肝癌转移抑制基因在8p21.1-23.1染色体上的功能定位

目的:分析人类染色体8p21.1-23.1上肝癌转移抑制基因相关染色体缺失状况,为进一步寻找克隆可能的肝癌转移抑制基因奠定基础.方法:从NCBI的UniSTS数据库查询STS的引物序列,以微细胞杂交克隆DNA为模板(A9/C5F-1和A9/C5F-2为转移不抑制组,A9/C5F-4、A9/C5F-8和A9/C5F-10为转移抑制组)进行STS-PCR扩增.结果:人类染色体8p上D8S552(12786562-12786681),D8S1733(22576582-22576836),D8S1734(22851217-22851336),D8S254(16652480-16652550)及D8S1973(28681110- 28681363)等STS位点所在区域在转移抑制组杂交克隆(A9/C5F-4,A9/C5F-8,A9/C5F-10)存在STS位点的不同程度的获得和转移不抑制组杂交克隆组(A9/C5F-1,A9/C5F-2)STS位点的缺失.结论:D8S552-D8S1973所在的人类染色体8p21.1-23.1区域可能存在肝癌转移抑制基因.     

SLC10A1基因p.S267F位点单核苷酸多态性对慢性乙型肝炎患者肝功能的影响

目的探讨SLC10A1基因p.S267F位点单核苷酸多态性(single nucleotide polymorphisms,SNPs)对慢性乙型肝炎(chronic hepatitis B,CHB)患者肝功能的影响。方法纳入初治CHB患者153例,其中p.S267F位点野生型(C/C)132例,突变型(C/T)21例。T检验比较p.S267F位点野生型与突变型CHB患者各项肝功能指标间的差异。结果 SLC10A1基因p.S267F位点突变型CHB患者的ALT、AST、TBIL和DBIL水平均显著低于野生型患者(P0.05);两组患者ALP、GGT和TBA水平间的差异无统计学意义(P0.05)。结论 SLC10A1基因p.S267F位点突变型CHB患者的肝功能损伤程度低于野生型CHB患者,SLC10A1基因p.S267F位点突变可能是CHB患者肝损加重的保护因素。     

肝癌患者血浆循环DNA杂合性缺失的检测及其临床意义

目的检测HCC患者血浆循环DNA杂合性缺失（LOH），并探讨将其作为有关临床预测标记的可能性。方法选择位于染色体8p上3个具有高度多态性的微卫星标记D8S277、D8S298和D8S1771，对62份HCC患者血浆循环DNA进行LOH检测，并进一步探讨LOH与患者HBsAg表达、是否肝硬化、血清AFP水平、肿瘤大小及细胞分化程度和有无肝内转移等临床病理特征之间的关系。结果在62份HCC患者血浆循环DNA标本中，36份（58．1％）在1个或多个位点发生LOH，D8S277、D8S298和D8S1771位点杂合度分别为74．2％（46／62）、75．8％（47／62）和69．4％（43／62），LOH频率分别为32．6％（15／46）、44．7％（21／47）和46．5％（20／43）。D8S298位点有肝内转移患者血浆循环DNA标本的LOH频率（62．5％）明显高于无肝内转移者（26．1％），差异有统计学意义（P〈0．05）；其他临床病理特征与3个位点上的LOH频率无明显相关。结论血浆循环DNA中D8S298位点LOH有可能成为HCC术后转移复发及预后的一个潜在的预测标记。     

浸润性乳腺癌及乳腺增生细胞3p、9p上5个微卫星位点的杂合性缺失观察

目的探讨乳腺浸润性导管癌及乳腺增生细胞中染色体3p、9p上5个微卫星位点（MS）杂合性缺失（LOH）模式。方法显微分离技术分离病变细胞,PCR．微卫星技术分析18例乳腺单纯性导管增生（UDH组）、15例不典型导管增生（ADH组）和35例乳腺浸润性导管癌（IDC组）细胞的3p、9p上D3S1447、D3S1612、D3S1597、D9S171及D9S1748位点的LOH模式。结果UDH组中仅1例D3S1447位点发生LOH（10％）,ADH组5个位点均发生一定频率的LOH（10％-22％）,IDC组5个位点均发生高频LOH（19％～48％）。至少1个位点发生LOH者,UDH组为6％、ADH组为33％、IDC组为71％,三组相比,P〈0．05;2个或以上位点发生LOH者,UDH组为0、ADH组为13％、IDC组为40％,UDH组、ADH组与IDC组相比,P均〈0．05。IDC组中D3S1612发生高频LOH者在有淋巴结转移组为63％,无淋巴结转移组为19％,两组相比,P〈0．05。结论UDH组的D3S1447位点发生的LOH和ADH组的5个位点发生的LOH有作为癌变风险预测分子标记的可能性,分析多个MS的LOH模式对于乳腺癌的早期预测和早期诊断有一定参考价值,D3S1612位点的LOH可能是IDC发生淋巴结转移的重要分子机制。     

山东省原发性高血压1号染色体基因扫描

目的对原发性高血压患者及正常对照者的1号染色体进行扫描，查找与原发性高血压关联的遗传位点。方法在1号染色体上间隔10cM遗传距离选择31个微卫星遗传位点，用DNA混合池的方法对原发性高血压患者450例和正常对照者450例的DNA样本进行基因扫描。采用CLUMP软件对患者组和对照组每个位点的等位基因频率进行比较。结果在D1S196位点（1q24．2）、D1S249位点（1q32）和D1S2667位点（1p36．22）发现患者组与对照组的等位基因频率存在显著性差异（P〈0．01）。结论山东省原发性高血压患者在1号染色体的D1S196、D1S249与D1S2667位点附近可能存在原发性高血压易感基因，需要进行候选基因突变筛查。     

HCV p7蛋白反式调节基因p7TP2的克隆化及生物信息学分析

目的:克隆HCV p7蛋白反式调节未知功能新基因p7TP2,构建其真核表达载体,并应用生物信息学初步探讨其结构及功能．方法:应用PCR技术从HepG2细胞提取的 cDNA扩增p7TP2基因,选用pGEM-T载体进行TA克隆,通过PCR,限制性酶切分析及测序进行鉴定,再将其亚克隆到真核表达载体 pcDNATM3．1／myc-His A,通过PCR,限制酶切分析进行鉴定,并应用生物信息学初步分析其物理化学性质、蛋白质结构域、功能及染色体定位．结果:成功从HepG2细胞提取的cDNA中扩增出p7TP2基因,编码区为495核苷酸(nt),编码产物为164氨基酸残基(aa),经核苷酸序列数据库(GenBank)同源序列的搜寻,与已知基因序列和蛋白序列之间没有显著同源性,属于未知功能新基因,并成功进行TA克隆,酶切、测序均正确,并进一步亚克隆至pcDNATM3．1／ myc-His A真核表达载体,生物信息学分析此基因位于8q24．3,Mr17 146．5,理论pI:9．26,半衰期为30 h(体外哺乳类网状细胞),属于不稳定蛋白,疏水指数较高,含有潜在的三个螺旋区域,四个β折叠,四个蛋白激酶C磷酸化位点, 一个酪蛋白激酶Ⅱ磷酸化位点,5个N-肉豆蔻酰位点,预测可能为具有不紧密的球蛋白结构,具有信号肽及两个跨膜结构域．结论:发现了HCV p7反式调节新的靶基因, 构建了pcDNATM3．1／myc-HisA真核表达载体．     

DLC-1基因表达与肝细胞癌复发转移的关系

目的已报道人类染色体8p缺失可能与肝癌转移有关,本文应用实时定量聚合酶链反应(RQ- PCR)研究位于8p的DLC-1基因mRNA表达与肝细胞癌侵袭转移的关系。方法收集51例复旦大学中山医院外科手术切除的肝细胞癌(HCC)及癌旁正常组织标本,根据临床病理学指标,分为高低侵袭性两组,用RQ-PCR对不同侵袭性HCC之间的DLC-1基因表达进行分析。对不同侵袭转移潜能MHCC97-L、MHCC97-H、HCCLM3、Hep3B及HepG2肝癌细胞系用同样方法分析DLC-1基因的表达差异。结果非转移细胞系Hep3B和HepG2与转移细胞系MHCC97-L、MHCC97-H和HCCLM3之间DLC—1基因表达差异有统计学意义(P相似文献   

不同转移潜能的小鼠肝癌淋巴道转移和淋巴管生成的研究

目的探讨小鼠淋巴道高、低转移潜能的肝癌细胞的体内淋巴道转移状况和淋巴管生成对淋巴道转移的影响。方法将淋巴道高、低转移潜能的肝癌细胞接种于Balb／C小鼠，观察成瘤及转移情况，对肿瘤组织进行淋巴管染色，观察淋巴管生成情况。另取高、低转移潜能的细胞株进行体外淋巴管生成实验并进行小鼠肿瘤转移基因芯片检测，对血管内皮细胞生长因子C、D（VEGF—C、D）进行半定量逆转录聚合酶链反应及实时定量聚合酶链反应分析。结果高，低转移细胞在小鼠髂总动脉旁、肾门淋巴结的转移差异有统计学意义（P=0．0l8）。高转移潜能组诱导淋巴管生成的数量大于低转移组和对照组（P=0．032）。高转移组的CD44、E-cadherin．HER2／neu、H—Ras．VEGF—C的表达均高于低转移组，nm23A．nm23-E4、pl6ink4a、CD61等均低于低转移组。半定量逆转录聚合酶链反应表明，高转移组vEGF—C高于低转移组，VEGF—D低于低转移组。实时定量聚合酶链反应分析高转移组的VEGF—D分泌显著小于低转移组，vEGF—C／VEGF—D在高转移组明显高于低转移组。结论肝癌的淋巴道转移与淋巴管生成有关，VEGF—C、D相关基因表达的改变影响淋巴管生成。VEGF—C／VEGF—D比值可能是有效判断并影响肝癌淋巴道转移潜能的指标之一。     

急性白血病p16基因微卫星不稳定性及杂和性缺失的研究

目的分析急性白血病（AL）患者p16基因连锁的微卫星不稳定性（MSI）和杂和性缺失（LOH），了解p16基因改变与AL发生的关系。方法采用多重PCR方法检测53例AL患者骨髓及口腔黏膜细胞标本的p16基因连锁的3个微卫星位点（D9S162、D9S1748、D9S171），观察其MSI及LOH情况。结果53例AL患者中，MSI检出率为43．4％（23／53）；位于9p21的p16基因连锁的微卫星D9S162、D9S1748、D9S171的LOH发生率分别为0（0／53）、5．7％（3／53）和9．4％（5／53），MSI发生率分别为13．2％（7／53）、7．6％（4／53）和7．6％（4／53）。结论AL患者p16基因连锁微卫星均可检测到高频率的MSI和LOH，说明p16基因突变与AL发生、发展有关。     

部分基因组扫描研究2型糖尿病易感基因座位的初步报告

目的　通过部分基因组扫描筛查与 2型糖尿病连锁的位点 ,为进一步定位和克隆 2型糖尿病的易感基因奠定基础。方法　采用以微卫星DNA标记为基础的荧光标记 半自动基因组扫描技术 ,应用Perkin Elmer的试剂盒 (ABIPrismLinkageMappingSetVersion 2 ) ,共 6 3对引物 ,研究 2型糖尿病家系 5 8个 ,共 2 6 4份样品 ,其中糖尿病患者 15 2人 ,非糖尿病患者 112人 ,有同胞关系的患者74人 ,组成 45对患病同胞对 ,对 1号、12号、18号、2 0号染色体进行部分基因组扫描。连锁分析采用GENEHUNTERversion 2连锁分析软件包。结果　非参数连锁分析结果提示 ,1号染色体 1p31区域的D1S2 86 8位点同 2型糖尿病连锁 ,其NPL值为 1.192 ,P值为 0 .0 45 ,2 0号染色体短臂末端 2 0 p13区域的位点D2 0S117和D2 0S889以及 2 0号染色体长臂 2 0q13 .3区域的D2 0S196位点同 2型糖尿病连锁 ,其NPL值分别为 1.36 2、1.36 0、1.199,P值分别为 0 .0 30、0 .0 30和 0 .0 49。结论　 1号染色体短臂 1p31区域及 2 0号染色体短臂 2 0 p13区域及长臂 2 0 q13.3区域可能存在有 2型糖尿病的易感基因。     

Complementation of a DNA repair defect in xeroderma pigmentosum cells by transfer of human chromosome 9.

Complementation of the repair defect in xeroderma pigmentosum cells of complementation group A was achieved by the transfer of human chromosome 9. A set of mouse-human hybrid cell lines, each containing a single Ecogpt-marked human chromosome, was used as a source of donor chromosomes. Chromosome transfer to XPTG-1 cells, a hypoxanthine/guanine phosphoribosyltransferase-deficient mutant of simian virus 40-transformed complementation group A cells, was achieved by microcell fusion and selection for Ecogpt. Chromosome-transfer clones of XPTG-1 cells, each containing a different human donor chromosome, were analyzed for complementation of sensitivity to UV irradiation. Among all the clones, increased levels of resistance to UV was observed only in clones containing chromosome 9. Since our recipient cell line XPTG-1 is hypoxanthine/guanine phosphoribosyltransferase deficient, cultivation of Ecogpt+ clones in medium containing 6-thioguanine permits selection of cells for loss of the marker and, by inference, transferred chromosome 9. Clones isolated for growth in 6-thioguanine, which have lost the Ecogpt-marked chromosome, exhibited a UV-sensitive phenotype, confirming the presence of the repair gene(s) for complementation group A on chromosome 9.     

Expression of an X-linked gene from an inactive human X chromosome in mouse-human hybrid cells: further evidence for the noninactivation of the steroid sulfatase locus in man.

Somatic cell hybrid clones were derived from the fusion of hypoxanthine phosphoribosyltransferase (HPRT; EC 2.4.2.8)-deficient mouse cells and two different human fibroblast strains, each carrying an X chromosome-autosome translocation. One of these had an X/11 translocation [46,X,t(X;11)(p21;q13)] and the other had an X/19 translocation [46,X,t(X;19)(q22;q13)]. The structurally normal human X chromosome is the late-replicating (genetically inactive) chromosome in these two cell strains; the rearranged X chromosome is early replicating (genetically active). One primary hybrid clone carrying both the translocated X chromosome and the structurally normal X chromosome was isolated in hypoxanthine/aminopterin/thymidine medium from each of these two cell fusion experiments. These clones were then selected in medium containing 8-azaguanine to achieve the loss of the active human HPRT locus. Five subclones from the cell hybrid with the X/11 translocation failed to express two known human X-chromosome markers [glucose-6-phosphate dehydrogenase (G6PD; EC 1.1.1.49) and phosphoglycerate kinase (PGK; EC 2.7.2.3)] but did express human microsomal steroid sulfatase (STS; sterol-sulfate sulfohydrolase, EC 3.1.6.2). Three of these were cytogenetically analyzed and found to contain a structurally normal human X chromosome but not the X/11 translocation. Two subclones were isolated in 8-azaguanine from the hybrid with the X/19 translocation. Cytogenetic analysis of these two clones showed the presence of a structurally normal human X chromosome; the X/19 translocation was not present. They did not express human G6PD, PGK, or HPRT but did express human STS. These results indicate that human STS is expressed from a locus on the inactive human X chromosome and support our earlier finding that the STS locus escapes X-inactivation in man.     

A detailed physical map of the horse Y chromosome

We herein report a detailed physical map of the horse Y chromosome. The euchromatic region of the chromosome comprises approximately 15 megabases (Mb) of the total 45- to 50-Mb size and lies in the distal one-third of the long arm, where the pseudoautosomal region (PAR) is located terminally. The rest of the chromosome is predominantly heterochromatic. Because of the unusual organization of the chromosome (common to all mammalian Y chromosomes), a number of approaches were used to crossvalidate the results. Analysis of the 5,000-rad horse x hamster radiation hybrid panel produced a map spanning 88 centirays with 8 genes and 15 sequence-tagged site (STS) markers. The map was verified by several fluorescence in situ hybridization approaches. Isolation of bacterial artificial chromosome (BAC) clones for the radiation hybrid-mapped markers, end sequencing of the BACs, STS development, and bidirectional chromosome walking yielded 109 markers (100 STS and 9 genes) contained in 73 BACs. STS content mapping grouped the BACs into seven physically ordered contigs (of which one is predominantly ampliconic) that were verified by metaphase-, interphase-, and fiber-fluorescence in situ hybridization and also BAC fingerprinting. The map spans almost the entire euchromatic region of the chromosome, of which 20-25% (approximately 4 Mb) is covered by isolated BACs. The map is presently the most informative among Y chromosome maps in domesticated species, third only to the human and mouse maps. The foundation laid through the map will be critical in obtaining complete sequence of the euchromatic region of the horse Y chromosome, with an aim to identify Y specific factors governing male infertility and phenotypic sex variation.     

The microcell mediated transfer of human chromosome 8 into highly metastatic rat liver cancer cell line C5F

AIM: Our previous research on the surgical samples of primary liver cancer with CGH showed that the loss of human chromosome 8p had correlation with the metastatic phenotype of liver cancer. In order to seek the functional evidence that there could be a metastatsis suppressor gene(s) for liver cancer on human chromosome 8, we tried to transfer normal human chromosome 8 into rat liver cancer cell line C5F, which had high metastatic potential to lung. METHODS: Human chromosome 8 randomly marked with neo gene was introduced into C5F cell line by MMCT and positive microcell hybrids were screened by double selections of G418 and HAT. Single cell isolation cloning was applied to clone microcell hybrids. Finally, STS-PCR and WCP-FISH were used to confirm the introduction. RESULTS: Microcell hybrids resistant to HAT and G418 were obtained and 15 clones were obtained by single-cell isolation cloning. STS-PCR and WCP-FISH proved that human chromosome 8 had been successfully introduced into rat liver cancer cell line C5F. STS-PCR detected a random loss in the chromosome introduced and WCP-FISH found a consistent recombination of the introduced human chromosome with the rat chromosome. CONCLUSION: The successful introduction of human chromosome 8 into highly metastatic rat liver cancer cell line builds the basis for seeking functional evidence of a metastasis suppressor gene for liver cancer harboring on human chromosome 8 and its subsequent cloning.     

Genome-wide analyses on loss of heterozygosity in hepatocellular carcinoma in Southern China

BACKGROUND/AIMS: To conduct a genome-wide analysis of loss of heterozygosity (LOH) and its clinical significance in hepatocellular carcinoma (HCC) in Southern China where high incidence of HCC was documented. METHODS: LOH of 382 microsatellite loci on all autosomes were detected with polymerase chain reaction-based microsatellite polymorphism analyses in 104 HCC tumor tissues. RESULTS: High frequency of LOH (>55.7%) was observed on chromosome 1p, 1q, 2q, 3p, 4q, 6q, 8p, 9p, 13q, 16q, and 17p. LOH rates on loci D4S2964 (4q21.21), D8S277 (8p23.1-pter) and D17S938 (17p13.1-p13.3) were significantly higher in cases with positive HBsAg than in those with negative HBsAg. Similarly, LOH on loci D1S214 (lp36.3), D1S2797 (1p34) and D3S3681 (3p11.2-p14.2) were more frequently detected in tumors with intrahepatic metastasis than in those without. CONCLUSIONS: Status of LOH in HCC in Southern China is similar to that reported previously in other countries and areas. However, we firstly identified high-frequency LOH on chromosome 3p in HCC. Furthermore, HBV infection, as well as tumor intrahepatic metastasis, may be correlated with allelic losses on certain chromosome regions.     

Similar regions of human chromosome 3 are eliminated from or retained in human/human and human/mouse microcell hybrids during tumor growth in severe combined immunodeficient (SCID) mice

By passaging microcell hybrids (MCHs) containing human chromosome 3 (chr3) on A9 mouse fibrosarcoma background through severe combined immunodeficient (SCID) mice (elimination test), we have previously defined a 1-Mb-long common eliminated region 1 (CER1) at 3p21.3, a second eliminated region (ER2) at 3p21.1-p14 and a common retained region (CRR) at 3q26-qter. In the present work, chr3 was transferred by microcell fusion into the human nonpapillary renal cell carcinoma line KH39 that contained uniparentally disomic chr3. Four MCHs were generated. Compared with KH39, they developed fewer and smaller tumors, which grew after longer latency periods in SCID mice. The tumors were analyzed in comparison with corresponding MCHs by chr3 arm-specific painting, 19 fluorescent in situ hybridization (FISH) probes, and 27 polymorphic markers. Three MCHs that maintained the intact exogenous chr3 in vitro lost one 3p copy in all 11 tumors. Seven of 11 tumors lost the exogenous 3p, whereas four tumors contained mixed cell populations that lacked either the exogenous or one endogenous KH39 derived 3p. In one MCH the exogenous chr3 showed deletions within CER1 and ER2 already in vitro. It remained essentially unchanged in 8/9 derived tumors. The third, exogenous copy of the 3q26-q27 region (part of CRR) was retained in 16/20 tumors. It can be concluded that the human/human MCH-based elimination test identifies similar eliminated and retained regions on chr3 as the human/murine MCH-based test.     

Cytogenetic and molecular studies on a recombinant human X chromosome: implications for the spreading of X chromosome inactivation.

A pericentric inversion of a human X chromosome and a recombinant X chromosome [rec(X)] derived from crossing-over within the inversion was identified in a family. The rec(X) had a duplication of the segment Xq26.3----Xqter and a deletion of Xp22.3----Xpter and was interpreted to be Xqter----Xq26.3::Xp22.3----Xqter. To characterize the rec(X) chromosome, dosage blots were done on genomic DNA from carriers of this rearranged X chromosome using a number of X chromosome probes. Results showed that anonymous sequences from the distal end of the long arm to which probes 4D8, Hx120A, DX13, and St14 bind as well as the locus for glucose-6-phosphate dehydrogenase (G6PD) were duplicated on the rec(X). Mouse-human cell hybrids were constructed that retained the rec(X) in the active or inactive state. Analyses of these hybrid clones for markers from the distal short arm of the X chromosome showed that the rec(X) retained the loci for steroid sulfatase (STS) and the cell surface antigen 12E7 (MIC2); but not the pseudoautosomal sequence 113D. These molecular studies confirm that the rec(X) is a duplication-deficiency chromosome as expected. In the inactive state in cell hybrids, STS and MIC2 (which usually escape X chromosome inactivation) were expressed from the rec(X), whereas G6PD was not. Therefore, in the rec(X) X chromosome inactivation has spread through STS and MIC2 leaving these loci unaffected and has inactivated G6PD in the absence of an inactivation center in the q26.3----qter region of the human X chromosome. The mechanism of spreading of inactivation appears to operate in a sequence-specific fashion. Alternatively, STS and MIC2 may have undergone inactivation initially but could not be maintained in an inactive state.     

Introduction of a human X-6 translocation chromosome into a mouse teratocarcinoma: investigation of control of HLA-A, B, C expression.

We have developed an approach to human developmental biology which exploits somatic cell genetics. With this system we have examined the production of the HLA-A,B,C antigens, A human-mouse somatic cell hybrid was constructed which contained a human X-7 chromosome translocation carrying the HLA region; this hybrid was used as a donor of the X-6 translocation in the technique of microcell transfer. The X-6 chromosome recipient was the mouse embryonal carcinoma cell line PCC4. The microcell hybrid MCP-6 retained the embryonal carcinoma phenotype as judged by shape and absence of H-2 expression. Nonetheless, the expression of the HLA-A,B,C genes was not extinguished. HLA-A,B,C antigen production of the cell surface, however, was not detected because this hybrid apparently could not make beta 2-microglobulin.     

Assignment of the gene for methylthioadenosine phosphorylase to human chromosome 9 by mouse-human somatic cell hybridization.

The purine and polyamine metabolic enzyme methylthioadenosine (MeSAdo) phosphorylase is abundant in normal cells and tissues but is lacking from many human and murine malignant cell lines and from cells of some human leukemias in vivo. To explore the genetic control of MeSAdo phosphorylase expression, we measured levels of the enzyme in somatic cell hybrids prepared by fusing MeSAdo phosphorylase-deficient mouse L cell lines with human fibroblasts. In the hybrid clones, MeSAdo phosphorylase activity segregated concordantly with adenylate kinase 1, a marker for human chromosome 9, but not with enzyme markers for any other human chromosome. In hybrid clones derived from human fibroblasts with a reciprocal translocation between chromosomes 9 and 17, MeSAdo phosphorylase activity was confined to cells containing the 9pter----9q12 region. In every case, the enzyme-positive hybrid clones displayed bands of MeSAdo phosphorylase activity with isoelectric points characteristic of both the human and murine enzymes. These results indicate that the structural gene for human MeSAdo phosphorylase, designated MTAP, can be assigned to the 9pter----9q12 region of human chromosome 9. Furthermore, these studies with interspecies somatic cell hybrids show that the MeSAdo phosphorylase-deficient state is recessive in mouse L cell lines.