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Lukas Bubendorf

Publications and source records attributed to Lukas Bubendorf.

35 records · Page 2Linked to original sources
PubMed2004

Nonsense-mediated decay microarray analysis identifies mutations of EPHB2 in human prostate cancer.

The identification of tumor-suppressor genes in solid tumors by classical cancer genetics methods is difficult and slow. We combined nonsense-mediated RNA decay microarrays and array-based comparative genomic hybridization for the genome-wide identification of genes with biallelic inactivation involving nonsense mutations and loss of the wild-type allele. This approach enabled us to identify previously unknown mutations in the receptor tyrosine kinase gene EPHB2. The DU 145 prostate cancer cell line, originating from a brain metastasis, carries a truncating mutation of EPHB2 and a deletion of the remaining allele. Additional frameshift, splice site, missense and nonsense mutations are present in clinical prostate cancer samples. Transfection of DU 145 cells, which lack functional EphB2, with wild-type EPHB2 suppresses clonogenic growth. Taken together with studies indicating that EphB2 may have an essential role in cell migration and maintenance of normal tissue architecture, our findings suggest that mutational inactivation of EPHB2 may be important in the progression and metastasis of prostate cancer.

Cell Line, Tumor↗
PubMed2004

Montelukast and Churg-Strauss syndrome.

The association of leukotriene receptor antagonists and Churg-Strauss Syndrome (CSS) has been recognised for several years. However, whether these drugs have a direct pathogenic role remains controversial. The present case describes an asthmatic patient, who developed severe obstructive symptoms and progressive heart failure after two sequential exposures to montelukast. As the patient exhibited a markedly raised blood eosinophil count with diffuse infiltrates on chest x-ray and signs of myocarditis, CSS was suspected. The disease was confirmed by open lung biopsy. The symptoms improved rapidly after administration of high dose immunosuppression with methylprednisolone and cyclophosphamide. This case is noteworthy because the time course of events strongly suggests a direct aetiological role for montelukast in the development of CSS. The pathophysiological mechanism of the association remains unknown.

Acetates↗
PubMed2004

Signal transducer and activator of transcription-5 activation and breast cancer prognosis.

PURPOSE: Transcription factor signal transducer and activator of transcription-5 (Stat5) promotes breast epithelial cell differentiation. We retrospectively analyzed whether levels of active Stat5 in breast cancer were linked to clinical outcome. MATERIALS AND METHODS: Immunohistochemistry was used to detect active, tyrosine-phosphorylated Stat5 in paraffin-embedded breast cancer specimens from three archival tissue microarray materials A, B, and C. Material A included 19 healthy human breast tissues and a progression series of primary lymph node-negative, primary lymph node-positive, and metastatic breast cancer (n = 400). Materials B (n = 785) and C (n = 570) represented two independent arrays of unselected primary breast cancer specimens with clinical follow-up data. RESULTS: Material A demonstrated that Stat5 activation, but not Stat5 protein expression, was gradually lost during cancer progression, with detectable activation in 100% of healthy breast specimens compared with less than 20% of node-positive breast cancers and metastases. Stat5 activation in tumors of material B was associated with favorable prognosis. This observation was confirmed and extended in material C to include both breast cancer-specific survival and disease-free survival. Stat5 activation remained an independent prognostic marker after adjusting for patient age, tumor size, histological grade, estrogen receptor, progesterone receptor, and Her2/neu status by Cox multivariate analysis (hazard ratio, 2.0; P =.029). Stat5 activation was a particularly favorable marker in the lymph node-negative breast cancer subpopulation (hazard ratio, 7.5; P =.003). CONCLUSION: In our study, active Stat5 distinguishes breast cancer patients with favorable prognosis, and may be a useful marker for selection of more individualized treatment, especially in localized disease. These findings require confirmation in a large prospective study.

Adult↗
PubMed2004

Prognostic impact of ANX7-GTPase in metastatic and HER2-negative breast cancer patients.

PURPOSE: ANX7-GTPase located on chromosome 10q21 is significantly altered and associated with hormone-refractory metastatic prostate cancers. Therefore, we investigated whether levels of ANX7 correlate with breast cancer progression and survival EXPERIMENTAL DESIGN: A diagnostic tumor tissue microarray containing 525 human breast tissue specimens at different stages of the disease was assayed for ANX7 using immunocytochemical methods with ANX7 monoclonal antibody. A separate prognostic tumor tissue microarray containing 553 human breast tissue specimens annotated with clinicopathological parameters was assayed for ANX7, HER2, estrogen receptor, progesterone receptor, and p53 protein. RESULTS: We report here for the first time that the expression of ANX7-GTPase is significantly enhanced and associated with the presence of metastatic disease (P < 0.0001) in the 525 human breast tissue specimens analyzed. Furthermore, using a separate 553 case retrospective prognostic tumor tissue microarray, we found that increased ANX7 expression is also significantly associated with poor overall patient survival (P < 0.014). This is particularly true when restricted to patients in whom the BRE clinical grade is 2 (P < 0.001) or for whom there is a lack of HER2 expression (P < 0.002). Finally, Cox regression analysis shows that as the expression of ANX7 rises, the probability of survival decreases by more than 10-fold for those patients with HER2-negative tumors. These latter patients represented 66% of the population affected with breast cancer in this study. CONCLUSIONS: High levels of ANX7 in tumor correlate strongly with poor survival of HER2-negative patients and the most aggressive forms of breast cancer. This is the first study to demonstrate that ANX7 antibody has the potential for development into an in vivo diagnostic and therapeutic tool. This simple and reliable immunohistochemical assay may therefore become an important biomarker for metastatic breast cancer diagnosis and management of HER2-negative breast tumor patients.

Adult↗
PubMed2004

Macrofollicular variant of papillary carcinoma of the thyroid: a histologic, cytologic, and immunohistochemical study of 3 cases and review of the literature.

CONTEXT: The macrofollicular variant of papillary carcinoma of the thyroid is a rare entity described by J. Albores-Saavedra and colleagues in 1991. It is characterized histologically by a predominance of macrofollicles and clinically by a low incidence of metastasis. This entity may represent a source of diagnostic error, since it can be easily misinterpreted as a macrofollicular adenoma or nodular goiter. DESIGN: In this study, we describe 3 cases of papillary carcinoma of the thyroid with a macrofollicular growth pattern and review the literature. RESULTS: The fine-needle aspiration biopsies in 2 cases showed large cells with optically clear nuclei and nuclear grooves, suggestive of papillary carcinoma of the thyroid. In one case, the cytology showed no signs of malignancy. In all cases, the tumors showed a combination of the conventional follicular variant of papillary carcinoma of the thyroid and macrofollicles (diameter, >250 microm) occupying more than 50% of the cross-sectional area. Cytologic features were large, cuboidal cells with optically clear, ground-glass nuclei with smooth outlines, a fine chromatin pattern, nuclear grooves, and pseudoinclusions. The colloid was dense and more eosinophilic than in adjacent normal follicles. In 2 cases, there was capsular or blood vessel infiltration, and one tumor had metastasized to a cervical lymph node. One tumor recurred 1 year later as an anaplastic carcinoma. Immunohistochemical staining showed a positivity of the tumor cells for cytokeratins 7, 17, and 19, thyroid transcription factor-1, and galectin-3 and a negativity for cytokeratin 20 and p53. CONCLUSIONS: Although it has been suggested that this tumor is a highly differentiated variant with a favorable prognosis, our study shows that its biologic behavior is not conclusive because metastases and recurrences with dedifferentiation may occur.

Adult↗
PubMed2003

Elevated expression of inhibitor of apoptosis proteins in prostate cancer.

PURPOSE: Inhibitor of apoptosis (IAP) family proteins are suppressors of apoptosis that have been implicated in apoptosis resistance in some cancers. Their expression and relevance to the prognosis of prostate cancer were investigated. EXPERIMENTAL DESIGN: The expression of four members of the IAP family (cellular inhibitor of apoptosis protein 1, cellular inhibitor of apoptosis protein 2, X chromosome-linked IAP, and survivin) was examined by immunohistochemistry and immunoblotting in human prostate cancers and in prostate tissues from transgenic mice expressing SV40 large T antigen under control of a probasin promoter. RESULTS: Tumor-associated elevations in the levels of all four IAP family members were common in prostate cancers of both humans and mice, suggesting concomitant up-regulation of multiple IAP family proteins. Compared with normal prostatic epithelium, increased IAP expression was often evident even in prostatic intraepithelial neoplasia lesions (carcinoma in situ), suggesting that deregulation of IAP expression occurs early in the pathogenesis of prostate cancer. IAP expression did not correlate with Gleason grade or prostate-specific antigen levels. CONCLUSIONS: The findings demonstrate that tumor- associated elevations in the expression of several IAP family proteins occur as a frequent and early event in the etiology of prostate cancer.

Animals↗
PubMed2003

Expression of NKX3.1 in normal and malignant tissues.

BACKGROUND: NKX3.1, a member of the NK-class of homeodomain proteins, is expressed primarily in the adult prostate and has growth suppression and differentiating effects in prostate epithelial cells. METHODS: We performed immunohistochemical analysis for NKX3.1 and PSA expression in 4,061 samples included in a tissue microarray of a broad spectrum of human cancers and normal tissues. RESULTS: NKX3.1 expression was seen in prostate epithelial cells, prostate cancer, normal testis, 9% of primary and 5% of metastatic infiltrating ductal breast carcinoma, and 27% of primary and 26% of metastatic infiltrating lobular breast carcinoma. In a cohort of 474 primary breast cancers with median follow-up over 62.5 month survival, we found no effect of NKX3.1 expression on prognosis. NKX3.1 expression was more restricted than the spectrum of prostate specific antigen expression. CONCLUSIONS: Expression of NKX3.1 is highly restricted and is found primarily in benign and malignant prostatic epithelial cells and also in normal testis and lobular carcinoma of the breast.

Breast Neoplasms↗
PubMed2003

Tissue microarray analysis reveals prognostic significance of syndecan-1 expression in prostate cancer.

BACKGROUND: Tissue microarrays (TMA) have recently emerged as powerful tools to rapidly analyze the clinical significance of new molecular markers in human tumors. Here, we have tested several molecular markers on a prostate TMA containing 637 different specimens. METHODS: The specimens were from 551 patients with prostate cancer and long-term follow-up information on progression (median 5.3 years), tumor-specific and overall survival (median 5.9 years). Eighty-six specimens from benign prostatic hyperplasia were included as controls. Expression of Ki67, Bcl-2, p53, CD-10 (neutral endopeptidase), and syndecan-1 (CD-138) was analyzed by immunohistochemistry. RESULTS: Gleason grade and Ki67 Labeling Index (LI) were independent predictors of early recurrence and poor survival. Bcl-2 predicted early recurrence, whereas p53 was associated with poor survival. Syndecan-1 overexpression also predicted early recurrence and was significantly associated with tumor specific survival, high Gleason grade, Ki67 LI, and Bcl-2 overexpression. Neoadjuvant hormonal therapy was associated with overexpression of Bcl-2 and inhibition of Ki67 LI and CD-10, but did not affect the expression of the remaining markers. CONCLUSIONS: The results of this TMA study confirm a dominant prognostic significance of Gleason grading and Ki67 LI in prostate cancer, as compared to a less pronounced role of Bcl-2, and p53. We identified syndecan-1 as a new prognostic factor and provide evidence for an androgen-dependent regulation of CD-10 expression.

Aged↗
PubMed2002

DNA image cytometry and fluorescence in situ hybridization for noninvasive detection of urothelial tumors in voided urine.

BACKGROUND: Cystoscopy and histologic examination remain the standard methods for initial tumor diagnosis and monitoring for early detection of recurrences, since the sensitivity of conventional urinary cytology for the detection of urothelial tumors in urinary specimens is low. DNA image cytometry (ICM) and fluorescence in situ hybridization (FISH) have been suggested as ancillary tools. The goal of the current study was to compare the diagnostic value of DNA image cytometry and FISH for the noninvasive detection of urothelial tumors in voided urine. METHODS: Cytospin preparations were prepared from voided urine collected prior to the resection of 26 noninvasive (pTa) and 11 invasive (pT1-2) tumors. Specimens from 14 patients with benign prostatic hyperplasia were used as negative controls. DNA ICM was performed using the AUTOCYTE trade mark cell analytical system on Feulgen-stained cytospin specimens. The commercially available UroVysion trade mark FISH multiprobe was used to analyze chromosomes 3, 7, and 17, and 9p21. RESULTS: The overall sensitivity of cytology improved from 24% to 54% and to 78% if supplemented by ICM or FISH, respectively. Image cytometry detected all invasive tumors (pT1-2), while FISH missed one; FISH identified 19 of 26 (73%) pTa tumors, while only 9 (35%) of these tumors were aneuploid by ICM. The results of ICM and FISH were concordant in 37 of 51 (72%) cases. CONCLUSIONS: The current study shows that both FISH and ICM can successfully be used as supplementary methods to detect the clinically most relevant group of invasive bladder carcinomas. However, UroVysion FISH is more sensitive in the detection of pTa tumors than ICM, as it recognizes individual chromosomal alterations that frequently prevail in urothelial tumors.

Carcinoma, Transitional Cell↗
PubMed2002

A fluorescence in situ hybridization-based assay for improved detection of lung cancer cells in bronchial washing specimens.

BACKGROUND: Interphase fluorescence in situ hybridization (FISH) is a powerful tool for detecting chromosome and locus-specific changes in tumor cells. We developed a FISH-based assay to detect genetic changes in bronchial washing specimens of lung carcinoma patients. METHODS: The assay uses a mixture of fluorescently labeled probes to the centromeric region of chromosome 1 and to the 5p15, 8q24 (site of the c-myc gene), and 7p12 (site of the EGFR gene) loci to assess cells in bronchial washing specimens for chromosomal abnormalities indicative of lung carcinoma. The FISH assay was performed on 74 specimens that had been assessed previously for evidence of malignancy by routine cytology with Pap staining. RESULTS: Forty-eight patients had histologically confirmed lung carcinoma and 26 patients had a clinical diagnosis that was negative for lung carcinoma. FISH analysis was performed without knowledge of the patient's clinical information. The finding of six or more epithelial cells with gains of two or more chromosome regions was considered a positive FISH result (i.e., evidence of malignancy). The sensitivity of FISH for the detection of lung carcinoma was 82% in this set of specimens compared with a 54% sensitivity by design for cytology (FISH vs. cytology, P = 0.007). FISH detected 15 of 18 specimens that were falsely negative by cytology. The specificities of FISH and cytology were 82% and 100%, respectively, and were not significantly different (P = 0.993). CONCLUSIONS: The data indicate a potential utility of the FISH assay as an adjunct to bronchial washing cytology in routine clinical practice.

Adenocarcinoma↗
PubMed2002

Clinical validation of candidate genes associated with prostate cancer progression in the CWR22 model system using tissue microarrays.

To explore molecular mechanisms of prostate cancer progression, we applied tissue microarrays (TMAs) to analyze expression of candidate gene targets discovered by cDNA microarray analysis of the CWR22 xenograft model system. A TMA with 544 clinical specimens from different stages of disease progression was probed by mRNA in situ hybridization and protein immunohistochemistry. There was an excellent correlation (r = 0.96; n = 16) between the expression levels of the genes in the xenografts by cDNA microarray and mRNA in situ hybridization on a TMA. One of the most highly overexpressed genes in hormone-refractory CWR22R xenografts was the S100P gene. This gene, coding for a calcium signaling molecule implicated in the loss of senescence, was also significantly associated with progression in clinical tumors by TMA analysis (P < 0.001), suggesting dysregulation of this pathway in hormone-refractory and metastatic prostate cancers. Conversely, two genes that were down-regulated during tumor progression in the CWR22 model system were validated in vivo: crystallin mu (CRYM) and a LIM-domain protein LMO4 both showed significantly lower mRNA levels in hormone-refractory tumors as compared with primary tumors (P < 0.001). These results illustrate a strategy for rapid clinical validation at the mRNA and protein level of gene targets found to be differentially expressed in cDNA microarray experiments of model systems of cancer.

Animals↗
PubMed2002

Physical and transcript map of the hereditary prostate cancer region at xq27.

We have recently mapped a locus for hereditary prostate cancer (termed HPCX) to the long arm of the X chromosome (Xq25-q27) through a genome-wide linkage study. Here we report the construction of an approximately 9-Mb sequence-ready bacterial clone contig map of Xq26.3-q27.3. The contig was constructed by screening BAC/PAC libraries with markers spaced at approximately 85-kb intervals. We identified overlapping clones by end-sequencing framework clones to generate 407 new sequence-tagged sites, followed by PCR verification of overlaps. Contig assembly was based on clone restriction fingerprinting and the landmark information. We identified a minimal overlap contig for genomic sequencing, which has yielded 7.7 Mb of finished sequence and 1.5 Mb of draft sequence. The transcriptional mapping effort localized 57 known and predicted genes by database searching, STS content mapping, and sequencing, followed by sequence annotation. These transcriptional units represent candidate genes for HPCX and multiple other hereditary diseases at Xq26.3-q27.3.

Chromosome Mapping↗
PubMed2002

Morphological spot counting from stacked images for automated analysis of gene copy numbers by fluorescence in situ hybridization.

Fluorescence in situ hybridization (FISH) is a molecular diagnostic technique in which a fluorescent labeled probe hybridizes to a target nucleotide sequence of deoxyribose nucleic acid. Upon excitation, each chromosome containing the target sequence produces a fluorescent signal (spot). Because fluorescent spot counting is tedious and often subjective, automated digital algorithms to count spots are desirable. New technology provides a stack of images on multiple focal planes throughout a tissue sample. Multiple-focal-plane imaging helps overcome the biases and imprecision inherent in single-focal-plane methods. This paper proposes an algorithm for global spot counting in stacked three-dimensional slice FISH images without the necessity of nuclei segmentation. It is designed to work in complex backgrounds, when there are agglomerated nuclei, and in the presence of illumination gradients. It is based on the morphological top-hat transform, which locates intensity spikes on irregular backgrounds. After finding signals in the slice images, the algorithm groups these together to form three-dimensional spots. Filters are employed to separate legitimate spots from fluorescent noise. The algorithm is set in a comprehensive toolbox that provides visualization and analytic facilities. It includes simulation software that allows examination of algorithm performance for various image and algorithm parameter settings, including signal size, signal density, and the number of slices.

Algorithms↗
PubMed2002

Basal activation of transcription factor signal transducer and activator of transcription (Stat5) in nonpregnant mouse and human breast epithelium.

Transcription factor Stat5 (signal transducer and activator of transcription) is essential for PRL-induced terminal differentiation of mouse mammary epithelial cells during pregnancy and lactation and has been implicated in mammary tumorigenesis. A new and sensitive immunological method to detect active, tyrosine phosphorylated Stat5 in situ revealed that Stat5 is continuously activated in luminal epithelial cells of mouse and human breast, not only during pregnancy and lactation, but also outside of pregnancy. Examination of virgin Stat5a or Stat5b null mice suggested that Stat5a was the primary isoform activated in mammary epithelial cells. Basal activation of Stat5 in mammary epithelium of virgin wild-type mice was continuous throughout estrous cycle and was also detected in 17 of 17 normal human breast tissue specimens analyzed. PRL was identified as the principal factor maintaining basal activation of Stat5 in mammary epithelium of nonpregnant mice based on several lines of evidence. First, administration of PRL, but not GH or epidermal growth factor, uniformly enhanced basal activation of Stat5 in luminal mammary epithelial cells. Second, hypophysectomy disrupted basal activation of Stat5, an effect that was completely reversed by administration of PRL, but only partially by GH. Third, knock-out of the PRL receptor gene markedly reduced basal activation of Stat5, an effect that was maintained in a normalized endocrine environment after transplanting PRL receptor null mammary epithelium into wild-type mice. Continuous activation of Stat5 indicates a role of this transcription factor in normal, nonpregnant breast epithelial cells, and may shed new light on Stat5 involvement in breast tumor promotion.

Animals↗
PubMedDate not supplied

Expression of Bcl-2 family member Bid in normal and malignant tissues.

Bid is the only known Bcl-2 family member that can function as an agonist of proapoptotic Bcl-2-related proteins such as Bax and Bak. Expression of the proapoptotic Bcl-2 family protein Bid was assessed by immunoblotting and immunohistochemical methods in normal murine and human tissues, and in several types of human cancers and tumor cell lines. Bid expression in normal tissues varied widely, with prominent Bid immunostaining occurring in several types of short-lived cells (e.g., germinal center B cells, peripheral blood granulocytes, differentiated keratinocytes) and in apoptosis-sensitive cells (e.g., adult neurons). Analysis of Bid expression by immunostaining of 100 colon, 95 ovarian, and 254 prostate cancers, as well as 59 brain tumors and 50 lymphomas, revealed evidence of altered Bid regulation in some types of cancers. Correlations with clinical outcome data revealed association of higher levels of Bid with longer recurrence-free survival in men with locally advanced (T3 stage) prostate cancer (P=0.04). Immunoblot analysis of Bid protein levels in the NCI's panel of 60 human tumor cell lines revealed a correlation between higher levels of Bid and sensitivity to ribonucleotide reductase (RR)-inhibiting drugs (P<0.0005). Overexpression of Bid in a model tumor cell line by gene transfection resulted in increased sensitivity to apoptosis induction by a RR inhibitor. Taken together, these observations suggest a potential role for Bid in tumor responses to specific chemotherapeutic drugs, and lay a foundation for future investigations of this member of the Bcl-2 family in healthy and diseased tissues.

Animals↗