AIM:To study the genetic alteration in ACF and to define the possibility that ACF may be a very early morphological lesion with molecular changes,and to explore the relationship between ACF and colorectal adenoma even...AIM:To study the genetic alteration in ACF and to define the possibility that ACF may be a very early morphological lesion with molecular changes,and to explore the relationship between ACF and colorectal adenoma even carcinoma. METHODS: DNA from 35 CRC, 15 adenomas, 34 ACF and 10 normal mucus was isolated by means of microdissection. Direct gene sequencing of K-ras gene including codon 12, 13 and 61 as well as the mutation cluster region (MCR) of APC gene was performed. RESULTS: K-ras gene mutation frequency in ACF, adenoma and carcinoma was 17.6% (6/34), 13.3% (2/15), and 14.3% (5/35) respectively, showing no difference (P 】 0.05) in K-ras gene mutation among three pathologic procedures. The K-ras gene mutation in adenoma, carcinoma and 4 ACF restricted in codon 12 (GGT GAT), but the other 2 mutations from ACF located in codon 13 (GGC GAC). K-ras gene mutation was found more frequently in older patients and patients with polypoid cancer. No mutation in codon 61 was found in the three tissue types. Mutation rate of APC gene in adenoma and carcinoma was 22.9% (8/35) and 26.7% (4/15), which was higher than ACF (2.9%) (P 【0.05). APC gene mutation in carcinoma was not correlated with age of patients, location, size and differentiation of tumor. CONCLUSION: ACF might be a very early morphological lesion in the tumorogenesis of colorectal tumor. The morphological feature and gene mutation status was different in ACF and adenoma. ACF is possibly putative microadenoma that might be the precursor of adenoma. In addition, the development of a subgroup of colorectal carcinomas might undergo a way of normal epithelium ACF carcinomas .展开更多
AIM:To investigate the functions of promoter hypermethylation of O6-methylguanine-DNA methyltransferase(MGMT)gene in colorectal tumorigenesis and progression.METHODS:The promoter hypermethylation of MGMT gene was dete...AIM:To investigate the functions of promoter hypermethylation of O6-methylguanine-DNA methyltransferase(MGMT)gene in colorectal tumorigenesis and progression.METHODS:The promoter hypermethylation of MGMT gene was detected in 27 sporadic colorectal adenomas,62 sporadic colorectal carcinomas and 20 normal colorectal mucosa tissues by methylation-specific PCR.At the same time,the expression of MGMT protein was carried out in the same samples using immunohistochemistry.Mutantallele-specific amplification was used to detect K-rasG to A point mutation in codon 12.RESULTS:None of the normal colorectal mucosa tissues showed methylated bands.Promoter hypermethylation was detected in 40.7%(11 of 27)of adenomas and 43.5%(27 of 62)of carcinomas.MGMT proteins were expressed in nucleus and cytoplasm of normal colorectal mucosa tissues.Loss of MGMT expression was found in 22.2%(6 of 27)of adenomas and 45.2%(28 of 62)of carcinomas.The difference between them was significant(P=0.041).In the 6 adenomas and 28 carcinomas losing MGMT expression,5 and 24 cases presented methylation,respectively(P=0.027,P<0.001).Thirteen of the 19 colorectal tumors with K-rasG to A point mutation in codon 12 had methylated MGMT(P=0.011).The frequencies of K-rasG to A point mutation were 35.3%(12 of 34)and 12.7%(7 of 55)in tumors losing MGMT expression and with normal expression,respectively.CONCLUSION:Promoter hypermethylation and loss of expression of MGMT gene were common events in colorectal tumorigenesis,and loss of expression of MGMT occurs more frequently in carcinomas than in adenomas in sporadic patients.Hypermethylation of the CpG island of MGMT gene was associated with loss of MGMT expression and K-ras G to A point mutation in colorectal tumor.The frequency of K-ras G to A point mutation was increased in tumors losing MGMT expression.It suggests that epigenetic inactivation of MGMT plays an important role in colorectal neoplasia.展开更多
Objective:To study the role of the mutations of p53, APC and K-ras genes in 47 cases of 3 types of intestinal metaplasia (IM) of gastric mucosa. Methods:In 47 cases of IM, exons 5- 8 of p53 and exons 15 of APC were ex...Objective:To study the role of the mutations of p53, APC and K-ras genes in 47 cases of 3 types of intestinal metaplasia (IM) of gastric mucosa. Methods:In 47 cases of IM, exons 5- 8 of p53 and exons 15 of APC were examined with PCR-SSCP and codon 12 of K-ras with PCR-RFLP to detect the existence of any mutations of these structures. Results:Muta- tions of p53, APC and K-ras were found in 29.8% (14/47),6.4% (3/47) and 6.4% (3/47) respectively in our series of patients who consisted of 33 with types I and II and 14 with type III of IM. The mutation rate of p53 was far higher in patients with type III IM (57.1%,8/14) than in those with types I and II IM(18.2%,6/33)(P <0.05). Though the mutation rate of APC and K-ras was also higher in the patients with type III IM than in those with types I and II IM, it was of no statistical significance (P >0.05). In one case of type III IM, mutation of both p53 and K-ras was found. Conclusion: The molecular changes of 3 types of IM are different. The mutation of p53 may be closely related to carcinogenesis in cases of type III IM and it serve as a sign for the early diagnosis of gastric carcinoma.展开更多
To evaluate the feasibility and clinical significance of the PCR SSP technique in detecting K ras gene mutation at codon 12 in pancreatic adenocarcinoma tissues. 80 specimens of surgical resection or biopsy samples ...To evaluate the feasibility and clinical significance of the PCR SSP technique in detecting K ras gene mutation at codon 12 in pancreatic adenocarcinoma tissues. 80 specimens of surgical resection or biopsy samples were tested at our hospital from January 1994 to September 1995. Three different special sequence primers (SSP) synthesized according to mutation styles of CGT, GTT, GAT were respectively prepared. Three amplification reactions were performed for each sample. The amplification products were analyzed by conventional polyacrylamide gel electrophoresis, stained with ethidium bromide and observed under UV transillumination. Results: All of the 34 pancreatic adenocarcinoma samples had positive PCR results with the mutation rate 100%. 7 cases were CGT mutation, 18 GGT and 17 GAT mutation, in which 2 types of mutation existed in 8 cases. No mutation appeared in 13 normal pancreatic tissues, 6 insulinomas, 6 chronic pancreatitis, 5 benign pancreatic cysts, 7 bile duct carcinoma, 5 ampulla carcinoma and 4 carcinomas of duodenal papilla. Conclusion: Pancreatic adenocarcinoma is one of the commonly encounted tumors and is still very difficult to diagnose at the early stage and to distinguish from other lesions preoperatively. Our study indicates that PCR SSP is an ideal assay in comparison with other methods to detect K ras gene mutation. It is simple, rapid, specific, sensitive and easily generalized for clinical application on preoperative diagnosis.展开更多
Objective： To detect the style of K-ras gene point mutation in human pancreatic cancer cell line PANC-1 and decide the bp sequence of Ras target position interfered by RNA. Methods： Three kinds of special sequence p...Objective： To detect the style of K-ras gene point mutation in human pancreatic cancer cell line PANC-1 and decide the bp sequence of Ras target position interfered by RNA. Methods： Three kinds of special sequence primers （SSP） for polymerase chain reaction （PCR） with regard to the mutation styles （OAT, COT and GOT） at codon 12 of K-ras were used to study the human pancreatic cancer cell line PANC-1. The amplification products were studied with polyacrylamine gel electrophoresis to detect the style of point mutation. Results： The style of K-ras gene point mutation at codon 12 was OAT in human pancreatic cancer cell line. Conclusion： PCR-SSP is rapid, convenient and high specific. The results provide a basis for further gene therapy by RNA interference for pancreatic cancer.展开更多
In a total of 83 UN specimens were investigated for proto-oncogene mutations, tumor supressor genes promoter methylation status and c-myc and Ki-67 expression. Point mutations in c-myc were detected in cases with high...In a total of 83 UN specimens were investigated for proto-oncogene mutations, tumor supressor genes promoter methylation status and c-myc and Ki-67 expression. Point mutations in c-myc were detected in cases with high grade and proliferation index. Mutated K-ras proto-onco- gene profiles were detected in 17 (21%) tumoral spiecemens that examined. Tumor specimens were also showed hypermethylated promoter domain for the SFRP2, MGMT tumor supressor genes. These findings showed the combine effect of mutated c-myc and K-ras oncogene and epigenetic inactivation of tissue specific tumor supressor genes (TS) play a crucial role in tumor progression and recurrence in UN carcinogenesis.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
Objective:Keratoconus(KC)is a progressive corneal ectasia disorder,arising from a myriad of causes including genetic predispositions,environmental factors,biomechanical influences,and inflammatory reactions.This study...Objective:Keratoconus(KC)is a progressive corneal ectasia disorder,arising from a myriad of causes including genetic predispositions,environmental factors,biomechanical influences,and inflammatory reactions.This study aims to identify potential pathogenetic gene mutations in patients with sporadic KC in the Han Chinese population.Methods:Twenty-five patients with primary KC as well as 50 unrelated population matched healthy controls,were included in this study to identify potential pathogenic gene mutations among sporadic KC patients in the Han Chinese population.Sanger sequencing and whole-exome sequencing(WES)were used to analyze mutations in the zinc finger protein 469(ZNF469)gene.Bioinformatics analysis was conducted to explore the potential role of ZNF469 in KC pathogenesis.Results:Five novel heterozygous missense variants were identified in KC patients.Among them,2 compound heterozygous variants,c.8986G>C(p.E2996Q)with c.11765A>C(p.D3922A),and c.4423C>G(p.L1475V)with c.10633G>A(p.G3545R),were determined to be possible pathogenic factors for KC.Conclusion:Mutations in the ZNF469 gene may contribute to the development of KC in the Han Chinese population.These mutation sites may provide valuable information for future genetic screening of KC patients and their families.展开更多
AIM:To identify and assess mutations in the K-ras and BRAF genes in a cohort of Chinese patients with colorectal cancer (CRC) for their association with various clinicopathological parameters and prognosis.METHODS:Gen...AIM:To identify and assess mutations in the K-ras and BRAF genes in a cohort of Chinese patients with colorectal cancer (CRC) for their association with various clinicopathological parameters and prognosis.METHODS:Genomic DNA was isolated from frozen tissues.Pyrosequencing analysis was conducted to detect mutations in the K-ras (codons 12,13,and 61) and BRAF genes (codon 600).Statistical analysis was carried out using SPSS-15.0 software.RESULTS:Among the 118 colorectal cancer patients,we detected 41 (34.7%) mutations in the K-ras gene.Mutation frequencies at codon 12 and codon 13 were 23.7% (28/118) and 10.2% (12/118),respectively.Only one patient harbored a point mutation at codon 61 (0.8%,1/118).Gender was the only factor that showed an obvious relationship with K-ras gene mutation (female 44.7% vs male 28.2%,P=0.037).Other clinicopathological features,such as age,location of the tumor,tumor differentiation,Tumor,Node and Metastases classification,and the Union for International Cancer Control staging,showed no positive relationship with K-ras gene mutations.No significant correlation was observed between the presence of K-ras mutations (codons 12,13,and 61) and the survival of the patients.BRAF mutations were rare,and only two patients (1.7%) harbored a detectable mutation at codon 600.CONCLUSION:K-ras gene mutation is a common event in our 118 Chinese CRC patients,with an obvious relationship with gender.However,it seems not to be an independent prognostic factor in CRC patients.The BRAF gene is rarely mutated in Chinese CRC patients.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
BACKGROUND Dystrophic epidermolysis bullosa is characterized by fragile ulcerations of the skin caused by mutations in specific genes.However,genetic typing of this con-dition is rare.CASE SUMMARY An 11-year-old femal...BACKGROUND Dystrophic epidermolysis bullosa is characterized by fragile ulcerations of the skin caused by mutations in specific genes.However,genetic typing of this con-dition is rare.CASE SUMMARY An 11-year-old female suffered from recurrent fever,visible ulcerations of the entire skin,and severe malnutrition.Genetic testing revealed a frameshift mu-tation in the coding region 4047 of the 35th intron region of COL7A1,and she was diagnosed as malnutrition-type epidermolysis bullosa.Drug therapy(immu-noglobulin,fresh frozen plasma),topical therapy(silver ion dressing),fever redu-ction,cough relief,and promotion of gastrointestinal peristalsis are mainly used for respiratory and gastrointestinal complications.The patient’s condition impro-ved after treatment.CONCLUSION Dystrophic epidermolysis bullosa caused by a new framework shift mutation in COL7A1 should be taken seriously.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
A highly sensitive electrochemiluminescence-polymerase chain reaction (ECL-PCR) method for K-ras point mutation detection is developed. Briefly, K-ras oncogene was amplified by a Ru(bpy)3(2+) (TBR)-labeled forward and...A highly sensitive electrochemiluminescence-polymerase chain reaction (ECL-PCR) method for K-ras point mutation detection is developed. Briefly, K-ras oncogene was amplified by a Ru(bpy)3(2+) (TBR)-labeled forward and a biotin-labeled reverse primer, and followed by digestion with MvaI restriction enzyme, which only cut the wild-type amplicon containing its cutting site. The digested product was then adsorbed to the streptavidin-coated microbead through the biotin label and detected by ECL assay. The experiment results showed that the different genotypes can be clearly discriminated by ECL-PCR method. It is useful in point mutation detection, due to its sensitivity, safety, and simplicity.展开更多
Objective: Molecular targeted drugs have been widely used in clinical application which has successfully prolonged some patients' life. Meanwhile, molecular targeted drug therapy for esophageal cancer are attracti...Objective: Molecular targeted drugs have been widely used in clinical application which has successfully prolonged some patients' life. Meanwhile, molecular targeted drug therapy for esophageal cancer are attracting more and more attention from doctors and experts. However, little study has been done towards the effect of this approach for treating esophageal squamous cell carcinoma. This paper, therefore, intends to explore the possibilities of applying EGFR-TKI inhibitors or anti-EGFR monoclonal antibody in esophageal squamous cell carcinoma by studying the mutations of EGFR, K-ras and B-raf in the esophageal squamous cell carcinoma tissues. Methods: Thirty-five cases of resected specimens of diagnosed esophageal squamous cell carcinoma with complete clinical and pathological data from January to April 2009 were collected. Pyrophosphate was used for observing the mutations of EGFR, K-ras and B-raf in the esophageal squamous cell carcinoma tissues. Results: Examinations were undertaken respectively to the codon segment 746-754 of exon 19 in EGFR genes, codon 12 and 13 in K-ras genes as well as condon 600 in B-raf genes. No mutation was found in EGFR and B-raf genes with mutation rate 0% (0/35), all of codon 12 in K-ras genes were wild-type without any mutation, while 2 specimens of codon 13 had mutations with mutation rate of 5.71% (2/35). Conclusion: In treating esophageal squamous cell carcinoma patients, all K-ras genes are expressed as wild type due to low mutation rate; cetuximab is effective due to low mutation rate of B-raf while EGFR-TKI inhibitor will not be effective enough because of low mutation rate of EGFR genes.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
AIMS To examine the prevalance of p53 mutations in hepatocellular carcinoma (HCC) from Chongqing area and the relationship between the p53 mutations and clinicopathological features of HCC,as well as the risk factors....AIMS To examine the prevalance of p53 mutations in hepatocellular carcinoma (HCC) from Chongqing area and the relationship between the p53 mutations and clinicopathological features of HCC,as well as the risk factors. METHODS The overexpression and point mutations of tumor suppressor gene p53 in 38 cases of HCC were detected by a sensitive antigen retrieval fluid (ARF) immunohistochemical method and polymerase chain re- action(PCR)-restriction fragment length polymorphism (RFLP),and single strand conformation polymorphism (SSCP)-silver staining analysis. RESULTS The results showed that 16 of 38 HCCs had positive p53 protein (42.1%),7 HCCs had p53 mutation at 249 (18.4 % ) and 2 HCCS had point muta- tion within exon 7 other than 249. Among 9 cases of HCC with mutations,8 cases demonstrated positive p53 protein,its coincidental rate was 88.9%. The overexpression and mutations of p53 were significantly related to the differentiation and metastasis of HCCs. The frequency of p53 mutations was consistent with high prevalence of HBV and a moderate aflatoxin B1 (AFB1) exposure in our area. CONCLUSIONS The results suggest that AFB1 acts synergistically with HBV in the generation of p53 mutations. Furthermore,dietary exposure to AFB1 may mainly contribute to the tumor specific mutation at codon 249,while HBV may account for other scattered mutations in HCC.展开更多
AIMS p53 gene is one of the focuses in the study of tu- mour suppressor genes.So far,there is still controversy about the relationship between p53 alterations and clinicolpathological parameters of gastic cancers such...AIMS p53 gene is one of the focuses in the study of tu- mour suppressor genes.So far,there is still controversy about the relationship between p53 alterations and clinicolpathological parameters of gastic cancers such as macroscopic classifica- tion,stage,degree of differentiation,depth of tumour invasion and lymphonod metastasis.Tamura has reported that p53 gene mutations mainly occur in the aneuploid tumours.But in China, nothing is reported in this field of study.Our aim is to analyze the relationship between p53 gene mutations and these param- eters including DNA ploidy in Chinese primary gasrtic cancers. METHODS Mutations of the p53 gene in exon5-8 were examined in 20 cases of primary gasric cancer by PCR-SSCP (Polymerase-chain-reaction-single-strand-conforma- tion-polymorphism)analysis. RESULTS Mutations were detected in 8(40%)cases:2 cases in exon5-6,2 cases in exon7,4 cases in exon8.These mutations were detected from stage 0 to stage Ⅲ No significant association was found between p53 gene mutations and the clinicopathological parameters such as macroscopic classifico- tion,degree of histological differentiation,depth of tumour in- vasion and lymphonod metastasis.In addition,66.7%(6 of 9) of aneuploid tumours had p53 mutations and only 18.2%(2 of 11)of diploid tumours had mutations. CONCLUSIONS These results suggest that p53 gene muta- tions are related to DNA ploidy alterations and that p53 gene is one of the important turnout suppressor genes in human gastric cancer.展开更多
INTRODUCTION Hepatocellular carcinoma(HCC)is the mostcommon cause of death from cancer in China.Themechanisms of hepatocarcinogenesis are not yetknown clearly,p16INK4a gene,the multiple tumorsuppressor gene 1(MTS1),en...INTRODUCTION Hepatocellular carcinoma(HCC)is the mostcommon cause of death from cancer in China.Themechanisms of hepatocarcinogenesis are not yetknown clearly,p16INK4a gene,the multiple tumorsuppressor gene 1(MTS1),encodes P16 protein,which acts as an inhibitor by binding directly toCDK4 and CDK6 and preventing its association展开更多
INTRODUCTIONAdenocarcinomas of the cardia are the lesionsarising from the proximal stomach or within 3 cm ofthe gastroesophageal junction.These cancerstended to be advanced at the time of presentation,usually with poo...INTRODUCTIONAdenocarcinomas of the cardia are the lesionsarising from the proximal stomach or within 3 cm ofthe gastroesophageal junction.These cancerstended to be advanced at the time of presentation,usually with poor prognosis.In recent decade,the incidence of adenocarcinoma of gastric eardiaand esophagus are increasing steadily,while therehas been a decrease in the proportion of the cancersarising from the distal stomach.The展开更多
基金This subject is supported by the Fund for Returned Scientists and Scholars,[1999]363.Chinese Ministry of Education.
文摘AIM:To study the genetic alteration in ACF and to define the possibility that ACF may be a very early morphological lesion with molecular changes,and to explore the relationship between ACF and colorectal adenoma even carcinoma. METHODS: DNA from 35 CRC, 15 adenomas, 34 ACF and 10 normal mucus was isolated by means of microdissection. Direct gene sequencing of K-ras gene including codon 12, 13 and 61 as well as the mutation cluster region (MCR) of APC gene was performed. RESULTS: K-ras gene mutation frequency in ACF, adenoma and carcinoma was 17.6% (6/34), 13.3% (2/15), and 14.3% (5/35) respectively, showing no difference (P 】 0.05) in K-ras gene mutation among three pathologic procedures. The K-ras gene mutation in adenoma, carcinoma and 4 ACF restricted in codon 12 (GGT GAT), but the other 2 mutations from ACF located in codon 13 (GGC GAC). K-ras gene mutation was found more frequently in older patients and patients with polypoid cancer. No mutation in codon 61 was found in the three tissue types. Mutation rate of APC gene in adenoma and carcinoma was 22.9% (8/35) and 26.7% (4/15), which was higher than ACF (2.9%) (P 【0.05). APC gene mutation in carcinoma was not correlated with age of patients, location, size and differentiation of tumor. CONCLUSION: ACF might be a very early morphological lesion in the tumorogenesis of colorectal tumor. The morphological feature and gene mutation status was different in ACF and adenoma. ACF is possibly putative microadenoma that might be the precursor of adenoma. In addition, the development of a subgroup of colorectal carcinomas might undergo a way of normal epithelium ACF carcinomas .
基金Supported by the Key Technologies R&D Program of Hubei Province,No.2002AA301C84.
文摘AIM:To investigate the functions of promoter hypermethylation of O6-methylguanine-DNA methyltransferase(MGMT)gene in colorectal tumorigenesis and progression.METHODS:The promoter hypermethylation of MGMT gene was detected in 27 sporadic colorectal adenomas,62 sporadic colorectal carcinomas and 20 normal colorectal mucosa tissues by methylation-specific PCR.At the same time,the expression of MGMT protein was carried out in the same samples using immunohistochemistry.Mutantallele-specific amplification was used to detect K-rasG to A point mutation in codon 12.RESULTS:None of the normal colorectal mucosa tissues showed methylated bands.Promoter hypermethylation was detected in 40.7%(11 of 27)of adenomas and 43.5%(27 of 62)of carcinomas.MGMT proteins were expressed in nucleus and cytoplasm of normal colorectal mucosa tissues.Loss of MGMT expression was found in 22.2%(6 of 27)of adenomas and 45.2%(28 of 62)of carcinomas.The difference between them was significant(P=0.041).In the 6 adenomas and 28 carcinomas losing MGMT expression,5 and 24 cases presented methylation,respectively(P=0.027,P<0.001).Thirteen of the 19 colorectal tumors with K-rasG to A point mutation in codon 12 had methylated MGMT(P=0.011).The frequencies of K-rasG to A point mutation were 35.3%(12 of 34)and 12.7%(7 of 55)in tumors losing MGMT expression and with normal expression,respectively.CONCLUSION:Promoter hypermethylation and loss of expression of MGMT gene were common events in colorectal tumorigenesis,and loss of expression of MGMT occurs more frequently in carcinomas than in adenomas in sporadic patients.Hypermethylation of the CpG island of MGMT gene was associated with loss of MGMT expression and K-ras G to A point mutation in colorectal tumor.The frequency of K-ras G to A point mutation was increased in tumors losing MGMT expression.It suggests that epigenetic inactivation of MGMT plays an important role in colorectal neoplasia.
基金National Natural Science foundation of China, No.39470332
文摘Objective:To study the role of the mutations of p53, APC and K-ras genes in 47 cases of 3 types of intestinal metaplasia (IM) of gastric mucosa. Methods:In 47 cases of IM, exons 5- 8 of p53 and exons 15 of APC were examined with PCR-SSCP and codon 12 of K-ras with PCR-RFLP to detect the existence of any mutations of these structures. Results:Muta- tions of p53, APC and K-ras were found in 29.8% (14/47),6.4% (3/47) and 6.4% (3/47) respectively in our series of patients who consisted of 33 with types I and II and 14 with type III of IM. The mutation rate of p53 was far higher in patients with type III IM (57.1%,8/14) than in those with types I and II IM(18.2%,6/33)(P <0.05). Though the mutation rate of APC and K-ras was also higher in the patients with type III IM than in those with types I and II IM, it was of no statistical significance (P >0.05). In one case of type III IM, mutation of both p53 and K-ras was found. Conclusion: The molecular changes of 3 types of IM are different. The mutation of p53 may be closely related to carcinogenesis in cases of type III IM and it serve as a sign for the early diagnosis of gastric carcinoma.
文摘To evaluate the feasibility and clinical significance of the PCR SSP technique in detecting K ras gene mutation at codon 12 in pancreatic adenocarcinoma tissues. 80 specimens of surgical resection or biopsy samples were tested at our hospital from January 1994 to September 1995. Three different special sequence primers (SSP) synthesized according to mutation styles of CGT, GTT, GAT were respectively prepared. Three amplification reactions were performed for each sample. The amplification products were analyzed by conventional polyacrylamide gel electrophoresis, stained with ethidium bromide and observed under UV transillumination. Results: All of the 34 pancreatic adenocarcinoma samples had positive PCR results with the mutation rate 100%. 7 cases were CGT mutation, 18 GGT and 17 GAT mutation, in which 2 types of mutation existed in 8 cases. No mutation appeared in 13 normal pancreatic tissues, 6 insulinomas, 6 chronic pancreatitis, 5 benign pancreatic cysts, 7 bile duct carcinoma, 5 ampulla carcinoma and 4 carcinomas of duodenal papilla. Conclusion: Pancreatic adenocarcinoma is one of the commonly encounted tumors and is still very difficult to diagnose at the early stage and to distinguish from other lesions preoperatively. Our study indicates that PCR SSP is an ideal assay in comparison with other methods to detect K ras gene mutation. It is simple, rapid, specific, sensitive and easily generalized for clinical application on preoperative diagnosis.
文摘Objective： To detect the style of K-ras gene point mutation in human pancreatic cancer cell line PANC-1 and decide the bp sequence of Ras target position interfered by RNA. Methods： Three kinds of special sequence primers （SSP） for polymerase chain reaction （PCR） with regard to the mutation styles （OAT, COT and GOT） at codon 12 of K-ras were used to study the human pancreatic cancer cell line PANC-1. The amplification products were studied with polyacrylamine gel electrophoresis to detect the style of point mutation. Results： The style of K-ras gene point mutation at codon 12 was OAT in human pancreatic cancer cell line. Conclusion： PCR-SSP is rapid, convenient and high specific. The results provide a basis for further gene therapy by RNA interference for pancreatic cancer.
文摘In a total of 83 UN specimens were investigated for proto-oncogene mutations, tumor supressor genes promoter methylation status and c-myc and Ki-67 expression. Point mutations in c-myc were detected in cases with high grade and proliferation index. Mutated K-ras proto-onco- gene profiles were detected in 17 (21%) tumoral spiecemens that examined. Tumor specimens were also showed hypermethylated promoter domain for the SFRP2, MGMT tumor supressor genes. These findings showed the combine effect of mutated c-myc and K-ras oncogene and epigenetic inactivation of tissue specific tumor supressor genes (TS) play a crucial role in tumor progression and recurrence in UN carcinogenesis.
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.
基金supported by the National Natural Science Foundation(82271057)the Natural Science Foundation of Hunan Province(2023JJ30818),China。
文摘Objective:Keratoconus(KC)is a progressive corneal ectasia disorder,arising from a myriad of causes including genetic predispositions,environmental factors,biomechanical influences,and inflammatory reactions.This study aims to identify potential pathogenetic gene mutations in patients with sporadic KC in the Han Chinese population.Methods:Twenty-five patients with primary KC as well as 50 unrelated population matched healthy controls,were included in this study to identify potential pathogenic gene mutations among sporadic KC patients in the Han Chinese population.Sanger sequencing and whole-exome sequencing(WES)were used to analyze mutations in the zinc finger protein 469(ZNF469)gene.Bioinformatics analysis was conducted to explore the potential role of ZNF469 in KC pathogenesis.Results:Five novel heterozygous missense variants were identified in KC patients.Among them,2 compound heterozygous variants,c.8986G>C(p.E2996Q)with c.11765A>C(p.D3922A),and c.4423C>G(p.L1475V)with c.10633G>A(p.G3545R),were determined to be possible pathogenic factors for KC.Conclusion:Mutations in the ZNF469 gene may contribute to the development of KC in the Han Chinese population.These mutation sites may provide valuable information for future genetic screening of KC patients and their families.
基金Supported by The Department of Education of Zhejiang Province of China,grant No.Y200804314the Zhejiang Provincial Natural Science Foundation,grant No.R2090353+1 种基金the Department of Science and Technology of Zhejiang Province,grant No.2008C33039the Chinese Ministry of Health,grant No.N20100148
文摘AIM:To identify and assess mutations in the K-ras and BRAF genes in a cohort of Chinese patients with colorectal cancer (CRC) for their association with various clinicopathological parameters and prognosis.METHODS:Genomic DNA was isolated from frozen tissues.Pyrosequencing analysis was conducted to detect mutations in the K-ras (codons 12,13,and 61) and BRAF genes (codon 600).Statistical analysis was carried out using SPSS-15.0 software.RESULTS:Among the 118 colorectal cancer patients,we detected 41 (34.7%) mutations in the K-ras gene.Mutation frequencies at codon 12 and codon 13 were 23.7% (28/118) and 10.2% (12/118),respectively.Only one patient harbored a point mutation at codon 61 (0.8%,1/118).Gender was the only factor that showed an obvious relationship with K-ras gene mutation (female 44.7% vs male 28.2%,P=0.037).Other clinicopathological features,such as age,location of the tumor,tumor differentiation,Tumor,Node and Metastases classification,and the Union for International Cancer Control staging,showed no positive relationship with K-ras gene mutations.No significant correlation was observed between the presence of K-ras mutations (codons 12,13,and 61) and the survival of the patients.BRAF mutations were rare,and only two patients (1.7%) harbored a detectable mutation at codon 600.CONCLUSION:K-ras gene mutation is a common event in our 118 Chinese CRC patients,with an obvious relationship with gender.However,it seems not to be an independent prognostic factor in CRC patients.The BRAF gene is rarely mutated in Chinese CRC patients.
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.
文摘BACKGROUND Dystrophic epidermolysis bullosa is characterized by fragile ulcerations of the skin caused by mutations in specific genes.However,genetic typing of this con-dition is rare.CASE SUMMARY An 11-year-old female suffered from recurrent fever,visible ulcerations of the entire skin,and severe malnutrition.Genetic testing revealed a frameshift mu-tation in the coding region 4047 of the 35th intron region of COL7A1,and she was diagnosed as malnutrition-type epidermolysis bullosa.Drug therapy(immu-noglobulin,fresh frozen plasma),topical therapy(silver ion dressing),fever redu-ction,cough relief,and promotion of gastrointestinal peristalsis are mainly used for respiratory and gastrointestinal complications.The patient’s condition impro-ved after treatment.CONCLUSION Dystrophic epidermolysis bullosa caused by a new framework shift mutation in COL7A1 should be taken seriously.
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.
文摘A highly sensitive electrochemiluminescence-polymerase chain reaction (ECL-PCR) method for K-ras point mutation detection is developed. Briefly, K-ras oncogene was amplified by a Ru(bpy)3(2+) (TBR)-labeled forward and a biotin-labeled reverse primer, and followed by digestion with MvaI restriction enzyme, which only cut the wild-type amplicon containing its cutting site. The digested product was then adsorbed to the streptavidin-coated microbead through the biotin label and detected by ECL assay. The experiment results showed that the different genotypes can be clearly discriminated by ECL-PCR method. It is useful in point mutation detection, due to its sensitivity, safety, and simplicity.
文摘Objective: Molecular targeted drugs have been widely used in clinical application which has successfully prolonged some patients' life. Meanwhile, molecular targeted drug therapy for esophageal cancer are attracting more and more attention from doctors and experts. However, little study has been done towards the effect of this approach for treating esophageal squamous cell carcinoma. This paper, therefore, intends to explore the possibilities of applying EGFR-TKI inhibitors or anti-EGFR monoclonal antibody in esophageal squamous cell carcinoma by studying the mutations of EGFR, K-ras and B-raf in the esophageal squamous cell carcinoma tissues. Methods: Thirty-five cases of resected specimens of diagnosed esophageal squamous cell carcinoma with complete clinical and pathological data from January to April 2009 were collected. Pyrophosphate was used for observing the mutations of EGFR, K-ras and B-raf in the esophageal squamous cell carcinoma tissues. Results: Examinations were undertaken respectively to the codon segment 746-754 of exon 19 in EGFR genes, codon 12 and 13 in K-ras genes as well as condon 600 in B-raf genes. No mutation was found in EGFR and B-raf genes with mutation rate 0% (0/35), all of codon 12 in K-ras genes were wild-type without any mutation, while 2 specimens of codon 13 had mutations with mutation rate of 5.71% (2/35). Conclusion: In treating esophageal squamous cell carcinoma patients, all K-ras genes are expressed as wild type due to low mutation rate; cetuximab is effective due to low mutation rate of B-raf while EGFR-TKI inhibitor will not be effective enough because of low mutation rate of EGFR genes.
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.
文摘AIMS To examine the prevalance of p53 mutations in hepatocellular carcinoma (HCC) from Chongqing area and the relationship between the p53 mutations and clinicopathological features of HCC,as well as the risk factors. METHODS The overexpression and point mutations of tumor suppressor gene p53 in 38 cases of HCC were detected by a sensitive antigen retrieval fluid (ARF) immunohistochemical method and polymerase chain re- action(PCR)-restriction fragment length polymorphism (RFLP),and single strand conformation polymorphism (SSCP)-silver staining analysis. RESULTS The results showed that 16 of 38 HCCs had positive p53 protein (42.1%),7 HCCs had p53 mutation at 249 (18.4 % ) and 2 HCCS had point muta- tion within exon 7 other than 249. Among 9 cases of HCC with mutations,8 cases demonstrated positive p53 protein,its coincidental rate was 88.9%. The overexpression and mutations of p53 were significantly related to the differentiation and metastasis of HCCs. The frequency of p53 mutations was consistent with high prevalence of HBV and a moderate aflatoxin B1 (AFB1) exposure in our area. CONCLUSIONS The results suggest that AFB1 acts synergistically with HBV in the generation of p53 mutations. Furthermore,dietary exposure to AFB1 may mainly contribute to the tumor specific mutation at codon 249,while HBV may account for other scattered mutations in HCC.
文摘AIMS p53 gene is one of the focuses in the study of tu- mour suppressor genes.So far,there is still controversy about the relationship between p53 alterations and clinicolpathological parameters of gastic cancers such as macroscopic classifica- tion,stage,degree of differentiation,depth of tumour invasion and lymphonod metastasis.Tamura has reported that p53 gene mutations mainly occur in the aneuploid tumours.But in China, nothing is reported in this field of study.Our aim is to analyze the relationship between p53 gene mutations and these param- eters including DNA ploidy in Chinese primary gasrtic cancers. METHODS Mutations of the p53 gene in exon5-8 were examined in 20 cases of primary gasric cancer by PCR-SSCP (Polymerase-chain-reaction-single-strand-conforma- tion-polymorphism)analysis. RESULTS Mutations were detected in 8(40%)cases:2 cases in exon5-6,2 cases in exon7,4 cases in exon8.These mutations were detected from stage 0 to stage Ⅲ No significant association was found between p53 gene mutations and the clinicopathological parameters such as macroscopic classifico- tion,degree of histological differentiation,depth of tumour in- vasion and lymphonod metastasis.In addition,66.7%(6 of 9) of aneuploid tumours had p53 mutations and only 18.2%(2 of 11)of diploid tumours had mutations. CONCLUSIONS These results suggest that p53 gene muta- tions are related to DNA ploidy alterations and that p53 gene is one of the important turnout suppressor genes in human gastric cancer.
基金the National Natural Science Foundation of China,No.39670702
文摘INTRODUCTION Hepatocellular carcinoma(HCC)is the mostcommon cause of death from cancer in China.Themechanisms of hepatocarcinogenesis are not yetknown clearly,p16INK4a gene,the multiple tumorsuppressor gene 1(MTS1),encodes P16 protein,which acts as an inhibitor by binding directly toCDK4 and CDK6 and preventing its association
文摘INTRODUCTIONAdenocarcinomas of the cardia are the lesionsarising from the proximal stomach or within 3 cm ofthe gastroesophageal junction.These cancerstended to be advanced at the time of presentation,usually with poor prognosis.In recent decade,the incidence of adenocarcinoma of gastric eardiaand esophagus are increasing steadily,while therehas been a decrease in the proportion of the cancersarising from the distal stomach.The
