Characterization of ligands for galectins, natural galactoside-binding immunoglobulin G subfractions and sarcolectin and also of the expression of calcyclin in thyroid lesions

The purpose of this study was to characterize ligands for galectins, natural galactoside-binding immunoglobulin G subfractions and sarcolectin and also the expression of calcyclin in various benign and malignant thyroid lesions. The extent of the binding of eight glycochemical probes was quantitatively assessed using computer-assisted microscopy on 76 thyroid lesions including 10 not-otherwise-specified multinodular goiters (S_MNG), 11 multinodular goiters with adenomatous hyperplasia (AH_MNG), 8 normomacrovesicular (NM_ADE) and 12 microvesicular (MIC_ADE) adenomas, and 9 papillary (P_CAR), 10 follicular variants of papillary (FvarP_CAR), 7 follicular (F_CAR) and 9 anaplastic (A_CAR) carcinomas. The 8 histochemical probes included 5 animal lectins (including galectins and sarcolectin), 1 polyclonal antibody (raised against calcyclin) and 2 immunoglobulin G subfractions from human serum with selectivity to alpha- and beta-galactosyl residues. The results show that multinodular goiters with adenomatous hyperplasia exhibited histochemical characteristics intermediate to those of normal multinodular goiters and microvesicular adenomas. Normomacrovesicular adenomas behaved very distinctly from microvesicular ones. Microvesicular adenomas were more closely related to differentiated thyroid carcinomas than any other type of benign thyroid lesions of epithelial origin. Papillary and follicular carcinomas seemed to represent the two extremes of the same biological entity with the follicular variant of the papillary carcinoma serving as a biological link between these two extremes. Anaplastic carcinomas behaved in a significantly different manner when compared to the differentiated forms of thyroid carcinomas. The results suggest that the patterns of expression of the glycoconjugates investigated in the present study may constitute useful tools for characterizing lesions in the human thyroid.

Homocamptothecin, an E-ring-modified camptothecin, exerts more potent antiproliferative activity than other topoisomerase I inhibitors in human colon cancers obtained from surgery and maintained in vitro under histotypical culture conditions

Topoisomerase I (Topo I) is overexpressed in cancer colon tissues compared with normal colon tissues. Several anti-Topo I inhibitors are already successfully used in the clinic. We illustrate here the antiproliferative activity of a new class of Topo I inhibitors, i.e., E-ring-modified camptothecins with enhanced lactone stability (L. Lesueur-Ginot et al., Cancer Res., 59: 2939-2943, 1999). Forty-three human colon cancers were obtained from surgical resection and maintained under organotypical culture conditions for 48 h. Cell proliferation was assessed in these ex vivo tumor tissue cultures by tritiated thymidine autoradiography. As a validation of the methodology, we first analyzed in our model the antiproliferative activity of two clinically active topoisomerase II (Topo II) inhibitors, Adriamycin and etoposide, which are not active for colon cancers; and three Topo I inhibitors, camptothecin (CPT) and two clinically active compounds (especially for colon cancers), i.e., topotecan and the active metabolite of irinothecan, SN-38. We then compared the antiproliferative activity of CPT, topotecan, and SN-38 against those of two investigational E-ring-modified camptothecins, i.e., BN80245 and BN80915. Three concentrations (1, 10, and 100 nM) were studied for each compound. The results indicate that the three Topo I inhibitors used as references, i.e., CPT, irinothecan, and SN-38, were much more active than the two Topo II inhibitors, i.e., Adriamycin and etoposide, with SN-38 being the most efficient. The two investigational compounds BN80245 and BN80915 exerted higher antiproliferative activity than the three anti-Topo I reference compounds, with the highest activity observed for BN80915.

Improving accuracy in the grading of renal cell carcinoma by combining the quantitative description of chromatin pattern with the quantitative determination of cell kinetic parameters

The determination of grade and stage in renal cell carcinomas (RCCs) often fails to predict the actual clinical outcome for individual patients. The aim of the present work was to investigate whether it is possible to significantly improve the prognostic accuracy of the grading system by using the combination of two independent computer-assisted microscopy techniques. The first technique relates to the quantitative description of morphonuclear and nuclear DNA content features by means of the image analysis of Feulgen-stained cell nuclei, and the second quantitatively characterizes tumor growth by means of different cell kinetic parameters. These parameters consist of a duplication of a time-related parameter determined by means of the technique of using silver-stained proteins in interphase nucleolar organizer regions (AgNOR), a proliferation index determined by means of MIB-1 immunohistochemistry, and an apoptotic index determined by means of the terminal dUTP nick end labeling technique. The prognostic value of these quantitative features was investigated in a series of 60 RCCs. The quantitative analysis of Feulgen-stained nuclei made it possible to identify subgroups of patients with significantly different prognoses in both grade II and grade III RCCs. We labeled the RCCs associated with the most favorable prognoses as grade II- and III- and those with the least favorable ones as grade II+ and III+. The two most important kinetic variables to identify patients with different clinical outcomes were the MIB-1 index and the mean AgNOR area in the MIB-1-positive cells. Three significantly different survival curves were obtained for the 53 grade II and III RCC patients. Our results show that conventional RCC grading can be significantly improved by the quantitative analysis of Feulgen-stained nuclei, by cell kinetic parameter determination, and, more importantly, by combining the proliferation index with the mean AgNOR area parameter.

Big prolactin 60 kDa is overexpressed in salivary glandular epithelial cells from patients with Sjögren's syndrome

Characterization of endogenous synthesis of prolactin (PRL) proteins and their cellular localization in labial salivary glands of patients with Sjogren's syndrome (SS) were achieved. PRL, PRL-receptors (PRL-R), and S100A6 protein were detected by immunohistochemistry. In situ prolactin synthesis was investigated in controls and SS patients by ex vivo incubation of minor salivary glands biopsies and immunoprecipitation assay. Increased PRL-immunoreactivity was found in cytoplasmic acinar epithelial cells in SS patients compared with normal subjects. PRL-R was distributed only in ductal epithelial cells in which S100A6 protein (a PRL-R-associated protein) was also present. PRL, PRL-R, or S100A6-immunoreactivity was not detected in infiltrating mononuclear cells. Immunoprecipitation demonstrated that PRL synthesis occurred in minor salivary glands with increased synthesis of two distinct PRL-like proteins (one major band at 60 kDa and a minor at 16 kDa) in SS glands compared with normal glands. Expression of PRL gene was demonstrated in SS salivary glands using RT-PCR. A positive correlation was found between the presence of PRL-like proteins in acinar epithelial cells of SS patients and clinical extraglandular manifestations. The presence of anti-Ro and anti-La antibodies also positively correlated with a higher percentage of PRL in acinar epithelial cells. In conclusion, PRL-like proteins are synthetized and overexpressed in glandular epithelial cells of labial salivary glands from SS patients and correlate with the aggressiveness of the disease.

Differential expression of S100 calcium-binding proteins characterizes distinct clinical entities in both WHO grade II and III astrocytic tumours

The computer-assisted microscopic analysis of Feulgen-stained nuclei enabled us to identify two subgroups of astrocytomas (WHO grade II) and two subgroups of anaplastic astrocytomas (WHO grade III) with significantly distinct clinical outcomes (Decaestecker et al. Brain Pathol 1998; 8: 29-38). The astrocytomas labelled in the present study as typical (TYP-ASTs) behaved clinically like real astrocytomas while atypical astrocytomas (ATYP-ASTs) behaved similarly to anaplastic astrocytomas. The anaplastic astrocytomas that we labelled as typical (TYP-ANAs) behaved clinically like anaplastic astrocytomas while atypical ones (ATYP-ANAs) behaved like glioblastomas. In the present study, we investigate whether some biological characteristics could be evidenced across these four groups of TYP- and ATYP-ASTs and TYP- and ATYP-ANAs. The data show that the levels of expression (immunohistochemically assayed and quantitatively determined by means of computer-assisted microscopy) of vimentin, the glial fibrillary acidic protein and the platelet-derived growth factor-alpha did not differ significantly across these four groups of astrocytic tumours. The level of cell proliferation (determined by means of both the anti-proliferating cell nuclear antigen and the anti-MIB-1 antibodies; P < 0.001 to P < 0.0001) differed very significantly between the astrocytomas and anaplastic astrocytomas, but not between the typical and atypical variants identified in each group. In sharp contrast, the levels of expression of the S100A3 and S100A5 proteins differed markedly in the solid tumour tissue in relation to the astrocytic tumour types and grades. In addition, while the levels of expression of S100A6 did not change in the astrocytic tumour tissue in relation to histopathological grade, the levels of expression of this S100 protein (but not those of S100A3 and S100A5) differed markedly in the blood vessel walls according to whether these vessels originated from low- or high-grade astrocytic tumours.

Characterization of TNP-470-induced modifications to cell functions in HUVEC and cancer cells

The aim of the present work is to characterize (both in vitro and in vivo) the influence of TNP-470 on different cell functions involved in angiogenesis and, more particularly, on endothelial cell growth, cell migration and vessel formation. In addition, a possible direct anti-tumor activity was investigated. To this end, we made use in vitro of human umbilical cord endothelial vein (HUVEC) cells and two human cancer cell lines. The TNP-470 effects on the growth of cancer cell lines were compared to those of Taxol (an inhibitor of microtubule depolymerization), a cytotoxic reference which also displays strong antiogenic activity at low (non-toxic) doses. The in vitro effects were characterized on the mouse mammary MXT adenocarcinoma, on which we also characterized the influence of three clinically active anti-tumor compounds (as cytotoxic references). The purpose of this part of the study was to determine the actual TNP-470-related anti-tumor activity and to evaluate the possible toxic side-effects at the doses at which this compound induces tumor growth inhibition. These investigations were completed by analyzing the TNP-470 effects on HUVEC cell motility and in vitro and in vivo vessel formation. The results show that in vitro, TNP-470 inhibited the growth not only of HUVEC, but also of neoplastic cells. Furthermore, TNP-470 clearly inhibited in vitro endothelial cell motility (p<10(-5)). However, it had only a minor effect (p=0.02) on the formation of HUVEC cell networks on Matrigel(R). In vivo, TNP-470 was able to inhibit tumor growth (on the MXT model) at a dose (50 mg/kg) associated with toxic side-effects. Histological examination showed a significant inhibition of vessel formation (p<0.001) at high (toxic) and intermediary (non-toxic) doses (50 and 20 mg/kg). However, we also observed that TNP-470 stimulated lymphocyte proliferation. Thus, care must be taken with the TNP-470 compound in combination with other anti-tumoral agents in order to avoid certain unfortunate clinical complications.

The levels of expression of galectin-1, galectin-3, and the Thomsen-Friedenreich antigen and their binding sites decrease as clinical aggressiveness increases in head and neck cancers

BACKGROUND

The aim of this study was to investigate whether an increase in malignancy level is accompanied by significant modifications of the expression of galectin-1, galectin-3, and Thomsen-Friedenreich antigen (T antigen) as well as the expression of binding sites for these three markers in head and neck squamous cell carcinomas (HNSCCs).

METHODS

Immunohistochemical and glycohistochemical staining reactions were carried out with antibodies, labeled lectins, and a custom-made neoglycoprotein on the basis of histologic slides from a retrospective series of 40 normal and 75 HNSCC formalin fixed, paraffin embedded tissues, and were quantitatively described with the aid of computer-assisted microscopy.

RESULTS

Whatever the histologic type, the epithelial tissues in HNSCC exhibited very significantly (P < 0.01 to P < 0. 0001) lower amounts of galectin-1, galectin-3, and T antigen and their respective binding sites than their corresponding normal counterparts. The tumors of the larynx differed very significantly (P < 0.0001 to P < 0.000001) from all the other tumor types. A loss of differentiation in the HNSCCs is accompanied first by the loss of expression of galectin-3 and galectin-3-reactive sites and then by that of the T antigen and its binding site(s). The opposite feature was observed when the parameters associated with the TNM classification were taken into account. The negative lymph node HNSCCs could be distinguished (P = 0.02) from the positive lymph node HNSCCs on the basis of a loss of galectin-3 expression. The modifications occurring in the extent of expression of galectin-1 and galectin-1-reactive sites were relatively marginal in comparison with those observed for galectin-3-dependent and T- antigen-dependent staining.

CONCLUSIONS

The decrease in the extent of expression of galectin-3 and galectin-3-reactive sites, T antigen and T antigen-binding sites, and, to a lesser extent, galectin-1 and galectin-1-reactive sites correlates significantly with an increasing level of clinically detectable HNSCC aggressiveness.

Computer-assisted analysis of epiluminescence microscopy images of pigmented skin lesions

BACKGROUND

Epiluminescence microscopy (ELM) is a noninvasive clinical tool recently developed for the diagnosis of pigmented skin lesions (PSLs), with the aim of improving melanoma screening strategies. However, the complexity of the ELM grading protocol means that considerable expertise is required for differential diagnosis. In this paper we propose a computer-based tool able to screen ELM images of PSLs in order to aid clinicians in the detection of lesion patterns useful for differential diagnosis.

METHODS

The method proposed is based on the supervised classification of pixels of digitized ELM images, and leads to the construction of classes of pixels used for image segmentation. This process has two major phases, i.e., a learning phase, where several hundred pixels are used in order to train and validate a classification model, and an application step, which consists of a massive classification of billions of pixels (i.e., the full image) by means of the rules obtained in the first phase.

RESULTS

Our results show that the proposed method is suitable for lesion-from-background extraction, for complete image segmentation into several typical diagnostic patterns, and for artifact rejection. Hence, our prototype has the potential to assist in distinguishing lesion patterns which are associated with diagnostic information such as diffuse pigmentation, dark globules (black dots and brown globules), and the gray-blue veil.

CONCLUSIONS

The system proposed in this paper can be considered as a tool to assist in PSL diagnosis.

Sialic acid residues in the labial salivary glands from Sjögren's syndrome patients

OBJECTIVE

To investigate the composition and expression of sialic acid in the labial salivary glands (LSG) in Sjögren's syndrome (SS).

METHODS

LSG of 19 patients with primary SS (n = 11) or secondary SS (n = 8) were studied. Specimens from 7 healthy women served as controls. Computer-assisted microscopy was employed to quantitatively determine the percentage of positive structures, the staining intensity and the heterogeneity for the 4 biotinylated plant lectins Tritricum vulgaris L. (WGA), Maackia amurensis (MAA), Sambucus nigra (SNA) and Canavalia ensiformis L. (Con A).

RESULTS

In the acini there was a significant decrease in the staining heterogeneity of WGA in SS compared to controls; the same was observed with respect to MAA staining in the connective tissue and extralobular ducts. In the intralobular ducts, primary SS differed from normal and secondary SS mainly in terms of a decrease in the percentage of positively labeled MAA tissue. In addition, Con A stained acinar cells were significantly more numerous in secondary SS compared with primary SS.

CONCLUSION

Differences in the degree of glycoconjugate sialylation were found in SS labial salivary glands, and may play a role in the disease process.

Determination of the levels of expression of sarcolectin and calcyclin and of the percentages of apoptotic but not proliferating cells to enable distinction between recurrent and nonrecurrent cholesteatomas

OBJECTIVES

To investigate in a series of cholesteatomas 1. whether subgroups of cholesteatomas with specific proliferative/apoptotic features exhibit distinct differentiation markers and 2. whether these different subgroups identified at the biological level relate to specific groups of clinically identified cholesteatomas.

STUDY DESIGN

Analysis of 55 cholesteatomas resected by the same surgeon, by means of canal wall up and canal wall down surgical procedures.

METHODS

Two differentiation markers were used: biotinylated sarcolectin (to identify sarcolectin-binding sites) and a monoclonal antibody directed against calcyclin (which is the S100A6 protein). The growth pattern in cholesteatomas was characterized at three distinct levels: 1. the cell proliferation level determined by means of the MIB-1 antibody, which enables the Ki-67 cell-cycle-related antigen to be identified on archival material; 2. the apoptosis level determined by means of the in situ labeling of nuclear DNA fragmentation (TUNEL staining); and 3. the p53 tumor suppressor gene-related product determined by means of p53 immunohistochemistry.

RESULTS

The cholesteatomas that exhibited the highest proportion of apoptotic cells were those which exhibited the highest level of sarcolectin-binding sites (i.e., sialic acids). In contrast, the cholesteatomas exhibiting the lowest level of both proliferation and apoptosis showed the highest level of calcyclin. Recurrent cholesteatomas can be identified from nonrecurrent ones on the basis of three features, namely, the level of apoptotic cells, the way in which the apoptotic cells are distributed (i.e., homogeneously vs. heterogeneously), and the percentage of calcyclin-positive cells.

CONCLUSIONS

The present data emphasize the existence of distinct subgroups of cholesteatomas identifiable at both cell kinetic and differentiation levels. Some of the biological variables used here to identify distinct biological subgroups of cholesteatomas in turn enabled some biological variables to be identified, so making it possible to classify the cholesteatomas in terms of recurrence versus nonrecurrence.

Grading dysplasia in colorectal adenomas by means of the quantitative binding pattern determination of Arachis hypogaea, Dolichos biflorus, Amaranthus caudatus, Maackia amurensis, and Sambucus nigra agglutinins

The current study deals with the setting up of a new tool that enables the benign versus the malignant nature of colorectal adenomas to be determined accurately. The 2 objectives are to determine (1) whether adenomas should, or should not, be included in a 2- or a 3-tier grading system, and (2) whether severe dysplasias and carcinomas in situ share common or different biological characteristics. The levels of expression of different types of glycoconjugates were characterized in a series of 166 colorectal specimens, including 14 normal, 90 dysplastic, and 62 cancerous cases. The glycoconjugate expressions were demonstrated for 5 lectins, namely, Arachis hypogaea (PNA), Dolichos biflorus (DBA), Amaranthus caudatus (ACA), Maackia amurensis (MAA) and Sambucus nigra (SNA). The glycoconjugates demonstrated by these 5 lectins belong to the family of the Thomsen-Friedenreich antigens. The binding patterns of the 5 lectins were quantitatively determined by means of computer-assisted microscopy. The quantitative data were submitted to discriminant analyses. Our results show that the specific glycochemical staining patterns could be identified unambiguously and without misclassification between benign (normal and low dysplasia) and malignant (ie, either as moderate/severe dysplasia, carcinoma in situ, or cancer) cases. The data also strongly suggested that (1) dysplasias seem to be distinguishable in 2 instead of 3 groups, that is, low versus moderate/severe (high); and (2) moderate/severe dysplasias are biologically distinct from carcinomas in situ. The methodology developed can be applied directly in routine diagnosis to identify moderate/severe dysplasia specimens already exhibiting features common to carcinomas, and which therefore should be treated consistently in view of the fact that our data strongly suggest that most moderate/severe dysplasias are still benign, whereas carcinomas in situ are real carcinomatous lesions.

A pilot study for identifying at risk thyroid lesions by means of a decision tree run on clinicocytological variables

Fine-needle aspiration biopsy (FNAB) is safe, inexpensive, minimally invasive, and highly accurate in the diagnosis of nodular diseases of the thyroid. However, FNAB does not provide a reliable benign versus malignant diagnosis for 100% of the cases analysed. It is possible to increase the accuracy of the cytological diagnosis by means of information contributed by different clinical variables. In the present study we evaluate the diagnostic value of 10 variables in addition to FNAB on a series of 218 specimens for which we obtained histological diagnoses including 37 cancers (17%). The diagnostic information contributed by these variables was analyzed by means of the Decision Tree technique, an artificial intelligence-related method which forms part of the Supervised Learning algorithms. The results show that Decision Trees enable some subpopulations of patients with uncertain FNAB results to be characterized.

Galectin-1 and galectin-3 binding pattern expression in renal cell carcinomas

We studied 2 families of molecules whose role remains uncharacterized or obscure in the progress of renal cell carcinoma (RCC): galectins, a major class of glycoproteins, and the Thomsen-Friedenreich (T) antigen. We characterized the level of expression of galectin-1 and galectin-3 and their respective binding sites in a series of 74 RCCs. We also characterized the level of expression of laminin, a natural ligand for galectins. Finally, we characterized the level of T antigen expression and the T antigen binding sites. All levels of expression were quantitatively determined by using computer-assisted microscopy on immunohistochemically or glycohistochemically stained slides. A small concentration of galectin-1 binding sites or a large concentration heterogeneity of galectin-3 can be associated with unfavorable prognoses for patients with grade II or III RCCs. In contrast, T antigen and T antigen binding sites revealed no change across the 2 RCC groups that exhibited different clinical outcomes. We established discriminant scores that permitted a clear distinction between the 2 RCC groups analyzed. Modifications to the expression of galectin-1 and galectin-3, but not of T antigen, parallel an increase in RCC aggressiveness. Galectins represent a family of molecules with a meaningful role in RCC progression.

Galectin-3 and galectin-3-binding site expression in human adult astrocytic tumours and related angiogenesis

Using computer-assisted microscopy, the present work aimed to quantitatively characterize the level of the histochemically detectable expression of galectin-3 and galectin-3-binding sites in sections of a series of 84 astrocytic tumours (including 22 grade II, 21 grade III and 41 grade IV specimens) and seven non-tumoural specimens used as controls. The presence of galectin-3 and reactive sites for this lectin were monitored by means of a specific polyclonal anti-galectin-3 antibody (aGal3) and biotinylated galectin-3 (Gal3), respectively. The pattern of expression of galectin-3-binding sites is compared to the pattern of expression of laminin (a potential galectin-3 ligand) revealed using a biotinylated anti-laminin antibody (aLam). Three variables quantitatively characterizing histochemical staining reactions were evaluated by means of computer-assisted microscopy for each of the 3 probes under study (aGal3, Gal3 and aLam). The labelling index (LI) is the percentage of tissue area specifically stained by a histochemical probe. The mean optical density (MOD) denotes staining intensity. The concentration heterogeneity (CH) feature expresses the concentrational spread of individual fields. The data obtained in the present study show that: (i) white matter of a non-tumoural brain expresses galectin-3 (and also galectin-3-binding sites); (ii) the level of galectin-3 expression significantly decreases in the majority of tumour astrocytes from low to high grade astrocytic tumours; while (iii) some tumour cell clones expressing high amounts of galectin-3 emerged with increasing levels of malignancy; and (iv) the level of accessible galectin-3-binding sites was apparently not heavily modified in the course of malignancy progression. In conclusion, the results obtained in the present study show that human astrocytic tumours are very heterogenous in their galectin-3 levels of expression. If high levels of galectin-3 determine the invasiveness potential of a tumour cell, then within a heterogenous tumour the presence of even a small, but actively proliferating number of tumour cell clones expressing high levels of galectin-3 can be expected to lead to tumour invasiveness.

Quantitative glycohistochemical characterization of normal nasal mucosa, and of single as opposed to massive nasal polyps

A series of 41 nasal polyps (23 single and 18 massive) and 6 normal nasal mucosa specimens was glycohistochemically investigated. Five plant lectins were used, i.e., the peanut agglutinin (PNA), the wheat germ agglutinin (WGA), the gorse seed agglutinin (UEA-I), the Maackia amurensis agglutinin (MAA), and the elderberry bark agglutinin (SNA). A neoglycoconjugate and 2 animal lectins (CL-14 and CL-16) were also used. Three quantitative features were calculated by means of computer-assisted microscopy: the percentage of tissue area specifically stained by the histochemical probe, the staining intensity, and the heterogeneity level of the staining distribution. The results show that with respect to sialic acid-glycoprotein binding characteristics as determined by SNA, MAA, and WGA probes, the normal nasal mucosa differed markedly (p<.00001) from the polyposal one. The single nasal polyps exhibited glycohistochemical characteristics that differed markedly (p = .0004) from those exhibited by the massive ones. These differences related mainly to the UEA-I, PNA, and the Thomsen-Friedenreich antigen-exposing neoglycoprotein binding characteristics. In conclusion, the present study shows unambiguously that polyposal mucosa, whether of the single or the massive type, exhibits markedly distinct glycohistochemical characteristics when compared to normal nasal mucosa, and that single nasal polyps also differ markedly from massive ones.

Critical roles for IL-4, IL-5, and eosinophils in chronic skin allograft rejection

C57BL/6 mice injected with the 145-2C11 anti-CD3 mAb and grafted with MHC class II disparate bm12 skin develop a chronic rejection characterized by interstitial dermal fibrosis, a marked eosinophil infiltrate, and an obliterative intimal vasculopathy. Because these changes occur in the absence of alloreactive antibodies, we examined the contribution of cytokines in their pathogenesis. Chronically rejected grafts showed a marked accumulation of both IL-4 and IL-5 mRNA. Mixed lymphocyte reaction experiments established that mice undergoing chronic rejection were primed for IL-4, IL-5, and IL-10 secretion. In vivo administration of anti-IL-4 mAb completely prevented allograft vasculopathy as well as graft eosinophil infiltration and dermal fibrosis. Injection of anti-IL-5 mAb or the use of IL-5-deficient mice as recipients also resulted in the lack of eosinophil infiltration or dermal fibrosis, but these mice did develop allograft vasculopathy. Administration of anti-IL-10 mAb did not influence any histologic parameter of chronic rejection. Thus, in this model, IL-4- and IL-5-mediated tissue allograft eosinophil infiltration is associated with interstitial fibrosis. IL-4, but not eosinophils, is also required for the development of obliterative graft arteriolopathy.

Homocamptothecin, an E-ring modified camptothecin with enhanced lactone stability, retains topoisomerase I-targeted activity and antitumor properties

Homocamptothecin (hCPT) is a semisynthetic analogue of camptothecin (CPT) with a seven-membered beta-hydroxylactone resulting from the insertion of a methylene spacer between the alcohol moiety and the carboxyl function of the naturally occurring six-membered alpha-hydroxylactone of CPT. This E-ring modification provides a less reactive lactone with enhanced stability and decreased protein binding in human plasma. Biological testing against CPT revealed that, instead of being detrimental, the modified lactone of hCPT has a positive impact on topoisomerase I (Topo I) poisoning properties. In vitro tests showed hCPT to fully conserve the ability to stabilize Topo I-DNA cleavage complexes and to stimulate a higher level of DNA cleavage than CPT. A similar trend toward improvement was also observed in antiproliferative assays with human tumor cell lines (including cells overexpressing P-glycoprotein). In two distinct in vivo models, using L1210 murine leukemia or human colon carcinoma HT29, hCPT was found to be more efficacious than CPT. The slow, but irreversible, hydrolysis of hCPT, instead of the fast equilibrium of CPT, may account for its good in vivo activity. Overall, these results provide evidence that a highly reactive lactone is not a requisite for the Topo I-mediated antitumor activity of CPT analogues, and that hCPT is an interesting pharmacological tool with improved solution behavior as well as a promising new template for the preparation of more efficacious Topo I poisons.

The influence of L-triiodothyronine, L-thyroxine, estradiol-17beta, the luteinizing-hormone-releasing hormone, the epidermal growth factor and gastrin on cell proliferation in organ cultures of 35 benign and 13 malignant human thyroid tumors

PURPOSE

To characterize the influence of six factors on human thyroid tissues at the cell-proliferation level. These six factors were the epidermal growth factor (EGF), the luteinizing-hormone-releasing hormone (LHRH), triiodothyronine, thyroxine, estradiol and gastrin.

METHODS

Forty-eight human thyroid specimens were obtained from surgical resection and maintained alive for 48 h ex vivo (in vitro) under organotypic culture conditions. These specimens comprised 35 benign cases (17 multinodular goiters and 18 adenomas) and 13 cancers. Cell proliferation in the control and treated conditions (at a 5 nM dose) was assessed by means of the thymidine labeling index, which enables the percentage of cells in the S phase of the cell cycle to be determined in accordance with autoradiographic procedures.

RESULTS

The results show that, of the six factors tested here, EGF significantly (P < 0.05 to P < 0.001) increased cell proliferation in the greatest number of cancers as compared to what happened with the remaining five. Each of these six factors significantly increased or decreased proliferative cell activity in some 10%-30% of the cases under study.

CONCLUSIONS

Triiodothyronine, thyroxine, LHRH and gastrin may increase or decrease cell proliferation in human thyroid tissues, whether benign or malignant, to the same extent as other hormones and/or growth factors such as thyrotropin, EGF, insulin-like growth factor 1, transforming growth factor beta1 and estradiol the effects of which on thyroid cell proliferation are already well documented in the literature.

In vitro influence of lectins and neoglycoconjugates on the growth of three human sarcoma cell lines

PURPOSE

The aim of our study is to investigate the in vitro effects of plant lectins, galectins and neoglycoconjugates on the proliferation of three human sarcoma cell lines.

METHODS

Proliferation was assessed by means of the tetrazolium derivative reduction (MTT) assay. In addition, glycohistochemistry was used to make visible the plant-lectin-specific binding sites; the intensity of the lectin binding pattern was quantified by means of image analysis.

RESULTS

Depending on the cell lines, the staining intensity and the percentage of labelled cells were different. With respect to growth modulation, the cell lines also responded differently to the probes used. Besides a predominant inhibitory effect elicited by the probes at 50 microg/ml, dose-dependent effects, including growth stimulation, were detectable in several instances. These effects relate to the animal galectins tested and several neoglycoconjugates, e.g. the lactose- and blood-group-A-trisaccharide-bearing probes.

CONCLUSIONS

Endogenous lectins and lectin-reactive cellular glycoconjugates can apparently affect the regulation of the growth of human sarcoma cells. We suggest that these results are relevant for further histopathological monitoring in correlation with prognosis and in vitro assays to reveal possible clinical applications.

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.

Galectin fingerprinting in tumor diagnosis. Differential expression of galectin-3 and galectin-3 binding sites, but not galectin-1, in benign vs malignant uterine smooth muscle tumors

Cell-matrix interactions are governed by a distinct set of proteins, with 2 nonintegrin laminin-binding proteins, galectin-1 and galectin-3, providing 1 aspect. The expression patterns of laminin and the 2 galectins and galectin binding sites were quantitatively determined by means of computer-assisted microscopy with the aim of differentiating between 16 leiomyomas and 10 leiomyosarcomas of the uterus. Three quantitative variables were computed for each of the 5 histochemical markers: labeling index, which describes the percentage of tissue area specifically stained by a given marker; mean optical density which reflects the concentration of the marker; and concentrational heterogeneity, which characterizes the degree of heterogeneity of the marker distribution in the tumor tissue areas. The results reveal evident differences in the galectin-3-related parameters in the 2 tumors groups. Whereas the concentration of galectin-3 binding sites was significantly (P = .01) weaker in the leiomyosarcomas than in the leiomyomas, the percentages of tumor tissue expressing galectin-3 (P = .02) and its binding sites (P = .002) were significantly higher in the leiomyosarcomas than in the leiomyomas. Although significantly (P = .02) higher, the concentration of laminin was more heterogeneously distributed (P = .01) in the leiomyosarcomas than in the leiomyomas. In contrast, the levels of expression of galectin-1 and its accessible binding sites remained similar for both the leiomyomas and the leiomyosarcomas. Finally we document how the levels of expression of galectin-3 and its binding sites can be of assistance in reliably differentiating leiomyomas from leiomyosarcomas.

In vitro motility evaluation of aggregated cancer cells by means of automatic image processing

BACKGROUND

Set up of an automatic image processing based method that enables the motility of in vitro aggregated cells to be evaluated for a number of hours.

METHODS

Our biological model included the PC-3 human prostate cancer cell line growing as a monolayer on the bottom of Falcon plastic dishes containing conventional culture media. Our equipment consisted of an incubator, an inverted phase contrast microscope, a Charge Coupled Device (CCD) video camera, and a computer equipped with an image processing software developed in our laboratory. This computer-assisted microscope analysis of aggregated cells enables global cluster motility to be evaluated. This analysis also enables the trajectory of each cell to be isolated and parametrized within a given cluster or, indeed, the trajectories of individual cells outside a cluster.

RESULTS

The results show that motility inside a PC-3 cluster is not restricted to slight motion due to cluster expansion, but rather consists of a marked cell movement within the cluster.

CONCLUSIONS

The proposed equipment enables in vitro aggregated cell motility to be studied. This method can, therefore, be used in pharmacological studies in order to select anti-motility related compounds. The compounds selected by the equipment described could then be tested in vivo as potential anti-metastatic.

D-mannose and N-acetylglucosamine moieties and their respective binding sites in salivary glands of Sjögren's syndrome

OBJECTIVE

Sjögren's syndrome (SS) is an autoimmune exocrinopathy. The mannose binding lectin (MBL), a pluripotent molecule of the innate immune system, is involved in the pathogenesis of autoimmune diseases. We investigated whether specific ligands for MBL and MBL related structures could be reliable markers in cases of SS.

METHODS

The labial salivary glands of 19 patients fulfilling the diagnostic criteria for primary (n=11) and secondary SS (n=8) were studied. Seven healthy women served as controls. Computer assisted microscopy was employed to determine quantitatively the percentage of positive structures (acini, ducts, and interlobular connective tissue), the staining intensity, and the level of staining heterogeneity for 4 glycohistochemical probes including wheat germ agglutinin and concanavalin (Con A) as lectins, and mannose and N-acetylglucosamine as parts of neoglycoproteins. The data were evaluated by discriminant analysis.

RESULTS

The data strongly suggest that MBL related structures, if not MBL itself, could play distinct roles in the pathogenesis of primary versus secondary SS. Further, quantitative determination of the level of expression of D-mannose and N-acetylglucosamine and their respective binding sites in labial salivary gland acini offers a powerful diagnostic tool for distinguishing primary from secondary SS.

CONCLUSION

In SS labial salivary glands, determination of the level of acceptor sites for wheat germ agglutinin, Con A, D-mannose, and N-acetylglucosamine provides information on the roles played by glycoforms in SS. The methodology and data described in this paper should provide pathologists with objective diagnostic markers for SS. Our results should enhance the biological understanding of this pathology.

Characterization of biological features and chemosensitivity of a new experimental lung metastasis model originating from the MXT mouse mammary adenocarcinoma

The present study shows how an original mouse metastatic lung model was established from the MXT mammary adenocarcinoma. This metastatic model was obtained by injecting the C/MET clone into the tail veins of B6D2F1 mice. The C/MET clone corresponds to one of eleven cell clones that were isolated in vitro from the MXT model. Of these 11 clones, only the C/MET leads to lung metastatic tumor development when injected i.v. into mice. Furthermore, the C/MET clone colonizes the lung only. The present data show that the C/MET metastatic model and the MXT parental line are weakly (if reference is made to the P388 leukemia model) sensitive to adriamycin, clyclophosphamide and etoposide. However, under specific experimental conditions, the chemosensitivity of the C/MET model can be significantly increased. The C/MET model therefore appears to be an interesting pharmacological tool to test new investigational agents with anti-tumor potentialities to lung metastases.

[Ret-protooncogene mutation, verified by molecular genetic methods, in a Hungarian MEN Type 2a family]

Multiple endocrine neoplasia Type 2 (MEN2) is a hereditary tumour syndrome characterized by the association of medullary thyroid cancer, phaeochromocytoma and hyperparathyroidism. It is inherited as an autosomal dominant trait. During the past few years the cloning of the gene responsible for the syndrome, the ret protooncogene, made the molecular genetic diagnosis of the disease possible. In this study we demonstrate the results of the MEN2 mutation analysis performed in three members of a Hungarian MEN2A family. The mutation analysis was carried out according to the method of Dr. W. Hoppner's Laboratory (Hamburg) that is the main centre for MEN2 genetic diagnosis in Germany. Two Members of the family are affected, one suffered from both medullary thyroid cancer and phaeochromocytoma, the other (the first patient's daughter) had only medullary thyroid cancer. We found a ret exon 11 codon 634 mutation, that resulted in the change of TGC to TAC, a cysteine-tyrosine amino acid exchange. We found no mutation in the youngest member of the family. This result is of great clinical significance, because the carrier status of this individual can thus be excluded and, therefore, there is no need for prophylactic thyroidectomy and further clinical screening tests. As molecular genetic diagnosis of MEN2 becomes possible, the uncertain clinical examinations used for MEN2 diagnosis seems to be less important.