Mechanisms of tumor angiogenesis and therapeutic implications: angiogenesis inhibitors

Angiogenesis is the development of new blood vessels from the existing vascular bed. In normal conditions this tightly regulated process occurs only during embryonic development, the female reproductive cycle and wound repair. In contrast, in pathological conditions such as malignant growth, atherosclerosis and diabetic retinopathy, angiogenesis becomes persistent due to an imbalance in the interplay between the positive and negative regulatory signals controlling the process. Thus, the control of tumor neovascularization may lead to new therapeutic approaches. Indeed, several anti-angiogenic drugs are currently undergoing preclinical characterization and/or clinical investigation. Recent achievement has clarified the mechanisms of action leading to pathological angiogenesis and has highlighted the role of hypoxia, growth factors, growth factor-receptors, enzymes and cell adhesion molecules involved in the process. This knowledge has permitted the design of receptor antagonists, adhesion molecule blockers and new targeted vascular approaches including gene therapy.

Improving the prognostic value of histopathological grading and clinical staging in renal cell carcinomas by means of computer-assisted microscopy

The present work aims to refine prognosis in cases of renal cell carcinoma (RCC) by integrating a variety of parameters with the prognostic information provided by histopathological grading and clinical staging, carried out on a series of 97 RCCs. To this end, Feulgen-stained RCC cell nuclei were characterized by means of 38 variables describing nuclear DNA ploidy levels and morphology. All of these data were subjected to a principal components analysis. On the basis of this multivariate analysis, Fuhrman grade II was subdivided into grades II- and II+, and Fuhrman grade III into grade III- and III+. The same kind of subcategorization was performed in the case of the T2 and T3 clinical stages. The results show that the classification into grade II- and III- RCCs correspond to a more favourable prognosis than grade II+ and III+, to which shorter survival periods were attributable. Similar results were obtained for the subcategorization of the T2 and T3 clinical stages. Very simple biological characterizations of these grade- or stage-related RCC groups were obtained by means of a decision tree approach applied to the cytometry-generated variables. The resulting classification rules were validated on a new series of 18 patients and enabled very accurate predictions of survival.

Corporeal veno-occlusive dysfunction: a distal arterial pathology?

PURPOSE

Alteration of intracavernous smooth muscle cells has been demonstrated in patients with pure venous leakage. This modification seems correlated with reduction of intracavernous oxygen tension. However, Doppler imaging of the cavernous arteries in these patients is normal. To understand the ischemic factor we studied the endothelium of the terminal arteries with computerized image analysis and immunohistochemical staining with 2 types of lectin in patients with venous leakage and those with normal erections. Lectins are glycoproteins that can be used as histological markers to monitor functional and pathological changes.

MATERIALS AND METHODS

Four patients 44 to 59 years old with normal erections who were operated on for penile cancer and 11 patients 27 to 62 years old with pure venous leakage (flow to maintain erection greater than 15 ml. per minute and cavernous flow velocity greater than 35 cm. per second) were included in the study. Immunohistochemical staining with 2 lectins, wheat germ agglutinin and Ulex europeaus agglutinin I, was performed and analyzed with computerized image analysis. The labeling index which relates to the percentage of staining indicates the distribution of the endothelial cells, and mean optical density which relates to the staining intensity indicates the function of these cells.

RESULTS

Mean labeling index values for the 2 lectins were similar in both groups (p >0.05). Mean optical density values for the 2 lectins were significantly greater for the patients with normal erections (p <0.01). Therefore, the distribution of the endothelial cells was the same while their function was different in patients with corporeal veno-occlusive dysfunction.

CONCLUSIONS

Staining with wheat germ agglutinin and Ulex europeaus agglutinin I lectin types allowed us to detect alteration in the glyco-histochemistry of the endothelial cells of the small arteries, and venous leakage could be the first step in vasculogenic impotence.

Use of image cytometry to classify biliary and ampullary adenocarcinomas

OBJECTIVE

To create an objective classification system to perform TNM classification of ampullary adenocarcinoma and cholangiocarcinoma using image cytometric data derived from Feulgen-stained tumor nuclei.

STUDY DESIGN

Surgically resected cases of ampullary adenocarcinoma and cholangiocarcinoma with established TNM classifications were selected on the basis of available formalin-fixed, paraffin-embedded tissue. Fifteen numerical variables related to morphometric, densitometric and textural features of each tumor nucleus were recorded. We employed a methodology based on multivariate statistical tools to characterize the association of morphonuclear variables with TNM classification. The first step consisted of identifying and selecting representative nuclei of each T class. From this "purified" data set an objective classification system was created. The classification system was assessed using internal and external validation.

RESULTS

Employing ANOVA, all 15 variables were significantly associated with T classification, 11 of 15 with N and 4 with M. Multivariate analysis was employed to distinguish between T1, T2 and T3 lesions. Our methodology correctly classified 76% of T1 nuclei, 47% of T2 nuclei and 84% of T3 nuclei. Heterogeneity within an individual tumor was defined in 61% of cases included in the training set. Complete concordance between pathologic classification and the classification system was observed in 71% of an independent validation.

Gastrin inhibits motility, decreases cell death levels and increases proliferation in human glioblastoma cell lines

Whether they are of low or high histopathological grade, human astrocytic tumors are characterized by a marked propensity to diffuse into large areas of normal brain parenchyma. This invasion relates mainly to cell motility, which enables individual cell migration to take place. The present study characterizes in vitro the gastrin-mediated effects on both the growth (cell proliferation vs. cell death) and motility dynamics of the human U87 and U373 glioblastoma cell lines. A computer-assisted phase-contrast microscope was used to track the number of mitoses versus cell deaths every 4 min over a 72-h period and so to quantitatively describe the trajectories of living U373 and U87 cells growing on plastic supports in culture media both with and without the addition of 0.1, 5, or 100 nM gastrin. While 5 or 100 nM gastrin only weakly (p < .05 to p < .01) increased cell proliferation in the U87 cell line and not in U373 one, it very significantly (p < .001) inhibited the amount of cell death at 5 and 100 nM in both the U87 and U373 lines. In addition, 5 nM gastrin markedly inhibited cell mobility in U87 (p < .00001) and U373 (p < .0001) glioblastoma models. All these data strongly suggest that gastrin plays a major role in the biological behavior of the in vitro U87 and U373 human glioblastoma cell lines in matters concerning their levels of cell motility and growth dynamics.

Setting up of an original computer-assisted methodology to characterize in vitro drug-induced anti-angiogenic effects

The development of angiogenesis within a tumor brings on a sequence of extremely complex molecular events. We have developed a methodology which enables a wide set of biological parameters to be quantitatively determined in the field of anti-angiogenesis pharmacology. This methodology which includes a video cell tracking device, is unique because it offers the possibility of evaluating the specific influence of a given compound with potential anti-angiogenic properties on cell cycle kinetics, cell death, global cell line growth, and cell motility. We chose TNP-470, a synthetic analogue of fumagilin, to test our methodology on HUVEC cell lines taken from various human umbilical cord veins. The experiments carried out with TNP-470 did not confirm all the data reported in the literature. Our results show that i) TNP-470 could be considered as a cytotoxic agent; ii) this compound had an apparently marginal cytostatic effect; and iii) it did not increase the apoptosis level. Our methodology also revealed that the HUVEC cell lines are very heterogeneous in terms of different biological parameters. This highlights the problem of the reproductibility of the result.

[Evidence of new diagnostic and prognostic human astrocytoma tumor markers. Potential therapeutic applications. II]

Human astrocytic tumors grow into the normal brain parenchyma either as localized tumors, or as highly diffuse neoplasms. The diffuse phenotype relates to a specific sub-type of neoplastic astrocytes with a high motility and invasion capacity. Motility features refer to locomotion while invasion features refer to protease secretion. Our data reveal that several peptides belonging to the gastrin/cholecystokinin peptide class are able to significantly (and in certain cases very significantly) modify the level of tumor growth (at the level of cell proliferation and/or cell death), of motility and of invasion in various experimental models of human astrocytic tumors. We are synthesizing various gastrin/cholecystokinin-related peptides in order to develop clinical applications with which we want to inhibit astrocytic tumor growth, individual neoplastic astrocytic motility and the invasion of the normal brain parenchyma.

Determination of growth fraction and cell density to evaluate the potential growth of human oligodendroglial and astrocytic tumours

The object of this work was

PURPOSE

to develop a methodology that enables net tumour growth, a balance between actual tumour growth and tumour cell loss, to be approximately evaluated.

METHODS

The methodology proposed relies on detecting the growth fraction immunohistochemically by means of MIB-1 antibody labelling combined with cell density determination, carried out on 5-microm-thick Feulgen-stained histological sections with computer-assisted microscopy. The series investigated included 25 oligodendrogliomas (OLG-II), 9 anaplastic oligodendrogliomas (OLG-III). 13 astrocytomas (AST), 14 anaplastic astrocytomas (ANA) and 8 mixed oligoastrocytomas (OLG-AST).

RESULTS

The results show that the biological characteristics of some cases were in total accordance with their histopathological diagnoses. This was the case for the "weakly proliferating weakly dense" OLG-II and AST-II tumours, and for the "highly proliferating highly dense" OLG-III and AST-III ones. In contrast, the biological characteristics of some cases seemed to contradict the histopathological case labels. This was the case for the "highly proliferating highly dense" OLG-II and AST-II tumours, the biological aggressiveness of which would be undervalued on the basis of the morphology-based grading system alone, and also for the "weakly proliferating weakly dense" OLG-III and AST-III tumours, the aggressiveness of which would be overvalued.

CONCLUSIONS

Combining the determinations of the MIB-1 and the cell density variables appears to be satisfactory in terms of the cell kinetic characterization of glial tumours as a complement to the prognostic information given by a morphology-based grading system alone.

Growth inhibition of human in vitro and mouse in vitro and in vivo mammary tumor models by retinoids in comparison with tamoxifen and the RU-486 anti-progestagen

Retinoids constitute a very promising class of agents for the chemoprevention or treatment of breast cancer. These retinoids exert their biological activity through two distinct classes of retinoic acid (RA) receptors (R), the RAR isotypes (alpha, beta, and gamma) and the three RXR isotypes (alpha, beta, and gamma) and their numerous isoforms which bind as RXR/RAR heterodimers to the polymorphic cis-acting response elements of RA target genes. With respect to these numerous receptor sub-types, the retinoid-induced effects at the biological level include marked modifications with respect to both cell proliferation and cell death (apoptosis), and also in the induction of differentiation processes. The present study aims to characterize the effect which four retinoids (TTNPB, 9-cis-RA, LGD 1069, 4-HPR) with distinct RAR/RXR binding properties induced on various in vitro and in vivo mouse and human breast cancer models. The experiments with the retinoids were carried out in comparison with the anti-estrogen tamoxifen and the anti-progestagen RU-486 compounds. The results show that the 6 compounds under study were markedly more efficient in terms of growth inhibition in the human T-47D cell line when maintained under anchorage-independent culture conditions than when maintained under anchorage-dependent ones. While RU-486 exhibited a weak statistically significant (p < 0.05) influence on the growth of the T-47D stem cells, tamoxifen had a marked inhibitory influence on the growth of these cells. Of the four retinoids, 4-HPR was the least effective since the lowest doses tested (1 and 0.1 nM) exhibited no statistically (p > 0.05) significant influence on the growth of the stem cells. The most efficient retinoid was TTNPB. It was only at the highest dose (10 microM) that tamoxifen and RU-486 showed a weak inhibitory influence on the growth of the T-47D non-stem cells while all 4 retinoids exerted a significant inhibitory influence on the growth of these non-stem cells, with 4-HPR being the most efficient (P < 0.001) at the highest dose, but ineffective (P > 0.05) at the lowest. Tamoxifen and TTNPB were tested in vivo on hormone-sensitive (HS) and hormone-insensitive (HI) strains of the MXT murine mammary carcinoma. While TTNPB appeared to be equally efficient in terms of growth inhibition in both MXT-HS and MXT-HI models, tamoxifen had only a marginal inhibitory influence on the growth of the MXT-HI strain but did inhibit growth in the case of the MXT-HS one. TTNPB was markedly more efficient than tamoxifen in terms of both inhibiting the cell proliferation level (measured by means of computer-assisted microscopy applied to Feulgen-stained nuclei, a method which enables the percentage of cells in the S phase of the cell cycle to be determined) and triggering cell death (measured by means of the determination of the transglutaminase activity) in both the MXT-HI and MXT-HS models. The very significant TTNPB-induced inhibition of the macroscopic MXT-HS growth rate relates to the triggering of cell death (apoptosis) rather than to an inhibition of cell proliferation. All these results clearly indicate that retinoids are very efficient agents against breast cancer, at least as efficient as tamoxifen.

Characterization of astroglial versus oligodendroglial phenotypes in glioblastomas by means of quantitative morphonuclear variables generated by computer-assisted microscopy

The current WHO classification places glioblastomas in the astrocytoma category. However, whether or not glioblastomas also show oligodendroglial differentiation remains a matter of controversy. This study investigates, at the morphonuclear level, the hypothesis that some glioblastomas (GBMs) may also represent the ultimate level of malignancy in the oligodendroglial lineage. Using a series of 164 GBMs, we sought to ascertain whether any of these GBMs exhibited phenotypical characteristics that were more closely related to oligodendroglial lineages than astrocytic lineages. Phenotypical features were quantitatively determined by means of the computer-assisted microscope analysis of Feulgen-stained nuclei, a process that made it possible to quantitatively describe the patterns of the cell nuclei (and, more specifically, of their chromatin) through 16 variables, and the distribution of the nuclear DNA content (DNA ploidy) through 8 variables. The phenotypical characteristics typical of astrocytic and oligodendroglial tumors were analyzed by means of Discriminant Analysis, a statistical multivariate analysis, performed on a series of 65 astrocytic and oligodendroglial tumors. This series consisted of 14 WHO grade II and 19 grade III astrocytomas and 24 WHO grade II and 8 grade III oligodendrogliomas. This multivariate analysis enabled an accurate model to be produced that distinguished between astrocytomas and oligodendrogliomas on the basis of 5 cytometry-generated variables. This model was used to characterize the phenotype of each of the 164 glioblastomas. The results show that of these 164 glioblastomas, 6 (about 3.5%) displayed phenotypes that were very similar to oligodendrogliomas, and 141 displayed phenotypes that were very similar to astrocytomas. The phenotypes of the 17 remaining GBMs were too ambiguous to be categorized as having a pure astrocytic or oligodendroglial lineage.

Discrimination between chronic pancreatitis and pancreatic adenocarcinoma using artificial intelligence-related algorithms based on image cytometry-generated variables

The incidence of pancreatic adenocarcinomas (PA) is increased in the setting of chronic pancreatitis. Distinguishing chronic pancreatitis from pancreatic adenocarcinomas is often difficult, and is based on routine brush cytological specimens provided during endoscopic retrograde cholangiopancreatography (ERCP). Reactive epithelial changes in chronic pancreatitis may appear similar to those of a well-differentiated cancer. Brush cytology specimens were obtained during ERCP from 49 patients with diseases for which the differential diagnosis included chronic pancreatitis and/or pancreatic adenocarcinoma Image cytometry was performed involving the assessment of between 200-400 Feulgen-stained nuclei per case; for each case, 40 quantitative cytometric variables were generated. Data analysis was performed using artificial intelligence methods of data classification that produced decision trees and production rule systems. Different classification models were produced for a subset of 34 patients. The best models were identified by the use of a sampling technique (leave-one-out), and were tested on the remaining 15 patients. These models were based on 5 of the 40 variables associated with a significant discriminatory function. Pancreatic adenocarcinoma was diagnosed in the training data set of 34 patients during a leave-one-out process with an estimated sensitivity of 91% and specificity of 87%. Both sensitivity and specificity were 80% in the independent test set of 15 patients. We conclude that inflammatory and malignant pancreatic epithelia exhibit distinct morphological features that can be distinguished by decision tree-based classifiers employing image-cytometric numerical data.

The in vitro influence of eight hormones and growth factors on the proliferation of eight sarcoma cell lines

Little is known about the regulation of sarcoma proliferation by hormones and/or growth factors. We therefore characterised the in vitro proliferative influence on eight sarcoma cell lines of the platelet-derived growth factor, the insulin-like growth factor 1, triiodothyronine, the epidermal growth factor, the luteinising-hormone-releasing hormone, progesterone, gastrin and 17 beta-oestradiol. The influence of the different factors on the proliferation of sarcoma cell lines was measured by the colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test. Two culture media were studied: (1) a nutritionally poor medium containing 2% of fetal calf serum and (2) a nutritionally rich one containing 5% or 10% FCS both with and without the addition of non-essential amino acids. The results were analysed either by conventional statistical analyses or by a classification method based on a decision-tree approach developed in Machine Learning. This latter method was also compared to other classifiers (such as logistic regression and k nearest neighbours) with respect to its accuracy of classification. Monovariate statistical analysis showed that each of the eight cell lines exhibited sensitivity to at least one factor, and each factor significantly modified the proliferation of five or six of the eight cell lines under study. Of these eight lines one of fibrosarcoma origin was the most "factor-sensitive". Decision-tree-related data analysis enabled the specific pattern of factor sensitivity to be characterised for the three histological types of cell line under study. The effects of hormone and growth factors are significantly influenced by the type of culture medium used. The method used appeared to be an accurate classifier for the kind of data analysed. Sarcoma proliferation can be modulated, at least in vitro, by various hormones and growth factors, and the proliferation of each histopathological type exhibited a distinct sensitivity to different hormone and/or growth-factors.

Prognostic value of stem cell line identification for renal cell carcinomas

OBJECTIVE

To investigate the prognostic value of nuclear DNA content (DNA ploidy level) in a series of 95 renal cell carcinomas (RCCs).

STUDY DESIGN

Eight variables were used to characterize DNA ploidy levels. They included DNA index and seven others characterizing the presence of specific stem cell lines in each of the 95 RCCs under study. All these variables were determined by means of computer-assisted microscopy applied to Feulgen-stained nuclei. The actual information contributed by each of the eight variables was determined by means of univariate statistical analyses.

RESULTS

The results showed that in the DNA ploidy-related eight variables, the presence of at least 4% aneuploid nuclei with > 5C DNA content was associated with the most significant prognostic value in RCCs with intermediate (T2, T3) invasion levels.

CONCLUSION

The present study clearly showed that stem cell line characterization, and particularly the presence of highly aneuploid cells (with > 5C DNA content), is associated in RCCs with significant prognostic value. This kind of marker may help the identification of patients who will develop metastases after surgery and for whom adjuvant therapy might thus be indicated.

Image cytometry as a discriminatory tool for cytologic specimens obtained by endoscopic retrograde cholangiopancreatography

BACKGROUND

Routine brush cytology is relatively insensitive for the diagnosis of biliary and pancreatic malignancy. Sensitivity can be improved by measuring DNA and proliferation. The goal of this study was to assess the discriminatory capacity of image cytometry using pancreaticobiliary brush cytology specimens obtained during endoscopic retrograde cholangiopancreatography (ERCP). Analysis included morphometry, DNA quantification, and characterization of nuclear chromatin distribution and condensation.

METHODS

Brush cytology specimens were obtained during ERCP from 22 chronic pancreatitis specimens, 11 pancreatic adenocarcinoma specimens, 13 primary sclerosing cholangitis specimens, and 11 cholangiocarcinoma specimens and contrasted with 25 normal epithelia specimens. A SAMBA 2005 image processor was used to analyze Feulgen stained chromatin density and distribution. Discriminant analysis of 37 morphonuclear variables was performed to characterize differences between: 1) chronic pancreatitis and pancreatic adenocarcinoma, and 2) primary sclerosing cholangitis and cholangiocarcinoma.

RESULTS

Chronic pancreatitis was distinguished from pancreatic adenocarcinoma (P < or = 0.001); sensitivity and specificity were both estimated to be 82%. Primary sclerosing cholangitis was distinguished from cholangiocarcinoma (P < or = 0.01); sensitivity and specificity were estimated to be 82% and 85%, respectively.

CONCLUSIONS

Multiparameter image cytometry has potential as an adjuvant diagnostic technique in patients with pancreaticobiliary malignancy.

Direct relationship between hormone sensitivity level and growth pattern. Evidence in 18 gastrointestinal neoplastic cell lines

OBJECTIVE

We investigated whether a relationship exists in terms of growth pattern and hormone sensitivity in 18 gastrointestinal neoplastic cell lines. Hormones studied included gastrin, epidermal growth factor, estradiol and luteinizing hormone-releasing hormone.

STUDY DESIGN

The growth patterns were assessed by means of computer-assisted microscope analysis of Feulgen-stained nuclei combined with the mathematical Delaunay triangulation and Voronoi paving techniques. This methodology enabled four variables characterizing the cell colony patterns to be computed. The information contributed by these variables was analyzed by means of discriminant analysis and the decision tree technique.

RESULTS

Each phenotype (sensitivity level) exhibited distinct growth pattern (or cell colony) characteristics in the case of each hormone and/or growth factor under study. Furthermore, the sensitivity of the gastrointestinal cell lines to a given hormone (or growth factor) appeared to be peculiar to the hormone (or growth factor).

CONCLUSION

A direct relationship seems to exist between growth pattern and hormone sensitivity levels in gastrointestinal cancers, particularly colorectal.

Quantitative glycohistochemistry defines new prognostic markers for cancers of the oral cavity

BACKGROUND

Histopathologic grading and clinical staging cannot provide a precise prognosis of oral cavity cancer patients. The use of glycohistochemical markers may improve the level of prognostic accuracy of such conventional classification systems.

METHODS

Computer-assisted microscopy was employed in a series of 40 oral cavity cancers to determine quantitatively the percentage of positive cells, the staining intensity, and the level of staining heterogeneity for 3 glycohistochemical markers, including peanut agglutinin (PNA), Thomsen-Friedenreich antigen (T antigen) as part of a neoglycoprotein, and sarcolectin. Data were evaluated by discriminant analysis.

RESULTS

Although the level of differentiation (P < 0.01 to P < 0.001) and the T variable of the TNM staging system (P < 0.05 to P < 0.01) related mainly to the level of expression of the acceptor sites for PNA and the T antigen, the patient survival period (P < 0.05) was largely a fraction of the level of expression of the acceptor sites for the carrier-immobilized T antigen and for sarcolectin.

CONCLUSIONS

In oral cavity cancer, determining the level of acceptor sites for PNA, T antigen, and sarcolectin provides useful information on histopathologic differentiation, clinical staging, and survival. Because these processes of determination were carried out quantitatively, a discriminant model was set up, which enabled the level of oral cavity cancer aggressiveness to be characterized precisely. The current methodology described in this article should therefore afford pathologists original and quantitative (and thus objective) prognostic markers for oral cavity cancers.

The chromatin pattern of cell nuclei is of prognostic value for renal cell carcinomas

Using a series of 105 renal cell carcinomas (RCCs) we investigated whether features quantitatively describing the appearance of Feulgen-stained nuclei and, more particularly, of their chromatin (on the basis of computer-assisted microscopy) can contribute any significant prognostic information. Thirty morphonuclear and 8 nuclear DNA content-related variables were thus generated. The actual prognostic values of this set of cytometric variables was compared (by means of discriminant statistical analysis) to conventional diagnostic and/or prognostic markers including histopathological grades, tumour invasion levels and the presence or absence of metastases. We obtained complete clinical follow-ups for 49 of the 105 RCC patients under study, making it possible to define a subset of patients with a bad prognosis (i.e., who died in the 12 months following nephrectomy) and a subset of patients with a good prognosis (i.e., who survived at least 24 months following nephrectomy). An original method of data analysis related to artificial intelligence (decision tree induction) enabled a strong prognostic model to be set up. In the case of 10 new patients, this model identified all the dead patients as having a bad survival status, with a total of 8 correct predictions. Another prognostic model similarly generated enabled the correct predictions to be confirmed.

Algorithm analysis of lectin glycohistochemistry and Feulgen cytometry for a new classification of nasal polyposis

The aim of this study is to present a new classification of nasal polyps. This classification is based both on morphologic criteria relating to morphonuclear features from isolated Feulgen-stained nuclei and on glycohistochemical characteristics from histologic slides submitted to three lectins (peanut, wheat germ, and gorse seed agglutinins) and one neoglycoconjugate glycohistochemical stain. While the morphonuclear features (including 30 variables) relate essentially to chromatin pattern, the glycohistochemical stains (including 16 variables) are linked to the presence of specific carbohydrate moieties in cell membranes and cytoplasm. Forty-nine nasal polyps, including single polyps, diffuse polyposis, cystic fibrosis-related polyposis, and aspirin idiosyncracy-related polyposis associated with asthma, were thus characterized. All the variables were obtained quantitatively by means of computer-assisted microscopy. Two complementary methods of data classification were used to determine the actual diagnostic value contributed by each quantitative variable, namely, discriminant analysis, which forms part of multifactorial statistical analysis, and the decision tree technique, which is an artificial intelligence-related algorithm. The data so obtained show that our morphologic classification of nasal polyps fits in with the classification of nasal polyps defined on the basis of clinical criteria.

Biochemical alterations of the tunica albuginea in impotence

PURPOSE

The objectives of this study were to quantify the immunohistochemical stainings of collagen types I, III and IV, and investigate the value of glycohistochemical staining with 3 lectin types specific to a particular glycan structure, Arachis hypogaea, Triticum vulgare and concanavalin A, as a method of defining possible changes in the collagen structure of the tunica albuginea in potent and impotent patients.

MATERIALS AND METHODS

The study involved 4 normal men, 4 with pure venous leakage and 4 with pure arterial disease. Collagen types I, III and IV, and lectins Arachis hypogaea, Triticum vulgare and concanavalin A were studied using a cell image processor. The labeling index relates to the percentage of staining and mean optical density relates to the staining intensity.

RESULTS

Mean labeling index values for the 3 types of collagen and lectins were similar (p > 0.05). Mean optical density value relating to collagen type I was significantly higher in the arteriogenic group than in the other groups (p < 0.05), while mean optical density value of collagen type IV was significantly higher in the venogenic group than in the 2 other groups (p < 0.05). Mean optical density values relating to the 3 lectin types were similar in the 3 clinical groups (p > 0.05).

CONCLUSIONS

An alteration in the distribution and structure of the various collagen types and lectins in the tunica albuginea of impotent patients has been shown that may interfere with normal function and lead to impotence.

Determination of proliferative activity in nasal polyps

AIMS

To determine the level of proliferative activity in 39 nasal polyps with clear cut distinct clinical behaviour patterns.

METHODS

The 39 nasal polyps included 11 polyps labelled as "single" and taken from the lateral nasal wall and the middle turbinate; 12 polyps labelled as "massive" and relating to diffuse polyposis involving the entire nasal cavity; six polyps labelled as "ASA" and relating to nasal polyps from patients with acetylsalicylic acid intolerance and asthma; and 10 polyps from cystic fibrosis related polyposis. Cell proliferation was determined by two independent methods: first, the computer assisted microscope analysis of isolated Feulgen stained nuclei for the measurement of the percentage of cells in the S phase of the cell cycle; and second, the immunohistochemical evaluation of a proliferation associated protein by means of the MIB 1 monoclonal antibody.

RESULTS

The cystic fibrosis related polyposis exhibited the highest proliferative activity of all the clinically identified nasal polyp groups. Acute inflammatory nasal polyps exhibited a higher cell proliferation than chronic ones. The results also show that while the immunohistochemical determination of cell proliferation by means of the MIB 1 monoclonal antibody is a valuable tool in determining cell proliferation in nasal polyps, the cytometrical image analysis of Feulgen stained nuclei is not useful for this purpose.

CONCLUSION

Cell proliferation activity identifies cystic fibrosis as being distinct from the other nasal polyp groups.

Classification strategies for the grading of renal cell carcinomas, based on nuclear morphometry and densitometry

The various grading systems proposed for renal cell carcinomas all suffer from problems related to inter-observer variability. Some of these grading systems are based, either partially or wholly, on morphonuclear criteria, such as nuclear size and shape, anisonucleosis, and chromatin pattern. These criteria can be quantitatively (and thus objectively) evaluated by means of the computer-assisted microscopic analysis of Feulgen-stained nuclei. In the present work, 39 quantitative variables, including two morphometric, 28 chromatin pattern-related, and nine DNA ploidy level-related, were computed for 65 renal cell carcinomas. The actual diagnostic information contributed by each variable was determined by means of multifactorial statistical analysis (discriminant analysis) and two artificial intelligence-related methods of data classification (the decision tree and production rule methods). The results show that quantitative information, as provided by the computer-assisted microscopy of Feulgen-stained nuclei and analysed by means of artificial intelligence-related methods of data classification, contributes significant diagnostic information for the grading of renal cell carcinoma, thus reducing the problem of inter-observer reproducibility.

Correlation between gender and cytomorphonuclear characteristics in human melanomas and in vitro evidence of sex steroid-induced modifications in the morphonuclear characteristics of three human melanoma cell lines

The influence of gonadal steroids on human melanoma still remains a controversial issue. The aim of our study was to investigate whether sex steroids may influence the biological characteristics of human melanoma. Such biological characteristics were monitored at the morphological level by means of computer-assisted microscope analysis of Feulgen-stained nuclei, which provides 28 quantitative variables describing the nucleus morphometry (size, anisonucleosis level) and chromatin pattern. This methodology was used to characterize the morphonuclear features in a series of 69 human melanomas (from formalin-fixed paraffin embedded tissues) including 28 male, 17 premenopausal and 24 postmenopausal female patients, and to investigate the effect of two sex steroids (5-alpha-dihydrotestosterone [DHT] and 17-beta-oestradiol [E2]) on three human melanoma in vitro models--the HT-144, SK-MEL-28 and C32 cell lines. The results show that the morphonuclear characteristics of melanoma originating from male and female patients are very distinct (P < 0.01). This difference is still more marked (P < 0.0005) when only premenopausal female patients are compared with male patients. The in vitro data show that both DHT and E2 are able to modify markedly (P < 0.001 to P < 0.0001) the nucleus morphometry and chromatin pattern of the three cell lines. Although the mechanism and the physiological outcome are still unknown, the present work shows that there is in vivo and in vitro evidence that the biological behaviour of human melanoma is influenced by sex steroids.

In vitro characterization of lectin-induced alterations on the proliferative activity of three human melanoma cell lines

Lectin binding is known to be able to elicit signalling events relevant for various aspects of cell physiology. The influence of lectin binding on melanoma cells remains relatively unexplored. The aim of our study was to investigate the in vitro effects of five plant lectins, namely peanut (PNA), wheat germ (WGA), concanavalin A (Con-A), Griffonia simplicifolia (GSA-IA4) and Phaseolus vulgaris (PHA-L) agglutinins, on the cell proliferation of melanoma cell lines (SK-MEL-28, HT-144 and C32) cultured in media supplemented with either 10% or 1% fetal calf serum (FCS). Cell proliferation was assessed by means of the tetrazolium derivative reduction (MTT) assay. Four lectin concentrations were tested, namely 0.05, 0.5, 5 and 50 micrograms/ml, in four experimental settings, namely 1, 3, 5 and 7 days after the addition of each lectin to the culture media. Determination of the cell gain compartment (percentage of cells in the S and G2 phases of the cell cycle) was done by means of digital cell image analysis assessed on Feulgen-stained nuclei. Our results demonstrated that of the five lectins under study, four had a globally significant dose-dependent toxic effect on melanoma cell proliferation. The fifth lectin, PNA, had a significant stimulatory effect on the C32 cell line. Low doses of lectins may produce a transient increase in cell proliferation. Increasing the FCS from 1% to 10% in the culture media significantly antagonized lectin-induced toxicity in the three cell lines. The cell kinetics measurements showed that the inhibition of cell growth was merely due to cell death. The present data strongly suggest that some lectins might influence the proliferation of melanoma cells. In addition, because lectins are present in our diet and are able to pass into the systemic circulation, we speculate that lectins may exert an influence on melanoma growth under clinical conditions.

Ploidy level determination and quantitative chromatin pattern description in pregnancy-associated breast cancers

The present study deals with the characterization of hormone-sensitivity in pregnancy-associated breast cancers (PBCs). This characterization was carried out in 22 PBCs as opposed to 88 non-pregnancy-associated breast cancers (NPBCs). For this study, we used the digital cell image analysis of Feulgen-stained nuclei to assess the type of hormone-sensitivity. In a previous study it was demonstrated that the chromatin pattern in breast cancers is related to the amounts of estrogen receptors they contain. Our results demonstrated that the quantitative description of the chromatin pattern by means of 15 parameters (relating to morphometric, densitometric, and textural features) made it possible to identify typical cell nuclei populations in the PBC and NPBC groups. The use of specific statistical analyses (principal-components and discriminant) made it possible to quantify the proportion of each cell nucleus type in the PBCs. Furthermore, of the 22 PBCs under study, 13 contained a large majority of cell nuclei whose chromatin pattern was characteristic of hormone-sensitive cells, while 5 cases contained a large majority of typically hormone-insensitive ones. The remaining 4 cases contained a relatively similar proportion of typically hormone-sensitive and insensitive cell nuclei. The quantitative chromatin pattern description thus made it possible to characterize the hormone-sensitivity level in PBCs, whereas DNA ploidy level determination did not enable any such characterization to be carried out. The chromatin pattern assay described here, which enables hormone-sensitive pregnancy-associated breast cancers to be identified from hormone-insensitive ones independently from biochemical assays, should help the physician regarding therapy adaptation.

Lectin histochemistry of astrocytic tumors and in vitro characterization of lectin-induced modifications on the proliferation of the SW1088, U373 and U87 human astrocytic cell lines

The role of lectins as biosignalling molecules or as markers of human astrocytic tumors remains relatively unexplored. The aim of the present work is to investigate (1) whether or not human astrocytic tumors express specific glycans, evidenced experimentally by means of lectin histochemistry, and (2) whether, in turn, these lectins can significantly modulate astrocytic tumor cell proliferation. Using a cell image processor, we therefore began by quantitatively measuring the histochemical binding pattern of 5 lectins (WGA, PNA, PHA-L, GSA-IA4 and Con A) in 5 astrocytomas, 5 anaplastic astrocytomas and 5 glioblastomas. Secondly, we measured the influence of these 5 lectins on the proliferation of 3 astrocytic tumor cell lines (SW1088, U373 and U87) growing in vitro as monolayers. Cell proliferation was assessed by means of the colorimetric MTT assay. The histochemical lectin staining markedly varied intra- and inter-group. However, some constant results were obtained. Indeed, the staining increased markedly from GSA-IA4 and PHA-L through WGA and PNA to ConA in the three histopathological groups. The assessment of cell proliferation demonstrated that WGA, Con A and PHA-L very significantly decreased proliferation in the 3 astrocytic cell lines in a dose-dependent manner. Astrocytic tumor cells in the confluent growth phase were less sensitive to the WGA, Con A and PHA-L lectin-induced effects than cells in the log growth phase. The GSA-IA4 and PNA lectins had globally very weak effects on the proliferation of the astrocytic tumor cell lines. Increasing the fetal calf serum from 1% to 10% in the culture media significantly antagonized the WGA-, Con A- and PHA-L-induced cell proliferation decrease in the 3 astrocytic cell lines. In conclusion, the present data strongly suggest that some lectins (including WGA, Con A and PHA-L) significantly influence the proliferation of astrocytic tumor cells.