MMA patients until now.This study aimed to investigate the clinical characteristics of MMA and genomic variations in the MUT gene of Chinese patients.Genomic DNA was extracted from 18 patients who were diagnosed as having isolated MMA by gas chromatography/mass spectrometry（GC-MS）,and from some of their parents as well.Amplification and direct sequencing of the MUT coding regions（exon 2-13） and their adjacent intronic consensus splice sites were performed in order to identify the disease causing mutations.In this group,six novel mutations in the MUT gene,c.424AG（p.T142A）,c.786TG（p.S262R）,c.808GC（p.G270R）,c.1323_1324insA,c.1445-1GA and c.1676＋77AC were identified.p.T142A and p.G270R were respectively detected at a heterozygous level in one patient.Two previously reported mutations,c.682CT（p.R228X） and c.323GA（p.R108H） were also found in this study.In addition,six previously described single nucleotide polymorphism（SNP）,c.636AG（p.K212K）,c.1495GA（p.A499T）,c.1595AG（p.H532R）,c.1992GA（p.A664A）,c.2011GA（p.V671I） and c.1677-53AG were identified.In this study,we updated the spectrum of MUT mutations and identified the main MMA-causing mutations in Chinese MMA patients.
基金Supported by the National Natural Science Foundation of China No. 30070743 and No. 30471702
文摘AIM： To transfect mutant C-kit cDNA at codon 579 into human embryonic kidney cell line to observe its role in the pathogenesis of gastrointestinal stromal tumor （GIST）. METHODS： Eukaryotic expression vectors of pcDNA3- Kit-NW and pcDNA3-Kit-W were constructed. Then pcDNA3-Kit-NW and pcDNA3-Kit-W plasrnids were transfected into human embryonic kidney cell line by Upofectamine. The resistant clone was screened by G418 filtration and identified by sequencing, Western blotting, and immunocytochemical staining. Human embryonic kidney cells were divided into three groups including pcDNA3-Kit-NW, pcDNA3-Kit-W, and vector control groups. Absorbency value with a wavelength of 574 nm was detected by MTT analysis. Mice were injected with three groups of cells. Volume, mass, and histological examinations of the tumors in different groups were measured and compared. RESULTS： The C-kit gene and mutant C-kit gene were successfully cloned into the eukaryotic expression vector pcDNA3, pcDNA3-Kit-NW and pcDNA3-Kit-W were successfully transfected into human embryonic kidney cell line and showed stable expression in this cell line. Cell proliferating activity had significant differences between pcDNA3-Kit-NW and pcDNA3, pcDNA3-Kit- NW and pcDNA3-Kit-W （P〈0.05）, respectively. Tumors were only observed in nude mice implanted with cells transfected with pcDNA3-Kit-NW. CONCLUSION： Mutation of C-kit gene increases the proliferation activity of human cells and plays an important role in the malignant transformation of GIST.
文摘BACKGROUND Colorectal cancer(CRC)is common in elderly patients.Mismatch repair(MMR)protein deletion is one of the causes of CRC.The RAS(KRAS/NRAS),BRAF,and PIK3CA genes are important gene targets in CRC treatment and are closely related to the prognosis and survival of patients.However,little is known regarding the relationship between the expression of MMR,RAS,BRAF,PIK3CA and the clinicopathological features in CRC patients.AIM To analyze the relationship between the expression of MMR,RAS,BRAF,PIK3CA and the clinicopathological features in CRC.METHODS A total of 327 elderly patients with CRC were enrolled,and immunohistochemistry was used to detect the MMR protein.Real-time quantitative polymerase chain reaction was used to detect the RAS(KRAS/NRAS),BRAF,and PIK3CA genes.The clinicopathological data of the patients were recorded and analyzed by SPSS 19.0 statistical software.RESULTS In 327 elderly patients with CRC,the rate of MMR protein loss was 9.79%(32/327),and the deletion rate of four MMR proteins(MSH2,MSH6,MLH1,PMS2)was 1.83%(6/327),3.06%(10/327),7.65%(25/327),and 7.65%(25/327),respectively.There were no significant differences between MMR protein deletion and sex,pathological type,tumor morphology,differentiation degree or lymph node metastasis(P>0.05),but there was a significant difference between MMR protein deletion and tumor diameter and tumor location(P=0.048/P=0.000).The mutation rates of the KRAS,NRAS,BRAF and PIK3CA genes in elderly CRC patients were 44.95%(147/327),2.45%(8/327),3.36%(11/327)and 2.75%(9/327),respectively;the KRAS gene mutation was closely related to tumor morphology(P=0.002)but not to other clinicopathological features(P>0.05),and there were no significant differences between NRAS gene mutation and clinicopathological features(P>0.05).The BRAF gene mutation showed a significant difference in pathological type,tumor location,differentiation degree and lymph node metastasis(P<0.05),but was not correlated with sex,tumor size and tumor morphology(P>0.05).The PIK3CA gene mutation showed no significant differences in the above clinicopathological characteristics(P>0.05).Significant differences were observed between MMR protein deletion and KRAS,BRAF,and PIK3CA gene mutations in elderly CRC patients(P=0.044,P=0.000,P=0.003,respectively),but there was no significant difference between MMR protein deletion and NRAS mutation(P>0.05).CONCLUSION In elderly CRC patients,the tumor is mainly located in the right colon,and the deletion rate of MMR protein is higher when the tumor diameter is greater than or equal to 5 cm;the deletion rate of MLH1 and PMS2 is more common;the mutation rate of KRAS gene is higher than that of the NRAS,BRAF and PIK3CA genes,the BRAF gene mutation has different degrees of correlation with clinicopathological characteristics;when the MMR protein is deleted,the BRAF and PIK3CA gene mutations are often present,and the KRAS gene mutation rate is low.
文摘Viral variation may change pathogenicity, escape immunity, lead to persistence infection, and cause drug resistance against antiviral therapy. This study was undertaken to investigate the effects of HBV gene variation on the progression of disease and on the efficacy of antiviral therapy for patients with chronic hepatitis B(CHB). METHODS:Hepatitis B virus (HBV) gene mutational sites were detected using gene chip in selected hepatitis B patients. RESULTS:In the patients HBeAg did not show serologic conversion or HBeAg(-)/anti-HBe(+), but their HBV DNA remained positive 24 weeks after α-interferon therapy, which was associated with mutations of nt1896, nt1814, nt1762 and nt1764. In the patients, that HBV DNA levels decreased or were undetectable, but rebounded later after antiviral therapy by lamivudine was associated with mutations of aa528 and(or) aa552(i.e.YMDD mutation), which resulted in lamivudine-resistance. YMDD mutation was prone to occur 52 weeks after lamivudine therapy in some chronic hepatitis B patients (26.4%). Nt1896 mutation was common in most chronic hepatitis B patients (68.5%). Chronic severe hepatitis, cirrhosis, and primary liver carcinoma were related to the mutations of nt1896, nt1762 and nt1764. CONCLUSIONS:HBV gene mutations could aggravate patient's condition and affect the efficacy of antiviral therapy. The regular detection of HBV gene mutation is helpful for identification of disease prognosis and adjustment of therapeutic strategy.
基金the National High Technology Research and Development Program of China(No.2004AA2Z3782)Key Grant of Jilin Science & Technology Committee(No.20060904)+2 种基金Program for New Century Excellent Talents in Universities of China (No.NCET-06-0320)Foundation of Fostering Science and Technology Innovation Program of Northest Normal University (No.NENU-STB07008)Analysis and Testing Foundation of Northest Normal University.
文摘To detect mutations of the aquaporin 2 gene（AQP2） and the arginine vasopressin V2 receptor gene（AVPR2） of Chinese congenital nephrogenic diabetes insipidus, and to establish the foundation for further studying the emergence mechanism of the disease and clinical diagnosis, all the exons and part of introns of AQP2 and AVPR2 genes were amplified with intronic primers, using genomic DNA extracted from three patients with congenital nephrogenic diabetes insipidus and two mothers as template, PCR product was ligated into a T-vector and then sequenced. The result was compared with the database sequence to identify the mutable sites via a BLAST search, the incidence of every mutation was analyzed, and the putative transcription factor binding sites that maybe disturbed were analyzed by MAPPER. Mutation g.1394A〉G in exon 3 of AVPR2 was detected in all the subjects, g.861C〉T（S167L） in exon 2 of AVPR2 and IVS1＋3G〉A in intron of AQP2 were detected, respectively, in two patients, and c.836A〉C in 3′ untranslated region of AQP2 was detected in two patients and one mother. Four mutations were identified. g.1394A〉G of AVPR2 and c.836A〉C of AQP2 have high incidence in patients with nephrogenic diabetes insipidus. Detection on the two sites may become auxiliary diagnosis index of congenital nephrogenic diabetes insipidus.
