The involvement of E6, p53, p16, MDM2 and Gal-3 in the clinical outcome of patients with cervical cancer.

High-risk human papilloma virus (HPV) is the leading cause of cervical cancer. HPV oncogenes are responsible for the development of malignancy, and the E6 oncoprotein that HPV expresses induces the degradation of tumour suppressor protein p53 (p53). This degradation leads to the upregulation of p16; however, unidentified proteins may also serve a role in the development and progression of cervical cancer. Therefore, the aim of the present study was to analyse the expression levels of E6, p53, p16, MDM2 proto-oncogene (MDM2) and galectin-3 (gal-3) in cervical cancer specimens. A total of 250 cervical cancer tissue slides were used. The expression of E6, p53, p16, MDM2 and gal-3 was analysed with immunohistochemical methods and a semi-quantitative scoring. SPSS software was used for the statistical evaluation of staining results and survival analysis of patients with cervical cancer. Cervical cancer specimens demonstrated significantly increased E6 staining with advanced T-status and increased International Federation of Gynecology and Obstetrics classification. E6, p53 and p16 demonstrated significantly different expression levels in squamous epithelial tissue compared with adenocarcinomas. MDM2 and gal-3 demonstrated positively correlated expression levels in cervical cancer. In addition, gal-3 expression was correlated with poor prognosis in p16-negative cases. A negative correlation between the expression of E6 and a mutated form of p53 was also identified in cervical cancer. p53 mutation was demonstrated to be common in cervical cancer, and gal-3 and MDM2 appeared to act in a combined manner in this type of tumour. As gal-3 is overexpressed in the cervical cancer tissue of patients with poor prognosis, the use of gal-3 inhibitors should be investigated in future studies.

Binding of galectin-1 to breast cancer cells MCF7 induces apoptosis and inhibition of proliferation in vitro in a 2D- and 3D- cell culture model.

BACKGROUND: Galectin-1 (gal-1) belongs to the family of ß-galactoside-binding proteins which primarily recognizes the Galß1-4GlcNAc sequences of oligosaccharides associated with several cell surface glycoconjugates. The lectin recognizes correspondent glycoepitopes on human breast cancer cells. Galectin-1 is expressed both in normal and malignant tissues. Lymphatic organs naturally possessing high rates of apoptotic cells, express high levels of Galectin-1. Furthermore galectin-1 can initiate T cell apoptosis. Binding of galectin-1 to trophoblast tumor cells presenting the oncofetal Thomsen-Friedenreich (TF) carbohydrate antigen inhibits tumor cell proliferation. In this study we examined the impact galectin-1 has in vitro on cell proliferation, apoptotic potential and metabolic activity of MCF-7 and T-47D breast cancer cells in dependence to their expression of the Thomsen-Friedenreich (TF) tumor antigen. METHODS: For proliferation and apoptosis assays cells were grown in presence of 10, 30 and 60 µg gal-1/ml medium. Cell proliferation was determined by a BrdU uptake ELISA. Detection of apoptotic cells was done by M30 cyto death staining, in situ nick translation and by a nucleosome ELISA method. Furthermore we studied the impact galectin-1 has on the metabolic activity of MCF-7 and T-47D cells in a homotypic three-dimensional spheroid cell culture model mimicking a micro tumour environment. RESULTS: Gal-1 inhibited proliferation of MCF-7 cells (strong expression of the TF epitope) but did not significantly change proliferation of T-47D cells (weak expression of the TF epitope). The incubation of MCF-7 cells with gal-1 raised number of apoptotic cells significantly. Treating the spheroids with 30 µg/ml galectin-1 in addition to standard chemotherapeutic regimes (FEC, TAC) resulted in further suppression of the metabolic activity in MCF-7 cells whereas T-47D cells were not affected. CONCLUSIONS: Our results demonstrate that galectin-1 can inhibit proliferation und metabolic cell activity and induce apoptosis in breast tumor cell lines with high expression levels of the Thomsen-Friedenreich (TF) antigen in monolayer and spheroid cell culture models.

Immunohistochemical Evaluation of the Role of p53 Mutation in Cervical Cancer: Ser-20 p53-Mutant Correlates with Better Prognosis.

BACKGROUND: Cervical cancer is driven by human papillomavirus virus-specific oncoprotein E6. E6 interacts with E3 ubiquitin-protein ligase, resulting in the proteolysis of p53 protein. The aim of this study was to analyze one TP53 mutation in patients with cervical cancer and to correlate it to prognosis. MATERIALS AND METHODS: A total of 248 paraffin-embedded tumor samples were stained for mutated p53 protein. The distribution and intensity of staining both in the nucleus and cytoplasm were evaluated with a semi-quantitative immunohistochemical score. RESULTS: A total of 66% of studied cervical carcinomas expressed the mutated p53 protein. The overall survival was better for patients expressing the mutated p53 protein in the nucleus. CONCLUSION: Interestingly, we found a very high mutation rate of TP53 in a cancer type where p53 is initially inactivated via E6 during the development of cervical cancer. An unexpected finding is the correlation of this mutation with better survival, possibly due to better response to therapy.

Effect of BSA-coated Superparamagnetic Iron Oxide Nanoparticles on Granulosa Cells.

BACKGROUND: Since superparamagnetic iron oxide nanoparticles (SPION) possess unique features, they provide a huge platform for medical applications, especially for cancer diagnosis and therapy (e.g. imaging, and drug targeting). However, heterogeneous effects on mammalian cells with regard to reproductive tissue are described. An experimental study was carried out to study the effects of SPIONs on both the expression of steroid hormone receptor and viability of granulosa cells, which play a key role in ovarian health and fertility. MATERIALS AND METHODS: Human granulosa cells were cultured in vitro and incubated with different concentrations of SPIONs. After 48 h, steroid receptor expression and cell viability were evaluated. RESULTS: Treatment of granulosa cells with SPIONs did not affect estrogen receptor ß1 or progesterone receptor-A expression and had no significant effect on cell viability. CONCLUSION: Nanoparticles precoated with bovine serum albumin (BSA) do not alter granulosa cell phenotype, whereas literature suggests that other nanoparticles induce apoptosis and reduce steroid receptor expression. Our data indicate an overall better outcome using SPIONs coated with BSA.

Expression of the Tumor-associated Mucin 1 Epitope Analyzed with the Humanized PankoMab-GEX™ Antibody in Malignant and Normal Tissues of the Head and Neck.

BACKGROUND: During neoplasia, glycosylation changes. In this setting, mucins, especially mucin 1 (MUC1), become carriers for oncofetal carbohydrates and relieve invasive growth. The recently described tumor-associated MUC1 epitope TA-MUC1 is primarily restricted to malignancies and is overexpressed in these tissues. The humanized monoclonal antibody PankoMab-GEX specifically recognizes TA-MUC1. MATERIALS AND METHODS: Laryngeal cancer specimens (n=125) and normal tissue of head and neck (n=7) were used in this study. Paraffin-embedded sections were incubated with PankoMab-GEX. Staining reaction was carried out using peroxidase (POD) labeling and diaminobenzidine (DAB). Breast cancer tissue was used as positive control and negative control used non-specific mouse IgM. Semi-quantitative evaluation by two independent double-blinded investigators, including a pathologist, used the immunoreactive score (IRS) of Remmele and Stegner. RESULTS: A total of 31 out of 125 laryngeal cancer specimens were classified as G1. Of these, 22 (71%) were completely negative for TA-MUC1, the remaining 9 showed very weak staining, with an IRS of 2. A total of 94 cases of cancer specimens were classified as G2 and G3; 34 of them were also negative, but 60 had an IRS of up to 9. All investigated normal tissue of the upper aerodigestive tract was completely negative for TA-MUC1. CONCLUSION: G1 tumors are completely negative or do not reach an IRS relevant range. The finding that G1 tumors are completely negative for TA-MUC1 or have IRS≤2 can be helpful for histopathological examination, especially concerning tumor grading. Therefore, this antibody holds great potential for use as a therapeutic antibody in laryngeal cancer.

Immunohistochemical Evaluation of E6/E7 HPV Oncoproteins Staining in Cervical Cancer.

BACKGROUND/AIM: High-risk human papillomavirus (HPV) subtypes (i.e. 16 and 18) lead to uterine cervical cancer as well as HPV-positive oropharyngeal cancer (OSCC), a form of head and neck cancer. The induction of HPV-induced cancer is driven by virus-specific oncoproteins E6 and E7. E6 protein of HPV types 16 and 18 interacts with the E3 ubiquitin protein ligase, resulting in ubiquitination and proteolysis of tumor protein p53. E7 inactivates retinoblastoma protein (Rb) by phosphorylation followed by an increase of free eukaryotic transcription factor E2F (E2F) in the cell. This leads to an increase of cyclin-dependent kinase inhibitor p16, that is used as an immunohistochemical marker of HPV-associated OSCC. Unfortunately, p16 is not exclusively increased by E7 oncoprotein in carcinogenesis. Therefore, the aim of this study was to develop an immunohistochemical approach for the direct detection of E6/E7 oncoproteins in uterine cervical cancer as well as in OSCC. MATERIAL AND METHODS: Paraffin sections of uterine cervical cancer and 130 were analyzed. Immunohistochemical staining protocols were evaluated with tissue slides from patients with cervical dysplasia (CIN III) and squamous epithelial carcinoma tissue with HPV infection. Liver and placental tissues were used as negative controls. E6-Specific antibody (Biorbyt) was used as primary antibody. The polymer staining method and diaminobenzidine were applied for further development. Panels of E7-specific antibodies were tested. Again, the polymer staining method and diaminobenzidine were applied for further development. RESULTS: E6-Specific antibody revealed specific and intense staining after pre-incubation of tissue slides with citrate buffer solution. Only the E7 antibody obtained from Chemicon showed intense and specific staining in patients with CIN III and squamous epithelial carcinoma tissue. Pre-incubation with proteinase K diminished non-specific reaction. CONCLUSION: Our results revealed a useful staining protocol for the immunohistochemical evaluation of E6/E7 oncoprotein expression in uterine cervical cancer, as well as in HPV-positive oropharyngeal cancer. Advantages of this method compared to mRNA in situ hybridization of E6/E7 are the much lower costs, as well as the broader applicability in pathological practice.

Methylation of the ER-alpha Promoter Is Influenced by its Ligand Estrogen in Osteosarcoma Cells SAOS-2 In Vitro.

BACKGROUND/AIM: The aggressive fast-growing osteosarcoma is the most common primary malignant bone tumor. The relevance of estrogen as a key player in bone metabolism and bone tumor is well-known. At the molecular level, estrogen activates the estrogen receptor α (ERα) as a natural ligand of this receptor. ERα acts as a transcription factor by binding to the "estrogen response element" (ERE) and regulates the expression of a various number of genes. Epigenetic processes, e.g. the methylation of the "cytosine-phosphatidyl-guanine (CpG) islands" can change the transcription of target genes and subsequently the protein expression. As DNA methylation is generally associated with gene transcription repression, up until now little is known about the ERα methylation in osteosarcoma cells. The aim of the present pilot study was to evaluate the methylation status of ERα in osteosarcoma cells SAOS-2 and MG 63 after stimulation with estrogen. MATERIALS AND METHODS: SAOS-2 and MG 63 cells were cultured in DMEM. After treatment with 10 nmol estrogen (E2) for 24 h, the expression of ERα was detected by immunocytochemistry (ICC). As controls we used untreated cells. Staining was evaluated semi-quantitatively by the immunoreactive score of Remmele and Stegner (IRS). To determine mRNA gene expression, extracted RNA was transcribed into c-DNA and a quantitative real-time-PCR (qRT-PCR) was carried out. The semi quantitative evaluation of the ERα mRNA was based on the 2(-ΔΔct) method using untreated cells as reference control. One microgram of each extracted genomic DNA sample was converted with bisulfite and a real-time methylation-specific PCR (rt-MSP) was performed. RESULTS: The estrogen-stimulated SAOS-2 cells showed a significant increase of ERα expression. A 7-fold up-regulation of ERα mRNA confirmed the results of immunocytochemistry. Methylation of the ERα promoter was not detected in treated cells. In contrast, we identified methylation of the ERα promoters in untreated cells. The staining of MG 63 cells showed a weak gain of ERα expression in the stimulated cells, as well as a weak increase of the ER-α mRNA (2-fold). Methylation of the ERα promoters was not detectable in either treated or untreated cells. CONCLUSION: The methylation status of ERα in osteosarcoma cells is affected by estrogen. These findings indicate that epigenetic changes of genomic DNA regulate ERα synthesis. Taken together, our results suggest that SAOS-2 cells can be an interesting model for further investigating ERα synthesis. In addition, the evaluation of ERα methylation in osteosarcoma specimens is in progress.

Genotoxicity of Superparamagnetic Iron Oxide Nanoparticles in Granulosa Cells.

Nanoparticles that are aimed at targeting cancer cells, but sparing healthy tissue provide an attractive platform of implementation for hyperthermia or as carriers of chemotherapeutics. According to the literature, diverse effects of nanoparticles relating to mammalian reproductive tissue are described. To address the impact of nanoparticles on cyto- and genotoxicity concerning the reproductive system, we examined the effect of superparamagnetic iron oxide nanoparticles (SPIONs) on granulosa cells, which are very important for ovarian function and female fertility. Human granulosa cells (HLG-5) were treated with SPIONs, either coated with lauric acid (SEONLA) only, or additionally with a protein corona of bovine serum albumin (BSA; SEON(LA-BSA)), or with dextran (SEON(DEX)). Both micronuclei testing and the detection of γH2A.X revealed no genotoxic effects of SEON(LA-BSA), SEON(DEX) or SEON(LA). Thus, it was demonstrated that different coatings of SPIONs improve biocompatibility, especially in terms of genotoxicity towards cells of the reproductive system.

Significance of the tumor protease cathepsin D for the biology of breast cancer.

Cathepsin D is a protease involved in the metastasis and angiogenesis of mammary carcinomas. This review analyzes the significance of the tumor protease cathepsin D in mammary carcinomas as a tumor marker. We present a systematic overview based on a selective Medline search. Cathepsin D is expressed in mammary carcinomas and exhibits higher expression in invasive ductal carcinomas compared with lobular carcinomas. Nodal positive carcinomas showed reduced cathepsin D expression compared to lymph node metastases, and increased expression has been observed in hormone-receptor negative tumors. Thus, the expression of cathepsin varies between the two histological types. Increased cathepsin-D expression in acinar affection has also been described. The lack of an association of cathepsin D with known prognostic factors such as CA15-3, ERalpha and ERbeta does not prevent it from being using as a tumor marker. Cathepsin has already been used along with other genes as a prognostic parameter for carcinoma patients in gene arrays.

Staining of MUC1 in ovarian cancer tissues with PankoMab-GEX detecting the tumour-associated epitope, TA-MUC1, as compared to antibodies HMFG-1 and 115D8.

PankoMab-GEX is a novel humanized and glycooptimized antibody, which recognizes a novel specific tumour epitope of MUC1 (TA-MUC1). The aim of this study was to evaluate PankoMab-GEX binding to a variety of ovarian cancer specimens (n=156) and to normal ovarian tissue. In addition, PankoMab-GEX staining was compared to that of the well-known anti-MUC1 antibodies HMFG-1 and 115D8. PankoMab-GEX showed positive reactivity in serous (100% of cases, mean IRS 8.23), endometrioid (95% of cases, mean IRS 6.40), mucinous (58% of cases, mean IRS 4.17), and clear cell (92% of cases, mean IRS 7.58) carcinomas. In contrast to HMFG-1, healthy ovarian tissue was not recognized by PankoMab-GEX. Staining with antibody 115D8 was increased with staging. Cytoplasmic PankoMab-GEX staining increased with tumour grade, but no correlation was found with staging. Univariate Kaplan-Meier analysis revealed a tendency of reduced survival of patients with high expression of TA-MUC1. The findings are encouraging with respect to a potential use of PankoMab-GEX as a new therapeutic antibody for the treatment of ovarian cancer patients.

Expression of different carbohydrate tumour markers and galectins 1 and 3 in normal squamous and malignant epithelia of the upper aaerodigestive tract.

AIM: Tumour markers hold a great relevance in the diagnosis and the follow-up treatment of different kinds of human carcinoma. Although head and neck cancer occurs frequently, there is still lack of appropriate tumour markers. Our investigation on the expression of sialyl Lewis A (CA19-9) in laryngeal carcinomas, consists of systematical analysis of oncofetal carbohydrates and of galectins 1 and 3 in different normal and malignant tissues of the aerodigestive tract. MATERIALS AND METHODS: Paraffin-embedded sections of normal tongue, vocal cord, larynx, pharynx and epiglottis, representing normal control tissue and laryngeal cancer tissue were incubated with monoclonal antibodies against sialyl Lewis A and X (sLeA and X), Lewis Y (LeY), the Thomsen-Friedenreich (TF) antigen and galectin 1 and 3 (Gal-1 and -3). A staining reaction was carried out with ABC-peroxidase and diaminobenzidine (DAB). Tissue of breast cancer was used as a positive control. Mouse IgM, as isotype control antibody, was used as a negative control. Semi quantitative evaluation was carried out double-blinded, by two independent investigators, including a pathologist. RESULTS: Squamous epithelia of all investigated normal tissues of the aerodigestive tract show nearly the same pattern. Most impressive findings are the very weak expression of Gal-1 and the total absence of the TF antigen. Laryngeal cancer reveals high amounts of sLeA, Gal-1 and the TF antigen. CONCLUSION: On the basis of our findings in normal tissue of the aeradigestive tract, these three markers qualified as potential tumour markers for carcinoma of the aerodigestive tract. In particular, the high expression of TF in cancer tissue and its absence from the normal tissue is promising for its establishment as a new tumour marker in this field.

Determination of MUC1 in sera of ovarian cancer patients and in sera of patients with benign changes of the ovaries with CA15-3, CA27.29, and PankoMab.

AIM: Mucin 1 (MUC1) is a high molecular weight transmembrane glycoprotein with unique properties which is used as a tumour marker in sera of ovarian cancer patients. The common test kit for the cancer antigen 15-3 (CA15-3) is not sufficient for the discrimination between sera from healthy individuals and sera from patients with benign changes of the ovaries. In this study, the newly developed anti-MUC1 antibody PankoMab was tested in normal and patient sera with an ELISA, and the obtained data were compared against data from experiments using the commercial kits for CA15-3 and CA27.29. MATERIALS AND METHODS: Sera of 123 patients diagnosed with benign or malignant changes of the ovaries were obtained before surgery. CA15-3 was analysed with an automated ELISA system (Immulite 2000). CA27.29 was measured with the ST AIA-PACK CA27.29 for the AIA-600II-Analyzer (Tosoh Bioscience, Belgium). The release of MUC1 fragments carrying the TA-MUC1 epitope was analysed with an ELISA using the PankoMab antibody. RESULTS: Using the already established markers CA15-3 and CA27.29, significant differences between benign and malignant changes of the ovaries were found. The same result was obtained with the newly developed TA-MUC1 test. In contrast to CA15-3 and CA27.29, however, the median of TA-MUC1 was lower in sera from patients with ovarian cancer compared to sera from patients with benign diseases of the ovary. However, sera of patients with benign ovarian diseases had significantly higher TA-MUC1 values compared to sera of healthy individuals. The risk score of TA-MUC1 achieved an area under the curve (AUC) of 78.4% in receiver operating characteristic (ROC) curves and a sensitivity of 37% for the prediction of ovarian disease, at 95% specificity. CONCLUSION: In this study we employed an additional marker for MUC1 which recognizes a more tumour-specific MUC1 epitope (TA-MUC1). We obtained results showing significant differences between detection in benign and malignant ovarian diseases. Although the mean MUC1 values were elevated in sera of patients with ovarian cancer compared to values of patients with benign cysts, by using all three test systems, a different result was found by analysing the median TA-MUC1 values. PankoMab could be a useful, additional tool for obtaining conclusive information on the transformation process from benign to malignant state in ovarian tissues.

Induction of G protein-coupled estrogen receptor (GPER) and nuclear steroid hormone receptors by gonadotropins in human granulosa cells.

Estradiol and progesterone mediate their actions by binding to classical nuclear receptors, estrogen receptor α (ERα) and estrogen receptor ß (ERß) and progesterone receptor A and B (PR-A and PR-B) and the non-classical G protein-coupled estrogen receptor (GPER). Several animal knock-out models have shown the importance of the receptors for growth of the oocyte and ovulation. The aim of our study was to identify GPER in human granulosa cells (GC) for the first time. Moreover, the effect of different doses of gonadotropins on estrogen and progesterone receptors in the human ovary should be investigated as follicle stimulating hormone (FSH) and luteinizing hormone (LH) are also responsible for numerous mechanisms in the ovary like induction of the steroid biosynthesis. Human GC were cultured in vitro and stimulated with different doses of recombinant human FSH or LH. Receptor expression was analyzed by immunocytochemistry and quantitative real-time RT-PCR. GPER could be identified for the first time in human GC. It could be shown that high concentrations of LH increase GPER protein expression. Furthermore FSH and LH increased ERß, PR-A and PR-B significantly on protein level. These findings were verified for high doses of FSH and LH on mRNA level. ERα was not affected with FSH or LH. We assume that gonadotropins induce GPER, ERß and PR in luteinized granulosa cells.

Expression of the carbohydrate tumor marker Sialyl Lewis a (Ca19-9) in squamous cell carcinoma of the larynx.

BACKGROUND: The clinical relevance of the carbohydrate antigen Sialyl Lewis a (SLea) as a serum tumor marker in diagnosis and follow-up treatment is unquestioned in a broad spectra of human carcinomas. Overexpression of this antigen is combined with poor prognosis and malignant relapse. The aim of our study was the systematic investigation of SLea expression in squamous cell carcinoma of the larynx versus normal and phlogistic tissue. MATERIALS AND METHODS: Paraffin-embedded sections of normal, phlogistic and squamous cell carcinoma tissue were incubated with a monoclonal antibody against SLea. The staining reaction was performed using ABC-Peroxidase and DAB. As a positive control tissue of breast cancer was used and the negative control was performed with unspecific mouse IgM. Semiquantitative evaluations were carried out double-blinded by two independent investigators, including a pathologist. RESULTS: A very faint expression of SLea (Ca19-9) in normal laryngeal tissue, a moderate upregulation in phlogistic tissue and a dramatic upregulation in some types of squamous cell carcinoma of the larynx were observed. Laryngeal cancer is the most common cancer of the upper aerodigestive tract. Most cases of laryngeal cancer are squamous cell carcinoma and can be classified into: well differentiated (more than 75% keratinization), moderately differentiated (25-75% keratinization), and poorly differentiated (<25% keratinisation) carcinomas. CONCLUSION: The results of this study indicate that SLea is a potential tumor marker in carcinoma of the larynx.

Expression of inhibins in the endometrial carcinoma cell line RL-95-2 after stimulation with cortisol and estradiol.

UNLABELLED: Inhibins (INH) are dimeric glycoproteins composed of an alpha-subunit (INH-alpha) and one of two possible beta-subunits (INH-betaA or -betaB), with substantial roles in human reproduction and in endocrine-responsive tumours. The aim of the present study was the determination of the frequency and tissue distribution patterns of the inhibin/activin subunits in endometrial carcinoma cells of the cell line RL-95-2 after stimulation with estradiol and cortisol compared to unstimulated controls. MATERIALS AND METHODS: Cells of the endometrial carcinoma cell line RL-95-2 were grown on quadriperm tissue slides and incubated with different concentrations (0.1 and 0.01 micromol/ml) of estradiol or cortisol. Expression of INH-alpha, betaA and betaB was analysed by immunocytochemistry with specific monoclonal antibodies directed against the inhibin subunits. RESULTS: Expression of INH-alpha and -betaB was higher in cortisol-stimulated RL-95-2 cells, whereas INH-betaA expression was lower. In contrast to these, INH-betaB expression was increased by estradiol while INH-alpha and -betaA were unchanged under estradiol treatment. CONCLUSION: Expression of INH-subunits in RL-95-2 cells was described. Cortisol and estradiol showed an influence on INH expression. The RL-95-2 cell line could act as a useful model for the investigation of INH regulation, particularly for endometrial cancer.

Expression of the carbohydrate tumour marker SLeX, SLeA (CA19-9), LeY and Thomsen-Friedenreich (TF) antigen on normal squamous epithelial tissue of the penis and vagina.

BACKGROUND: Sialyl Lewis x (SLeX), sialyl Lewis a (SLeA), Lewis Y (LeY) and the Thomsen-Friedenreich (TF) antigen are carbohydrate motifs that mediate the adhesion between tumour cells and the endothelium. These antigens are usually not expressed in non-malignant tissue. Overexpression of SLeX and SLeA is combined with poor prognosis and malignant relapse. In this study, we analysed the combined expression of SLeX, SLeA, LeY and TF in normal squamous epithelium tissue of the penis shaft, glans and foreskin and in addition of the vagina and vulva. MATERIALS AND METHODS: Paraffin-embedded slides of vaginal tissue (8), vulva tissue (8) and penis shaft (8) and glans tissue (8) were fixed and incubated with monoclonal antibodies against SLeX (IgM), SLeA (IgM), LeY (IgM) and TF (IgM). Staining reaction was performed with ABC reagent. The intensity of immunohistochemical reaction on images of the slides was analyzed using a semiquantitative score. RESULTS: Strong focal expression of both sialyl Lewis antigens was found in the uretra of the penis shaft and on epithelial tissue of the glans, and permanent moderate expression of SLeX and SLeA in squamous epithelial tissue of the vagina. Moderate expression of TF was observed in male squamous epithelial tissues of the glans and foreskin and faint expression of TF was found in vulval epithelial tissue. Faint expression of Le Y was observed in female vulval epithelial tissue. CONCLUSION: Expression of SLeX, SLeA, LeY and especially of the TF antigen in normal non malignant epithelial tissue is surprising and can be explained by the function of this tissue in human reproduction. In addition, moderate TF expression seems to be restricted to epithelial tissue of the penis glans and foreskin.

Binding of galectin-1 (gal-1) to the Thomsen-Friedenreich (TF) antigen on trophoblast cells and inhibition of proliferation of trophoblast tumor cells in vitro by gal-1 or an anti-TF antibody.

Galectin-1 (gal-1), a member of the mammalian beta-galactoside-binding proteins, recognizes preferentially Galbeta1-4GlcNAc sequences of several cell surface oligosaccharides. We demonstrate histochemically that the lectin recognizes appropriate glycotopes on the syncytiotrophoblast and extravillous trophoblast layer from second trimester human placenta and on BeWo chorion carcinoma cells. Gal-1 binding to BeWo cells was diminished by the Thomsen-Friedreich (TF)-disaccharide (Galbeta1-3GalNAc-) conjugated to polyacrylamide (TF-PAA). Gal-1 also inhibited BeWo cell proliferation in a concentration-dependent manner. Similar antiproliferative effects were also observed with an anti-TF monoclonal antibody (mAb, A78-G/A7). Therefore, we conclude that ligation of Galbeta1-4GlcNAc and Galbeta1-3GalNAc epitopes on BeWo cells may have regulatory effects on cell proliferation.

Induction of apoptosis in human breast cancer and trophoblast tumor cells by galectin-1.

Galectin-1 (gal-1), a member of the mammalian beta-galactoside-binding proteins, preferentially recognizes Galbeta1-4GlcNAc (LacNAc) sequences of oligosaccharides associated with several cell surface glycoconjugates. As demonstrated histochemically, gal-1 recognizes appropriate glycoepitopes on human breast cancer cells (MCF7) and on human chorionic carcinoma cells (BeWo). Gal-1 is expressed in many malignant and normal tissues. A high level of expression is found in lymphatic organs, which feature high rates of apoptosis. Furthermore, it is known that galectin-1 can initiate T cell apoptosis. In this study, we examined the apoptotic potential of gal-1 in vitro on MCF7 and BeWo cells. After growing both cell lines on chamber-slides for three days, apoptosis was induced by incubation with 30 microg gal-1 per ml serum-free medium for 6, 9 and 20 hours. To avoid false increased rates of apoptosis by deletion of FCS, all approaches were done with and without FCS. Apoptotic cells were detected by in situ nick translation. The rate of apoptosis was determined by counting 1500 cells per chamberslide. The normal rate of apoptosis ranged between 0.1% and 0.3%. The incubation of both cell lines with 30 microg/ml gal-1 in serum-free medium for 6 and 9 hours marginally raised the number of apoptotic cells. An increase of apoptosis was only shown by additional stimuli like hyperthermia, removal of CO2 and FCS for 20 hours. Impressing findings were manifested in an older passage of BeWo cells, in which only omission of FCS caused apoptotic rates for up to 25% after 6 hours. The presence of mycoplasma in this BeWo passage was shown by PCR. Our results demonstrated, that galectin-1 shows apoptotic potential in both the epithelial tumour cell lines examined only with additional stress stimuli.

Binding of galectin-1 (gal-1) on trophoblast cells and inhibition of hormone production of trophoblast tumor cells in vitro by gal-1.

Galectin-1 (gal-1), a member of the mammalian beta-galactoside-binding proteins, recognizes preferentially Galbeta1-4GlcNAc sequences of oligosaccharides associated with several cell surface glycoconjugates. As demonstrated histochemically, the lectin recognizes appropriate glycoepitopes on the syncytiotrophoblast and on chorionic carcinoma cells (BeWo). Freshly isolated trophoblast cells and trophoblast tumor cells Jeg3 did not bind gal-1. BeWo cells in contrast to Jeg3 form a syncytium in vitro and synthesize progesterone as well as hCG. BeWo cells were used as an approach to study the effects of gal-1 on hormone production. The lectin decreased cellular hCG and progesterone production as well as hCGbeta gene transcription as measured by real-time RT-PCR. Gal-1 mediated inhibition of cellular progesterone production was reduced in the presence of a Thomsen-Friedenreich (TF)-polyacrylamide conjugate. Inhibition of cellular hCG and progesterone production was also induced by anti-TF monoclonal antibodies. The results demonstrate that ligation of Galbeta1-4GlcNAc and Galbeta1-3GalNAc (TF) epitopes on BeWo cells may have regulatory effects on hCG and progesterone production.