Jochen B Geigl

Publications of Jochen B Geigl

• High-resolution analyses of copy number changes in disseminated tumor cells of patients with breast cancer.

  Authors: Randi R Mathiesen, Renathe Fjelldal, Knut Liestøl, Eldri U Due, Jochen B Geigl, Sabine Riethdorf, Elin Borgen, Inga H Rye, Ida J Schneider, Anna C Obenauf, Oliver Mauermann, Gro Nilsen, Ole Christian Lingjaerde, Anne-Lise Børresen-Dale, Klaus Pantel, Michael R Speicher, Bjørn Naume, Lars O Baumbusch

  International journal of cancer. Journal international du cancer. 09/2011;

  The presence of disseminated tumor cells (DTCs) in bone marrow (BM) identifies breast cancer patients with less favorable outcome. Furthermore, molecular characterization is required to investigateThe presence of disseminated tumor cells (DTCs) in bone marrow (BM) identifies breast cancer patients with less favorable outcome. Furthermore, molecular characterization is required to investigate the malignant potential of these cells. This study presents a single-cell array comparative genomic hybridization (SCaCGH) method providing molecular analysis of immunomorphologically detected DTCs. The resolution limit of the method was estimated using the cancer cell line SK-BR-3 on 44 and 244k arrays. The technique was further tested on 28 circulating tumor cells and four hematopoietic cells (HCs) from peripheral blood (n = 8 patients). The SCaCGH method was finally applied to 24 DTCs, three immunopositive cells morphologically classified as probable HCs from breast cancer patients and five HC controls from BM (n = 7 patients plus n = 1 healthy donor). The frequency of copy number changes of the DTCs revealed similarities with primary breast tumor samples. Three of the patients had available profiles for DTCs and the corresponding tumor tissue from primary surgery. More than two-third of the analyzed DTCs disclosed equivalent changes, both to each other and to the corresponding primary disease, whereas the rest of the cells showed balanced profiles. The probable HCs revealed either balanced profiles (n = 2) or changes comparable to the tumor tissue and DTCs (n = 1), indicating morphological overlap between HCs and DTCs. Similar aberration patterns were visible in DTCs collected at diagnosis and at 3 years relapse-free follow-up. SCaCGH may be a powerful tool for the molecular characterization of DTCs.

• Multiple intratumoral KRAS mutations can clonally segregate to different lymph node metastases in colon cancer.

  Authors: Stephan W Jahn, Gerlinde Winter, Elvira Stacher, Iris Halbwedl, Stefan Gattenlöhner, Richard Stockinger, Stefan Spreitzer, Julie Waldispuehl-Geigl, Jochen B Geigl, Felix Offner, Gerald Hoefler

  Histopathology. 08/2011; 59(2):342-5.

• Combined molecular genetic and cytogenetic analysis from single cells after isothermal whole-genome amplification.

  Authors: Thomas Kroneis, Jochen B Geigl, Amin El-Heliebi, Martina Auer, Peter Ulz, Thomas Schwarzbraun, Gottfried Dohr, Peter Sedlmayr

  Clinical chemistry. 05/2011; 57(7):1032-41.

  Analysis of chromosomal aberrations or single-gene disorders from rare fetal cells circulating in the blood of pregnant women requires verification of the cells' genomic identity. We have developed aAnalysis of chromosomal aberrations or single-gene disorders from rare fetal cells circulating in the blood of pregnant women requires verification of the cells' genomic identity. We have developed a method enabling multiple analyses at the single-cell level that combines verification of the genomic identity of microchimeric cells with molecular genetic and cytogenetic diagnosis. We used a model system of peripheral blood mononuclear cells spiked with a colon adenocarcinoma cell line and immunofluorescence staining for cytokeratin in combination with DNA staining with the nuclear dye TO-PRO-3 in a preliminary study to define candidate microchimeric (tumor) cells in Cytospin preparations. After laser microdissection, we performed low-volume on-chip isothermal whole-genome amplification (iWGA) of single and pooled cells. DNA fingerprint analysis of iWGA aliquots permitted successful identification of all analyzed candidate microchimeric cell preparations (6 samples of pooled cells, 7 samples of single cells). Sequencing of 3 single-nucleotide polymorphisms was successful at the single-cell level for 20 of 32 allelic loci. Metaphase comparative genomic hybridization (mCGH) with iWGA products of single cells showed the gains and losses known to be present in the genomic DNA of the target cells. This method may be instrumental in cell-based noninvasive prenatal diagnosis. Furthermore, the possibility to perform mCGH with amplified DNA from single cells offers a perspective for the analysis of nonmicrochimeric rare cells exhibiting genomic alterations, such as circulating tumor cells.

• Evolution of genomic instability in diethylnitrosamine-induced hepatocarcinogenesis in mice.

  Authors: Kristina Aleksic, Carolin Lackner, Jochen B Geigl, Martina Schwarz, Martina Auer, Peter Ulz, Maria Fischer, Zlatko Trajanoski, Marcus Otte, Michael R Speicher

  Hepatology (Baltimore, Md.). 03/2011; 53(3):895-904.

  Diethylnitrosamine (DEN) is a hepatic procarcinogen which is frequently used as an inducer of hepatocellular carcinoma (HCC) in mice. Although mice after DEN exposure are among the most widely usedDiethylnitrosamine (DEN) is a hepatic procarcinogen which is frequently used as an inducer of hepatocellular carcinoma (HCC) in mice. Although mice after DEN exposure are among the most widely used models for liver tumorigenesis, a detailed, mechanistic characterization of the longitudinal changes in the respective tumor genomes has never been performed. Here we established the chronological order of genetic alterations during DEN carcinogenesis by examining mice at different points in time. Tumor samples were isolated by laser microdissection and subjected to array-comparative genomic hybridization (array-CGH) and sequencing analysis. Chromosomal gains and losses were observed in tumors by week 32 and increased significantly by week 56. Loss of distal chromosome 4q, including the tumor suppressors Runx3 and Nr0b2/Shp, was a frequent early event and persisted during all tumor stages. Surprisingly, sequencing revealed that β-catenin mutations occurred late and were clearly preceded by chromosomal instability. Thus, contrary to common belief, β-catenin mutations and activation of the Wnt/β-catenin pathway are not involved in tumor initiation in this model of chemical hepatocarcinogenesis. CONCLUSION: Our study suggests that the majority of the current knowledge about genomic changes in HCC is based on advanced tumor lesions and that systematic analyses of the chronologic order including early lesions may reveal new, unexpected findings.

• Androgen receptor expression in breast cancer patients tested for BRCA1 and BRCA2 mutations.

  Authors: Gunda Pristauz, Edgar Petru, Elvira Stacher, Jochen B Geigl, Thomas Schwarzbraun, Oleksiy Tsybrovskyy, Raimund Winter, Farid Moinfar

  Histopathology. 12/2010; 57(6):877-84.

  To assess the expression of receptors for androgen (AR), oestrogen (ER) and progesterone (PR) as well as human epidermal growth factor receptor type 2 (Her-2/neu) status of breast carcinomas inTo assess the expression of receptors for androgen (AR), oestrogen (ER) and progesterone (PR) as well as human epidermal growth factor receptor type 2 (Her-2/neu) status of breast carcinomas in breast cancer susceptibility gene (BRCA) BRCA1/2 mutation carriers and BRCA1/2 negative tested women. One hundred and thirty-five breast cancers in women tested for BRCA1/2 mutations. Screening for BRCA1 and BRCA2 mutations was performed by direct sequencing of all BRCA1 and BRCA2 exons as well as the surrounding intronic sequences. Additionally, BRCA genes were analysed with multiplex ligation-dependent probe amplification. Consecutive paraffin sections were examined immunohistochemically for AR, ER, PR and Her-2/neu. Of the 135 tumours, 43 (32%) were BRCA1-related, 18 (13%) were BRCA2-related and 74 (55%) were BRCA1/2-negative. Seventy-two per cent of the BRCA1-related, 22% of the BRCA2-related and 12% of the BRCA1/2-negative tumours were triple (ER, PR, Her2neu)-negative. Eighty-four per cent of BRCA1 mutated cancers were high-grade (G3) tumours. ARs were expressed in 30% (13 of 43) of BRCA1-related, in 78% (14 of 18) in BRCA2-related tumours and in 76% (56 of 74) in BRCA1/2 negative tumours. Twenty-one per cent of ER-negative BRCA1-related tumours expressed androgen receptors. Approximately one in five BRCA1 mutated breast cancers negative for ER and PR express androgen receptors. Modulation of AR might open a new avenue for treating these high-risk cancers.

• [Genes beyond BRCA1 and BRCA2 for hereditary breast cancer].

  Authors: Katharina Simon, Jochen B Geigl, Gunda Pristauz

  Wiener medizinische Wochenschrift (1946). 10/2010; 160(19-20):478-82.

  germline mutations in the tumor suppressor genes BRCA1 and BRCA2 are identified in less than 50% of hereditary breast cancer cases. Besides BRCA1/2 further high-risk breast cancer genes are known;germline mutations in the tumor suppressor genes BRCA1 and BRCA2 are identified in less than 50% of hereditary breast cancer cases. Besides BRCA1/2 further high-risk breast cancer genes are known; however they account only for a small fraction of inherited breast cancer cases. Most of them are involved in rare cancer predisposition syndromes. Moderate and low-risk breast cancer genes confer modest cancer risk up to 10% and may be more relevant due to polygenic inheritance. The majority of hereditary breast cancer cases are still caused by unknown genes. genetic testing of other known genes is not yet routinely performed in families tested negative for BRCA1/2-mutations, but can be recommended in special patients. In case of a calculated high-risk situation, participation in an early-detection screening program should be recommended. genetic susceptibility to breast cancer is heterogeneous and conferred by a large number of identified and yet undetected genes.

• Effect of genome-wide association studies, direct-to-consumer genetic testing, and high-speed sequencing technologies on predictive genetic counselling for cancer risk.

  Authors: Michael R Speicher, Jochen B Geigl, Ian P Tomlinson

  The lancet oncology. 09/2010; 11(9):890-8.

  Genetic counselling is offered to patients with various hereditary cancers. At-risk family members can be identified by predictive testing and included in specifically designed screening andGenetic counselling is offered to patients with various hereditary cancers. At-risk family members can be identified by predictive testing and included in specifically designed screening and prevention programmes. Since genetic testing has far-reaching ethical and medical outcomes, it is usually done according to well-defined guidelines developed by medical societies, entailing extensive interaction between family members and medical health providers. This established procedure is now changing after three new developments. First, data from genome-wide association studies have identified many new loci in the human genome, which could moderately change cancer risk. Second, although inclusion of low-risk cancer genes in patients' risk assessments represents an unresolved challenge, several companies already offer such tests in a direct-to-consumer format over the internet. These tests shift control of genetic testing from medical professionals to individuals. Third, development of high-speed sequencing technologies multiplies available genomic data and enables rapid sequencing of entire human genomes at low costs. This innovation will pave the way for personalised genetics and new options for predictive testing. Here, we use the example of genetic counselling in colon cancer to describe how these developments will change genetic testing in families at risk of cancer and in the general population.

• Mapping of balanced chromosome translocation breakpoints to the basepair level from microdissected chromosomes.

  Authors: Anna C Obenauf, Thomas Schwarzbraun, Martina Auer, Eva M Hoffmann, Julie Waldispuehl-Geigl, Peter Ulz, Barbara Günther, Hans-Christoph Duba, Michael R Speicher, Jochen B Geigl

  Journal of cellular and molecular medicine. 08/2010; 14(8):2078-84.

  The analysis of structural variants associated with specific phenotypic features is promising for the elucidation of the function of involved genes. There is, however, at present no approach allowingThe analysis of structural variants associated with specific phenotypic features is promising for the elucidation of the function of involved genes. There is, however, at present no approach allowing the rapid mapping of chromosomal translocation breakpoints to the basepair level from a single chromosome. Here we demonstrate that we have advanced both the microdissection and the subsequent unbiased amplification to an extent that breakpoint mapping to the basepair level has become possible. As a case in point we analysed the two breakpoints of a t(7;13) translocation observed in a patient with split hand/foot malformation (SHFM1). The amplification products of the der(7) and of the der(13) were hybridized to custom-made arrays, enabling us to define primers at flanking breakpoint regions and thus to fine-map the breakpoints to the basepair level. Consequently, our results will also contribute to a further delineation of causative mechanisms underlying SHFM1 which are currently unknown.

• [BRCA1- and BRCA2 mutations: Clinical management of patients with hereditary breast and ovarian cancer].

  Authors: Gunda Pristauz, Jochen B Geigl, Edgar Petru

  Wiener medizinische Wochenschrift (1946). 04/2010; 160(7-8):158-62.

  BACKGROUND: In total, 5-10% of all breast cancer cases are related to gen mutations. In most cases a mutation in the BRCA1-gen and BRCA2-gen is responsible for insufficient repair of DNA damages thatBACKGROUND: In total, 5-10% of all breast cancer cases are related to gen mutations. In most cases a mutation in the BRCA1-gen and BRCA2-gen is responsible for insufficient repair of DNA damages that cause breast and ovarian cancer. CLINICAL MANAGEMENT: In patients carrying BRCA1-mutation the risk for developing breast and ovarian cancer is 87% and 40% as well as 47% and 20% for those carrying a BRCA2-mutation. Women at hereditary risk should be informed about existing recommendations for surveillance. Primary prevention of breast and ovarian cancer including prophylactic surgery (bilateral salpingoophorectomy and bilateral mastectomy) should be explained to mutation carriers. The issue of oral antihormonal therapy for prevention of breast cancer should be addressed. Psycho-social support should be offered to mutation carriers. CONCLUSIONS: The clinical management of BRCA1 and BRCA2-mutation carriers is very challenging and should be done in centres specialized in this issue.

• Sporadic gastric Peutz-Jeghers polyp with intraepithelial neoplasia.

  Authors: Lars Harbaum, Jochen B Geigl, Hildegard Volkholz, Thomas Schwarzbraun, Harald Oschmautz, Michael Vieth, Cord Langner

  APMIS : acta pathologica, microbiologica, et immunologica Scandinavica. 12/2009; 117(12):941-3.

• Identification of small gains and losses in single cells after whole genome amplification on tiling oligo arrays.

  Authors: Jochen B Geigl, Anna C Obenauf, Julie Waldispuehl-Geigl, Eva M Hoffmann, Martina Auer, Martina Hörmann, Maria Fischer, Zlatko Trajanoski, Michael A Schenk, Lars O Baumbusch, Michael R Speicher

  Nucleic acids research. 07/2009;

  Clinical DNA is often available in limited quantities requiring whole-genome amplification for subsequent genome-wide assessment of copy-number variation (CNV) by array-CGH. In pre-implantationClinical DNA is often available in limited quantities requiring whole-genome amplification for subsequent genome-wide assessment of copy-number variation (CNV) by array-CGH. In pre-implantation diagnosis and analysis of micrometastases, even merely single cells are available for analysis. However, procedures allowing high-resolution analyses of CNVs from single cells well below resolution limits of conventional cytogenetics are lacking. Here, we applied amplification products of single cells and of cell pools (5 or 10 cells) from patients with developmental delay, cancer cell lines and polar bodies to various oligo tiling array platforms with a median probe spacing as high as 65 bp. Our high-resolution analyses reveal that the low amounts of template DNA do not result in a completely unbiased whole genome amplification but that stochastic amplification artifacts, which become more obvious on array platforms with tiling path resolution, cause significant noise. We implemented a new evaluation algorithm specifically for the identification of small gains and losses in such very noisy ratio profiles. Our data suggest that when assessed with sufficiently sensitive methods high-resolution oligo-arrays allow a reliable identification of CNVs as small as 500 kb in cell pools (5 or 10 cells), and of 2.6-3.0 Mb in single cells.

• 9p21 Deletion in Primary Cutaneous Large B-Cell Lymphoma, Leg Type, May Escape Detection by Standard FISH Assays.

  Authors: Thomas Wiesner, Anna C Obenauf, Jochen B Geigl, Eva-Maria Vallant, Michael R Speicher, Regina Fink-Puches, Helmut Kerl, Lorenzo Cerroni

  The Journal of investigative dermatology. 09/2008;

• Defining 'chromosomal instability'.

  Authors: Jochen B Geigl, Anna C Obenauf, Thomas Schwarzbraun, Michael R Speicher

  Trends in genetics : TIG. 03/2008; 24(2):64-9.

  Most scientists agree that the majority of human solid malignant tumors are characterized by chromosomal instability (CIN) involving gain or loss of whole chromosomes or fractions of chromosomes. CINMost scientists agree that the majority of human solid malignant tumors are characterized by chromosomal instability (CIN) involving gain or loss of whole chromosomes or fractions of chromosomes. CIN is thought to be an early event during tumorigenesis and might therefore be involved in tumor initiation. Despite its frequent occurrence in tumors and its potential importance in tumor evolution, CIN is poorly defined and is used inconsistently and imprecisely. Here, we provide criteria to define CIN and argue that few experimental approaches are capable of assessing the presence of CIN. Accurate assessment of CIN is crucial to elucidate whether CIN is a driving force for tumorigenesis and whether a chromosomally unstable genome is necessary for tumor progression.

• Systemic spread is an early step in breast cancer.

  Authors: Yves Hüsemann, Jochen B Geigl, Falk Schubert, Piero Musiani, Manfred Meyer, Elke Burghart, Guido Forni, Roland Eils, Tanja Fehm, Gert Riethmüller, Christoph A Klein

  Cancer cell. 02/2008; 13(1):58-68.

  It is widely accepted that metastasis is a late event in cancer progression. Here, however, we show that tumor cells can disseminate systemically from earliest epithelial alterations in HER-2 andIt is widely accepted that metastasis is a late event in cancer progression. Here, however, we show that tumor cells can disseminate systemically from earliest epithelial alterations in HER-2 and PyMT transgenic mice and from ductal carcinoma in situ in women. Wild-type mice transplanted with single premalignant HER-2 transgenic glands displayed disseminated tumor cells and micrometastasis in bone marrow and lungs. The number of disseminated cancer cells and their karyotypic abnormalities were similar for small and large tumors in patients and mouse models. When activated by bone marrow transplantation into wild-type recipients, 80 early-disseminated cancer cells sufficed to induce lethal carcinosis. Therefore, release from dormancy of early-disseminated cancer cells may frequently account for metachronous metastasis.

• High resolution array-CGH analysis of single cells.

  Authors: Heike Fiegler, Jochen B Geigl, Sabine Langer, Diane Rigler, Keith Porter, Kristian Unger, Nigel P Carter, Michael R Speicher

  Nucleic acids research. 02/2007; 35(3):e15.

  Heterogeneity in the genome copy number of tissues is of particular importance in solid tumor biology. Furthermore, many clinical applications such as pre-implantation and non-invasive prenatalHeterogeneity in the genome copy number of tissues is of particular importance in solid tumor biology. Furthermore, many clinical applications such as pre-implantation and non-invasive prenatal diagnosis would benefit from the ability to characterize individual single cells. As the amount of DNA from single cells is so small, several PCR protocols have been developed in an attempt to achieve unbiased amplification. Many of these approaches are suitable for subsequent cytogenetic analyses using conventional methodologies such as comparative genomic hybridization (CGH) to metaphase spreads. However, attempts to harness array-CGH for single-cell analysis to provide improved resolution have been disappointing. Here we describe a strategy that combines single-cell amplification using GenomePlex library technology (GenomePlex) Single Cell Whole Genome Amplification Kit, Sigma-Aldrich, UK) and detailed analysis of genomic copy number changes by high-resolution array-CGH. We show that single copy changes as small as 8.3 Mb in single cells are detected reliably with single cells derived from various tumor cell lines as well as patients presenting with trisomy 21 and Prader-Willi syndrome. Our results demonstrate the potential of this technology for studies of tumor biology and for clinical diagnostics.

• [Genetic counseling in multiple pregnancies]

  Authors: Sabine Uhrig, Jochen B Geigl, Michael R Speicher

  Gynäkologisch-geburtshilfliche Rundschau. 02/2007; 47(1):9-13.

  Genetic counseling in cases of multiple pregnancies shows marked differences compared to singleton pregnancies. The rising rate of multiple pregnancies and its association with advanced maternal ageGenetic counseling in cases of multiple pregnancies shows marked differences compared to singleton pregnancies. The rising rate of multiple pregnancies and its association with advanced maternal age has expanded the need for prenatal diagnosis in twins and higher-order gestations. However, the request for invasive prenatal diagnostic procedures often differs in multiple and singleton pregnancies. This is in particular true when the multiple pregnancy occurred after assisted reproductive technology. In case of twin pregnancies, the distinction between a mono- and dizygotic pregnancy may facilitate the decision about obtaining a single or two samples. Discordant anomalies pose a special problem. Discordant anomalies are in rare instances even observed in monozygotic pregnancies. Here, we summarize the clinical, analysis-related and ethical problems regarding genetic counseling in multiple pregnancies.

• Single-cell isolation from cell suspensions and whole genome amplification from single cells to provide templates for CGH analysis.

  Authors: Jochen B Geigl, Michael R Speicher

  Nature protocols. 02/2007; 2(12):3173-84.

  A comprehensive genomic analysis of single cells is instrumental for numerous applications in tumor genetics, clinical diagnostics and forensic analyses. Here, we provide a protocol for single-cellA comprehensive genomic analysis of single cells is instrumental for numerous applications in tumor genetics, clinical diagnostics and forensic analyses. Here, we provide a protocol for single-cell isolation and whole genome amplification, which includes the following stages: preparation of single-cell suspensions from blood or bone marrow samples and cancer cell lines; their characterization on the basis of morphology, interphase fluorescent in situ hybridization pattern and antibody staining; isolation of single cells by either laser microdissection or micromanipulation; and unbiased amplification of single-cell genomes by either linker-adaptor PCR or GenomePlex library technology. This protocol provides a suitable template to screen for chromosomal copy number changes by conventional comparative genomic hybridization (CGH) or array CGH. Expected results include the generation of several micrograms of DNA from single cells, which can be used for CGH or other analyses, such as sequencing. Using linker-adaptor PCR or GenomePlex library technology, the protocol takes 72 or 30 h, respectively.

• Delineation of a 2q deletion in a girl with dysmorphic features and epilepsy.

  Authors: Sabine Langer, Jochen B Geigl, Janine Wagenstaller, Gaby Lederer, Maja Hempel, Cornelia Daumer-Haas, Hans-Jürgen Leifheit, Michael R Speicher

  American journal of medical genetics. Part A. 05/2006; 140(7):764-8.

  In recent years, the spectrum of available methods for the characterization of chromosomal aberrations has significantly increased. Micro-array technologies now allow the rapid fine mapping of smallIn recent years, the spectrum of available methods for the characterization of chromosomal aberrations has significantly increased. Micro-array technologies now allow the rapid fine mapping of small genomic imbalances. Here we used various technologies to characterize a de novo translocation t(2;15) in a girl with dysmorphic features, severe developmental delay and frequent seizures. Multiplex-FISH (M-FISH) excluded the involvement of other chromosomes than chromosomes 2 and 15. We used an oligonucleotide array containing more than 10.000 SNPs, that is, the GeneChip Mapping 10K 2.0 SNP Affymetrix array, and readily fine-mapped a deletion in chromosomal region 2q24.1 --> 2q31.1. The extent of this deletion was verified with multicolor BAC-clone hybridizations. The deletion has a size of about 13 Mb and is within a gene rich region containing about 76 genes. Interestingly, several of these genes are ion channel genes or genes involved in neuron differentiation, so that the frequently occurring seizures are probably due to loss or haploinsufficiency of one or more of these genes.

• Multiplex-fluorescence in situ hybridization for chromosome karyotyping.

  Authors: Jochen B Geigl, Sabine Uhrig, Michael R Speicher

  Nature protocols. 02/2006; 1(3):1172-84.

  Multiplex-fluorescence in situ hybridization (M-FISH) was initially developed to stain human chromosomes--the 22 autosomes and X and Y sex chromosomes--with uniquely distinctive colors to facilitateMultiplex-fluorescence in situ hybridization (M-FISH) was initially developed to stain human chromosomes--the 22 autosomes and X and Y sex chromosomes--with uniquely distinctive colors to facilitate karyotyping. The characteristic spectral signatures of all different combinations of fluorochromes are determined by multichannel image-analysis methods. Advantages of M-FISH include rapid analysis of metaphase spreads, even in complex cases with multiple chromosomal rearrangements, and identification of marker chromosomes. The M-FISH technology has been extended to other species, such as the mouse. Furthermore, in addition to painting probes, the method has been used with a variety of region-specific probes. M-FISH has even recently been used for 3D studies to analyze the distribution of human chromosomes in intact and preserved interphase nuclei. Hence, M-FISH has evolved into an essential tool for both clinical diagnostics and basic research. In this protocol, we describe how to use M-FISH to karyotype chromosomes, a procedure that takes approximately 14 d if new M-FISH probes have to be generated and 3 d if the M-FISH probes are ready to use.

• Live cell catapulting and recultivation does not change the karyotype of HCT116 tumor cells.

  Authors: Sabine Langer, Jochen B Geigl, Susanne Ehnle, Rainer Gangnus, Michael R Speicher

  Cancer genetics and cytogenetics. 10/2005; 161(2):174-7.

  We used laser microdissection and pressure catapulting (LMPC) to isolate and subsequently recultivate cells from the colorectal cancer cell line HCT116. Cell isolation and recultivation was repeatedWe used laser microdissection and pressure catapulting (LMPC) to isolate and subsequently recultivate cells from the colorectal cancer cell line HCT116. Cell isolation and recultivation was repeated 5 times from the preceding cell culture. The chromosomal composition of the HCT116 cells was analyzed at the beginning and after each recultivation. We did not observe any additional chromosomal structural or copy number changes during this procedure. Our data suggest that the procedure of cell isolation by LMPC and subsequent recultivation does not affect the karyotype of the respective cells. This technology will facilitate the analysis of different cell populations in a heterogeneous tumor cell population.