Iver Petersen

Diversity of gene expression in adenocarcinoma of the lung.

The global gene expression profiles for 67 human lung tumors representing 56 patients were examined by using 24,000-element cDNA microarrays. Subdivision of the tumors based on gene expression patterns faithfully recapitulated morphological classification of the tumors into squamous, large cell, small cell, and adenocarcinoma. The gene expression patterns made possible the subclassification of adenocarcinoma into subgroups that correlated with the degree of tumor differentiation as well as patient survival. Gene expression analysis thus promises to extend and refine standard pathologic analysis.

Genetic Imbalances with Impact on Survival in Head and Neck Cancer Patients

Chromosomal imbalances in 113 primary head and neck squamous cell carcinomas (HNSCCs) determined by comparative genomic hybridization were correlated with patients survival using custom-made computer software which enabled the assessment of individual chromosomal loci. The Kaplan-Meier analysis revealed that overrepresentations of 2q12, 3q21-29, 6p21.1, 11q13, 14q23, 14q24, 14q31, 14q32, 15q24, 16q22, and deletions of 8p21-22 and 18q11.2 were significantly associated with both shorter disease-free interval and disease-specific survival in this tumor collective. Multivariate Cox proportional hazards regression models consistently identified the gains of 3q21-29, 11q13, and the loss of 8p21-22 as independent prognostic markers carrying a higher significance than the nodal status as the only clinicopathological parameter with statistical importance. In addition, these three markers allowed a molecular dissection of the patients with low clinical risk (pN0 and pT2 tumors). Thus, the genomic data being derived from the evaluation of primary HNSCC enabled a stratification of the patients into subgroups with different survival highlighting the necessity of a genetically based tumor classification for refining diagnosis and treatment of HNSCC patients.

Nuclear export is essential for the tumor-promoting activity of survivin

Survivin appears to function as an apoptosis inhibitor and a regulator of cell division during development and tumorigenesis. Here we report the molecular characterization of the nucleocytoplasmic transport of survivin and its potential implications for tumorigenesis. We identified an evolutionary conserved Crm1‐dependent nuclear export signal (NES) in survivin. In dividing cells, the NES is essential for tethering survivin and the survivin/Aurora‐B kinase complex to the mitotic machinery, which in turn appears to be essential for proper cell division. In addition, export seems to be required for the cytoprotective activity of survivin, as export‐deficient survivin fails to protect tumor cells against chemo‐and radiotherapy‐induced apoptosis. These findings appear to be clinically relevant since preferential nuclear localization of survivin correlated with enhanced survival in colorectal cancer patients. Targeting survivins nuclear export by the application of NES‐specific antibodies promoted its nuclear accumulation and inhibited its cytoprotective function. We demonstrate that nuclear export is essential for the biological activity of survivin and promote the identification of molecular decoys to specifically interfere with survivins nuclear export as potential anticancer therapeutics. Knauer, S. K., Krämer, O. H., Knösel, T., Engels, K., Rödel, F., Kovács, A. F., Dietmaier, W., Klein‐Hitpass, L., Habtemichael, N., Schweitzer, A., Brieger, J., Rödel, C., Mann, W., Petersen, I., Heinzel, T., Stauber, R. H. Nuclear export is essential for the tumor‐promoting activity of survivin. FASEB J. 21, 207–216 (2007)

Prediction of doxorubicin sensitivity in breast tumors based on gene expression profiles of drug-resistant cell lines correlates with patient survival

Up to date clinical tests for predicting cancer chemotherapy response are not available and individual markers have shown little predictive value. We hypothesized that gene expression patterns attributable to chemotherapy-resistant cells can predict response and cancer prognosis. We contrasted the expression profiles of 13 different human tumor cell lines of gastric (EPG85–257), pancreatic (EPP85–181), colon (HT29) and breast (MCF7 and MDA-MB-231) origin and their counterparts resistant to the topoisomerase inhibitors daunorubicin, doxorubicin or mitoxantrone. We interrogated cDNA arrays with 43u2009000 cDNA clones (∼30u2009000 unique genes) to study the expression pattern of these cell lines. We divided gene expression profiles into two sets: we compared the expression patterns of the daunorubicin/doxorubicin-resistant cell lines and the mitoxantrone-resistant cell lines independently to the parental cell lines. For identifying predictive genes, the Prediction Analysis for Mircorarrays algorithm was used. The analysis revealed 79 genes best correlated with doxorubicin resistance and 70 genes with mitoxantrone resistance. In an independent classification experiment, we applied our model of resistance for predicting the sensitivity of 44 previously characterized breast cancer samples. The patient group characterized by the gene expression profile similar to those of doxorubicin-sensitive cell lines exhibited longer survival (49.7±26.1 months, n=21, P=0.034) than the resistant group (32.9±18.7 months, n=23). The application of gene expression signatures derived from doxorubicin-resistant and -sensitive cell lines allowed to predict effectively clinical survival after doxorubicin monotherapy. Our approach demonstrates the significance of in vitro experiments in the development of new strategies for cancer response prediction.

Telepathology by the Internet

A new concept for telemicroscopy has recently been introduced using the Internet and conventional web browser, with Java support for microscope remote control as well as image transfer and discussion (http://amba.charite.de/telemic/) . The system has two major components: the telemicroscopy server, which is a computer with Internet access connected to the automatic microscope, and the telemicroscopy client, who remotely operates the microscope. This simplified telemicroscopy system allows any Internet user to become a consultant for telepathology without the acquisition of specialized hardware or software. For the inquirer seeking advice, however, this solution is still very expensive, since it requires a fully automated microscope. The present study describes a system that can be used for conventional microscopes. A video camera mounted on a microscope with a photo tube is connected to the frame grabber of a PC. Java‐based telemicroscopy software transforms the computer into an Internet server, which automatically distributes new microscope images, after manual operations, to all connected clients. Any Internet user can access the web page of the server to become a telemicroscopy client. A Chat function allows for the online exchange of written text and a Discuss function enables the mouse button to display an arrow to all connected clients, which highlights distinct structures of the images. The system was optimized for simplicity, while presenting all features that are necessary to show and discuss difficult cases with any expert in the field who has Internet access. It offers new perspectives for telepathology and it is envisaged that many pathologists and scientists will use this facility to connect their personal microscopes to the Internet, forming a network for teleconsultation. To foster this development, the software described in this paper is being made freely available. Hopefully, this development will promote communication between pathologists and may thus increase the quality of diagnosis. Information on inquiry and installation of the software is available at the website mentioned above. Telemicroscopy sessions using the Telemic version for conventional microscopes can be scheduled by contacting the authors by e‒mail (iver.petersen@charite.de). Copyright

CGH pattern of esthesioneuroblastoma and their metastases.

Comparative genomic hybridization (CGH) was used to screen 22 esthesioneuroblastomas (ENB) from 12 patients including 12 primary tumors and 10 metastasis/recurrent lesions for chromosomal imbalances being the most extensive study so far. The analysis revealed a characteristic pattern consisting of deletions on chromosomes 3p and overrepresentations on 17q in up to 100% of cases. Other important alterations being detectable in more than 80% of cases were deletions on 1 p, 3p/q, 9p, 10p/q along with overrepresentation on 17p13, 20p and 22q. Particularly striking was the pattern for chromosomes 3, 10 and 17q and 20 being affected almost exclusively by deletions or overrepresentations, respectively. Pronounced overrepresentations suggestive for high copy amplifications were seen on 1p34, 1q23‐q31, 7p21, 7q31, 9p23‐p24, 17q11‐q22, 17q24‐q25, 19, 20p, 20q13 and 22q13. Comparing tumor pairs from the same patient revealed a high concordance indicating clonality and confirming the genetic homogeneity of the tumor entity. The analysis of metastatic/recurrent lesions indicated a higher percentage of pronounced alterations, eg, high copy DNA gains at 1q34‐qter, 7q11, 9p23‐p24, 9q34, 13q33‐q34, 16p13.3, 16p11, 16q23‐q24 and 17p13.The analysis furthermore suggested specific alterations, eg, deletions of chromosome 11 and gains of 1p to be associated with metastasis formation and/or worse prognosis. Our results indicate that ENB is a distinct entity and provides criteria for its genetic distinction from other small round cell tumor types.

DNA ploidy and chromosomal alterations in head and neck squamous cell carcinoma

Abstract. In head and neck squamous cell carcinomas (HNSCC) the prognostic factors that are routinely considered when deciding therapeutic strategies are still stage and site of the primary tumour, and the presence of nodal or distant metastases. However, it is recognised that these clinical predictors are limited since they do not satisfactorily reflect the biological behaviour of the individual tumour. With the evolving understanding of the genetic and molecular basis of human malignancies, there are an increasing number of factors being claimed to provide prognostic information even in HNSCC. Here we review own and published data on DNA ploidy, karyotyping and molecular cytogenetic changes and its relevance in HNSCC carcinogenesis. The survey suggests that the induction of aneuploidy is a very early event in tumour development being detectable already in non-dysplastic leukoplakia and highly predictive for the subsequent development of a carcinoma. Moreover, specific chromosomal imbalances are associated with different stages of cancer progression and patients survival, which we have compiled into a progression model of HNSCC.

Chromosomal imbalances in wood dust-related adenocarcinomas of the inner nose and their associations with pathological parameters.

Comparative genomic hybridization (CGH) was used to screen 42 wood dust‐related sinonasal adenocarcinomas for chromosomal alterations. The tumour collection comprised 39 papillary‐tubular cylinder cell adenocarcinomas (PTCCs; six cases G1, 23 G2, and ten G3), two alveolar goblet cell adenocarcinomas (AGCs), and one signet ring cell adenocarcinoma (SRC), according to the Kleinsasser and Schroeder classification. Copy number changes were detected in 41 tumours (97.6%). The one carcinoma without imbalances was a PTCC‐G1. DNA gains were most frequently seen on chromosomes 12p (83%), 7q (74%), 8q (71%), and 20q (71%), 11q (61%), 22 (59%), and 1q (52%). Pronounced overrepresentations suggestive of high copy amplifications were detected on 8q (15 cases, 36%), 7q (six cases, 14%), 20q (five cases, 12%), 13q14 (three cases, 7%), 1q22, 5p, 12p and 20 (two cases, 5% each), and 2q24, 3q13, 3q22, 7p, 14q12, and 16q13 (one case, each 2%). Frequent chromosomal losses occurred at 5q (81%), 18q (76%), 4 (74%), 8p (61%), 9p (60%), 6q and 17p (52% each), and 3p, 13q, and 21 (50% each). There was a quantitative as well as a qualitative increase of alterations from PTCC‐G1 to PTCC‐G2 and finally PTCC‐G3, confirming the usefulness of histopathological grading. While PTCC‐G1 carried only a few alterations, namely gains on chromosomes 17 and 7 as well as losses of 4q and 13q, PTCC‐G2 already carried many of the above‐mentioned alterations, while PTCC‐G3 showed significantly more gains of 7q, 8q, and 12p, and losses of 8p and 17p. Additionally, the latter subgroup was particularly prone to carry pronounced DNA gains. These data provide further evidence for a recurrent pattern of chromosomal imbalances in sinonasal adenocarcinomas and highlight distinct aberrations that are associated with tumour differentiation and progression. Copyright

Antiangiogenesis, anti-VEGF(R) and outlook.

Tumor angiogenesis and antiangiogenesis has moved from an exotic research topic into clinical practice defining a new and promising avenue of targeted cancer therapy. Starting with a historical perspective on tumor angiogenesis, this review provides the basic concepts and classification of angiogenesis inhibition. Focusing primarily on vascular endothelial growth factor (VEGF), the biological activity and regulation of the gene expression of VEGF, its isoforms, and the receptors are summarized. Furthermore, naturally occurring modulators are listed, an overview on angiogenesis inhibitors in clinical trails is provided, and finally a brief outlook is given on this fascinating and rapidly evolving field of oncology.

Molecular cytogenetic characterization of epithelioid hemangioendothelioma

Epithelioid hemangioendothelioma (EHE) is a rare vascular tumor whose pathological diagnosis can be difficult. In the literature two cases of EHE were found to harbor a balanced t(1;3)(p36.3;q25) translocation, suggesting a characteristic chromosomal rearrangement as cause for the development of EHE. In this study, 14 cases of EHE were investigated by interphase fluorescence in situ hybridization (FISH) directed against the translocation breakpoint 1p36.3. A subset of cases was also analyzed by comparative genomic hybridization (CGH) and image cytometry. Five out of eight cases that could be successfully analyzed by FISH harbored a chromosomal break in the 1p36.3 region. The break-apart signals were present in diploid nuclei, and less frequently also in tetraploid nuclei. In the latter, the chromosomal break was present twice, suggesting that polyploidy occurred after the chromosomal alteration. DNA cytometry confirmed that tetraploid cells were present in most examined cases with one case indicating almost equal amounts of diploid and tetraploid tumor cells. CGH revealed single chromosomal imbalances of unclear significance. We could confirm that EHE may harbor a recurrent mutation involving the 1p36.3 chromosomal region thus supporting the notion that the t(1;3)(p36.3;q25) translocation is a relevant genetic finding in this tumor entity.