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1.
The aim of the present study was to investigate the chromosomal aberrations that are linked with the crucial clinicopathological features of colorectal cancer (CRC) and its prognosis by array-based comparative genomic hybridization (CGH). Fresh-frozen tumor tissues of 94 cases of CRC were analyzed by using bacterial artificial chromosome (BAC) CGH slides spotted with 4030 human BAC clones, which covered the whole range of the human genome at an average interval of 0.83 mega base pairs. DNA copy number aberrations (DCNAs) were identified in association with clinicopathological features: a gain of 8q24.3 and losses of 9q33.1 and 20p12.2 were associated with lymph node metastasis, gain of 8q24.3 and loss of 9q33.1 with disease stage, gain of 8q21.11 and loss of 10q21.3 with lymphovascular invasion and losses of 3p25.1, 10p15.3, 12q15 and 17p13.1 for venous invasion. These aberrations can be regarded as genomic biomarkers to predict the clinical outcome of patients with CRC, and are expected to serve to individualize the treatment of CRC patients.  相似文献   

2.
DNA copy number changes were analyzed by comparative genomic hybridization (CGH) in 53 esophageal squamous cell carcinomas (ESCC) to clarify the relationship between DNA sequence copy number aberrations and clinicopathological factors. Changes in DNA copy number were observed in all 53 ESCC patients. The average number of DNA copy number gains was 9.32 (range 1-23), most frequently located on chromosomes 3q, 5p, 8q, 11q and Xq in over 40% of tumors. Loss of DNA copy number was detected on 3p, 5q, 4p, 1p and Xp in over 20% of tumors. No statistically significant differences in the frequency of DNA copy number changes were observed. However, some loci showed correlation with clinicopathologic factors: 8q gain correlated with the pattern of tumor infiltration, 3q gain correlated with pT, 2p gain, 1p loss and 16p loss correlated with lymphatic invasion, and 3q gain correlated with clinical stage. Thus, in ESCC, gain of 3q is the only specific recurrent pattern of DNA aberration that correlates with clinicopathologic parameters, although no particular loci correlated with patient prognosis. Further CGH analysis may reveal new, recurrent genetic changes in ESCC affecting chromosomes sites that harbor genes known to participate in tumorigenesis and progression of several human malignant neoplasms.  相似文献   

3.
4.
The goals of this study were to evaluate the potential of detecting cryptic amplification and deletion of cancer-related genes using array-based comparative genomic hybridization (CGH), and to identify candidate cancer genes by combined parallel analyses of copy number and gene expression profiles in nasopharyngeal carcinoma (NPC) cell lines. We established global DNA copy number and mRNA expression profiles on human NPC cell lines using a high-density cDNA microarray. The DNA copy number alterations detected by array CGH were compared to the DNA copy number variations identified by metaphase CGH. A cryptic amplification at 3q26 was detected by array CGH, which was not found by metaphase CGH. By amplicon mapping and parallel analyses of DNA copy number and mRNA expression levels, we identified several candidates which could be important mediators in tumor formation or progression. Taken together, the combination of copy number and gene expression profiling using cDNA microarrays provides an improved strategy for gene discovery in human cancer.  相似文献   

5.
Array-based comparative genomic hybridization (CGH) allows for the simultaneous examination of thousands of genomic loci at 1-2 Mb resolution. Copy number alterations detected by array-based CGH can aid in the identification and localization of cancer causing genes. Here we report the results of array-based CGH in a set of 125 primary colorectal tumors hybridized onto an array consisting of 2463 bacterial artificial chromosome clones. On average, 17.3% of the entire genome was altered in our samples (8.5 +/- 6.7% gained and 8.8 +/- 7.3% lost). Losses involving 8p, 17p, 18p or 18q occurred in 37, 46, 49 and 60% of cases, respectively. Gains involving 8q or 20q were observed 42 and 65% of the time, respectively. A transition from loss to gain occurred on chromosome 8 between 41 and 48 Mb, with 25% of cases demonstrating a gain of 8p11 (45-53 Mb). Chromosome 8 also contained four distinct loci demonstrating high-level amplifications, centering at 44.9, 60, 92.7 and 144.7 Mb. On 20q multiple high-level amplifications were observed, centering at 32.3, 37.8, 45.4, 54.7, 59.4 and 65 Mb. Few differences in DNA copy number alterations were associated with tumor stage, location, age and sex of the patient. Microsatellite stable and unstable (MSI-H) tumors differed significantly with respect to the frequency of alterations (20 versus 5%, respectively, P < 0.01). Interestingly, MSI-H tumors were also observed to have DNA copy number alterations, most commonly involving 8q. This high-resolution analysis of DNA copy number alterations in colorectal cancer by array-based CGH allowed for the identification of many small, previously uncharacterized, genomic regions, such as on chromosomes 8 and 20. Array-based CGH was also able to identify DNA copy number changes in MSI-H tumors.  相似文献   

6.
目的探讨肝细胞癌染色体异常及其临床意义。方法运用比较基因组杂交技术检测25例肝细胞癌染色体DNA异常情况,并与临床指标作相关分析。结果25例肝癌均存在不同程度的染色体DNA拷贝数的扩增或缺失,较为常见的染色体DNA异常是+1q(72%)、+1p(64%)、+2q(、48%)、+2p(48%)、+5q(48%)、+Xq(48%)、+7q(44%)、-4q(48%)、-16p(48%)、-8p(40%)、-17p(36%);相关分析显示+17p、+18p、-8p、-13q、-11q、-8q染色体异常事件与临床指标部分相关。结论肝细胞癌存在明显的染色体异常,部分染色体异常事件是非随机性的,可能与肝癌的发生、发展有关,并与肿瘤的生物学行为和预后相关。  相似文献   

7.
Alterations in genomic content and changes in gene expression levels are central characteristics of tumors and pivotal to the tumorigenic process. We analyzed 23 non-small cell lung cancer (NSCLC) tumors by array comparative genomic hybridization (array CGH). Aberrant regions identified included well-characterized chromosomal aberrations such as amplifications of 3q and 8q and deletions of 3p21.31. Less frequently identified aberrations such as amplifications of 7q22.3-31.31 and 12p11.23-13.2, and previously unidentified aberrations such as deletion of 11q12.3-13.3 were also detected. To enhance our ability to identify key acting genes residing in these regions, we combined array CGH results with gene expression profiling performed on the same tumor samples. We identified a set of genes with concordant changes in DNA copy number and expression levels, i.e. overexpressed genes located in amplified regions and underexpressed genes located in deleted regions. This set included members of the Wnt/beta-catenin pathway, genes involved in DNA replication, and matrix metalloproteases (MMPs). Functional enrichment analysis of the genes both overexpressed and amplified revealed a significant enrichment for DNA replication and repair, and extracellular matrix component gene ontology annotations. We verified the changes in expressions of MCM2, MCM6, RUVBL1, MMP1, MMP12 by real-time quantitative PCR. Our results provide a high resolution map of copy number changes in non-small cell lung cancer. The joint analysis of array CGH and gene expression analysis highlights genes with concordant changes in expression and copy number that may be critical to lung cancer development and progression.  相似文献   

8.
Genome-wide copy number profiles were characterized in 41 primary bladder tumors using array-based comparative genomic hybridization (array CGH). In addition to previously identified alterations in large chromosomal regions, alterations were identified in many small genomic regions, some with high-level amplifications or homozygous deletions. High-level amplifications were detected for 192 genomic clones, most frequently at 6p22.3 (E2F3), 8p12 (FGFR1), 8q22.2 (CMYC), 11q13 (CCND1, EMS1, INT2), and 19q13.1 (CCNE). Homozygous deletions were detected in 51 genomic clones, with four showing deletions in more than one case: two clones mapping to 9p21.3 (CDKN2A/p16, in nine cases), one at 8p23.1 (three cases), and one at 11p13 (two cases). Significant correlations were observed between copy number gain of clones containing CCNE1 and gain of ERBB2, and between gain of CCND1 and deletion of TP53. In addition, there was a significant complementary association between gain of CCND1 and gain of E2F3. Although there was no significant relationship between copy number changes and tumor stage or grade, the linked behavior among genomic loci suggests that array CGH will be increasingly important in understanding pathways critical to bladder tumor biology.  相似文献   

9.
The aim of this study was to screen genetic as well as expression alterations in prostate cancer. Array comparative genomic hybridization (aCGH) to a 16K cDNA microarray was performed to analyze DNA sequence copy number alterations in 5 prostate cancer cell lines and 13 xenografts. The aCGH confirmed the previously implicated common gains and losses, such as gains at 1q, 7, 8q, 16p and 17q and losses at 2q, 4p/q, 6q, 8p, 13q, 16q, 17p and 18q, which have previously been identified by chromosomal CGH (cCGH). Because of the higher resolution of aCGH, the minimal commonly altered regions were significantly narrowed-down. For example, the gain of 8q was mapped to three independent regions, 8q13.3-q21.11, 8q22.2 and 8q24.13-q24.3. In addition, a novel recurrent gain at 9p13-q21 was identified. The concomitant expression analysis indicated that genome-wide DNA sequence copy number (gene dosage) was significantly associated with the expression level (p < 0.0001). The analyses indicated several individual genes whose expression was associated with the gene copy number. For example, gains of PTK2 and FZD6, were associated with the increased expression, whereas losses of TNFRSF10B (alias DR5) and ITGA4 with decreased expression. In conclusion, the aCGH mapping data will aid in the identification of genes altered in prostate cancer. The combined expression and copy number analysis suggested that even a low-level copy number change may have significant effect on gene expression, and thus on the development of prostate cancer.  相似文献   

10.
BACKGROUND: The genetic aberrations associated with development and progression of gastric carcinomas (GCs) are poorly understood. The aim of this study was to identify chromosomal aberrations associated with the development and/or progression of intestinal-type GC. MATERIALS AND METHODS: Comparative genomic hybridization (CGH) analysis was applied to 36 intestinal-type GCs. We compared chromosomal aberrations detected by CGH analysis with clinicopathological parameters. RESULTS: Frequent gains of DNA copy number were found on 8q, 13q, 20q, 3q, 6q and losses were found on 17p, 18q in intestinal-type GCs. No significant differences were observed in the chromosomal aberrations between tumor stage, tumor location, peritoneal dissemination, liver metastasis or other distant metastasis. However, the frequencies of 20q12-13 gain and 18q21-22 loss were significantly higher in tumors with lymph node metastasis than in those without metastasis. CONCLUSION: Gains of 20q and losses of 18q may contribute to lymph node metastasis and the malignant phenotype in intestinal-type GCs.  相似文献   

11.
Comparative genomic hybridization (CGH) is used to detect amplified and/or deleted chromosomal regions in tumours by mapping their locations on normal metaphase chromosomes. Forty-five sporadic colorectal carcinomas were screened for chromosomal aberrations using direct CGH. The median number of chromosomal aberrations per tumour was 7.0 (range 0-19). Gains of 20q (67%) and losses of 18q (49%) were the most frequent aberrations. Other recurrent gains of 5p, 6p, 7, 8q, 13q, 17q, 19, X and losses of 1p, 3p, 4, 5q. 6q, 8p, 9p, 10, 15q, 17p were found in > 10% of colorectal tumours. High-level gains (ratio > 1.5) were seen only on 8q, 13q, 20 and X, and only in DNA aneuploid tumours. DNA aneuploid tumours had significantly more chromosomal aberrations (median number per tumour of 9.0) compared to diploid tumours (median of 1.0) (P < 0.0001). The median numbers of aberrations seen in DNA hyperdiploid and highly aneuploid tumours were not significantly different (8.5 and 11.0 respectively; P = 0.58). Four tumours had no detectable chromosomal aberrations and these were DNA diploid. A higher percentage of tumours from male patients showed Xq gain and 18q loss compared to tumours from female patients (P = 0.05 and 0.01 respectively). High tumour S phase fractions were associated with gain of 20q13 (P = 0.03), and low tumour apoptotic indices were associated with loss of 4q (P = 0.05). Tumours with TP53 mutations had more aberrations (median of 9.0 per tumour) compared to those without (median of 2.0) (P = 0.002), and gain of 8q23-24 and loss of 18qcen-21 were significantly associated with TP53 mutations (P = 0.04 and 0.02 respectively). Dukes' C/D stage tumours tended to have a higher number of aberrations per tumour (median of 10.0) compared to Dukes' B tumours (median of 3.0) (P = 0.06). The low number of aberrations observed in DNA diploid tumours compared to aneuploid tumours suggests that genomic instability and possible growth advantages in diploid tumours do not result from acquisition of gross chromosomal aberrations but rather from selection for other types of mutations. Our study is consistent with the idea that these two groups of tumours evolve along separate genetic pathways and that gross genomic instability is associated with TP53 gene aberrations.  相似文献   

12.
Breast cancer is characterised by a number of genetic aberrations. Our purpose was to use comparative genomic hybridisation (CGH) to screen breast carcinomas for copy number changes: 44 ductal and 8 lobular carcinomas were studied and a large number of genetic aberrations identified. Many of these showed similarity to previous CGH results, however, a number of loci not previously shown to have undergone frequent change were identified. This included copy number gains affecting chromosomes 1p, 4q, 5q, 6q and 13q. Furthermore, we have identified 2 regions of copy number change, the gain on 5p and deletion of 16q, which correlated with lobular carcinomas. Our results highlight several areas of the genome that may be important in the molecular genetics of breast cancer.  相似文献   

13.
To identify the chromosomal aberrations associated with the progression of liver cancer, we applied expression imbalance map analysis to gene expression data from 31 hepatocellular carcinomas and 19 noncancerous tissues. Expression imbalance map analysis, which detects mRNA expression imbalance correlated with chromosomal regions, showed that expression gains of 1q21-23 (74%), 8q13-21 (48%), 12q23-24 (41%), 17q12-21(48%), 17q25 (25%), and 20q11 (22%) and losses of 4q13 (48%), 8p12-21 (32%), 13q14 (32%), and 17p13 (29%) were significantly associated with hepatocellular carcinoma. Most regions with altered expression identified by expression imbalance map were also identified in previous reports using comparative genomic hybridization. We demonstrated chromosomal copy number gain in 1q21-23 and loss in 17p13 by genomic quantitative PCR, suggesting that gene expression profiles reflect chromosomal alterations. Furthermore, expression imbalance map analysis revealed that more poorly differentiated hepatocellular carcinoma contain more chromosomal alterations, which are accumulated in a stepwise manner in the course of hepatocellular carcinoma progression: expression imbalance of 1q, 8p, 8q, and 17p occur as early events in hepatocarcinogenesis, and 12q, 17q25 and 20q occur as later events. In particular, expression gain of 17q12-21 and loss of 4q were seen to accumulate constantly through the dedifferentiation process. Our data suggest that gene expression profiles are subject to chromosomal bias and that expression imbalance map can correlate gene expression to gene loci with high resolution and sensitivity.  相似文献   

14.
BACKGROUND: Biologic characteristics of tumors are greatly affected by genetic aberrations. However, to the authors' knowledge there is no study that shows that cytogenetic information is useful for estimating prognosis of patients with hepatocellular carcinoma (HCC). METHODS: Comparative genomic hybridization (CGH) analysis was performed in 41 HCCs to examine whether the analysis of cytogenetic aberrations allows us to estimate biologic behavior of HCC. RESULTS: Tumor recurrence was linked to the loss at 13q (P = 0.0027) and to the number of DNA copy number aberrations (DCNAs; P = 0.0003). The decrease in DNA copy number at 8p and 13q and amplification at 11q13 were significantly associated with unfavorable outcome of patients (P = 0.017, P = 0.012, and P = 0.00081, respectively). The number of DCNAs was significantly different between favorable and poor prognosis patients with HCC; 5.78 +/- 2.7 versus 11.13 +/- 4.8 (P = 0.004), and it was an independent prognostic marker in HCCs. CONCLUSIONS: The current study indicates that cytogenetic information provided by CGH is useful for estimating prognosis of patients with HCC.  相似文献   

15.
Oral squamous cell carcinoma (OSCC) is a common malignancy worldwide and the prognosis for patients with advanced-stage OSCC is particularly poor. To identify DNA copy number aberrations and candidate genes associated with a poor or favorable outcome, we analyzed the genome profiles of OSCC tumors by array-based comparative genomic hybrid-ization (A-CGH). This technique uses DNA microarray technology to detect genomic copy number variations at a higher resolution level than chromosome-based CGH. Fifty patients with primary OSCCs were included in the study. Of these 50 patients, 37 were treated surgically and 13 were treated without surgery and had received irradiation and/or chemotherapy. All samples were analyzed by A-CGH. Gains were detected frequently (>50%) at chromosomal regions 5p15.33, 7p22.3, 8q21.1-24.3, 9q34.3, 11q13, 16p13.3 and 20q13.3. Losses were frequently detected at 3p22, 3p14 and 4q35.2. High-level gains were recurrently (>10%) detected at each of 5p15, 7p22, 7p11, 8q24, 11q13, 11q22 and 22q11. Gains of 2p25.1, 11p15, 16p13.3, 16q24.3 and 20q13.3 were inversely correlated with nodal metastasis. In 37 of the 50 OSCC patients treated with surgery, gains of 8q12.1-24.22 and losses of 3p26.2-3 were associated with disease-specific survival (p<0.01). Loss of a 0.2 Mb chromosomal region in 3p26.3 was associated with a poor prognostic outcome in the Kaplan-Meier analysis (p<0.01 by the log-rank test). Multivariate analysis revealed that loss of 3p26.3 is an independent prognostic factor (p<0.01) of OSCC. Loss of a 0.2 Mb chromosomal region in 3p26.3 including the CHL1 (cell adhesion molecule with homology to L1CAM1) gene was identified as a novel potential marker for predicting the prognosis of patients with OSCC.  相似文献   

16.
Classical comparative genomic hybridization (CGH) has been used to identify recurrent genomic alterations in human HCC. As hepatocarcinogenesis is considered as a stepwise process, we applied oncogenetic tree modeling on all available classical CGH data to determine occurrence of genetic alterations over time. Nine losses (1p, 4q, 6q, 8p, 9p, 13q, 16p, 16q and 17p) and ten gains (1q, 5p, 6p, 7p, 7q, 8q, 17q, 20p, 20q and Xq) of genomic information were used to build the oncogenetic tree model. Whereas gains of 1q and 8q together with losses of 8p formed a cluster that represents early etiology-independent alterations, the associations of gains at 6q and 17q as well as losses of 6p and 9p were observed during tumor progression. HBV-induced HCCs had significantly more chromosomal aberrations compared to HBV-negative tumors. Losses of 1p, 4q and 13q were associated with HBV-induced HCCs, whereas virus-negative HCCs showed an association of gains at 5p, 7, 20q and Xq. Using five aberrations that were significantly associated with tumor dedifferentiation a robust progression model of stepwise human hepatocarcinogensis (gain 1q → gain 8q → loss 4q → loss 16q → loss 13q) was developed. In silico analysis revealed that protumorigenic candidate genes have been identified for each recurrently altered hotspot. Thus, oncogenic candidate genes that are coded on chromosome arms 1q and 8q are promising targets for the prevention of malignant transformation and the development of biomarkers for the early diagnosis of human HCC that may significantly improve the treatment options and thus prognosis of HCC patients.  相似文献   

17.
Chromosomal copy number changes were investigated in 16 prostate carcinomas, 12 prostatic intraepithelial neoplasias (PIN; 4 low-grade and 8 high-grade) adjacent to the invasive tumour areas, and 5 regional lymph node metastases. For this purpose, comparative genomic hybridization (CGH) was performed and a copy number karyotype for each histomorphological entity was created. CGH on microdissected cells from non-neoplastic glands was carried out on 3 different cases to demonstrate the reliability of the overall procedure. None of the non-neoplastic tissue samples revealed chromosome copy number changes. In PIN areas, chromosomal imbalances were detected on chromosomes 7, 8q, Xq (gains), and on 4q, 5q, 8p, 13q and 18q (losses). In the primary tumours, recurrent (at least 25% of cases) gains on chromosomes 12q and 15q, and losses on 2q, 4q, 5q, Xq, 13q and 18q became apparent. Losses on 8p and 6q as well as gains on 8q and of chromosome 7 were also detected at lower frequencies than previously reported. The pooled CGH data from the primary carcinomas revealed a novel region of chromosomal loss on 4q which is also frequently affected in other tumour entities like oesophageal adenocarcinomas and is supposed to harbour a new tumour suppressor gene. Gains on chromosome 9q and of chromosome 16 and loss on chromosome 13q were observed as common aberrations in metastases and primary tumours. These CGH results indicate an accumulation of chromosomal imbalances during the PIN-carcinoma-metastasis sequence and an early origin of tumour-specific aberrations in PIN areas.  相似文献   

18.
We analyzed 10 adenoid cystic carcinomas (ACCs) of the salivary glands by array-based comparative genomic hybridization (a-CGH) using DNA chips spotted with 4,030 bacterial artificial chromosome clones. After the data smoothing procedure was applied, a total of 88 DNA copy number aberrations (DCNAs) were detected. The frequent (≥30%) DCNAs were loss of 6q23-27 and 8p23, and gains of 6p, 6q23, 8p23 and 22q13. High-level gains were detected on 12q15, including MDM2 in two cases. These two cases showed an immunohistochemically high-level (>50%) expression of MDM2 and a low-level expression of p53 (<20%). Furthermore, the total number of DCNAs was significantly greater in ACCs with loss of 6q compared to other ACCs, and in ACCs without the loss of 8p23 compared to other ACCs, respectively. Although limitations exist, a-CGH detected several candidate chromosomal imbalances associated with accumulation of DCNAs in ACCs.  相似文献   

19.
Genomic amplification of oncogenes and inactivation of suppressor genes are critical in the pathogenesis of human cancer. To identify chromosomal alterations associated with hepatocarcinogenesis, we performed allelic gene dosage analysis on 36 hepatocellular carcinomas (HCCs). Data from high-density single-nucleotide polymorphism arrays were analysed using the Genome Imbalance Map (GIM) algorithm, which simultaneously detects DNA copy number alterations and loss of heterozygosity (LOH) events. Genome Imbalance Map analysis identified allelic imbalance regions, including uniparental disomy, and predicted the coexistence of a heterozygous population of cancer cells. We observed that gains of 1q, 5p, 5q, 6p, 7q, 8q, 17q and 20q, and LOH of 1p, 4q, 6q, 8p, 10q, 13q, 16p, 16q and 17p were significantly associated with HCC. On 6q24-25, which contains imprinting gene clusters, we observed reduced levels of PLAGL1 expression owing to loss of the unmethylated allele. Finally, we integrated the copy number data with gene expression intensity, and found that genome dosage is correlated with alteration in gene expression. These observations indicated that high-resolution GIM analysis can accurately determine the localizations of genomic regions with allelic imbalance, and when integrated with epigenetic information, a mechanistic basis for inactivation of a tumor suppressor gene in HCC was elucidated.  相似文献   

20.
Genomic alterations have been identified in lung cancer tissues and reported in numerous studies. To analyze genomic aberrations in lung cancer patients, we used array comparative genomic hybridization (array CGH) in 14 squamous cell lung carcinoma (SqC) tissues. Copy number gain and loss in chromosomal regions were detected, and the corresponding genes were confirmed by real time PCR. Several frequently altered loci, including gain of 3q (36% of samples), were found. The most frequently identified losses were found at 14q32.33 (21% of samples). The relative degree of chromosomal change was analyzed using log2 ratios. High-level DNA amplifications (>0.8 log2 ratio) were detected at 20 regions in 1p, 2q, 3q, 4q, 6q, 7p, 8q, 9p, 10q, 12q, 14q and 19p. We found that the fold change levels were highest at EVI1 (3q26.2), LPP (3q27-28) and FHF-1 (3q28) gene loci. Our results show that array CGH is a useful tool for identification of gene alteration in lung cancer, and that the above-mentioned genes might represent potential candidate genes for pathogenesis and diagnosis of lung cancer.  相似文献   

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