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Biomedical subjects

J Bruch

Publications and source records attributed to J Bruch.

At least 19 recordsLinked to original sources

Loss of heterozygosity on chromosome 6q14-q24 is associated with poor outcome in children and adolescents with T-cell lymphoblastic lymphoma.

Deletions of chromosome 6q have been reported in several hematological malignancies, but data are not conclusive regarding their biological and prognostic impact. Therefore, we focused on pediatric patients diagnosed with T-cell lymphoblastic lymphoma (T-LBL) treated uniformly according to the NHL-BFM95 protocol. We used loss-of-heterozygosity (LOH) analysis of 25 microsatellite markers located on chromosome 6q14-q24. Fragment-length analysis was performed on ABI-PRISM3100 Genetic-Analyzer. Eligibility criterion was > or =3 informative markers. Between April 1995 and March 2003, 185 T-LBL patients were treated according to the NHL-BFM95 protocol. Five-year event-free (EFS) and disease-free survival (DFS) were 79+/-3 and 87+/-3% (median follow-up 4.7 [1.2-10.1] years). Sixty-one patients were evaluable for LOH analysis, including 18 out of 23 patients with relapse. EFS and DFS were 67+/-6 and 69+/-6% for these 61 patients. Testing of 853 markers in the 61 patients identified the presence of LOH in 19 patients (31%): 13 of the 18 relapse patients and five of the 41 in complete remission (odds ratio 18.7, 95% confidence interval 4.7-75.3). One LOH-positive patient died from treatment-related toxicity. We conclude that LOH on chromosome 6q14-q24 may have conferred a high risk of relapse on our group of children with T-LBL treated according to the NHL-BFM95 protocol.

Adolescent↗

Inactivation of the ARF-MDM-2-p53 pathway in sporadic Burkitt's lymphoma in children.

Burkitt's lymphomas (BLs) are characterized by an activated MYC gene that provides a constitutive proliferative signal. However, activated myc can initiate ARF-dependent activation of p53 and apoptosis as well. Data derived from cell culture and animal models suggest that the inactivation of the ARF-MDM-2-p53 apoptotic signaling pathway may be a necessary secondary event for the development of BL. This has not been tested in freshly excised BL tissue. We investigated the ARF-MDM-2-p53 pathway in tumor specimen from 24 children with sporadic BL/B-ALL. Direct sequencing revealed a point mutation in the p53 gene in four BL. Overexpression of MDM-2 was evident in 10 of the BL samples analyzed by real-time quantitative PCR. Deletion of the CDKN2A locus that encodes ARF or reduced expression of ARF could not be detected in any BL by fluorescence in situ hybridization analysis or real-time quantitative PCR, respectively. Our results indicate that the ARF-MDM-2-p53 apoptotic pathway is disrupted in about 55% of the cases of childhood sporadic BL. We suggest that in addition to the inactivation of the ARF-MDM-2-p53 protective checkpoint function other antiapoptotic mutations may occur in a substantial part of children with sporadic BL.

Adolescent↗

Different toxic, fibrogenic and mutagenic effects of four commercial quartz flours in the rat lung.

There is still intensive debate on the variability in the biological activities of different quartz species. Therefore we examined in a rat lung model the inflammatory, fibrogenic and genotoxic characteristics of four commercial quartz flours. The samples, two with probably low activity and two with probably high activity were selected from a panel of 16 samples on the basis of in vitro investigations. Rats were exposed by a single intratracheal injection of 0.6, 1.2 and 2.4 mg quartz samples per lung or with 1.2 mg standard quartz DQ12. After 90 days the inflammatory response was measured in the bronchoalveolar lavage fluid, as well as the content of 8-oxoguanine in the DNA of the lung cells. Additionally mutated p53 protein was determined. The four quartz samples revealed specific differences in all parameters investigated. In good agreement with the in vitro results the two samples expected as lowly active showed only weak inflammatory and no genotoxic reactions in the rat lungs. In contrast the two samples suspected as highly reactive induced a pronounced inflammatory response and for one of the samples genotoxic effects could be proven. The results raised here show a broad spectrum of biological activities dependent on the type of quartz from almost inert to genotoxic and highly inflammatory.

Animals↗

Investigations on the inflammatory and genotoxic lung effects of two types of titanium dioxide: untreated and surface treated.

TiO(2) is considered to be toxicologically inert, at least under nonoverload conditions. To study if there are differences in lung effects of surface treated or untreated TiO(2) we investigated the inflammatory and genotoxic lung effects of two types of commercially available TiO(2) at low doses relevant to the working environment. Rats were exposed by instillation to a single dose of 0.15, 0.3, 0.6, and 1.2 mg of TiO(2) P25 (untreated, hydrophilic surface) or TiO(2) T805 (silanized, hydrophobic surface) particles, suspended in 0.2 ml of physiological saline supplemented with 0.25% lecithin. As control, animals were instilled with the vehicle medium only or with a single dose of 0.6 mg quartz DQ12. At days 3, 21, and 90 after instillation bronchoalveolar lavage was performed and inflammatory signs such as cells, protein, tumor necrosis factor-alpha, fibronectin, and surfactant phospholipids were determined. Additionally, 8 microm frozen sections of the left lobe of the lung were cut and stored at -80 degrees C. The sections were used for immunohistochemical detection of 8-oxoguanine (8-oxoGua) by a polyclonal antibody in the DNA of individual lung cells. In the quartz-exposed animals a strong progression in the lung inflammatory response was observed. Ninety days after exposure a significant increase in the amount of 8-oxoGua in DNA of lung cells was detected. In contrast, animals exposed to TiO(2) P25 or TiO(2) T805 showed no signs of inflammation. The amount of 8-oxoGua as a marker of DNA damage was at the level of control. The results indicate that both types of TiO(2) are inert at applicated doses.

Air Pollutants, Occupational↗

Monitoring of minimal residual disease (MRD) by real-time quantitative reverse transcription PCR (RQ-RT-PCR) in childhood acute myeloid leukemia with AML1/ETO rearrangement.

The fusion transcript AML1/ETO corresponding to translocation t(8;21)(q22;q22) can be found in approximately 7-12% of childhood de novo AML. Despite the favorable prognosis, some of these patients relapse. Most of MRD studies so far were performed on adults treated not uniformly. Therefore, we analyzed the follow-up of 15 AML1/ETO-positive children using real-time quantitative reverse transcription PCR (RQ-RT-PCR), all enrolled in the multicenter therapy trial AML-BFM 98. AML1/ETO copy numbers were normalized to the control gene ABL and the results were expressed in copy numbers AML1/ETO per 10 000 copies ABL. At diagnosis, a median of 10 789 copies AML1/ETO was found. A linear decrease to about 10 copies (2-4 log) could be seen in most of the children by the start of consolidation. In the majority of cases they remained positive at this low level during the ongoing therapy. Four children relapsed and two of them had a decrease of less than 2 log before starting consolidation. Three of the relapsed children showed, prior to relapse, an increase of the AML1/ETO fusion transcript at 6, 9, and 11 weeks, respectively. These results suggest that monitoring of minimal residual disease using RQ-RT-PCR could be helpful in detecting patients with a higher risk of relapse.

Adolescent↗

[Occupational lead poisoning due to deficient protective measures at the work place].

UNLABELLED: Occupational lead poisoning due to deficient protective measures at the work place. HISTORY AND ADMISSION FINDINGS: A 27-year-old man who was working in the mixing plant of a company manufacturing synthetic materials, was admitted with colicky upper abdominal pain, loss of appetite and postprandial nausea for 3 weeks. On examination he had pain without guarding over the abdomen. INVESTIGATIONS: He had a normochronic anaemia (haemoglobin 12.5. g/dl). Ultrasound of the abdomen revealed splenomegaly. Gastroscopy excluded an ulcer. Deep duodenal biopsy showed Giardia intestinalis histologically. DIAGNOSIS, TREATMENT AND COURSE: As part of the differential diagnosis of abdominal colic and anaemia, lead poisoning was found, with the lead level markedly elevated to 1776 microgram/l. Penicillamine treatment rapidly reduced the blood lead level, but it had not yet become normal after 4 months. Exposure to lead at his work place was discovered. Subsequent tests there by the federal agency for occupational protection revealed massive deficiencies in protective measures. CONCLUSION: In present conditions abdominal colic must be viewed as a cardinal symptom of lead poisoning. Blood levels must be obtained as part of the differential diagnosis of abdominal pain of uncertain aetiology. If the diagnosis has been established and an occupational risk is possible, the appropriate occupational organizations and, if necessary, federal agency must be informed in order to exclude occupational exposure to lead. In Germany there still exist marked deficiencies in the protection of workers occupationally exposed to lead. Notification is essential to protect others similarly at risk.

Adult↗

Clonal chromosomal aberrations in simian virus 40-transfected human thyroid cells and in derived tumors developed after in vitro irradiation.

In vitro model cell systems are important tools for studying mechanisms of radiation-induced neoplastic transformation of human epithelial cells. In our study, the human thyroid epithelial cell line HTori-3 was analyzed cytogenetically following exposure to different doses of alpha- and gamma-irradiation and subsequent tumor formation in athymic nude mice. Combining results from G-banding, comparative genomic hybridization, and spectral karyotyping, chromosome abnormalities could be depicted in the parental line HTori-3 and in nine different HTori lines established from the developed tumors. A number of chromosomal aberrations were found to be characteristic for simian virus 40 immortalization and/or radiation-induced transformation of human thyroid epithelial cells. Common chromosomal changes in cell lines originating from different irradiation experiments were loss of 8q23 and 13cen-q21 as well as gain of 1q32-qter and 2q11.2-q14.1. By comparison of chromosomal aberrations in cell lines exhibiting a different tumorigenic behavior, cytogenetic markers important for the tumorigenic process were studied. It appeared that deletions on chromosomes 9q32-q34 and 7q21-q31 as well as an increased copy number of chromosome 20 were important for the tumorigenic phenotype. A comparative breakpoint analysis of the marker chromosomes found and those observed in radiation-induced childhood thyroid tumors from Belarus revealed a coincidence for a number of chromosome bands. Thus, the data support the usefulness of the established cell system as an in vitro model to study important steps during radiation-induced malignant transformation in human thyroid cells.

Animals↗

Evidence of a no-effect level in silica-induced rat lung mutagenicity but not in fibrogenicity.

Exposure to silica can lead to fibrosis and the development of lung tumors in the rat. Based on these animal studies and on epidemiological data, silica has been classified as a human carcinogen. The initial mechanisms have not been finally clarified, but particle-induced tumor formation is at least closely associated with inflammation, the production of reactive oxygen species (ROS) and DNA damage. We investigated the dose-dependent effects of silica on the formation of the major DNA oxidation product 8-oxoguanine (8-oxo-Gua) in rat lung cells, on p53 (p53) and p53 mutant protein (p53 mut) synthesis, as well as on the amount of the surfactant phospholipids phosphatidylinositol (PI) and phosphatidylglycerol (PG) in the bronchoalveolar lavage fluids (BALF) as indicators of fibrotic processes in the lung. Rats were exposed by intratracheal instillation to various amounts of DQ12 quartz (0.15, 0.3, 0.6, 1.2, 2.4 mg/animal) and lungs were investigated after 21 and 90 days. PG decreased and PI increased quartz dose dependently. 8-oxoGua was significantly increased only after 1.2 and 2.4 mg quartz/animal. Cells expressing p53 protein were increased at 1.2 and 2.4 mg, p53 mutant protein only at 2.4 mg/animal. This indicates a no-effect level for mutagenicity at a low, but still fibrogenic quartz exposure.

Animals↗

Quartz exposure of the rat lung leads to a linear dose response in inflammation but not in oxidative DNA damage and mutagenicity.

Exposure to quartz and high concentrations of other poorly soluble particles can lead to the development of lung tumors in the rat. The mechanisms involved in particle-induced carcinogenesis seem to include inflammation-associated production of reactive oxygen species (ROS) and DNA damage. ROS induce 8-oxoguanine (8-oxoGua) and a panel of other oxidation products in DNA. In proliferating cells such DNA lesions can lead to various types of mutations, which might be critical for cancer-related genes with respect to tumor formation. Quartz is known to mediate the induction of 8-oxoGua in the nuclear DNA of lung cells when applied to the lung of rats. We have investigated the time- and dose-dependent biologic effects of quartz and, as a control, corundum, on cell proliferation and various pulmonary inflammation and toxicity markers in rat bronchoalveolar lavage fluid (BALF); on the induction of 8-oxoGua in the DNA of rat lung cells; and on the cellular levels of p53 wild-type and p53 mutant (mut) protein. Rats were exposed by intratracheal instillation to various amounts of quartz (0.3, 1.5, or 7.5 mg/rat) or corundum (0.3, 1.5, or 7.5 mg/rat) and measured at Days 7, 21, and 90 after exposure. Corundum had no adverse effects except a slight elevation of 8-oxoGua at a dose of 7.5 mg/rat. However, significant changes in the BALF were detected at all quartz doses. 8-oxoGua was significantly increased only at 1.5 and 7.5 mg quartz/rat. The amount of cells with detectable p53 wild-type protein levels was increased at 1.5 and 7.5 mg quartz/rat at 7 and 21 d. Elevated amounts of cells with enhanced p53 mut protein levels were measured at all time points after instillation of 7.5 mg quartz/rat.

Aluminum Oxide↗

Neoplastic transformation and cytogenetic changes after Gamma irradiation of human epithelial cells expressing telomerase.

Neoplastic transformation of human epithelial cells by radiation has previously been investigated using cell lines immortalized with viral vectors. There are disadvantages to this approach, and we report here the results of studies using a human retinal pigment epithelial cell line (340RPE-T53) immortalized by treatment with telomerase. After exposure of the cells to fractionated doses of gamma radiation, there was a marked increase in anchorage-independent growth of the surviving cells. The cloned cell lines derived from these anchorage-independent cultures exhibited an increased growth rate in vitro and were serum-independent compared with the parent cell line. The parent cell line maintained a stable diploid karyotype. The cell lines cloned after irradiation with the lower doses (10 x 2 Gy) were hypodiploid with loss of chromosome 13 and a high level amplification of 10p11.2 associated with a deletion of the remaining short arm segment of chromosome 10 distal to 10p11.2. In contrast, the cell lines cloned after irradiation with the higher doses (15 x 2 Gy) were near-tetraploid with derivative chromosomes present characterized by SKY analysis. Thus this human epithelial cell line immortalized with telomerase provides an improved model to investigate mechanisms of radiation carcinogenesis.

Cell Adhesion↗

Delineation of the 6p22 amplification unit in urinary bladder carcinoma cell lines.

Eight cell lines from transitional cell carcinoma of the urinary bladder were analyzed by comparative genomic hybridization. All tumor lines exhibited frequent chromosome gains (11.5/cell line) and losses (8.4/cell line). In six cell lines, gain of chromosome 5p was associated with gains of 6p and 20q. In five of these cell lines, amplification of parts of 6p was observed. Cytogenetic investigation combined with fluorescence in situ hybridization analysis revealed typical marker chromosomes with homogeneously staining regions (HSRs) containing material from 6p. By hybridizing individual yeast artificial chromosome probes from a chromosome 6p contig to these HSRs, a contig of three yeast artificial chromosomes common to all 6p HSRs was identified that spans less than 2 Mb. The genes SOX4 and PRL were shown to map to this region and to be coamplified in the cell lines. However, SOX4 was not overexpressed in any cell line and PRL was not expressed at all. Thus, the presumptive 6p oncogene remains to be conclusively identified.

Carcinoma, Transitional Cell↗

Translocation t(10;14)(q11.2:q22.1) fusing the kinetin to the RET gene creates a novel rearranged form (PTC8) of the RET proto-oncogene in radiation-induced childhood papillary thyroid carcinoma.

Evaluation of 20 cases of radiation-induced childhood papillary thyroid carcinoma using fluorescence in situ hybridization demonstrated the presence of clonal translocations affecting the RET locus. Semiquantitative reverse transcription-PCR indicated overexpression of the RET tyrosine kinase (TK) domain in four cases. In two cases, the RET rearrangements PTC6 and PTC7 were identified and assigned to balanced translocations t(7;10)(q32;q11.2) and t(1;10)(p13;q11.2), respectively. In one case with a balanced translocation t(10;14)(q11.2;q22.1), 5' rapid amplification of cDNA ends revealed a novel type of RET oncogenic activation (PTC8), arising from a fusion of the 5' part of the kinectin (KTN1) gene to the TK domain of the RET gene. The presence of coiled-coil domains in the resulting ktn1/ret fusion protein suggests ligand-independent dimerization and thus constitutive activation of the ret TK domain.

Base Sequence↗

Biomarkers of genetic damage and inflammation in blood and bronchoalveolar lavage fluid among former German uranium miners: a pilot study.

Former East German uranium miners who are known to have been exposed to radon are estimated to be at high risk for lung carcinogenesis. Among these miners over 200 occupationally caused lung cancer cases are expected to occur each year, resulting in a total of 7,000-24,000 excess lung cancer cases in the coming years. It is still unknown whether there is a correlation between biomarkers and the exposure of the uranium miners to ionizing radiation that might enable us to trace those miners with high lung cancer risk. The primary aim of this pilot study was to test the possibility of performing a biomarker study in this unique cohort of former uranium miners in spite of several limitations that had to be taken into consideration when comparing them with healthy controls, such as old age, age-dependent diseases and potential confounding artefacts from dissimilar smoking patterns. The second aim was to test a range of biomarkers for DNA damage and inflammation in leukocytes and bronchoalveolar fluid for their ability to detect biological effects. In this cohort of miners we found an increased frequency of chromosomal aberrations in blood lymphocytes and an increased prevalence of both fibronectin and tumour necrosis factor alpha in the bronchoalveolar fluid.

Aged↗

Chromosomal imbalances in Barrett's adenocarcinoma and the metaplasia-dysplasia-carcinoma sequence.

To characterize cytogenetic alterations found in Barrett's adenocarcinoma (BA) and, more importantly, its premalignant stages, we studied chromosomal imbalances in various lesions in the histologically proposed metaplasia-dysplasia-carcinoma sequence using comparative genomic hybridization (CGH). Using 30 esophageal adenocarcinoma resection specimens, we were able to study 30 areas of Barrett's adenocarcinoma and 8 lymph node metastases (LN). In addition, we investigated 25 premalignant lesions adjacent to BA derived from a subset of 14 resection specimens including 11 areas of high grade dysplasia (HGD), 8 areas of low grade dysplasia (LGD), and 6 areas of intestinal metaplasia (IM), which were laser-microdissected and studied with CGH. To validate the CGH findings, fluorescence in situ hybridization analysis on 13 BA with probes specific for HER-2/neu and 20q13.2 were performed. The chromosomal alterations most often identified in BA were: gains on 8q (80%), 20q (60%), 2p, 7p and 10q (47% each), 6p (37%), 15q (33%) and 17q (30%). Losses were observed predominantly on the Y-chromosome (76%), 4q (50%), 5q and 9p (43% each), 18q (40%), 7q (33%) and 14q (30%). High-level amplifications were observed on 8q23-qter, 8p12-pter, 7p11-p14, 7q21-31, 17q11-q23. Recurrent chromosomal changes were also identified in metaplastic (gains on 8q, 6p, 10q, losses on 13q, Y, 9p) and dysplastic epithelium (gains on 8q, 20q, 2p, 10q, 15q, losses on Y, 5q, 9p, 13q, 18q). Novel amplified chromosomal regions on chromosomes 2p and 10q were detected in both Barrett's adenocarcinoma and premalignant lesions. An increase of the average number of detected chromosomal imbalances from IM (7.0 +/- 1.7), to LGD (10.8 +/- 2.2), HGD (13.4 +/- 1.1), BA (13.3 +/- 1.4), and LN (22 +/- 1.2) was seen. Although the detection of common chromosomal alterations in premalignant lesions and adjacent carcinomas suggest a process of clonal expansion, the occurrence of several chromosomal changes in an apparently random order relative to one another is striking evidence that clonal evolution is more complex than would be predicted by linear models. This is probably a reflection of the existence of many divergent neoplastic subpopulations and highlights one of the main problems associated with surveillance of Barrett's patients, namely sampling error.

Adenocarcinoma↗

Molecular genetic changes in metastatic primary Barrett's adenocarcinoma and related lymph node metastases: comparison with nonmetastatic Barrett's adenocarcinoma.

Lymph node metastasis is one of the strongest negative prognostic factors for patients with Barrett's adenocarcinoma (BCA). However, despite the importance of the metastatic process in BCA, the molecular basis of it remains poorly understood. To search for cytogenetic events associated with metastasis in regional or distant lymph nodes in BCA, we investigated 8 primary BCA and their lymph node metastases and compared them with 18 nonmetastatic BCA. In metastatic primary BCA, we observed significantly more DNA gains on 3q (P = .013), 17q (P = .019), and 22q (P = .021) compared with nonmetastatic primary BCA. No statistically significant correlation could be observed between DNA copy number changes and the histopathologic stage, grade, or survival (P > .05). The most frequent alteration observed only in lymph node metastases but not in the related primary tumor was loss of 2q (5 of 8). Coamplification of 7p and chromosome 17 was found in 6 of 8 lymph node metastases. A comparison of DNA copy number changes between primary tumors and their corresponding metastases indicated a high degree of genetic heterogeneity. Fluorescence in situ hybridization analysis demonstrated the involvement of the Her-2/neu gene in primary BCA and its related lymph node metastases. Each of the investigated primary tumors and related lymph node metastases also showed striking heterogeneity with respect to Her-2/neu, with several areas displaying different levels of amplification. In summary, our data indicate that DNA copy number changes on 2q, 3q, 7p, 17q, and 22q may be involved in the metastatic process in BCA. Furthermore, the striking genetic heterogeneity that we found between primary BCA and its lymph node metastases may underlie BCA's poor responsiveness to therapy and could help explain why prognostic biomarkers measured exclusively in primary tumors give an incomplete view of the biologic potential of BCA.

Adenocarcinoma↗

Detailed marker chromosome analysis in cell line U-BLC1, established from transitional-cell carcinoma of the bladder.

A permanent cell line, U-BLC1, was established from a primary transitional-cell carcinoma, TCC, of the urinary bladder. Karyotype analysis showed the line to be highly aberrant, with a near-triploid chromosome number of 68 to 73. Comparative genomic hybridization revealed some distinct differences between the primary tumor and the established cell line. Karyotype analysis showed 3 marker chromosomes with homogeneously staining regions, HSRs, in the cell line. The HSRs were isolated by microdissection and the microdissection probes were hybridized to normal metaphase chromosomes. The HSRs contain sequences known to be frequently involved in amplification in transitional-cell carcinoma of the bladder, 6p22, 7p11-p12, 9p23-pter, and one region not yet reported to be amplified in primary TCC of the bladder, 1p31-p32. A candidate-gene approach showed that in the region 7p11-p12 the EGFR locus is amplified and highly expressed.

Aged↗

Neutrophils cause oxidative DNA damage in alveolar epithelial cells.

Inflammation has been recognized as a contributing factor in the pathogenesis of some cancers. In the lung, inflammation is characterized by an influx of polymorphonuclear leukocytes (PMN) that release a variety of reactive oxygen species (ROS). The aim of the present study was to investigate the direct effect of PMN on oxidative DNA damage in lung target cells. Therefore, rat alveolar epithelial cells (RLE) were coincubated with PMN or hydrogen peroxide. Known to be correlated with the incidence of cancer, 7-hydro-8-oxo-2'deoxyguanosine (8-oxodG) was used as an effect marker for oxidative damage. Viability of the RLE, when coincubated with PMN, decreased to 43%, dependent on the ratio between PMN and RLE. After washing off PMN, 8-oxodG levels were significantly increased in RLE, but the highest levels were observed in the washed off PMN fraction. In addition, to avoid washing off procedures, immunohistochemical analysis was used to measure the 8-oxodG levels specifically in the RLE and similar results were obtained. In addition, inhibitor experiments showed that antioxidants ameliorated oxidative DNA damage. Our data provide evidence that ROS released by PMN as well as H2O2, cause oxidative DNA damage in epithelial cells.

Animals↗

Chromosomal changes during progression of transitional cell carcinoma of the bladder and delineation of the amplified interval on chromosome arm 8q.

The cascade of genetic alterations leading to malignant transformation has been described for adenocarcinoma of the colon but is not established for other common tumor entities. In the present study, different stages of transitional cell carcinoma (TCC) of the bladder are analyzed by comparative genomic hybridization. A dynamic pattern of the chromosomal changes during tumor progression is described. Deletion of chromosome arm 9q is the earliest genetic alteration in pTa tumors. In stage pT1 carcinomas, losses of 9q, 9p, and 11p and gain of 1q and 8q are the most common. In addition to the changes specific for earlier stages, gain of 5p and 20q becomes prominent in carcinomas stage > or =pT2. Association analysis reveals a remarkable cooccurrence of 9p deletion with gain of 5p and 20q in > or =pT2 tumors. In order to determine more precisely the size of the amplified segment and the degree of amplification on chromosome arm 8q in stage pT1 tumors, this region was analyzed by semiquantitative PCR using polymorphic microsatellite markers. These studies revealed an up to 13-fold amplification. The common region of amplification could be narrowed down to 8q22.3 and between GAAT1A4 and D8S1834 (about 7 cM).

Carcinoma, Transitional Cell↗