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Brust P, Haubner R, Friedrich A, Scheunemann M, Anton M, Koufaki ON, Hauses M, Noll S, Noll B, Haberkorn U, Schackert G, Schackert HK, Avril N, Johannsen B. Comparison of [18F]FHPG and [124/125I]FIAU for imaging herpes simplex virus type 1 thymidine kinase gene expression. EUROPEAN JOURNAL OF NUCLEAR MEDICINE 2001; 28:721-9. [PMID: 11440032 DOI: 10.1007/s002590100526] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Various radiotracers based on uracil nucleosides (e.g. [124I]2'-fluoro-2'-deoxy-5-iodo-1-beta-D-arabinofuranosyluracil, [124I]FIAU) and acycloguanosine derivatives (e.g. [18F]9-[(3-fluoro-1-hydroxy-2-propoxy) methyl] guanine, [18F]FHPG) have been proposed for the non-invasive imaging of herpes simplex virus type 1 thymidine kinase (HSV1-tk) reporter gene expression. However, these radiotracers have been evaluated in different in vitro and in vivo models, precluding a direct comparison. Therefore, we directly compared [18F]FHPG and radioiodinated FIAU to assess their potential for PET imaging of transgene expression. The uptake of [125I]FIAU, [18F]FHPG and [3H]acyclovir was determined in vitro using four different HSV1-tk expressing cell lines and their respective negative controls. The in vitro tracer uptake was generally low in non-transduced parental cell lines. In HSV1-tk expressing cells, [3H]acyclovir showed approximately a twofold higher tracer accumulation, the [18F]FHPG uptake increased by about sixfold and the [125I]FIAU accumulation increased by about 28-fold after 120-min incubation of T1115 human glioblastoma cells. Similar results were found in the other cell lines. In addition, biodistribution and positron emission tomography (PET) studies with [18F]FHPG and [124/125I]FIAU were carried out in tumour-bearing BALB/c mice. Significantly higher specific accumulation of radioactivity was found for [125I]FIAU compared with [18F]FHPG. The ratio of specific tracer accumulation between [125I]FIAU and [18F]FHPG increased from 21 (30 min p.i.) to 119 (4 h p.i.). PET imaging, using [124I]FIAU, clearly visualised and delineated HSV1-tk expressing tumours, whereas only a negligible uptake of [18F]FHPG was observed. This study demonstrated that in vitro and in vivo, the radioiodinated uracil nucleoside FIAU has a significantly higher specific accumulation than the acycloguanosine derivative [18F]FHPG. This suggests that [124I]FIAU should be the preferred reporter probe for PET imaging of HSV1-tk gene expression. Thus, further attempts to develop suitable PET tracers for the assessment of HSV1-tk gene expression should also focus on 18F-labelled uracil derivatives.
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Noll B, Noll S, Grote M, Scheunemann M, Brust P, Friedrich A, Hauses M, Schackert HK, Johannsen B. Synthesis and preliminary evaluation of N1-methyl-9-[(1-hydroxy-3-[18F]fluoro-2-propoxy)methyl]guanine [18F]MFHPG, a new substrate of HSV-1-thymidine kinase. J Labelled Comp Radiopharm 2001. [DOI: 10.1002/jlcr.25804401155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Krex D, Mohr B, Hauses M, Ehninger G, Schackert HK, Schackert G. Identification of uncommon chromosomal aberrations in the neuroglioma cell line H4 by spectral karyotyping. J Neurooncol 2001; 52:119-28. [PMID: 11508811 DOI: 10.1023/a:1010680920087] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
To elucidate the reasons why mRNA expression of the LGI1 candidate tumor-suppressor gene was severely reduced in the glioma-derived cell line H4, as demonstrated in a previous study, we performed a cytogenetic analysis of this cell line using conventional methods and fluorescence in situ hybridization (FISH) techniques [spectral karyotyping (SKY), interphase- and chromosome FISH of metaphases (I- and C-FISH)]. Cell line H4 is monoclonal and near triploid (+/-3n). SKY enabled us to detect 24 structural aberrations: unbalanced translocations, n = 12; deletions, n = 10; insertion, n = 1; duplication, n = 1. The results were confirmed by I- and C-FISH analysis using chromosome-specific paints, centromer-specific probes and locus-specific probes for p53, PTEN/MMAC1, LGI1, Cyclin D1, EGR1, ETV6/TEL, AML1, and the genomic region 13q14.3 containing the Rb locus. We found loss of one copy of p53 as well as of one copy of Rb. Complete loss of PTEN/MMAC1 was detected, while all copies of LGI1 and Cyclin D1 were preserved. Interestingly, there was a gain of ETV6/TEL and EGR1, which were each present in quadruplicate. Additionally, the AML1 locus revealed mosaicism of cells with three and four copies, respectively. Additionally, a 5q-chromosome [del(5)(q13q33)] was found, which is one of the common features in hematological malignancies, and der(12)t(1;12) was found, suggesting that there might be an additional ETV6/TEL fusion protein. The combination of SKY, I- and C-FISH demonstrates that the neuroglioma cell line H4 harbors cytogenetic aberrations that are reported to occur in glioma-derived cell lines and additional chromosomal aberrations that have so far not been reported to occur in these cell lines. The complex aberrant karyotype and possibly generation of transcription factors by fusion proteins might be reasons for the impaired mRNA expression of the LGI1 candidate tumor-suppressor gene in cell line H4.
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Holinski-Feder E, Müller-Koch Y, Friedl W, Moeslein G, Keller G, Plaschke J, Ballhausen W, Gross M, Baldwin-Jedele K, Jungck M, Mangold E, Vogelsang H, Schackert HK, Lohsea P, Murken J, Meitinger T. DHPLC mutation analysis of the hereditary nonpolyposis colon cancer (HNPCC) genes hMLH1 and hMSH2. JOURNAL OF BIOCHEMICAL AND BIOPHYSICAL METHODS 2001; 47:21-32. [PMID: 11179758 DOI: 10.1016/s0165-022x(00)00148-2] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Denaturing high-performance liquid chromatography (DHPLC) is an efficient method for detection of mutations involving a single or few numbers of nucleotides, and it has been successfully used for mutation detection in disease-related genes. Colorectal cancer is one of the most common cancers, and mutations in the genes for hereditary nonpolyposis colon cancer (HNPCC), hMLH1 and hMSH2, also involve mainly point mutations. Sequence analysis is supposed to be a screening method with high sensitivity; however, it is time-consuming and expensive. We therefore decided to test sensitivity and reproducibility of DHPLC for 71 sequence variants in hMLH1 and hMSH2 initially found by sequence analysis in DNA samples of German HNPCC patients. DHPLC conditions of the PCR products were based on the melting pattern of the wild-type sequence of the corresponding PCR fragments. All but one of the 71 mutations was detected using DHPLC (sensitivity of 97%). Running time per sample averaged only 7 min, and the system is highly automated. Thus DHPLC is a rapid and sensitive method for the detection of hMLH1 and hMSH2 sequence variants.
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Pistorius SR, Kruppa C, Haas S, Plaschke J, Kruger S, Bulitta CJ, Nagel M, Saeger HD, Schackert HK. Clinical consequences of molecular diagnosis in families with mismatch repair gene germline mutations. Int J Colorectal Dis 2000; 15:255-63. [PMID: 11151427 DOI: 10.1007/s003840000261] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Hereditary nonpolyposis colorectal cancer (HNPCC), clinically defined by the Amsterdam criteria, is associated with mismatch repair gene germline mutations. This study was performed to evaluate the efficiency of combined clinical and molecular diagnostics in identifying carriers of a mutated gene in families meeting criteria of the Bethesda guidelines and to examine the influence of molecular diagnosis on clinical decision-making in carriers and noncarriers. Seventy-two patients meeting criteria of the Bethesda guidelines were tested for microsatellite instabilities (MSI). MSI-H tumors were found in 38 (52.8%) index patients. Complete sequencing of hMLH1 and hMSH2 in 38 MSI-H patients and of hMSH6 in one of these patients revealed 15 pathogenic germline mutations, including three novel mutations, and three novel unclassified germline variants. Twelve of the 15 pathogenic mutations were found in patients fulfilling the Amsterdam I/II criteria. Surgical and genetic counseling was offered to the affected families; as a result of molecular diagnosis in the 15 families, 26 index patients and affected carriers and 8 asymptomatic carriers of a mutated mismatch repair gene were included in the surveillance program, and 26 noncarriers were excluded from this program. Although germline mutations are detected in only 20.8% of patients fulfilling criteria of the Bethesda guidelines, family history and MSI-H tumor classification are both strong indicators for germline mutations in hMSH2, hMLH1, and hMSH6 genes, resulting in a 51.9% mutation detection rate. Identification of individual mutation status allows clear-cut decisions on whether or not inclusion in surveillance programs is indicated.
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Pistorius S, Schackert HK, Nagel M, Saeger HD. [Surgery of hereditary colorectal carcinoma]. Zentralbl Chir 2000; 125 Suppl 1:23-7. [PMID: 10929642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Hereditary colorectal cancer syndromes account for about 7% of all colorectal carcinomas. The most frequent form is Hereditary Nonpolyposis Colorectal Cancer (HNPCC). Identification, cloning and sequence analysis of the predisposing genes enables identification of mutation carriers and non-mutation carriers, respectively. These genetic informations can be used in an individually tailored clinical surveillance program and may ultimately result in standard preventive surgical treatment. In classical FAP the surgical standard is performing a restorative proctocolectomy. It is still unclear now, if this procedure should be modified in attenuated forms (colectomy with ileorectostomy). Due to a high rate of synchronous and metachronous carcinomas a subtotal colectomy in the case of first colon cancer seems to be indicated in HNPCC patients. A proctocolectomy or a restorative proctocolectomy should be weighed in case of carcinomas in the lower rectum. These procedures should be performed under the precondition of identification of the pathogenic germline mutation in the patient, only. In addition, a synchronous prophylactic hysterectomy with oophorectomy should be recommended postmenopausal gene carriers. Intensive counseling of the patient should proceed these preventive procedures involving surgeons, gastroenterologists, geneticists, molecular biologists, gynecologists, physicians and psychologists. It is recommended to have patients treated exclusively in specialized centers. Currently, six interdisciplinary centers for cancer surveillance and early diagnosis in hereditary colorectal cancer are being sponsored in Germany by the Deutsche Krebshilfe since 1999. In the future clinical studies have to be conducted to evaluate the efficacy of extended colorectal resections versus efficacy of surveillance and conventional resections according to general oncological principles.
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Hauses M, Schackert HK. [Gene therapy of malignant tumors]. Zentralbl Chir 2000; 125 Suppl 1:41-6. [PMID: 10929646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
New techniques in molecular biology and increasing insights in the genetic basis of tumorigenesis led to the development of therapeutic agents composed of genetic information. The majority of gene therapy trials is targeted towards cancer therapy. The most frequently used strategy is immunotherapy which comprises transfer of genes encoding cytokines, costimulatory molecules or tumorspecific antigens to enable cells of the immune system to identify and destroy tumor cells. The second important strategy makes use of suicide genes to selectively kill tumor cells. Compensation of genetic defects by the downregulation of activated oncogenes or the restoration of tumor suppressor gene functions is the third concept to revert the malignant phenotype of cancer cells.
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Sobottka SB, Haase M, Fitze G, Hahn M, Schackert HK, Schackert G. Frequent loss of heterozygosity at the 19p13.3 locus without LKB1/STK11 mutations in human carcinoma metastases to the brain. J Neurooncol 2000; 49:187-95. [PMID: 11212897 DOI: 10.1023/a:1006442024874] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Inactivating germline mutations of the novel putative tumor-suppressor gene LKB1/STK11 at 19p13.3 have been shown to cause Peutz-Jeghers syndrome (PJS), an autosomal dominantly inherited disease characterized by a predisposition to mucocutaneous pigmentations, as well as various benign and malignant neoplasms. To elucidate the role of LKB1/STK11 in the carcinogenesis of primary and secondary human brain tumors, a total of 309 tumors were analyzed for loss of heterozygosity (LOH) at microsatellite loci D19S886, DI9S878, and D19S565. Low LOH rates were observed for glioma (17.3%, n = 139), meningioma (5.3%, n = 57), schwannoma (0%, n = 21), pituitary adenoma (18.8%, n = 16), primary CNS lymphoma, neuroblastoma, plasmocytoma, medulloblastoma, germinoma, and papilloma of the choroid plexus (6.6%, n = 15). In contrast, brain metastases exhibited a mean LOH frequency of 42.6% (n = 61), with breast (56.3%) and lung cancer metastases (58.3%) being most frequently affected. Genomic DNA sequencing of the complete coding region of LKB1/STK11 was performed in all brain metastases exhibiting LOH (n = 26); no mutation was revealed, but we did find a germline mutation in a PJS patient. Despite high LOH fiequencies at the 19p13.3 locus in carcinoma metastases to the brain and occasional mutations reported for certain primary carcinomas, there are no mutations in LKB1/STK11. This fact suggests that alterations of LKB1/STK11 occur relatively early in tumorigenesis and are rarely involved in the development of carcinoma metastases. Based on these findings, the genes adjacent to LKB1/STK11 may be relevant for the development of metastases to the brain from certain carcinomas.
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34
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Plaschke J, Commer T, Jacobi C, Schackert HK, Chang-Claude J. BRCA2 germline mutations among early onset breast cancer patients unselected for family history of the disease. J Med Genet 2000; 37:E17. [PMID: 10978364 PMCID: PMC1734700 DOI: 10.1136/jmg.37.9.e17] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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35
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Schackert HK, Bornhäuser M, Dörr W, Frank S. [Biological principles for multimodal therapy approaches]. Zentralbl Chir 2000; 125:306-14. [PMID: 10829309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Cancer development and progression has been associated with numerous genetic events in tumor cells. Germline mutations of caretaker and gatekeeper genes are responsible for hereditary cancer syndromes. Exogenous factors in conjunction with functional germline variants of a variety of genes may contribute to tumor initiation in sporadic malignant disease. Furthermore, pathways to neoplasia require somatic events in the developing tumor. Acquired or inherited genetic instability permits stepwise tumor progression. The most fearsome aspect of tumor progression is dissemination of tumor cells to draining lymph nodes of the primary or to distant organs, which limits effectiveness of surgical therapy. Cellular heterogeneity of malignant neoplasms has important implications for chemotherapy and radiotherapy. An increasing understanding of the molecular biology of tumors is the prerequisite for improved prediction, prevention and therapy of malignant disease.
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Hampl M, Hampl JA, Schwarz P, Frank S, Hahn M, Schackert G, Saeger HD, Schackert HK. Accumulation of genetic alterations in brain metastases of sporadic breast carcinomas is associated with reduced survival after metastasis. INVASION & METASTASIS 2000; 18:81-95. [PMID: 10364688 DOI: 10.1159/000024501] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Tumor progression is characterized by stepwise accumulation of genetic alterations. To identify alterations associated with breast cancer metastasis, an analysis of comparative loss of heterozygosity (LOH) was performed on 38 primary sporadic breast carcinomas and 16 distant metastases. Two loci at 5q21 and 18q21 were chosen because of their reported increased deletion frequency in metastatic tumors. LOH at 17q21, 13q12-13, 17p13.1 and 11q22-23 was analyzed to determine whether there is a specific involvement of these breast cancer-associated gene loci in the metastatic process. Our data show that distant metastases are characterized by markedly increased LOH frequency at all loci examined. In both gene locus groups, significantly more distant metastases are affected by combined LOH. Furthermore, a significantly reduced postmetastatic survival time has been observed in patients with brain metastases affected by synchronous allelic loss at the four breast cancer-associated gene loci. Our results suggest that cumulative LOH of breast cancer-related gene loci is associated with a more aggressive phenotype of metastatic breast tumors.
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MESH Headings
- Ataxia Telangiectasia Mutated Proteins
- BRCA2 Protein
- Biomarkers, Tumor/genetics
- Brain Neoplasms/genetics
- Brain Neoplasms/mortality
- Brain Neoplasms/secondary
- Breast Neoplasms/genetics
- Breast Neoplasms/mortality
- Breast Neoplasms/pathology
- Carcinoma, Ductal, Breast/genetics
- Carcinoma, Ductal, Breast/mortality
- Carcinoma, Ductal, Breast/pathology
- Carcinoma, Ductal, Breast/secondary
- Cell Cycle Proteins
- Chromosomes, Human/genetics
- Chromosomes, Human/ultrastructure
- Chromosomes, Human, Pair 11/genetics
- Chromosomes, Human, Pair 13/genetics
- Chromosomes, Human, Pair 17/genetics
- DNA, Neoplasm/genetics
- DNA-Binding Proteins
- Female
- Genes, BRCA1
- Humans
- Life Tables
- Liver Neoplasms/genetics
- Liver Neoplasms/secondary
- Loss of Heterozygosity
- Lung Neoplasms/genetics
- Lung Neoplasms/secondary
- Microsatellite Repeats
- Mutation
- Neoplasm Invasiveness/genetics
- Neoplasm Metastasis
- Neoplasm Proteins/genetics
- Neoplasms, Multiple Primary/genetics
- Neoplasms, Multiple Primary/pathology
- Prognosis
- Protein Serine-Threonine Kinases/genetics
- Sequence Deletion
- Survival Analysis
- Transcription Factors/genetics
- Tumor Suppressor Proteins
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37
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Plaschke J, Kruppa C, Tischler R, Bocker T, Pistorius S, Dralle H, Rüschoff J, Saeger HD, Fishel R, Schackert HK. Sequence analysis of the mismatch repair gene hMSH6 in the germline of patients with familial and sporadic colorectal cancer. Int J Cancer 2000. [PMID: 10699937 DOI: 10.1002/(sici)1097-0215(20000301)85:5<606::aid-ijc2>3.0.co;2-b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
To evaluate the involvement of hMSH6 in colorectal cancer, the complete coding sequence and flanking intron regions of the gene were analyzed by DNA sequencing in 10 patients fulfilling Bethesda Guidelines for colorectal tumors and 10 patients with sporadic colorectal carcinoma. In addition, 10 mono- and 10 dinucleotide repeat markers were analyzed for microsatellite instability. A protein-truncating T insertion at codon 218 was identified in the index person of a hereditary non-polyposis colorectal cancer (HNPCC)-like kindred and was accompanied by a somatic T deletion in the tumor. The tumor of this patient was positive for mono- but negative for dinucleotide repeat instability and lacked allelic losses at loci frequently affected in colorectal carcinomas. A novel amino acid change, F340S, was found in a patient with sporadic colon and breast cancer and leukemia but was not detected in 246 chromosomes from healthy anonymous blood donors. In addition, we describe 2 silent and 15 intronic sequence variants not previously reported. Although the frequency is low, we present further evidence for hMSH6 germline mutations that predispose patients to HNPCC-like phenotypes and suggest that mono- and dinucleotide repeat instability testing may be useful for distinguishing between individuals harboring an hMSH2 or hMLH1 mutation and a mutation of the hMSH6 gene.
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38
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Plaschke J, Kruppa C, Tischler R, Bocker T, Pistorius S, Dralle H, Rüschoff J, Saeger HD, Fishel R, Schackert HK. Sequence analysis of the mismatch repair gene hMSH6 in the germline of patients with familial and sporadic colorectal cancer. Int J Cancer 2000; 85:606-13. [PMID: 10699937 DOI: 10.1002/(sici)1097-0215(20000301)85:5<606::aid-ijc2>3.0.co;2-b] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
To evaluate the involvement of hMSH6 in colorectal cancer, the complete coding sequence and flanking intron regions of the gene were analyzed by DNA sequencing in 10 patients fulfilling Bethesda Guidelines for colorectal tumors and 10 patients with sporadic colorectal carcinoma. In addition, 10 mono- and 10 dinucleotide repeat markers were analyzed for microsatellite instability. A protein-truncating T insertion at codon 218 was identified in the index person of a hereditary non-polyposis colorectal cancer (HNPCC)-like kindred and was accompanied by a somatic T deletion in the tumor. The tumor of this patient was positive for mono- but negative for dinucleotide repeat instability and lacked allelic losses at loci frequently affected in colorectal carcinomas. A novel amino acid change, F340S, was found in a patient with sporadic colon and breast cancer and leukemia but was not detected in 246 chromosomes from healthy anonymous blood donors. In addition, we describe 2 silent and 15 intronic sequence variants not previously reported. Although the frequency is low, we present further evidence for hMSH6 germline mutations that predispose patients to HNPCC-like phenotypes and suggest that mono- and dinucleotide repeat instability testing may be useful for distinguishing between individuals harboring an hMSH2 or hMLH1 mutation and a mutation of the hMSH6 gene.
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Gebert J, Sun M, Ridder R, Hinz U, Lehnert T, Möller P, Schackert HK, Herfarth C, von Knebel Doeberitz M. Molecular profiling of sporadic colorectal tumors by microsatellite analysis. Int J Oncol 2000. [PMID: 10601563 DOI: 10.3892/ijo.16.1.169] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To investigate the prognostic value of multiple genetic alterations, individual molecular tumor profiles were established in 79 sporadic colorectal carcinomas (41 stage II and 38 stage III). Tumors were analyzed for allelic loss (LOH) and genetic instability (MSI) using 14 microsatellites intragenic to or associated with tumor suppressor or DNA mismatch repair genes. Molecular profiling identified tumors with LOH at multiple loci without microsatellite instability (MSS), tumors with high levels of LOH and low level microsatellite marker instability (MSI-L), and tumors with high levels of MSI (MSI-H), but rare LOH. K-ras mutations occurred more frequently in MSS/MSI-L carcinomas (26%) than in MSI-H colorectal tumors (10%), the latter showing a high frequency of TGFbeta type II frameshift mutations (82%). Correlation of molecular and clinical data revealed a better prognosis for stage III tumor patients displaying 5q12 loss rather than retention of heterozygosity. Thus, molecular profiling allows the identification of new prognostic markers and might facilitate the stratification of colorectal cancer patients.
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40
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Gebert J, Sun M, Ridder R, Hinz U, Lehnert T, Möller P, Schackert HK, Herfarth C, von Knebel Doeberitz M. Molecular profiling of sporadic colorectal tumors by microsatellite analysis. Int J Oncol 2000; 16:169-79. [PMID: 10601563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
To investigate the prognostic value of multiple genetic alterations, individual molecular tumor profiles were established in 79 sporadic colorectal carcinomas (41 stage II and 38 stage III). Tumors were analyzed for allelic loss (LOH) and genetic instability (MSI) using 14 microsatellites intragenic to or associated with tumor suppressor or DNA mismatch repair genes. Molecular profiling identified tumors with LOH at multiple loci without microsatellite instability (MSS), tumors with high levels of LOH and low level microsatellite marker instability (MSI-L), and tumors with high levels of MSI (MSI-H), but rare LOH. K-ras mutations occurred more frequently in MSS/MSI-L carcinomas (26%) than in MSI-H colorectal tumors (10%), the latter showing a high frequency of TGFbeta type II frameshift mutations (82%). Correlation of molecular and clinical data revealed a better prognosis for stage III tumor patients displaying 5q12 loss rather than retention of heterozygosity. Thus, molecular profiling allows the identification of new prognostic markers and might facilitate the stratification of colorectal cancer patients.
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41
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Saeger HD, Nagel M, Schackert HK. [Hierarchy and research]. Zentralbl Chir 1999; 124 Suppl 3:33-4. [PMID: 10596069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Surgical research needs structural and organizational conditions. These have to ensure, that the young surgeon finds the opportunity for scientific activities and development in a highly professional environment.
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Hahn M, Saeger HD, Schackert HK. Hereditary colorectal cancer: clinical consequences of predictive molecular testing. Int J Colorectal Dis 1999; 14:184-93. [PMID: 10647626 DOI: 10.1007/s003840050210] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The continuing increase in knowledge about the genetic basis of carcinogenesis has led to diverse efforts to exploit this knowledge clinically, primarily in the form of predictive genetic testing. In conjunction with family history, gene tests are intended to improve individual cancer risk assessment. The objectives of predictive molecular testing are to identify the disease-causing germline mutation in an index person who has already developed the disease and to distinguish asymptomatic mutation carriers from non-mutation carriers within a given cancer-prone family. At present, genetic testing for colorectal cancer risk, primarily in form of DNA sequencing, is applied in familial adenomatous polyposis (FAP) and hereditary nonpolyposis colorectal cancer (HNPCC). In these inherited colorectal tumor syndromes determining the genetic status may result in an individually tailored surveillance program and prophylactic treatment. The implications of genetic testing for the clinical management of disease, both of mutation and non-mutation carriers, in familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer families are discussed.
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Hauses M, Schackert HK. Gene therapy and gastrointestinal cancer: concepts and clinical facts. Langenbecks Arch Surg 1999; 384:479-88. [PMID: 10552295 DOI: 10.1007/s004230050234] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Principles of the treatment of gastrointestinal cancer with gene therapy evolved from the advent of techniques in molecular biology, from increasing insights into the molecular basis of tumorigenesis and from the need to develop more efficient treatment modalities. Any gene therapy approach has to take two major tasks into consideration: the therapeutic gene has to be delivered into the target cell population with high efficiency, specificity and safety, and has to act in a way that provides a benefit to the patient. DISCUSSION Data on 22 clinical trials on malignancies of the gastrointestinal tract are available. They utilize a variety of gene-delivery methods and target cell populations, and there is considerable variety among their strategies. Gene transfer is performed by injection of naked plasmid DNA and by use of DNA-liposome complexes and viral vectors. In some cases, the gene transfer is carried out ex vivo and the patients receive genetically modified cells, whereas other approaches deliver the vector to the target cell population in vivo. The theoretical concepts of gene therapy can be divided into three groups. One approach makes use of suicide genes comprising bacterial or viral genes that convert a nontoxic prodrug into a highly cytotoxic chemotherapeutic agent at the tumor site. This approach aims at higher therapeutic specificity and fewer side effects than with the systemic delivery of cytotoxic agents. The second strategy makes an attempt to invoke the immune system to destroy malignant cells. Different strategies, such as immunization with genetically modified tumor cells or transfer of new genes to T cells, are considered to have clinical benefits. The major advantage of these immunotherapeutic approaches is the systemic effect both on the primary tumor and on metastases. The third strategy evolved from the insight that cancer is a genetic disease caused by activation of oncogenes or inactivation of tumor-suppressor genes. Compensation of genetic defects by the downregulation of activated oncogenes or the restoration of tumor-suppressor-gene functions may be able to revert the malignant phenotype of cancer cells. Of the 22 gene-therapy trials, 17 trials focus on immunotherapy. Only two trials make use of suicide genes and, in three trials, a functional copy of the p53 tumor-suppressor gene was reintroduced into malignant cells. Modalities for gene transfer and the strategies underlying gene therapy will be discussed in the context of gastrointestinal malignancies and the potential benefits for patients.
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44
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Plaschke J, Bulitta C, Saeger HD, Schackert HK. Quantitative differences between aberrant transcripts which occur as common isoforms and due to mutation-based exon skipping of the mismatch repair gene hMLH1. Clin Chem Lab Med 1999; 37:883-7. [PMID: 10596954 DOI: 10.1515/cclm.1999.131] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
About one-third of hereditary non-polyposis colorectal cancer-related mutations in the mismatch repair gene hMLH1 result in the loss of entire exons from the wild type transcripts. Here we describe quantitative differences of hMLH1 transcripts without exon 15, exon 16 or exon 17 in several members of a family with hereditary non-polyposis colorectal cancer. The transcript lacking exon 15 is caused by a G to A transition affecting the last nucleotide of the respective exon and results in a truncated protein. The transcripts lacking exon 16 or exon 17, which are in-frame deletions, were also found in all tested samples of a normal population and represent common isoforms. Reverse transcription-polymerase chain reaction-based relative quantification revealed about 50 % signal intensity for the mutation-based transcript, but less than 10% for the common isoforms, if compared to the wild type. All aberrant transcripts were detected from blood-derived cDNAs but not from samples of normal colon epithelium. Although the biological significance of the common isoforms is unknown, they might lead to false risk assessment in hereditary non-polyposis colorectal cancer cases.
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Hahn M, Wieland I, Koufaki ON, Görgens H, Sobottka SB, Schackert G, Schackert HK. Genetic alterations of the tumor suppressor gene PTEN/MMAC1 in human brain metastases. Clin Cancer Res 1999; 5:2431-7. [PMID: 10499615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
The high mutation rate in advanced brain tumors, recent functional studies, and the high frequency of mutations in prostate metastases all strongly suggest that PTEN/MMAC1 alterations are involved in the formation of metastases. We searched for genetic alterations in the PTEN/MMAC1 gene in 56 consecutive brain metastases from various primary tumors by loss of heterozygosity (LOH), direct sequence analysis, and differential PCR analysis. The highest LOH rates were detected in metastases deriving from lung (67%) and breast (64%) cancers. Three (25%) of the eight detected inactivating mutations (one nonsense mutation, one splice-site mutation, one 11-bp deletion, and five homozygous deletions) were found in metastases originating from 12 different lung carcinomas, suggesting that PTEN/MMAC1 alterations may play a role in the progression of this tumor. With the exception of lung carcinomas, our findings indicate that genetic abnormalities of the PTENM/MMAC1 gene are only involved in a relatively small subset of brain metastases. However, the discrepancy between the high overall LOH rate (50%) and the low frequency of PTEN/MMAC1 mutation detection rate (14%) suggests the presence of one or more additional tumor suppressor genes on chromosome 10q.
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Hahn M, Kruppa C, Pistorius S, Schackert HK. [Predictive molecular diagnosis and preventive surgical treatment of hereditary colorectal carcinoma: a new field of interest for surgical research]. Zentralbl Chir 1999; 124:278-85. [PMID: 10355081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Colorectal cancer is one of the most frequent cancers in the Western hemisphere. It seems to be well established that colorectal tumors develop as a result of an accumulation of inherited and/or acquired somatic mutational events in tumor suppressor genes and oncogenes. An increasing understanding of the molecular basis of the most prevalent colorectal cancer syndromes, such as hereditary nonpolyposis colorectal cancer (HNPCC) and familial adenomatous polyposis (FAP), is reflected by modifications in diagnosis and therapy. Therefore, strategies have been developed for predictive molecular diagnosis and preventive surgical treatment of colorectal cancer syndromes. In the future surgical research will participate in research and development in the field of molecular diagnosis of colorectal cancer and will then evaluate the clinical management concepts as a result.
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Hampl M, Hampl JA, Reiss G, Schackert G, Saeger HD, Schackert HK. Loss of heterozygosity accumulation in primary breast carcinomas and additionally in corresponding distant metastases is associated with poor outcome. Clin Cancer Res 1999; 5:1417-25. [PMID: 10389927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
The occurrence of distant metastases is the most feared manifestation of breast cancer, often occurring years after the primary surgery and associated with poor survival. The dominant metastatic clone is characterized by an accumulation of genetic alterations, but it is not actually known at what stage of the metastatic cascade these alterations have occurred. We investigated allelic losses during breast cancer progression in a series of 17 primary breast carcinomas and 22 corresponding brain, liver, lung, and bone metastases (mean metastasis-free interval, 31 months) by analyzing 19 microsatellite markers on seven breast cancer- or metastasis-related chromosomal regions and correlated the incidence of combined loss of heterozygosity (LOH) with metastasis-free and postmetastatic survival. We found that, in comparison with the corresponding primary tumor, additional LOH events are frequently found in metastases and that the incidence of combined LOH in the primary tumor, plus the occurrence of additional LOH events in the distant metastases, correlated significantly with decreased postmetastatic survival. Combined LOH of the three breast cancer-related chromosomal regions alone or in combination with allelic loss at the p53 gene region seems to have a specific influence on the aggressive behavior of metastases. We hypothesize that the occurrence of additional LOH events is either involved in termination of dormancy of micrometastatic tumor cells at distant organ sites or acquired during further progression of metastases.
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Frank S, Köhler U, Schackert G, Schackert HK. Expression of TRAIL and its receptors in human brain tumors. Biochem Biophys Res Commun 1999; 257:454-9. [PMID: 10198234 DOI: 10.1006/bbrc.1999.0493] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Recently, TRAIL has been demonstrated to selectively induce apoptosis in transformed cell lines, and subsequently four receptors (TRAIL-R1-TRAIL-R4) have been identified. The ability to transduce death signals is restricted to TRAIL-R1/TRAIL-R2. In contrast, TRAIL-R3/TRAIL-R4 are unable to activate apoptotic pathways and have therefore been suggested to act as "decoys" protecting normal tissues from cell death. However, the biological role of the TRAIL system remains incompletely understood. We analyzed the expression of TRAIL and its receptors in a panel of human brain tumors (n = 34) and in four glioma cell lines in comparison to normal brain tissue. Constant co-expression of TRAIL and of receptors TRAIL-R1, TRAIL-R2, and TRAIL-R3 in different tumor entities as well as in normal brain indicates that additional mechanisms might modulate the previously proposed "decoy" model. Furthermore, in contrast to previous reports, we demonstrate TRAIL and TRAIL-R2 to be present on a transcriptional level in normal brain tissue. Exceptional expression of TRAIL-R4 transcripts does not suggest a significant regulatory role of this receptor in the human brain and its tumors.
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Schackert HK, Hahn M, Pistorius S, Saeger HD. [Preventive surgery of inherited colorectal cancer identified through molecular diagnosis]. Chirurg 1999; 70:345-52. [PMID: 10354829 DOI: 10.1007/s001040050656] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Numerous inherited genetic changes predisposing to cancer have already been identified and the number is increasing. Accurate prediction of individual risk by means of molecular diagnosis implies clinical consequences in the treatment of cancer-predisposing syndromes. Using familial adenomatous polyposis (FAP) and hereditary non-polyposis colorectal cancer (HNPCC) as an example, we present here the underlying genetic changes that contribute to tumor development. These genetic alterations can be efficiently identified through molecular diagnostic techniques. Identification of the familial germline mutation permits one to distinguish mutation carriers from non-mutation carriers within affected families and results in individually tailored surveillance and prevention. Therefore, molecular diagnosis is making a contribution to the advances in preventive surgical therapy. The indications are discussed.
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Gebert JF, Dupon C, Kadmon M, Hahn M, Herfarth C, von Knebel Doeberitz M, Schackert HK. Combined molecular and clinical approaches for the identification of families with familial adenomatous polyposis coli. Ann Surg 1999; 229:350-61. [PMID: 10077047 PMCID: PMC1191700 DOI: 10.1097/00000658-199903000-00008] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Using an interdisciplinary clinical and molecular approach, the authors identified APC germline mutations in families with familial adenomatous polyposis (FAP). Correlation of mutation site with disease manifestation and the impact of molecular data on clinical proceedings were examined. SUMMARY BACKGROUND DATA Germline mutations in the APC gene predispose to FAP. Established and proposed genotype-phenotype correlations as well as the influence of mutation site on surgical procedures have been reported. The predictive value of APC mutation analysis for disease manifestation and therapeutic decision making needs to be investigated further. METHODS One hundred twenty-three kindreds of the local FAP registry were included in this study. CHRPE phenotype was defined as at least one large characteristic lesion or a total of four lesions in both eyes. APC mutations were identified by protein truncation test and automated DNA sequencing from patient lymphocyte DNA and RNA. RESULTS APC germline mutations were identified in 85/123 families with FAP. They were located between codons 213 and 1581 of the APC gene and displayed distinct genotype-phenotype correlations. CHRPE status facilitated mutation analysis by discriminating regions of interest within the APC coding region. Severe manifestations of desmoids were restricted to mutations between codons 1444 through 1581. Whereas 91% (75/82) of at-risk persons were excluded as mutation carriers, APC germline mutations were detected before clinical examination in 9% (7/82) of at-risk persons. One patient agreed to endoscopy only after mutation detection. CONCLUSIONS This study supports the feasibility of combined molecular and clinical screening of families with FAP and may provide a guideline for routine presymptomatic molecular diagnostics in a clinical laboratory.
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