Analytical Cellular Pathology - Volume 21, issue 2

Authors: Giaretti, Walter | Macciocu, Barbara | Geido, Elio | Hermsen, Mario A.J.A. | Postma, Cindy | Baak, Jan P.A. | Williams, Richard A. | Meijer, Gerrit A.

Article Type: Research Article

Abstract: The molecular pathways and the timing of genetic events during human colorectal carcinogenesis are still not fully understood. We have addressed the intratumor heterogeneity of the mutational status of the k‐ras oncogene and of the p53 oncosuppressor gene during the adenoma–carcinoma sequence by investigating 26 human colorectal adenomas containing early cancer. An intratumor comparative analysis was obtained among the adenomatous and carcinomatous component pairs. Additionally, we have analyzed 17 adenomas having cancer in the near vicinity. The adenomatous components of the adenomas containing early cancer and the adenomas having cancer in the near vicinity had comparable frequencies for k‐ras …mutations (28 and 47%) but different for p53 mutations (52 and 7%, p‐value = 0.01). Interestingly, the adenomatous and carcinomatous components of the adenomas containing early cancer were rarely heterogeneous for the k‐ras mutational status (only in 13% of the cases) but were characterized by heterogeneity of the p53 status in 59% of the cases (p‐value < 0.01). In addition, the mutations of p53 for the adenomatous components of the adenomas containing early cancer were statistically significantly associated with severe dysplasia (p‐value = 0.01). Intratumor homogeneity of k‐ras status during the human colorectal adenoma–carcinoma sequence suggests that the role of k‐ras is more related to tumor initiation than to tumor progression. On the contrary, intratumor heterogeneity of p53 mutations indicates that the type of the p53 mutations may also be relevant for selection and expansion of new subclones leading to tumor progression. Show more

Keywords: Oncogenes, tumor suppressor genes, colorectal tumor progression, molecular biology

Citation: Analytical Cellular Pathology, vol. 21, no. 2, pp. 49-57, 2000

Authors: Sudbø, J. | Marcelpoil, R. | Reith, A.

Article Type: Research Article

Abstract: Graph theory based methods represent one approach to an objective and reproducible structural analysis of tissue architecture. By these methods, neighborhood relations between a number of objects (e.g., cells) are explored and inherent to these methods are therefore certain requirements as to the number of objects to be included in the analysis. However, the question of how many objects are required to achieve reproducible values in repeated computations of proposed structural features, has previously not been adressed specifically. After digitising HE stained slides and storing them as grey level images, cell nuclei were segmented and their geometrical centre of …gravity were computed, serving as the basis for construction of the Voronoi diagram (VD) and its subgraphs. Variations in repeated computations of structural features derived from these graphs were related to the number of cell nuclei included in the analysis. We demonstrate a large variation in the values of the structural features from one computation to another in one and the same section when only a limited number of cells (100–500) are included in the analysis. This variation decreased with increasing number of cells analyzed. The exact number of cells required to achieve reproducible values differ significantly between tissues, but not between separate cases of similar lesions. There are no significant differences between normal and malignantly changed tissues in oral mucosa with respect to how many cells must be included. For graph theory based analysis of tissue architecture, care must be taken to include an adequate number of objects; for some of the structural features we have tested, more than 3000 cells. Show more

Keywords: Graph theory, caveats, reproducibility, numerical requirements

Citation: Analytical Cellular Pathology, vol. 21, no. 2, pp. 59-69, 2000

Authors: Sudbø, J. | Marcelpoil, R. | Reith, A.

Article Type: Research Article

Abstract: An adequate reproducibility in the description of tissue architecture is still a challenge to diagnostic pathology, sometimes with unfortunate prognostic implications. To assess a possible diagnostic and prognostic value of quantitiative tissue architecture analysis, structural features based on the Voronoi Diagram (VD) and its subgraphs were developed and tested. A series of 27 structural features were developed and tested in a pilot study of 30 cases of prostate cancer, 10 cases of cervical carcinomas, 8 cases of tongue cancer and 8 cases of normal oral mucosa. Grey level images were acquired from hematoxyline‐eosine (HE) stained sections by a charge …coupled device (CCD) camera mounted on a microscope connected to a personal computer (PC) with an image array processor. From the grey level images obtained, cell nuclei were automatically segmented and the geometrical centres of cell nuclei were computed. The resulting 2‐dimensional (2D) swarm of pointlike seeds distributed in a flat plane was the basis for construction of the VD and its subgraphs. From the polygons, triangulations and arborizations thus obtained, 27 structural features were computed as numerical values. Comparison of groups (normal vs. cancerous oral mucosa, cervical and prostate carcinomas with good and poor prognosis) with regard to distribution in the values of the structural features was performed with Student's t‐test. We demonstrate that some of the structural features developed are able to distinguish structurally between normal and cancerous oral mucosa (P=0.001), and between good and poor outcome groups in prostatic (P=0.001) and cervical carcinomas (P=0.001). We present results confirming previous findings that graph theory based algorithms are useful tools for describing tis‐ sue architecture (e.g., normal versus malignant). The present study also indicates that these methods have a potential for prognostication in malignant epithelial lesions. Show more

Keywords: Graph theory, Voronoi Diagram, diagnostic pathology, prognostication tissue architecture, reproducibility, oral mucosa, oral carcinoma, carcinoma of the cervix, carcinoma of the prostate

Citation: Analytical Cellular Pathology, vol. 21, no. 2, pp. 71-86, 2000

Authors: Risio, Mauro | Sarotto, Ivana | Rossini, Francesco Paolo | Newmark, Harold | Yang, Kan | Lipkin, Martin

Article Type: Research Article

Abstract: Western‐style diets (WDs) trigger and sustain the early phases of tumorigenesis in mouse colon, and when continued throughout the life span lead to the development of dysplastic crypts. In order to evaluate the roles both of cell proliferation and programmed cell death (PCD) in WD‐induced tumorigenesis, immunohistochemical detection of proliferating nuclear antigen (PCNA), in situ end labeling (TUNEL) of DNA breaks, and p53 protein were carried out in mouse colonic mucosa during prolonged feeding of two WDs. PCNA Labeling Index of colonic crypts was significantly higher in WD‐treated animals than in controls only at the beginning of the nutritional study, …the gap rapidly bridged by increased cell proliferation spontaneously occurring in the colonic mucosa during aging. A transient early homeostatic activation of PCD at the base of the crypt also was observed in WD groups. No changes in PCD were seen in the upper third of the crypt or in surface epithelium throughout the study, indicating that PCD in that colonic crypt segment produces a constant flux of cell loss, uninfluenced by homeostatic fluctuations. A major finding was an irreversible, progressive, age‐related decline of PCD at the crypt base in both control and treated animals that occurred during the second half of the rodents' life span. p53 protein was not immunohistochemically detected, suggesting that neither overexpression of wild‐type nor mutated forms of the protein are involved in the above mentioned changes. Show more

Keywords: Colon, carcinogenesis, cell proliferation, diet, programmed cell death

Citation: Analytical Cellular Pathology, vol. 21, no. 2, pp. 87-94, 2000