比较基因组杂交研究瘢痕疙瘩遗传变异

目的 了解瘢痕疙瘩遗传学改变的特征。方法 应用比较基因组杂交技术研究6例瘢痕疙瘩基因组的不平衡即遗传物质的丢失或扩增情况。结果 瘢痕疙瘩出现高频率的DNA拷贝数缺失的染色体是1p(66．7％)、16号染色体(83．3％)、20号染色体(83．3％)、22号染色体(83．3％)，其最小重叠区分别为1pter-32．2、16p13．2-p11．1、20q11．1-q13．2、16p13．2-p11．1，未发现特异区域的DNA拷贝数的高频率扩增。结论 1p、16号染色体、20号染色体、22号染色体极可能存在相关的瘢痕疙瘩抑制基因，这些基因的丢失可能参与了瘢痕疙瘩的发生、发展。     

比较基因组杂交研究原发性胃癌的遗传学变异

目的研究原发性胃癌发生、发展过程中遗传学变异情况。方法采用比较基因组杂交分析23例原发性胃癌基因组DNA拷贝数变化情况。结果原发性胃癌患者平均每例肿瘤染色体臂变化数为7.52,扩增数要明显多于丢失数(5.38∶2.14)。DNA拷贝数扩增常见于8q(9/21,42.9%)、20q(9/21,42.9%)、17q(8/21,38.1%)、3q(7/21,33.3%)、7q(7/21,33.3%)、11q(6/21,28.6%)、13q(6/21,28.6%)、1q(5/21,23.8%)、20p(5/21,23.8%);DNA拷贝数缺失常见于17p(7/21,33.3%)、18q(6/21,28.6%)、5q(5/21,23.8%)、8p(5/21,23.8%)、9p(5/21,23.8%)。结论原发性胃癌中存在多条染色体拷贝数的变化,由此引起相应癌基因的扩增和抑癌基因的丢失可能参与了胃癌的发生和发展。     

原发性胆囊癌染色体比较基因组杂交分析

目的 探讨原发性胆囊癌组织中的基因组变化，寻找与胆囊癌相关的癌基因和抑癌基因的染色体候选区域。方法 采用比较基因组杂交方法（CGH）分析28例原发性胆囊癌组织基因组的不平衡即DNA的扩增和丢失。结果 胆囊癌常见的染色体扩增区域是7p、7q、8q、17q、5p、11q、1q；常见的缺失染色体为17p、9p、5q、6q、3p、15p、13p。结论 胆囊癌中存在多条染色体拷贝数的改变，7p、7q、8q和17p、9p等部位可能分别存在与胆囊癌密切相关的癌基因和抑癌基因。     

比较基因组杂交检测散发性结直肠癌染色体变异的临床意义

目的了解散发性结直肠癌（SCRC）的染色体变异及其与SCRC临床病理特征的关系。方法采用比较基因组杂交（CGH）技术检测40例SCRC的染色体变异情况,分析其与临床病理特征的关系。结果40例SCRC患者CGH检测结果显示．所有病例均有不同程度的染色体臂发生扩增或丢失,平均每例变异数为7．55,扩增数为4．73,丢失数为2．83。染色体扩增区域有20q、12q、13q、7P、7q和16q;缺失区域有18q、5q、4q、8P和17P。结直肠癌TNM分期中Ⅲ、Ⅳ期患者的染色体总变异数和扩增数、缺失数均高于Ⅰ、Ⅱ期患者。本组患者染色体总变异数、扩增数和丢失数在不同的肿瘤部位、组织学类型和分化程度间比较．差异均无统计学意义。20q的扩增与TNM分期有关。结论染色体变异在SCRC中普遍存在,SCRC的染色体变异数及20q的扩增与TNM分期有关。     

广西地区乙肝病毒/黄曲霉毒素双暴露因素下肝细胞癌染色体遗传学改变的初步研究

目的 探讨广西地区人群乙肝病毒/黄曲霉毒素(HBV/AFB1)双暴露相关性肝细胞癌(HCC)染色体遗传学改变的特点.方法 32例HCC的癌组织,运用微阵列比较基因组杂交技术(Array CGH)检测其22对染色体的变化.结果 (1)32例HCC中,大部分的染色体拷贝数都有不同程度的变化.发生扩增的区段有1 q、7q、8q,其中1q、8q为高频扩增区段.发生缺失区段有1 p、4q、8p、9p、13q、14q、16p、16q、17p、18q、19p、Y,其中1p、4q、8p、16q、17p、19p为高频缺失区段;(2)同时,还存在着若干DNA拷贝数扩增或缺失的小区段.缺失显著的小区段有:2p25.1-p25.2、3q22.3-q23、7p14.1-p14.3.扩增显著的小区段有:9p13.2-9p21;(3)聚类分析发现:13q缺失发生率在HBsAg(+)/AFB1(+)、HBsAg(+)/AFB1(-)、HBsAg(-)/AFB1(+)、HBsAg(-)/AFB1(-)4个亚组中呈依次递减(x2=6.452,P＜0.05).4p在HBsAg(+)/AFB1(-)组中以扩增为主,而在HBsAg(-)/AFB1(+)组与HBsAg(-)/AFB1(-)组则以缺失为主.19q在HBsAg(+)/AFB1(+)组中以扩增为主,在HBsAg(-)/AFB1(+)组与HBsAg(-)/AFB1(-)组中以缺失为主.结论 广西地区肝癌染色体遗传学改变具有多样性,其中19p、2p25.1-25.2、3q22.3-q23的缺失及9p13.2-9p21的扩增可能为该地区肝癌特有的遗传学特征之一.13q的缺失可能与该地区乙肝病毒/黄曲霉毒素双因素的协同作用有关.     

前列腺癌及前列腺上皮内瘤13号染色体等位基因杂合性缺失分析

目的　探讨原发性前列腺癌及高级别前列腺上皮内肿瘤 (PIN) 13号染色体等位基因杂合性缺失 (LOH)及其意义。　方法　经显微切割技术获取前列腺癌及PIN标本各 10例。提取DNA ,采用PCR及微卫星多态性技术 ,对 13号染色体上 14个微卫星标志位点LOH进行检测。　结果　 10例原发性前列腺癌中 7例 13号染色体上至少有一个位点检测到LOH。 13q14及 13q12～ 13为两个高频LOH区。 10例PIN中 13号染色体的 14个位点均未检测到LOH。　结论　前列腺癌中存在 13号染色体的高频LOH区 ,乳腺癌易感基因 (BRCA2 )、视网膜母细胞瘤基因 (RB1)及位于附近的肿瘤抑制基因可能与前列腺癌的发生发展有关     

13号染色体重排所致严重少弱畸形精子症患者生精细胞减数分裂分析

目的:探讨13号染色体长臂相互缺失所致严重少弱畸形精子症患者生精阻滞的可能机制。方法:对1例13号染色体异常的严重少弱畸形精子症患者血液样本进行全基因组的寡核苷酸微阵列比较基因组杂交分析,以确定受累染色体的断裂点或基因缺失。对患者生殖细胞进行多色荧光原位杂交分析,以观察初级精母细胞13号染色体配对的情况。结果:寡核苷酸微阵列比较基因组杂交技术显示在13q12.3上有连续4个探针的缺失(A_16_P19757882,A_16_P02744617,A_14_P108858和A_16_P02744687),覆盖59.93 kb,位于基因FLT1和POMP之间,没有注释基因存在。初级精母细胞的减数分裂分析显示同源13号染色体配对错误,13q14和13qter信号彼此分离。结论:染色体重排导致的精子发生阻滞可能是由于生殖细胞第一次减数分裂同源染色体配对错误导致的。     

结肠直肠癌第17号染色体短臂等位基因丢失

作者早期的研究工作显示:Dukes分期,淋巴和/或毛细血管微浸润,肿瘤的大体形态和种族四个病理因素与结肠直肠癌根治术后五年生存率有关.同时作者还观察到ras原癌基因的过度表达与肿瘤的高度恶性行为和预后差有关.一般认为表现为等位基因缺失的肿瘤抑制基因失活(如杂合性等位基因丢失),至少部分地与恶性肿瘤的发展和其它生物学行为有关.结肠直肠癌中最频繁的杂合性等位基因缺失位点被定位在第5号染色体长臂(5q),第17号染色体短臂(17p)和第18号染色体长臂上(18q).这些可能是以下基因的位点,家族性结肠息肉病基因(APC)、p~(53)基因和结肠癌缺失基因(DCC).作者还研究了第8号染色体短臂(8p)的杂合性等位基因缺失,该处可能含有两个肿瘤抑制基因.为了阐明等位基因缺失作为潜在性预后因素的价值,现在报告:5q、8p、17p和18q上杂合性等位基因丢失与Dukes分期和微浸润之间的关系.     

散发性结直肠癌染色体20q11-13区杂合性缺失精细定位

目的 研究散发性结直肠癌20号染色体杂合性缺失情况,并对20q11-13区进行精细定位.方法 收集1998年至1999年上海市第一人民医院83例结直肠癌患者的肿瘤组织和对应的正常黏膜组织,采用10个微卫星标记的引物对20号染色体进行杂合性缺失分析,在20q11-13区域另取10个微卫星标记的引物并对标本进行PCR分析.以Genescan 3.1和Genotyper 2.1软件进行基因分型和精确定位.结果 在20号染色体上发现一个高频杂合性缺失区即20q11-13区.进一步的精细定位,界定了两个高频杂合性缺失区:20q11.2、20q12,并在该杂合性缺失区发现了抑癌基因E2F1、PMP24和MAFB.结论 20号染色体有两个高频精细杂合性缺失区,该区很可能存在一个或多个与结直肠癌相关的新的抑癌基因.     

肝癌转移机制的分子细胞遗传学研究

目的 探索肝癌转移的分子细胞遗传学机制。方法 应用比较基因组杂交技术（com-parative genomic hybridization,CGH)技术分析10对肝细胞癌原发癌及其转移癌灶的染色体变化。结果（1）肝癌中常见的染色体扩增包括1q(10/10)、8q(6/10)及5q(3/10),4例肝癌原发癌及6例转移灶中发现1q12-q22狭小区域的明显扩增。（2）常见的染色体缺失为4q(7/10)、1q(6/10)（且多局限于lpter-p35)、17q(5/10)、19q(4/10)、16q(4/10)及8p(3/10)。（3）转移癌灶中各染色体异常的比例略高于原发癌,但最有意义的发现是8例转移癌灶（8/10,80%）中存在8p的缺失,而原发癌中仅3例（3/10.30%）存在8p缺失（P=0.03),5例肝细胞癌在其获得转移表型时存在8p的缺失。（4）加一重要发现是在所有10对肝癌的原发癌及其转移癌灶中均存在1q的扩增,并在部分癌灶中发现小区域的明显扩增。结论 染色体8q的缺失可能与肝癌的转移特性有关,8q可能存在抑制肝癌转移的基因,1q12-q22可能存在与肝癌发生发展有关的癌基因。     

Loss of heterozygosity at 7q31.1 and 12p13-12 in advanced prostate cancer

BACKGROUND: Allelic losses on chromosome arms 2q, 3p, 5q, 6q, 7q, 8p, 9p, 10p, 10q, 11p, 11q, 12p, 13q, 16q, 17p, 17q, 18q, and 21q are reportedly associated with progression and/or initiation of prostate cancer. In the present study, we performed a polymerase chain reaction (PCR) analysis of polymorphic microsatellite loci on the human chromosomes 7 and 12p13-12 in prostate cancer tissue to investigate the extent of involvement of these regions, which may contain putative tumor suppressor genes. METHODS: Tissue samples were obtained at autopsy from 17 men who died of hormone-refractory prostate cancer at Chiba University, Japan, and affiliated hospitals between June of 1992 and June of 1995. DNA from normal tumor or metastatic tissue was used as the template for PCR amplification of a set of 16 polymorphic microsatellite loci on human chromosome 7 and 6 loci on the human chromosome region 12p13-12. RESULTS: The frequencies of cases with loss of heterozygosity (LOH) at 7q31.1 were 8% in primary tumor tissue and 11% in metastatic tissue. The frequencies of cases with LOH at 12p13-12 were 12% in primary tumor tissue and 25% in metastatic tumor tissue. CONCLUSIONS: In the present study, the frequencies of LOH at 7q31.1 were lower than in Western patients, suggesting that LOH in this region is not related to progression of prostate cancer in Japanese patients. The frequency of LOH at 12p13-12 was similar to that reported in Western countries, indicating that 12p13-12 may contain a tumor suppressor gene of prostate cancer.     

Genetic aberrations in prostate carcinoma detected by comparative genomic hybridization and microsatellite analysis: association with progression and angiogenesis

BACKGROUND: In spite of increasing knowledge about the tumor biology of prostate cancer (PC), molecular events involved in tumor progression are not well characterized. There is evidence that a number of genetic alterations play a role in tumor progression and in addition, angiogenesis also contributes. In this study, comparative genomic hybridization (CGH), a sensitive method for detecting regional DNA copy number abnormalities, and microsatellite analysis was used to identify frequent genome changes in PC. Correlation of these data with microvessel density (MVD) and clinical follow-up data was performed to determine genetic alterations that are associated with angiogenesis and subsequent tumor progression. METHODS: Fifty-seven paraffin embedded radical prostatectomy (RP) specimens were microdissected. DNA from the microdissected PC tissue was amplified by degenerate oligonucleoitide primed (DOP)-polymerase chain reaction (PCR), and CGH was performed on the PCR product. Quantitative analyses of the CGH profiles were performed using a t-statistic. Additionally, a microsatellite analysis of chromosome 13q was performed on a subgroup of 31 of the tumors. Using a polyclonal antibody against factor VIII, MVD was determined for all RP specimens. The results of CGH and microsatellite analysis were correlated with the clinical data of the patients and with MVD. RESULTS: Forty-two of the tumors (75%) showed one or more gains while 39 (70%) showed one or more losses per tumor. The most frequent DNA copy number gains were on chromosome 3, 4, 7, 8, 10, 11, 12, 13, and X. The most frequent losses were on chromosomes 2, 5, 6, 8, 10, 13, 15, and 16. Cancer recurrence occurred in 15 patients. The total number of DNA copy number losses was significantly higher in patients with this progression (86%) than without (52%) (P < 0.001). There was no significant difference in the number of gains in patients with or without progression. Contingency table analysis showed a significant correlation between progression and losses in regions of chromosomes 6q and 13q and a gain of chromosome 7q. In multivariate analysis, only loss of chromosome 6 was independently prognostic. The gains that correlated most closely with MVD > 35 were on chromosomes 2q, 7q, and Xq, while the losses most closely associated with MVD > 35 were on chromosomes 8q, 10q, and 13q. However, only the association between loss of chromosome 13q and MVD > 35 was statistically significant. Microsatellite analysis revealed a statistically significant correlation between MVD and instability of locus 171. CONCLUSIONS: This study indicates that the frequency of genetic alterations in PC as detected by CGH correlates with clinical outcome, and that losses of DNA from chromosomes 6q and 13q are important events that correlate with tumor progression, with loss of 13q, especially instability of locus 171, also associated with angiogenesis.     

Review of allelic loss and gain in prostate cancer

Summary There are three nearly ubiquitous genomic imbalances in prostate cancer cells: 1) loss of sequences from the short arm of chromosomes 8, 2) loss of sequences from the long arm of chromosome 13q, and 3) gain of sequences on the long arm of chromosome 8, particularly in advanced disease. Candidate tumor suppressor genes and oncogenes affected by this trio of consistent changes include the c-myc gene on chromosome 8q24, the RB gene at 13q14, and potentially multiple novel genes on the short arm of chromosome 8, with a gene located more proximally potentially involved in tumor initiation and a gene or genes located more distally involved in tumor progression. Loss of regions of chromosomes 2q, 5q, 6q, 7p and 7q, 9p, 10p and 10q, 16q, 17p and 17q, and 18q, and gain of regions of 1q, 2p, 3p and 3q, 7p and 7q, 11p, 17q, and Xq have also been detected in the range of 25–50% of tumors studied. Analysis of candidate tumor suppressor genes in these regions is still in its early stages. Similarly, potential oncogenes on a series of chromosomal arms which undergo frequent amplification remain essentially uncharacterized. The basic outline of the chromosomal aberrations in prostate cancer has been well established; the details of the story remain to be filled in. This paper reviews the advantages and disadvantages of various techniques for detection of genomic loss and gain in prostate cancer cells, and reviews published reports of loss and gain in prostate cancer, focusing primarily on reports using microsatellite analysis, Southern analysis, and comparative genomic hybridization. Fluorescence in situ hybridization (FISH) based analyses of selected regions are also reviewed.     

Comparative genomic hybridization reveals DNA copy number gains to frequently occur in human prostate cancer

BACKGROUND: Despite intensive studies over many years, there is only limited knowledge on the genetic changes underlying the development and progression of prostate cancer. No specific prostate carcinoma-related genetic event has yet been identified. METHODS: In order to gain an overall view of regional chromosome gains and losses, comparative genomic hybridization (CGH) was used on a series of 16 prostate adenocarcinomas. Five benign prostate hyperplasia (BPH) samples were also evaluated. RESULTS: Using CGH, chromosome alterations were observed in 81% of the prostate carcinomas analyzed. Gains of DNA copy numbers were found as the predominant imbalance, with chromosomes 3q (56%), 12q (56%), 8q (50%), Xq (50%), 4 (44%), 6q (44%), 5 (38%), 7q (38%), 9p (38%), and 13q (31%) being most frequently involved. Whereas DNA copy number gains comprised the whole chromosome or almost a whole arm of chromosomes 4, 5, 6, 9, and 13, the minimal overlapping regions on the other chromosomes were mapped to 3q25-q26, 8q21-q22, 12q13-q21, 7q31, and Xq22-q25. High-level amplifications were not found. Other chromosomes with nonrandom gains or losses of DNA sequences were discovered. The five BPH samples were found to be normal. CONCLUSIONS: Amplification events at different chromosomal sites seem important in prostate cancer development. A new chromosome region with DNA copy number gains was identified on 12q, while other regions on 3q, 7q, 8q, and Xq were confirmed or narrowed down, indicating a possible role of known or putative protooncogenes in these regions for prostate cancer growth. Our low detection rate of DNA losses may to some part be explained by CGH immanent technical limitations.     

Genome-wide screening for genetic changes in a matched pair of benign and prostate cancer cell lines using array CGH

Copy number alterations in a matched pair of benign epithelial and prostate cancer cell lines derived from the same patient were assessed using array-based comparative genomic hybridisation (aCGH). The cancer cell line showed a gain of chromosome 7, deletion of chromosome 8, gains (including high level) and losses on chromosome 11, loss of 18p and gain of 20q. Deletions on chromosome 8 were confirmed with microsatellite markers. The aCGH results were compared to gene expression data obtained using DNA microarrays and suggested the involvement of caspases and ICEBERG on 11q and E2F1 on chromosome 20q.     

Chromosome arm 1q gain associated with good response to chemotherapy in a malignant glioma. Case report

The authors describe the case of a patient with a glioblastoma multiforme who showed remarkably good response to chemotherapy. A genetic analysis using comparative genomic hybridization (CGH) revealed that the tumor had a gain on the q arm of chromosome 1 (1q). Using CGH for a series of genetic analyses of more than 180 patients with gliomas, six were found to have a demonstrated 1q gain. Although the tumors in all six of these cases were histopathologically diagnosed as high-grade gliomas, compared with other malignant gliomas they demonstrated a good prognosis because of their favorable chemotherapeutic sensitivity. In immunohistochemical tests, most of the tumor cells in these cases were negative for O6-methylguanine-DNA methyltransferase, which antagonizes the effect of DNA-alkylating chemotherapeutic agents. The authors believed that a gain of 1q could be produced through the genetic events that cause loss of 1p, because these chromosomal aberrations have an imbalance of DNA copy number in common (1p < 1q). A gain of 1q is an infrequent chromosomal aberration and its clinical importance should be investigated in a larger study; however, patients with malignant gliomas demonstrating a 1q gain possibly show longer survival and good response to chemotherapy similar to patients with tumors demonstrating 1p loss. The importance of using genetic analysis for gliomas is emphasized in this report because it may help in selecting cases responsive to chemotherapy and because appropriate treatment for these patients will lead to progress in the treatment of malignant gliomas.     

Chromosomal changes in incidental prostatic carcinomas detected by comparative genomic hybridization

OBJECTIVES: The genetic changes underlying the development and progression of prostate cancer are poorly understood. To identify chromosomal regions in incidental prostatic carcinoma (T1a and T1b) was the primary aim of this study. MATERIALS AND METHODS: We used comparative genomic hybridization (CGH) to search for DNA sequence copy number changes on a series of 48 T1 prostate cancer diagnosed by transurethral resection (TURP) and by adenomectomy. Incidental prostatic carcinomas have not been studied by CGH previously. RESULTS: CGH analysis indicated that 14 cases (29.2%) of incidental prostatic carcinoma showed chromosome alterations. The most frequent alterations were chromosomal losses of 8p (10.4%), 13q (6.3%), 5q (4.2%) and 18q (4.2%), and gains of 17p (10.4%), 17q (10.4%), 9q (6.3%) and 7q (4.2%). Minimal overlapping chromosomal regions of loss, indicative for the presence of tumor suppressor genes (TSGs), were mapped to 8p22 and 13q14.1-q21.3, and minimal overlapping regions of gain, indicative for the presence of oncogenes, were found at 9q34.2-qter, 17p12 and 17q24-qter. The statistical analysis displayed a significant association between chromosomal aberration detected by CGH and high Gleason score (P < 0.005) as well as between tumor categories T1a and T1b and chromosomal imbalance (P = 0.041). CONCLUSIONS: Studies directed at incidental prostatic carcinomas allow discovery of chromosomal changes in small and highly malignant tumors. Our results suggest that loss or gain of DNA in these regions are important in prostate cancer. This is the first study, which documents the spectrum of chromosomal changes in incidental prostatic carcinomas.     

Genetic and chromosomal alterations in prostatic intraepithelial neoplasia and carcinoma detected by fluorescence in situ hybridization.

OBJECTIVE: In this review, we discuss the utility of fluorescence in situ hybridization (FISH) in the determination of genetic and chromosomal alterations in prostate cancer specimens. We also discuss the genetic association between prostatic intraepithelial neoplasia (PIN) and adenocarcinoma as detected by FISH and other techniques. METHODS AND RESULTS: FISH is a commonly used technique for the determination of gene and chromosome dosage. In tissue sections, FISH allows precise histopathologic correlation of multiple foci of normal epithelium, premalignant lesions, and carcinoma within a single specimen, including study of intratumoral heterogeneity. PIN and prostatic carcinoma foci have a similar proportion of genetic changes, but foci of carcinoma usually have more alterations. This supports the hypothesis that PIN is the most likely precursor of prostatic carcinoma. The most common genetic alterations in PIN and carcinoma are: (1) gain of chromosome 7, particularly 7q31; (2) loss of 8p and gain of 8q, and (3) loss of 10q, 16q and 18q. Inactivation of tumor suppressor genes and/or overexpression of oncogenes in these regions may be important for the initiation and progression of prostate cancer. CONCLUSIONS: FISH is a useful technique to determine genetic relationships between cancer and its precursors. PIN and prostatic carcinoma foci have a similar proportion of genetic alterations, suggesting that PIN is often a precursor of prostatic carcinoma. Genes on chromosomes 7, 8, 10, 16 and 18 may play an important role in both initiation and progression of prostatic carcinoma.