Identification of a novel single nucleotide polymorphism (SNP) in the human organic cation transporter-like 2-antisense (ORCTL2S) gene

We found a single nucleotide polymorphism (SNP) in exon 3 of the human organic cation transporter-like 2-antisense (ORCTL2S) gene: a base substitution A266G which was confirmed by direct sequencing. Heterozygosity of the polymorphic alleles was 0.45 in a Japanese population. This polymorphism will be useful in the allelic expression analysis of the ORCTL2S gene. Received: September 13, 1999 / Accepted: September 27, 1999     

弓首蛔虫及狮弓蛔虫线粒体基因组nad4基因多态性研究

目的比较犬、猫常见蛔虫的线粒体DNA(mtDNA)中烟酰胺脱氢酶亚基Ⅳ基因(nad4)部分序列(pnad4),以期找出它们之间的序列差异和种群遗传关系。方法抽提61个弓首属蛔虫(包括犬弓首蛔虫、猫弓首蛔虫、马来西亚弓首蛔虫和犊弓首蛔虫)和狮弓蛔虫虫体的总DNA,用PCR方法扩增mtDNApnad4,然后用SSCP技术和DNA测序对序列进行分析研究。结果犬弓首蛔虫种群内pnad4的序列差异为1.17%,与猫弓首蛔虫、马来西亚弓首蛔虫、牛弓首蛔虫和狮弓蛔虫种间的平均序列差异分别为13.92%、16.48%、15.12%和20.32%。猫弓首蛔虫种群内pnad4的序列差异为1.00%,与马来西亚弓首蛔虫、牛弓首蛔虫、狮弓蛔虫平均序列差异分别是17.90%、13.55%和18.50%。马来西亚弓首蛔虫种群内pnad4序列差异为0.13%,与牛弓首蛔虫、狮弓蛔虫序列差异分别为13.50%和20.60%。结论犬弓首蛔虫不同地方虫株的pnad4有一定差异,猫弓首蛔虫种群内差异较小,马来西亚弓首蛔虫种群内差异很小。弓首属各虫种之间的差异以及与狮弓蛔虫的差异都较大。马来西亚弓首蛔虫pnad4序列与其它虫种差异都较大,证明它确为一独立种。pnad4序列是弓首蛔虫和狮弓蛔虫理想的种特异的遗传标记。     

Identification of two SNPs in myostatin (MSTN) gene of Takifugu rubripes and their association with growth traits

The myostatin (MSTN) is a member of transforming growth factor-β superfamily which inhibits muscle growth. In this study, the genomic DNA sequence of MSTN gene was cloned from Takifugu rubripes (T. rubripes). Two polymorphisms of the MSTN gene were detected by polymerase chain reaction-single strand conformation polymorphism (PCR–SSCP) and DNA sequencing methods in 296 T. rubripes. One A748G locates in exon 2 and the other, C1197T, in intron 2. Analysis showed that the A748G mutation caused an amino acid change from Thr to Ala (Ala166Glu). These two SNPs showed a low degree of linkage disequilibrium and four haplotypes were identified. The most frequent haplotype was AC, which occurred at a frequency of 44.3%. Association analyses between these two SNPs and growth traits showed that the individuals with genotype CT and TT of the mutation C1197T had significantly higher body mass, body length and body height than those with genotype CC (P < 0.05). These results show that MSTN gene can be utilized as a candidate gene for molecular marker-assisted breeding of T. rubripes.     

HLA-B*07 allele frequencies and haplotypic associations in Koreans

We have investigated the frequencies of HLA-B*07 alleles and their haplotypic associations with HLA-A, -C and -DRB1 loci in 489 healthy unrelated Koreans, including 214 parents from 107 families. All of the 45 samples (9.2%) typed as B7 by serology were analyzed for B*07 alleles using polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) method. Two different B*07 alleles were detected: B*0702 (allele frequency 0.041) and B*0705 (0.005). Two characteristic haplotypes showing strong linkage disequilibrium in Koreans were A*2402-Cw*07-B*0702-DRB1*0101 (haplotype frequency 0.028) and A*2901-B*0705-DRB1*0803 (0.005). The characteristic haplotype A*2901-B*0705-DRB1*0803, found in 100% (5/5) of B*0705-positive individuals, has not been previously described in other ethnic groups. HLA-B7 alleles comprise distinctive extended haplotypes in the Korean population. The probability of HLA-B7 allele mismatches among ABDR-matched unrelated donor-recipient pairs is expected to be low in Koreans.     

溃疡性结肠炎及结肠直肠癌与P53基因改变的关系

目的:为了解P53抑癌基因在溃疡性结肠炎、结肠直肠癌及癌旁组织中的改变状况,进而探讨其中癌变过程中所起的作用。方法:采用改进的非同位素PCR-SSCP方法对21例溃疡性结肠炎、19例结肠直肠癌(CRC)及癌旁组织P53基因第5、6外显子(Exon 5.6)进行检测,并应用DNA测序技术对PCR-SSCP阳性标本进行进一步测定。结果:21例溃疡性结肠炎组织中有6例检出P53基因改变,19例CRC组织中有7例检出P53基因点突变,2例DNA缺失;19例CRC癌旁组织6例检出P53基因P53点突出未检出DNA缺失。结论:P53基因改变在CRC及癌旁组织存在较为普遍,而在溃疡性结肠炎也有一定的检出率,表明P53基因改变在溃疡性结肠炎相关性结肠直肠癌(UCACRC)是早期事件,并可能是UCACRC的发病原因之一。     

食管鳞状上皮细胞癌中P53基因突变的PCR-SSCP检测

应用PCR－SSCP银染技术检测了40例食管鳞状细胞癌p53基因第5、6、7和第8外显于的突变情况。结果显示：13例（32．5％）有p53基因突变，突变主要发生在第5和第8外显子，与癌分化程度无明显关系，但伴淋巴结癌转移病例中p53基因的突变率明显高于无转移者（P＜0．05）。本研究提示，p53基因突变存在于中、晚期食管癌中，并可能与食管鳞癌的进展与转移有关。     

PCR-SSCP法检测非小细胞肺癌中FADD基因突变的研究

目的检测Fas相关死亡结构域蛋白(Fasassociateddeathdomainprotein,FADD)基因在人非小细胞肺癌(nonsmallcelllungcancer,NSCLC)中的突变情况,以探讨该基因在肺癌发生发展中的作用及机制。方法采用聚合酶链反应-单链构象多态性分析(polymerasechainreactionandsinglestrandconformationpolymorphism,PCRSSCP)检测74例NSCLC原发灶癌组织及13例癌旁正常肺组织中FADD基因突变情况。结果74例NSCLC组织中检出5例发生FADD基因突变,FADD基因突变与癌的淋巴结转移呈显著正相关(rs=0.378,P=0.001),与其他临床病理特征无关。结论NSCLC中存在着FADD基因突变。FADD基因突变在NSCLC的发生发展中可能起着重要作用。     

Glassy cell carcinoma of the uterine cervix: report of two cases with genetic analysis

Glassy cell carcinoma, a rare cervical malignancy, is a specific type of poorly differentiated adenosquamous carcinoma. Because of the rarity of such tumors, the genetic alterations associated with their development remain unclear. In this study we investigated the possible integration of human papillomavirus and genetic alterations in the p53 tumor-suppressor gene and in ras oncogenes in two patients with this tumor. The genomic DNA of human papillomavirus type 18 was detected by polymerase chain reaction in both tumors. One of the tumors was also positive for the genomic DNA of human papillomavirus type 16. In addition, a mutation in exon 5 of the p53 gene was identified in both tumors, while no mutations were found in the various ras genes examined. Mutation of the p53 gene together with infection by human papillomavirus appears to participate in the tumorigenesis of glassy cell carcinoma. Received: August 2, 1999 / Accepted: November 26, 1999     

p53基因突变对非小细胞肺癌TSG101/MDM2信号通路的影响

目的探讨p53基因突变在肺癌中对TSG101/MDM2信号通路影响的临床病理学意义。方法采用免疫组织化学方法检测185例肺癌组织标本中TSG101、MDM2及p53的表达,用聚合酶链反应单链构象多态性(Polymerase Chain Reaction ,single-strand conformation polymorphism, PCR-SSCP)分析法检测p53突变情况,以及Western blot检测TSG101在肺癌组织和正常肺组织中的表达。结果（1）肺癌组中p53蛋白的总阳性率为80.54%(149/185),PCR-SSCP检测结果显示总突变率为56.67%（17/30）,p53蛋白表达与病理分期、淋巴结转移有相关性（P<0.05）;TSG101蛋白的低表达率为58.92%(109/185),Western blot结果显示TSG101在癌组织中的表达明显低于对照组（P<0.05）,TSG101蛋白表达与病理分期、分化、淋巴结转移有相关性（P<0.05）;MDM2蛋白的过表达率为77.84%(144/185),MDM2蛋白表达与病理分期、淋巴结转移有相关性（P<0.05）。(2)在p53阳性的149例中TSG101阳性76例,MDM2阳性139例,在p53阴性的36例中TSG101阳性33例,MDM2阳性5例。p53与TSG101两者共表达率为41.08%,一致性为42.70%。p53与MDM2两者共表达率为75.14%,一致性为91.89%。结论（1）p53/MDM2上调与TSG101表达下调肺癌的发生及生物学行为有关。(2)当p53突变时, TSG101与MDM2的表达呈负相关关系。     

人类白血病P53基因异常的研究

以多聚酶链反应-单链构象多态性(PCR-SSCP)分析31例不同类型的白血病P53抗癌基因点突变,16例急性粒细胞白血病中有1例,6例慢粒性细胞白血病中有1例发生 P53基因扩增片段泳动变位,提示 P53抑癌基因点突变导致功能失活,这与白血病的发病可能存在某种关系。