CHROMOSOME 17P MAY HARBOR MULTIPLE TUMOR SUPPRESSOR GENES ASSOCIATED WITH PRIMARY GLIOBLASTOMA MULTIFORME

Glioblastoma multiforme (GBM), the most malignant type of glioma, is the most common primary brain neoplasm. Although comprehensive therapeutic measures are applied, the prognosis of GBM remains dismal with a median post-treatment survival of less than one year. Modern molecular genetics has demonstrated that abnormal alterations of tumor suppressor genes (TSGs) and oncogenes are the major mechanisms responsible for the initiation and progression of this malignant tumor. Identifying rela…     

10号染色体可能含有多个与胶质母细胞瘤相关的肿瘤抑制基因

目的 寻找胶质母细胞瘤（GBM）10号染色体上可能存在肿瘤抑制基因的杂合性丢失（LOH）区域,为发现和定位肿瘤抑制基因（TSG）提供线索和依据。方法 应用聚合酶链反应（PCR）方法,采用荧光标记的引物和先进的377型DNA序列自动分析仪,分析了21例GBM10号染色体上20个微卫星多态性标记的LOH。结果 在85．7％（18／21例）GBM的10号染色体上观察到LOH,在57．7％（162／281）可提供信息位点上存在LOH。10q的LOH率高于10p,分别是81．0％（17／21）、66．7％（14／21）。在下列位点或区域检测到较高的LOH率（＞60％）：10q22.3-23.3上的D10s185-D10s192间区域,10p14-15.1上的D10s591-D10s249间区域,10q24.2-26.3上的D10s1693-D10s212间区域,10p12.2-14上的D10s547位点,10q21.3上的D10537位点。结论 10号染色体可能在GBM的分子水平发病机制中发挥着重要作用,它上面的多个染色体区域可能存在与GBM相关的多个TSG。     

显微切割法对肝细胞癌抑癌基因杂合性缺失的研究

目的 通过对肝细胞癌（HCC）抑癌基因（tumor suppressor genes,TSGs)杂合性缺失（loss of heterozygosity,LOH)谱系特点的分析，进一步了解HCC发生过程中多基因变异的特点。方法 采用显微组织切割法从石蜡包埋的组织切片中提取基因组DNA直接测序，对33例信息性HCC进行了6种TSGs(APC、DCC、MCC、OGC1、p53和RBI1）的LOH检测。结果 LOH的总体发生率为36.4％,其中p53:80.0%、OGG1：50.0%、APC：41.7%、RB1:20.0%、DCC:0.0%、MCC:0.0%。结论 在HCC的发生和发展过程中有多基因变异的参与，其中p53、OGG1和APC基因在HCC的发生中起重要作用，RB1的作用次之，而DCC和MCC基因的作用可能较小。     

胶质母细胞瘤染色体10q可能存在多个肿瘤抑制基因

目的寻找胶质母细胞瘤10号染色体长臂(10q)上可能存在肿瘤抑制基因的杂合性缺失(LOH)区域,为发现和定位肿瘤抑制基因提供线索和依据。方法应用聚合酶链反应(PCR)方法分析10例胶质母细胞瘤(GBM)染色体10q上9个微卫星多态性标记的LOH。结果在90%(9/10)肿瘤组织染色体10q上检出LOH,在71%(35/49)可提供信息的位点上观察到LOH。以在10q     

胃癌7号染色体长臂的杂合性缺失分析

目的:检测胃癌患者7号染色体长臂微卫星位点的杂合性缺失(loss of heterozygosity,LOH),以初步确定7号染色体长臂上与胃癌相关基因连锁最密切的微卫星多态位点及LOH的临床意义.方法:在70例原发性胃癌中应用多重PCR技术扩增覆盖整个7号染色体长臂的9个微卫星位点(平均遗传距离为10cm),聚丙烯酰胺凝胶电泳分离PCR产物,用GeneScan、Genotyper软件进行分析.结果:9个微卫星位点的LOH均可发生于原发性胃癌,总的LOH频率为34.3%(24/70),其中D7S486和D7S798位点的LOH频率较高,分别为24.0%(12/50)和19.2%(5/26);总的LOH频率随临床分期而显著增高(P=0.046),D7S486位点的LOH频率在淋巴结转移者显著高于无淋巴结转移者(P=0.015).结论:在7号染色体长臂D7S486和D7S798位点附近,可能存在与胃癌发展相关的抑癌基因.     

精细定位和克隆9p21-22区域内鼻咽癌候选抑瘤基因

目的：进一步精细限定鼻咽癌９p２１－２２区域等位基因杂合性丢失的频率和范围,筛选 和克隆其共同缺失区内鼻咽癌相关的候选抑瘤基因。方法：应用１１个定位于９p２１－２ ２区域的高密度微卫星位点,检测２５例低分化鼻咽癌患者的杂合笥技失,确定其共同缺失区;用ＲＴ－ＰＣＲ和Ｎｏｒｔｈｅｒｎ筛出在鼻咽癌细胞株ＨＮＥ１和鼻咽癌活检组织中表达下调的、定位于共同缺失区内的３’末端ＥＳＴs（Ｅｘｐｒｉｓｓ Ｓｅｑｕｅｎｃ     

原发性肝细胞癌多染色体杂合性丢失研究

研究原发性肝细胞癌（ＨＣＣ）５对染色体３８个位点等位基因杂合性丢失（ＬＯＨ）,ＬＯＨ与肝癌的临床病理改变和肝炎病毒的关系。方法：用ＰＣＲ微卫星多态性分析检测肝癌ＬＯＨ。结果发生高频率ＬＯＨ的位点有染色体１ｐ的Ｄ１Ｓ１８６（这,４８．１％）和Ｄ１Ｓ２４３（１ｐ３６．３,５１．６％）;染色体９ｎ２４的Ｄ９Ｓ５４（６１．８％）,９这的Ｄ９Ｓ１７４７（５２．％）和ＤＤ９Ｓ１７５２（５１．８％）ＷＵＧ ＨＫ     

Two Target Regions of Allelic Loss on Chromosome 9 in Urinary-bladder Cancer

Allelic losses on chromosome 9 are common in a wide variety of human tumors; moreover, two predisposing loci for some inherited cancer syndromes, i.e., familial malignant melanoma and Gorlin syndrome, have been identified on this chromosome. To define the location of putative tumor suppressor genes involved in cancer of the urinary bladder, 85 bladder cancers were examined for allelic loss at 18 microsatellite loci on chromosome 9. Correlations were also sought between loss of heterozygosity on chromosome 9 and several clinicopathological parameters. Allelic loss was observed in 54 of the tumors (64%) and deletion mapping identified two target regions; one at an interval on 9p21 flanked by D9S736 and D9S165, and the other at an interval on 9q31-34 flanked by D9S58 and D9S61. No subtle mutation was detected in the PTCH gene which lies in the latter interval. Allelic loss on chromosome 9 was observed frequently in low grade and non-invasive tumors as well as in tumors of more advanced phenotype. Inactivation of tumor suppressor genes lying in either of two regions of common deletion identified on chromosome 9 might affect carcinogenic mechanisms at an early stage of tumor development in the urinary bladder.     

食管癌组织多种肿瘤抑制基因微卫星多态位点的杂合丢失和不稳定

目的：研究ｐ５３,ｐ１６,Ｒｂ,ＤＣＣ,ＡＰＣ等多种已知抑癌基因在食管癌组织中的缺失及与临床病理的关系。方法：采用ＰＣＲ银染技术,检测高发区３６例配对的食管癌标本１４个微卫星ＤＮＡ多态位点的杂合丢失和不稳定性。结果：分别与ｐ５３,ｐ１６及Ｒｂ连锁的Ｄ１７Ｓ２６１,Ｄ９２Ｓ１６２,Ｄ９２Ｓ１７１,ＩＦＮＡ和Ｄ１３Ｓ１７０均有高频率的杂合丢失;两个以上的位点异常者占８６％,ｐＴＮＭⅢ期患者微卫星ＤＮＡ     

The presence of candidate tumor suppressor gene loci at chromosome 3p for oral squamous cell carcinomas

We investigated the short arm of chromosome 3 (3p) for allelic imbalances, including loss of heterozygosity (LOH) and microsatellite instability (MSI) in 40 primary oral squamous cell carcinomas (SCCs) using 10 microsatellite markers and constructed a deletion map for this chromosome arm. We examined 40 primary tumor tissues, 40 corresponding normal tissues, and seven lymph node metastatic tissues. LOH at one or more loci was found in 24/40 (60%) of tumors. Deletion mapping of these tumors revealed at least three discrete, commonly deleted regions on the chromosome arm. Furthermore, we detected MSI in six of those tested cases (15%). We compared our results with the clinicopathologic features. A number of sites displaying LOH at 3p could be detected in early stage lesions, and the frequencies of LOH tended to be higher in later clinical stages. Thus, the frequent LOH was observed from early stage in pTNM classification. An unknown tumor suppressor gene in the genesis of oral squamous cell carcinoma may exist in 3p.     

Mapping of a Breast Cancer Tumor Suppressor Gene Locus to a 4-cM Interval on Chromosome 18q21

DPC4 and DCC , putative tumor suppressor genes implicated in the genesis of several types of human cancer, lie on the long arm of human chromosome IS. We examined 200 primary breast cancers for allelic losses on chromosome IS, using 15 microsatellite markers distributed along the long arm. Allelic loss was detected most frequently (29–30%) at loci mapped to 18q21. Deletion mapping of the 34 tumors showing partial or interstitial deletions identified a commonly deleted region within the 4-cM interval flanked by D18S474 and D18S487 at 18q21.1-q21.3. Although this interval included the DPC4 and DCC genes, we excluded DPC4 from candidacy when polymerase chain reaction-single-strand conformation polymorphism analysis of each exon failed to detect abnormalities in any of the 54 breast cancers that exhibited loss of heterozygosity involving 18q. Allelic loss on 18q was found more frequently in tumors of the solid tubular histological type (24 of 55, 44%) than in other types (24 of 113, 21%) ( P= 0.0049). The results suggest that a tumor suppressor gene located within the 4-cM region at 18q21, either DCC or another gene not yet identified, may play a role in the development of some sporadic breast cancers, particularly those of the solid tubular type.     

Allelic Loss on Chromosome 9q Is Associated with Lymph Node Metastasis of Primary Breast Cancer

Frequent allelic losses on chromosome 9 are seen in a wide variety of human tumors; moreover, two genes ( P 16 and PTC ) whose mutant alleles confer predispositions to some inherited cancer syndromes have been identified on this chromosome. Using 15 highly polymorphic microsatellite markers distributed on both arms of chromosome 9, we tested 96 primary breast carcinomas for allelic loss in order to define the locations of genes that might be involved in this type of tumor. Allelic loss was observed in 37 of the tumors (39%) and detailed deletion mapping identified target regions at 9p21, 9q22.3 and 9q33. Losses at 9q22.3 and 9q33 were correlated with the presence of lymph node metastasis, and allelic loss at 9q22.3 was observed more frequently in scirrhous tumors than in less aggressive histologic types. Therefore, inactivation of tumor suppressor genes in 9q22.3 and 9q33 regions might play a role in progression of breast cancers, especially in metastasis to lymph nodes and in development of scirrhous tumors.     

Localization of a Target Region of Allelic Loss to a 1-cM Interval on Chromosome 16p.13.13 in Hepatocellular Carcinoma

To identify the location of the putative tumor suppressor gene on chromosome 16p that may be involved in hepatocellular carcinoma (HCC), we examined 96 primary HCCs and evaluated their patterns of allelic loss at 10 microsatellite marker loci distributed along this chromosome arm. Allelic loss at one or more loci was observed in 46 (48%) of these tumors. Through detailed deletion mapping of tumors having partial or interstitial deletions, we identified a commonly deleted region at a 1-cM interval, flanked by D16S519 and D16S3078 at 16p13.13, defining the location of a putative tumor suppressor gene for HCC. This region contains the gene for JAB (JAK-binding protein), which is responsible for negative-feedback regulation of the JAK-STAT pathway induced by cytokine stimulation, raising the possibility that inactivation of this gene may participate in hepatocarcinogenesis via genetic and/or epigenetic changes.     

Chromosome 6 deletion and candidate tumor suppressor genes in adenoid cystic carcinoma

As genomic deletion in chromosome 6 has been implicated in the pathogenesis of adenoid cystic carcinoma (ACC), we assayed 58 paired normal and tumor samples for loss of heterozygosity (LOH) using 38 microsatellite markers spanning chromosome 6. Genetic loss occurred in 57% of cases, with the greatest loss found within a 10cM region flanked by markers D6S471 and D6S1687. Among the heterogeneous histologic subtypes of salivary gland carcinomas, only salivary duct carcinoma had a similar frequency of deletion in this region. This locus contains two major candidate tumor suppressor genes, PLAGL1 and LATS1. We analyzed the sequence of these genes in clinical samples of ACC, but found no tumor-specific mutations. Analysis of gene expression showed no substantial differences between samples of normal salivary gland and ACC, eliminating the most obvious candidate genes in this locus as tumor suppressors in ACC.     

胶质母细胞瘤3号染色体杂合性丢失的研究

目的　寻找胶质母细胞瘤 (GBM) 3号染色体上可能存在肿瘤抑制基因的杂合性丢失 (LOH)区域 ,为发现和定位肿瘤抑制基因 (TSG)提供线索和依据。方法　采用荧光标记的引物和 377型DNA序列自动分析仪 ,分析了 2 0例GBM 3号染色体上 2 3个微卫星多态性标记的LOH。结果　在 50 % (1 0 / 2 0例 )GBM的 3号染色体上观察到LOH ,在 2 5 .6 % (88/ 344)可提供信息位点存在LOH。其中 3q的LOH率明显高于 3p ,3q和 3p的LOH率分别为 50 % (1 0 / 2 0 )、35 % (7/ 2 0 )。在 3q上的下列位点检测到较高的LOH率 :3q2 2 2 3上的微卫星位点D3s1 569(35 .3 % )、3q2 4 2 7上的D3s1 61 4 (42 .9% ) D3s1 565(35 .3 % ) ;在3p1 4 .1 1 4 .3上D3s1 2 89的LOH率也较高 (33 .3 % )。 结论　 3号染色体可能在GBM的分子发病机制中发挥着重要作用 ,3p1 4 .1 1 4 .3上的D3s1 2 89和 3q2 2 2 3上的D3s1 569位点、3q2 4 2 7上的D3s1 61 4 D3s1 565位点间区域可能存在与GBM相关的肿瘤抑制基因     

多种肿瘤抑制基因在视网膜母细胞瘤中存在状态的研究

目的 深入研究视网膜母细胞瘤（ＲＢ）内多种肿瘤抑制基因的存在状态。方法 综合利用ＳＳＣＰ分析、ＤＮＡ序列测定以及多重ＰＣＲ等技术,检测分析ＲＢ肿瘤内Ｒｂ、ｐ５３,ｐ１６,ｐ１５及ｐ１２等肿瘤抑制基因是存在缺失与点突变。结果 约７４％的ＲＢ肿瘤有Ｒｂ基因点突变,１６％显示,ｐ１６基因缺失,但ｐ５３及ｐ２１基因除多态性外未检测到真正的点突变。结论 ＲＢ的发病和病变的进展主要是由于以Ｒｂ基因为核心的代谢     

Detailed Deletion Mapping of Chromosome 9p21-22 in Nasopharyngeal Carcinoma

Previous studies have showed that Epstein-Barr virus (EBV) infection, certain environmental factors and genetic factors were found to be closely associated with nasopharyngeal carcinoma. The rates of NPC in southern China and southeast Asia are 25 times higher than that of in western countries. The statistic analysis revealed 5%-10% NPC patients have family history, there, genetic susceptibility might be an important factor in the pathogenesis of NPC. Unfortunately the alterations of com…     

鼻咽癌全基因组杂合性缺失分析

目的：分析鼻咽癌（nasopharyngeal carcinoma,NPS)全基因组染色体杂合性缺失（loss of heterozygosity,LOH),定位NPC发生高频率LOH的区域,为定位NPC相关基因提供分子遗传学依据。方法：用PCR微卫星多态性分析（335个位点）技术检测98例NPC肿瘤基因组DNA等位基因缺失。结果：在22对染色体中,19对染色体在所选取位点中有至少1个位点LOH频率≥30%,3对染色体（15号,20号和22号）无LOH频率大于30%的位点;在335个位点中,4个位点LOH频率≥60%,其中3个在3号染色体,1个在9号染色体;5个位点LOH频率介于50%-59%,其中3个在3号染色体,5号和11号染色体各1个位点;22个位点LOH频率介于40%-49%,52个位点LOH频率介于30%-39%,轼52个位点LOH频率低于30%,提示为背景缺失;LOH频率≥30%的位点主要集中于12个染色体臂,分布于：1p36-34,3p24-26,3p14-21,3q25-27,4q35-31,5q15-21和5q32-33,8p22-23,9p21-23和9q33-34,11p12-14,11q13-23,13q13-14和13q31-32,14q11-13,14q23-24,14q32。本研究新报道在染色体区带1p,5q和19q等发生高频率LOH,LOH精细图谱提示这些区域内可能存在与NPC相关的TSG。结论：NPC肿瘤细胞在多染色体区带发生高频率LOH是常见的分子事件,提示在这些缺失区,可能存在与NPC发生,发展过程中起重要作用的肿瘤抑制基因。     

Role of chromosomal loss in the progression of prostate cancers

Cytogenetic, molecular cytogenetic, and molecular studies of prostate cancer have produced a large volume of data about chromosomal loci that are aberrant in prostate cancer. The cumulative data on prostate cancer reveal allelic losses on chromosome arms 2q, 3p, 5q, 6q, 7q, 8p, 9p, 10p, 10q, 11p, 11q, 12p, 13q, 16q, 17p, 17q, 18q, and 21q, but there is a great deal of variability between studies. In most cases, the frequency of allelic loss is higher in metastatic tissues or hormone-refractory tumors than in primary tumors. There also seem to be discrepancies in the genetic findings depending on methods employed. Molecular genetic studies, using polymerase chain reaction (PCR) analysis of microsatellite markers, demonstrated allelic loss at 7q31.1, whereas fluorescence in situ hybridization analysis showed a gain at the same region. Com-mon sites of allelic loss that are consistently observed by various methods seem to exist on chromosome arms 8p, 10q, 13q, and 16q. PTEN/MMAC1 has been identified on 10q23.3 and was found to be frequently mutated in advanced prostate cancer. Other regions are also considered to harbor genes associated with the development and progression of prostate cancer, and these could be included in the diagnostic methods for the substaging of prostate cancer. Received: September 22, 2000     

肺鳞癌和肺腺癌中抑癌基因缺失的比较研究

目的 比较中国人肺鳞癌和肺腺癌中抑癌基因丢失的情况,分析抑癌基因在肺癌发生中的不同作用。方法 选取位于13个抑癌基因侧翼（与基因紧密连锁）或位于基因内含子区的22个微卫星位点,对28例肺鳞癌和13例肺腺癌标本进行杂合缺失分析。结果 FHIT、p53、INFNA、VHL和p16基因在肺鳞癌和肺腺癌中均有高频率的杂合缺失,而PRLTS、PTEN和p57基因的杂合缺失率在肺鳞癌和肺腺癌中有明显差异。结论 在肺鳞癌和肺腺癌发病过程中可能有不同的抑癌基因失活,其中PRLTS可能对肺腺癌的发生有重要作用。