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1.
THEBLOCKINGEFFECTSOFGLYCYRRHIZEURALENSISANDCHELIDONIUMMAJUSONMUTAGENESISINDUCEDBYAFLATOXINB1ShiGuizni;史桂芝;JiXinhua;纪新华;LiangY...  相似文献   

2.
CLINICOPATHOLOGICFEATURESANDDIAGNOSISOFCOMBINEDHEPATOCELLULARANDCHOLANGIOCARCINOMALuJianping路建平;CaiWeimin蔡为民;HayashiKeiki1林肇辉...  相似文献   

3.
QUALITATIVESTUDYOFSIALOMUCINSCHANGESDURINGN-METHYL-N-NITROSOUREA-INDUCEDCOLONICCARCINOGENESISINMICEWangQiang王强;WangYuanhe王元和;...  相似文献   

4.
CLONINGANDSEQUENCINGOFIMMUNOGLOBULINVARIABLE-REGIONGENEOFAMONOCLONALANTIBODYSPECIFICFORHUMANHEPATOCARCINOMAYangPing杨萍;GaoLei高...  相似文献   

5.
RESEARCHONSERUMLEVELSOFRETINOL,α-TOCOPHEROLβ-CAROTENE,AND12ELEMENTSINGASTRICDYSPLASIAANDGASTRICCANCERPATIENTSChengWufeng;程五凤;...  相似文献   

6.
AMOLECULAREPIDEMIOLOGICMARKEROFHEPATOCELLULARCARCINOMAFROMAFLATOXINB1CONTAMINATEDAREAINTHESOUTHWESTOFGUANGXIDengZhuolin邓卓霖MaY...  相似文献   

7.
BasicInvestigationsEXPRESSIONOFGAPJUNCTIONPROTEINCx43INCULTUREDHUMANNORMALANDMALIGNANTLUNGCELLSZhangZhiqian;张志谦;LinZhongxiang...  相似文献   

8.
THECOMPARISONSTUDYOFESTABLISHINGANIMALMODELOFHUMANUTERINECANCERUSINGMATRIGELDengXiaohong;邓小虹;SakamotoHideki;SatohKazuo(Depart...  相似文献   

9.
THEEXPRESSIONOFCYTOKERATINSINHUMANHEPATOCELLULARANDCHOLANGIOCELLULARCARCINOMAS¥SuQin;苏勤;Liuyanfang;刘彦仿(DepartmentofPathology,...  相似文献   

10.
STUDYONANTITUMORDRUGINDUCEDAPOPTOSISINHUMANCANCERCELLSBYTERMINALDEOXYNUCLEOTIDYLTRANSFERASEASSAYTongTong童彤SunHanxiao孙含笑Liu...  相似文献   

11.
郁宝铭  余龙 《肿瘤》1997,17(4):190-192
为了解肿瘤抑制基因APC基因在大肠癌中突变的规律。方法应用聚合酶链反应┐单链构象多态性技术(PCR┐SSCP)对30例人大肠癌组织APC基因15号外显子的三个区15┐6、15┐7、15┐8进行了检测。检测步骤主要包括人基因组DNA提取、PCR反应扩增及PCR产物的SSCP分析。结果检查结果显示在第15┐6及15┐7片段上共10例发生了突变,突变率为33.3%。突变的10例中有8例发生于15┐7外显子片段,占突变总数80%(8/10),2例发生于15┐6片段,占突变总数的20%(2/10)。结论证明我国大肠癌患者中存在着APC基因的突变,且15┐7片段是突变集中区。  相似文献   

12.
大肠肿瘤APC基因突变的研究   总被引:4,自引:0,他引:4  
Yu C  Wang J 《中华肿瘤杂志》1998,20(5):348-350
目的检测APC基因在国人散发性大肠肿瘤中的突变情况,并探讨APC基因突变与大肠肿瘤生物学行为的关系。方法采用PCRSSCP、DNA测序对27例(33份标本)大肠息肉,36例大肠癌和相应正常粘膜及3例家族性腺瘤性息肉瘤(FAP)标本中APC基因“突变密集区”(mutationclusterregionMCR)的突变进行了研究。结果大肠息肉和癌组织中,APC基因MCR突变率分别为30.3%(10/33)和35.9%(14/39),两者差异无显著性,而正常大肠粘膜、炎性息肉和增生性息肉均无突变。3例FAP发现有2例突变,其中1例从正常粘膜到腺瘤、到癌变组织均有突变,另1例则在>1.0cm的腺瘤和肝转移癌组织有突变,测序结果证实该例在1425号密码子存在相同点突变。APC突变与肿瘤的临床病理特征无明显的相关性。结论APC不仅在FAP中存在突变,而且在散发性大肠肿瘤中亦存在突变;它的突变至少参与了部分大肠癌的发生发展过程,而且是这一过程中较早发生的事件。  相似文献   

13.
Using single-strand conformation polymorphism we have found two polymorphic sites, AAC to AAT at codon 511 (exon 12) and GCT to GCG at codon 708 (exon 15), in the MCC gene. These sites and an RsaI polymorphic site in APC allowed us to study 23 human small cell lung cancer (SCLC) and 7 non-small cell lung cancer samples for allele loss. Of the 23 SCLC samples, 21 (91%) were informative for one or more of these markers, and we found allele loss in more than 80% (17 of 21). In non-small cell lung cancer samples, 5 of 7 (71%) were informative, and reduction or loss of one allele was found in 2 of 5 (40%). Seven cases were informative for both genes, loss of heterozygosity occurred for both genes in five, one retained heterozygosity for both, and one SCLC had loss of heterozygosity for APC but not for MCC. We conclude that loss of heterozygosity occurs frequently for MCC and APC in lung cancer of all histological types and is very frequent in SCLC. This suggests the presence of tumor suppressor gene(s) in the MCC/APC region of 5q21 involved in human lung cancer.  相似文献   

14.
We report here the use of multiplex fluorescent polymerase chain reaction (PCR) for quantitative allele loss detection using microsatellites with 2-5 base pair repeat motifs. Allele loss of APC, DCC, p53 and RB1 in colorectal tumours has been reported previously using a variety of methods. However, not all workers used intragenic markers. We have used microsatellite polymorphisms which map within, or are closely linked to, these tumour-suppressor gene loci in order to determine whether these loci are indeed the targets for alteration in colorectal cancer. In addition, we have assayed two other tumour-suppressor genes, WT1 and NF1, to see whether they play a role in colorectal carcinogenesis. The putative metastasis-suppressor gene, NM23, was also investigated since there have been conflicting reports about its involvement in colorectal carcinogenesis. Allele loss was detected at the DCC (29%), p53 (66%), RB1 (50%) and NF1 (14%) loci and in the APC/MCC region (50%), but not at the WT1 or NM23 loci. These rapid, and mostly gene-specific, fluorescent multiplex PCR assays for allele loss detection could be modified to devise a single molecular diagnostic test for the important lesions in colorectal cancer.  相似文献   

15.
The molecular mechanisms and candidate genes involved in development of meningiomas still need investigation and elucidation. In the present study 33 meningiomas were analyzed regarding genetic changes of tumor suppressor gene Adenomatous polyposis coli (APC), a component of the wnt signaling. Gene instability was tested by polymerase chain reaction/loss of heterozygosity (LOH) using Restriction Fragment Length Polymorphism (RFLP) method. RFLP was performed by two genetic markers, Rsa I in APC’s exon 11 and Msp I in its exon 15. The results of our analysis showed altogether 15 samples with LOH of the APC gene out of 32 heterozygous patients (47%). Seven patients had LOHs at both exons, while four LOHs were exclusive for exon 11 and four for exon 15. The changes were distributed according to pathohistological grade as follows: 46% of meningothelial meningioma showed LOH; 33% of fibrous; 75% of mixed (transitional); 75% of angiomatous, and one LOH was found in a single case of psammomatous meningioma. None of the LOHs were found in atypical and anaplastic cases. Immunostaining showed that samples with LOHs were accompanied with the absence of APC protein expression or presence of mutant APC proteins (χ2 = 13.81, df = 2, P < 0.001). We also showed that nuclear localization of β-catenin correlates to APC genetic changes (χ2 = 21.96, df = 2, P < 0.0001). The results of this investigation suggest that genetic changes of APC gene play a role in meningioma formation.  相似文献   

16.
Familial adenomatous polyposis (FAP) is an autosomal dominant syndrome predisposing to colorectal cancer and affects 1 in 5-10,000 births. Inheritance of a mutant allele of the adenomatous polyposis coli (APC) gene is the cause of approximately 80% of FAP and 20-30% of an attenuated form of FAP (AFAP), whereas mutations in MUTYH account for a small proportion of the remaining cases. However, the genetic cause of FAP/AFAP in a significant number of families is not known, and cancer risk for individual members of these families cannot be assessed. There is, therefore, an acute need to identify the underlying genetic cause responsible for FAP/AFAP in APC/MUTYH mutation negative families. Hypermethylation of CpG islands in the promoter of tumor suppressor genes can result in gene silencing, has been shown to be functionally equivalent to genetic mutations and can be inherited. Moreover, APC promoter hypermethylation is observed in approximately 20% of sporadic colorectal tumors and correlates with the loss of gene expression. In our study, we used bisulfite treatment and direct sequencing of 2 regulatory regions of APC containing a total of 25 CpG dinucleotides, to investigate the possible role of germline hypermethylation of the APC promoter in FAP and AFAP families that were negative for APC and MUTYH mutations. Analysis of 21 FAP and 39 AFAP families did not identify signs of abnormal promoter methylation, indicating that this form of epigenetic silencing is not a common cause of FAP/AFAP. These results substantially contribute to clarify the potential role of germline epimutations as a cause of inherited predisposition to cancer.  相似文献   

17.
18.
PCR—SSCP法检测大肠癌APC基因MCR区段基因突变   总被引:2,自引:0,他引:2  
以PCR-SSCP方法,分析30例大肠癌原发灶和15例正常粘膜组织的APC基因MCR区段的突变,发现60%(18/30)的大肠癌原发灶中存在APC基因MCR区段的突变。其突变率与肿瘤发生部位、临床病理分期、组织分化程度及淋巴结转移情况无关。结果表明:APC基因突变是大肠癌发生的早期改变,可见于不典型增生的粘膜。检测APC基因突变能预测腺瘤的癌变倾向,有助于早期发现大肠癌。  相似文献   

19.
The genetic basis for the majority of early onset or non-syndromic "familial" colorectal cancer (CRC) is unknown. Attenuated APC phenotype is characterized by relatively few colonic polyps, early age at onset of colon cancer compared with the general population, and inactivating germline mutations within specific regions of the APC gene. We hypothesized that germline mutations within these APC gene regions, might contribute to early onset or familial CRC susceptibility. To test this notion, we analysed 85 Israeli patients with either early onset (< 50 years at diagnosis) or familial CRC for harbouring mutations within the relevant APC gene regions: exons 1-5, exon 9 and a region within exon 15 (spanning nucleotides c.3900 to c.4034; codons 1294 to 1338) using denaturing gradient gel electrophoresis (DGGE), and all of exon 15 employing protein truncation test (PTT). No inactivating, disease-associated mutations were detected in any patient. A novel polymorphism in intron 5 was detected in 16 individuals, 8 patients were carriers of the 11307K variant, a mutation prevalent among Jewish individuals with colorectal cancer, and 4 displayed the E1317Q variant. We conclude that in Israeli individuals with early onset or familial CRC, truncating mutations in the APC gene regions associated with attenuated APC phenotype probably contribute little to disease pathogenesis.  相似文献   

20.
We have investigated loss of heterozygosity (LOH) of the adenomatous polyposis coli (APC) tumor suppressor gene using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) in 86 untreated oral cancer patients, using matched oral cancer tissue and corresponding peripheral blood cell (PBC) DNA samples. PBC from 70 normal healthy individuals, were also analyzed for allelic distribution of APC gene. A 133 bp fragment, spanning exon 11 of the APC gene was amplified, and RsaI digestion of the PCR product defined the alleles as either homozygous 133 bp (Rsa(-/-)) or 87 and 46 bp (Rsa(+/+)) fragments, and heterozygous (Rsa(+/-)) exhibiting the three fragments. Distribution of the three alleles, Rsa(-/-), Rsa(+/+), and Rsa(+/-) in the oral cancer patients was observed as 10.5, 51.1 and 38.4%; whereas normal healthy individuals showed 11.4, 37.1 and 51.4%, respectively. In the informative heterozygous (Rsa(+/-)) oral cancer patients, LOH was infrequent, demonstrated in two of 33 (6%) samples. Thus, the APC gene was infrequently altered by LOH at the polymorphic RsaI locus in exon 11 in the tobacco associated Indian oral cancer, unlike the smoking tobacco/alcohol associated oral cancers from Western countries.  相似文献   

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