Influence of epidermal growth factor and gastrin on the cell proliferation of human meningiomas versus astrocytic tumors maintained as ex vivo tissue cultures

The hormone sensitivity of a tumor is traditionally based on the presence of steroid receptors. Other factors should be taken into consideration. Here, we studied the influence of 10 nM epidermal growth factor (EGF) or gastrin on the proliferation of human ex vivo tumor cultures by means of [3H]thymidine autoradiography. The immunohistochemical EGF-receptor expression was also quantified by means of computer-assisted microscopy. The results demonstrated that the proliferation of 6/11 astrocytic tumors and 3/16 meningiomas was sensitive to at least one factor tested, i.e. EGF or gastrin (P < 0.01), and 5 of these 9 'hormone-sensitive' tumors were sensitive to both factors. The immunohistochemical labeling index for the EGF receptor was higher than 80% in 15/16 meningiomas, but only in 6/11 gliomas (P < 0.01). These results suggest that EGF and gastrin are important for astrocytic tumor proliferation and significantly (P < 0.01) less important for meningiomas. Thus, astrocytic tumors may be steroid insensitive in term of cell growth, but are certainly not hormone insensitive.

Quantitative chromatin pattern description in Feulgen-stained nuclei as a diagnostic tool to characterize the oligodendroglial and astroglial components in mixed oligo-astrocytomas

The oligoastrocytoma, as a mixed glioma, represents a nosologic dilemma with respect to precisely defining the oligodendroglial and astroglial phenotypes that constitute the neoplastic cell lineages of these tumors. In this study, cell image analysis with Feulgen-stained nuclei was used to distinguish between oligodendroglial and astrocytic phenotypes in oligodendrogliomas and astrocytomas and then applied to mixed oligoastrocytomas. Quantitative features with respect to chromatin pattern (30 variables) and DNA ploidy (8 variables) were evaluated on Feulgen-stained nuclei in a series of 71 gliomas using computer-assisted microscopy. These included 32 oligodendrogliomas (OLG group: 24 grade II and 8 grade III tumors according to the WHO classification), 32 astrocytomas (AST group: 13 grade II and 19 grade III tumors), and 7 oligoastrocytomas (OLGAST group). Initially, image analysis with multivariate statistical analyses (Discriminant Analysis) could identify each glial tumor group. Highly significant statistical differences were obtained distinguishing the morphonuclear features of oligodendrogliomas from those of astrocytomas, regardless of their histological grade. When compared with the 7 mixed oligoastrocytomas under study, 5 exhibited DNA ploidy and chromatin pattern characteristics similar to grade II oligodendrogliomas, I to grade III oligodendrogliomas, and I to grade II astrocytomas. Using multifactorial statistical analyses (Discriminant Analysis combined with Principal Component Analysis). It was possible to quantify the proportion of "typical" glial cell phenotypes that compose grade II and III oligodendrogliomas and grade II and III astrocytomas in each mixed glioma. Cytometric image analysis may be an important adjunct to routine histopathology for the reproducible identification of neoplasms containing a mixture of oligodendroglial and astrocytic phenotypes.

Dynamic characterization of glioblastoma cell motility

The cell motility dynamic of two glioblastoma cell lines (U373 and U87) was studied by means of an automatic video-cell-tracking-system enabling each cell in a colony to be tracked for several hours. Twenty-five experiments were performed on both models growing on three different supports (glass, plastic and Matrigel). Cell motility was significantly different in each cell line and also for different growth support in a given cell line. We observed that U87 cells are significantly (p < 0.00001) less motile than U373 cells. The most favorable growth supports for cell motility studies were Matrigel and glass. A significant (p < 0.001) correlation between cell colony density and cell motility was highlighted, with isolated cells exhibiting a motility level distinct from the one observed for colonies. The present methodology, which enabled cell motility to be quantified in human glioblastoma cells, represents an original tool for identifying new classes of compounds able to reduce glioblastoma cell motility and cell migration potential into the brain.

The combined determination of proliferative activity and cell density in the prognosis of adult patients with supratentorial high-grade astrocytic tumors

Tumor growth represents the ratio between cell gain (number of mitoses per unit of time, i.e., proliferative activity) and cell loss (number of cell deaths during the same unit of time). While in adults, proliferative activity parallels the level of malignancy in astrocytic tumors and therefore represents a useful diagnostic marker, cell loss has never been concomitantly assessed in tumors of this type. We hypothesize that cell density assessable on histologic slides represents the ratio between cell gain and cell loss. This hypothesis concerns only the diffuse type of astrocytic tumors. Proliferative activity (assessed by MIB1 antigen immunostain) and cell density were thus quantitatively assessed by means of a cell image processor in a series of 54 supratentorial astrocytic tumors of adult patients, which included 15 astrocytomas (ASTs), 18 anaplastic astrocytomas (ANAs), and 21 glioblastomas (GBMs). The results show that proliferative activity and cell density were highly correlated (P = .003) and that both correlated with histopathologic grade. The patients with a high-grade astrocytic tumor (i.e., ANA or GBM) that exhibited a low level of proliferative activity but high cell density survived for significantly shorter periods than did patients with a tumor that exhibited low proliferative activity and low cell density (P = .002). The patients with a high-grade astrocytic tumor that exhibited high proliferative activity and high cell density survived for significantly less time than did the patients with a tumor that exhibited high proliferative activity but low cell density (P < .05). A marked difference in survival periods was observed between the patients with a high-grade astrocytic tumor that exhibited a low level of proliferative activity and low cell density and the patients with a tumor that exhibited a high level of proliferative activity and high cell density (P < .001). The concomitant determination of proliferative activity and cell density seems likely to enable determination of the few adult patients who have high-grade astrocytic tumors and who will survive for a considerable period (several years).

Nearest-neighbor classification for identification of aggressive versus nonaggressive low-grade astrocytic tumors by means of image cytometry-generated variables

The authors investigated whether cytometry-related variables generated by means of computer-assisted microscopic analysis of Feulgen-stained nuclei can contribute significant information toward the characterization of low-grade astrocytic tumor aggressiveness. This investigation was conducted using the nearest-neighbor rule (a traditional classification method used in pattern recognition) to analyze a series of 250 supratentorial astrocytic tumors from adult patients. This series included 39 low-grade astrocytomas and 211 high-grade astrocytic tumors (including 47 anaplastic astrocytomas and 164 glioblastomas multiforme [GBMs]). The results show that the 3-nearest-neighbors rule enabled a subgroup of "atypical" astrocytomas to be distinguished from the "typical" tumors. The atypical astrocytoma species exhibited a DNA content (DNA ploidy level) and morphonuclear characteristics that were statistically more similar to the characteristics of GBMs than to those exhibited by the typical astrocytomas. An analysis of survival data revealed that patients with atypical astrocytomas survived for a significantly shorter period (p < 0.001) than patients with typical lesions of this kind. In fact, patients with atypical astrocytomas had a survival period similar to that of patients with anaplastic astrocytomas, whereas patients with typical astrocytomas had a survival period significantly longer (p < 0.0001) than those associated with anaplastic astrocytomas and GBMs.

In vitro influence of Phaseolus vulgaris, Griffonia simplicifolia, concanavalin A, wheat germ, and peanut agglutinins on HCT-15, LoVo, and SW837 human colorectal cancer cell growth

BACKGROUND/AIMS

Compared with normal colonic mucosa, lectin receptor expression is increased in hyperplastic and neoplastic tissues; some lectins have been shown to influence human colonic epithelial cell proliferation. The aim was to assess further the influence of five lectins (Phaseolus vulgaris (PNA), Griffonia simplicifolia (GSA), concanavalin A (Con A), wheat germ (WGA), and peanut (PHA-L) agglutinins) on cellular growth in three human colorectal cancer cell lines (LoVo, HCT-15 and SW837).

METHODS

Cells were cultured in four lectin concentrations (0.1, 1.0, 10, and 100 micrograms/ml) and growth assessed at days 2, 3, 5, and 7. The experiments were performed in media supplemented with either 1% or 10% fetal calf serum (FCS). Growth was assessed using the MTT (3-(4,5)-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) colorimetric assay.

RESULTS

Growth in each cell line was greatly affected by at least two of the lectins tested. There was some variation in the effect of a given lectin on different cell lines. Lectin effects showed a dose-response and the greatest effects generally resulted from the highest concentrations at the longest culture time. WGA and Con A induced large effects in all cell lines; the effects of Con A were partly blocked by the higher concentration of FCS. PNA had modest and uniform stimulatory effects overall. The effects of GSA and PHA-L varied between cell lines.

CONCLUSIONS

The lectins studied all have the potential to affect colonic cancer growth in vitro. Many dietary lectins are resistant to digestion and may have important effects in vitro but the definition of their role in human colonic cancer biology must take into account the variability in lectin response.

The influence of gastrin and/or cholecystokinin antagonists on the proliferation of three human astrocytic tumor cell lines

We have investigated the potential role of gastrin in the regulation of cell growth in human astrocytic tumors. To this end we have used synthetic analogs of gastrin and cholecystokinin (CCK) which behave as gastrin and/or CCK antagonists, e.g. compounds JMV-97, JMV-209 and JMV-179. Their effects on astrocytic tumor cell proliferation was investigated by the use of the colorimetric MTT assay. The in vitro biological models used in the present study included the SW1088, U87 and U373 astrocytic tumor cell lines. The results demonstrated marked influence of gastrin and CCK antagonists in the regulation of astrocytic tumor growth. This suggests that gastrin and/or CCK antagonists might be tested in experimental glioblastoma.

VIP and pituitary adenylate cyclase activating polypeptide (PACAP) have an antiproliferative effect on the T98G human glioblastoma cell line through interaction with VIP2 receptor

Functional VIP/PACAP receptors were identified in the human glioblastoma cell line T98G, based on the relative potency of VIP, PACAP and PACAP-38 to stimulate adenylate cyclase activity. Analysis of the T98G cells mRNA by reverse transcription followed by a polymerase chain reaction (RT-PCR) demonstrated the expression of the mRNA coding for the VIP2 receptor subclass only. VIP, PACAP-27 and PACAP-38 were potent and efficIent inhibitors of cell proliferation, assessed by the colorimetric MTT assay. VIP, PACAP-27 and PACAP-38 also reduced the incorporation of 3H-thymidine in T98G cells, but did not significantly alter the percentage of cells present at each stage of the cell cycle. Thus, VIP and PACAP, probably acting through a VIP2 receptor subtype, decreased cell proliferation.

Influence of culture media and multidrug resistance on the wheat germ agglutinin (WGA) glycocytochemical expression of two human glioblastoma cell lines

Over the last two decades, many studies carried out with the aid of lectins have firmly established that cell glycans usually change in the course of the normal processes of growth and development, as well as in pathological situations. We describe here the in vivo binding expression of wheat germ agglutinin (WGA) to the U87 and U373 human glioblastoma cell lines exposed to various culture media i.e., media supplemented with either 10% (FCS10) or 1% (FCS1) fetal calf serum with or without 10 n Mol/l 17 beta-oestradiol (E2). After exposure to chemotherapeutic agents, the resistant variants (CR) developed by the two cell lines were also investigated. The quantitative cytochemical assessment of WGA binding was assessed by means of a cell image processor, which was also used to determine ploidy level (on Feulgen-stained nuclei) by means of DNA histogram typing (DHT). Our results clearly demonstrate that when U373 cells are cultured with E2, this steroid can modify the expression of WGA binding, whereas U87 cells were unaffected. Similarly, lowering the FCS level enhanced the WGA binding of the U373 cell line. Multidrug-resistant cell variants were associated with both aneuploidy and a dramatic decrease in cytochemical WGA expression.

Methodological aspects of using decision trees to characterise leiomyomatous tumors

The aim of the present work is to present the potential uses of a classification technique labeled the "decision tree" for tumor characterisation when faced with a large number of features. The decision tree technique enables multifeature logical classification rules to be produced by determining discriminatory values for each feature selected. In this report, we propose a methodology that used decision trees to compare and evaluate the information contributed by different types of features for tumor characterisation. This methodology is able to produce a set of hypotheses related to a diagnosis and or prognosis problem. For example, hypotheses can be producted (on the basis of a set of descriptive features) to explain why tumor cases belong to a given histopathological group. To illustrate our purpose, this methodology was applied to the difficult problem of leiomyomatous tumour diagnosis. The aim was to illustrate what kind of diagnostic information can be extracted from a sample data set including 23 smooth muscle tumors (14 benign leiomyomas and 9 malignant leiomyosarcomas) described by a large set of computer-assisted, microscope-generated features. Three groups of features were used relating to: (1) ploidy level determination (10 features), (2) quantitative chromatin pattern description (15 features), and (3) immunohistochemically related antigen specificities (6 features). All these features were quantified by digital cell image analysis. The results suggest that an objective distinction between leiomyomas and leiomyosarcomas can be established by means of simple logical rules depending on only a few features among which the immunohistochemically revealed antigen expression of desmin plays a preponderant part. One of the combinations of features proposed by the methodology is interesting for pathologists, because it includes two features describing the appearance of a nucleus in terms of chromatin distribution homogeneity and density, two features widely used by pathologists in tumor-grading systems.

Influence of gastrin on human astrocytic tumor cell proliferation

BACKGROUND

Gastrin and cholecystokinin (CCK) mediate their effects through at least two types of receptors (CCK receptors A and B). While it has been hypothesized that gastrin, a stimulator of gastric acid secretion, is also a neurotransmitter and a stimulator of cell proliferation in various normal and neoplastic tissues, its effect on astrocytic brain tumors has not been actively investigated.

PURPOSE

Our goal was to determine the effects of gastrin and gastin and/or CCK antagonists on the proliferation in vitro of astrocytic tumor cells by use of both established cell lines and primary cell cultures of tumor tissue.

METHODS

Ten established astrocytic tumor cell lines, SW1088, SW1783, Hs683, H4, U87, U118, U138, U373, T98G, and A172, were studied. The effects of added gastrin (at 0.01, 0.1, and microM) and the gastrin/CCK antagonists L-365,260, CI-988, L-364,718, and JMV 234 (each at 0.01, 0.1, and 1 microM) on the cellular proliferation rates of the 10 cell lines were indirectly measured by use of the colorimetric tetrazolium assay. The influence of gastrin (at 0.01 microM) on the cellular proliferation of primary cultures from nine freshly explanted astrocytic tumors was assessed by means of tritiated thymidine uptake and autoradiography.

RESULTS

At specific concentrations, added gastrin increased the cellular proliferation of three established astrocytic cell lines (A172, Hs683, and SW1088), decreased it in two (U373 and T98G), and was without effect on the remaining five. Gastrin decreased cellular proliferation in one primary astrocytic tumor cell culture, stimulated it in five, and had no apparent effect in the remaining three. L-365,260, a CCK receptor B antagonist used at 0.01 microM, increased cellular proliferation in seven cell lines (A172, H4, Hs683, SW1783, T98G, U118, and U138), decreased it in one (U87), and had no effect in the remaining two. CI-988, another CCK receptor B antagonist used at 0.01 microM, inhibited cellular proliferation in five cell lines (A172, H4, SW1783, U373, and U87), stimulated it in two (T98G and U138), and had no effect in three. The CCK receptor A antagonists L-364,718 and JMV 234, both used at 0.01 microM, affected the cellular proliferation of only three of the 10 cell lines.

CONCLUSIONS

These results suggest that gastrin (and perhaps CCK that belongs to the same peptide family) may play a role in the growth of a substantial proportion of human astrocytic tumors.

Computer-assisted microscope characterization of BCNU-induced modifications in the collective behavior of 12 human brain cancer cell lines

The aim of our study is to characterize the disturbance induced by repeated BCNU treatments in 12 human brain tumor cell lines in terms of their collective behavior. This collective behavior was characterized by means of the Delaunay triangulation and Voronoi mathematical paving techniques combined with the computer-assisted microscope analysis of Feulgen-stained nuclei. This methodology enabled growth to be characterized in terms of cell colony size and density. In addition to this colony pattern characterization, the DNA ploidy level was assessed by means of DNA histogram typing. The cell proliferation level was also determined. Ten astrocytic and two medulloblastoma cell lines treated weekly with BCNU were analyzed. Study of the cell colony architecture and cell proliferation revealed specific BCNU-induced modifications in connection with the origins of the cell lines, i.e. astrocytoma (AST), glioblastoma (GBM), or medulloblastoma (MED). The BCNU-induced effect on GBM (the more malignant of the cell lines) was very different in that proliferation was weakened, but the cell colony density increased after a latency phase. The decrease in cell colony density and cell proliferation of MED seems to indicate that they are more sensitive to BCNU than GBM, but relatively tolerant of this type of chemotherapy in comparison with AST.

Neurotensin-mediated effects on astrocytic tumor cell proliferation

Neurotensin (NT) and neurotensin receptors (NTRs) are widely found in the brain, NT may be considered as a mitogen factor in some tissues. However, no NT-mediated effects on glioma cell proliferation have been reported so far. In our present study we investigated the influence of NT on the proliferation of astrocytic tumor cell lines. To this end we used a synthetic NT agonist (JMV-449), a protease inhibitor which blocks the natural degradation of NT (JMV-531), and NT. The in vitro biological models used in the present study included the low grade SW1088, and the high grade U87, U373 and A172 astrocytic tumor cell lines. The peptide-induced influence on astrocytic tumor cell proliferation was investigated by means of the colorimetric MTT assay. Our results show that the NT and the NT agonist significantly stimulated the proliferation in 2/4 and 3/4 of the astrocytic cell lines respectively. Similarly, compound JMV-531 also induced an increase in the proliferation of 2/4 of the astrocytic cell lines. This marked influence of the NT and NT agonists, or the enzyme-endogenous prevention of its degradation on the regulation of astrocytic tumor growth therefore suggests that NT antagonists might be used to treat certain patients with high grade astrocytic tumors that do not respond to chemotherapy and/or radiotherapy.

Characterization by means of Delaunay triangulation and Voronoi paving of the influence of anti-hormone and/or anti-growth factor antibodies on the in vitro cell growth of human colorectal neoplastic cell lines

A new tool is described which makes it possible to evaluate directly the influence of various growth factors on in vitro neoplastic cell growth on the one hand and to look at a concept of differentiation in terms of population dynamics, on the other. This tool relies upon the digital cell image analyses of Feulgen-stained nuclei and the mathematical method of Voronoi paving. This technique enabled us to characterize the influence on the proliferation and the differentiation of the HCT-15 and LoVo colorectal cell lines of anti-gastrin (G), anti-estradiol (E(2)), anti-epidermal growth factor (EGF), anti-luteinizing hormone-releasing hormone (LHRH), and anti-transforming growth factor alpha (TGF alpha) and beta (TGF beta) antibodies. Two variants were set up with respect to each of the two cell lines, i.e, one growing in culture medium supplemented with 5% fetal calf serum (FCS) and another supplemented with 1% FCS+10 nM G+10 nM E(2). The data show that it is possible to characterize the cell clone structure and to assess growth rate concomitantly by direct cell counts. It further appears that while the anti-hormone and/or anti-growth factor antibody-induced effects on growth were relatively similar, these effects were in sharp contrast at the level of cell clone architecture.

Lectin histochemistry, ploidy level and proliferation indices in meningioma subtypes

The glycohistochemical expression of binding sites for eight lectins is characterized in a series of 15 meningothelial, 10 fibroblastic and 15 transitional meningiomas. The correlation between lectin staining and either the proliferation index or ploidy level has also been investigated. The data show that the cytochemical binding of some lectins is of value in distinguishing between the different meningioma subgroups. For example, fibroblastic meningiomas express significantly higher amounts of wheat germ agglutinin (WGA) and Ulex europaeus agglutinin (UEA-I) than the meningothelial sub-type. Diploid tumours express a higher glycine maximus (SBA), Arachis hypogaea (PNA) and Phaseolus vulgaris leukoagglutinin (PHA-L) binding than aneuploid tumours. These differences are probably due to the modification of post-transcriptional glycosylation events linked to tumour ageing. The data also reveal that the increased binding of PHA-L is inversely correlated with the proliferation indices of the tumours.

Lectin histochemistry, ploidy level, and proliferative activity in rhabdomyosarcoma subtypes

The glycohistochemical expression of binding sites for eight lectins is characterized in a series of 8 embryonal, 4 alveolar and 4 pleomorphic rhabdomyosarcomas. The correlation between lectin staining and either the proliferation index or the ploidy level was also investigated. The data show that rhabdomyosarcomas exhibit heterogeneous lectin binding expressions. A comparable level of lectin labeling is observed in euploid and aneuploid tumours. In contrast to other neoplasms, lectin staining has proved to be of doubtful value in distinguishing between different RMS subtypes. The data also reveal that a significantly lower level of proliferative activity was observed in the pleomorphic group as compared to the alveolar one.

DNA ploidy level assessments in 83 human brain metastases. Relationship to the survival of 35 patients

The nuclear DNA content (DNA ploidy) level was determined in a series of 83 human brain metastases, for which 35 complete clinical follow-ups were available. The DNA ploidy level determination was carried out by means of DNA histogram types. The results show that certain brain metastases were diploid, while others exhibited aneuploidy levels ranging from low to very high. The present study also shows that a significant proportion, i.e. 18%, of the 83 brain metastases, exhibited very high levels of aneuploidy, i.e. hypertetraploidy, hyperpentaploidy and octoploidy. We have previously observed that this feature appeared only rarely, i.e. in less than 2% of primary nervous tumours. Furthermore, the present study shows that DNA ploidy level in brain metastases is related significantly (P < 0.001) to patient survival. Indeed, while 9/13 (69%) patients with diploid brain metastases survived longer than 9 months, none (0%) of the 22 patients with aneuploid brain metastases survived longer than the 9 months following the diagnosis of their brain metastases.

The use of the digital cell image analysis of Feulgen-stained nuclei to detect apoptosis

Cell death is an essential event in the functioning of multicellular organisms. It plays a role opposite to that of mitosis in the regulation of cell populations. In the present work, we describe an original methodology which permits the easy detection and count of apoptotic cells in a given tissue. This methodology is based on the digital cell image analysis of Feulgen-stained nuclei, which also permits the calculation of the proliferation index, i.e. the percentage of cells in the S phase of the cell cycle. This percentage of cells in the S phase is strongly related to the mitotic index. Our methodology, which involves the multivariate analysis of 14 morphonuclear parameters computed by means of the digitized cell image analysis of Feulgen-stained nuclei, was applied here to a well-known biological apoptosis model, namely glucocorticoid-treated rat thymocytes. The parameters that permitted the detection of apoptotic cells were the integrated optical density, a parameter that describes the nuclear DNA content, and the run length percentage and long run length parameters which are related to the pattern of chromatin condensation. This determination can be carried out on a relatively small number of cells.

Stereotactic biopsies from astrocytic tumors. Diagnostic information contributed by the quantitative chromatin pattern description

OBJECTIVE

To reduce the problem of heterogeneity in astrocytic tumors by means of computer-assisted microscope analysis of Feulgen-stained nuclei.

STUDY DESIGN

Thirty-eight glial tumors for which we obtained 227 stereotactic biopsies were subjected to digital cell image analysis of Feulgen-stained nuclei. This series of 38 glial tumors included 36 supratentorial astrocytic tumors (13 astrocytomas, 7 anaplastic astrocytomas and 16 glioblastoma multiformes) and 2 grade 3 astrocytic tumors of the cerebellum.

RESULTS

The results suggest a new methodology, enabling the biologic characteristics of the brain parenchymal area surrounding a given glial tumor to be characterized. This methodology relies on the performance of three successive steps. The first is quantitative characterization of nuclear morphology and its chromatin pattern by means of 15 morphonuclear variables. This characterization is carried out by means of the computer-assisted microscope analysis of Feulgen-stained nuclei. The second step consists of setting up morphonuclear data banks, with each process giving the precise portrait of a given cell nuclear population. This process is carried out by means of multivariate analysis, taking into account the 15 variables mentioned above. Multivariate analysis includes principal components analysis followed by the canonical transformation of the data. The third step consists of testing unknown cases against these morphonuclear data banks. This is carried out by means of linear discriminant analysis, which enables the various cell nuclear types in the stereotactic biopsy to be quantified.

CONCLUSION

The present methodology makes it possible to investigate whether infiltrating tumor cells are present in or absent from the parenchymal brain area surrounding a glial tumor. It can therefore contribute additional information to that contributed by computed tomography and/or magnetic resonance imaging with respect to the precise delineation of the volume of a brain tumor. This delineation must be as precise as possible to allow total surgical resection of the tumor and prevention of its recurrence.

Aneuploidy occurrence in human tumours: a logical-automaton approach

The search for new, reliable factors of prognosis in cancerology is sadly deficient at the present moment. Of these factors, the measurement of ploidy gives rise to considerable hope. Nevertheless, despite the impressive number of papers currently published, no general law seems to be emerging that associates the ploidy rate of a tumour with its clinical evolution in a patient. The purpose of the present work is firstly to use a logical automation to describe the cell cycle in terms of binary variables (the validation of the methodology), and secondly to demonstrate that a certain 'cancer logic' can be distilled, at least with respect to the genesis of DNA histograms among tumours.

The combination of a decision tree technique with the computer-assisted microscope analysis of Feulgen-stained nuclei to assess aggressiveness in lipomatous and smooth muscle tumors

The present study describes a computer-assisted methodology whose purpose is to reduce the degree of subjectivity in the diagnosis of soft tissue tumors. This methodology associates three complementary techniques, namely digital cell image analysis, the discretisation of numerical data and a Decision Tree technique (DT). The first technique relies on the use of the digital cell image analysis of Feulgen-stained nuclei, a technique which makes possible a quantitative and thus objective description of nuclei with the help of 24 numerical parameters (15 morphonuclear and 9 DNA content- (ploidy level and proliferation activity) related). The second technique transforms each numerical parameter into an ordinal one with a small number of values (2 to 4) so that only the relevant physical significance of the parameters is retained. The Decision Tree technique generates classification rules on the basis of the discretised parameters quoted above. This methodology was applied to 53 human soft tissue tumors which included 26 lipomatous tumors (13 malignant liposarcomas and 13 benign lipomas) and 27 smooth muscle tumors (11 malignant leiomyosarcomas and 16 benign leiomyomas). The results show that a distinction between benign (lipoma) and malignant (liposarcoma) lipomatous tumors can easily be made by means of simple logical rules depending on only four discretised cytological parameters (two ploidy- and two morphonuclear-related). In contrast, no stable or predictive characterisation can be obtained with respect to the difference between leiomyosarcomas and the leiomyomas. Hence, while lipomas and liposarcomas appeared to be two completely distinct biological entities, leiomyomas and leiomyosarcomas seem to involve a continuous biological process.

Relationship between DNA ploidy level and tumor sociology behavior in 12 nervous cell lines

Cell population sociology was studied in two medulloblastomas and 10 astrocytic human tumor cell lines by means of the characterization of the structure of neoplastic cell colonies growing on histological slides. This was carried out via digital cell image analysis of Feulgen-stained nuclei, to which the Delaunay triangulation and Voronoi paving mathematical techniques were applied. Such assessments were compared to the DNA polidy level (assessed by means of DNA histogram typing). The results show that the cell colony architecture characteristics differed markedly according to whether the cell lines were euploid (diploid or tetraploid) or aneuploid (hyperdiploid, triploid, hypertriploid, or polymorphic). In fact, the cell colonies from the euploid cell nuclei populations were larger and more dense than those from the aneuploid ones. Furthermore, for an identical period of culture, the cell lines from high-grade malignant astrocytic tumors (glioblastomas) exhibited cell colonies that were larger and more dense than those in cell lines from low-grade astrocytic tumors (astrocytomas). In each of these two groups, the diploid cell nuclei populations exhibited cell colonies larger and more dense than the nondiploid colonies. The present methodology is now being applied in vivo to histological sections of surgically removed human brain tumors in order to distinguish between high-risk clinical subgroups and medium-risk subgroups in clearly circumscribed histopathological groups.

Identification of high versus lower risk clinical subgroups in a group of adult patients with supratentorial anaplastic astrocytomas

The present work investigates whether computer-assisted techniques can contribute any significant information to the characterization of astrocytic tumor aggressiveness. Two complementary computer-assisted methods were used. The first method made use of the digital image analysis of Feulgen-stained nuclei, making it possible to compute 15 morphonuclear and 8 nuclear DNA content-related (ploidy level) parameters. The second method enabled the most discriminatory parameters to be determined. This second method is the Decision Tree technique, which forms part of the Supervised Learning Algorithms. These two techniques were applied to a series of 250 supratentorial astrocytic tumors of the adult. This series included 39 low-grade (astrocytomas, AST) and 211 high-grade (47 anaplastic astrocytomas, ANA, and 164 glioblastomas, GBM) astrocytic tumors. The results show that some AST, ANA and GBM did not fit within simple logical rules. These "complex" cases were labeled NC-AST, NC-ANA and NC-GBM because they were "non-classical" (NC) with respect to their cytological features. An analysis of survival data revealed that the patients with NC-GBM had the same survival period as patients with GBM. In sharp contrast, patients with ANA survived significantly longer than patients with NC-ANA. In fact, the patients with ANA had the same survival period as patients who died from AST, while the patients with NC-ANA had a survival period similar to those with GBM. All these data show that the computer-assisted techniques used in this study can actually provide the pathologist with significant information on the characterization of astrocytic tumor aggressiveness.