Publications by authors named "K Mantwill"

16 Publications

  • Page 1 of 1

The Oncolytic Adenovirus XVir-N-31 as a Novel Therapy in Muscle-Invasive Bladder Cancer.

Hum Gene Ther 2019 01 3;30(1):44-56. Epub 2018 Aug 3.

1 Department of Urology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.

Muscle-invasive bladder cancer represents approximately 25% of diagnosed bladder cancer cases and carries a significant risk of death. Oncolytic viruses are novel antitumor agents with the ability to selectively replicate and lyse tumor cells while sparing healthy tissue. We explored the efficiency of the oncolytic YB-1-selective adenovirus XVir-N-31 in vitro and in an orthotopic mouse model for bladder cancer by intramural injection under ultrasound guidance. We demonstrated that XVir-N-31 replicated in bladder cancer cells and induced a stronger immunogenic cell death than wild-type adenovirus by facilitating enhanced release of HMGB1 and exosomal Hsp70. The intratumoral delivery of XVir-N-31 by ultrasound guidance delayed tumor growth in an immunodeficient model, demonstrating the feasibility of this approach to deliver oncolytic viruses directly into the tumor.
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http://dx.doi.org/10.1089/hum.2018.026DOI Listing
January 2019

Adenovirus Particle Quantification in Cell Lysates Using Light Scattering.

Hum Gene Ther Methods 2017 10 14;28(5):268-276. Epub 2017 Aug 14.

1 Klinikum Rechts der Isar, Technische Universität München , Klinik und Poliklinik für Urologie, München, Germany.

Adenoviral vector production for therapeutic applications is a well-established routine process. However, current methods for measurement of adenovirus particle titers as a quality characteristic require highly purified virus preparations. While purified virus is typically obtained in the last step of downstream purification, rapid and reliable methods for adenovirus particle quantification in intermediate products and crude lysates to allow for optimization and validation of cell cultures and intermediate downstream processing steps are currently not at hand. Light scattering is an established process to measure virus particles' size, though due to cell impurities, adequate quantification of adenovirus particles in cell lysates by light scattering has been impossible until today. This report describes a new method using light scattering to measure virus concentration in nonpurified cell lysates. Here we report application of light scattering, a routine method to measure virus particle size, to virus quantification in enzymatically conditioned crude lysates. Samples are incubated with phospholipase A2 and benzonase and filtered through a 0.22 μm filter cartridge prior to quantification by light scattering. Our results show that this treatment provides a precise method for fast and easy determination of total adenovirus particle numbers in cell lysates and is useful to monitor virus recovery throughout all downstream processing.
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http://dx.doi.org/10.1089/hgtb.2017.052DOI Listing
October 2017

Adenovirus Particle Quantification in Cell Lysates Using Light Scattering.

Hum Gene Ther Methods 2017 10 14;28(5):268-276. Epub 2017 Aug 14.

1 Klinikum Rechts der Isar, Technische Universität München , Klinik und Poliklinik für Urologie, München, Germany.

Adenoviral vector production for therapeutic applications is a well-established routine process. However, current methods for measurement of adenovirus particle titers as a quality characteristic require highly purified virus preparations. While purified virus is typically obtained in the last step of downstream purification, rapid and reliable methods for adenovirus particle quantification in intermediate products and crude lysates to allow for optimization and validation of cell cultures and intermediate downstream processing steps are currently not at hand. Light scattering is an established process to measure virus particles' size, though due to cell impurities, adequate quantification of adenovirus particles in cell lysates by light scattering has been impossible until today. This report describes a new method using light scattering to measure virus concentration in nonpurified cell lysates. Here we report application of light scattering, a routine method to measure virus particle size, to virus quantification in enzymatically conditioned crude lysates. Samples are incubated with phospholipase A2 and benzonase and filtered through a 0.22 μm filter cartridge prior to quantification by light scattering. Our results show that this treatment provides a precise method for fast and easy determination of total adenovirus particle numbers in cell lysates and is useful to monitor virus recovery throughout all downstream processing.
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http://dx.doi.org/10.1089/hgtb.2017.052DOI Listing
October 2017

YB-1 dependent oncolytic adenovirus efficiently inhibits tumor growth of glioma cancer stem like cells.

J Transl Med 2013 Sep 18;11:216. Epub 2013 Sep 18.

Institut für Experimentelle Onkologie & Therapieforschung, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str, 22, 81675 München, Germany.

Background: The brain cancer stem cell (CSC) model describes a small subset of glioma cells as being responsible for tumor initiation, conferring therapy resistance and tumor recurrence. In brain CSC, the PI3-K/AKT and the RAS/mitogen activated protein kinase (MAPK) pathways are found to be activated. In consequence, the human transcription factor YB-1, knowing to be responsible for the emergence of drug resistance and driving adenoviral replication, is phosphorylated and activated. With this knowledge, YB-1 was established in the past as a biomarker for disease progression and prognosis. This study determines the expression of YB-1 in glioblastoma (GBM) specimen in vivo and in brain CSC lines. In addition, the capacity of Ad-Delo3-RGD, an YB-1 dependent oncolytic adenovirus, to eradicate CSC was evaluated both in vitro and in vivo.

Methods: YB-1 expression was investigated by immunoblot and immuno-histochemistry. In vitro, viral replication as well as the capacity of Ad-Delo3-RGD to replicate in and, in consequence, to kill CSC was determined by real-time PCR and clonogenic dilution assays. In vivo, Ad-Delo3-RGD-mediated tumor growth inhibition was evaluated in an orthotopic mouse GBM model. Safety and specificity of Ad-Delo3-RGD were investigated in immortalized human astrocytes and by siRNA-mediated downregulation of YB-1.

Results: YB-1 is highly expressed in brain CSC lines and in GBM specimen. Efficient viral replication in and virus-mediated lysis of CSC was observed in vitro. Experiments addressing safety aspects of Ad-Delo3-RGD showed that (i) virus production in human astrocytes was significantly reduced compared to wild type adenovirus (Ad-WT) and (ii) knockdown of YB-1 significantly reduced virus replication. Mice harboring othotopic GBM developed from a temozolomide (TMZ)-resistant GBM derived CSC line which was intratumorally injected with Ad-Delo3-RGD survived significantly longer than mice receiving PBS-injections or TMZ treatment.

Conclusion: The results of this study supported YB-1 based virotherapy as an attractive therapeutic strategy for GBM treatment which will be exploited further in multimodal treatment concepts.
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http://dx.doi.org/10.1186/1479-5876-11-216DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3848904PMC
September 2013

Expression of Y-box-binding protein YB-1 allows stratification into long- and short-term survivors of head and neck cancer patients.

Br J Cancer 2011 Dec 17;105(12):1864-73. Epub 2011 Nov 17.

Department of Oral and Maxillofacial Surgery, Technische Universität München, Klinikum rechts der Isar, Ismaninger Strasse 22, Munich, Germany.

Background: Histology-based classifications and clinical parameters of head and neck squamous cell carcinoma (HNSCC) are limited in their clinical capacity to provide information on prognosis and treatment choice of HNSCC. The primary aim of this study was to analyse Y-box-binding protein-1 (YB-1) protein expression in different grading groups of HNSCC patients, and to correlate these findings with the disease-specific survival (DSS).

Methods: We investigated the expression and cellular localisation of the oncogenic transcription/translation factor YB-1 by immunohistochemistry on tissue micro arrays in a total of 365 HNSCC specimens and correlated expression data with clinico-pathological parameters including DSS.

Results: Compared with control tissue from healthy individuals, a significantly (P<0.01) increased YB-1 protein expression was observed in high-grade HNSCC patients. By univariate survival data analysis, HNSCC patients with elevated YB-1 protein expression had a significantly (P<0.01) decreased DSS. By multivariate Cox regression analysis, high YB-1 expression and nuclear localisation retained its significance as a statistically independent (P<0.002) prognostic marker for DSS. Within grade 2 group of HNSCC patients, a subgroup defined by high nuclear and cytoplasmic YB-1 levels (co-expression pattern) in the cells of the tumour invasion front had a significantly poorer 5-year DSS rate of only 38% compared with overall 55% for grade 2 patients. Vice versa, the DSS rate was markedly increased to 74% for grade 2 cancer patients with low YB-1 protein expression at the same localisation.

Conclusion: Our findings point to the fact that YB-1 expression in combination with histological classification in a double stratification strategy is superior to classical grading in the prediction of tumour progression in HNSCC.
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http://dx.doi.org/10.1038/bjc.2011.491DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3251888PMC
December 2011

YB-1 dependent virotherapy in combination with temozolomide as a multimodal therapy approach to eradicate malignant glioma.

Int J Cancer 2011 Sep 6;129(5):1265-76. Epub 2011 Jan 6.

Institut für Experimentelle Onkologie und Therapieforschung, Klinikum Rechts der Isar, Munich, Germany.

The human Y-box binding protein 1 (YB-1) is known to be a promising target for cancer therapy. We have demonstrated that YB-1 plays an important role in the adenoviral life cycle by regulating the adenoviral E2-gene expression. Thus, we studied the oncolytic effect of the recombinant adenovirus Ad-Delo3-RGD, in which the transactivation domain CR3 of the E1A protein is ablated to enable viral replication only in YB-1 positive cancer cells. In vitro Southern Blot analysis and cytopathic effect assays demonstrate high anti-glioma potency, which was significantly increased in combination with temozolomide (TMZ), daunorubicin and cisplatin. Since vascular endothelial growth factor (VEGF) is thought to promote the hypervascular phenotype of primary, malignant brain tumors, we also tested Ad-Delo3-RGD in regard to the inhibition of VEGF expression. Indeed, we found that Ad-Delo3-RGD induced VEGF down regulation, which was even amplified under hypoxic conditions. Tumor-bearing nudemice treated with the YB-1 dependent oncolytic adenovirus showed significantly smaller tumors than untreated controls. Furthermore, combination therapy with TMZ led to a regression in all treated animals with complete tumor regression in 33 % of analyzed mice, which was verified by bioluminescence imaging and histological studies. In addition, histopathological evaluation revealed enhanced apoptosis and a reduction in tumor vessel formation, indicating that Ad-Delo3-RGD has an anti-angiogenic effect in addition to its oncolytic capacity in vivo. Hence, our results demonstrate that the combination therapy of YB-1 dependent virotherapy and TMZ is effective in a xenograft glioma mouse model and might be useful in a YB-1 based clinical setting.
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http://dx.doi.org/10.1002/ijc.25783DOI Listing
September 2011

Are effects of emotion in single words non-lexical? Evidence from event-related brain potentials.

Neuropsychologia 2011 Jul 12;49(9):2766-75. Epub 2011 Jun 12.

Department of Psychology, Humboldt-Universität zu Berlin, Germany.

Emotional meaning impacts word processing. However, it is unclear, at which functional locus this influence occurs and whether and how it depends on word class. These questions were addressed by recording event-related potentials (ERPs) in a lexical decision task with written adjectives, verbs, and nouns of positive, negative, and neutral emotional valence. In addition, word frequency (high vs. low) was manipulated. The early posterior negativity (EPN) in ERPs started earlier for emotional nouns and adjectives than for verbs. Depending on word class, EPN onsets coincided with or followed the lexicality effects. Main ERP effects of emotion overlapped with effects of word frequency between 300 and 550 ms but interacted with them only after 500 ms. These results indicate that in all three word classes examined, emotional evaluation as represented by the EPN has a post-lexical locus, starting already after a minimum of lexical access.
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http://dx.doi.org/10.1016/j.neuropsychologia.2011.06.005DOI Listing
July 2011

Adenovirus-based virotherapy enabled by cellular YB-1 expression in vitro and in vivo.

Cancer Gene Ther 2009 Oct 10;16(10):753-63. Epub 2009 Apr 10.

Institute of Experimental Oncology and Therapeutics, Klinikum Rechts der Isar, Technische Universitaet Muenchen, Muenchen 81675, Germany.

We have earlier described the oncolytic adenovirus vector dl520 that was rendered cancer-specific by deletion of the transactivation domain CR3 of the adenoviral E1A13S protein; this deletion causes antitumor activity in drug-resistant cells displaying nuclear YB-1 expression. We hypothesized that the anticancer activity of dl520 could be further improved by introducing the RGD motif in the fiber knob and by deletion of the adenoviral E1B19K protein (Ad-Delo3-RGD). In this study, the in vitro and in vivo antitumor activity of Ad-Delo3-RGD was investigated focussing on two pancreatic cancer cell lines MiaPaCa-2 and BxPC3 alone and in combination with cytotoxic drugs. Furthermore, luciferin-based bioluminescence imaging was established to study the therapeutic response in vivo. In addition, to confirm the specificity of Ad-Delo3-RGD for YB-1 a tetracycline-inducible anti-YB-1 shRNA-expressing cell variant EPG85-257RDB/tetR/YB-1 was used. This TetON regulatable expression system allows us to measure adenoviral replication by real-time PCR in the absence of YB-1 expression. The results confirmed the YB-1 dependency of Ad-Delo3-RGD and showed that Ad-Delo3-RGD has potent activity against human pancreatic cancer cells in vitro and in vivo, which was augmented by the addition of paclitaxel. However, although high replication capacity was measured in vitro and in vivo, complete tumor regression was not achieved, indicating the need for further improvements to treat pancreatic cancer effectively.
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http://dx.doi.org/10.1038/cgt.2009.20DOI Listing
October 2009

Impact of radiation therapy on the oncolytic adenovirus dl520: implications on the treatment of glioblastoma.

Radiother Oncol 2008 Mar 29;86(3):419-27. Epub 2007 Oct 29.

Institute of Experimental Oncology, Technical University of Munich, Germany.

Background And Purpose: Viral oncolytic therapy is emerging as a new form of anticancer therapy and has shown promising preclinical results, especially in combination with radio- and chemotherapy. We recently reported that nuclear localization of the human transcription factor YB-1 in multidrug-resistant cells facilitates E1-independent adenoviral replication. The aim of this study was to evaluate the combined treatment of the conditionally-replicating adenovirus dl520 and radiotherapy in glioma cell lines in vitro and in human tumor xenografts. Furthermore, the dependency of YB-1 on dl520 replication was verified by shRNA directed down regulation of YB-1.

Methods And Material: Localization of YB-1 was determined by immunostaining. Glioma cell lines LN-18, U373 and U87 were infected with dl520. Induction of cytopathic effect (CPE), viral replication, viral yield and viral release were determined after viral infection, radiation therapy and the combination of both treatment modalities. The capacity of treatments alone or combined to induce tumor growth inhibition of subcutaneous U373 tumors was tested also in nude mice.

Results: Quantitative real-time PCR demonstrated that the shRNA-mediated down regulation of YB-1 is leading to a dramatic decrease in adenoviral replication of dl520. Immunostaining analysis showed that the YB-1 protein was predominantly located in the cytoplasm in the perinuclear space and less abundant in the nucleus. After irradiation we found an increase of nuclear YB-1. The addition of radiotherapy increased the oncolytic effect of dl520 with enhanced viral replication, viral yield and viral release. The oncolytic activity of dl520 plus radiation inhibited the growth of subcutaneous U373 tumors in a xenograft mouse model.

Conclusions: Radiation mediated increase of nuclear YB-1 in glioma cells enhanced the oncolytic potential of adenovirus dl520.
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http://dx.doi.org/10.1016/j.radonc.2007.10.009DOI Listing
March 2008

Inhibition of the multidrug-resistant phenotype by targeting YB-1 with a conditionally oncolytic adenovirus: implications for combinatorial treatment regimen with chemotherapeutic agents.

Cancer Res 2006 Jul;66(14):7195-202

Institute of Experimental Oncology and Department of Urology, Technical University of Munich, Klinikum rechts der Isar, Germany.

Bearing in mind the limited success of available treatment modalities for the therapy of multidrug-resistant tumor cells, alternative and complementary strategies need to be developed. It is known that the transcriptional activation of genes, such as MDR1 and MRP1, which play a major role in the development of a multidrug-resistant phenotype in tumor cells, involves the Y-box protein YB-1. Thus, YB-1 is a promising target for new therapeutic approaches to defeat multidrug resistance. In addition, it has been reported previously that YB-1 is an important factor in adenoviral replication because it activates transcription from the adenoviral E2-late promoter. Here, we report that an oncolytic adenovirus, named Xvir03, expressing the viral proteins E1B55k and E4orf6, leads to nuclear translocation of YB-1 and in consequence to viral replication and cell lysis in vitro and in vivo. Moreover, we show that Xvir03 down-regulates the expression of MDR1 and MRP1, indicating that recruiting YB-1 to the adenoviral E2-late promoter for viral replication is responsible for this effect. Thus, nuclear translocation of YB-1 by Xvir03 leads to resensitization of tumor cells to cytotoxic drugs. These data reveal a link between chemotherapy and virotherapy based on the cellular transcription factor YB-1 and provide the basis for formulating a model for a novel combined therapy regimen named Mutually Synergistic Therapy.
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http://dx.doi.org/10.1158/0008-5472.CAN-05-2339DOI Listing
July 2006

Characterization of the recombinant adenovirus vector AdYB-1: implications for oncolytic vector development.

J Virol 2006 Apr;80(8):3904-11

Institut fuer Experimentelle Onkologie und Therapieforschung, Technische Universitaet Muenchen, Klinikum rechts der Isar, Ismaninger Str. 22, 81675 Munich, Germany.

Conditionally replicating adenoviruses are a promising new modality for the treatment of cancer. However, early clinical trials demonstrate that the efficacy of current vectors is limited. Interestingly, DNA replication and production of viral particles do not always correlate with virus-mediated cell lysis and virus release depending on the vector utilized for infection. However, we have previously reported that nuclear accumulation of the human transcription factor YB-1 by regulating the adenoviral E2 late promoter facilitates viral DNA replication of E1-deleted adenovirus vectors which are widely used for cancer gene therapy. Here we report the promotion of virus-mediated cell killing as a new function of the human transcription factor YB-1. In contrast to the E1A-deleted vector dl312 the first-generation adenovirus vector AdYB-1, which overexpresses YB-1 under cytomegalovirus promoter control, led to necrosis-like cell death, virus production, and viral release after infection of A549 and U2OS tumor cell lines. Our data suggest that the integration of YB-1 in oncolytic adenoviruses is a promising strategy for developing oncolytic vectors with enhanced potency against different malignancies.
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http://dx.doi.org/10.1128/JVI.80.8.3904-3911.2006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1440461PMC
April 2006

Novel three-pronged strategy to enhance cancer cell killing in glioblastoma cell lines: histone deacetylase inhibitor, chemotherapy, and oncolytic adenovirus dl520.

Hum Gene Ther 2006 Jan;17(1):55-70

Institute of Experimental Oncology, Technical University of Munich, Klinikum Rechts-der-Isar, 81675 Munich, Germany.

Resistance to radiation and chemotherapy remains an obstacle to the treatment of brain tumors. We have demonstrated that the replication-deficient adenovirus d1520, which lacks the E1A 13S protein, replicates efficiently and exhibits oncolytic potential in multidrug-resistant cells with nuclear localization of the human transcription factor YB-1. However, besides others, key factors regarding oncolytic virotherapy are limited tumor transduction rate and low replication efficiency. The objective of this study was to determine whether the chemotherapeutic agent irinotecan, by enhancing nuclear localization of YB-1, and the histone deacetylase inhibitor trichostatin A, by upregulating coxsackievirus-adenovirus receptor (CAR) expression, could augment replication of and cell lysis by adenovirus dl520 in glioblastomas in vitro. We found that trichostatin A upregulated CAR expression and that irinotecan caused increased nuclear localization of YB-1 in both glioblastoma cell lines. Irinotecan alone, and trichostatin A alone, enhanced replication of and cell lysis by dl520. Importantly, when combining both agents, the replication efficiency (maximum, 27-fold) and induction of cytopathic effect (maximum, 3.8-fold) of dl520 were further augmented significantly. These results support the hypothesis that the enhanced oncolytic effect of dl520, after incubation with chemotherapeutic agents, is mediated by an increased accumulation of YB-1 in the nucleus (due to irinotecan) and by upregulation of CAR (due to trichostatin A). Thus, therapy combining virotherapy, chemotherapy, and histone deacetylase inhibitor treatment is a novel approach to enhance the oncolytic efficacy of dl520.
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http://dx.doi.org/10.1089/hum.2006.17.55DOI Listing
January 2006

Multidrug-resistant cancer cells facilitate E1-independent adenoviral replication: impact for cancer gene therapy.

Cancer Res 2004 Jan;64(1):322-8

Institut für Experimentelle Onkologie und Therapieforschung, Technische Universität München, Klinikum Rechts der Isar, München, Germany.

Resistance to chemotherapy is responsible for a failure of current treatment regimens in cancer patients. We have reported previously that the Y-box protein YB-1 regulates expression of the P-glycoprotein gene mdr1, which plays a major role in the development of a multidrug resistant-tumor phenotype. YB-1 predicts drug resistance and patient outcome in breast cancer. Thus, YB-1 is a promising target for new therapeutic approaches to defeat multidrug resistance. In drug-resistant cancer cells and in adenovirus-infected cells YB-1 is found in the nucleus. Nuclear accumulation of YB-1 in adenovirus-infected cells is a function of the E1 region, and we have shown that YB-1 facilitates adenovirus replication. Here we report that E1A-deleted or mutant adenovirus vectors, such as Ad312 and Ad520, replicate efficiently in multidrug-resistant (MDR) cancer cells and induce an adenovirus cytopathic effect resulting in host cell lysis. Thus, replication-defective adenoviruses are a previously unrecognized vector system for a selective elimination of MDR cancer cells. Our work forms the basis for the development of novel oncolytic adenovirus vectors for the treatment of MDR malignant diseases in the clinical setting.
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http://dx.doi.org/10.1158/0008-5472.can-0482-2DOI Listing
January 2004

YB-1 relocates to the nucleus in adenovirus-infected cells and facilitates viral replication by inducing E2 gene expression through the E2 late promoter.

J Biol Chem 2002 Mar 11;277(12):10427-34. Epub 2002 Jan 11.

Institut für Experimentelle Onkologie und Therapieforschung, Technische Universität München, Klinikum Rechts der Isar, München 81675, Germany.

The adenovirus early proteins E1A and E1B-55kDa are key regulators of viral DNA replication, and it was thought that targeting of p53 by E1B-55kDa is essential for this process. Here we have identified a previously unrecognized function of E1B for adenovirus replication. We found that E1B-55kDa is involved in targeting the transcription factor YB-1 to the nuclei of adenovirus type 5-infected cells where it is associated with viral inclusion bodies believed to be sites of viral transcription and replication. We show that YB-1 facilitates E2 gene expression through the E2 late promoter thus controlling E2 gene activity at later stages of infection. The role of YB-1 for adenovirus replication was demonstrated with an E1-minus adenovirus vector containing a YB-1 transgene. In infected cells, AdYB-1 efficiently replicated and produced infectious progeny particles. Thus, adenovirus E1B-55kDa protein and the host cell factor YB-1 act jointly to facilitate adenovirus replication in the late phase of infection.
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http://dx.doi.org/10.1074/jbc.M106955200DOI Listing
March 2002

Identification of differentially expressed genes in human melanoma cells with acquired resistance to various antineoplastic drugs.

Int J Cancer 2000 Nov;88(4):535-46

Institute of Pathology, Charité, Campus Mitte, Humboldt University Berlin, Berlin, Germany.

Malignant melanoma displays strong resistance against various antineoplastic drugs. The mechanisms conferring this intrinsic resistance are unclear. To better understand the molecular events associated with drug resistance in melanoma, a panel of human melanoma cell variants exhibiting low and high levels of resistance to 4 commonly used drugs in melanoma treatment, i.e., vindesine, etoposide, fotemustine and cisplatin, was characterized by differential display reverse transcription-polymerase chain reaction (DDRT-PCR). Of 269 mRNA fragments found to be altered in expression level by DDRT-PCR, a total of 11 cDNA clones was characterized after confirmation of a differential expression pattern by Northern blot analyses. These clones include 3 genes (DSM-1, DSM-3 and DSM-5) of known function, 4 previously sequenced genes (DSM-2, DSM-4, DSM-6 and DSM-7) of uncharacterized function and 4 novel genes (DSM-8-DSM-11) without match in GenBank. All of these genes exhibited altered mRNA expression in high level etoposide-resistant cells, whereby 7 genes (DSM-1-DSM-6 and DSM-8) were found to be decreased in the transcription rate in these etoposide-resistant cells. The mRNA synthesis of the remaining genes (DSM-7 and DSM-9-DSM11) was enhanced in high level etoposide-resistant melanoma cells. The expression of 5 (DSM-5 and DSM-7-DSM-10) of the cloned cDNA encoding mRNAs was modulated in various independently established drug-resistant melanoma cells, indicating to be associated with drug resistance. Further characterization of these genes may yield inside into the biology and development of drug resistance in malignant melanoma.
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http://dx.doi.org/10.1002/1097-0215(20001115)88:4<535::aid-ijc4>3.0.co;2-vDOI Listing
November 2000

Characterization of a MAb to ovarian cancer and its possible diagnostic application.

Eur J Gynaecol Oncol 1999 ;20(4):289-97

Dept. of Obstetrics and Gynaecology, University of Kiel, Germany.

We report the distribution pattern of the target antigen of an IgG1 monoclonal antibody, Ki-OC III raised in BALB/C mice against solubilised ovarian adenocarcinoma, in normal tissue and in a collection of human tumour types. Special reference was made to benign and malignant ovarian tumours. The reactive antigen protein purified to homogeneity for a planned amino acid analysis showed three bands between 37-40 kDa. Immunohistochemical analysis revealed a specificity of 98% and a sensitivity of 77%. The tracer kinetics of the radiolabelled antibody were tested on a human ovarian carcinoma cell line in athymic mice. The results were compared to cell lines derived from breast and stomach carcinomas as well as to a human glioblastoma cell line. The results show the preferential uptake by ovarian cancer cells followed by breast cancer cell lines. In animal models, scintigraphic monitoring and direct measurement of the radio-labelled monoclonal antibody showed a preferential accumulation in tumours, in addition to high level signals in the liver, kidney, spleen and heart which were related to degradation, excretion and high circulation. The Ki-OC III reactive antigen could be a potential candidate for immunomonitoring of ovarian and possibly also of breast cancer, for in vivo tumour imaging as well as for histopathologic examinations.
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November 1999