Analytical Cellular Pathology - Volume 27, issue 5-6

Authors: Meijer, Gerrit A.

Article Type: Other

Citation: Analytical Cellular Pathology, vol. 27, no. 5-6, pp. 273-275, 2005

Authors: Baak, Jan P.A. | Kruse, Arnold-Jan | Janssen, Emiel | van Diermen, Bianca

Article Type: Research Article

Citation: Analytical Cellular Pathology, vol. 27, no. 5-6, pp. 277-280, 2005

Authors: Fijneman, Remond J.A.

Article Type: Research Article

Abstract: Predisposition to non-familial, sporadic cancer is strongly influenced by multiple tumor susceptibility genes (TSGs), each with apparently minor effects on the cancer phenotype. Sequence analysis of the human genome has yielded numerous single nucleotide polymorphisms (SNPs), raising the expectation that new low-penetrance TSGs will be identified that can be used to estimate an individuals cancer risk. However, mouse models for human cancer showed that the effects of many low-penetrance TSGs are highly variable due to their involvement in epistatic interactions. Together, these interacting TSGs form large molecular networks, which represent cancer-associated biological modules that influence the tumorigenic process. As a …consequence, although allelic variation in one TSG on a permissive genetic background can have major effects on tumor development, the net effect of allelic variation in multiple interacting TSGs remains hard to predict. Therefore, the predictive value of SNP-analysis to estimate an individuals cancer risk will be restricted to those TSGs that exhibit single-gene effects. New strategies need to be developed to evaluate cancer risk associated with biological modules that are influenced by TSG-networks. Show more

Keywords: Genetic predisposition, tumor susceptibility genes, epistasis, sporadic cancer, mouse

Citation: Analytical Cellular Pathology, vol. 27, no. 5-6, pp. 281-292, 2005

Authors: Duesberg, Peter | Li, Ruhong | Fabarius, Alice | Hehlmann, Ruediger

Article Type: Research Article

Abstract: Conventional genetic theories have failed to explain why cancer (1) is not heritable and thus extremely rare in newborns, (2) is caused by non-mutagenic carcinogens, (3) develops only years to decades after initiation by carcinogens, (4) follows pre-neoplastic aneuploidy, (5) is aneuploid, (6) is chromosomally and phenotypically “unstable”, (7) carries specific aneusomies, (8) generates much more complex phenotypes than conventional mutation such as multidrug resistance, (9) generates nonselective phenotypes such as metastasis (no benefit at native site) and “immortality” (not necessary for tumorigenesis), and (10) does not contain carcinogenic mutations. We propose, instead, that cancer is a chromosomal disease. Accordingly …carcinogenesis is initiated by random aneuploidies, which are induced by carcinogens or spontaneously. Since aneuploidy unbalances 1000s of genes, it corrupts teams of proteins that segregate, synthesize and repair chromosomes. Aneuploidy is therefore a steady source of chromosomal variations from which, in classical Darwinian terms, selection encourages the evolution and malignant progression of cancer cells. The rates of specific chromosomal variations can exceed conventional mutations by 4–11 orders of magnitude, depending on the degrees of aneuploidy. Based on their chromosomal constitution cancer cells are new cell “species” with specific aneusomies, but unstable karyotypes. The cancer-specific aneusomies generate complex, malignant phenotypes through the abnormal dosages of 1000s of genes, just as trisomy 21 generates Down syndrome. In sum, cancer is caused by chromosomal disorganization, which increases karyotypic entropy. Thus, cancer is a chromosomal rather than a genetic disease. The chromosomal theory explains (1) non-heritable cancer because aneuploidy is not heritable, (2) non-mutagenic carcinogens as aneuploidogens, (3) long neoplastic latencies by the low probability of evolving new species, (4) nonselective phenotypes via genes hitchhiking with selective chromosomes, and (5) immortality because, through their cellular heterogeneity, cancers survive negative mutations and cytotoxic drugs via resistant subspecies. Show more

Citation: Analytical Cellular Pathology, vol. 27, no. 5-6, pp. 293-318, 2005

Authors: Reis, Rui M. | Martins, Albino | Ribeiro, Susana A. | Basto, Diana | Longatto-Filho, Adhemar | Schmitt, Fernando C. | Lopes, José M.

Article Type: Research Article

Abstract: Gliosarcomas are rare and poorly characterized malignant brain tumors that exhibit a biphasic tissue pattern with areas of gliomatous and sarcomatous differentiation. These tumors are histological variants of glioblastoma, displaying a similar genetic profile and dismal prognosis. Up-regulation of PDGFR subfamily of tyrosine kinase members, PDGFR-α and c-Kit, and their intracellular effectors RAS/RAF/MAPK has a crucial role in the cancer development. In addition, signal transduction mediated by activating mutations of c-Kit and PDGFR can be effectively blocked by specific tyrosine kinase inhibitors, such as Imatinib mesylate. The aim of this study was to characterize the molecular alterations of PDGFR signaling …in gliosarcomas. Six cases were analyzed by immunohistochemistry for the expression of PDGFR-α, c-Kit and their ligands PDGF-A and SCF, respectively. The cases were further evaluated for the presence of activating mutations of PDGFR-α (exons 12 and 18) and c-kit (exons 9, 11, 13, and 17), as well as B-RAF (exons 11 and 15). Expression of PDGF-A was found in all cases and co-expression of PDGFR-α was observed in three cases. Four cases showed expression of SCF, and c-Kit was observed only in one case that also expressed SCF. Generally, immunoreaction predominates in the glial component. The mutational analysis of PDGFR-α showed the presence of an IVS17-50insT intronic insertion in two cases, one of them also with a 2472C > T silent mutation; this silent mutation was also found in another case. Glioma cell line analysis of IVS17-50insT insertion showed no influence on PDGFR-α gene splicing. No mutations were detected in c-kit and B-RAF oncogenes. Our results indicate that activating mutations of PDGFR-α, c-kit and B-RAF are absent in gliosarcomas. Nevertheless, the presence of a PDGFR-a/PDGFA and c-Kit/SCF autocrine/paracrine stimulation loop in a proportion of cases, supports the potential role of specific tyrosine kinase inhibitors in the treatment of gliosarcomas. Show more

Keywords: Gliosarcoma, PDGFR-α, PDGF-A, c-Kit, SCF, BRAF

Citation: Analytical Cellular Pathology, vol. 27, no. 5-6, pp. 319-326, 2005

Authors: Chaudhuri, Jyoti P. | Kasprzycki, Eva | Battaglia, Mathew | McGill, John R. | Brøgger, Anton | Walther, Joachim-U. | Reith, Albrecht

Article Type: Research Article

Abstract: Background and aim: One of the two parental allelic genes may selectively be expressed, regulated by imprinting, X-inactivation or by other less known mechanisms. This study aims to reflect on such genetic mechanisms. Materials and methods: Slides from short term cultures or direct smears of blood, bone marrow and amniotic fluids were hybridized with FISH probes singly, combined or sequentially. Two to three hundred cells were examined from each preparation. Results and significance: A small number of cells (up to about 5%), more frequent in leukemia cases, showed the twin features: (1) nuclei with biphasic chromatin, one part decondensed and …the other condensed; and (2) homologous FISH signals distributed equitably in those two regions. The biphasic chromatin structure with equitable distribution of the homologous FISH signals may correspond to the two sets of chromosomes, supporting observations on ploidywise intranuclear order. The decondensed chromatin may relate to enhanced transcriptions or advanced replications. Conclusions: Transcriptions of only one of the two parental genomes cause allelic exclusion. Genomes may switch with alternating monoallelic expression of biallelic genes as an efficient genetic mechanism. If genomes fail to switch, allelic exclusion may lead to malignancy. Similarly, a genome-wide monoallelic replication may tilt the balance of heterozygosity resulting in aneusomy, initiating early events in malignant transformation and in predicting cancer mortality. Show more

Keywords: Chromatin, intranuclear order, epigenetics and malignancy

Citation: Analytical Cellular Pathology, vol. 27, no. 5-6, pp. 327-334, 2005

Authors: Huisman, André | Ploeger, Lennert S. | Dullens, Hub F.J. | Poulin, Neal | Grizzle, William E. | van Diest, Paul J.

Article Type: Research Article

Abstract: Introduction: Analysis of nuclear texture features as a measure of nuclear chromatin changes has been proven to be useful when measured on thin (5–6 μm) tissue sections using conventional 2D bright field microscopy. The drawback of this approach is that most nuclei are not intact because of those thin sections. Confocal laser scanning microscopy (CLSM) allows measurements of texture in 3D reconstructed nuclei. The aim of this study was to develop 3D texture features that quantitatively describe changes in chromatin architecture associated with malignancy using CLSM images. Methods: Thirty-five features thoughtfully chosen from 4 categories of 3D texture features (discrete …texture features, Markovian features, fractal features, grey value distribution features) were selected and tested for invariance properties (rotation and scaling) using artificial images with a known grey value distribution. The discriminative power of the 3D texture features was tested on artificially constructed benign and malignant 3D nuclei with increasing nucleolar size and advancing chromatin margination towards the periphery of the nucleus. As a clinical proof of principle, the discriminative power of the texture features was assessed on 10 benign and 10 malignant human prostate nuclei, evaluating also whether there was more texture information in 3D whole nuclei compared to a single 2D plane from the middle of the nucleus. Results: All texture features showed the expected invariance properties. Almost all features were sensitive to variations in the nucleolar size and to the degree of margination of chromatin. Fourteen texture features from different categories had high discriminative power for separating the benign and malignant nuclei. The discrete texture features performed less than expected. There was more information on nuclear texture in 3D than in 2D. Conclusion: A set of 35 3D nuclear texture features was used successfully to assess nuclear chromatin patterns in 3D images obtained by confocal laser scanning microscopy, and as a proof of principle we showed that these features may be clinically useful for analysis of prostate neoplasia. Show more

Keywords: Confocal laser scanning microscopy, 3D, texture features, image analysis, prostate cancer, nuclear chromatin

Citation: Analytical Cellular Pathology, vol. 27, no. 5-6, pp. 335-345, 2005

Authors: Volpi, Annalisa | Bravaccini, Sara | Medri, Laura | Cerasoli, Serenella | Gaudio, Michele | Amadori, Dino

Article Type: Research Article

Abstract: Objective: Recent years have seen a considerable wealth of studies conducted on the potential usefulness of telomerase determination in diagnosis, prognosis and targeted cancer therapy. The frequently used Telomeric Repeat Amplification Protocol assay suffers from some drawbacks, the most important being the rate of false positives. In situ analysis using well characterised antibodies directed against the human telomerase reverse transcriptase (hTERT) would therefore appear to be important to morphologically identify the nature of telomerase positive cells. Methods: We performed immunostaining in a series of cultured cells and in normal, preneoplastic and tumour tissues from different organs using a monoclonal antibody …directed against the catalytic subunit of telomerase. Results: Immunoreactivity was not observed in perennial cells of terminally differentiated cardiac and skeletal muscular tissues or in small pyramidal cells of the cerebral cortex. Conversely, it was found in other normal somatic tissues as well as in precancerous lesions and in all tumour histotypes. Conclusions: Immunohistochemistry with a well characterised hTERT-specific monoclonal antibody permitted the identification of hTERT immunopositive cells in normal somatic tissues. Whether hTERT protein detected by immunostaining with hTERT-specific Tel 3 36-10 antibody is actually the degraded form of the protein that retains hTERT antigenicity but not enzymatic function, or whether it represents the real, potentially functional catalytic subunit of the enzyme, immunohistochemistry would not seem to represent a useful tool to investigate the role of telomerase and the mechanisms involved in its regulation. Show more

Keywords: hTERT immunohistochemical expression, normal and tumour tissue, telomerase

Citation: Analytical Cellular Pathology, vol. 27, no. 5-6, pp. 347-353, 2005

Authors: Silvestrini, Rosella

Article Type: Other

Citation: Analytical Cellular Pathology, vol. 27, no. 5-6, pp. 355-355, 2005

Authors: Baak, Jan P.A. | Kruse, Arnold-Jan | Janssen, Emiel | van Diermen, Bianca

Article Type: Other

Citation: Analytical Cellular Pathology, vol. 27, no. 5-6, pp. 357-357, 2005