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.     

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。     

Simultaneous heterogenotypic renal cell carcinoma: immunohistochemical and karyoptic analysis by comparative genomic hybridization

We report a rare collision tumor of a nodule-in-nodule pattern between a clear cell-type carcinoma and a collecting duct carcinoma in a 24-year-old man. Whereas the outer nodule is quite different from the 'conventional renal cell carcinoma (RCC)' with respect to vascularity, the inner nodule is quite distinctive as regards immunophenotype and karyotype results. Karyotyping the latter by means of comparative genomic hybridization (CGH) disclosed gains of chromosome regions in 1q21.2-qter, 5q21-qter, 6q16.3-qter and 17q21.2-qter along with a loss in 1p21-p31.14, 9q31-pter, 11, 13q12-qter, 15q12-qter and 18q21.1-qter. The clear cell carcinoma surrounding the daughter nodule revealed no 3p loss by means of CGH, unlike most cases of conventional RCC that are seemingly associated with poor vasculature. In summary, to our knowledge, this is the first reported case of an unclassified RCC featuring a unique growth pattern composed of a mixed clear cell type without a 3p loss and a variant of CDC with a unique karyotypic alteration.     

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。     

Chromosomal imbalances in primary oligodendroglial tumors and their recurrences: clues about malignant progression detected using comparative genomic hybridization

OBJECT: Despite the rapid increase in knowledge concerning the genetic basis of malignant progression in astrocytic tumors, progression of oligodendroglial tumors (including both pure oligodendrogliomas and mixed oligoastrocytomas) is still poorly understood. The aim of the present study is the elucidation of chromosomal imbalances involved in the progression of oligodendroglial tumors toward malignancy. METHODS: Using comparative genomic hybridization (CGH) on snap-frozen tumor tissue, the tumor genomes of five primary oligodendroglial tumors and associated recurrent tumors were screened for chromosomal imbalances. This information was correlated with clinical data (including follow-up data) and histopathological malignancy grade. In all cases an increase in chromosomal imbalances was detected in the recurrent tumor, indicating genetic progression. In three of the five cases this correlated with malignant progression detected at the histopathological level. The results indicate that, similar to what occurs in astrocytic tumors, chromosomal imbalances harboring genes involved in the cell proliferation control mechanism at the G1-S border are involved in the progression of oligodendroglial tumors. Additionally, although gains of genetic material on chromosome 7 and losses on chromosome 10 are most frequently detected in the course of malignant progression of astrocytic tumors, either or both of these can also occur during malignant progression of typical oligodendroglial tumors that contain losses involving chromosome 1p and/or chromosome 19q. CONCLUSIONS: When performed on optimally preserved material from a small set of primary oligodendroglial tumors and associated recurrent tumors, CGH detects chromosomal aberrations that potentially play a mechanistic role in the malignant progression of these tumors.     

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.     

Genetic changes in pT2 and pT3 prostate cancer detected by comparative genomic hybridization

Prostate-specific antigen (PSA) screening has led to a remarkable increase in prostate cancer cases undergoing operative therapy. Over half of patients with locally advanced cancer (>or=pT3) develop rising PSA levels (biochemical failure) within 10 years. It is very difficult to predict which patients will progress rapidly to advanced disease following biochemical failure (BF). Therefore, a more useful prognostic factor is needed to suggest the most appropriate therapies for each patient. To determine chromosomal aberrations, we examined 30 patients with stage pT2 or pT3 primary prostate adenocarcinomas and no metastases (pN0M0) by comparative genomic hybridization (CGH). Laser capture microdissection (LCM) was used to gather cancer cells from frozen prostate specimens. Common chromosomal alterations included losses on 2q23-24, 4q26-28, 6q14-22, 8p12-22 and 13q21-31, as well as gains on 1p32-36, 6p21 and 17q21-22. Losses at 8p12-22 and 13q21-31 were observed more frequently in pT3 than pT2 tumors (P<0.05 and P<0.01, respectively). Losses at 8p12-22 were more frequent in tumors with BF (P<0.05), and those at 13q12-21 were more frequent in tumors with Gleason score (GS) 7 or more than lower GS (P<0.05). These findings suggest that losses of 8p12-22 and 13q21-31 are important determinants of prostate cancer progression.     

Chromosomal defects in renal cell carcinoma.

Numerous chromosomal defects have been identified in hereditary and sporadic renal cell carcinoma (RCC) tumor cells. Current data indicate that visible, and/or submicroscopic lesions on the 3p are fundamental to RCC development; other chromosomal abnormalities are identified less frequently and may be secondarily involved in RCC production in some cases. Oncogenesis may be initiated via inactivation of suppressor allele pairs, or through activation of oncogenes via translocation to areas of increased gene expression, migration to a chromosomal breakpoint, or gene amplification.     

Distinct array comparative genomic hybridization profiles in oral squamous cell carcinoma occurring in young patients

BACKGROUND: Oral cancer typically affects smokers older than 50 years of age. Recently, however, a marked increase in the number of patients 40 years old and younger, many with no history of tobacco smoking, has been noted. Studies in this age group have so far been restricted to genomic areas well recognized as abnormal in typical patients with oral cancer. The aim of this study was to assess genomic aberrations in oral cancer, using comparative genomic hybridization (CGH) microarray technology, and to compare the genomic aberration profile of patients older than 40 years old with those 40 years old and younger. METHODS: Tumor samples from 20 patients with oral cancer (age range, 21-78; 10 smokers and 10 nonsmokers) were laser microdissected, and array CGH was used to identify genomic imbalances in these two cohorts. RESULTS: The older cohort showed high numbers of gains and losses in contrast to very few copy number changes in the younger nonsmoker cohort. In concurrence with the literature, tumors from the older cohort manifested deletions involving 3p and 9p21 and gains involving 3q, 5q, 7p, 8q, 11q, and 20q. The younger group, particularly the nonsmokers, showed very few changes overall, and the aberrations were not in the sites classically associated with oral cancer. Deletion of CDKN2A (p16) was completely absent in the younger group but was present in 50% of the older cohort. CONCLUSIONS: We have demonstrated that there is far less genomic instability in young nonsmokers with oral cancer than found in typical patients with oral cancer. These observations indicate that oral cancer presenting at a younger age, particularly in nonsmokers, has a genomic profile different from the classically described oral cancer.     

Cytogenetic alterations in renal tumors. Applications for comparative genomic hybridization and fluorescence in situ hybridization

The WHO classification of renal cell carcinomas (RCC) takes into account chromosomal alterations. New cytogenetic techniques such as comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH) offer alternative methods to the classic cytogenetic banding technique. Clear cell (classic) RCC frequently show the loss of 3p. Papillary RCC are characterized by trisomies and tetrasomies as well as loss of the Y chromosome. CGH analysis demonstrates that DNA copy increase is more common in type I papillary RCC compared to type II. Chromophobe RCC are characterized by losses in chromosomes 1, 2, 6, 10, 13, 17, and 21. Oncocytomas can be divided into cases with rearrangements in the 11q13 region and those with loss of chromosome 1 and the sex chromosomes. Translocations involving chromosome 3, such as t(3;8)(p14;q24.13) and t(2;3)(q35;q21) have been described in familial clear cell RCC. The most recent class of RCC, seen only in men, is referred to as translocation tumors. These tumors demonstrate a tubulopapillary growth pattern and have a t(X;1)(p11.2;q21.2) translocation. Although not required for most clinical diagnoses, CGH and FISH complement the standard histologic diagnosis of RCC and may provide a definitive diagnosis in a small number of challenging cases.     

Cell proliferation in renal cell carcinoma — a comparative study of cell kinetic methods

Four different methods of assessing cell proliferation in renal cell carcinoma were compared in a total of 136 samples to analyze their degree of agreement and usefulness. The methods compared were flow cytometric S-phase (S-FCM) analysis, proliferating cell nuclear antigen expression detected by immunohistochemistry (PCNA-IHC), in vivo iododeoxyuridine incorporation analyzed with immunohistochemistry (IdUrd-IHC), and flow cytometry (IdUrd-FCM). The mean S-FCM fraction was 5.9%, compared with a mean PCNA-IHC labeling index of 4.7%. The mean labeling indices obtained by IdUrd-IHC and IdUrd-FCM were 1.2% and 1.7% respectively. The four methods correlated well with each other. When the methods were compared according to Bland and Altman, good agreement was shown. A statistically significant difference in proliferation between diploid and aneuploid tumor samples was found with all methods (P<0.001). The results showed that the four different methods provided comparable information on proliferative activity, although different cell cycle compartments were monitored.     

Asymptomatic renal cell carcinoma incidentally detected by abdominal CT

We reported two cases of renal cell carcinoma incidentally detected by abdominal CT during the evaluation of another clinical problem. They had no relevant symptoms of renal cell carcinoma. Case 1: The tumor was 32 X 33 X 34 mm. Histopathological diagnosis was clear cell subtype, tubular type greater than alveolar type, grade 1, INF alpha, pT2b, pV0, pNX, pM0. Case 2: The tumor was 20 X 20 X 16 mm. Histopathological diagnosis was clear cell subtype, alveolar type, grade 1, INF alpha, pT1, pV0, pNX, pM0.     

比较基因组杂交揭示骨肉瘤相关基因变异

比较基因组杂交是诊断肿瘤发生发展的方法,能够发现与骨肉瘤相关的基因变异,从而为基因治疗提供依据.通过比较基因组杂交发现骨肉瘤患者基因扩增多于缺失,经常发生变异的基因与骨肉瘤密切相关.4q变异是儿童骨肉瘤共同的畸变;8q扩增与骨肉瘤复发和侵袭性相关;17p扩增(除17p13.1外)与骨肉瘤恶性程度相关;凋亡相关因子与骨肉瘤发生发展、预后密切相关;环氧化酶-2在骨肉瘤的高表达为骨肉瘤新辅助化疗提供依据;高频的基因变异位点主要与癌基因、抑癌基因、细胞生长和细胞周期调控、细胞凋亡、端粒、细胞因子、肿瘤免疫、肿瘤血管生成、肿瘤转移相关因子等密切相关.     

Olfactory neuroblastoma: Detection of genomic imbalances by comparative genomic hybridization

Summary Olfactory neuroblastoma (esthesioneuroblastoma) is a very rare tumour of the olfactory mucosa. Morphological features and cytogenetic studies strongly suggest a neuro-ectodermal origin. Up to now, cytogenetic studies are inconsistent. Some of them have proposed that the tumour belongs to the pPNET family. In the present study we describe genomic imbalances in olfactory neuroblastoma in a 46-year-old woman by using the molecular cytogenetic technique — comparative genomic hybridization (CGH) — in order to define the spectrum of genetic abnormalities in the tumour. The anatomical location and morphological findings were the basis for the diagnosis of esthesioneuroblastoma. Immunohistochemical reactions for NSE, synaptophysin, chromogranin A, HNK-l/Leu-7 and S-100 revealed a characteristic immunophenotype. The CGH analysis showed multiple changes including DNA overrepresentations of chromosomes 4. 8, 11 and 14, partial DNA gains of the long arms of chromosomes 1 and 17, deletions of the entire chromosomes 16, 18. 19 and X, and partial losses of chromosomes 5q and 17p. This study represents an early utilisation of the CGH technique in olfactory neuroblastoma and demonstrates that the tumour carries complex chromosomal aberrations.     

Genetic changes in familial prostate cancer by comparative genomic hybridization

BACKGROUND: Germline mutations in recessive cancer predisposition genes are uncovered by somatic genetic deletions during tumor development. Analysis of genetic changes in tumor tissues from patients with an inherited predisposition may therefore highlight regions of the genome containing susceptibility or modifier genes. Our aim was to characterize genetic changes in familial prostate cancer METHODS: Twenty-one primary prostate cancers from 19 Finnish prostate cancer families were analyzed for somatic genetic changes by comparative genomic hybridization (CGH). RESULTS: The average number of genetic alterations per tumor was 4.0 +/- 1.9, distributed equally among losses and gains. The most common losses were found at chromosomal regions 13q14-q22 (29%), 8p12-pter (24%), and 6q13-q16 (14%), and the most common gains at 19p (25%), 19q (14%) and 7q (14%). CONCLUSIONS: These results suggest that prostate cancers in genetically predisposed individuals arise for the most part through similar somatic genetic progression pathways as sporadic prostate cancers. This also implies that the biological properties of tumors from the two groups may not be different from one another.     

单细胞微阵列比较基因组杂交技术在胚胎植入前遗传学筛查中的应用

目的 建立利用单细胞微阵列比较基因组杂交(array CGH,aCGH)技术进行胚胎植入前遗传学筛查(PGS)技术平台,并应用aCGH技术进行PGS获得持续妊娠. 方法 采集废弃胚胎来源卵裂球10个,核型正常男性(46,XY)淋巴细胞3个,通过单细胞全基因组扩增后,利用aCGH技术进行染色体非整倍体分析;在此基础上,将aCGH技术应用于临床一例反复流产患者. 结果 3个淋巴细胞及9个废胚来源卵裂球的全基因组扩增成功,1个废胚来源卵裂球扩增失败,扩增成功的样本通过aCGH检测后均获得明确的诊断,3个淋巴细胞分析结果与已知核型一致;临床病例5个胚胎活检的单卵裂球均得到明确诊断,移植1枚正常整倍体胚胎后获得临床持续妊娠. 结论 在胚胎植入前遗传学筛查中,单细胞aCGH技术能全面地评估胚胎染色体组情况,可应用于临床PGS.     

Incidence and properties of renal masses and asymptomatic renal cell carcinoma detected by abdominal ultrasonography

Renal ultrasonography was performed in 45,905 adults, including 41,364 without any signs suggesting urinary tract malignancies, 1,667 with microscopic hematuria only and 2,874 with some signs of malignancy. Renal lesions were found in 355 adults (0.858%) in the asymptomatic, 39 (2.3%) in the microscopic hematuria and 75 (2.6%) in the symptomatic groups, respectively. Renal cell carcinoma was found in 35 (7.5%) lesions: 19 (5.4%) in the asymptomatic, none in the microscopic hematuria and 16 (21.3%) in the symptomatic groups. A total of 47 patients, including 12 other renal cell carcinoma patients transferred from related hospitals, was grouped into 28 without and 19 with symptoms. Primary tumor size and clinical stages were significantly smaller and lower, respectively, in the asymptomatic group than in the symptomatic group. Radical nephrectomy was performed in all but 2 asymptomatic patients. The 5-year survival rates after nephrectomy were 94.7 and 60.9% for the asymptomatic and symptomatic groups, respectively (p less than 0.01). The results indicate that ultrasonography is a useful tool to detect low stage asymptomatic renal cell carcinoma at low cost.     

Detection of chromosomal imbalances in spinal meningiomas by comparative genomic hybridization

Little is known about genetic mutations during the malignant progression of spinal meningiomas. This study investigated genomic changes across the entire genome in spinal meningioma samples to determine possible mechanism(s) of tumorigenesis. Paraffin-embedded tissue sections of 16 spinal meningiomas were analyzed by the comparative genomic hybridization (CGH) technique. Lymphocytes of the patients were evaluated as controls. Genomic change was detected in 11 samples. Complete or partial loss of chromosome 22 was the most commonly seen abnormality in eight cases. Chromosome losses on 1p, 9p, and 10q and gains on 5p and 17q were the other abnormalities. These changes are all frequently seen in meningiomas, but are mostly specific to atypical and anaplastic meningiomas. However, in the present study, copy number changes on chromosomes 9p (3 samples), 17q (2 samples), and 1p (2 samples) were seen even in the benign tumors. Our results suggest that in addition to the neurofibromatosis type 2 tumor suppressor gene, other cancer-related genes located on 1p, 9p, 10q, and 17q might be involved in the etiology of spinal meningiomas.